Electrophysiological studies on rabbits in long-term exposure to carbon disulfide

Electroneuromyography was performed as part of a multidemensional study of experimental carbon disulfide poisoning of rabbits. Ten rabbits were exposed by inhalation of 750 ppm of carbon disulfide for 6 hours a day, 5 days a week for 10 weeks. A slowing of the motor conduction velocity of the sciatic nerve was clearly observable during the course of exposure. This slowing preceded clinical paralysis, which became severe in the hind limbs within 9 weeks. Although the amplitude of the motor response to stimulation diminished markedly towards the end of the exposure period, a response of about 2 mV was always elicitable. Definite fibrillations could be noted in the gastrocnemius muscle of the rabbits after exposure for 9 weeks. In the two rabbits allowed to recover, the fibrillations continued for up to 2 months after the cessation of the carbon disulfide exposure. As the paralysis was very severe, even though the nervous conductivity was rather well preserved, it was assumed that a lesion at the spinal cord level was combined with neuropathy. These experimental findings from rabbits agreed well with results from clinical studies of workers occupationally exposed to carbon disulfide. Some similarities, but also differences, were observable between neurophysiological findings in carbon disulfide and other forms of experimental toxic neuropathy.