Neuroimaging and neurophysiology of periodic lateralized epileptiform discharges: observations and hypotheses.

Full Abstract

PURPOSE: We assessed neuroimaging lesion type and distribution in patients with periodic lateralized epileptiform discharges (PLEDs), with a view to identifying electrographic differences between PLEDs associated with differing lesion locations. Our observations led us to consider a conceptual synthesis between PLEDs and periodic complexes (PCs). METHODS: Retrospective review of acute neuroimaging results (CT/MRI) on patients identified to have EEG PLEDs, for the period 1999-2003 (n=106). Blinded classification of original EEG recordings. RESULTS: Neuroimaging abnormalities were classified as acute or chronic cortical, or acute or chronic subcortical. Seven out of 106 scans were classified nonlesional. Overall approximately 70% of scans had cortical abnormalities, whether acute or chronic; approximately 23% had subcortical abnormalities. "Cortical" PLEDs were significantly longer in duration (p<0.05) and more variable in morphology (p<0.01) than "subcortical" PLEDs. CONCLUSIONS: Structural brain disease commonly, but not invariably, underlies PLEDs; lesion type is spatiotemporally variable. Cortical and subcortical PLEDs have distinct EEG signatures. There is evidence that these may relate to mechanisms for other pathological large-scale oscillatory brain synchronies (e.g., PCs).

Author information

Author/s: Kalamangalam, Giridhar P (GP); Diehl, Beate (B); Burgess, Richard C (RC);

Affiliation: Section of Epilepsy, Department of Neurology, Cleveland Clinic, Cleveland, Ohio, USA. Giridhar.P.Kalamangalam(-atsign-)uth.tmc.edu

Journal and publication information

Publication Type: Journal Article

Journal: Epilepsia (Epilepsia), published in United States. (Language: eng)

Reference: 2007-Jul; vol 48 (issue 7) : pp 1396-405

Dates: Created 2007/07/19; Completed 2007/08/09;

PMID: 17386051, status: MEDLINE (last retrieval date: 2/18/2009, IMS Date: )

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