title: Exacerbation of pre-existing epilepsy by mild head injury: a five patient series.
abstract: OBJECTIVE
  While the risk of developing seizures following a mild head injury has been reported and is thought to be low, the effect of mild head injury on patients with a pre-existing seizure disorder has not been reported. We present a series of cases where a strong temporal relationship between mild head injury and worsening of seizure frequency was observed.
  
  
  METHODS
  Five cases were identified and reviewed in detail. Information was derived from clinic and hospital charts with attention to the degree of injury, pre- and postinjury seizure patterns and frequency.
  
  
  RESULTS
  One patient has primary generalized epilepsy and four have localization related epilepsy. Prior to the head injury, three of the patients were seizure free (range: two to 24 years). The patients suffered from mild head injuries with no or transient loss of consciousness and no focal neurological deficits. In all cases, the patients experienced a worsening of seizure control within days of the injury. In one case, the patient's seizure pattern returned to baseline one year after the accident, while in the remaining four cases, the patients continue to have medically refractory seizures.
  
  
  CONCLUSIONS
  A close temporal relationship between mild head injury and a worsening of seizure control was observed in five patients with epilepsy. Although further study is required, this observation suggests that a head injury that would be considered benign in the general population can have serious consequences such as recurrence of seizures and medical intractability in patients with epilepsy.
authors.affiliation: Division of Neurology, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: P C
authors.initials: PC
authors.lastname: Tai
authors.forename: D W
authors.initials: DW
authors.lastname: Gross
mesh_terms: D000328:Adult; D006259:Craniocerebral Trauma / Q000150:complications*; D004827:Epilepsy / Q000150:complications* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D012008:Recurrence; D012189:Retrospective Studies; D012720:Severity of Illness Index