Epilepsy in childhood: I. A statistical study of clinical types

Abstract

Summary 1. Some of the difficulties in making the diagnosis of epilepsy have been discussed. The difficulties usually depend upon incomplete history or observation. So-called “febrile convulsions” are sometimes confused with epilepsy. When seizures are of atypical nature rather than true convulsions, it is sometimes difficult to distinguish them from peculiar behaviorisms exhibited by defective children, syncope, hysteria, and breath-holding attacks. 2. The statistical studies reported here are based upon a group of 254 noninstitutionalized children thought to have epilepsy. All cases with questionable diagnosis were excluded from the group. 3. It is impossible at present to divide epilepsies into an “organic” and an “essential” group. It is probable that many epileptics with severe mental defects have organic cerebral lesions. However, since it is frequently impossible to determine whether a severe mental defect points to a preexisting cerebral malformation causing attacks, or is a result of deterioration following epilepsy, it is thought advisable to subdivide the cases into three groups, as follows: Group I. Patients with intelligence quotient above 80 and with no evidence of neurologic lesions (43.7 per cent) Group II. Patients with intelligence quotient below 80 but with no other evidence of neurologic lesions (32.3 per cent) Group III. Patients with definite evidence of neurologic lesions (24 per cent). 4. Fifty-four per cent of all the patients studied had I. Q.'s above 80; 57.5 per cent of the patients without neurologic lesions were standardized above 80, as compared with 41.5 per cent of the patients with neurologic lesions. 5. The character of the seizures in the three groups of epileptic children is discussed. A distinction is made between true petit mal seizures without motor manifestations and minor motor attacks. The convulsive discharge (either general or localized) was the predominant feature in 96.7 per cent of the epileptics with neurologic lesions, 69.5 per cent of those with mental retardation, and 62.2 per cent of the patients with approximately normal mentality. Only 16 patients, or 6.3 per cent of the entire series, had attacks exclusively of the petit mal type, and 15 of these patients were children of normal mentality. The petit mal attack was the predominant feature in 20.7 per cent of the group with normal mentality and in 6.1 per cent of the group of retarded children. The typical petit mal attack was not encountered in any of the patients diagnosed as having neurologic lesions. 6. A study of the frequency of seizures in the different groups of epileptic children does not gire a correct indication of the severity of the disease, due to the fact that petit mal seizures are more common among the children with normal mentality. When the frequency of convulsive attacks is compared in the different groups, it is found that the disease is relatively less severe in the children who have normal mentality. Conversely, mental defects are more often associated with the more severe forms. 7. The age of the onset of epilepsy is discussed. The symptoms are most liable to appear in the first two years of life. There is a decrease in the number of cases commencing between the second and the sixth years and another increase between the sixth and the eighth years. Other workers have shown a third increase in the frequency of onset occurring between the tenth and fifteenth years but this is not indicated by our figures due to the smaller number of children in the older age periods studied by us. The early onset, before the second year, is especially common in children having neurologic lesions since many of these lesions are the result of birth traumas or congenital malformations.