Magnetoencephalographic and magnetic resonance spectroscopy evidence of regional functional abnormality in mesial temporal lobe epilepsy

Jerry J. Shih, Michael P. Weisend, John A. Sanders, Roland R. Lee

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

Mesial temporal lobe epilepsy (mTLE) with mesial temporal sclerosis (MTS) is a recognized epilepsy syndrome which is successfully treated with mesial temporal lobe resection. However, recent studies suggest that mTLE is more than a "focal" disease process. The objective of our study was to determine the presence and extent of functional abnormalities outside of a defined structural abnormality in epilepsy patients with mTLE. We used a prospective age-matched controlled design to study eight consecutive patients with MTS who were undergoing epilepsy surgery evaluation. Magnetoencephalography was used to localize the sources of electromagnetic abnormality. Proton magnetic resonance spectroscopy ( 1H-MRS) measured integrated peak areas for N-acetyl compounds (NAA) and choline-containing compounds (Cho) to determine regions of metabolic abnormality. All eight subjects had predominant electromagnetic abnormality in the temporal lobe ipsilateral to the MTS. All eight subjects had lower NAA/Cho ratios in the region of electromagnetic abnormality when compared to the homologous contralateral region (P < 0.001). Four subjects had predominant MEG spiking outside the mesial temporal region. Surgery-free outcome for the group with neuroimaging abnormalities outside of the medial temporal lobe is 50%. The region of maximal electromagnetic abnormality is outside the hippocampus in some patients with mTLE. These regions also demonstrate functional abnormalities. Our findings support the concept that mTLE is a more diffuse process than the hippocampal structural abnormality, which may impact surgical outcome.

Original languageEnglish (US)
Pages (from-to)368-374
Number of pages7
JournalBrain Topography
Volume23
Issue number4
DOIs
StatePublished - Jan 2011
Externally publishedYes

Fingerprint

Temporal Lobe Epilepsy
Electromagnetic Phenomena
Temporal Lobe
Magnetic Resonance Spectroscopy
Sclerosis
Epilepsy
Magnetoencephalography
Choline
Neuroimaging
Hippocampus

Keywords

  • Epilepsy
  • Magnetic resonance spectroscopy
  • Magnetoencephalography

ASJC Scopus subject areas

  • Clinical Neurology
  • Anatomy
  • Neurology
  • Radiology Nuclear Medicine and imaging
  • Radiological and Ultrasound Technology

Cite this

Magnetoencephalographic and magnetic resonance spectroscopy evidence of regional functional abnormality in mesial temporal lobe epilepsy. / Shih, Jerry J.; Weisend, Michael P.; Sanders, John A.; Lee, Roland R.

In: Brain Topography, Vol. 23, No. 4, 01.2011, p. 368-374.

Research output: Contribution to journalArticle

Shih, Jerry J. ; Weisend, Michael P. ; Sanders, John A. ; Lee, Roland R. / Magnetoencephalographic and magnetic resonance spectroscopy evidence of regional functional abnormality in mesial temporal lobe epilepsy. In: Brain Topography. 2011 ; Vol. 23, No. 4. pp. 368-374.
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