Sensory dysfunction in GB syndrome: a clinical and electrophysiological study of 100 patients

Studies of sensory system involvement in Guillain Barre' (GB) Syndrome are sparse in the literature. This communication presents the clinical and electrophysiological data of 100 patients of GB Syndrome evaluated over 5 years at NIMHANS, Bangalore, India. Sensory symptoms or signs were present in 45% and 59% of patients in upper and lower limbs respectively and were distal and symmetrical. Impairment of joint position and vibration sense was the commonest finding and was associated with a greater need for ventilatory support and autonomic disturbances. Sensory nerve conduction studies involved median, ulnar and sural nerves and electrophysiological evidence of abnormality was present in at least one sensory nerve in 80% of cases. These were: absent sensory nerve action potential (SNAP) in 19%-41%, reduced SNAP amplitude in 28-34% and reduced conduction velocity in 8%-15%. "Abnormal Median and normal Sural response", the pattern characteristic of demyelinating neuropathy, was noted in 29% of the cases. While sensory symptoms and signs were more frequent in lower limbs, electrophysiological abnormalities were more frequent in median and ulnar nerves. There was good association between motor and sensory conduction parameters in median and ulnar nerves. The time of performance of nerve conduction studies did not influence the results. Electro-clinical study of sensory system adds to our understanding of GB Syndrome.