Clinical, EEG, and neuroimaging findings in a community-based cohort of 63 children with new-onset temporal lobe epilepsy (TLE) studied prospectively are reported from the Royal Children’s Hospital, Melbourne, Australia. Three etiologically defined subgroups of TLE are proposed based on clinical history and MRI or CT findings: 1) Cryptogenic, with normal MRI and negative past history (54%); 2) Hippocampal sclerosis, or previous illness (29%); and 3) Developmental, malformation or tumor (16%). Febrile seizures had preceded onset of TLE in 13 children, and bacterial meningitis in 4. Neuroimaging revealed structural abnormalities of the temporal lobe in 24 (38%); hippocampal sclerosis in 13 (21%), tumor in 8 (13%). Focal temporal EEG abnormalities were recorded in 19 of 24 with lesions on MRI or CT and in 27 of 39 with normal neuroimaging. Developmental, behavioral, or learning problems occurred in 38% of the cohort. Behavior problems included hyperactivity (14), aggressiveness (13), and rage attacks (5). [1]

COMMENT. This extensive prospective study has provided a classification of temporal lobe epilepsy in childhood of value in prognosis and management. Temporal lobe epilepsy in childhood is classified etiogically in three groups: 1) cryptogenic, 2) hippocampal sclerosis, and 3) developmental. Children with cryptogenic seizures have a relatively good prognosis, whereas those with hippocampal sclerosis or developmental lesions are at risk of resistant seizures and psychological disabilities. For previous reports from the Melbourne, Australia group, the Cleveland Clinic experience, and that of the University of California, Los Angeles, see Progress in Pediatric Neurology II, 1994;pp78-79. Vol III, 1997;pp54-55.

SPECT-EEG correlations in temporal lobe epilepsy are reported from Yonsei University Coll Med, Severance Hospital, Seoul, Korea [2]. Interictal SPECT correctly lateralized 8/9 patients with unitemporal epileptiform discharges and 5/10 with bitemporal EEG discharges. Ictal SPECT was highly concordant with ictal EEG, but correctly lateralized the lesion in only 11/19.

In the Melbourne experience (Harvey et al. 1993), ictal SPECT lateralized lesions and correlated with EEG and MRI findings; it was superior to ictal EEG in localizing value in some. (PPN II, 1994;p79).

Mesial temporal spikes interfere with working memory in a report of 8 adult patients with depth electrodes implanted to evaluate intractable epilepsy, at Johns Hopkins Epilepsy Center, Baltimore, MD [3]. The greatest impairment of spatial and verbal recall coincided with left hippocampal spiking.