Interictal paroxysmal discharges in the electroencephalograms of epileptic dogs.

Paroxysmal discharges (PD) consisting of spikes, multiple spike complexes, sharp waves, multiple sharp-wave complexes, and spike-and-slow-wave complexes can be recorded in the interictal electroencephalograms of sedated epileptic dogs. With appropriate methods, focal PD can be detected and the hemisphere of origin and rostrocaudal location of their sources identified. Electrode montages that permit ready recognition of so-called instrumental phase reversal are especially helpful. PD that are presumably generalized can be recorded from dogs with signalments suggesting inherited/"idiopathic" epilepsy. These PD are described as "presumably" generalized because of the lack of recordings from ventral and ventrolateral cerebral regions. Further study is necessary, attempting to correlate types of PD with types of epilepsy.