Sensory and motor nerve conduction velocity in long-term diphenylhydantoin therapy.

Since Merrit and Putnam (1938) 8 introduced the diphenylhydantoin (DPH) in the treatment of epilepsy, it has been used largely as the main drug in many forms of the disease. Several attempts have been made to demonstrate its action on the peri­ pheral nerve, but the obtained results are controversial. Korey 6 first, and Morrell, Bradley and Ptashne after, gave experimental evidence of DPH toxic effect on the nerve. Histologically Guercio, Sica, Taratuto and Poch : i demonstrated a demyelinating effect on the peripheral nerve of men which was correlated with prolonged administration of the drug. Brumlik and Moretti 2 failed to demonstrate any abnormality in motor or sensory nerve conduction velocity in patients under DPH therapy; however Hopf 5 found slowing of slowly motor conduction nerve fibres, while others 3 . 7 found a slowing of the maximum nerve motor conduction velocity, which suggest that the fastest fibres in the nerve are damaged as well. We now wish to report our findings in epileptic patients under DPH therapy. The background of this investigation was to estimate the motor and sensory conduction velocities in the median nerve, in an attempt to elucidate further the effect of DPH on peripheral nerve.