Somatosensory evoked potential (SEP) is a good indicator of evaluation for the brain dysfunction and its neurophysiologic state; the informations of SEP itself, especially the generator and significance of it's potentials are so poor. And so SEP offers little basis for reflecting the neurophysiologic a state and objective scale of the improvement in brain dysfunction. We examined the median nerve SEPs (MNSEP), brain computerized tomogram and clinical findings of 100 MNSEPs in three different ways and correlated them with the clinical finding.
Results
are as followings.

1) SEP is helpful to predict the functional prognosis in hemiplegics, because all 3 kinds of the MNSEP classification correlated with all physical findings in statistical significance.

2) The more simple the classification is, the more it is correlated with the motor findings. And the more subdivided the classification is, the more it is correlated with the sensory findings, especially stereognosis and position sense.

3) SEP has highest correlation with the stereognosis, position, touch, temperature, vibration sense in that order, but also SEP showed considerable correlation with motor findings.

4) The third method of 3 MNSEP classifications is considered as best reflector of neurophysiologic state in hemiplegics.