rss
J Neurol Neurosurg Psychiatry 2004;75:1309-1313 doi:10.1136/jnnp.2003.021972
  • Paper

Magnetoencephalography (MEG) predicts focal epileptogenicity in cavernomas

  1. H Stefan1,
  2. G Scheler1,
  3. C Hummel1,
  4. J Walter1,
  5. J Romstöck2,
  6. M Buchfelder2,
  7. I Blümcke3
  1. 1Department of Neurology, Epilepsy and Neuro-Center, University of Erlangen-Nürnberg, Erlangen, Germany
  2. 2Department of Neurosurgery, University of Erlangen-Nürnberg, Erlangen, Germany
  3. 3Department of Neuropathology, University of Erlangen-Nürnberg, Erlangen, Germany
  1. Correspondence to:
 Prof. Dr med. H Stefan
 Department of Neurology, Epilepsy and Neuro-Center, University of Erlangen-Nürnberg, Schwabachanlage 6, D-91054 Erlangen, Germany; hermann.stefanneuro.imed.uni-erlangen.de
  • Received 26 June 2003
  • Accepted 17 December 2003
  • Revised 13 November 2003

Abstract

Objective: The aim of this study was to identify the irritative epileptic zone in patients with cavernomas by means of magnetoencephalography (MEG).

Method: Among 82 patients operated for epilepsy, whose presurgical evaluation had included MEG, histological assessment of the tissue removed had confirmed cavernomas in eight. These eight patients had epilepsy since 18.6 (SD 12.7) years on average. The monitoring lasted about 2.1 (SD 1.3) hours and a median 20.9 (SD 14.3) spikes per hour were recorded. Spontaneous brain activity was recorded by means of a 74 channel dual unit MEG system (Magnes II, 4-D Neuroimaging) with simultaneous EEG recording (31 scalp electrodes). Spike analysis was performed using different source (moving dipole, current density reconstruction) and head models (spherical shells, BEM). Co-registration of neurophysiological and imaging data (MRI) was based upon anatomical landmarks.

Results: In 6/8 patients co-localisation from the cavernoma and epileptic zone was found. In two patients the focus was localised in the parieto-occipital lobe, in three patients in the frontal lobe and in three patients in the temporal lobe. In one case of temporal and one case of frontal lobe focus localisation there was no spatial relationship to the cavernoma.

Conclusion: In cases of focal seizures due to a single cavernoma, MEG may precisely delineate the epileptogenic tissue bordering the lesion. In patients with multiple cavernomas or dual pathology, MSI may reveal the complexity of the case, and contribute to the decision about further invasive diagnostics and more sophisticated therapeutic measures. MEG is a promising method for prediction of the epileptic zone in cavernoma related epilepsies, and thus it can contribute to decision making about and planning of epilepsy surgery.

Footnotes

  • This study was supported by DFG grant STE-380/9-2.

  • Competing interests: none declared

Register for free content

The full back archive is now available for all BMJ Journals. Institutional subscribers may access the entire archive as part of their subscription. Personal subscribers will also have access to all content when logged in. Non-subscribers who register have free access to all articles published before 2006 right back to volume 1 issue 1. Register here to access the free archive of all BMJ Journals.

Don't forget to sign up for content alerts so you keep up to date with all the articles as they are published.

BMJ Careers - Latest neurology and neurosurgery jobs