Fever as a seizure precipitant factor in Panayiotopoulos syndrome: a clinical and genetic study

To examine fever as a precipitating factor for focal seizures in patients with Panayiotopoulos syndrome (PS) and evaluate the role of SCN1A in PS patients with seizures triggered by fever.

From January 2000 to June 2008, we identified patients referred for seizures who fulfilled the criteria of PS. Patients were divided into two groups, according to the presence (group A) or the absence (group B) of seizures triggered by fever. Electroclinical features of the two groups were compared. In addition, an analysis of SCN1A in patients of group A was performed.

Thirty patients fulfilled the inclusion criteria. Eleven patients (36%) had at least one focal autonomic seizure triggered by fever (group A). In group A, 7/11 patients (63.5%) had the first focal autonomic seizure during a febrile illness. Two of these 7 patients were misdiagnosed at the onset of PS. The median age at the onset of PS was slightly lower in group A than in group B (p=.050). Moreover, patients in group A more frequently had a positive familial history of febrile seizures (FS) (p=.047). No mutations of SCN1A were found in any of the 10 patients screened.

Fever is a common trigger for focal autonomic seizures in PS. Knowing that an autonomic manifestation during fever can be an epileptic seizure could facilitate diagnosis and prevent unnecessary investigations and erroneous treatments. Moreover, our data show that SCN1A gene does not contribute significantly to susceptibility to autonomic seizures during fever in patients with PS.