Apnoea and bradycardia during epileptic seizures: Relation to sudden death in epilepsy
Nashef L, Walker F, Allen P, Sander JW, Shorvon SD, and Fish DR (1996) Apnoea and bradycardia during epileptic seizures: Relation to sudden death in epilepsy. J Neurol Neurosurg Psychiatry 60:3 297–300.
Abstract: OBJECTIVE: To record non-invasively ictal cardiorespiratory variables. METHODS: Techniques employed in polysomnography were used in patients with epilepsy undergoing EEG-video recording at a telemetry unit. RESULTS: Apnoea (> 10, range > 10-63, mean 24 s) was seen in 20 of 47 clinical seizures (three secondary generalised, 16 complex partial, and one tonic) and 10 of 17 patients. Apnoea was central in 10 patients, but obstructive apnoea was also recorded in three of 10. Oxyhaemoglobin saturation (SpO2) dropped to less than 85% in 10 seizures (six patients). An increase in heart rate was common (91% of seizures). Bradycardia/sinus arrest was documented in four patients (mean maximum RR interval 5.36, range 2.8-8.6 s) but always in the context of a change in respiratory pattern. CONCLUSION: Ictal apnoea was often seen. The occurrence of bradycardia in association with apnoea suggests the involvement of cardiorespiratory reflexes. Similar mechanisms may operate in cases of sudden death in epilepsy.
Keywords: ictal apnoea, ictal bradycardia, sudden death in epilepsy
Context
- Recording cardiorespiratory variables along with EEG in epilepsy monitoring unit identified apnea in 20 of 47 seizures (10 of 17 patients). With apnea defined as 10 s cessation of breating, complex partial seizures were 80% of apnea-inducing seizures (74% of total seizures). All 3 secondarily generalized seizures observed led to apnea. Tachycardia was common, but bradycardia or asystole was observed in 4 patients. This was viewed as always occurring in conjunction with respiratory changes.