Poliomyelitis and Post Polio Syndrome

Mazloumi MD

Qaem,s Hospital

What is Poliomyelitis?

• polio= gray matter

• Myelitis= inflammation of the spinal cord

• This disease result in the destruction of motor neurons caused by the poliovirus.

• Polio is causes by a virus that attacks the nerve cells of the brain & spinal cord although not all infections result in sever injuries and paralysis.

POLIOMYELITIS

• “Picornavirus”• 3 types: Poliovirus 1,2,3• Ingested, spread by

faeco-oral route: Commoner in areas of poor sanitation

• Infants protected by maternal antibodies

History

• Associated with man since ancient times

• Egyptian hieroglyph indicates presence since 1400 BC

• 1840 - Heinle characterizes poliomyelitis

• Poliomyelitis – “grey marrow” in Greek

• 1954 - Salk vaccine• 1960 - Sabin vaccine• 1991 – Molla produces polio in

vitro from virus RNA• 2002 – completele synthetic

production

Polio Eradication:Status in 1988

Polio Eradication: Status in 1998

Epidemiology

• “Silent circulation” Many hundreds may be infected prior to the development of a single case of paralysis

• WHO considers a single confirmed case of polio in an area of low occurrence an epidemic

How is polio transmitted?

• Poliovirus is transmitted through both oral and fical routes with implantation and replication occurring in either the orapgaryngeal and or in the intestine of mucosa. Polio cases are most infected for 7-10 days before and after clinical symptoms begin.

The unique stages of infection and pathogenesis of poliomyelitis.

Poliovirus, an “Enterovirus” has an icosahedral capsid shell that protects it from digestion.

GI Tract Blood Cord CNS Paralysis of motor neurons

Provocative Poliomyelitis

• Provocative poliomyelitis occurs when a person having polio virus circulating in blood (viraemia) receives any intra-muscular injection.

• Reason is increased susceptibility of the relevant anterior horn cells resulting in settling of the circulating polio virus there and consequential paralysis.

What are the symptoms?

• Many include fever, pharyngitis, headache, anorexia, nausea, and vomiting. Illness may progress to aseptic meningitis and menigoencephalitis in 1% to 4% of patients. These patients develop a higher fever, myalia and sever headache with stiffness of the neck and back.

Clinical Pattern of Polio

Virus travels through blood and the nerves

… And each place in the cord that nerve cells are destroyed causes paralysis of that part of the body controlled by those motor neurons.

POLIO ATTACKS MOTOR NEURONES

Poliomyelitis:Clinical Features

• In 1% of cases virus invades CNS:

• Multiples and destroys anterior horn cells.

• In severe cases, poliovirus may attacks motor neurones in brainstem, leading to difficulty in swallowing, speaking and breathing

Equanous deformity

• Tibialis anterior muscle paralysis (most common)

• Heel elevated• Toe gait• Achill tendon

contracture

Calcaneous deformity

• Gastrosoleous muscle paralysis

(Cavous foot)

Varous deformity

• Peroneal muscle paralysis ,associate with equanuse deformity

(paralytic equano varous )

Planovalgus deformity

• Tibialis posterior paralysis

( Flat foot )

Paralytic Scoliosis

• Paravertebral muscleparalysis

( Pelvic title )

Knee deformities

• Hamstring muscle paralysis(Geno recurvatum )

• Quadriceps muscle paralysis ( knee flection contracture )

Treatment

• Intensive physiotherapy

Treatment

Orthosis

treatment

Inactivated Vaccine

• Immunity to Poliovirus 1,2,3

• Safe, effective

• Injection

• No gastrointestinal immunity: Risks of continued circulation of virus in endemic areas

• Expensive

Jonas Salk

Live Vaccine

– Live attenuated oral vaccine (Sabin, 1961):– Risks of viral mutation, leading to potential regain

of virulence: – Excretion of live virus thru’ faeces

– Live vaccine cheaper, and suitable for mass vaccination programmes

Poliomyelitis:Current Status

• Eradicated from developed world in 1960s

• Remains endemic in 7 countries

• Eradication plan by WHO by year 2000: not yet achieved, but progress is being made