The action of decamethrin (a synthetic pyrethroid) on the rat

When administered by a variety of routes decamethrin (NRDC 161) produced a clearly defined sequence of symptoms in the rat. These involved, progressively, chewing, salivation, pawing, choreoathetosis, tonic seizures, and death. Although animals showing tonic seizures almost invariably died, the choreoathetotic symptoms were largely reversible. Animals maintained adequate blood-gas values and arterial pressure until choreoathetosis was well advanced. Electroencephalograph records showed generalized spike and wave discharges during choreoathetosis and auditory or somatosensory-evoked spike discharges prior to choreoathetosis. Symptoms were partially antagonized by atropine. It is suggested that decamethrin-induced choreoathetosis may provide a useful model for the study of related human disorders.