Gullian – Barre Syndrome Variant with Unilateral Facial Weakness

It is a postinfectious polyneuropathy due to alteration of protein component of myelin (p2 neurotogenic peptide) leading to demyelination because of autoimmune mechanism. Neurological manifestation begins after 2 to 4 weeks of viral or bacterial infection. Clinical expression includes an acute onset symmetrical ascending weakness (both proximal & distal) with unilateral facial weakness and respiratory weakness and autonomic dysfunction. The diagnosis depends on clinical picture, electrophysiological findings and CSF examination. Immunotherapy is the main stay of treatment. IVIG & Plasmaphrersis done within 2 to 4 weeks of symptoms onset is recommended. Treatment is warranted in non ambulatory patient (Modified Hughes GBS disability scale). The patient who hav not responded to initial IVIG treatment may benefit from second course of IVIG. General supportive care includes cardiorespiratory care, physiotherapy, nutritional management, management of neuropathic pain, bladder–bowel care and prevention of deep vein thrombosis.


Introduction
Gullian -Barre syndrome is also known as acute inflammatory demyelating polyradiculoneuropathy (AIDP), acute motor axonal neuropathy (AMAN weeks.This phase is followed by a relatively static 'plateau phase' ranging from 2 days to 6 months before recovery begins [1].

Diagnosis
The diagnosis of GBS is clinical & is supported by a few

Clinical neurophysiology
Earliest abnormalities is a drop in the amplitude of the evoked muscle action potential & conduction blocks. Marked slowing of nerve conduction can be recorded in about 50% patients. Reduced compound motor unit potential amplitude is the most frequent finding. Absence or prolongation of F wave is common. Proximal blocks can be detected by measuring F wave. Conduction studies improve slowly over a period of several months. Spontaneous fibrillation may detected on electromyography during recovery phase after 2 or 3 weeks [1].

Pathogenesis
AIDP is multifocal noninfective inflammatory process causing demyelinaton or axonal degeneration of peripheral nerves. ADIP is generally due to T cell mediated immune myelin damage. Increased incidence of several axonal degeneration in GBS following C. jejuni infection is known with more severe involvement. The mechanism of axonal damage is different molecular mimicry due to shared epitopes with gangliosides [1] (Figure 1).

Prognosis
Recovery is common & often complete in the majority.Mortality is now ≤ 5%. Most of the death in childhood are due to preventable respiratory complication. Acute axonal neuropathy, with good pgognosis.Acute axonal and sensory axonal neuropathy generally causes poor prognosis. Miller Fisher variant in which cerebellar signs, cranial nerves are involved also has a poor prognosis. The disabilities included foot drop, pes cavus and postural tremor & persisting weakness of the hands [1].

Treatment
Supportive symptomatic treatment is the mainstay of therapy in the majority. The child should be closely observed in hospital, objective assessment of respiratory function, regular measurement of vital capacity is performed. Ventilatory support should be considered if there is evidence of respiratory insuffiency [3,4].
• Chest and limb physiotherapy should be initiated early and carried out carefully. Bladder and bowel function should be attended to.

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Plasmapheresis has been shown to be effective in decreasing severity and shortening the non ambulatory phase. No significant complication ensue fron well conducted plasmapheresis. Several paediatric studies support the results.

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Intravenous immunoglobulin (IVIg) is atleast as effective as Plasma exchange. IVIg is now become the preferred treatment due to ease of administration. Dose of IVIg 0.4 g/ kg body weight daily given on five successive days or two successive doses of 1 g/kg may be given active treatment of impending/ respiratory failure is imperative. Indication of immunotherapy includes a hughes GBS disabilities scale ≥3 or when patient is unable to walk unaided for 10 meters [5][6][7].

Conclusion
Acute flaccid paralysis in children is a medical emergency. AFP is a clinical syndrome with array of differential diagnosis.The common causes of AFP are Gullian -Barre syndrome, Anterior horn cell myelitis and Acute transverse myelitis. Rapid evolution of the weakness can lead to respiratory failure. Hence a child with AEP Should be managed in PICU in the initial few days. Immunotherapy is a main stay treatment.