Dr Massud Wasel MD DO ND BSc(Hons) P.G.C.A.P Neurology Dr Massud Wasel MD DO ND BSc(Hons) P.G.C.A.P
NEUROPATHY A pathological process affecting peripheral nerve system Pathology: Demyelination Axonal degeneration Compression Infarction infiltration
Mononeuropathies Caused by peripheral nerve compression Carpal nerve syndrome Idiopathic Hypothyroidism DM Pregnancy RA Obesity Acromegaly
Clinical features Tingling in fingers(esp. at night) Weakness of thenar muscles Wasting of thenar muscles Weakness of abductor pollicis brevis (raising thumb away from palm) Weakness of opposition of thumb and little finger Tinel’s sign(tapping over carpal tunnel) Sensory loss of palm
management Splint wrist Surgical decompression OMT
Ulnar nerve compression Usually occurs after trauma of elbow Clinic: Wasting and weakness of interossei and hypothenar muscles Sensory loss inn the ulnar distribution
Radial nerve compression Saturday night palsy Clinic: Wrist drop Weakness of finger extension
Mononeuritis multiplex (multiple mononeuritis) Aetiology : DM Leprosy Vasculitis Sarcoidosis Malignancy Neurofibromatosis HIV infection
Polyneuropathies Guillain-Barre syndrome: Acute inflammatory post-infective polyneuropathy Follows 1-3 weeks after infection(often trivial,or compylobacter infection) Clinic: Weakness of distal limb muscles+- numbness Weakness ascends over days for up to 3 weeks Can affect repiratory & facial muscles in 30%
Investigations: Diagnosis is made on clinical grounds Nerve conduction studies CSF(cell count normal,protein raised 1-3g/l)
Management: Measurment of respiratory function(art. Blood gases,vital capacity,FEV1) Assisted ventilation if necessary) I.V gama-globulin Plasmapheresis Heparin for prevention of thromboembolism Prognosis:spontaneous gradual recovery
Other polyneuropathies Metabolic: DM,uraemia, Toxic:alcohol,drugs(phenytoin,isoniazid,metronidazole) Vitamin deficiencies thiamin (B1),pyridoxine(B6), B12, nicotinic acid
Vitamin B12 deficiency (sub acute combined degeneration of the cord) Aetiology: Low dietary intake(vegan diet) Impaired absorption (lack of intrinsic factor): pernicious anaemia, gastrectomy, congenital lack of intrisic factor Impaired absorption (small bowel): pancreatic insufficiency, terminal ileal disease, bacterial overgrowth-bacterial utilization of B12 Abnormal metabolism:transcobalamin II deficiency-congenital lack of B12 transporter
Clinic: Distal sensory loss(light touch,vibration, joint position sense) Absent ankle jerk Optic atrophy Dementia
Investigations: Reduced serum B12 Macrocytosis Megaloblastic bone marrow Management:Parenteral B12
Peroneal muscular atrophy (Charcot-Marie-Tooth disease) Inherited sensorimotor neuropathy Several types:autosomal dominant and recessive Clinic: Distal limb wasting&weakness Pes cavus Clawing of toes Loss of sensation Loss of reflexes
Autonomic neuropathy Aetiology:DM,Guillain-Barre syndrome,amylodosis Clinic: Postural hypotension Retentions of urine Impotence Diarrhoea Diminished sweating Cardiac arrhythmias