Afterdischarges following F waves observed in a patient with tetanus.

We report a case of non-fluminent and mildly affected tetanus patient who showed afterdischarges following F waves in the affected extremity. The afterdischarges occurred following F waves and showed different configuration respond to each stimuli. Diazepam was also effective for spasms of our patient. This finding disappeared after treatment and showed a good correlation to clinical symptoms. These observations suggest that afterdischarges following F waves are induced by tetanus toxin which puts most of the motor neuron pool in a hyperactive state through its own action to the motor nerve including the spinal motor neuron.