Relationship of hippocampal sclerosis to duration and age of onset of epilepsy, and childhood febrile seizures in temporal lobectomy patients

• Published in: Epilepsy research Vol. 24; no. 2; pp. 119 - 126
• Main Authors: Davies, Keith G., Hermann, Bruce P., Dohan, F.Curtis, Foley, Kevin T., Bush, Andrew J., Wyler, Allen R.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.06.1996
• Subjects: Adult; Age of Onset; Child; Electroencephalography; Epilepsy; Epilepsy - physiopathology; Febrile seizure; Female; Hippocampal sclerosis; Hippocampus - pathology; Hippocampus - physiopathology; Humans; Magnetic Resonance Imaging; Male; Regression Analysis; Sclerosis; Seizures, Febrile - physiopathology; Temporal Lobe - physiology; Temporal Lobe - surgery; Temporal lobectomy; Treatment Outcome; Hippocampal sclerosis; Febrile seizure; Epilepsy; Temporal lobectomy
• ISSN: 0920-1211; 1872-6844
• DOI: 10.1016/0920-1211(96)00008-3

Controversy exists as to whether hippocampal sclerosis (HS) is a preexisting cause or a consequence of seizures. We investigated 122 consecutive patients who underwent anterior temporal lobectomy for intractable epilepsy between 1989 and 1992. MRI scans were normal apart from evidence of HS in 5 cases. The degree of HS was graded from 0 to 4. There was a significant inverse correlation between age of seizure onset and grade of HS ( P < 0.0001), and a positive correlation between duration of epilepsy and grade of HS ( P < 0.001). Using a dichotomous grouping of HS (HPSC − for grades 0 and 1 [no/mild HS], and HPSC + for grades 3 and 4 [moderate/marked HS]), there was a positive correlation between HPSC + and a history of childhood febrile seizures (CFS) ( P = 0.003), earlier age of onset of epilepsy ( P < 0.001) and longer duration epilepsy ( P < 0.001). There was no correlation with history of particularly prolonged individual seizures. Partial correlations after controlling for age at onset of epilepsy showed that there was no longer a significant relationship between HPSC + and duration of epilepsy. After controlling for duration of epilepsy, the relationship between HPSC + and age of onset remained significant ( P < 0.001). The correlation between HPSC + and CFS, controlling for age at onset, was not significant. A series of logistic regression analyses showed age at onset to be the only predictor of HPSC +. It is concluded that this is supportive evidence for preexisting HS being a cause of temporal lobe epilepsy and not a consequence of seizures