The incidence of cerebral abnormalities using MRI in 30 consecutive children, aged 0.9-15.5 years, presenting with intractable complex partial seizures is reported from the Institute of Child Health and Hospital for Sick Children, London, UK. A clinical diagnosis of a temporal lobe focus was made in 19 patients, and all showed hippocampal, temporal lobe abnormalities, or both, on the MRI. Surgery performed in 2 confirmed the radiological diagnosis of hippocampal sclerosis in one and astocytoma in the other. Of 7 children without localizing features clinically, 5 had a hippocampal abnormality, one had atrophy of the right temporal lobe, and one had diffuse cortical change. Lateralizing features by EEG were recorded in 12 (41%), and 7 had an MRI abnormality on the same side. 
COMMENT. An MRI finding of hippocampal sclerosis was documented as early as 4 years of age in one patient in this study, and progressive hippocampal abnormalities over a six month period were apparent in one other. The MRI as employed in this study can separate the causes and effects of seizures and help to clarify the relationship between early hippocampal damage in children and subsequent temporal lobe epilepsy.
Studies of hippocampal neuron loss and memory scores, before and after temporal lobe surgery for epilepsy at the Reed Neurological Research Center, University of California, LA, support a role for the left hippocampus in rote verbal memory. Patients with severe as compared with minimal left hippocampal neuron loss may be at risk for lower memory functioning postoperatively.