Tag: White matter tracts

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Quantitative MRI Tractography of White Matter Tracts After Tumor Craniotomy Surgery: Comparative Analysis Between Tubular Retractor and Open Craniotomy Surgery

Operative Neurosurgery 30:525–532, 2026

This study compares quantitative diffusion MRI tractography outcomes after deep-seated brain tumor resections using tubular retraction (TR) versus open craniotomy (OC) with spatula/cottonoid retraction. In a matched cohort of 20 patients, TR achieved comparable extent of resection with improved postoperative fractional and geodesic anisotropy metrics and a greater mean increase in Karnofsky Performance Score.

Methods include pre/postoperative 1.5T DTI, autosegmented tractography of ipsilateral tracts, and statistical comparison of FA, GA, diffusivity metrics, and tract volume. Results suggest TR reduces certain retraction-related white matter distortion without worsening diffusivity markers, supporting TR as a viable technique for deep subcortical lesions with potential functional benefit.

Goal Quantitatively compare cerebral retraction–related white matter tract changes after deep-seated tumor surgery using tubular retraction (TR) vs open craniotomy (OC) with spatula retraction via diffusion MRI tractography metrics.

Design Retrospective matched-pair analysis of 20 patients (10 TR vs 10 OC), matched by tumor size, depth, and age; all surgeries performed by a single surgeon.

Tractography process/metrics Pre- and postoperative DTI tractography (1.5T MRI) autosegmented ipsilateral supratentorial tracts; quantified FA, GA, MD, RD, AD, and tract volume across specified tracts (e.g., corticospinal, arcuate/SLF, ILF, IFOF, fornix, uncinate, optic radiations).

Extent of resection Resection was comparable between groups (TR 90.4% vs OC 94.8%, P = .395).

Functional outcome Change in Karnofsky Performance Score (KPS) favored TR (mean +11 points) vs OC (no change), P = .035.

Key quantitative findings Postoperative FA and GA differed significantly in favor of TR (FA 0.322 TR vs 0.029 OC, P = .011; GA increased in TR 0.441 vs decreased in OC 0.411, P = .012).

Other imaging metrics Postoperative tract volume was higher in TR than OC (14.9 cm³ vs 10.6 cm³, P = .036), while diffusivity metrics (MD, RD, AD) were broadly comparable between cohorts.

Conclusion TR offers a viable approach for deep-seated tumors with similar resection extent while mitigating some components of retraction injury as reflected by quantitative tractography changes and improved KPS.

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Resectability of White Matter Tracts in Patients With Language-Critical Gliomas

Neurosurgery 00:1–9, 2025 (Published Online, October 15, 2025)

Resection of white matter tracts (WMTs) in language-critical glioma surgery robustly predicts permanent postoperative language deficits, particularly when parietal and temporal segments are involved. Frontal lobe WMTs are often safely resectable. Anatomical stratification enhances prediction, supporting data-driven, segment-specific surgical planning.

Resecting language-associated white matter tracts (WMTs) in glioma surgery robustly predicts permanent postoperative language deficits (PLDs).

• Frontal lobe WMT segments (e.g., arcuate fasciculus, IFOF, UF, SLF, FAT) are often resectable without causing PLDs.

• Resections in the temporoparietal junction (TPJ) and middle temporal lobe (MTL) significantly increase the risk of PLDs.

• Anatomically stratifying resections to parietal and temporal tracts improves prediction accuracy for PLDs (PPV increases to 50%).

• Volume of tract resected does not correlate with risk of PLDs; specific tract location is more important.

• Broca area and underlying white matter can often be resected safely, challenging traditional localizationist models.

• Combining imaging data with intraoperative mapping remains essential due to some nonfunctional tract segments leading to low PPV.

• Study limitations include small sample size, operator variability in tractography, and need for multicenter validation.

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Neural and vascular architecture of the septum pellucidum: an anatomical study and considerations for safe endoscopic septum pellucidotomy

J Neurosurg 133:902–911, 2020

The septum pellucidum is a bilateral thin membranous structure representing the border between the frontal horns of the lateral ventricles. Its most examined components are the septal veins due to their surgical importance during endoscopic septum pellucidotomy (ESP), which is a well-accepted method for surgical treatment of unilateral hydrocephalus. It is widely accepted that the septum pellucidum contains nerve fibers as well, but interestingly, no anatomical study has been addressed to its neural components before. The aim of the present study was to identify these elements as well as their relations to the septal veins and to define major landmarks within the ventricular system for neurosurgical use.

METHODS Nine formalin-fixed human cadaveric brains (18 septa pellucida) were involved in this study. A central block containing both septa pellucida was removed and frozen at -30°C for 2 weeks in 7 cases. The fibers of the septum pellucidum and the adjacent areas including the venous elements were dissected under magnification by using homemade wooden spatulas and microsurgical instruments. In 2 cases a histological technique was used to validate the findings of the dissections. The blocks were sliced, embedded in paraffin, cut in 7-μm-thick slices, and then stained as follows: 1) with H & E, 2) with Luxol fast blue combined with cresyl violet, and 3) with Luxol fast blue combined with Sirius red.

RESULTS The septum pellucidum and the subjacent septum verum form the medial wall of the frontal horn of the lateral ventricle. Both structures contain nerve fibers that were organized in 3 groups: 1) the precommissural fibers of the fornix; 2) the inferior fascicle; and 3) the superior fascicle of the septum pellucidum. The area directly rostral to the postcommissural column of the fornix consisted of macroscopically identifiable gray matter corresponding to the septal nuclei. The histological examinations validated the findings of the authors’ fiber dissections.

CONCLUSIONS The nerve elements of the septum pellucidum as well as the subjacent septum verum were identified with fiber dissection and verified with histology for the first time. The septal nuclei located just anterior to the fornix and the precommissural fibers of the fornix should be preserved during ESP. Considering the venous anatomy as well as the neural architecture of the septum pellucidum, the fenestration should ideally be placed above the superior edge of the fornix and preferably dorsal to the interventricular foramen.

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The Dentate Nucleus and Its Projection System in the Human Cerebellum

The Dentate Nucleus and Its Projection System in the Human Cerebellum

Neurosurgery 74:401–425, 2014

Neurosurgical management of cerebellar lesions remains challenging. Thus, it is important to have sound knowledge of the microsurgical anatomy of the cerebellum and dentate nucleus (DN) and to define different types of exposure in a variety of surgical interventions.

OBJECTIVE: To examine the anatomy of the DN from a neurosurgical viewpoint using fiber tracking techniques.

METHODS: Ten formalin-fixed human hemispheres were dissected with the Ludwig and Klingler fiber dissection technique under · 6 to · 40 magnification. Anatomic images were created with 3-dimensional diffusion tensor imaging. The relationships of the DN to tentorium and suboccipital and lateral surfaces of the cerebellum and its spatial positioning relative to different surgical approaches in the cerebellum and fourth ventricle were examined. The fiber tracts terminating at and surrounding the DN were defined.

RESULTS: The DN is at greater risk of being injured in the transvermian and supratonsillar approaches to the cerebellum and fourth ventricle, with lesser risk in the telovelar and subtonsillar approaches. Superior approaches are safer compared with other approaches.

CONCLUSION: The DN represents an important anatomic structure in surgical interventions involving the posterior fossa, particularly in the elderly because of the common occurrence of atrophy-related problems in this age group. Functionally and anatomically, the DN is closely related to the superior and middle cerebellar peduncles. The inferior cerebellar peduncle poses positional risks because it follows an anterior and superior course relative to the DN. The telovelar approach is a safer procedure for interventions involving the pathological lesions of the fourth ventricle floor.

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