Post-Polio Syndrome: Pathophysiology and Clinical Management
Anne Carrington Gawne and Lauro S. Halstead
XI. DIFFERENTIAL DIAGNOSIS AND REHABILITATION MANAGEMENT.
In general, we have found that patients most at risk for developing new problems are those who experienced more severe polio at onset, although it is not unusual to see patients with typical post-polio symptoms who had seemingly very mild polio with excellent clinical recovery. Most commonly, the onset of these new problems is insidious, but in many persons they may be precipitated by specific events such as a minor accident, fall, period of bed rest, or weight gain. Characteristically, patients state that a similar event experienced several years earlier would not have caused the same decline in health and function. Likewise, new problems may begin when coexisting medical problems, such as diabetes, develop or worsen.
The symptoms experienced by polio survivors, unfortunately, are fairly common and nonspecific. The lack of specificity and a characteristic cluster of symptoms have led some observers to question both the validity of the symptoms and the existence of a diagnosis of post-polio syndrome. Until a pathognomic test is found, this dilemma will undoubtedly persist. However, health professionals who have become experienced in this field in recent years generally agree there are definite qualitative features of these symptoms that are reasonably characteristic. The differential diagnosis of symptoms experienced by persons with a history of polio is complex, and they must be evaluated in a symptom by symptom manner. We review these symptoms, their differential diagnosis, and outline an approach to the evaluation and rehabilitation management that we have found to be successful.
A. Weakness and Functional Loss.
1. Differential Diagnosis.
Because of the importance of weakness as a cardinal symptom of motor neuron dysfunction and post-polio changes in general, it should be addressed early and one should make the differentiation between post-polio syndrome as a cause of new weakness or other causes of new weakness. New weakness may appear in muscles previously affected and/or muscles believed to be previously spared. The weakness is usually most prominent, however, in the muscles most severely involved in the initial illness. Diminished functional capacity tends to parallel the muscle weakness and can be quite dramatic if functional reserve was marginal. One of the characteristics of many polios was their ability to appear "normal" or function at an extraordinarily high level of performance on relatively few good muscle groups. This was possible because of the random, scattered nature of the motor deficits and the body's uncanny ability to compensate with unconventional muscle and joint function. In this situation then, late onset weakness of a critical muscle often leads to disruption of a delicate balance that has been maintained for years, leading to a disproportionate amount of functional loss. Persons with involvement of one or both legs may have increased difficulty in walking, standing, climbing stairs, or other endurance activities. individuals with presumably normal upper extremities who have been "walking" on their arms with crutches for years may find that ambulating, transfers, driving a car, or even dressing are more taxing and the time to recover takes longer than it used to.
When patients present with complaints of "new weakness", the first task the practitioner needs to do is differentiate between true weakness (a loss in muscle strength) and other synonymous terms the patient may be referring to, such as lassitude, fatigue, lack of energy, and languor. Whereas the polio patient may also experience these symptoms, they are complaints of fatigue, not progressive muscle weakness. If possible, objective muscle testing with a myometer or isokinetic system should be done to establish a reliable baseline.[91-93] This baseline is essential for monitoring changes in strength in the future. If there is a history of new weakness (often revealed as decreased endurance with diminished function) combined with objective changes, the major differential diagnoses include focal neurological disease such as a radiculopathy, focal compressive neuropathy, or spinal cord lesion and medical causes of neuropathy such as diabetes, thyroid disease, uremia, alcohol, toxins, and, uncommonly, hereditary neuromuscular disease. In most cases, history and a physical alone can make this distinction; however, when necessary, laboratory or electrodiagnostic data may be needed to clarify the appropriate diagnosis. Once other causes are ruled out, an attempt should be made to distinguish the etiology of this weakness (disuse vs. overuse), so that appropriate recommendations regarding exercise and activity can be made.
For patients with new weakness (with or without atrophy), the major differential confronting the clinician is to distinguish between neurogenic weakness due to polio and disuse weakness caused by diminished activity. Although the distinction is not always readily apparent in the clinical setting, when new neurogenic weakness is present a careful history can usually elicit a pattern of decreased strength, endurance, and function despite attempts to maintain the usual level and intensity of activity. Routine, daily activities that require repetition or sustained contractions, such as walking, climbing stairs, standing, or pushing a wheelchair can sometimes provide a semi-quantitative picture of new weakness when current performance is compared with similar activities in the past, for example, number of stairs climbed without difficulty 1, 3, or 5 years ago vs. now. When the presence of new neurogenic weakness is in doubt, a trial of carefully monitored exercise is indicated to exclude the possibility of disuse weakness.
As indicated earlier, we feel the workup for new neurogenic weakness should include an EMG/NCS. Although electrodiagnostic studies even in the most skilled hands have their limitations, they provide a necessary screening tool to help exclude some of the more common causes of neurogenic weakness in this population. Specifically, EMG studies can indicate the presence of radiculopathies from disc disease or other causes and help differentiate old polio from other neuromuscular disorders such as adult onset spinal muscular atrophy and myopathies. Nerve conduction studies can identify the presence of localized compression neuropathies as well as generalized peripheral neuropathies. Follow-up laboratory and imaging studies can help clarify the underlying etiology suggested by the electrodiagnostic exam and reveal other causes for weakness such as occult tumors, toxic metal exposure, and endocrine disorders. New weakness may appear in muscles previously affected and muscles believed to be previously spared. The weakness is usually most prominent, however, in the muscles most severely involved initially. Diminished functional capacity tends to parallel muscle weakness and can be quite dramatic if functional reserve was marginal. This occurs because of the functional compensations that are made early within the recovery period.
There has been a controversy about the management of new weakness with exercise in the post-polio patient because the pathophysiology of PPS remains unclear. Traditional therapy such as exercise may cause further weakness, so it must be used cautiously. As there is now a considerable body of literature on this subject -- some of it contradictory -- we will provide a quick review of what is known before proposing specific recommendations.
One of the first formal isotonic strengthening programs for patients with a history of polio was described in 1948 by Delorme and Watkins, who applied the principle of progressive resistive exercises (PREs) in 19 post-polio subjects. In the end, 17 of 27 muscle groups demonstrated gross gains in strength measured with MMT. Muscle power in 15 of 27 quadriceps muscles doubled or more than doubled as measured by a spring scale. All except three muscles showed an increase in work capacity. In 1950, Gureswitsch evaluated 13 subjects who were in the initial phases of recovery from their polio. They exercised with a modification of Delorme's protocol. After training, both muscle strength and endurance increased 50%.
In the early 1980s, specific exercise studies were carried out for survivors with PPS. In 1984, Feldman and Soskolne developed an exercise protocol they described as "non-fatiguing strengthening exercises" for a population of six subjects with post-polio symptoms. This was performed three times weekly for a period of 3 to 6 months. They found that by using this routine for at least 24 weeks, 14 muscles (46%) got stronger, 17 (53%) showed no change, and 1 muscle got weaker, as measured by myometry. There was no relationship between the initial weakness and improvement in strength.
Grimby and Einarsson reported an isokinetic exercise program for 12 post-polio subjects, including nine with symptoms of PPS, in 1987. These exercises were performed for a total of 6 weeks. Only one leg was trained and the other served as a control. There were significant strength gains in the trained leg. The investigators concluded that increases in strength might be explained through both muscular as well as neural adaptations. In 1991, Einarsson used a similar protocol for muscle conditioning of knee extensors in 30 post-polio subjects. This was performed three times a week for 6 weeks. There was a significant improvement in knee extension strength, with no change in the strength of the knee flexors. These changes were also associated with subjective improvements in functional tasks and general well-being.
Also in 1991, Fillyaw and colleagues used Delorme's training program with 17 PPS subjects. The quadriceps or biceps were exercised, with the contralateral extremity used as a control. Three sets of 10 repetitions with a 5-min rest between sets were performed every other day. Sixteen of 17 subjects demonstrated significant strength gains, but there was no evidence of increased endurance. They cautioned patients should undergo periodic quantitative muscle testing under the supervision of a physical therapist to avoid overwork weakness.
Agre and Rodriguez have described an exercise technique known as "pacing", mixing periods of exercise with periods of rest, in post-polio subjects.[104-106] They found when subjects paced themselves they had less evidence of muscle fatigue, increased capacity to perform work and increased ability to recover strength after activity.
In addition to strengthening programs, studies were also done to determine the cardiovascular fitness of post-polio survivors and to assess their response to a cardiovascular training program. In 1985, Owen and Jones evaluated the cardiovascular endurance of 21 subjects in an EKG-monitored, symptom-limited graded exercise test. They found that the subjects had an average maximum fitness level of 5.6 metabolic equivalents (METS), indicative of severe deconditioning. They proposed an exercise program as follows: intensity of 65 to 80% of reserve HR (maximum HR-resting HR), a duration of 15 to 30 min, and a frequency of three to five times per week on alternate days.
In 1987, Alba and co-workers evaluated the work capacity of 35 subjects, including 33 that were complaining of new symptoms. Parameters evaluated included muscle strength using MMT, body weight, maximum METS, maximum heart rate (Hrmax), maximum oxygen uptake (VO2 max), and vital capacity (VC). Significant findings included a decreased VC, especially in those who smoked or had a history of respiratory involvement. There was also a decreased Hrmax, decreased maximal cardiac output, and decreased work capacity. She recommended that post-polio survivors partake in any repetitive activity that appealed to them, if it was considered "safe" and recommended stopping the activity if it caused "undue pain, muscle fatigue or a sense of weakness" that required more than the usual time to recover.
Dean and Ross examined the effects of a modified exercise program in three post-polio subjects in 1988. Each subject met the diagnostic criteria for PPS and was ambulatory without assistive devices. Using one subject as an untrained control, the other two walked on a treadmill three times a week at a submaximal rate for a total of 8 weeks, advancing their walking duration from 22 to 31 min. The rating of perceived exertion (RPE) was monitored using a 1 to 10 scale, and pain was monitored using a 1 to 4 scale. An attempt was made to keep the RPE below 2 (light). After training, on submaximal testing, both the trained subjects demonstrated reductions in VO2, HR, blood pressure (BP), RPE, and energy cost at similar work loads compared with the pretest, while the untrained subject showed no change. There was no apparent effect of training on pulmonary function. The mechanism for the change was felt to be both cardiovascular conditioning as well as muscle adaptation.
In 1989, Jones and colleagues evaluated the cardiorespiratory responses to aerobic training in 16 post-polio subjects who participated in a 16-week exercise program. Baseline tests, including resting HR and BP, HRmax, BPmax, VO2, and expiratory volume (Ve), were performed on a bicycle ergometer. Subjects were divided into exercise and control groups. The subjects exercised three times a week for a period of 15 to 30 minutes using a predetermined target HR. Significant results on post-test included an improvement in the total exercise time, total work per time, VO2, and Vemax within the exercise group. In 1992, in a similar study Kriz and colleagues examined the effects of an upper-extremity arm ergometry program in 29 post-polio subjects. The exercise group participated three times a week in a 16-week training program with a heart rate of 70 to 75% HR reserve, with 1 d of rest between exercise sessions. After the 16-week program, the exercise group showed significant improvement in VO2 max, Vemax, power, and exercise time. None of the subjects in the exercise group developed problems with pain or overuse.
In summary, although it is true that individuals with a history of polio may develop new weakness many years after the original episode, it has been shown that many can improve both muscle strength and cardiovascular endurance from a well-planned training program. There appears to be positive benefits regardless of whether the muscle group is with or without new weakness. The type of exercise program needs to be selected according to both the needs of the individual and the resources available. An isometric program is of benefit in those who have less than antigravity strength, a painful joint, or a joint immobilized in a cast due to surgery or a fracture. An isotonic program is more appropriate for a home exercise program for a non-painful joint with greater than antigravity strength. An isokinetic program can be used when the equipment is available and the muscles have greater than antigravity strength. While the long-term safety of a strenuous strengthening program on muscle that has been severely affected is not known, the positive effects of exercise on other systems, including cardiovascular and respiratory systems are clear. Therefore, it can be concluded that a carefully monitored program is beneficial for most individuals with a history of polio. It is also possible that many of the secondary symptoms such as generalized fatigue can be reduced as patients become conditioned and are able to perform similar amounts of work with less expenditure of energy. An ideal cardiovascular program should exercise the muscles least affected by polio in order to get maximum cardiovascular benefits, while avoiding overuse or secondary degenerative effects on the more affected extremities. For instance, if the legs are the more involved limbs, then the arms can be used in a more strenuous program. The exercise program should be initially supervised by a physical therapist in order to teach proper techniques, including the monitoring of HR and RPE. As with all exercise programs, a warmup followed by gentle stretching should be done to improve flexibility and reduce the possibility of injury. Both aerobic and strengthening exercises can be done. Finally, after exercising, a cooldown period should take place. The type of activity should be one that the participant enjoys to minimize lack of interest and potential for drop out.
In order to prescribe the safest and most appropriate exercise program for post-polio patients in our clinic, we have developed a new limb-specific muscle classification system called the National Rehabilitation Hospital (NRH) Post-Polio Limb Classification.[41,113] A standardized taxonomy provides a means of establishing a common language that can be used by clinicians and researchers alike. This makes it possible to establish an objective baseline for each muscle and limb before initiating treatment and then apply a systematic, rational protocol appropriate for the degree of polio involvement. When results of various protocols and clinical trials are compared, we have a better basis for understanding their efficacy and their applicability to other patients or limbs with similar involvement. It can be used to give recommendations regarding activity, prognosis, and need for assistive equipment.
To classify a limb, a combination of history, physical exam, and EMG is used. Key elements of the history include both remote and recent history of weakness. Physical examination focuses on strength, sensation, and reflexes. On electrodiagnosis in addition to evaluating for specific clinical conditions, a screening examination is performed. It includes nerve conduction studies (NCS) of bilateral median and sensory nerves, as well as needle examination of at least three muscles in each extremity.[94,114] Following the EMG, each muscle is classified separately and the limb is classified according to the most severely involved muscle. Table 7 summarizes this classification.
The National Rehabilitation Hospital (NRH) Post-Polio Limb Classification
|NRH Class I||No Clinical Polio
|NRH Class II||Subclinical Polio
|NRH Class III||Clinically Stable Polio
|NRH Class IV||Clinically Unstable Polio
|NRH Class V||Severely Atrophic Polio
NRH Class I muscles (no clinical polio) have no history of past or new weakness. Strength ranges from good to normal, and there is no atrophy, sensory, or reflex changes. On monopolar EMG there is no evidence of muscle membrane instability such as fibrillation potentials (fibs) or positive sharp waves (PSW). The MUAPs are normal in size and configuration with normal recruitment. Single fiber EMG or muscle biopsy may show evidence of old anterior horn cell disease if extensive testing is carried out; however, in a clinical setting, this is not feasible. The objective of the exercise program for Class I muscles or limbs is to increase muscle strength and cardiovascular endurance. Exercise recommendations consist of a strengthening program with PREs as described by DeLorme. These muscles can be used selectively in an aerobic program to improve cardiovascular conditioning following the American College of Sports Medicine (ACSM) recommendations for frequency and duration. A typical program might include the following: exercise three to four times a week for a period of 15 to 30 min at a heart rate of 60 to 80% of HRmax or an equivalent of 8 to 9 METS (Table 8).
Table of Metabolic Equivalents (METS) (Ref. 113.)
|1 - 2 METS
Doing seated ADLs (eating, performing facial hygiene, resting)
Doing seated recreation (sewing, playing cards, painting)
Doing seated occupational activities (writing, typing, doing clerical work)
|2 - 3 METS
Standing ADLs (dressing, showering, shaving, doing light housework)
Standing occupation (mechanic, bartender, auto repair)
Standing recreation (fishing, playing billiards, shuffleboard)
Walking 2.5 mph
Bike riding 5-6 mph
|4 - 5 METS
Doing heavy housework (scrubbing floor, hanging wash)
Canoeing, golfing, playing softball, tennis (doubles)
Social dancing, cross country hiking
Swimming 20 yards/min
Walking 4 mph (level), 3 mph (5% grade)
Bike riding 10 mph
|6 - 7 METS
Heavy gardening (digging dirt, lawn mowing, hoeing)
Skating, water skiing, playing tennis (singles)
Stair climbing (<27 ft/min)
Swimming 25 yards/min
Walking 5 mph (level), 3.5 mph (5% grade)
|8 - 9 METS
Active occupation (sawing wood, digging ditches, shoveling snow)
Active recreation (downhill skiing, playing ice hockey, paddleball)
Bike riding 12 to 14 mph, stair climbing (27 ft/min)
Swimming 35 yards/min
Walking 9 mph, 3 mph (15% grade)
NRH Class II muscles (subclinical polio) have no history of past or new weakness, or if they were affected they have fully recovered. Strength is good to normal, sensation and reflexes are normal. EMG is consistent with anterior horn cell disease (AHCD). The goal of the exercise program for Class II extremities is to increase strength in those muscles in the good range and maintain normal strength in the remainder. If other extremities are more severely affected, Class II extremities can be used to improve cardiovascular endurance using ACSM guidelines for frequency and HR. However, the session should be paced, with exercise periods of 4 to 5 min and rest breaks of 1 min. The frequency of exercise should also be paced, alternating exercise and rest days. As a training effect develops and the individual is able to perform a similar workload with less fatigue, both the amount of resistance used and the frequency and duration of the exercise can be altered to meet the changing increases in strength.
NRH Class III muscles (clinically stable polio) have a remote history of weakness with some improvement and no complaints of new weakness. On physical examination, the strength ranges from fair to good. Sensation is normal and reflexes are normal or decreased proportional to the muscle strength. EMG shows evidence of old AHCD. These muscles and limbs along with those in Class I and II represent those previously described as "asymptomatic". The goal for Class III extremities is to at least maintain strength and if possible gain strength in those muscles that are deconditioned. Recommendations include strengthening exercises, similar to Class II, with pacing. Strength should be carefully monitored and the program modified if weakness develops. Aerobic activities for Class III extremities with strength greater than or equal to antigravity are similar to those for Class II extremities. For those extremities with less than antigravity strength, cardiovascular exercises in the 4 to 5 MET range are appropriate, pacing 2 to 3 min of activity with 1 min rest, three times a week, on alternating days. For limbs with degenerative joint disease (DJD), non-weight-bearing exercises such as a pool program are preferred.
NRH Class IV muscles (clinically unstable polio) are those that are developing new weakness and sometimes atrophy. Sometimes these limbs or muscles were described in the literature as "symptomatic". They are usually weaker, with less dynamic and isometric strength than Class III. Sensation is normal, old atrophy usually is present, and reflexes are decreased. EMG findings are largely similar to Class III, as indicated previously. The goal in this class is to prevent further weakness, so we recommend first decreasing activity if overuse is suspected. If disuse is suspected, or rest does not help, then an exercise program is begun. A nonfatiguing exercise program would be appropriate for strengthening. Because many muscles may have less than antigravity strength, exercises should be done in a gravity-eliminated position or in a pool. Muscle strength is carefully monitored. This program should be done no more than three times a week and modified if symptoms of pain, new weakness, or fatigue develop. For cardiovascular conditioning we generally recommend that they be used in ADLs only. As we have found that many of our patients have less affected upper extremities, we frequently advise our patients to do a cardiovascular exercise using only their arms, such as swimming or arm ergometry. For those limbs with severe weakness, we recommend avoiding weight bearing by using an assistive device, wheelchair, or motorized scooter. Bracing is frequently necessary.
NRH Class V muscles (severely atrophic polio) are those that are originally affected with severe weakness and little improvement. New weakness may be present. On physical examination they are extremely weak (trace to poor) with marked atrophy, no sensory changes, and are areflexic. On EMG there is decreased insertional activity, few fibs or PSW, little to no MUAPs, with variable amplitude, increased polyphasics, and markedly decreased recruitment. These limbs cannot be exercised; however, a passive range of motion program is suggested.
Table 9 shows the result of classification of 400 limbs in 100 consecutive post-polio patients evaluated in our clinic. The distribution of our findings in both the upper and lower extremities are detailed in Figures 10 and 11. Note the higher percentage of upper extremities in Classes I and II with a higher percentage of lower extremities in Classes III, IV, and V.
It has been demonstrated that people with a history of polio can improve muscular strength and endurance as well as cardiovascular conditioning in individualized, carefully monitored exercise programs. With this in mind, in conjunction with an appropriately trained professional, a prescription for a rational exercise program can be developed using this limb-specific classification system with the goal that virtually all post-polio individuals can more safely enjoy many of the additional positive benefits that regular exercise can bring.
NRH Limb Classification Of 100 Consecutive Post-Polio Outpatients N = 400
|NRH Class||Upper Extremity||Lower Extremity||Total
|FIGURE 10. Distribution of upper extremity limbs
by NRH Limb Classification in 100 consecutive post-polio patients (N = 200).
|FIGURE 11. Distribution of lower extremity limbs
by NRH Limb Classification in 100 consecutive post-polio patients (N = 200).
1. Differential Diagnosis.
Fatigue is often a nonspecific complaint, with a variety of possible etiologies. The fatigue is sometimes focal but more typically generalized and is usually described as overwhelming exhaustion or flu-like aching accompanied by a marked change in the level of energy, endurance, and sometimes mental alertness. Frequently, patients will complain of fatigue when the problem is actually new weakness and vice versa. In a study of polio survivors and healthy controls, Berly found that both groups described fatigue as "tiredness and lack of energy", while polio survivors were significantly different from controls in describing their fatigue as "increasing physical weakness", "increasing loss of strength during exercise", and "heavy sensation of the muscles". The fatigue usually occurs on a daily basis and progresses during the day. It is typically brought on by an accumulation of activities that had been carried out previously on a daily basis without special effort or noticeable sequelae. Late in the afternoon or early evening it peaks, and it is described by some people like "hitting a wall". When this occurs, it becomes necessary for individuals to stop what they are doing, rest, and, if possible, take a short nap. Of all the new health problems, this is often the most distressing because it imposes limits on people's lives without obvious objective changes that others can easily identify.
Fatigue that occurs after awakening may reflect sleep disturbances that are commonly due to musculoskeletal pain but may also reflect nocturnal pulmonary abnormalities. Fatigue that tends to last all day is atypical of PPS and should make one consider other diagnoses. The differential for fatigue is extensive but the considerations should include such disorders as other medical diseases, including anemia, chronic infections, collagen disorders, thyroid disease, diabetes, or cancer. Depression can also cause symptoms of fatigue. Fatigue can result from a number of medications, both prescription medications such as beta blockers or sedatives, or over-the-counter medications such as antihistamines. Deconditioning and obesity can also contribute to feelings of fatigue. Once these have been ruled out, then a careful evaluation of lifestyle is needed. Many patients are both active and competitive, awakening early, then working one job and sometimes two before coming home to work in the home and getting to sleep late. No matter what their vocation or avocation, many patients sustain a level of activity more strenuous than their strength and endurance allows. Because of disproportionate levels of activity, we have found it useful to have patients keep a diary both of their sleep and daytime activities, as well as the response to their schedule.
Bruno and colleagues have suggested that post-polio fatigue is caused by poliovirus-induced damage to the reticular activating system (RAS).[117-119] Acutely, drowsiness, lethargy, disorientation, and apathy were noted in poliovirus patients.[120,121] The reports of drowsiness, lethargy, fatigue, and fleeting attention in patients with acute polio virus are similar to the symptoms of decreased attention and fatigue that post-polio patients are now experiencing. Such damage would impair the ability of the RAS to activate the cortex and would generate problems with attention and concentration that polio survivors describe as "brain fatigue". For this hypothesis to be supported, this fatigue should be associated with impaired function on neuropsychological tests that measure these functions. In a study of six patients, three with reports of severe fatigue, and three with no complaints of fatigue, Bruno demonstrated that those with severe fatigue showed significant deficits in their performance on measures of attention (double cancellation and trails making tests) and deficits in their ability to process complex information and sustain attention.
Post-mortem histological studies of poliomyelitis victims have demonstrated the presence of poliovirus lesions in areas of the brainstem, including the midbrain reticular formation. Bruno et al. performed MRI scans on 22 post-polio patients and in 8 of the subjects found areas of hyperintense signal in the periventricular and deep white matter, putamen, rostral reticular formation, and centrum semiovale. All of these patients had complaints of severe fatigue. This is significantly different than what was found in aged-matched controls. Seven other patients with severe fatigue had normal MRIs and none of the patients without complaints of fatigue had abnormalities.
Thus, it appears that in some cases subjective complaints of fatigue can be correlated to both poorer function on certain aspects of neuropsychological testing and there may be anatomical correlations with areas of the brain that have been affected by the polio virus. Although preliminary, these findings may have some practical clinical implications. While many of the lifestyle changes discussed later can be helpful to some, there may still be a group of people refractory to these energy conservation techniques. For this group, this hypothesis may be a way to gain a better understanding of their fatigue and in turn may lead to the development of more effective pharmacological treatment.
Many times a few lifestyle adjustments or education regarding energy conservation techniques will reduce this fatigue. These energy conservation techniques include the use of handicap license plates, planning to make as few as trips as possible, balancing activity and rest, sitting instead of standing, moving the location of supplies, and the use of a scooter or similar motorized vehicle when traveling a distance.[96,123,124] The importance of expecting reasonable demands and asking for help when needed is emphasized.
When these techniques do not help, a few medications have been introduced recently to help some of these symptoms. Cashman and Trojan have found success with the anticholinesterase inhibiter Mestinon. In a clinical trial with 17 PPS patients experiencing fatigue using jitter as a measure of electromyographic stability, they measured the response to 10 mg IV edronphonium and found seven patients (41%) had decreased jitter. It was unchanged in eight and increased in two. On the Hare fatigue scale, with a dose of 180 mg mestinon per day, nine patients (53%) noted improvement. Clinical trials using the antiviral agent Amantadine were performed by Stein et al. using a placebo-controlled trial in 25 patients for 6 weeks. These investigators used the visual analog and fatigue severity scale to measure the response. Their findings suggested that amantadine was not significantly better than placebo in controlling fatigue. However, three patients desired to continue the medication, and the investigators suggest that their scales may not be sensitive enough to detect a real change. Although not directly related to the treatment of fatigue, high-dose prednisone was tested to monitor the strength response in a group of 17 PPS patients. Strength was measured on Medical Research Council (MRC) scale and by the Tufts Quantitative Neuromuscular Exam. There were no statistically significant changes, and three subjects withdrew from the study. All of these studies were well controlled, using objective, quantitative measurements. Unfortunately, fatigue is frequently subjective.
Recently, we have had success treating fatigue using low levels of tricyclic antidepressants (TCAs). Whereas these reports are only anecdotal so far, clinical trials will begin soon. The mechanism for this is not clear. Many patients report that they are sleeping better due to the pain relief and possibly the sedative effect of the TCA; however, there is possibly a direct effect on the serotinergic or norepinephrine neurotransmitters. This research demonstrates that pharmacological agents may play a part in the treatment of PPS patients. Further well-controlled studies using objective scales are needed on the use of medications in treating PPS symptoms, especially fatigue.
1. Differential Diagnosis.
Chronic pain is the first or second most prevalent symptom in post-polio patients in most studies.[72,74-77] The differential diagnosis is extensive but should begin with conditions commonly associated with chronic musculoskeletal wear and tear such as osteoarthritis, bursitis, tendinitis, and myofascial pain. In addition, disorders that have significant muscle and/or joint manifestations should be excluded, such as polymyalgia rheumatica, fibromyalgia, polymyositis, and rheumatoid arthritis. Many of the problems that appear to be related to "overuse" of weak muscles, along with abnormal joint and limb biomechanics, may simply represent the inevitable consequences of chronic disability and be no more common in post-polios than they are in individuals with other neuromuscular diseases. In order to facilitate the diagnosis and treatment of pain, we have developed a classification that divides the pain syndromes into three categories.
Type I pain or "post-polio muscle pain" (PPMP) occurs only in muscles affected by polio. It is either a deep or superficial aching pain that many patients say is similar to the muscle pain experienced during their acute illness years earlier. It is characterized by muscle cramps, fasciculations, or a crawling sensation. Typically, it occurs at night or the end of the day when the patient tries to relax. It is exacerbated by physical activity, stress, and cold temperature and is alleviated in part by the use of moist heat and slow stretching.
Type II pain or overuse pain includes injuries to the soft tissue, muscle, tendons, bursa, and ligaments. Common examples are rotator cuff tendinitis, deltoid bursitis, and myofascial pain (especially in muscle of the upper back and shoulders). Myofascial pain in post-polio patients is similar to that in other patients and is characterized by bands of taut muscles and discrete "trigger points" that elicit a "jump" response when palpated. These occur due to poor posture or improper body biomechanics. Fibromyalgia, with its associated symptoms, is another cause of muscle pain.
Type III pain or biomechanical pain presents as degenerative joint disease (DJD), low-back pain, and pain from nerve compression syndromes. Weakness induced by polio muscles as well as poor body mechanics makes the joints, especially in the lower extremities, more susceptible to the development of DJD, as years of ambulating on unstable joints and supporting tissue increases the energy expenditure to perform a given task. These costs accumulate silently over many years until they cross a critical threshold. In a study of 111 post-polio clients, Smith found that 100% demonstrated abnormal gait deviations, 40% demonstrated an uneven pelvic base, and 33% showed major trunk deviations. In addition, the joints of the upper extremity, especially the wrist and shoulders, are prone to DJD when they assume a weight-bearing role, as occurs with the use of assistive devices (canes, crutches, walkers, or wheelchairs) over an extended length of time. The joint pains are only rarely accompanied by swelling and/or inflammation, tenderness, and abnormal range of motion. X-rays of painful, weight-bearing joints may show degenerative changes that are proportional with the amount of stress the joints have sustained; however, even in seriously deformed joints, with the possible exception of the vertebral column, florid degenerative changes are uncommon. Autoimmune syndromes such as rheumatoid arthritis are uncommon; however, the prevalence in post-polio patients is similar to the general population, so if symptoms consistent with these arise, joint arthrocentesis or appropriate laboratory tests should be obtained.
Nerve compression syndromes, including CTS, ulnar mononeuropathy at the wrist or elbow, and cervical or lumbosacral radiculopathy, are syndromes that can cause pain as well as neurological deficits in the post-polio patient.[94,130-132] Risk factors for the development of focal neuropathies of the median and ulnar nerves at the wrist include use of an assistive device such as a cane, crutch, or wheelchair and the length of time that assistive device has been used.[130,132] These neuropathies can be detected on EMG/NCS even before the patient has symptoms characteristic of CTS. In addition to these more common neuropathies, a number of less common ones have been described, including a tibial neuropathy at the ankle (due to compression of a poorly fitting brace), tarsal tunnel syndrome, and brachial plexopathy (associated with the use of axillary crutches). While some of these patients are initially asymptomatic, most go on to develop pain and associated disabilities.
In order to study this further, we retrospectively reviewed the records of 40 consecutive patients seen in our post-polio clinic, gathering information about the type of pain experienced and its location. In this group of 40 patients, 38/40 (95%) had pain complaints. Of the 38, seven (18%) had type I pain, 18 (47%) had type II pain, and 30 (77%) patients had type III pain. The location and type of pain for these patients is shown in Table 10. In another study by Smith and McDermott, the location of pain by method of locomotion for 114 patients was investigated. The results of this study are shown in Table 11.
In general, patients who are ambulators develop degenerative joint disease in the lower extremities, while those who use wheelchairs or assistive devices for ambulation are prone to DJD or overuse syndromes in their upper extremities.
Distribution of Complaints in Upper and Lower Extremities by Type of Pain in Forty Consecutive Post-Polio Patients (Ref. 128)
|a Percents are greater than 100
since some patients have multiple pain complaints.
Prevalence of Chronic Pain by Method of Locomotion in 114 Post-polio Patients (Ref. 95)
|Method of locomotion||Population
|Ambulatory no brace
|Ambulatory with brace
|Ambulatory with crutches
(need personal assistance)
Pain management in post-polio patients is based on a few basic principles, which can be supplemented by class specific recommendations. These basic principles include: (1) improve abnormal body mechanics, (2) correct and minimize postural and gait deviations mechanically, (3) relieve or support weakened muscles and joints, (4) promote lifestyle modifications, and (5) decrease the abnormally high workload of muscles relative to their limited capacity.[71,124] Treatment for type I pain (PPMP) includes periodic rest, stretching, and heat. Stretching may have a role in maintaining the extensibility of muscle and connective tissue; however, it must be performed judiciously, as there are situations in which the patient may derive greater functional benefit and be safer with tighter tendons and reduced joint range of motion. A variety of medications have been used to treat PPMP, but most common ones such as aspirin and other NSAIDS, acetaminophen, and narcotics are of little use. We have had success with the use of muscle relaxants in the benzodiazepam class, such as diazepam or TCAs, especially amitriptyline, a medication used commonly for the treatment of chronic pain.
Treatment for type II pain (overuse pain) includes modification in extremity use, followed by modalities such as ice, heat or ultrasound, TENS, and occasionally NSAID medications. Treatment for myofascial pain consists of myofascial release techniques, including spray and stretch and trigger point injections. Many times rest is not possible because many patients rely on their upper extremities for both locomotion and self-care. In rare cases, steroid injection or surgery may be needed.
Treatment for type III pain (biomechanical pain) includes posture and back care education and decreased weight-bearing or stress through use of assistive devices such as braces, crutches, wheelchairs, and scooters. Abnormal biomechanics can often be modified with fairly simple and practical interventions such as cervical pillows, lumbar rolls, gluteal pads, dorsal-lumbar corsets, and heel lifts. This pain is usually improved by conservative measures aimed at reducing mechanical stress, pacing activities, supporting weakened muscles, stabilizing abnormal joint movements, and improving biomechanics of the body during common daily activities. We use antiinflammatory agents sparingly, and then only in low doses to supplement conservative measures. In particular, efforts should be directed at improving routine activities that occur on a daily basis such as sitting, standing, walking, and sleeping, as well as any repetitious activities at work. Weight bearing with the wrist hyperextended and radially deviated should be avoided.
For patients with carpal tunnel syndrome who must use a cane or crutch, we prescribe an Ortho-ease or "pistol" grip to place the wrist in a more neutral position and increase the weightbearing surface of the palm. Providing adequate support for weakened muscles and unstable joints can often be a difficult challenge; however, the basic orthotic principles are similar to those used in the management of other neuromuscular diseases. For patients with low back pain, lumbosacral corsets, a shoe lift and pelvic lift can help improve biomechanics. For genu recurvatum or genu valgus due to quadriceps weakness or ligamentous instability, a KAFO with a free ankle and an extension stop at the knee is used. Those with dorsiflexor weakness or ankle instability can benefit from an athletic ankle splint, high-top shoes, or an AFO. Many patients need an orthosis that combines strength and lightness. The new plastics and lightweight metals can often be used alone or in combination, but, unfortunately, the most functional solution may not be cosmetically acceptable. Frequently, patients prefer to repair and use their old braces than to start over again with new ones. Others may resist using any kind of brace for cosmetic and psychological reasons. In a study of 104 postpolio patients, Waring et al., prescribed lower extremity orthoses for 36 patients. Orthotics were recommended for the following: (1) improve safety by reducing the risk of falls, (2) reduce pain, (3) decrease fatigue by improving gait speed and symmetry. Subjects who used orthoses reported significant improvements in pain relief, especially at the knee.
Reductions in stress, activity, and weight are lifestyle changes that have the most impact on reducing pain. These strategies may be the most difficult to accomplish, however, because they often require developing behaviors very unlike the old, familiar ways of coping. Essential is altering the pace and intensity of discretionary activities and learning new ways to gain more control over when and how activities are performed. Functional restoration as well as relief of pain is accomplished with the use of an interdisciplinary team, including physical therapists, occupational therapists, psychologists, rehabilitation engineers, and physicians.
D. Cold Intolerance.
1. Differential Diagnosis.
In addition to cold intolerance, patients may also develop color changes ranging from cyanosis to violet color and blanching of the affected extremity, flushing, and hot and cold flashes.[137,138] This can be accompanied by hyperesthesia, burning pain, and decreased manual dexterity. These symptoms may be due to reduced blood flow through areas of atrophic muscle but may also be related to sympathetic intermediolateral column damage to vasoconstrictor neurons at the time of the acute poliovirus infection. This allows passive dilation of cutaneous venous capacitance beds, producing venous congestion and decreased arterial inflow to the skin. Loss of musculature due to atrophy and the dependent position further hinders return of venous blood to the heart, causing edema. Cutaneous venous pooling combined with a decrease in warm blood flowing to subcutaneous tissues causes heat loss and cooling of the extremity. The limb then becomes resistant to warming as the sensitivity of the alpha adrenoceptors increase, accentuating vasoconstriction. Because the extremity is cold, the rate of nerve conduction is slower, although the amplitude of the sensory-evoked potential may be large. Bruno found that polio subjects were more sensitive to electrical stimuli in both affected and apparently unaffected extremities when compared with controls.
At the present time, treatment for cold extremities is largely symptomatic, with the use of multiple layers of clothes, especially in the extremities. Patients report relief with the use of nylon panty hose and woolen long underwear, even in warmer weather.
E. Respiratory Complications
1. Differential Diagnosis.
During the acute phase of polio the most feared complication was impaired respiratory function. The prevalence of patients who developed respiratory compromise requiring the use of an iron lung was estimated to be 15%. Now, 30 to 40 years later, patients with initial respiratory weakness may develop new difficulty with breathing, especially at night or with exertion. Several preliminary studies suggest that as many as 18 to 38% of polio survivors who were successfully weaned off a respirator after acute illness now require ventilatory assistance full or part time.
In a national study of the late effects of polio, Halstead reported that 42% of respondents reported new problems with breathing. Even with improvement in respiratory care, the difference between the prevalence of acute problems (15%) and late effects (42%) suggests either subclinical involvement initially or the combined effects of other cardiopulmonary disease and deconditioning.
More than half of patients interviewed 21 to 30 years after acute polio reported that the respiratory treatment needed had not changed since one year after polio onset, 27% believed impairment had worsened, and 17% felt it had improved; only four needed more daily respiratory support than formerly. The persons at greatest risk for serious late onset pulmonary complications had moderate to severe respiratory involvement initially and usually required ventilatory assistance. The other group at risk are those with severe spine deformities: scoliosis and kyphoscoliosis. While the long-term prognosis for those who were never weaned completely from a ventilator appears favorable, both respiratory problems and dysphagia are potentially life-threatening and should be managed as such.
Pulmonary problems include both obstructive and restrictive lung disease, with symptoms of exertional dyspnea, sleep apnea, and reduced pulmonary endurance. These are due to weakness of respiratory musculature, chronic alveolar hypoventilation, increased scoliosis, decreased pulmonary compliance, and effects of smoking or other diseases, such as asthma.
In a study looking at the prevalence of symptoms suggestive of sleep-disordered breathing, Fischer found that in a group of 155 polio patients, 59% woke frequently, 39% snored, and 41% reported daytime fatigue, significantly different from his 90 controls, where the figures were 8, 8 and 6%, respectively.
The pathophysiology of late-onset pulmonary dysfunction frequently results from complications of chronic alveolar hypoventilation (CAH) and sleep-disordered breathing. CAH is a restrictive disorder caused as a result of inspiratory respiratory muscle weakness, scoliosis, and, often, obesity. There is a loss of vital capacity and ventilatory insufficiency, with subsequent hypercapnia and hypoxia. Patients with expiratory muscle weakness can have difficulty clearing secretions, especially during upper-respiratory infections. This can lead to mucous plugging, ventilation/perfusion imbalance, atelectasis, pneumonia, and pulmonary scarring. Mucous plugs can also cause sudden hypoxia and respiratory failure. Proper evaluation for those with complaints of respiratory difficulties begins with a comprehensive history and physical. This includes remote history of both the need for respiratory support and length of time it was needed, information on the use of tobacco, past medical history regarding pulmonary diseases, including upper respiratory infections, asthma, or chronic obstructive pulmonary disease (COPD). In addition, a review of symptoms should include questions regarding snoring or nighttime awakening, and daytime sleepiness, headaches, muscle weakness, dyspnea, fatigue, changes in body weight, impaired cognition, cyanosis, irritability, anxiety, depression, and decreased cognition, all which are possible characteristics of CAH. On physical examination, the auscultation of lungs in both inspiration and forced expiration should be done, noting any wheezes or evidence of obstructive lung disease. The degree of scoliosis and obesity in the abdomen can help determine the possible lung volume.
A screening PET, including vital capacity (VC), tidal volume (TV), and forced expiratory volume (FEV1) in both a sitting and supine position should be performed as part of the evaluation, as these tests may reveal unsuspected problems only in the supine position. If the initial VC is less than 50% of predicted or less than 1500 ml, more complete testing should be done. This may include repeat PFTs, including a measurement of the maximum volume of air that can be held with a closed glottis. This is a function of pulmonary compliance and the strength of bulbar musculature. For those with evidence of obstructive disease such as COPD, PETs with a bronchodilator can be done. At times it is necessary to obtain an arterial blood gas (ABG) to measure O2, CO2 saturation, and Ph. Sleep-disordered breathing, including central or obstructive apnea, occur in the post-polio population to a greater degree than non-polios. Sleep-disordered breathing can result in hypoxia, right ventricular strain, and, finally, cardiopulmonary failure. When not corrected, insidiously progressive hypercapnia leads to a compensatory metabolic alkalosis. The resulting central nervous system bicarbonate levels can lead to depression of the ventilatory response to the hypercapnia and hypoxia and worsening of the CAH.
When a nocturnal sleep disorder is suspected, overnight oxyhemoglobin saturation monitoring using a pulse or ear oximeter should be performed. In some cases, polysomnography may be needed.[146,147] Transcutaneous CO2 sleep studies can be performed with CO2-sensing electrodes. A CO2 greater than 50 mmHg or %O2 less than 95% for 1 h or more in a patient with a VC less than 50% predicted is diagnostic of CAH. For symptomatic patients with VC greater than 50% predicted, and inconclusive sleep studies, sleep-disordered breathing and inspiratory muscle weakness may be responsible for symptoms.
Both sleep-disordered breathing and CAH can be reversed and symptoms improved with the initiation of ventilatory assistance. Inspiratory positive pressure ventilation (IPPV) can be delivered in many ways. Continuous positive airway pressure (CPAP) or bilevel positive pressure airway pressure (Bi-pap), which independently varies the inspiratory (IPAP) and expiratory (EPAP) pressures, are both suitable alternatives. These can be delivered via an oral, nasal, or oral-nasal ventilator hose.[148,149] Because of the development of newer noninvasive methods of delivering positive pressure, a tracheostomy is seldom needed and should be avoided if at all possible, due to the high rate of complications, including vocal cord paralysis, endobronchial intubation, and laryngeal or tracheal stenosis. Negative pressure body ventilator (NPBVs) such as the iron lung, the Porta-lung, and the chest shell currais are still options for some patients. Drawbacks to these include sleep interference, poor portability, and a high occurrence of apnea, hypoxia, and hypercapnia. Ventilators that work directly on the body are the intermittent abdominal pressure ventilator and the rocking bed. These have some of the difficulties of NPBVs and are generally less effective. Finally, frog breathing or glossopharyngeal breathing (GPB), a method of using tongue and pharyngeal muscles to project a bolus of air past the vocal cords into the lungs can be used. Immediate vocal cord closure traps the bolus in the bronchial system. Bach et al. studied 49 patients trained in GPB. Of those 49 patients who were taught, 26 used it while speaking to keep a more consistent volume and duration despite a mechanical ventilator. Ten used it when changing mechanical breathing aids and 13 did not practice or use the technique. Using this method, people can take up to 200 cc of air per bolus, for up to almost 60 boluses, for a total of up to 3 liters per "breath". Oxygen therapy alone, without maintaining adequate insufflation, can worsen hypoventilation and hypercapnia. This increases pulmonary compliance and, ultimately, respiratory arrest.
Additional considerations include the use of assisted coughing to help clear airway secretions in those who lack sufficient expiratory musculature to do so. Mechanically assisted coughing is more efficient and less labor-intensive, and should be used when manual techniques are not able to generate 5 l/s of peak cough expiratory flow (PCEF). Either manual or mechanical chest percussion can help with atelectasis or mobilization of secretions. All patients with impaired pulmonary function or a history of recurrent respiratory infections should receive influenza vaccines on a regular basis and Pneumovax at least once. Obstructive pulmonary diseases can be treated with combinations of aerosol bronchodilators, theophylline, and periodic corticosteroids.
1. Differential Diagnosis.
To understand some of the psychosocial responses of many post-polio survivors, it is useful to explore the feelings they may have experienced during the initial polio experience. With the onset of paralysis, many individuals believed they were stricken by "the feared disease". They were placed in isolation, and, if paralysis was severe, they came to count on others for basic needs, losing a sense of autonomy, and in many cases their identity. Many polio victims learned to deal with loss of control, pain, and fear by submitting to those in control, complying fully with external expectations and denying personal needs, physical and emotional pain, and even their own individuality. Bruno describes some of the behaviors they were expected to show, including "listen to the doctors, obey the nurses, do not be bad, and be good in school. Some people believe that many of these survivors may have continued to follow these "good rules for behavior" after returning to the community.
Many health-care workers have commented on the existence of a "polio personality". Whether this was a function of social circumstances as described above, the individual's response to the disease, or represented some kind of natural selection also associated with certain behavioral characteristics is unknown. Whereas the behaviors learned in dealing with this illness may have varied from individual to individual, they were behaviors that helped each individual survive -- which is one of the reasons so many polio patients call themselves "survivors". There does appear to be certain coping mechanisms many survivors share. These include independence, patience, perseverance, creativity, industrious behavior, detachment, and denial of limitations. One of the hardest issues most post-polio survivors face is the fact that they are now faced with a second disability. Years after they felt they beat polio, recovering strength and function, they must now deal with recurrence of new symptoms, with the knowledge that the same strategies they used before may be detrimental. Most of all they must deal with the uncertainty regarding the etiology of their symptoms and their prognosis. As a group, polio survivors tend to be competent, hard-driving, time-conscious high achievers who demand high standards of themselves and others and tend to perform at high levels in many areas. For example, it has been reported that they are employed full-time at four times the rate of the general disabled population, they have more years of formal education on average than the general able-bodied population, and they take on marriage and family responsibilities at approximately the same rate as persons who are not disabled. Further, many of these individuals overcame a serious and often life-changing illness. Because they were successful once, these same behaviors tend to emerge later in life in coping with other challenges and illness.
It is believed by some that post-polio survivors frequently exhibit "type A" behavior. In a study done by Bruno and Frick of 676 post-polio subjects, they concluded "type A" behavior was more prevalent than in a nondisabled control population, and the "type A" score was higher in respondents reporting muscle pain and fatigue when compared with subjects without these complaints. They found the polio group exhibited a high rate of symptoms associated with chronic stress, which they felt may have initiated or exacerbated some of the new health problems. To further evaluate psychological traits of post-polio survivors, Conrady et al. tested individuals using a self-report inventory, The Symptom Check List 90-revised (SCL-90R). Peak scores for men in both groups occurred at somatization, depression, anxiety, and phobia. Peak scores for women were at somatization, depression, anxiety, and psychoticism. In general, the tests documented significant psychological distress, especially depression and anxiety (60 to 65%), supporting the hypothesis that devaluation, depression, and isolation may occur with a second disability. However, the researchers are uncertain that the degree of distress experienced can be solely attributed to progressive decline in function, as their data did not show any correlation between psychological distress and physical decrement.
In another study done by Tate et al. using The Brief Symptom inventory (BSI), only 15% had elevated scores for depression. These patients also reported their health was poor or very poor, with more complaints of pain and fatigue. They reported less satisfaction with their employment status and also demonstrated poorer coping strategies than nondepressed polio survivors. Studies of controls (non-polio patients) in the community show a prevalence of depression from 15 to 30%, and those with other disabilities or health problems have BSI scores similar to those with polio. The main differences between these studies is that Conrady recruited subjects from either a clinic population or a post-polio support group, while Tate sent out questionnaires to individuals registered in a statewide polio registry. Therefore, one might conclude that while the post-polio population as a whole demonstrate psychological profiles similar to others in the general population, especially those with health problems, the group of patients who seek out help from either professionals or through peer support groups have higher levels of psychological distress.
Emotional responses to experiencing new medical problems related to polio can be as traumatic and disabling as the physical problems. Although people may experience any combination of denial, anger, frustration, and hopelessness, post-polio patients generally exhibit one of three distinct categories of psychological responses: (1) those who do not regard themselves as handicapped, regardless of the extent of involvement and presence of obvious deformities; (2) those who feel disabled now, but who never did in the past, even during the acute illness; and (3) those who feel that, because they are experiencing polio for the second time, they are "twice cursed".
Polio survivors may resist making lifestyle changes to accommodate weakness, fatigue, and other post-polio symptoms because they have worked so hard to overcome the initial paralysis and achieved a high level of functional performance and personal fulfillment. They may no longer perceive themselves as handicapped and believe, even if some disability remains, that they have conquered polio; the long struggle with polio is over. Instead, new limitations unexpectedly and abruptly developed 25 to 50 years later. However, patients still expect to regain lost function and feel better by persevering and working harder when better advice may be to slow down. Compliance is a large problem with this population. Waring et al. reported that only 41% of patients sporadically used a prescribed brace, while 70% refused to use a recommended crutch or cane because "they didn't want to". In Peachs study on compliance, reasons stated for not following through with recommendations included: (1) refusals to change job or lifestyle; (2) refusal to lose weight; (3) refusal to wear orthotic equipment; and (4) inability to change job or purchase equipment due to financial reasons.
To overcome this combination of denial and a personal history of successful coping, an interdisciplinary approach is helpful. Bruno and colleagues describe an initial evaluation that includes a psychosocial evaluation and psychological studies, with administration of the Reinforcement Motivation Study (RMS) and the Beck Depression Inventory. The treatment of PPS requires a team approach from a psychophysiologic perspective using techniques of multimodal therapy.
The use of a treatment log where patients document physical and emotional symptoms along with activities can help the treatment team design a plan to decrease behaviors that may cause physical symptoms. These include incorporating techniques for time and stress management, energy conservation, and using relaxation techniques. The team can help the patient modify old coping mechanisms that are familiar. For example, have the old brace repaired after the patients first visit rather than prescribing a new one. Beginning with a minor, acceptable intervention may prepare the patient to make necessary major changes later. A patient who has been ambulatory for 35 years may reject buying a wheelchair but agree to use a cane or restrict wheelchair use to the airport. The wheelchair may become more acceptable, however, as the patient learns that the cane is helpful but insufficient to relieve symptoms. Polio survivors may also reject anything that publicly advertises their handicapped status. Changes that enable them to retain some sense of control, such as displaying a handicap placard on the dashboard when desired instead of getting handicapped license plates, may enhance compliance. Getting help through peer support groups may also be a way of coping with new disabilities, as well as being a form through which patients can get state-of-the-art information from professionals who treat patients as well as do research in the area of post-polio. It is also a way they can share advice and practical tips on how to improve independence and deal with the common inconveniences they face on a daily basis. Networking through groups such as the Polio Society and Gazette International Networking Institute (G-I-N-I) is also a way to help meet these needs.
1. Differential Diagnosis.
Difficulty with swallowing has been reported to be a significant complaint in 10 to 15% of all patients with acute poliomyelitis and between 10 to 22% of all patients with PPS. In some cases bulbar involvement may be mild, with complaints of "food sticking"; however, in more severe cases it can lead to aspiration pneumonia and asphyxia. Dysphagia results from bulbar involvement, more specifically in the nuclei of the IX, X and XII cranial nerves. Control of swallowing can be divided into three phases. In the early oral stage food is positioned in the mouth, masticated as needed, and formed into a bolus. The late oral phase involves moving the bolus posteriorly into the region of the anterior faucial pillars, which move medially around the base of the tongue. Phase 2 is the pharyngeal phase, where the swallow response is triggered and the bolus moves through the pharynx. The final stage, the esophageal phase, is when the bolus moves past the crico-pharyngeal membrane, where the epiglottis tilts backward as the vocal cords approximate, preventing aspiration. The bolus then proceeds down the esophagus through peristalsis.
In a recent study by Sonies and Dalakas of 32 post-polio patients, 14 (44%) had symptoms of new swallowing difficulties. Twelve of these patients (38%) had a history of prior bulbar involvement. New swallowing difficulties were noted by nine of the 12 patients with bulbar involvement and five of the remaining 20 with nonbulbar involvement. Detailed evaluation of these 32 patients, including ultrasonography and video fluoroscopy, revealed abnormalities in 31 patients, regardless of whether they were symptomatic or had a history of previous bulbar involvement. Signs of abnormalities frequently included tongue pumping, delayed esophageal motility, pooling in the valleculae, unilateral bolus transport through pharynx, uncontrolled bolus flow into pharynx, difficulty swallowing fluids, delayed pharyngeal constriction, esophageal reflux, and delayed initiation of swallowing reflux. Less common abnormalities included impaired tongue activity, pooling in the cricopharyngeal area, and nasal reflux. Trace aspiration was noted in only two subjects.
In a study of 109 post-polio patients, Coelho evaluated 21 who had complaints of difficulty swallowing. Of those patients, 12 complained that foods got stuck, five had difficulty swallowing pills or dry foods, two complained of frequent choking, and two had complaints of coughing or tightness in the throat. These patients were evaluated using a modified barium swallow (MBS), which used video fluoroscopy to examine swallowing of liquids, paste, and crackers coated with barium. Twenty of these 21 patients had abnormal studies, including decreased pharyngeal transit in 81% of patients and decreased bolus control due to velar and lingual weakness. Twelve patients (57%) had mild involvement, six (29%) had moderate involvement, and two (10%) were severely involved. Only one patient had a normal study. In addition, pulmonary function tests demonstrated abnormalities, including decreased peak expiratory flow (PEF) and maximum expiratory pressure (Pemax) in all but three subjects. Therefore, it was concluded that this combination made the patient at risk for aspiration. In another study of three symptomatic patients, abnormalities on videoflouroscopy included mild to moderate dysfunction in the pharyngeal phase, such as decreased peristalsis, pooling of liquids in the pyriform sinuses, and a delayed swallowing reflex.
Buckholtz found additional abnormalities not necessarily related to a history of polio in 25 patients that he evaluated. These included hiatal hernia in 11, pharyngeal pouches in eight, other neuromuscular disease in four, lateral diverticulum in two, and a Zenkers diverticulum and stricture in one patient. He reports common findings on physical examination may include asymmetric palate or pharynx, dysarthria or hoarseness, limb abnormalities scoliosis, and facial asymmetry.
Finally, in a follow-up study, Sonies reevaluated 11 of her 32 original subjects 3 to 4 years later using similar clinical measures. All patients continued to show mild to moderate findings. Eight had no significant change and three got worse. In addition, one developed pneumonia. These observations suggest a variable progression of symptoms, regardless of patient awareness. It is notable that abnormalities on videoflouroscopy can be seen in both symptomatic and asymptomatic patients, and in both those with and without a history of bulbar involvement, suggesting initial subclinical involvement.
For patients who present with symptoms of dysphagia, evaluation and management includes a thorough neurological exam, with particular attention to the evaluation of the cranial nerves, a screening pulmonary function test, and videoflouroscopy supervised by a speech language pathologist. If abnormalities are noted that place the patient at risk for aspiration, compensatory techniques include: (1) change the consistency of the food or liquid; (2) turn the head to one side; (3) tuck the chin; (4) alternate food and liquid; and (5) avoid eating when fatigued.
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Created: 5th June 2000
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