Hippocampal damage in newly diagnosed focal epilepsy: a prospective MRI study.
OBJECTIVE
To examine the longitudinal appearance of hippocampal (HC) damage in a prospective follow-up study of patients with newly diagnosed epilepsy.


METHODS
A total of 103 patients with newly diagnosed focal epilepsy were scanned with MRI before antiepileptic medication was started. Serial MRI studies were scheduled after 1, 2 to 3, and 5 years of treatment in the ongoing follow-up study. Volumes of the HC were measured from MRI scans according to the Cavalieri method of modern design stereology and compared at different time points together with clinical variables.


RESULTS
No difference was observed in the mean HC volumes between controls and patients at baseline, after 1, 2 to 3, and 5 years of follow-up. Individual analysis showed that 8% of patients had HC damage at the time of the diagnosis and 13% of patients developed HC volume decrease during 2 to 3 years of follow-up. These patients had longer duration of seizure disorder and larger seizure number before the epilepsy was diagnosed and treatment started compared with patients who did not show HC damage.


CONCLUSIONS
Hippocampal volume decreases occur in individual patients with newly diagnosed focal epilepsy during the first years of treatment. The data obtained suggest that hippocampal volumetry provides a surrogate marker of the epileptic process.
Salmenperä
T
T
Department of Neurology, Kuopio University Hospital, Kuopio, Finland.
Könönen
M
M
Roberts
N
N
Vanninen
R
R
Pitkänen
A
A
Kälviäinen
R
R
D000293:Adolescent; D000328:Adult; D000368:Aged; D001925:Brain Damage, Chronic / Q000150:complications* / Q000473:pathology; D004828:Epilepsies, Partial / Q000175:diagnosis*; D005260:Female; D005500:Follow-Up Studies; D006624:Hippocampus / Q000473:pathology*; D006801:Humans; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D011446:Prospective Studies