title: Is geomagnetic activity a risk factor for sudden unexplained death in epilepsies?
abstract: OBJECTIVE
  To test the hypothesis that sudden unexplained death (SUD) in epilepsy is related to geomagnetic activity.
  
  
  BACKGROUND
  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.
  
  
  METHODS
  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.
  
  
  RESULTS
  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).
  
  
  CONCLUSIONS
  The results do not support the hypothesis that geomagnetic activity is related to occurrence of sudden unexplained death in epileptic patients.
authors.affiliation: Institute of Neuropathology, Epilepsy Center Bethel, Bielefeld, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Schnabel
authors.forename: M
authors.initials: M
authors.lastname: Beblo
authors.forename: T W
authors.initials: TW
authors.lastname: May
mesh_terms: D000328:Adult; D003645:Death, Sudden / Q000209:etiology*; D018534:Earth, Planet; D004574:Electromagnetic Fields / Q000009:adverse effects*; D004827:Epilepsy / Q000401:mortality*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D013997:Time Factors