Faculty Bibliography

BACKGROUND AND OBJECTIVES/OBJECTIVE:Normal pressure hydrocephalus (NPH) is characterized by the classic triad of cognitive decline, gait instability, and urinary incontinence in the setting of ventriculomegaly with normal intracranial pressure. Cerebrospinal fluid diversion is the current standard treatment, yet it carries a risk of overdrainage, resulting in subdural hematoma or hygroma. Different valves have been developed to mitigate this risk, yet consensus remains unclear regarding optimal valve for NPH. METHODS:We performed a retrospective cohort study on all patients with NPH who underwent cerebrospinal fluid shunting or revision between January 2014 and September 2025 at our institution. Demographic, clinical, and radiological data were collected from the electronic health record. Kaplan-Meier survival analysis, univariate logistic regression, and multivariate modeling were used to identify predictors of subdural collections and the need for surgical treatment. RESULTS:Since our change in practice from the Integra NPH Low Flow Valve (Low Flow OSV) to other valves in 2022, we observed a rise in symptomatic subdural collections. Programmable valves were associated with a markedly increased 1-year risk of both subdural collection formation and need for surgical intervention compared with the Low Flow OSV. Overall, Certas and Strata valves demonstrated higher rates of subdural collections requiring surgery than the Low Flow OSV (14.6% vs 2.1%, P < .001; 10.5% vs 2.1%, P = .005, respectively). On multivariate analysis, both the Strata and Certas valves were independently associated with increased odds of developing any subdural collection and necessitating surgery. Vascular disease and dual antiplatelet therapy also increased risk. CONCLUSION/CONCLUSIONS:In this large single-center cohort study, programmable valves, specifically the Certas and Strata, were associated with an increased rate and severity of subdural collections compared with the Low Flow OSV. The use of low-flow designs may mitigate complications for the NPH population, and the use of lower programmable valve settings should be carefully considered.

[This corrects the article DOI: 10.3389/fonc.2023.1132777.].

INTRODUCTION/UNASSIGNED:Brain metastases are the most common intracranial tumor diagnosed in adults. In patients treated with stereotactic radiosurgery, the incidence of post-treatment radionecrosis appears to be rising, which has been attributed to improved patient survival as well as novel systemic treatments. The impacts of concomitant immunotherapy and the interval between diagnosis and treatment on patient outcomes are unclear. METHODS/UNASSIGNED:This single institution, retrospective study consisted of patients who received single or multi-fraction stereotactic radiosurgery for intact brain metastases. Exclusion criteria included neurosurgical resection prior to treatment and treatment of non-malignant histologies or primary central nervous system malignancies. A univariate screen was implemented to determine which factors were associated with radionecrosis. The chi-square test or Fisher's exact test was used to compare the two groups for categorical variables, and the two-sample t-test or Mann-Whitney test was used for continuous data. Those factors that appeared to be associated with radionecrosis on univariate analyses were included in a multivariable model. Univariable and multivariable Cox proportional hazards models were used to assess potential predictors of time to local failure and time to regional failure. RESULTS/UNASSIGNED:A total of 107 evaluable patients with a total of 256 individual brain metastases were identified. The majority of metastases were non-small cell lung cancer (58.98%), followed by breast cancer (16.02%). Multivariable analyses demonstrated increased risk of radionecrosis with increasing MRI maximum axial dimension (OR 1.10, p=0.0123) and a history of previous whole brain radiation therapy (OR 3.48, p=0.0243). Receipt of stereotactic radiosurgery with concurrent immunotherapy was associated with a decreased risk of local failure (HR 0.31, p=0.0159). Time interval between diagnostic MRI and first treatment, time interval between CT simulation and first treatment, and concurrent immunotherapy had no impact on incidence of radionecrosis or regional failure. DISCUSSION/UNASSIGNED:An optimal time interval between diagnosis and treatment for intact brain metastases that minimizes radionecrosis and maximizes local and regional control could not be identified. Concurrent immunotherapy does not appear to increase the risk of radionecrosis and may improve local control. These data further support the safety and synergistic efficacy of stereotactic radiosurgery with concurrent immunotherapy.

Sinking skin flap syndrome is a rare syndrome leading to increased intracranial pressure, known to neurosurgeons, yet uncommon and hardly ever reported in trauma patients. In a hospitalized trauma patient with declining neurological status, rarely do we encounter further deterioration by elevating the patients' head, diuresis and hyperventilation. However, after craniectomy for trauma, a partially boneless cranium may be compressed by the higher atmospheric pressure, that intracranial pressure rises to dangerous levels. For such cases, paradoxical supportive management with intravenous fluid infusion, and reverse Trendelenburg positioning, is used to counteract the higher atmospheric pressure, as a bridge to definitive treatment with cranioplasty. These steps constitute an urgent and easily applied intervention to reduce further neurological deterioration, of which every trauma healthcare provider should be aware.

This paper discusses the modern neurosurgeon's use of advanced magnetic resonance imaging in pre-operative and perioperative planning. The effect of advanced imaging on the risk and benefit analysis of surgery is discussed in particular