Diagnosis and Medical Management of Post-Polio Syndrome

Dr Michael Watt Consultant Neurologist RVH, Belfast

How easy it is to Forget

 What is PPS?

 Have I got it or have I got something else?

 What can I do about it?

History of PPS

 First case described in 1875 (Raymond, 1875)  Zilkha (1962) described 11 cases occurring 17-43 years post acute illness.

 Halstead (1985) – “post polio syndrome”, (PPS), then, re defined it in 1991.

 Dalakas (1995) defined post polio muscular atrophy (PPMA)  Berg(1996) “Post Polio Muscular dysfunction” (PPMD)  Howard (1988,2003)) Post-polio functional deterioration (PPFD)

Halstead’s 1985 Definition

     Confirmed history of polio Partial or fairly complete neurological and functional recovery after the acute episode.

Period of at least 15 years with neurological and functional stability Two or more of the following health problems occurring after the stable period:  Extensive fatigue      Muscle and or joint pain New weakness in muscles previously affected or unaffected New muscle atrophy Functional loss Cold intolerance No other medical explanation found

Prospective study of New symptoms

NEW DIFFICULTIES EXPERIENCED BY SUBJECTS WITH PRIOR PARALYTIC POLIO *

Patients

Symptom Fatigue alone Pain alone Pain and fatigue Weakness alone No.

2 7 § 1 4 Requiring New Aids 1 0 1 0 Changing Activities 0 1 0 0 Weakness and pain Weakness and fatigue Weakness, pain and fatigue No new symptoms 9 2 7 18 2 1 2 0 0 0 1 0 *

Types of complaints reported by 32 of the 50 subjects with paralytic polio. Twenty-two complained of some new weakness. In seven subjects, the new symptoms necessitated the use of new aids to daily living and in two different cases, the symptoms had led to lifestyle changes.

§

All seven complained of nonradiating lumbar or cervical pain.

Windebank AJ et al. Late effects of paralytic poliomyelitis in Omsted County, Minnesota. Neurology. 1991; 41:507-507

MOST COMMON NEW HEALTH AND FUNCTIONAL PROBLEMS OF PATIENTS WITH CONFIRMED POLIO EVALUATED IN TWO POST-POLIO CLINICS Texas * (N = 132) Wisconsin § (N = 79) N % N % HEALTH PROBLEMS Fatigue Muscle pain Joint pain Weakness: 117 93 93 89 71 71 68 68 61 86 86 77 91 69 63 80 Affected muscles Unaffected muscles Atrophy FUNCTIONAL PROBLEMS Walking Climbing stairs Dressing 66 37 84 80 23 50 28 64 61 17 42 31 - 53 13 53 39 - 67 16

Epidemiology of PPS

 The frequency of PPS ranges between 15% 80%, depending which population are studied, and which criteria are applied.  In European populations a prevalence of between 46% (Holland) and 60% (Edinburgh, Norway, Denmark) is seen in the literature.

What Causes PPS?

Motor Neuron Loss?

CNS CNS Normal: One nerve/motor muscle unit PPS: multiple motor units /nerve

Pathophysiology

Theories:   

Remaining healthy motor neurons can no longer maintain new sprouts Decompensation / chronic denervation and reinervation process.

Denervation exceeds reinervation

Theories (contd.)



Motor neuronal loss due to reactivation of a persistent latent virus.



Infection of the polio survivor’s motor neuron by a different enterovirus



Loss of strength associated with aging, in already weakened muscles

Possible Causes of Late Complications of Polio

What Causes PPS?

     Accelerated natural ageing Falling nerve to muscle motor unit ratio Inflammation and active immune response Co-morbidity:     Orthopaedic problems Radiculopathy and entrapment neuropathy Respiratory failure General medical problems PPS is more likely with  increasing age;   the more severe the initial weakness was The more time that elapses after the attack of polio

Non-paralytic polio and PPS?

   For non-paralytic polio it is impossible to exclude a scaled down version of the same processes.

Such a diagnosis however is presumptive and cannot be categorically confirmed.

When we have further knowledge about the specificity and sensitivity of EMG, muscle biopsy and immunological tests it should be possible to give more definite diagnoses

Main Clinical Features of PPS

    Fatigue (Commonest) Weakness Muscle pain Gait disturbance     Respiratory problems Swallowing problems Cold intolerance Sleep apnoea

Fatigue

        Prominent in the early hours of the afternoon Decreases with rest Pathogenesis:Chronic pain / Muscle pain Sleep disorders/ respiratory dysfunction Difficulty in remembering/ concentrating Decreased muscular endurance / Increased muscular fatigability “Polio wall” Generalized or muscular

Weakness

 Disuse  Overuse  Inappropriate use  Chronic weakness   Weight gain Joint problems

Muscle Pain

 Extremely prevalent in PPS  Deep aching pain  Myofascial pain syndrome / Fibromyalgia  Small number of patients have muscle tenderness on palpation

Swallowing Problems

 Can occur in bulbar and non bulbar polio  Subclinical asymmetrical weakness in the pharyngeal constrictor muscles : almost always present in PPMA (Post polio muscular atrophy)  Not all are symptomatic

Cold Intolerance

Autonomic nervous system dysfunction?

May relate to sympathetic intermediolateral column damage during acute poliomyelitis Peripheral component may include muscular atrophy leading to reduced heat production

Sleep Apnoea

    Combination of the following: Central: residual dysfunction of surviving bulbar reticular neurons Obstructive: pharyngeal weakness and increased musculoskeletal deformities from scoliosis or emphysema PPMA, diminished muscle strength of respiratory,intercostal & abdominal muscle groups

Risk Factors for Sleep Apnoea

 Age of onset (More severe disease in adolescents and adults)  Severity of original paralysis  Managed with BiPAP

Is it PPS?

 Other neuromuscular diseases  Nerve entrapment

Is it PPS?

 Spinal cord and nerve root problems  Scoliosis

Is it PPS? – Other things to think of

     Other rheumatological disorders: rheumatoid arthritis, lupus, Sjorgren’s syndrome or just osteoarthritis Endocrine disorders: hypothyroidism, adrenal failure, rarely pituitary failure Orthopaedic problems: shoulder rotator cuff tears and impingement syndrome, spondylosis, bursitis, metatarsalgia.

Breathing disorders: restrictive problems with scoliosis, obstructive sleep apnoea General medical problems: heart failure, diabetes

How is it Investigated?

 MRI scans  Blood tests  EMG and nerve conduction studies  X-rays  Overnight oximetry  Sleep studies  Pulmonary function tests

What can be done about PPS?

 Firstly, drugs don’t work, at least not the one’s we have at the moment.  Modafanil and pyridostigmine, steroids and ivIg are all proven not to have any benefit.

What can be Done for PPS?

Treat Co-Morbidities

     If you rely on your shoulders,  protect them and seek early advice for shoulder symptoms. e.g.. “Save Our Shoulders”   Insist on proper evaluation of the shoulder e.g. USS or MRI Ensure the surgeon has experience of PPS.

Treat general medical and endocrine problems.

Treat carpal tunnel syndrome Look at posture to prevent progressive deformities e.g.. Profiling bed, trunk support when sitting.

Make every effort to treat and avoid rising BMI: diet, Orlistat, Sibutramine.

Treat Co-morbidities  Get orthoses to off load and support joints that are failing  Use lightweight modern materials for orthoses e.g. carbon fibre, titanium

Treat Co-Morbidities Use strategies to avoid over stressing systems that are already challenged e.g. powered wheel chair, PAPAW.

Treat Co-Morbidities Night time hypoventilation can be easily treated with NIPPV

Active Management of PPS 

Start an exercise program:

  Aerobic, i.e.. Within the limits of the muscles’ glucose and oxygen supplies. In practice this means 2-3 minutes exercise, 1-3 minutes rest. Within your limit (Avoid “boom and bust”). Do not exercise until it hurts the muscles. If your muscles ache and are stiff the next day you over did it.

 Use pacing and graded exercise goals: small increments in your limit are achievable e.g.. 5-10% every 1-2 weeks.

Exercise for PPS  Where possible try and use water based activities: you are 30% lighter in the water and will off load joints that might be struggling with gravity based exercises.

 Be consistent.

 Exercise reverses DECONDITIONING

Active Management of PPS

   Get good pain control: non-steroidal anti inflammatory drugs, medium grade opiates e.g.. codeine, but use non-pharmacological means e.g.. Counter stimulation TENS, rubifacients Keep warm, where possible, spend time in a warm climate (Nordby 2007) Keep respiratory difficulties under review and take advice about the need for night time ventilation support, stop smoking, and ask for advice about respiratory muscle training

Active Management of PPS  Make environmental adaptations and use assistive technology: e.g.. Door entry systems, remote switches, environmental control systems, level access bathroom facilities  Join a group or start one.

Conclusion  People with PPS get more out of their muscles and joints than would have been expected.  They seem to remain independent in the long term to a degree that is contrary to expectations.  The symptoms are manageable and with proper measures quality of life can remain good.