Sex differences and lateral asymmetry in heart rate modulation in patients with temporal lobe epilepsy

This study was designed to study the influence of gender and lateral hemispheric asymmetry on heart rate modulation during temporal lobe seizures. Heart rate was recorded during complex partial seizures in 10 female and 11 male patients (12 with a right temporal lobe focus, nine with a left focus), with simultaneous video monitoring and bilateral subdural electrode placement. Heart rate changes were analysed during the seizure, at a time when the epileptic activity was restricted to one hemisphere. In this analysed interval, the heart rate of patients with a right temporal lobe focus showed a significant increase, from 73.5 to 91.0 beats/min (F=10.7, df=2.3/27, p < 0.001), while the heart rate of patients with a left sided focus only increased slightly, from 77.0 to 82.5 beats/min (NS). An effect of sex was demonstrated, in that the influence of focus laterality could only be shown in male patients (F = 14.24, df = 2.58/27, p < 0.001). These results confirm the right hemispheric lateralisation of sympathetic cardiac control in male patients.