Neuropathy Pain May Increase Due to PCBs

Some of the persons involved in an outbreak of ''yusho'' (polychlorinated biphenyl poisoning due to contaminated cooking oil) in Japan during the summer of 1968 complained of numbness or neuralgic limbs. Therefore, peripheral sensory nerve conduction velocity was measured in 21 such patients, and motor nerve conduction velocity in 19 of these. The motor nerve conduction velocity in the ulnar nerve was within the normal range in all of the patients; that in the tibial nerve was also normal, except in one patient with deep reflexes absent in all four limbs. In ten cases (48%), the sensory nerve conduction velocity was lower than normal in the radial or the sural nerves or both. In the group which displayed neuropathic symptoms in the lower limbs (about half of the total) six cases (75%) showed a slowing of conduction velocity in the sural nerve, whereas only one patient in the nonneuropathic group displayed reduced conduction velocity. These findings apparently represent early manifestations of a mixedtype polyneuropathy. (Murai et al, 1971)