Intraoperative three-dimensional visualization of the pyramidal tract in a neuronavigation system (PTV) reliably predicts true position of principal motor pathways.
BACKGROUND
This prospective study employs anisotropic diffusion-weighted (ADW) magnetic resonance imaging for the integration of individual spatial information concerning the principal motor pathways into the operating room during microneurosurgery in the central region. We hypothesize that the three-dimensional (3-D) visualization of the pyramidal tract position (PTV) in a neuronavigation system based on ADW provides valid information concerning the position and extension of the principal motor pathways.


METHODS
A total of 13 consecutive patients with lesions adjacent to the pyramidal tracts and the central region underwent microneurosurgery with the help of pyramidal tract visualization (PTV). An ADW sequence obtained preoperatively was fused to an anatomic navigation sequence. The 3-D reconstructions of the precentral gyrus (PG), the pyramidal tract, and the tumor were available in a customized neuronavigation system during surgery. Intraoperatively the PG was identified on the basis of the aforementioned data. Electric motorcortex stimulation (CS) was used to directly verify the PG location and indirectly the fiber tract position.


RESULTS
In 11 cases (92%) the prediction of the principal motor pathways' position was correct. In one case of a meningioma, according to PTV, the tumor was falsely localized postcentrally. In the case of a precentral cavernoma, no motor response could be elicited by cortical stimulation.


CONCLUSIONS
Intraoperative PTV on the basis of ADW provides the neurosurgeon with reliable information concerning the position of the principal motor pathways during intracranial procedures as proved with intraoperative electrophysiological testing. The technique has the potential to reduce operative morbidity. PTV is straightforward and can be adapted to other customized neuronavigation devices.
Department of Neurosurgery, University Hospital of the Aachen University (RWTH), Aachen, Germany.
Volker Arnd
VA
Coenen
Timo
T
Krings
Hubertus
H
Axer
Jürgen
J
Weidemann
Heidi
H
Kränzlein
Franz-Josef
FJ
Hans
Armin
A
Thron
Joachim Michael
JM
Gilsbach
Veit
V
Rohde
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016880:Anisotropy; D001932:Brain Neoplasms / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods; D004558:Electric Stimulation; D004594:Electrophysiology; D005260:Female; D006801:Humans; D007432:Intraoperative Period; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000473:pathology* / Q000503:physiopathology* / Q000601:surgery; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011712:Pyramidal Tracts / Q000473:pathology* / Q000503:physiopathology* / Q000601:surgery