December 2025

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Functional and Structural Connectivity Correlates of Axial Symptom Outcomes After Pallidal Deep Brain Stimulation in Parkinson’s Disease

Stimulation of the globus pallidus interna (GPi) is a safe and established therapy for management of refractory motor fluctuations. However, GPi deep brain stimulation has been associated with divergent axial gait outcomes. The doctors retrospectively studied 19 Parkinson’s disease patients who underwent bilateral GPi deep brain stimulation (DBS), assessing UPDRS-III (Unified Parkinson's Disease Rating Scale) axial gait subscores at baseline and 36 months. The study examined how the volume of tissue activated within the GPi communicates with the rest of the brain, using measures of structural and functional connectivity derived from diffusion tractography and normative resting state fMRI, and related these patterns to clinical outcomes. Improvement in axial gait after GPi-DBS was associated with connectivity to sensorimotor and supplementary motor networks, whereas worsening correlated with connectivity to cerebellar Crus II, occipital, and thalamic regions. These findings suggest that, rather than relying solely on anatomic GPi localization, connectomic mapping should be incorporated into surgical planning, as preferential engagement and avoidance of aforementioned networks could decrease the incidence of divergent axial gait outcomes.

Disseminated pediatric low-grade glioma and hydrocephalus: a multinational consortium analysis of incidence and mortality

In disseminated pediatric low-grade glioma (DPLGG), pediatric low-grade gliomas (PLGGs) spread and result in multifocal CNS tumors or leptomeningeal involvement. PLGGs tend to develop near cerebrospinal fluid pathways of the brain, causing compression and contributing to the development of hydrocephalus. This multinational retrospective cohort study sought to better understand the clinical characteristics, treatments, and outcomes of patients with concomitant DPLGG and hydrocephalus in a post-hoc analysis of data across 39 institutions over 47 years. 145 of 261 patients with DPLGG had hydrocephalus treated with CSF diversion, most commonly with ventriculoperitoneal shunts. These patients had no differences in mortality when compared to patients with DPLGG without concomitant hydrocephalus. However, academic difficulties and endocrine dysfunction were more prevalent in the DPLGG with hydrocephalus cohort. Furthermore, tumors with diffuse leptomeningeal glioneuronal tumor histopathology demonstrated significantly increased odds of hydrocephalus as compared to pilocytic astrocytomas, while pilomyxoid astrocytomas were associated with reduced odds. 

EMBOLISE randomized surgical trial for subdural hematoma: clinical benefits beyond reoperation with middle meningeal artery embolization

Chronic subdural hematoma has a high recurrence rate after surgery, often requiring reoperation. Middle meningeal artery (MMA) embolization has been increasingly adopted to address this problem. However, the amount of data on its true clinical benefit has been limited. In this multicenter randomized trial, 400 patients with symptomatic non-acute subdural hematoma were assigned to standard management (including burr-hole drainage and postoperative care) with or without supplemental MMA embolization and followed for 90-day outcomes. The primary outcome of this study was symptomatic recurrence or progression within 90 days. Ultimately, investigators found that patients who did not receive MMA embolization had an approximately threefold higher recurrence rate than the MMA embolization group (14.3% vs 5.3%, P = 0.0045). Patients receiving MMA embolization also experienced fewer serious adverse effects and a more favorable clinical course. These results suggest that MMA embolization provides a meaningful benefit beyond conventional surgical treatment and may improve both short and long-term outcomes in patients with chronic subdural hematoma.

Reconsidering flexion-extension imaging: the emerging role of supine MRI and upright radiographs in isthmic lumbar spondylolisthesis

Detecting dynamic instability in isthmic lumbar spondylolisthesis (ILS) may not require dynamic imaging. This study compares the clinical utility of the gold-standard flexion-extension (FE) radiography versus a combination of already routinely collected standing radiograph and supine (US) imaging. The findings support that US imaging provides superior detection of segmental instability and a higher association with pain and degeneration in ILS. This is significant because detecting instability in ILS directly informs whether fusion is necessary. In this retrospective cross-sectional cohort study of 78 patients treated for isolated L5/S1 ILS, segmental relative translation (RT) — quantified by normalized posterior sagittal translation (%) — and radiographic instability (RT ≥ 8%) were calculated using both FE and US imaging. Additionally, the study assessed associations with back pain, disc degeneration, paraspinal muscle degeneration, and spinopelvic alignment. US imaging demonstrated a statistically significant increase in the ability to detect segmental motion and radiographic instability (64 vs. 34 patients). Also, only US imaging showed significant associations with back pain intensity and disc degeneration. These findings suggest that US imaging is a practical alternative for screening ILS, reducing the radiation exposure each patient must endure from additional FE radiography.

Use of Quantitative Pupillometry in the Neuro Intensive Care Unit Setting 

Quantitative Pupillometry (QP) is an evolution of manual pupillometry allowing for an objective method to evaluate pupillary metrics, such as the Neurological Pupil index (NPi). QP has readily increased as a non-invasive, proactive tool for informing clinical decision making, but better understanding of its efficacy was necessary. A literature review analyzed 52 original articles between 1995 and 2025 using keywords to siphon through the initial 1,030 articles, focusing on those in the neuro ICU with traumatic brain injuries (TBIs), subarachnoid hemorrhages (SAHs), and intracranial hemorrhages (ICHs). It established that abnormal NPi values (defined as values < 3) have a strong correlation with increased ICP, often preceding episodes of elevated intracranial pressure (ICP) by up to 16 hours, serving as the strongest predictive value for ICP compared to other pupillometry metrics. Abnormal NPi values are therefore useful to screen for elevated ICP (> 20 mmHg), noting an association with unfavorable 6-month outcomes. Tracking NPi as a surrogate for ICP may be useful as a predictive model to anticipate elevated ICP and its associated complications, allowing ample time for preventative measures. 

Breaking the Blood–Brain Barrier in Glioblastoma

Despite the advent of treatments like immunotherapy and tumor-treating fields, glioblastoma remains one of the worst CNS prognoses a person can receive. However, the recent BT008NA trial by Woodworth et al. could represent a paradigm shift in the treatment of this deadly disease. This study demonstrated that microbubble-enhanced focused ultrasound (MB-FUS) can safely and reliably open the blood–brain barrier (BBB), enhancing chemotherapeutic delivery and addressing one of neuro-oncology’s most fundamental challenges: effective drug penetration across the BBB. BT008NA was a multicenter phase 1/2 trial that enrolled 34 patients with newly diagnosed glioblastoma who received monthly MB-FUS treatments during adjuvant temozolomide infusions. The authors found that this protocol achieved BBB opening in all 176 treatments with mainly grade 1-2 adverse events and no treatment-related deaths. Median overall survival was 31.3 months, notably exceeding historical benchmarks of 14-21 months in matched controls. Interestingly, they also found that MB-FUS allowed for non-invasive “liquid biopsy,” with changes in plasma cell-free DNA correlating with patient survival outcomes. Overall, this trial demonstrates that the use of MB-FUS in conjunction with temozolomide can not only improve drug delivery and extend survival but also enable better monitoring of tumor burden. 

2023 Guideline for the Management of Patients With Aneurysmal Subarachnoid Hemorrhage: A Guideline From the American Heart Association/American Stroke Association 

In 2023, the American Heart Association (AHA)/American Stroke Association (ASA) released updated guidelines on the management of aneurysmal subarachnoid hemorrhage (aSAH) emphasizing the continuum of care. The 2023 guidelines are limited to aSAH and do not address other types of SAH or treatment of intracerebral hemorrhage, arteriovenous malformations, and unruptured intracranial aneurysms. These guidelines provide an exhaustive summary of recommendations on the course of care in aSAH patients. Class I recommendations in acute treatment of aSAH includes I. use of clinical grading scales such as Hunt/Hess for clinical severity and outcome prediction; II. non-contrast head CT and, if negative and suspicion remains high, lumbar puncture in patients with severe headache >6hr from symptom onset or those with new neurologic deficits; III. timely transfer to a high-volume tertiary care center and admission to a neurologic ICU with multidisciplinary care; IV. surgical or endovascular treatment of ruptured aneurysms performed as early as feasible, preferably within 24hrs of onset; and V. complications (mechanical ventilation, vasospasm, hydrocephalus, venous thromboembolism) should be managed promptly using evidence-based guidelines. This summary of recommendations should be supplemented by review of the full article to guide acute management of aSAH.

Long-Term Efficacy of Anterior Nucleus of the Thalamus Deep Brain Stmiulation in Drug-Resistant Epilepsy: A 5-Year Multicenter Study

Deep brain stimulation (DBS) has become an established surgical option for patients with drug-resistant epilepsy, especially where resective surgery cannot be adopted. This study demonstrates that, when medical therapy fails, targeting the anterior nucleus of the thalamus (ANT) with DBS represents a surgical option for reducing seizure frequency. However, by reinforcing the importance of the thalamocortical networks in seizure propagation, this study aims at helping neurosurgeons identify the proper candidates for ANT DBS and and set expectations preoperatively. In this retrospective multicenter cohort study of 40 patients (mean age 28.6 years), ANT DBS resulted in a reduction in seizure frequency (SF), with an overall 56.7% decrease in SF at 5-year follow-up. Improvements in emotional well-being, energy, and social functioning were observed, suggesting an improvement in quality of life without a decline in cognitive functions. Moreover, multivariate analysis identified seizure onset zone as a key prognostic factor, with temporal lobe epilepsy emerging as an independent predictor of responder status and seizure reduction, along with stimulation amplitude. Overall, this study supports ANT DBS as an effective long-term neurosurgical therapy and highlights prognostic factors that may optimize patient selection and surgical outcomes.

Diagnostic utility of additional spine imaging for syrinx detection in the pre-operative assessment of pediatric Chiari malformation type 1

In pediatric patients with Chiari malformation type 1 (CMT1), the inferior displacement of the cerebellum through the foramen magnum may be associated with syringomyelia, a fluid-filled cavity within the spinal cord that most commonly involves the cervical region. Evaluation of syringomyelia using MRI can be a burdensome experience for these patients, potentially requiring sedation or endotracheal intubation. This retrospective cohort study of patients with CMT1 who underwent surgical decompression to assess whether preoperative cranial MRI alone is sufficient for syrinx detection. 41 of 44 syrinxes were identifiable through cranial MRI alone. Cranial MRI had 93.2% sensitivity to and 93.3% negative predictive value for syrinx detection. The diagnostic yield of additional spine MRI in cranial MRI-negative patients was low. Thus, this study suggests that in the neurosurgical management of CMT1, preoperative brain MRI may be sufficient to assess for syringomyelia, potentially reducing cost, patient burden, and risks associated with anesthesia without compromising diagnostic accuracy.

Transradial Versus Transfemoral Access for Mechanical Thrombectomy in Acute Ischemic Stroke: An Update Meta-Analysis and Trial Sequential Analysis

Transradial access (TRA) for mechanical thrombectomy is a promising new alternative to the gold standard of transfemoral access (TFA) in acute ischemic stroke (AIS), possibly reducing access site complications while maintaining comparable outcomes. This meta-analysis compares outcomes of TRA and TFA in patients with AIS.The outcomes of 763 TRA and 3527 TFA patients were analyzed. Odds ratios (OR) and mean differences (MD) were calculated for the defined primary outcomes: successful recanalization (OR 0.88), puncture-to-recanalization time (MD -1.67), favorable outcomes at 3 months (OR 0.85). No statistically significant differences were found between TRA and TFA for any of the primary outcomes. Measured secondary outcomes included complete recanalization (OR 1.15), first pass effect (OR 0.83), crossover (OR 1.71), number of passes (MD 0.17), access site complications (OR 0.70), symptomatic intracranial hemorrhage (OR 0.93), and length of hospitalization (MD -0.59). No statistically significant differences were found between TRA and TFA for any of the secondary outcomes. However, several outcomes were close to statistical significance, highlighting the necessity of larger randomized controlled trials in the future. Overall, these findings suggest that TRA may be a safe and effective alternative to TFA, though further studies are needed to draw definitive conclusions.

Anterior Cervical Discectomy and Fusion Using Cages With Different Sized Windows

Cage window size might matter more than graft volume in anterior cervical discectomy and fusion (ACDF). This study marks a shift from the traditionally thinking that using larger cage dimensions and maximizing bone graft volume lowers subsidence risk. It concludes that larger windows possess a higher risk of subsidence and suggests that the optimum metric should be cage-to-endplate contact area. In a prospective, single-blinded, randomized controlled trial, patients undergoing ACDF received PEEK interbody cages with large (n=32), middle (n=30), and small internal cage windows (n=33). At 12 months, subsidence, fusion rates (Extracage and Intracage Bridging Bone scores), and clinical outcomes (NDI, JOA, and VAS scores) were analyzed. At one- and twelve-month(s) postoperatively, subsidence rates proved significantly higher in the large window group (51.9%) compared to middle (27.7%) and small (17.3%) window groups. Importantly, different window size did not appear to impact fusion rates or clinical outcomes. These results indicate surgeons should avoid using cages with a larger window size to reduce the risk of subsidence.

Severe Pediatric Traumatic Brain Injury Presenting Characteristics: Abusive Versus Accidental Trauma

Due to the lack of research and restrictions regarding accidental traumatic brain injury (TBI) rates in infants, it is unclear whether available therapies are appropriate for treatment of both accidental TBIs (aTBI) and abusive head trauma (AHT). This study is a secondary analysis characterizing children within the Approaches and Decisions in Acute Pediatric TBI (ADAPT) trial, according to the mechanism of TBI, abusive vs accidental. In total, 313 children <5 years old were analyzed for differences in clinical presentation of their associated TBI and further stratified according to age to be evaluated for clinical differences. It was found that apnea, seizures, subdural hemorrhages, and ischemia were more common in AHT while early parenchymal disruption, subarachnoid hemorrhage, and DAI were common in aTBI. Age-stratified findings showed higher ischemia rate in children with AHT <1 year and 3-4.9 years old and higher seizure rate in children 1-2.9 years old. Currently, pediatric treatment practices do not take the mechanism of head trauma into account when it does play a significant role in pathophysiology and presentation. Therefore, current TBI therapies may not be appropriate for pediatric AHT treatment. 

Proton Craniospinal Irradiation for Patients With Leptomeningeal Metastasis

Involved-field radiotherapy (IFRT) is currently the standard for palliative management of leptomeningeal metastasis (LM), which is the spread of cancer cells from a primary tumor to the brain, spine, CSF and surrounding membranes(leptomeninges); however, it fails to address disease dissemination throughout the neuroaxis(brain and spinal cord). This study indicates that proton craniospinal irradiation (pCSI) can be a superior alternative by treating the entire CNS compartment while sparing healthy tissue, providing an interesting insight for the management standard of solid tumor leptomeningeal metastasis. This study was an open-label, randomized phase 2 trial consisting of 98 patients (63 randomized, 35 exploratory) with solid tumor LM, primarily metastasizing from non-small cell lung cancer and breast cancer. Patients were randomized to receive either pCSI or photon IFRT (standard of care) with the primary outcome being CNS progression-free survival (CNS-PFS). Patients treated with pCSI demonstrated significantly improved median CNS-PFS (8.2 months vs 2.3 months) and median overall survival (11.3 months vs 4.9 months) compared to those receiving IFRT. The strong evidence for efficacy of pCSI led to the discontinuation of the trial, supporting its use as a treatment option.

Indications for Intracranial Pressure Monitoring

In 2007, the Brain Trauma Foundation systematically reviewed evidence on intracranial pressure monitoring in traumatic brain injury (TBI) to form consensus recommendations. In TBI, only a portion of the actual injury occurs at the time of impact while additional secondary insults continue due to alterations in cerebral oxygenation and perfusion. Poorer outcomes have been shown with cerebral perfusion pressure (CPP) <50 mmHg. The foundation found that patients with intracranial abnormalities on CT had poorer outcomes. Additionally, the foundation determined that invasive monitors provided useful data on CPP approximating mean arterial pressure and intracranial pressure (ICP). Finally, the foundation found that patients responsive to ICP lowering therapy have improved outcomes, therefore invasive pressure monitoring is useful in assessing treatment response. In summary, ICP should be monitored in I. moderate-severe TBI patients who cannot be serially neurologically assessed; II. all salvageable patients with severe TBI [Glasgow coma scale (GCS) ≤8 after resuscitation] and an abnormal CT scan; III. in patients with severe TBI with a normal CT scan with ≥2 of the following features on admission: age ≥40, unilateral/bilateral motor posturing, or systolic blood pressure < 90 mmHg.