Chronic Illness Masquerading as Acute Problem: Post-Polio Syndrome

At a community event, a 72-year-old woman complained to her companions about pain that had developed in her leg, and various clinicians' inability to help her find relief. The conversation eventually turned toward memories from early life. The woman told a story about running in grammar school, indicating she was the fastest among both girls and boys until she developed polio. A clinician who was coincidentally engaged in the conversation made an important link—this woman's polio could be the cause of her pain. He asked if she had mentioned the polio to her physicians. She had not.

Viral polio infections peaked in the 1940s and 1950s, infecting approximately 500,000 people annually around the world. Many people suffered mild symptoms such as headache and malaise, but some developed paralysis quickly. Children were less likely than adults to be paralyzed; 1 in 1000 children experienced paralysis compared with 1 in 75 adults. During the nation's worst outbreak (the 1952 epidemic), the CDC tracked 57,628 cases and 3145 people died. More than 21,000 Americans developed mild to disabling paralysis that year.

The nation has been quick to forget polio and its disabling effects—after all, we have had an effective vaccine since 1955. However, people who were infected with polio as children are now in their 60s and 70s, and researchers have identified a lingering effect of poliovirus infection: post-polio syndrome.

Post-polio syndrome affects polio survivors 30 to 40 years after they've recovered from their initial poliomyelitis. The cause of the syndrome is unknown but seems to be related to degenerating nerve cells. It tends to progress slowly, waxes and wanes, and is potentially disabling. Up to half of people who had polio at a young age may experience post-polio syndrome. People who are at increased risk are those who recovered from more severe polio, with greater loss of muscle function and more severe fatigue. Those who contracted polio as an adolescent or adult are more likely to develop post-polio syndrome. In addition, people who are physically active are at elevated risk.

Common signs and symptoms of post-polio syndrome include the following:

• Progressive muscle and joint weakness and pain
• Fatigue and exhaustion with minimal exertion
• Muscle atrophy
• Breathing or swallowing problems
• Sleep-related breathing disorders, such as sleep apnea
• Decreased ability to tolerate cold temperatures

Diagnosis is based on the presence of 5 factors: prior paralytic poliomyelitis with evidence of motor neuron loss; a period of partial or complete functional recovery after acute paralytic poliomyelitis, followed by an interval of at least 15 years of stable neuromuscular function; slowly progressive, persistent new muscle weakness or decreased endurance, with or without generalized fatigue, muscle atrophy, or muscle and joint pain; symptoms lasting at least a year; and the exclusion of other neuromuscular, medical, and skeletal abnormalities as causes.

Suspect post-polio syndrome when patients meet these diagnostic criteria. Patients may need muscle-strengthening physical or occupational therapy. Advising patients to rest when necessary is important. In addition to prescribing nonsteroidal anti-inflammatory drugs, a trial with lamotrigine may be helpful. Referral to a specialist for workup may be appropriate; if the patient has debilitating post-polio syndrome, he or she can be assessed for intravenous immunoglobulin therapy.