Functional magnetic resonance imaging-integrated neuronavigation: correlation between lesion-to-motor cortex distance and outcome.
OBJECTIVE
The integration of functional magnetic resonance imaging (fMRI) data into neuronavigation is a new concept for surgery adjacent to the motor cortex. However, the clinical value remains to be defined. In this study, we investigated the correlation between the lesion-to-fMRI activation distance and the occurrence of a new postoperative deficit.


METHODS
fMRI-integrated "functional" neuronavigation was used for surgery around the motor strip in 54 patients. During standardized paradigms for hand, foot, and tongue movements, echo-planar imaging T2* blood oxygen level-dependent sequences were acquired and processed with BrainVoyager 2000 software (Brain Innovation, Maastricht, The Netherlands). Neuronavigation was performed with the VectorVision(2) system (BrainLAB, Heimstetten, Germany). For outcome analysis, patient age, histological findings, size of lesion, distance to the fMRI areas, preoperative and postoperative Karnofsky index, postoperative motor deficit, and type of resection were analyzed.


RESULTS
In 45 patients, a gross total resection (>95%) was performed, and for 9 lesions (low-grade glioma, 4; glioblastoma, 5), a subtotal resection (80-95%) was achieved. The neurological outcome improved in 16 patients (29.6%), was unchanged in 29 patients (53.7%), and deteriorated in 9 patients (16.7%). Significant predictors of a new neurological deficit were a lesion-to-activation distance of less than 5 mm (P < 0.01) and incomplete resection (P < 0.05).


CONCLUSIONS
fMRI-integrated neuronavigation is a useful concept to assess the risk of a new motor deficit after surgery. Our data suggest that a lesion-to-activation distance of less than 5 mm is associated with a higher risk of neurological deterioration. Within a 10-mm range, cortical stimulation should be performed. For a lesion-to-activation distance of more than 10 mm, a complete resection can be achieved safely. The visualization of fiber tracks is desirable to complete the representation of the motor system.
Krishnan
René
R
Department of Neurosurgery, Johann Wolfgang Goethe University, Frankfurt am Main, Germany. R.Krishnan@em.uni-frankfurt.de
Raabe
Andreas
A
Hattingen
Elke
E
Szelényi
Andrea
A
Yahya
Hilal
H
Hermann
Elvis
E
Zimmermann
Michael
M
Seifert
Volker
V
D000328:Adult; D000368:Aged; D001932:Brain Neoplasms / Q000473:pathology / Q000601:surgery; D020295:Brain Stem Neoplasms / Q000473:pathology / Q000601:surgery; D020785:Central Nervous System Vascular Malformations / Q000601:surgery; D004525:Efferent Pathways / Q000473:pathology / Q000601:surgery; D004806:Ependymoma / Q000473:pathology / Q000601:surgery; D005260:Female; D005909:Glioblastoma / Q000473:pathology / Q000601:surgery; D005910:Glioma / Q000473:pathology / Q000601:surgery; D020786:Hemangioma, Cavernous, Central Nervous System / Q000601:surgery; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008579:Meningioma / Q000473:pathology / Q000601:surgery; D008875:Middle Aged; D038361:Neuronavigation / Q000379:methods*; D011183:Postoperative Complications; D025321:Surgery, Computer-Assisted / Q000379:methods