White matter tractography for neurosurgical planning: A topography-based review of the current state of the art

Abstract

We perform a review of the literature in the field of white matter tractography for neurosurgical planning, focusing on those works where tractography was correlated with clinical information such as patient outcome, clinical functional testing, or electro-cortical stimulation. We organize the review by anatomical location in the brain and by surgical procedure, including both supratentorial and infratentorial pathologies, and excluding spinal cord applications. Where possible, we discuss implications of tractography for clinical care, as well as clinically relevant technical considerations regarding the tractography methods. We find that tractography is a valuable tool in variable situations in modern neurosurgery. Our survey of recent reports demonstrates multiple potentially successful applications of white matter tractography in neurosurgery, with progress towards overcoming clinical challenges of standardization and interpretation.

Keywords: DBS, Deep brain stimulation; DES, Direct electrical stimulation; DTT, Direct tract targeting; FA, Fractional anisotropy; FN, Facial nerve; Neurosurgical planning; Review; Tractography; WMT, White matter tractography; White matter.

Fig. 1

Illustration of the anatomical subdivision structuring this report.

Fig. 2

Pre-surgical plan of right handed 18 y.o. patient presenting with left frontal glioblastoma. White matter tractography allowed to assess the relationships between the tumor (orange) and eloquent tracts (green: arcuate fasciculus, red: uncinate fasciculus, blue: corticospinal tract). These results are valuable for planning the safest surgical route and resection. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)

Fig. 3

Tractography efficacy patterns in a bilateral DBS of the sub thalamic nucleus in a Parkinson's disease patient. A: Patient underwent bilateral electrode implantation; tremor control was better in the patient's right side. Post-operative imaging confirmed that the right-side electrode location was slightly posterior to the selected target (blue). The connectivity patterns obtained from stimulation sites were asymmetric with more superior frontal gyrus connectivity in the left hemisphere. B: After five years, patient underwent bilateral re-implantation; old and new stimulation sites were superimposed on the left side (blue/red). The new right side stimulation site was anterior to the old site (blue/red). Bilateral tremor control was achieved by the new surgery. New tractography patterns became more symmetrical (yellow: old tracts). (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)