Classification of benign infantile afebrile seizures

Abstract

Purpose: The aim of this study is to classify infantile cases with benign seizures into known epileptic syndromes, thereby facilitating discussion of clinical factors that could play an important role in diagnosis.

Subjects: Fifty-seven patients with afebrile seizures fulfilling all of the following criteria were enrolled: (1) normal development prior to the onset, (2) no underlying disorders nor neurological abnormalities, (3) onset before the age of four and (4) normal interictal EEG and neuroimaging findings.

Results: Thirty-nine cases (Group A) were characterized by an association of mild gastroenteritis. The remaining 18 cases were divided into two groups according to the seizure type. One group had partial seizures (Group B, 13 cases) while the other was suspected to have generalized seizures (Group C, 5 cases). Age at onset was significantly higher for Group A (19.5 +/- 5.5 months) than Groups B (5.3 +/- 1.8 months) (p<0.001) and C (5.8 +/- 3.5 months) (p=0.038). Positive family history of seizure disorder, seizure cluster tendency, and the efficacy of lidocaine against seizure clusters were common in the three groups.

Conclusions: Features in Group A were consistent with benign convulsions with mild gastroenteritis (proposed by Morooka) [Morooka, K., 1982. Mild diarrhea and convulsions. Shonika 23, 134-137 (in Japanese)], those of Group B with benign partial epilepsy in infancy [Watanabe, K., Yamamoto, N., Negoro, T., Takaesu, E., Aso, K., Furune, S., Takahashi, I., 1987. Benign complex partial epilepsies in infancy. Pediatr. Neurol. 3, 208-211], and those of Group C with benign infantile convulsions [Fukuyama, Y., 1963. Borderland of epilepsy with special reference to febrile convulsions and so-called infantile convulsions. Seishin Igaku 5, 211-223 (in Japanese)]. The distinction between these syndromes depends upon age at onset, association with gastroenteritis, and ictal symptomatology. In our experience, however, it was not easy to catch seizure type accurately in clinical situations. As far as the results of ictal video-EEG monitoring ever carried out concern, focal initiation of parxysmal discharges was demonstrated in all cases, not only of BPEI but also of apparent generalized seizures examined without exception. These observations led the authors to conclude that the identity of BIC is dubious, most probably it will represent a subtype of BPEI.