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The critical role of different adjuncts in improving the neurological outcome in intrinsic brain lesions affecting eloquent areas is demonstrated by their more diffuse utilization. Neurosurgeons often rely on preoperative and intraoperative diffusion tensor imaging tractography to improve the operative strategy and prognosis. We aimed to identify and validate a diffusion tensor imaging–based classification considering the relationship between the brain lesion and the corticospinal tract to predict a >50% reduction of motor evoked potentials (MEPs) during surgical excision of lesions involving the motor pathways. We included patients consecutively enrolled at our institution between April 2020 and September 2022 with 3 patterns of increasing complexity according to the relationship between the lesion and the corticospinal tract as identified on preoperative diffusion tensor imaging. Outcome measures were >50% reduction in intraoperative MEPs and neurological outcome defined as unchanged, improved, or worsened. The study included 83 patients. A statistically significant linear trend between higher rates of reduction of MEPs and higher classification grades was observed (P = 0.001), with sensitivity 0.60, specificity 0.88, accuracy 0.83, and area under the curve 0.75. Higher grades were associated with worse neurological outcomes (P = 0.02). The classification proved reliable in anticipating reduction in intraoperative MEPs and in predicting neurological outcome. Using this classification in patients undergoing surgery for lesions involving the motor pathways could help in counseling the patient, surgical planning, enhancing teamwork of operating room personnel, and improving the patient's prognosis. [ABSTRACT FROM AUTHOR]

The Subdural Hematoma in the Elderly (SHE) score has been recently developed to assess the 30-day mortality in acute and chronic subdural hematomas in patients >65 years and has shown good reliability. We aimed to validate the SHE score's accuracy to predict 30-day mortality on a homogeneous cohort of patients undergoing surgical chronic subdural hematoma evacuation at our Institution. We also investigated whether the SHE score could reliably predict the occurrence of 30-day chronic subdural hematoma recurrence needing surgery. We included patients from our prospectively collected database from January 2018 to January 2021. Patients with the availability of the following information were enrolled: age, Glasgow Coma Scale score on admission, hematoma volume, medical history, and outcome at 30 days. The SHE score was calculated for each patient, and the association between greater scores and 30-day mortality was investigated and its ability to predict 30-day and disease recurrence. Statistical significance was assessed for P < 0.05. Three hundred twenty-one patients were included. Of them, 40 (12.5%) displayed mortality within 30-day: specifically, 0% of the group of patients with SHE score = 0, 4.3% of SHE score = 1, 14.5% of SHE score = 2, 39.3% of SHE score = 3, and 37.5% of SHE score = 4, with a statistically significant linear trend between greater SHE scores and 30-day mortality rates (P < 0.001, area under the curve 0.75 [0.67–0.82]). No significant association of the SHE score with the risk of recurrence needing surgery was detected (P = 0.4). The SHE score proved helpful in predicting 30-day mortality in patients with chronic subdural hematomas, but no utility was observed to predict disease recurrence. [ABSTRACT FROM AUTHOR]

The presence of peritumorally impaired blood oxygenation-level dependent cerebrovascular reactivity (BOLD-CVR) has been unequivocally demonstrated in patients with diffuse glioma, and may have value to better identify tumor infiltration zone. Since BOLD-CVR does not measure hemodynamic changes directly, we performed additional MR perfusion studies to better characterize the peritumoral hemodynamic environment. Seventeen patients with WHO grade III and IV diffuse glioma underwent high resolution advanced hemodynamic MR imaging including BOLD-CVR and MR perfusion. The obtained multiparametric hemodynamic factors (i.e., regional cerebral blood flow (rCBF), relative cerebral blood volume (rCBV), mean transit time (MTT), time-to-peak (TTP) and BOLD-CVR, were analyzed within 10 concentric expanding 3 mm volumes of interest (VOIs) up to 30 mm from the tumor tissue mask. BOLD-CVR impairment was found within the tumor tissue mask and the peritumoral VOIs up to 21 mm as compared to the contralateral flipped CVR analysis (p<0.05). In the affected hemisphere, we observed positive spatial correlations including all VOIs between BOLD-CVR and rCBV values (r=0.27; p<0.001), rCBF (r=0.42; p<0.001) and a negative correlation between BOLD-CVR and TTP (r=-0.47; p<0.001). Peritumorally impaired BOLD-CVR is associated with concomitant hemodynamic alterations with severity correlating to tumor volume. The distribution of these multiparametric hemodynamic MRI patterns may be considered for future studies characterizing the hemodynamic peritumoral environment, thereby better identifying the extent of tumor infiltration. [ABSTRACT FROM AUTHOR]

Lesions arising or abutting in the posterior half of the third ventricle are approached through established routes to avoid damage of essential brain structures. Occasionally, the features of the lesion require rethinking these traditional routes and tailoring the surgical approach to cause fewer debilitating sequelae to the patient. We introduce a modification of previously described transcortical approaches to lesions of the posterior third ventricle. The technique and possible indications are discussed. Two cases of posterior third ventricle tumors are presented. In both patients, a small posterior fossa and large tentorial veins located along the surgical route, as well as the position of the lesion underneath the internal cerebral veins, encouraged the concept of a novel transoccipital horn approach that was developed to access the tumor with less postoperative deficits. Both lesions were removed with transitory postoperative visual deficits. The transoccipital horn approach is a feasible alternative to other surgical routes to the posterior part of the third ventricle in cases of particularly challenging anatomy and tumor characteristics. It allows reaching the lesion along its major axis, fully exploiting the natural space created by the tumor in its growth and avoiding the internal cerebral veins. [ABSTRACT FROM AUTHOR]

The aim of the present study was to determine the position of the 3 sensory branches of the trigeminal nerve in the preganglionic tract using intraoperative neurophysiological mapping. We included consecutive adult patients who underwent neurosurgical treatment of cerebellopontine angle lesions. The trigeminal nerve was antidromically stimulated at 3 sites along its circumference with different stimulus intensities at a distance of ≤1 cm from the brainstem. The sensory nerve action potentials (SNAPs) were recorded from each main trigeminal branch (V1 [ophthalmic branch], V2 [maxillary branch], and V3 [mandibular branch]). We analyzed 13 patients. The stimulation points at which we obtained the greatest number of congruous and exclusive SNAPs (SNAPs only on the stimulated branch) was the stimulation point for V3 (20.7%). The stimulation intensity at which we obtained the highest number of congruent and exclusive SNAPs with the stimulated branch was 0.5 mA. Using our recording conditions, trigeminal stimulation is a reliable technique for mapping the V3 and V1 branches using an intensity not exceeding 0.5. However, reliable identification of the fibers of V2 is more difficult. Stimulation of the trigeminal nerve can be a reliable technique to identify the V3 and V1 branches if rhizotomy of these branches is necessary. [ABSTRACT FROM AUTHOR]

The role of visual evoked potentials (VEPs) monitoring during neurosurgical procedure in patient remains unclear. The purpose of our study was to determine the feasibility of intraoperative VEP recording using a strip cortical electrode during surgical resection of intracranial lesions. In this prospective, monocentric, observational study, we enrolled consecutive patients undergoing neurosurgical procedure for intracranial lesions. After dural opening, a cortical strip was positioned on the lateral occipital surface. Flash VEPs were continuously recorded using both subdermal corkscrew electrodes and strip electrodes. An electroretinogram was also recorded to guarantee delivery of adequate flash stimuli to the retina. We included 10 patients affected by different intracranial lesions. Flash VEPs were recorded using subdermal corkscrew electrodes in all patients except 1 in whom they were never identified during the recording. Flash VEPs were recorded using strip electrodes in all patients and showed a polyphasic morphology with a significantly larger amplitude compared with that of flash VEPs measured using subdermal corkscrew electrodes. No patient reported worsened postoperative vision and a >50% decrease in the VEPs amplitude was never registered. We have reported for the first time in the literature that VEP monitoring during a neurosurgical procedure is feasible via a cortical strip located on the occipital surface. The technique demonstrated greater stability and a larger amplitude compared with recordings with scalp electrodes, facilitating identification of any changes. Studies with more patients are needed to assess the clinical reliability of the technique. [ABSTRACT FROM AUTHOR]