Is geomagnetic activity a risk factor for sudden unexplained death in epilepsies?

Abstract

To test the hypothesis that sudden unexplained death (SUD) in epilepsy is related to geomagnetic activity. Prior studies presume that geomagnetic activity (with average amplitudes above 50 nanotesla [nT]) is associated with SUD in epileptic human patients and in epileptic laboratory rats. In a retrospective study, 46 epileptic patients with definite SUD were compared with 108 epileptic patients with known cause of death (KCD) who died between 1981 and 1992. A complete postmortem examination was performed in all cases. The time of the day and date of death, as well as two international geomagnetic indices concerning Bartels' planetary 3-hour signs (Kp) and the mean planetary daily amplitudes (Ap) at time of death, were assessed. Among 45 SUD individuals, the local time (37.8%) and the universal time of death (35.6%) peaked within the critical period between 3 to 9 AM. However, the SUD and KCD group did not substantially differ in regard to the distribution of local or universal time of death (p > 0.2, Fisher test). Neither the Kp signs at death and 2 hours before death nor the Ap values showed considerable differences between the SUD and KCD series (p > 0.2, Mann-Whitney test). Merely 4.3% of SUD patients and 3.7% of KCD patients were associated with Ap indices above 50 nT (p > 0.2, Fisher test). The results do not support the hypothesis that geomagnetic activity is related to occurrence of sudden unexplained death in epileptic patients.