Benign familial and non-familial infantile seizures: a study of 64 patients

Abstract

Introduction: The recently proposed diagnostic scheme for people with epileptic seizures and with epilepsy (Epilepsia 2001) includes two idiopathic focal epileptic syndromes with onset during the first year of life, the benign familial and non-familial infantile seizures.

Objectives: To analyze the electroclinical features and evolution in patients with benign familial and non-familial infantile seizures.

Patients and methods: Sixty-four patients (36 males and 28 females) were evaluated at the Neurology Department of the J. P. Garrahan Children's Hospital between February 1990 and December 2001. We analyzed gender, age at onset, duration, manifestations, circadian distribution and frequency of seizures, family history of epilepsy and paroxysmal dyskinesias. EEG and neuroradiological studies were performed. The semeiology of the seizures was analyzed only according to the description in the clinical history. Ictal EEGs could not be recorded.

Results: Twenty-five patients, 14 girls and 11 boys, had a family history of similar seizures with an age at seizure onset of 3 to 22 months (median of 5.5 months). Nine patients (36%) had apparently generalized convulsions only; five patients (20%) partial seizures only and ten patients (50%) had both partial and generalized seizures. Convulsions were brief, during wakefulness in all, and occurred in clusters in 12 patients (48%). Interictal EEG was normal in 24 patients (96%). Similar seizures and age at onset were found in 14 fathers, ten mothers and one uncle of these patients. Twenty-two patients (88%) had their last seizure before the age of 30 months. Two siblings of the same family later had brief episodes of paroxysmal kinesigenic dyskinesia, which in one of them were associated with infantile seizures. Later, two fathers developed paroxysmal kinesigenic dystonia. One of them also had had infantile seizures. A second group of 39 patients (25 boys and 14 girls) showed similar electroclinical features and evolution but there was no history of infantile seizures in first-degree relatives family history of epilepsy was found in 12.8% of second-degree relatives, but the type of epilepsy could not be defined.

Conclusion: This study confirms the existence of a familial benign epileptic syndrome in infancy, of probable dominant autosomical transmission. A large group also had similar electroclinical features but without a family history. We discuss the possible relationships between the two groups and suggest that further genetic studies may solve the problem.