Due to paucity of a comprehensive study on somatosensory and motor evo
ked potentials in thalamic hemorrhage, the present study has been unde
rtaken. Clinical examination, motor evoked potential(MEP) and median s
omatosensory evoked potential(SEP) studies were performed on 22 consec
utive patients with CT-proven thalamic hemorrhage. The clinical and ev
oked potential studies were carried out on admission and repeated at t
he end of 3 months. The hematomas were classified as type A (with post
erolateral extension) and type B (without posterolateral extension). T
he hematomas were of type A and type B in II patients each. The patien
ts with type A hematomas had persistent inexcitability of motor pathwa
ys and SEPs were unrecordable. In type B, MEP was not recordable in th
ree, prolonged in five and normal in three patients; in all these pati
ents, MEP returned to normal in the follow-up study. The cortical pote
ntials of median SEP were normal in four and unrecordable in five pati
ents with type B hematoma. In the follow-up study, SEPs became recorda
ble in all, although central sensory conduction time (CSCT) was prolon
ged in three patients. MEP and SEPs were related to the respective mot
or and sensory dysfunction and to posterolateral extension of hematoma
. Patients with type A hemorrhage had worse prognosis compared to type
B, emphasising the importance of posterolateral extension. A persiste
ntly unrecordable MEP and SEP in thalamic hemorrhage suggests a poster
olateral extension which predicts a poor outcome.