The effects of thiamylal sodium on electrical activities of the central and peripheral nervous systems in man

Abstract

The effects of thiamylal on the central and peripheral nervous systems of man were studied by simultaneous recording of somatosensory evoked responses from the scalp (SER), spinal epidural space (EESG), peripheral nerve (NAP) and muscle (EEMG). Clinical doses of thiamylal (2.5 mg/kg, 5 mg/kg) affect not only the SER but also the EESG and the H reflex of the EEMG, without significant effect on the M wave or NAP. Both early and late SER's were depressed in amplitude with prolongation of latency by the drug. The drug increased the amplitude of the N1 component of the EESG and prolonged P2 wave latency. Recovery of evoked responses after anesthesia was fastest with SER's and slowest with EEMG's. Thus, the changes caused by thiamylal in evoked responses in the peripheral and central nervous systems were not parallel in character or time course.