Development of a subdural motor blockade.

We report an unusual development of motor blockade following the subdural injection of local anaesthetic during attempted continuous lumbar epidural anaesthesia. Four characteristic features of subdural block, extensive spread, segmental distribution, delayed onset, and short duration of motor blockade were all features of the case. The patient had gradual development of complete motor blockade in the left upper extremity, incomplete in the right upper extremity, but absence of motor blockade in the lower extremities. The duration of complete motor blockade was 10 min in the hand and 35 min in the arm. The spread of contrast medium in the subdural space revealed the extent and degree of motor blockade.