Acute Poliomyelitis Follow-up

Continue physical therapy on an outpatient basis to help muscle reeducation. Specific exercise programs for strengthening lower extremities are helpful to avoid contracture and muscle atrophy. Individuals with bowel and bladder problems need ongoing follow-up as outpatients.

Poliovirus vaccines have been recommended for all pediatric populations in the United States. Vaccination is the most powerful means of prevention, and it has helped to bring about dramatic reduction in the incidence of poliomyelitis. The Western Hemisphere was certified as free of indigenous wild poliovirus in 1994. The recommendation for routine childhood poliovirus vaccination has been changed from an all-OPV schedule to a sequential IPV-OPV vaccination schedule. As of January 1, 2000, the ACIP has recommended exclusive use of IPV for routine childhood polio vaccination in the United States based on the continued occurrence of VAPP, the absence of indigenous disease, and the sharply decreased risk for wild poliovirus importation into the United States (see Medication).

Urinary tract infection usually is transient during acute phase poliomyelitis. Other complications (eg, atelectasis, pneumonia, pulmonary edema, myocarditis) also may occur. Respiratory failure may be the result of respiratory muscle paralysis or airway obstruction from lesions of the cranial nerve nuclei or respiratory center. Related problems caused by central and spinal loss of respiratory drive with mucus plugging or actual pharyngeal weakness may induce direct airway obstruction.

The overall prognosis for patients with poliomyelitis is good. Only 5-10% mortality (slightly higher in pediatric and elderly populations) results from acute paralytic poliomyelitis because of respiratory and cardiovascular impairments. Most patients recover from respiratory failure, and only a small percentage of patients need chronic respirator care. Muscle strength from paralyzed muscles may achieve approximately 60% recovery in the first 3-4 months, probably because of reinnervation of the denervated muscle fibers. Slow recovery may continue for about a year because of hypertrophy of the undamaged muscle.

Postpolio syndrome

Postpolio syndrome (PPS) is a neurologic disorder that is characterized by a new but gradually progressive muscle weakness that develops years after the acute paralytic polio and may be accompanied by pain and fatigue. While the literature has lacked a consensus regarding PPS diagnostic criteria, a set of such criteria, agreed upon and validated by a team of international experts, were published by the March of Dimes Foundation. ^[18] They include the following:

• Previous paralytic poliomyelitis with indication of motor neuron loss, with confirmation derived from a history of the acute paralytic disorder, signs of residual weakness and muscle atrophy demonstrated via neurologic evaluation, and signs of denervation electromyography (EMG)
• A span of time, following acute paralytic poliomyelitis, characterized by partial or complete functional recovery, with a succeeding period, usually lasting at least 15 years, in which neurologic function is stable
• New muscle weakness or decreased muscle endurance, manifesting progressively and persistently and developing either gradually or suddenly; in some cases, this is accompanied by generalized fatigue, muscle atrophy, or muscle or joint pain; an inactive period, trauma, or surgery may be followed by sudden onset; new problems with breathing or swallowing, though less common, are also associated with PPS
• Persistence of symptoms for 1 year or more
• Elimination of neurologic, medical, and orthopedic problems as symptom sources

Slow but gradual progressive weakness occurs decades after the acute attack of poliomyelitis. The weakness could develop in already affected muscles or muscles previously thought to be unaffected. The new symptoms often are accompanied by fasciculations or additional atrophy. Patients also may report fatigue, muscle and joint pain, and intolerance to cold.

PPS is not infectious in origin; rather, it is associated with increasing dysfunction in surviving motor neurons, which has been demonstrated through muscle biopsy showing active denervation and reinnervation. The overall prognosis is good with slow progression of weakness, rarely causing further disability or death.

The etiology of PPS is unclear. A number of possible mechanisms have been suggested to account for the condition. The development of PPS depends on the severity of the acute illness rather than on the age of the patient. Immunologic mechanisms also are suggested, because of the presence of mild inflammatory changes in muscle biopsy. PPS may primarily be caused by a process of attrition and premature neuronal exhaustion. The dysfunction of the muscles results from the loss of motor neurons and reduced neuromuscular reserve capacity, in combination with a disturbed balance between the ongoing reinnervation and denervation, at the expense of reinnervation.

Orthopedic complications result from prolonged, abnormal stresses from skeletal deformity and muscle weakness. These complications include osteoporosis, fractures, instability of joints, osteoarthritis, and scoliosis.

Neurologic complications tend to result from skeletal deformity and the subsequent lifelong use of adaptive equipment. Peripheral nerve entrapments are common with the use of crutches, wheelchairs, and other adaptive devices. ^[19]

In a study of the late effects of poliomyelitis in individuals who had developed the disease in Israel decades ago, Meiner et al found that aging significantly affected their functional independence, with other risk factors for such functional deterioration being non-Jewish ethnicity, the use of a wheelchair, and childhood use of an orthotic device. The investigators suggested that ethnicity may play a role owing to associations with cultural and socioeconomic factors. ^[20]

Key to the treatment of PPS, other than the active involvement of multidisciplinary rehabilitation team members, is energy conservation. Patients should brace their weak muscles, perform only nonfatiguing exercises, simplify their work duties, learn effective time management, take adequate rest breaks, and correlate activity with their symptoms. Modification of their diet and sleep patterns is also essential to improve function.

A prospective, randomized, controlled study from Turkey looked at the effects of home- and hospital-based exercise programs on functional capacity, fatigue, and quality of life in patients with PPS. ^[21] The results indicated that such programs, whether carried out at home or in a hospital, can improve fatigue problems and quality of life in these patients. The study's hospital exercise group also demonstrated improvement in functional capacity.

In a study of 16 polio survivors with weakened calf muscles, Ploeger et al found evidence that dorsiflexion-restricting ankle-foot orthoses (DR-AFOs) can reduce walking difficulties. Using three-dimensional gait analysis to evaluate gait biomechanics, as well as a 6MWT to assess comfortable gait speed and walking energy cost (from ambulant registration of gas exchange), the study compared results between walking with the use of DR-AFOs and walking in shoes only. In addition, questionnaires were used to determine patients’ perceived walking ability. The study indicated that DR-AFO use resulted in better gait biomechanics, gait speed, and perception of walking ability, while reducing walking energy cost. The results also suggested, however, that the efficacy of the orthoses varied according to patients’ shoes-only gait pattern. ^[22]

Nonsurgical treatments for PPS were evaluated in a 2015 Cochrane review by Koopman et al. It was determined that benefit may be derived from intravenous immunoglobulin (IVIG), lamotrigine, muscle-strengthening exercises, and static magnetic fields, but it is currently impossible to draw definite conclusions about their effectiveness. ^[23]

As poliomyelitis became a rare disease following the development of the poliovirus vaccine, postpolio syndrome (PPS) began to attract more attention. Public education on the importance of mass vaccination programs for poliovirus — not only in the United States, but also around the world — is helping to eradicate this debilitating paralytic illness.

Education on PPS, especially among individuals with a history of poliomyelitis, helps patients understand their own disease and contribute to its management. Patients may find additional information regarding PPS from organizations such as Post-Polio Health International, 4207 Lindel Blvd #110, St. Louis, MO 63108-2915 USA, telephone (314) 534-0475. Another organization that may be helpful is WWW.POSTPOLIO.ORG.

For patient education resources, see the Children's Health Center and Brain and Nervous System Center. Also, see Immunization Schedule, Children and Brain Infection.