Gompel, Jamie J. Van

Understanding motor representation in the human brain requires mapping beyond the primary motor cortex, into the distributed networks that coordinate complex movements. The insular cortex, a multifunctional hub buried within the Sylvian fissure, has been implicated in motor control through clinical observations and neuroimaging. Yet its precise relation to primary sensorimotor processing remains one of the least understood aspects of motor neurophysiology. To address this gap, we quantified electrophysiological changes from implanted depth electrodes in patients performing simple movement tasks combined with single-pulse electrical stimulation (SPES) to map effective connectivity. The movement data reveal somatotopically specific representation bilaterally, as well as intereffector regions that are active for different movement types. Hand representation is centered along the contralateral ventral aspect of the middle and posterior short gyri bilaterally, while tongue/mouth tuned sites cluster in the dorsal posterior short gyrus and the dorsal long gyri. Insular activity temporally follows the primary motor cortex (M1) and precedes movement onset. SPES revealed somatotopically specific connectivity between corresponding sites in M1 and insula (hand-to-hand, tongue-to-tongue) and between bilateral insulae. These observations establish that somatotopy is a conserved property of distributed motor control incorporating the insular representations and connectivity.

Abstract This review aims to update recent advancements in the management and treatment of olfactory neuroblastoma (ONB) based on discussions and topics highlighted during the 2024 North American Skull Base Society session “Literature Review: What's New in Olfactory Neuroblastoma?” A systematic review was conducted using PubMed/MEDLINE, focusing on relevant studies published between January 2022 and June 2024. Data were organized into themes: prognostication and staging, surgical concepts, biomarkers/genomics, imaging, syndrome of inappropriate antidiuretic hormone release and hyponatremia, chemotherapy, and radiotherapy. Out of 289 initial records, 46 studies met eligibility criteria. Key findings include the proposed integration of Hyams grading and dural infiltration with traditional staging for better prognostic accuracy, a shift toward less invasive surgical techniques while maintaining clear resection margins, and the identification of biomarkers for improved diagnosis and targeted therapy. Advanced imaging modalities like DOTA-peptide tomography (positron emission tomography–computed tomography/magnetic resonance imaging) were highlighted for their diagnostic value. Variability in induction chemotherapy outcomes underscores the need for personalized treatment plans, and new radiotherapy techniques offer promising results with improving morbidity. Recent advancements in ONB management have enhanced prognostic accuracy, molecular diagnostics, imaging techniques, and treatment outcomes. Continuous research is necessary to optimize these strategies and further improve patient survival and quality of life.

OBJECTIVE Epilepsy affects nearly 50 million individuals worldwide, with one-third of cases resistant to antiseizure medications. For these patients, surgical intervention offers a potential path to seizure freedom. While resective surgery has been the gold standard, laser interstitial thermal therapy (LITT) has emerged as a minimally invasive alternative. The aim of this study was to evaluate the efficacy and safety of LITT versus resective surgery in patients with nontumoral epilepsy. METHODS A systematic review and meta-analysis were conducted using PubMed, Embase, and Scopus, including studies comparing seizure freedom rates, complications, and procedural outcomes between LITT and open surgery in nontumoral epilepsy. Eleven studies met the inclusion criteria, comprising 389 LITT and 557 open surgery patients with varying epilepsy etiologies, including temporal lobe epilepsy, focal cortical dysplasia, and tuberous sclerosis. Statistical analysis was performed using a random-effects model to assess seizure freedom, complications, and reoperation rates. RESULTS Open surgery demonstrated higher rates of complete seizure freedom, although not reaching significance (68.1% vs 53.7%, RR 0.81, p = 0.07). This outcome was sensitive to influential analysis and reached significance in the epileptogenic zone–directed resection subgroup analysis. Although adequate seizure freedom was comparable between the groups (LITT: 63.0% vs open: 74.0%, RR 0.90, p = 0.11), the open surgery group had higher rates of control in the pediatric and non–temporal lobe epilepsy subgroups. Complication rates were significantly higher in the open surgery group (30.0% vs 18.3%, RR 0.55, p < 0.01). LITT patients had significantly shorter hospital stays (3.4 vs 6.8 days, standardized mean difference −0.93, p < 0.01). Reoperation rates were comparable between groups (13.1% for LITT vs 13.4%, RR 1.59, p = 0.26). CONCLUSIONS While LITT offers a less invasive approach with reduced hospitalization and morbidity, open surgery remains slightly superior in achieving long-term seizure freedom. Patient selection remains critical, and further studies are needed to refine decision-making criteria based on epilepsy subtype and lesion characteristics.

OBJECTIVE Early discharge following uncomplicated endonasal resection of pituitary adenoma has been described as safe and feasible. Discharge on postoperative day (POD) 1 is not a widely implemented practice in the United States. This study aimed to evaluate the safety of routine POD1 discharges by assessing postoperative unplanned medical care rates compared with those of patients discharged on POD 2 or later (POD2+). The secondary endpoint was to identify predictors of delayed discharge in the POD2+ cohort. METHODS A retrospective database review of the medical records of 534 patients who underwent endonasal resection of pituitary adenoma at the Mayo Clinic was performed. Relevant demographics, tumor characteristics, and perioperative metrics were abstracted from the medical record, including intraoperative CSF leakage, postoperative complications, emergency department visits, or inpatient readmissions within 30 days. Descriptive, univariate, and multivariate analyses were performed. RESULTS In comparison to 422 (79%) patients discharged on POD1, 112 (21%) patients discharged on POD2+ had a higher unplanned medical care rate (13% vs 5.5%, p = 0.019). There were significantly more men in the POD1 group (48%) than in the POD2+ group (37%) (p < 0.04). The most common reasons for POD1 unplanned care were endocrine dysfunction (2.4%), split evenly between syndrome of inappropriate antidiuretic hormone and adrenal insufficiency, whereas the most frequent reason in the POD2+ cohort was medical (0.06%). Univariate analyses indicated that female sex, higher BMI, intensive care unit (ICU) admission, obstructive sleep apnea, continuous positive airway pressure dependence, intraoperative CSF leakage, and diabetes insipidus (DI) increased the likelihood of POD2+ discharge. The reduced logistic regression model demonstrated a higher likelihood of POD2+ discharge with older age, ICU admission, intraoperative CSF leakage, and DI (p < 0.001). Common factors contributing to discharge after POD1 included endocrine (n = 66, 35%) and/or medical (n = 65, 34%) reasons. CONCLUSIONS Routine patient discharge on POD1 following uncomplicated endonasal resection of pituitary adenoma is a safe practice, as evidenced by the significantly lower rates of unplanned medical care and complications compared with those of patients discharged on POD2 or later. Delayed discharge was associated with older age, ICU admission, intraoperative CSF leakage, and DI. The most frequent reasons for POD1 readmission were endocrine versus medical reasons for POD2+. Preoperative identification of risk factors for delayed discharge and preemptive management of endocrine and medical complications may reduce the length of stay and return to medical care.

OBJECTIVE The objective of this study was to describe the long-term efficacy of single-fraction stereotactic radiosurgery (SRS) for the primary treatment of sporadic vestibular schwannoma. METHODS Adult (≥ 18 years of age) patients with sporadic vestibular schwannoma who underwent SRS from 2000 through 2022 were included. RESULTS A total of 749 patients met inclusion criteria, the majority (n = 566, 76%) of whom had tumors extending into the cerebellopontine angle at SRS. The median patient age at SRS was 62 years, half (50%) of the patients were women, and 744 (99%) exhibited House-Brackmann grade I facial nerve function at SRS. A total of 42 patients experienced radiosurgical failure and underwent salvage treatment; the median duration of follow-up for the patients who did not undergo salvage treatment was 7.0 years. Overall tumor control rates (95% CI, number still at risk) at 1, 3, 5, 10, and 15 years after SRS were 100% (100%–100%, 718), 98% (97%–99%, 589), 96% (94%–97%, 464), 92% (90%–95%, 258), and 91% (89%–94%, 125), respectively. Patient age (hazard ratio [HR] for a 10-year increase of 0.92, 95% CI 0.71–1.19; p = 0.5), presence of a macrocystic tumor (HR 0.59, 95% CI 0.14–2.46; p = 0.5), and treated tumor volume (HR for a 1-cm 3 increase of 1.02, 95% CI 0.88–1.18; p = 0.8) were not significantly associated with the risk of salvage. Three distinct post-SRS tumor behavior patterns were observed, with 13% of patients demonstrating tumor pseudoprogression, all but 4 of whom demonstrated pseudoprogression by year 5 post-SRS. CONCLUSIONS SRS demonstrates durable tumor control through 15 years of follow-up in most patients (91%); however, a minority are found to still experience SRS failure even beyond 10 years of surveillance. Although occurring in only a minority of patients, tumor pseudoprogression can be evident out to 5 years or longer post-SRS.

OBJECTIVE Wait-and-scan surveillance is now commonly employed for initial management of small- and medium-sized vestibular schwannomas. Although small differences in tumor size are unlikely to impact outcomes significantly, treatment with either radiosurgery or microsurgery is usually recommended following radiological detection of tumor growth. The objective of the current study was to identify potential inflection points in vestibular schwannoma tumor size, where the risks of treatment with single-fraction stereotactic radiosurgery (SRS) accelerate to inform timing of intervention. METHODS Adult (≥ 18 years old) patients with sporadic vestibular schwannoma who underwent SRS from 2000 through 2022 were included. RESULTS A total of 749 patients with a median age at SRS of 62 years were studied, the majority (n = 566 [76%]) of whom had tumors extending into the cerebellopontine angle (CPA) at SRS. The optimal tumor size cut point to predict SRS failure and need for salvage treatment was 4 mm or more of CPA extension (c-index 0.59, HR 3.60, p = 0.01). The optimal tumor size cut point to predict the outcome of facial nerve paresis was 13 mm or more of CPA extension, resulting in a c-index of 0.63 (HR 2.88, p = 0.01). Among patients with at least 3 months of surveillance before SRS, those with a tumor growth rate ≥ 2.5 mm/year were more likely to undergo salvage treatment than those with a growth rate < 2.5 mm/year, although this difference did not achieve statistical significance (HR 1.82, p = 0.18). CONCLUSIONS The risk of SRS failure requiring salvage treatment and the risk of post-SRS facial nerve paralysis increase at sizes of approximately 4 and 13 mm extension into the CPA, respectively, providing a size threshold anchor to help guide treatment decision-making regarding timing of SRS. Furthermore, rapid tumor growth during the initial wait-and-scan period may be associated with an increased risk of radiosurgical failure, which may influence choice of treatment.

OBJECTIVE Deep brain stimulation (DBS) is emerging as an additional surgical option for refractory, multifocal epilepsy. Four-lead DBS systems can be used when seizure onset is poorly localized, generalized, or involves multiple targetable circuits. The goal of this study was to assess preliminary outcomes and complication rates in 4-lead DBS systems for treating epilepsy. METHODS A consecutive series of 32 patients with 4-lead DBS implants who had at least 6 months of follow-up was reviewed, and demographics, outcomes, and complications were abstracted. RESULTS Thirty-two patients implanted with 4 DBS leads (including off-label use) were included. The median age at surgery was 28.5 years, the median age at epilepsy diagnosis was 7.5 years, and 18 patients (56%) were women. The median epilepsy duration prior to implantation was 21 years. The most common seizure localization was frontotemporal (53%), followed by generalized (28%) and parietoccipital (13%). Prior vagus nerve stimulation had been trialed in 20 patients (63%), and an invasive stereotactic EEG recording was performed in 17 patients (59%). Eight patients had prior epilepsy surgery (25%). DBS targets included the anterior thalamic nucleus in combination with the centromedian thalamic nucleus, hippocampus, pulvinar nucleus, cingulate, insula, and globus pallidus. The median surgical duration was 5 hours 22 minutes, with a median operating room time of 8 hours 21 minutes. The median postoperative follow-up was 27 (interquartile range 17–41) months. Three patients experienced transient neurological deficits and 2 patients required intraoperative lead repositioning. There were no infections or hemorrhages. Most patients benefited from stimulation (22% Engel class I, 22% class II, 28% class III, and 28% class IV). The median patient-reported seizure reduction rate was 70%, with a responder rate of 72%. One patient elected to have the system explanted. CONCLUSIONS Four-lead DBS is safe and can achieve meaningful improvement in challenging cases of multifocal epilepsy with a low complication rate.

Abstract Context Evidence on the evolution of cardiometabolic comorbidities following surgical remission of hypercortisolism is scarce. Objective To determine the impact of surgical remission on cardiometabolic comorbidities in patients with endogenous hypercortisolism and to identify factors associated with cardiometabolic improvement. Methods Prospective single-center cohort study (2019-2025) of adults with Cushing syndrome (CS) or mild autonomous cortisol secretion (MACS) with surgical remission of hypercortisolism. Outcomes included (1) changes in severity of hypertension, diabetes mellitus (DM), hyperlipidemia, and obesity between baseline, 3, and 12 months postremission and (2) factors associated with improvement in comorbidities. Results Among 357 patients (49% MACS, 36% pituitary CS, 10% adrenal CS, 5% ectopic CS; median age 53 years [interquartile range 42-62]; 81% women), 336 (94%) had hypertension, 241 (68%) had obesity, and 122 (35%) had DM. At a median of 12 months postsurgery, improvement in hypertension occurred in 70% (90/128) of patients with CS and 51% (60/117) of patients with MACS, DM in 90% (46/51) patients with CS and 37% (13/35) patients with MACS, and obesity in 79% (77/97) patients with CS and 20% (14/71) patients with MACS. In a multivariable analysis, higher baseline biochemical severity scores were associated with improvement in hypertension [odds ratio (OR) 1.3, 95% confidence interval (CI) 1.1-1.5), DM (OR 2.5, 95% CI 1.7-4.1), and obesity (OR 1.5, 95% CI 1.2-1.8) at a median of 12 months postremission of hypercortisolism. Conclusion Postsurgical improvement of cardiometabolic comorbidities was observed in both patients with CS and MACS. Higher baseline biochemical severity scores were associated with higher postremission improvement in comorbidities.