Updated: May 6, 2009
Postpolio Syndrome: Treatment & Medication
Updated: May 6, 2009
Accepted criteria for diagnosis of postpolio syndrome (PPS) are a prior history of poliomyelitis, a stable period after recovery, a residual deficit of the initial polio, new muscle weakness, and sometimes, new muscle atrophy. Fatigue and muscle pain need not be present to meet the criteria for the syndrome.
One possible cause of postpolio syndrome (PPS) is decompensation of a chronic denervation and reinnervation process to the extent that the remaining healthy motor neurons can no longer maintain new sprouts; thus, denervation exceeds reinnervation.1
A second possible mechanism for PPS is motor neuronal loss due to reactivation of a persistent latent virus. In addition to muscle atrophy and denervation, foci of perivascular and interstitial inflammatory cells have been found on 50% of biopsies of patients with PPS. Activated T cells and immunoglobulin M and immunoglobulin G antibodies specific for gangliosides also have been found.
Another possibility is an infection of the polio survivor's motor neurons by an enterovirus that is different from the one responsible for the patient's polio. Others sources hypothesize that PPS is merely the loss of strength due to the usual stresses of aging and weight gain. In patients with PPS, these processes occur in muscles that already are weak, so the consequences are more noticeable compared with those of patients who have not had polio.2
The incidence of postpolio syndrome (PPS) in previous acute polio patients ranges from approximately 22-68%. PPS is estimated to occur in 28.5% of persons who had paralytic polio. The current prevalence is approximately 1.6 million cases. Suggestions have been made that 100% of polio survivors, if tracked for a long period, can develop some symptoms of PPS.
The onset of postpolio syndrome is approximately 30 years after the acute polio.
Symptoms of postpolio syndrome (PPS) usually appear earlier in patients who have very severe residual weakness, individuals who had early bulbar respiratory difficulty in the acute illness, and persons who were older when they contracted acute polio. PPS symptoms tend to occur first in the weaker muscles.
- Fatigue - In individuals without polio or PPS, the functional consequences of aging and loss of motor units may be unnoticeable until a very advanced age. In the individual with PPS, any further loss of strength may be more readily apparent. In contrast to patients with chronic fatigue syndrome, postpolio fatigue is prominent in the early hours of the afternoon and decreases after brief periods of rest. PPS-related fatigue usually does not prevent patients from working.
- Pathogenesis can include chronic pain, type A personality, depression,dysfunctional reticular-activated system, sleep disorders, and respiratory dysfunction.
- PPS produces somnolence and difficulty in concentrating and remembering.
- Pathogenesis may be metabolic exhaustion of the enlarged motor units, neuromuscular junction transmission defects, scarring within the motor neurons, or loss of motor units due to aging.
- PPS produces decreased muscular endurance and increased muscular fatigability.
- A number of functional etiologies for weakness have been hypothesized, including disuse, overuse, and chronic weakness, as well as weight gain.
- Asymmetrical and scattered weakness may be present.
- Some authors have found evidence that previously unaffected muscles later become weak; in these cases, they discovered that the patient was unaware or had not been told that the particular muscle had been affected during the acute episode.
- Muscle pain1,3
- Deep aching pain may be a component of a myofascial pain syndrome or fibromyalgia.
- This feature is extremely prevalent in PPS. Using a retrospective, cross-sectional survey, Stoelb et al investigated the frequency and most common sites of pain in patients with postpolio syndrome.4Pain symptoms were reported by 57 (90.5%) of the 63 study participants; pain was reported most often in the shoulders, legs, hips, and lower back, with the most intense pain occurring in the legs, knees, wrists, head, and lower back.
- Gait disturbance - Difficulty with gait is caused by progressive weakness, pain, osteoarthritis, or joint instability; it is common in patients who previously used assistive devices but later discarded them.
- Respiratory problems
- Respiratory disorders are most prevalent in patients with residual respiratory muscle weakness.
- These changes cause chronic microatelectasis, diminished pulmonary compliance, increased chest wall tightness, chronic alveolar hypoventilation, decreased cough and expiratory flow, and decreased clearing of secretions.
- The new respiratory difficulties are not only related to new respiratory muscle weakness but also to scoliosis, pulmonary emphysema, cardiovascular insufficiency, or poor posture.
- A central component also may occur because acute bulbar polio often affects the medullary structures, including the reticular formation and sleep regulatory system.
- Swallowing problems
- These difficulties can occur in patients with bulbar and nonbulbar postpolio.
- Subclinical asymmetrical weakness in the pharyngeal constrictor muscles is almost always present in all postpolio muscular atrophy patients, including those who do not complain of new swallowing difficulties.
- Autonomic dysfunction - The cause is unclear; the peripheral component could include muscular atrophy and, therefore, diminished heat production.
- Sleep apnea
- This disorder is not uncommon in patients left with residual bulbar dysfunction or severe respiratory compromise.
- Sleep apnea appears to be due to a combination of the following:
- Central apnea, due to a residual dysfunction of the surviving bulbar reticular neurons
- Obstructive apnea, due to pharyngeal weakness and increased musculoskeletal deformities from scoliosis or emphysema
- Postpolio muscular atrophy, resulting in diminished muscle strength of the respiratory, intercostal, and abdominal muscle groups
- Flat-back syndrome
- Another possible symptom in some patients with PPS is the flat-back syndrome, which consists of the inability to stand erect because of forward flexion of the trunk and pain in the low back and legs.
- The flat-back syndrome typically occurs in patients with diminished lumbar lordosis as a result of instrumentation of the spine for scoliosis, vertebral fracture, or degenerative joint disease.
- The trunk extensor musculature plays an essential role in maintaining upright posture, and it may be that PPS-related weakness in this musculature represents a major contributing factor to the flat-back syndrome in these patients.
In persons with postpolio syndrome, progressive weakness and atrophy may be observed in muscles that were affected initially by the poliovirus or in muscles that were spared clinically, which tends to happen in an asymmetrical distribution. Fasciculations sometimes can be observed in atrophic muscles, as a result of the lower motor neuron injury.
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- What is post-polio syndrome?
- What are the symptoms of post-polio syndrome?
- What causes post-polio syndrome?
- How is post-polio syndrome diagnosed?
- How is post-polio syndrome treated?
- What is the role of exercise in the treatment of post-polio syndrome?
- Can post-polio syndrome be prevented?
- What research is being conducted on post-polio syndrome?
- Where can I get more information?
- Find a local Neurologist in your town
What is post-polio syndrome?
Post-polio syndrome (PPS) is a condition that affects polio survivors years after recovery from an initial acute attack of the poliomyelitisvirus. Post-polio syndrome is mainly characterized by new weakening in muscles that were previously affected by the polio infection and in muscles that seemingly were unaffected.
What are the symptoms of post-polio syndrome?
Symptoms include slowly progressive muscle weakness, unaccustomed fatigue(both generalized and muscular), and, at times, muscle atrophy. Pain from joint degeneration and increasing skeletal deformities such as scoliosis are common. Some patients experience only minor symptoms. While less common, others may develop visible muscle atrophy, or wasting.
Post-polio syndrome is rarely life-threatening. However, untreated respiratory muscle weakness can result in underventilation, and weakness in swallowing muscles can result in aspiration pneumonia.
The severity of residual weakness and disability after acute poliomyelitis tends to predict the development of post-polio syndrome. Patients who had minimal symptoms from the original illness will most likely experience only mild post-polio syndrome symptoms. People originally hit hard by the poliovirus and who attained a greater recovery may develop a more severe case of post-polio syndrome with a greater loss of muscle function and more severe fatigue. It should be noted that many polio survivors were too young to remember the severity of their original illness and that accurate memory fades over time.
According to estimates by the National Center for Health Statistics, more than 440,000 polio survivors in the United States may be at risk for post-polio syndrome. Researchers are unable to establish a firm prevalence rate, but they estimate that the condition affects 25 percent to 50 percent of these survivors, or possibly as many as 60 percent, depending on how the disorder is defined and which study is quoted.
Patients diagnosed with post-polio syndrome sometimes are concerned that they are having polio again and are contagious to others. Studies have shown that this does not happen.
Meditation Appears to Cause Changes in Brain's Gray Matter
México a la vanguardia en el Síndrome de Post Polio