The somatosensory evoked potential(SSEP) study has been used to evaluate the function along the somatosensory pathway from peripheral sensory receptor to the somatosensory cortex.

The prospective study was done to locate the anatomical lesion in 25 brain injured patients using SSEP study, neurologic sensory examination, brain C.T and the result of those studies are correlated. The SSEP study was done by median nerve stimulation at wrist and 3 channel recording at the ipsilateral Erb's point, cervical C2 vertebra and contralateral C3 or C4 of international 10-20 system.

The study reveals that the patients who showed absent N19 potential or prologed N13-N19 interpeak latency in SSEP have clinical sensory disturbances and lesions of the thalamus and/or internal capsule.

Keywords :Somatosensory evoked potential, Brain injury