Post Polio Syndrome (PPS)
Develops 10 to 40 years later following initial acute poliomyelitis onset is with increased fatigue and muscle weakness. The constellation of new symptoms are due to a deterioration of muscles and nerves that have previously coped well with supporting the polio affected limbs. Appears to develop in 20-60% of those who survive the initial polio (actual percent depends on diagnostic criteria).
Two clinical subtypes:
1) Musculoskeletal post-polio syndrome (MPPS) – develop new musculoskeletal symptoms; thought to be due to normal wear and tear process of ageing and the increased demands placed on the musculoskeletal system from the residual effects of the polio
2) Post-polio progressive muscular atrophy (PPMA) – develop new muscular weakness; thought to be due to deterioration of the newer nerve terminals that re-innervated muscle fibres after the initial acute poliomyelitis – considered that the nerve is no longer able to continue meeting the demands of the extra muscle fibre that it innervates as part of the original compensation process for initial damage these collateral sprouts degenerate loss of strength of motor unit (this is most popular theory).
Other hypotheses for aetiology:
death of motor nerves as they can not continue to meet high demands placed on them due to the high number of motor fibre that they innervate
autoimmune destruction of nerve terminals (unknown antibodies have been reported)
reactivation of poliomyelitis virus (very little/no support for this theory)
General fatigue (most common); reduced endurance; pains in joints and muscles; asymmetric progressive muscle weakness and atrophy (especially quadriceps and calf muscles); worsening of joint deformities; progressive respiratory problems (sleep apnoea; difficulty breathing and speaking); intolerance to cold (due to weakness/atrophy of vascular smooth muscles) discolouration of extremities; increased need for sleep. Usually affects muscle that were originally affected – occasionally affects muscle that were spared.
More common in those who had more severe initial polio symptoms and those who had less initial recovery.
Criteria for diagnosis :
prior episode of poliomyelitis with residual motor neuron loss
a period of neurological and functional stability after recovery of acute illness
the gradual or abrupt onset of new weakness or abnormal muscle fatigue, muscle atrophy, or generalised fatigue
exclusion of other conditions
Differential diagnosis – osteoarthritis; fibromyalgia; radiculopathy; motor neuron disease; multiple sclerosis; chronic fatigue syndrome; entrapment neuropathy
Lifestyle modifications – especially to cope with fatigue (eg taking more rest breaks to conserve energy; pacing of activities; motorised scooters)
Need to decrease muscle load (eg braces/splints; weight loss)
Nonfatiguing exercise (eg stretching and gentle progressive strengthening exercises; water exercise) – supported by 8 studies .
Regular assessment/review of foot/leg orthoses.
Speech therapy for dysphagia
Pyridostigmine may be useful for neuromuscular fatigue
One survey of 318 people with polio concluded that “a constant theme in subjects’ responses was the desire to find a health professional who understood their condition…”