Among abstracts of the 19th annual conference on febrile convulsions, Tokyo, Japan, Dec 14, 1996, and reviewed by Dr Yukio Fukuyama , four referred to the association with viral infection.
Abe T, Teikyo University School of Medicine, Tokyo, studied the mechanism of convulsions associated with rotavirus (RV) infection. Three percent of children with RV diarrhea develop convulsions compared to 0.3% with non-RV diarrheal infections. The mechanism may involve electrolyte imbalance or the direct invasion of neurons by RV virus or enterotoxin.
Asano Y et al, Fujita School of Medicine, Toyoahe, Aichi, report on human herpesvirus 6 (HHV-6B) as a cause of febrile seizures in 8 - 36% of children with exanthem subitum. The viral DNA is found in CSF samples within 4 days after onset of infection. Afebrile seizures may also occur with HHV-6 infection and exanthem subitum and without evidence of invasion of the CNS by the virus. A vasculitis is proposed as the mechanism of afebrile seizures with HHV-6 infection. (Ojima K et al).
Kajitani T et al, Kawasaki Hospital, Okayama, reviewed the causes of fever in 197 children admitted with febrile seizures. Viral infections accounted for 82%, of which 3% were exanthem subitum.
COMMENT. Seizures with fever, HHV-6 and exanthem subitum are frequently prolonged, recurrent, and complex, and sometimes a manifestation of encephalitis or encephalopathy. HHV-6 infection and febrile seizures are reviewed in Progress in Pediatric Neurology III, 1997, pp 24-28; VOL II, pp 27-28.