Journal of neurosurgery最新文献

Objective: Radiologically, Chiari malformation type I (CM-I) is characterized by cerebellar tonsil herniation of at least 5 mm through the foramen magnum. In symptomatic cases, posterior fossa decompression (PFD) surgery is often performed and improves symptoms in approximately 75% of patients. However, the surgery involves risks, and identifying which candidates will benefit from surgery is important. It has previously been shown that the amount of tonsillar descent does not correlate with symptom severity or surgical outcomes. The authors hypothesized that using advanced neuroimaging methods to directly measure CSF flow and brain motion will give insights regarding which patients have the greatest likelihood of cerebral dynamic improvements from surgery.

Methods: Here, the authors evaluated 108 CM-I patients (age 19-70 years), 61 of whom underwent PFD surgery. The authors used phase-contrast MRI to measure CSF flow/stroke volume and cine displacement encoding with stimulated echoes (DENSE) imaging to measure brain motion, with a goal to predict postsurgical cerebral dynamic improvements from presurgical images.

Results: The authors found that CSF stroke volume increased after PFD surgery by 28.9% (p = 0.014), brainstem motion decreased after surgery by 17.3% (p = 0.002), and cerebellum motion decreased 45.2% (p < 0.001). Notably, the amount of CSF flow increase after surgery had no relationship to tonsillar descent (R = 0.059, p = 0.767) but did relate to the amount of presurgical CSF flow (R = -0.518, p = 0.005). Likewise, improvements to brain motion were better predicted by the amount of presurgical motion (brainstem, R = -0.638, p < 0.001; cerebellum, R = -0.878, p < 0.001) than by tonsillar descent (brainstem, R = -0.312, p = 0.093; cerebellum, R = -0.620, p < 0.001).

Conclusions: Here, the authors found that presurgical measures of cerebral dynamics were more descriptive of improvements to CSF flow and brain motion after PFD surgery than the conventional measure of presurgical tonsillar descent. These expanded quantitative assessments to determine which patients may benefit from surgery could improve the overall quality of patient care.

Objective: Pulsed radiofrequency (PRF) combined with low-temperature continuous radiofrequency (CRF) might be a novel technique for relieving trigeminal neuralgia (TN). This study aimed to evaluate the efficacy and safety of high-voltage PRF combined with low-temperature CRF in primary TN.

Methods: This randomized controlled trial was performed between December 2, 2020, and October 26, 2022. Eligible patients with TN were randomly assigned at a 1:1 ratio to receive either PRF with a voltage of 70 V at 42°C for 600 seconds followed by CRF at 60°C for 270 seconds (PRF+CRF group) or PRF with a voltage of 70 V at 42°C for 600 seconds (PRF group). The primary outcome was the response rate to treatment after 12 months. The secondary outcomes were the proportion of responders at 1 day, 1 week, 2 weeks, 1 month, 2 months, 3 months, and 6 months following the procedure and the 11-point numeric rating scale (NRS) scores at 1 day, 1 week, 2 weeks, 1 month, 2 months, 3 months, 6 months, and 12 months following the procedure. Adverse events associated with surgery were also observed.

Results: A total of 169 patients with TN were screened, and 146 patients were randomized. The groups were well balanced across baseline characteristics. The percentage of responders at 12 months after surgery was significantly greater in the PRF+CRF group compared with the PRF group (83.6% [61/73] vs 67.1% [49/73], risk ratio 1.2 [95% CI 1.0-1.5], absolute difference 16.5%; p = 0.021). There was a higher proportion of responders after 1 day, 1 week, 2 weeks, 1 month, 2 months, 3 months, and 6 months (ratio difference 16.5%, 35.6%, 16.4%, 12.3%, 12.3%, 12.3%, and 15.1%, respectively; all p < 0.05). Moreover, lower NRS scores were observed in the PRF+CRF group at 1 day, 1 week, 2 weeks, 1 month, 2 months, 3 months, 6 months, and 12 months following the procedure (all p < 0.05). Postoperative facial numbness scores were higher in the PRF+CRF group at 1 day, 1 week, 2 weeks, 1 month, and 2 months (all p < 0.05). Overall, 5.5% of patients in the PRF+CRF group and no patients in the PRF group reported masseter muscle weakening. No other complications, such as anesthesia dolorosa and corneal anesthesia, were observed in either group.

Conclusions: High-voltage PRF combined with low-temperature (60°C) CRF could provide a significant improvement compared with high-voltage PRF alone. Clinical trial registration no.: NCT04174443 (ClinicalTrials.gov).

Objective: Growing evidence suggests that venous outflow obstruction from venous sinus stenosis (VSS) may lead to increased intracranial pressure (ICP) in patients with idiopathic intracranial hypertension (IIH). There is a paucity of evidence examining clinical predictors of elevated cerebral venous pressure gradient (CVPG) from VSS in patients with IIH. In this study, the authors examined predictors of elevated CVPG, determined the sensitivity and specificity of common presenting symptoms of IIH, and identified the optimal opening pressure threshold on lumbar puncture (LP) to determine which patients should undergo venous manometry (VM).

Methods: Patient demographics, presenting symptoms, complications, and opening pressure on LP were collected. Venous pressure gradient across a stenotic dural venous sinus and maximum venous pressure values were recorded from cerebral venograms. VM was considered positive when the CVPG was ≥ 8 mm Hg between two contiguous segments of a dural venous sinus. Sensitivity, specificity, and multivariable logistic regression analysis was performed.

Results: The predominant patient population was young (mean age 38.9 years), obese (BMI ≥ 30; 83.8%), and female (95.0%). Sensitivity and specificity for papilledema were 74% and 70% (area under the curve [AUC] 0.71, 95% CI 0.63-0.80), and 70% and 63% (AUC 0.66, 95% CI 0.57-0.75) for pulsatile tinnitus. Vision changes demonstrated a sensitivity of 80% and specificity of 50% (AUC 0.63, 95% CI 0.54-0.72). VSS seen on magnetic resonance venography (MRV) demonstrated a sensitivity of 90% and specificity of 53% (AUC 0.71, 95% CI 0.63-0.79). Youden's index analysis identified an opening pressure ≥ 25 cm H2O on LP (AUC 0.72, 95% CI 0.60-0.83) as an optimal threshold for predicting elevated CVPG.

Conclusions: Predictors of elevated CVPG on VM include childbearing age, African American race, papilledema, pulsatile tinnitus, obesity (BMI ≥ 30), focal VSS with unilateral dominance in venous drainage seen on MRV, or an opening pressure on LP ≥ 25 cm H2O.

Objective: Preoperative workup of trigeminal neuralgia (TN) consists of identification of neurovascular features on MRI. In this study, the authors apply and evaluate the performance of deep learning models for segmentation of the trigeminal nerve and surrounding vasculature to quantify anatomical features of the nerve and vessels.

Methods: Six U-Net-based neural networks, each with a different encoder backbone, were trained to label constructive interference in steady-state MRI voxels as nerve, vasculature, or background. A retrospective dataset of 50 TN patients at the authors' institution who underwent preoperative high-resolution MRI in 2022 was utilized to train and test the models. Performance was measured by the Dice coefficient and intersection over union (IoU) metrics. Anatomical characteristics, such as surface area of neurovascular contact and distance to the contact point, were computed and compared between the predicted and ground truth segmentations.

Results: Of the evaluated models, the best performing was U-Net with an SE-ResNet50 backbone (Dice score = 0.775 ± 0.015, IoU score = 0.681 ± 0.015). When the SE-ResNet50 backbone was used, the average surface area of neurovascular contact in the testing dataset was 6.90 mm2, which was not significantly different from the surface area calculated from manual segmentation (p = 0.83). The average calculated distance from the brainstem to the contact point was 4.34 mm, which was also not significantly different from manual segmentation (p = 0.29).

Conclusions: U-Net-based neural networks perform well for segmenting trigeminal nerve and vessels from preoperative MRI volumes. This technology enables the development of quantitative and objective metrics for radiographic evaluation of TN.

Objective: Essential tremor (ET) is a prevalent movement disorder that also includes nonmotor symptoms such as anxiety, depression, and cognitive impairment. Deep brain stimulation (DBS) is an established treatment for ET, yet its impact on nonmotor symptoms remains unclear. This study aims to describe neuropsychological outcomes following ventral intermediate nucleus (VIM) DBS in a large cohort of patients with ET and identify factors associated with changes in depression and cognitive function.

Methods: A retrospective cohort study of patients who had undergone VIM DBS was performed. Inclusion criteria were ET diagnosis, surgery between October 2007 and March 2020, and available pre- and post-DBS neuropsychological testing results. Neuropsychological measures included the Beck Depression Inventory-II (BDI-II), Beck Anxiety Inventory (BAI), and cognitive measures assessing attention, executive function, language, memory, and visuospatial function. Post-DBS tremor improvement was graded, and active electrode coordinates and stimulation parameters were identified. Statistical analyses included descriptive statistics, t-tests to compare pre- and postoperative scores at the group level, and one-way analysis of variance to compare variables among patients who improved, were stable, or worsened in psychiatric and cognitive characteristics after DBS.

Results: One hundred thirty-nine patients met the study inclusion criteria. BDI-II scores significantly decreased postoperatively (9.82 ± 6.77 vs 8.29 ± 6.18, p < 0.001, Cohen's d = 0.176), whereas BAI scores remained unchanged. Both language (p = 0.003, Cohen's d = 0.259) and memory (p < 0.001, Cohen's d = 0.336) domains showed statistically significant small-magnitude declines following surgery, whereas attention, executive function, and visuospatial function were unchanged. Patients with improved depression (14.3%) following VIM DBS had significantly higher BDI-II scores preoperatively (p < 0.001, ω2 = 0.226). Patients with worsened language (18.7%) had higher preoperative language scores (p < 0.001, ω2 = 0.058). Patients with worsened memory (15.1%) had higher BAI scores preoperatively (p = 0.002, ω2 = 0.079). Preoperative scores were similar between patients with improved and worsened overall cognition postsurgery. Patients with improved overall cognition had improvements in attention, language, and visuospatial function.

Conclusions: VIM DBS for ET did not result in large-magnitude neuropsychological changes. There were statistically significant, though likely not clinically meaningful, small-magnitude improvements in depression and worsening in language and memory scores. Associations were found between multiple preoperative mood and cognitive scores and post-DBS neuropsychological changes. These findings can help inform clinical decision-making and patient counseling for DBS.

Objective: Periventricular nodular heterotopia (PVNH) is a malformation of cortical development with high rates of epilepsy. The extent to which nodules participate in normal cerebral functions in addition to pathological processes is unclear. The authors assessed the functional utility (i.e., cognitive impacts) of surgically ablated epileptogenic PVNH tissue via comprehensive neuropsychological testing.

Methods: The sample included 32 patients with PVNH who underwent presurgical neuropsychological evaluation and a subsample of 16 patients who underwent MR-guided laser interstitial thermal therapy (MRgLITT) of nodules, with postsurgical neuropsychological testing. In 11 patients in whom intracranial recordings were performed, reading and naming tasks were tested to determine if there was task-related activation within the nodules. Postoperative changes were assessed at the domain level and across individual tests by using reliable change indices, with consideration of spatial distribution and hemisphere of surgery as potential modifiers of postoperative change.

Results: Task-related activation during reading or naming was seen in 53% of electrodes localized within nodules that were later ablated; however, no related postsurgical language impacts were observed. No significant declines occurred following MRgLITT in any domain level z-scores. For single tests, the authors found substantial evidence in favor of the null hypothesis in 18/21 tests. Significant decline was seen only in spatial learning. A substantial association with laterality was identified in the perceptual reasoning index.

Conclusions: The functionality of PVNH tissue was evaluated by direct recordings and changes in cognitive assessments following MRgLITT ablation of epileptogenic nodules. Despite language-related activity seen in these nodules, no pattern of change was observed within any cognitive domain. The only significant decline observed was in spatial learning, whereas perceptual reasoning improved for individuals with surgery in the nondominant hemisphere. These results offer strong evidence against the role of epileptogenic PVNH in cognitive functions. This work speaks to the need for caution in assigning causality to activations seen in functional imaging without evidence from lesional methods.