gms | German Medical Science

72. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC)
Joint Meeting mit der Polnischen Gesellschaft für Neurochirurgie

Deutsche Gesellschaft für Neurochirurgie (DGNC) e. V.

06.06. - 09.06.2021

Normalisation of motor system excitability after bypass-surgery in patients with chronic cerebrovascular ischemia – a nTMS study

Die Erholung der Erregbarkeit des motorischen Systems bei Patienten mit chronischer hämodynamischer Ischämie nach Bypassanlage – eine nTMS-Studie

Meeting Abstract

  • presenting/speaker Pierre Rea-Ludmann - Charité Universitätsmedizin, Klinik für Neurochirurgie, Berlin, Deutschland
  • Fabia Roth - Charité Universitätsmedizin, Klinik für Neurochirurgie, Berlin, Deutschland
  • Thomas Picht - Charité Universitätsmedizin, Klinik für Neurochirurgie, Berlin, Deutschland
  • Peter Vajkoczy - Charité Universitätsmedizin, Klinik für Neurochirurgie, Berlin, Deutschland
  • Anna Zdunczyk - Charité Universitätsmedizin, Klinik für Neurochirurgie, Berlin, Deutschland

Deutsche Gesellschaft für Neurochirurgie. 72. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC), Joint Meeting mit der Polnischen Gesellschaft für Neurochirurgie. sine loco [digital], 06.-09.06.2021. Düsseldorf: German Medical Science GMS Publishing House; 2021. DocV242

doi: 10.3205/21dgnc229, urn:nbn:de:0183-21dgnc2291

Published: June 4, 2021

© 2021 Rea-Ludmann et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution 4.0 License. See license information at http://creativecommons.org/licenses/by/4.0/.


Outline

Text

Objective: Recently we have introduced the concept of the “hibernating brain” in patients suffering from chronic hemodynamic ischemia. In the state of misery perfusion an adaptive reorganization of the cortical motor network consisting of a reduced cortico-cortical excitability, elevated inhibition and enlarged cortical motor area was detected. Surgical revascularization by EC/IC bypass led to a recovery of impaired cortical motor function. The aim this study now was to assess changes of corticospinal excitability and axonal integrity during chronic ischemia and following surgical revascularization.

Methods: In this study 53 Patients were examined before and 3-6 months after EC-IC bypass surgery using navigated transcranial magnetic stimulation (nTMS). We examined the cortical excitability by determining resting motor threshold (RMT) and motor area, corticospinal inhibition by cortical silent period (CSP) and axonal integrity by means of recruitment curve (RC) of both hemispheres.

Results: Hemispheres affected by cerebrovascular impairment presented with a lower cortico-cortical excitability (RMT 41,8 % ± 9,5% compared to 39,5 % ± 7,8 %, p <.05), higher corticospinal inhibition (CSP 172,4ms ± 46,2 compared to 136,7± 47,0, p <.05) and wider motor areas as compared to the unaffected hemispheres (3,3 ± 1,9 cm2 compared to 2,5 ± 1,3 cm2, p <.05). Following bypass surgery an improved corticospinal conductivity (RC 5,5 ± 2,1 compared to 8,9± 2,7, p < .05) and normalization of cortical excitability (RMT 40,7 % ± 7,8 5 compared to 38,8 % ± 8,3 %, p < .05) could be observed.

Conclusion: We demonstrated that the ischemic brain is, after revascularization, capable of reorganizing and restoring neuronal function as shown by a lower resting motor threshold and a change in neuronal recruitment. These findings suggest a “hibernation” of the brain, a condition of impairment capable of preserving functional integrity in chronic ischemia.