Temporal lobe dysembryoplastic neuroepithelial tumour: significance of discordant interictal spikes.
OBJECTIVE
Dysembryoplastic neuroepithelial tumours (DNET) are an important cause of refractory partial epilepsies. They usually occur within dysplastic cortex and tend to affect the temporal lobes. The EEG of these patients is characterised by slowing and/or epileptiform abnormalities with a multifocal distribution. We studied the EEG features of epilepsy patients with a temporal lobe DNET to assess the relationship of EEG abnormalities with the localisation of the tumour and the clinical features.


METHODS
We retrospectively reviewed 16 patients with unilateral, temporal lobe DNET on MRI. The EEG abnormalities were classified as concordant to the lesion when the EEG discharges were confined to the ipsilateral temporal lobe or discordant when EEG discharges were found in other areas. Clinical and epilepsy characteristics were compared between patients with concordant and discordant EEG.


RESULTS
Focal EEG abnormalities were found in 81% of the patients; 6/16 patients had concordant EEG abnormalities, and 7/16 patients had discordant EEG abnormalities. Epilepsy severity prior to the operation, antecedents and post-operative outcome were not different between patients with concordant or discordant EEG abnormalities.


CONCLUSIONS
Patients with temporal lobe DNET often show EEG discharges discordant to the tumour. However, they do not appear to predict the clinical and epilepsy characteristics of these patients.
Labate
Angelo
A
Brain Research Institute, Heidelberg, Melbourne, Australia.
Briellmann
Regula S
RS
Harvey
Anthony S
AS
Berkovic
Samuel F
SF
Federico
Paolo
P
Kalnins
Renate M
RM
Fabinyi
Gavin C
GC
Jackson
Graeme D
GD
D000328:Adult; D004569:Electroencephalography; D004828:Epilepsies, Partial / Q000175:diagnosis / Q000209:etiology*; D004833:Epilepsy, Temporal Lobe / Q000175:diagnosis / Q000209:etiology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D018302:Neoplasms, Neuroepithelial / Q000150:complications* / Q000473:pathology*; D012189:Retrospective Studies; D012720:Severity of Illness Index; D013702:Temporal Lobe / Q000473:pathology*; D013724:Teratoma / Q000150:complications* / Q000473:pathology*