n-Hexane

In West Berlin in the autumn of 1975 through the following 5 months we observed 18 juvenile patients who had a toxic polyneuropathy and had sniffed a glue thinner. The neurological picture consisted of a symmetrical, progressive, ascending, mainly motor, polyneuropathy with pronounced muscle atrophy and characteristic vegetative alterations. The height of the disease was reached after 1 1/2-2 1/2 months and was characterized by tetraplegia in 7 patients. After 8 months all patients still had a motor deficit. Nerve biopsy showed paranodal axon swelling, dense masses of neurofilaments and secondary myelin retraction. The neurological and morphological data correspond to the "glue sniffer's neuropathy" and the n-hexane and MBK polyneuropathy after industrial exposure, as described in 10 cases to date. However, there was no MBK in the glue thinner. The polyneuropathies occurred in close time relation with the denaturation of the thinner with MEK (2-butanone). It is concluded from the data n-hexane and MBK have a common toxic mechanism with primary axonal changes and that there is an additional synergistic effect of MEK.

Although industrial exposure to n-hexane is known to cause neuropathy, it is less well recognized that inhalation of n-hexane present in the vapors of some commercial contact cements is also neurotoxic to peripheral nerves. A young man with a long history of addictive glue-sniffing developed severe distal symmetrical polyneuropathy several months after switching to a cement containing n-hexane and gradually improved several months after switching to another cement containing no n-hexane. Fascicular biopsy of radial cutaneous nerve showed striking segmental distention of axons by neurofilamentous masses with secondary thinning of myelin sheath, paranodal myelin retraction, and widening velocities were correspondingly slow. We conclude that n-hexane used as a solvent in some contact cements may be neurotoxic when inhaled to excess and, further, that the neuropathy has characteristic electrophysiological and pathological features.