tingling of limbs. All forms of sensations may be impaired at the periphery, and muscles may be tender

tingling of limbs. All forms of sensations may be impaired at the periphery, and muscles may be tender. 3. Cranial nerve paralysis - Facial and bulbar paralysis common, and weakness of extraocular muscles may also occur. 4. Reflexes - usually depressed or absent. 5. Sphincters - rarely involved, retention of urine may occur. 6. Symptoms of toxemia - Fever, rash, slight cardiac dilatation, albuminuria, leucocytosis. CSF - Typically elevation of protein with normal cell count, in some cases no increase of protein and cell count more than 30 cells mm3 Nerve conduction studies - Typical early findings are prolonged distal motor latencies in either upper or lower limbs, prolonged F wave latencies and small m action potential amplitudes. Slowing of n conduction indicating demyelination is seen late. DIAGNOSTIC CRITERIA (Asburys) - A. Features required for diagnosis. 1. Progressive motor weakness of more than one limb (can progress to total paralysis of all four extremities) 2. Areflexia. B. Features strongly supporting the diagnosis. (a) Clinical features 1. Progression of symptoms and signs over days upto 4 weeks 2. Relative symmetry of symptoms. 3. Mild sensory symptoms or signs. 4. Cranial nerve involvement, especially facial diplegia. 5. Recovery beginning 2-4 weeks after progression ceases. 6. Autonomic dysfunction. 7. Absence of fever at onset of illness. (b) CSF picture 1. Elevated CSF protein after one week of symptoms. 2. Cell counts of 10 mononuclear leucocytes per cmm of CSF. (c) Electrodiagnostic studies. Evidence of nerve conduction slowing or block C. Features making the diagnosis doubtful. 1. Marked persistent asymmetry of weakness. 2. Marked bladder or bowel dysfunction at onset or its persistence thereon. 3. Presence of polymorphonuclear leucocytes or >50 mononuclear leucocytes per cmm of CSF 4. Sharp sensory level D. Features excluding the diagnosis. 1. Diagnosis of acute intermittent porphyria or recent diphtheria infection. 2. Diagnosis of botulism, poliomyelitis, hysterical paralysis, toxic neuropathy. 3. Purely sensory syndrome COURSE - Within a period of 3 weeks, it progresses to maximum disability, often with complete quadriparesis and respiratory paralysis. Recovery without significant disability occurs in about 80%, subsequent relapses occur in about 5% of patients. Management - No specific therapy known 1. ITU - as long as any weakness of trunk muscles persists. Vital capacity should be measured every 2-4 hours in early stages. 2. Analgesics - Aspirin or paracetamol. 3. Hot packs - as in treatment of poliomyelitis may be useful. 4. Corticosteroids -for patients with bulbar symptoms or severe generalised weakness. 5. Antibiotics-to prevent secondary infection. 6. Supportive treatment -IV or intragastric feeding may be necessary 7. Physiotherapy - Early active and passive movements. Splints to prevent foot and wrist drop. 8. Assisted respiration - if respiratory or bulbar paralysis. 9. Plasma exchange - Indications - inability to walk unaided, rapid and significant reduction in serial vital capacity measurements and onset of bulbar paralysis Usually 4 to 5 sessions of PE are carried out over 14 days, at each of which about 50 ml/kg is exchanged. 10 IV immunoglobulin - may be used as alternative to plasma exchange. Dose 0. 4g/kg/day for 5 days. Effective in reducing the disability in the disease. 11. Combination therapy - In contrast to PE, IV Ig therapy has the advantage of other medications being given simultaneously (In PE co-medications are removed jointly with the exchange). Hence IVIg therapy has been combined with high dose IV methylprednisolone (500 mg daily for 5 days). 12 Liquorpheresis (CSF filtration) - is a technique to purify CSF from pathological factors (probably responsible for manifestations of GBS) It has been postulated that pathological cellular or humoral factors are concentrated in the CSF and these block sodium channels and hence liquorpheresis is attempted as a direct therapeutic intervention Miller-Fisher syndrome - is characterised by ophthalmoplegia, ataxia and areflexia without weakness It is considered to be a variant of GB syndrome. Antibodies to ganglioside GQ1b are seen in 90% of patients. Chronic inflammatory demyelinating polyneuropathy (CIDP) - is a subacute or chronic progressive demyelinating neuropathy. Progression over 2 months distinguishes it from G-B syndrome. The disorder is associated with increased frequency of HLA DR3, indicating that the disease may result from an aberrant immune response leading to a chronic form of G-B syndrome. III Vasculitic neuropathies - in systemic disorders such as RA and PAN which produce a number o€ different lesions within the nerve and are hence termed multifocal Because of the multifocal onset, the combination of individual peripheral n. involvement is called 'mononeuritis multiplex'. Diagnosis - High ESR or positive antinuclear factor or antinuclear cytoplasmic antibody. Nerve biopsy reveals patchy multifocal process. IV. Multifocal motor neuropathy - resembles CIDP, but does not respond well to steroids. It has considerable similarities to LMN form of MND, especially because of marked fasciculations. Disorder is suspected in patients that present with asymmetrical upper limb wasting in absence of sensory disturbance Diagnosis - Evidence of conduction block often between supraclavicular fossa and axilla. (c)