Slow sharp waves.

Slow sharp waves (SSHW) are of longer duration (around 200 msec and longer) than typical sharp wave discharges (70 to 200 msec). This pattern is not merely of academic interest, as the electroclinical correlation showed that SSHW were found in 23 patients, mostly above age 50 years, with serious illnesses of various etiologies. Epileptic seizures occurred in a minority of the cases. The electrophysiological basis remains unclear and there is no answer to the question, "what causes the relatively long duration of these discharges?"