poliomyelitis and post polio syndrome final.pdf · 2015. 2. 14. · poliomyelitis and post polio...

Poliomyelitis and Post Polio

Syndrome

S.M. Mazloumi MD

Associate professor

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

tenotomy osteotomy Tendon transfer

arthrodesis Soft tisue

release

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