4. Etiology
Post infectious autoimmune peripheral neuropathy
Mainly motor but sometimes sensory and autonomic
nerves
Most patients have a Demyelinating neuropathy
Often occurs after a respiratory or gastrointestinal infection
by about 10 days.
Infection with Campylobacter jejuni is associated with a
severe form of the illness.
Following vaccines against Rabies, Influenza,
Poliomyelitis (oral)and
Possibly Conjugated Meningococcal vaccine.
5.
6. Clinical Manifestations
Areflexia, flaccidity, and ascending symmetric weakness
Tenderness on palpation and pain (initial)
Deep tendon reflexes are absent even when strength is
relatively preserved.
Sensory signs are usually minor compared with the
dramatic weakness
Bulbar involvement occurs in about half of cases
Dysphagia and facial weakness are often impending signs
of respiratory failure
Gag is very Important
7. Clinical Man…
Dysfunction of autonomic nerves can lead to:
BP Changes, Tachycardia, and other arrhythmias
Urinary or stool incontinance or retention; or episodes of
abnormal sweating, flushing, or peripheral
vasoconstriction
Preservation of bowel and bladder function, loss of arm
reflexes, absence of a sensory level, and lack of spinal
tenderness would point more toward Guillain-Barré
syndrome
8. o Miller Fisher variant:
Ataxia,Ophthalmoplegia,Areflexia
o Chronic relapsing polyradiculoneuropathy
Recur intermittently or do not improve for a period of
months or years
o Congenital Guillain-Barre syndrom
o Rare Generalized hypotonia, weakness, and areflexia in
an affected neonate in the absence of maternal
neuromuscular disease.
Prognosis &Outcome
75% Cure (1-12 mo)
20% mild Sequels
5% Mortality
7% acute recurrence
10. Laboratory and Diagnostic Studies
o Albuminocytologic Dissociation (2nd week)
o NCV and EMG also may be normal early in the disease
o Electromyography shows evidence of acute denervation of
muscle
o (CK) level may be mildly elevated or normal
11. Treatment
Moderate or severe weakness or rapidly progressive
weakness should be cared for in a pediatric ICU.
Endotracheal intubation should be performed electively
in patients who exhibit early signs of hypoventilation
accumulation of bronchial secretions, or obtunded
pharyngeal or laryngeal reflexes.
IV immunoglobulin is beneficial in rapidly progressive
disease.
Plasmapheresis, and/or immunosuppressive drugs are
alternatives, if IVIG is ineffective.
Steroids are not effective
12. Prognosis &Outcome
75% Cure (1-12 mo)
20% mild Sequels
5% Mortality
7% acute recurrence
Direction of cure GagExtremitiesDTRs
Poor outcome
• Cranial nerve involvement
• Intubation, and
• Maximum disability at the time of presentation
Conduction block is predictive of good outcome
14. Etiology & Epidemiology
Autoimmune (complement-mediated )
antibodies to the acetylcholine receptors at
the neuromuscular junction
15. Clinical Manifestations
o Classic myasthenia gravis may begin in the teenage
years
o onset of ptosis, diplopia, ophthalmoplegia, and
weakness of extremities, neck, face, and jaw
o Gradually worsen as the day progresses or with
exercise
Two Subtypes
o Ophthalmic Myasthenia
o Systemic Myasthenia
16. Diagnostic Studies
1. IV edrophonium chloride (Tensilon) transiently
improves strength and decreases fatigability.
2. Antiacetylcholine receptor antibodies often can
be detected in the serum.
3. Repetitive nerve stimulation shows a
decremental response at 1 to 3 Hz.
17.
18. Treatment
Acetylcholine esterase inhibitors (pyridostigmine [Mestinon])
Thymectomy
Prednisone
Plasmapheresis
Immunosuppressive agents.
When respiration is compromised, immediate intubation and
admission to an ICU
19. Neonatal Transitory Myasthenia
Gravis
o 10-20% of myasthenic mothers
o Symptoms persist for 1 to 10 weeks (mean 3 weeks)
Almost all infants born to mothers with myasthenia have
antiacetylcholine receptor antibody, but neither antibody titer nor
extent of disease in the mother predicts which neonates have clinical
disease.
o Diagnosis is made by showing clinical improvement
lasting approximately 45 minutes after IM administration
of neostigmine methyl-sulfate, 0.04 mg/kg.
o Treatment with oral pyridostigmine or neostigmine 30
minutes before feeding is continued until spontaneous
resolution occurs.
20. Congenital myasthenia
Its not an immune mediated.
Manifest as hypotonic infants with feeding
disorders and variable degrees of weakness
It has Three types:
Presynaptic (familial infantile myasthenia)
Synaptic (congenital end plate acetylcholinesterase deficiency)
Post Synaptic(slow channel myasthenic syndrome)
