Spinal Life Australia

Late effects of polio

A guide to management for medical professionals

ON YOUR TRUSTED TEAM FOR LIFEBackground

The World Health Organisation estimates there are 20 million people worldwide currently

living with some degree of disability caused by poliomyelitis (1). Not all polio survivors were

diagnosed with paralytic polio. However, 99% of all polio survivors may have experienced

sub-clinical damage that becomes more evident with age.

The late effects of polio is a neuromuscular condition that can occur in a high percentage

of people with prior exposure to polio. In Australia, it is estimated there are tens of thousands

of polio survivors. International surveys indicate there is up to 80% prevalence of late effects

of polio in polio survivors.

As late polio symptoms progressively worsen, patient coping mechanisms used for many

years may no longer be effective. Over time, partners and carers of polio survivors may

find themselves providing more assistance to the polio survivor. As the progression may

be gradual, the polio survivor and carers may not initially understand or appreciate the

magnitude of the impact of the late effects of polio on their lives.

Impact of polio

In the acute disease, the polio virus attacks the motor neurons resulting in varying degrees

of muscle paralysis and weakness. The brainstem is also involved in the initial infection,

particularly the reticular formation, vestibular nuclei, cerebella nuclei, hypothalamus and

thalamus, and the cranial nerves. Recovery involves the reinnervation of orphaned muscle

fibres by nearby neurons, resulting in enlarged motor units and muscle fibre hypertrophy.

Muscles that appear unaffected can have significant subclinical denervation, the effects

of which usually emerge as the polio survivor ages. Beyond the acute phase there is a period

of stable non-progressive level of disability for several decades.

Impact of the late effects of polio

Pathology: The leading causal hypothesis is that excessive metabolic stress on the remaining

motor neurons, possibly due to long term muscle overuse, results in distal degeneration

of terminal axons and eventually loss of motor neurons. The rate of loss is about twice that

of normal aging. After polio ongoing denervation and reinnervation occurs, but with time the

ability to reinnervate orphaned fibres diminishes. This can occur many years later in muscles

that appear normal but have subclinical denervation.

Treatment: There are no medications currently available to prevent or reverse muscular

atrophy, improve neuromuscular strength or relieve the neuromuscular fatigue of late effects

of polio.

The late effects of polio:

a gradual or sudden onset of progressive and persistent new muscle weakness or

abnormal muscle fatigability (decreased endurance), with or without generalised

fatigue, muscle atrophy, or muscle and joint pain. Sudden onset may follow a period

of inactivity, trauma, or surgery. Less commonly, symptoms attributed to late effects

of polio include new problems with swallowing or breathing.Presentation

Polio survivors may present with new weaknesses, pain, neuromuscular and/or general

fatigue, respiratory difficulties, or sleeplessness. Although affected patients may refer to their

prior episode of polio, many do not willingly disclose past exposure due to past significant

stigma they may have experienced due to polio infection.

As early symptoms of the late effects of polio, such as fatigue, are commonly experienced

by the general population, polio survivors may live with significant and worsening problems

for a considerable time before seeking medical help.

New symptoms may also reawaken the emotional distress experienced during the initial

disease, making discussion difficult for patients. This emotional distress may extend

to traumatic experiences in hospitals and health care facilities, and a general wariness

or mistrust of medical advice.

Diagnosis

The diagnosis of late effects of polio relies nearly entirely on clinical information. There are

no laboratory tests specific for this condition and symptoms vary greatly among individuals.

An extensive work-up including laboratory tests, imaging studies, cerebrospinal fluid

sampling, detailed electrophysiological evaluation, and muscle biopsies may be required

to exclude alternative diagnoses. The diagnostic criteria for Post-Polio Syndrome was first

proposed by Halstead in 1991 (3) and evolved over time to the current March of Dimes

diagnostic criteria (4, 5) which include:

1. Prior paralytic poliomyelitis with evidence of motor neuron loss, as confirmed

by history of the acute paralytic illness, signs of residual weakness and muscle atrophy

on examination, or signs of denervation on EMG.

2. A period of partial or complete functional recovery after acute paralytic poliomyelitis,

followed by an interval (usually 15 years or more) of stable neuromuscular function.

3. Gradual onset (rarely abrupt) progressive and persistent new muscle weakness or

abnormal muscle fatigability (decreased endurance), with or without generalised fatigue,

muscle atrophy, or muscle and joint pain. Onset may at times

follow trauma, surgery, or a period of inactivity. Less

commonly, bulbar dysfunction or respiratory weakness occurs.

4. Symptoms that persist for at least a year.
5. Exclusion of alternative neuromuscular, medical, and orthopaedic problems as causes

of symptoms.

Suggested recommendations for GPs include:

› Including a ‘tick box’ on the new patient registration form for your practice

promoting patients about their polio history

› Conduct an annual health check to review mobility, swallowing and respiratory

problems of polio survivors

› Check current psychological status of polio survivors.Diagnostic considerations:

1. Anaemia
2. Chronic infection
3. Collagen disorders
4. Deconditioning
5. Depression
6. Hypothyroidism
7. Infectious myopathy
8. Myasthenia gravis
9. Deconditioning and weakness

with the ageing process

10. Weight gain

Differential Diagnoses 5

› Amyotrophic Lateral Sclerosis in Physical Medicine and Rehabilitation

› Hypothyroid Myopathy

› Multiple Sclerosis

History Checklist

Polio infection and treatment

(if known)

› Age at onset, severity and progression

› Respiratory impact in acute phase

› Acute management

› Age at best recovery

› Maximum functional recovery

History since polio › Change in functional ability, degree,

speed and nature of change

Present status › Recent changes in activity levels,

employment, environment, nutritional

status, general health and lifestyle

Assessment

Effective assessment requires a full history and review of symptoms, including:

› Early experiences of polio. Explore the physical and psychological impact on their lives.

Identify areas affected in the original polio episode and extent of recovery. Document

any residual long-term effects of initial polio episodes, individuals 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. Late polio

symptoms also tend to occur first in weaker muscles.

› Natural history of presentation. Document and differentiate symptoms of late polio,

including their pattern and progression.Pattern and impact of physical activity

Chronic overuse of affected or unaffected muscles can trigger or exacerbate symptoms.

Health professionals need to make enquiries into activity levels in paid or unpaid work,

sports/fitness training or daily living.

Enquiries need to include any changes to levels or intensity of physical activity.

Fatigue, weakness and pain. Exclude other possible causes of fatigue. The presentation

of fatigue in a polio survivor patient may resemble other conditions and risk potential

misdiagnosis.

Commonly used assessment tools such as manual muscle testing can give a false impression

of strength as one-off movements may be strong. However, polio survivors often show poor

endurance over repeated movements or during sustained activity.

Respiratory insufficiency may develop insidiously, initially at night, in individuals who

appeared previously unaffected, although respiratory disorders are most prevalent in

patients with residual muscle weakness. Symptoms may include unrefreshing sleep, frequent

wakening, waking with headaches, daytime sleepiness, waking gasping or difficulties lying

flat. Obstructive sleep apnoea is also common in polio survivors.

These complications are most prevalent when there is an additional strain on the respiratory

muscles such as respiratory infections, periods of immobility, surgery or obesity. Assessment

for respiratory complications should be considered both for those with night-time symptoms

or daytime effort-related shortness of breath.

Difficulty with swallowing is a potentially serious problem for people living with late effects

of polio. Common symptoms include increased swallowing time and food catching in the

throat. Weakness in pharyngeal constrictor muscles are common in late polio, even in the

absence of symptoms. Patients should also be assessed for risk of aspiration pneumonia.

If swallowing difficulties are suspected, referral to a speech therapist is strongly

recommended. The referral should advise that any tests involving observing muscle action

need to involve several repetitions to assess the impact

of abnormal neuromuscular fatigue.

Cold intolerance is common but underreported

and can affect motor function and comfort.

Walking and postural disturbances.

Difficulty in walking can be due to progressive

weaknesses and joint instability. Walking

problems are more common in people

who have used mobility assistance devices

in the past and have discarded them.

Postural problems can be related

to spinal malformations and weaknesses

in truncal muscles.Recommended management interventions

A multidisciplinary approach:  The ideal approach involves coordinated

multidisciplinary treatment often involving rehabilitation specialist doctors, GPs,

physiotherapists, occupational therapists, orthotists, other medical specialists and allied

health professionals as required (see referral criteria).

Energy management techniques: Successful energy management techniques, best taught

through referral to a specialist physiotherapist or occupational therapist, can help alleviate

the symptoms of neuromuscular and general fatigue and reduce pain. Techniques include:

› Pacing activity  Effective in reducing neuromuscular fatigue and pain and may

improve performance for some.

› Energy conservation  Adapting, simplifying and prioritising daily tasks can

preserve energy and avoid neuromuscular fatigue and pain.

› Aids and appliances  These can help in energy management. Late effects

of polio patients may need encouragement to use aids, which may remind them

of the original polio.

Orthotics:  An orthotics review by an experienced specialist can help reduce overuse

and misuse and reduce energy cost of walking by optimising orthoses and footwear.

Optimised orthotics may help reduce falls.

Respiratory management:  For respiratory insufficiency, confirmed by a respiratory

specialist, due to weak respiratory muscles or scoliosis, respiratory support in the form of

non-invasive ventilation, normally bilevel positive pressure (BiPAP), usually only at night,

is the recommended treatment. Continuous positive airway pressure (CPAP) is used for

obstructive sleep apnoea. If secretion retention is an issue, a respiratory physiotherapist can

advise on positions of treatment and devices such as cough assist that might be useful in the

case of a persistently weak cough.

Exercise and physical activity:  Once good energy management is established, these

can be considered under the guidance of a specialist physiotherapist with experience in

management of neurological conditions, to strengthen muscles where possible and help

improve cardiovascular health.

Caution: safe effective exercise for people with late effects of polio requires an individually

tailored non-fatiguing, pain-free program and careful monitoring to avoid overuse.

Pharmacological management:  As there is no medication proven to reverse the progress

of late effects of polio, pharmaceutical interventions are aimed at alleviating symptoms such

as fatigue, pain and poor sleep. To date, none have been proven to reduce the fatigue and

neurological weakness of late effects of polio. Some medications can alleviate pain and are

used after energy management techniques have been tried.

Psychological therapies:  May be helpful in treating symptoms such as depression

and anxiety. They may also enhance the efficacy of physical interventions by promoting

behaviour change and improving the ability to cope with physical symptoms.

The strength of the evidence is indicated:

 very strong.  strong.  for some.  may help, caution advised!Side effects of some medications can worsen symptoms of late effects of polio including

increased weakness, fatigue, respiratory depression or muscle pain/cramps:

› Anabolic steroids: Steroids are not recommended to improve muscle bulk as the risks

due to side effects greatly outweigh the potential benefits. Metabolic stimulants such

as L-Carnitine and Coenzyme Q10 have been studied and used in some parts of Australia

but have not been proven to be effective.

› Intravenous immunoglobulin: The efficacy and safety of intravenous immunoglobulin

is currently the subject of a multi-centre randomised controlled trial.

› Statins: Many polio survivors have read that some medication classes are bad for

them, including statins. While some statins may lead to muscle fatigue and pain, health

professionals are best placed to provide advice to patients with late effects of polio and

to monitor any potential side effects of statins.

› Anaesthetics: Anaesthetics can cause gastro-oesophageal reflux, tachyarrhythmia and,

sometimes, difficulty maintaining blood pressure.

› Sedatives: Patients with the late effects of polio are nearly always very sensitive to

sedative medications, and emergence can be prolonged. This is probably due to central

neuronal changes, especially in the Reticular Activating System, from the original disease.

› Analgesics: People with late effects of polio may experience breathing problems.

As opioid based analgesics can depress breathing, precaution should be taken when

prescribing them in a patient with the late effects of polio.

› Vaccination: Pneumococcal and influenza vaccinations are recommended.

Nutrition and weight management:  Dietary advice to optimise nutritional status may

also support functional status of the person with the late effects of polio. Weight loss may

help reduce neuromuscular fatigue and pain, taking account of probable low proportion of

lean mass and low mobility. A person being underweight may be due to poor diet, swallowing

issues or difficulty shopping/cooking and may impact late effects of polio symptoms.

Caution: if advising exercise, ensure you recommend a safe and effective program.

Other conditions: Management also needs to include treatment of other conditions which

occur more commonly in polio survivors such as osteoporosis and peripheral neuropathies.

Smoking cessation advice and support may help prevent worsening respiratory function

and vascular complications in a person with the late effects of polio.

Regular monitoring: As the polio survivor with features of the late effects of poliomyelitis

will potentially decline functionally with time, regular annual review helps identify changing

and progressive symptoms and early opportunities to intervene and adapt the individual’s

management program accordingly.

Criteria for referral to secondary care

› Development of new neurological symptoms

› Progression or deterioration of longstanding neurological symptoms

› Uncertainty regarding the diagnosis of late effects of polio

› Advice about symptom management of late effects of polio, especially where respiratory

complications or dysphagia are suspected

› Need for advice on failure of treatment that was previously effective in late effects of polio

› Need for specialist advice on orthotics, biomechanics and orthopaedic problems.1300 774 625

enquiries@spinal.com.au

spinal.com.au

Resources and References

1. Orthotic Management of Polio and Postpolio Syndrome (2019). William Lovegreen,

Michael, Kwasniewski, Preeti Panchang, Marcus J.Smith Atlas of Orthoses and Assistive

Devices (Fifth Edition) 2019, Pages 277-288.e2

2. Front. Neurol., 16 July 2019 Post-polio Syndrome: More Than Just a Lower Motor Neuron

Disease. Stacey Li Hi Shing, Rangariroyashe H. Chipika, Eoin Finegan, Deirdre Murray,

Orla Hardiman and Peter Bede https://doi.org/10.3389/fneur.2019.00773

3. Halstead LS. Assessment and differential diagnosis for post-polio syndrome. Orthopedics.

(1991) 14:1209–17.

4. March of Dimes. Post-polio Syndrome: Identifying Best Practices in Diagnosis and Care.

(2001). Available online at: post-polio.org/edu/pps.html

5. Farbu E. Update on current and emerging treatment options for post-polio syndrome.

Ther. Clin. Risk Manag. (2010) 6:307–13. doi: 10.2147/TCRM.S4440

6. Postpolio Syndrome: emedicine.medscape.com/article/306920-overview. (Updated:

Jun 24, 2019) Author: Divakara Kedlaya, MBBS; Chief Editor: Stephen Kishner, MD, MHA

This Post Polio booklet has been officially

recognised as an Accepted Clinical Resource

by The Royal Australian College of General Practitioners.

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19212.04.2020