gms | German Medical Science

56. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e. V. (DGNC)
3èmes journées françaises de Neurochirurgie (SFNC)

Deutsche Gesellschaft für Neurochirurgie e. V.
Société Française de Neurochirurgie

07. bis 11.05.2005, Strasbourg

Intraoperative microdialysis in brain tumour patients with symptomatic epilepsy

Intraoperative Mikrodialyse bei Hirntumorpatienten mit symptomatischer Epilepsie

Meeting Abstract

  • corresponding author J. Wölfer - Klinik und Poliklinik für Neurochirurgie, Universitätsklinikum Münster
  • C. Greiner - Klinik und Poliklinik für Neurochirurgie, Universitätsklinikum Münster
  • A. Gorji - Institut für Physiologie I, Universitätsklinikum Münster
  • E.-J. Speckmann - Institut für Physiologie I, Universitätsklinikum Münster
  • H. Wassmann - Klinik und Poliklinik für Neurochirurgie, Universitätsklinikum Münster

Deutsche Gesellschaft für Neurochirurgie. Société Française de Neurochirurgie. 56. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e.V. (DGNC), 3èmes journées françaises de Neurochirurgie (SFNC). Strasbourg, 07.-11.05.2005. Düsseldorf, Köln: German Medical Science; 2005. Doc11.05.-12.06

Die elektronische Version dieses Artikels ist vollständig und ist verfügbar unter: http://www.egms.de/de/meetings/dgnc2005/05dgnc0238.shtml

Veröffentlicht: 4. Mai 2005

© 2005 Wölfer et al.
Dieser Artikel ist ein Open Access-Artikel und steht unter den Creative Commons Lizenzbedingungen (http://creativecommons.org/licenses/by-nc-nd/3.0/deed.de). Er darf vervielf&aauml;ltigt, verbreitet und &oauml;ffentlich zug&aauml;nglich gemacht werden, vorausgesetzt dass Autor und Quelle genannt werden.


Gliederung

Text

Objective

One third of all brain tumour patients become symptomatic with one ore more epileptic fits. Pathophysiologic mechanisms leading to epilepsy in brain tumour patients are largely unknown even though clinical observation and electroencephalography point towards infiltration and edema zones as the most likely areas of ictus origin. Intraoperative microdialysis within the border zone of tumours is supposed to yield data concerning the pathophysiologic basis of epileptogenesis in brain tumours primarily by detection of extracellular ion concentrations.

Methods

We aim at brain tumour patients suffering from epileptic fits and whose tumours reach the cortex. The latter point allows for placement of three microdialysis probes within the area which is planned for later resection during tumour surgery: a) into tumour tissue proper, b) into the border zone as determined by navigation (“peritumoral tissue”), c) into deafferentiated surrounding (“paratumoral”) tissue. Microdialytic sampling takes place for one hour following a schedule approved by the local ethics committee and which the patient has taken notice of. For this period of time the probes are securely fixed by a specially developed mount. Corticography during intermittent cortex stimulation is performed simultaneously with microdialysis. Following the measurements the areas adjacent to the probes are resected separately and examined electrophysiologically as well as by receptor autoradiography. Sodium, potassium, calcium, and chloride concentrations are determined from 10 consecutive microdialytic samples in each patient. To date, samples have been collected in one patient with glioma and in one with brain metastasis.

Results

Electrolyte measurements in a glioma patient show a massive rise of interstitial potassium which decreases from the tumour center outwards and reaches up to 9mMol/l, while serum potassium levels are normal. Calcium levels behave vice versa, rising from less than 1mMol/l in the center to the double within tumour periphery. Trends of the dialysates collected during cortex stimulation are not yet clear, while a different aetiology (metastasis) shows different behaviour of electrolyte levels.

Conclusions

Microdialytic measurements point towards massive electrolyte disturbances as one of the conditions under which tumour epilepsy can arise. After the preconditions for longer term measurements have been created, our group strives towards a greater number of analyses to consolidate our first data.