RECORDING RESPIRATORY PARAMETERS IN PATIENTS WITH EPILEPSY

Anecdotal evidence and data from small studies suggest that respirator y changes occur in both complex partial and generalized seizures. Our understanding of sudden unexpected death in epilepsy (SUDEP) may be fu rthered by recording and analyzing these changes. Investigators at the Jules Thorn Telemetry Unit at the National Hospital for Neurology and Neurosurgery have documented a range of respiratory parameters (respi ratory effort. airflow, oxygen saturation) in conjunction with time-lo cked audio-video electroencephalograms and electrocardiograms to provi de a more complete picture of the physiologic changes that occur jurin g seizures. Cardiorespiratory information on 79 seizures (70 complex p artial, nine generalized) in 37 patients (20 male, 17 female) is prese nted. Whereas tachycardia was a common ictal feature, bradycardia was seen only rarely and tended to follow a period of apnea. Apnea occurre d in 100% of generalized seizures and 39% of complex partial seizures. Apnea was predominantly central and lasted for 10-75 s (mean duration 29 s). Central apnea may be one of the major, although by no means ex clusive, ictal events predisposing to SUDEP.