Inflammatory demyelinating polyneuropathies Acute Inflammatory Demyelinating Polyradiculoneuropathy (Guillain-Barre Syndrome) Definition - Guillain-Ba

0signs are distal wasting of lower limbs with pes cavus and subsequent foot drop. Later the calf muscles and distal third of the thigh atrophy producing a 'stork leg' or 'inverted champagne bottle' appearance of the leg. Wasting of intrinsic hand muscles occurs and mild distal sensory loss is usual. The condition progresses very slowly over many years TYPES - Two major forms are - CMT type I - is a demyelinating neuropathy, usually autosomal dominant. Patients present with foot deformity in early childhood, which leads to foot drop and weakness in the legs. Sensory loss is relatively mild. Nerve conduction studies reveal severely reduced peripheral n. conduction. CMT type II - is an axonal disease either dominant or recessive Presentation is similar to type I, though there may be more extensive wasting. II. Inflammatory demyelinating polyneuropathies Acute Inflammatory Demyelinating Polyradiculoneuropathy (Guillain-Barre Syndrome) Definition - Guillain-Barre syndrome is an acute, predominantly motor neuropathy, which progresses to its peak in less than 4 weeks. Etiology - Age - usually 20-50 years. Sex - Males predominate. Antecedent infection - usually upper respiratory tract infection or Gl illness in about 70% Infectious agents commonly identified as a precipitating feature are Campylobacter jejuni and cytomegalovirus. Pathogenesis - Probably a cell-mediated immune response to preceding infection. Clinical features - Prodromal stage - Headache, vomiting, slight fever, pain in back and limbs Latent period - Few days to several weeks; may be absent. Stage of paralysis - Patient may come in this stage, the initial stage being absent Alarming clinical picture with motor weakness progressing to paralysis and various sensory disturbances. 1. Motor symptoms - Onset of paralysis sudden or gradual. Headache and fever. All four limbs may be paralysed simultaneously or first lower and then upper. Proximal and distal segment muscles affected equally Involvement of muscles of neck and trunk. Dysphagia and ophthalmoplegia Loss of superficial and deep reflexes. 2. Sensory symptoms - Pain, radicular involving most commonly the proximal portions of the limbs, numbness and 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/kq is exchanged 10 IV immunoqlobulin - may be used as alternative to plasma exchange. Dose