Aktuelle Neurologie 2007; 34 - V255
DOI: 10.1055/s-2007-987570

Hippocampal abnormalities in patients with malformations of cortical development and epilepsy

G Kuchukhidze 1, I Unterberger 1, J Dobesberger 1, N Embacher 1, G Walser 1, E Haberlandt 1, F Koppelstätter 1, T Gotwald 1, H Maier 1, M Ortler 1, S Felber 1, E Trinka 1
  • 1Innsbruck, A

Purpose: Malformations of cortical development (MCD) represent a heterogeneous group of brain abnormalities determined by disrupted stages of neuronal development. They are increasingly recognised as a major cause for medically refractory epilepsy, focal neurological deficits and cognitive disturbances. There have been few reports on hippocampal abnormalities (HA) associated with MCD. This study aimed to identify the spectrum and frequency of HA in patients with MCD and epilepsy.

Methods: We identified 137 patients (75w/62m) aged 1–74 years (mean 31 years) with MCD and epilepsy from our department database. All patients were clinically examined, underwent EEG recordings and high resolution MRI. Assessment of hippocampal formation was done on 3mm coronal T2-weighted and FLAIR sequences. Twenty seven patients underwent epilepsy surgery.

Results: HA was identified in 42/137 (31%) patients with MCD and epilepsy. This number did not include 16 patients in whom hippocampus was a part of MCD. Eighteen patients had hippocampal sclerosis, in 24 patients hippocampus was malrotated and its shape was distorted. Twenty four patients had bilateral HA, in 18– HA was associated with increased MR signal in T2-weighted and FLAIR sequences. Six patients had febrile seizures during childhood, 9 had documented status epilepsticus during the course of epilepsy, none had history of perinatal ischemic brain injury. The spectrum of MCD included 31 patients with focal cortical dysplasia, 24– with ganglioglioma/gangliocytoma, 13– with tuberous sclerosis, 9– with hemimegalencephaly, 4– with microcephaly, 24– with periventricular nodular heterotopia, 2– with lissencephaly/pachygyria, 1– with subcortical laminar heterotopia, 29 -with polymicrogyria (with or without schizencephaly). There was no clear association between different types of MCD and frequency of HA.

Conclusions: HA is observed in one third of patients with MCD and epilepsy. The dual pathology has important implications for presurgical assessment of patients with pharmacoresistant seizures.