Tag: precuneus

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The Case Series of Contralateral Interhemispheric Transfalcine Approach to Medial Parietooccipital Pathologies: Surgical Technique and Results

Operative Neurosurgery 29:495–504, 2025

This retrospective case series evaluates the contralateral interhemispheric transfalcine approach (PITTA) for medial parietooccipital and peritrigonal brain lesions. The technique offers improved visualization and minimized brain manipulation, with acceptable complication rates, but requires careful venous management and is best suited for experienced neurosurgeons.

The contralateral interhemispheric transfalcine (PITTA) approach is used for challenging medial parietooccipital and peritrigonal brain lesions.

• A retrospective study of 19 cases showed PITTA was applied to vascular lesions (AVMs) and tumors (glioblastomas, meningiomas, metastases, pilocytic astrocytoma).

• The approach improves visualization and reduces manipulation of eloquent cortex and white matter compared to traditional ipsilateral approaches.

• Mean surgery time was about 4 hours 15 minutes, and most patients had temporary neurological deficits that resolved within days.

• Superior sagittal sinus injury and small vein sacrifice occurred in a few cases but were managed without lasting complications.

• No new visual deficits or permanent ipsilateral parietal lobe injuries were observed; most complications were minor and transient.

• PITTA is technically demanding and best suited for experienced neurosurgeons; careful preoperative planning and venous anatomy assessment are critical.

• The study concludes PITTA is a valuable option for selected cases, but larger prospective studies are needed to compare it with standard approaches.

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Precuneal gliomas promote behaviorally relevant remodeling of the functional connectome

J Neurosurg 138:1531–1541, 2023

The precuneus hosts one of the most complex patterns of functional connectivity in the human brain. However, due to the extreme rarity of neurological lesions specifically targeting this structure, it remains unknown how focal damage to the precuneus may impact resting-state functional connectivity (rsFC) at the brainwide level. The aim of this study was to investigate glioma-induced rsFC modulations and to identify patterns of rsFC remodeling that accounted for the maintenance of cognitive performance after awake-guided surgical excision.

METHODS In a unique series of patients with IDH1-mutated low-grade gliomas (LGGs) infiltrating the precuneus who were treated at a single neurosurgical center (Montpellier University Medical Center, 2014–2021), the authors gauged the dynamic modulations induced by tumors on rsFC in comparison with healthy participants. All patients received a preoperative resting-state functional MRI and underwent operation guided by awake cognitive mapping. Connectome multivariate pattern analysis (MVPA), seed-network analysis, and graph theoretical analysis were conducted and correlated to executive neurocognitive scores (i.e., phonological and semantic fluencies, Trail-Making Test [TMT] parts A and B) obtained 3 months after surgery.

RESULTS Seventeen patients with focal precuneal infiltration were selected (mean age 38.1 ± 11.2 years) and matched to 17 healthy participants (mean age 40.5 ± 10.4 years) for rsFC analyses. All patients underwent awake cognitive mapping, allowing total resection (n = 3) or subtotal resection (n = 14), with a mean extent of resection of 90.6% ± 7.3%. Using MVPA (cluster threshold: p–false discovery rate corrected < 0.05, voxel threshold: p-uncorrected < 0.001), remote hotspots with significant rsFC changes were identified, including both insulas, the anterior cingulate cortex, superior sensorimotor cortices, and both frontal eye fields. Further seed-network analyses captured 2 patterns of between-network redistribution especially involving hyperconnectivity between the salience, visual, and dorsal attentional networks. Finally, the global efficiency of the salience-visual-dorsal attentional networks was strongly and positively correlated to 3-month postsurgical scores (n = 15) for phonological fluency (r 15 = 0.74, p = 0.0027); TMT-A (r 15 = 0.65, p = 0.012); TMTB (r 15 = 0.70, p = 0.005); and TMT-B-A (r 15 = 0.62, p = 0.018).

CONCLUSIONS In patients with LGGs infiltrating the precuneus, remote and distributed functional connectivity modulations in the preoperative setting are associated with better maintenance of cognitive performance after surgery. These findings provide a new vision of the mechanistic principles underlying neural plasticity and cognitive compensation in patients with LGGs.

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