Giant colloid cysts are rare, benign lesions typically located in the third ventricle, accounting for approximately 2% of primary brain tumors and 15%-20% of intraventricular masses. Although small colloid cysts are relatively common, giant colloid cysts measuring over 3 cm are exceedingly rare and pose significant surgical challenges due to their size and critical anatomical location. This study retrospectively analyzes a series of 5 cases of giant colloid cysts from our local experience, in addition to a comprehensive literature review including 38 studies comprising 48 patients. Surgical approaches evaluated included transcallosal and transcortical craniotomy, endoscopic resection, and stereotactic aspiration. Complete cyst excision was achieved in 44 (83.0%) cases. Postoperative complications included seizures, hemiparesis, hydrocephalus, and cognitive dysfunction, though most patients demonstrated favorable recovery, particularly following complete excision. Our findings suggest that open craniotomy provides the highest rates of complete resection and remains preferable for very large, adherent, or anatomically complex giant colloid cysts, whereas endoscopic resection offers a minimally invasive alternative with acceptable outcomes in carefully selected cases with favorable ventricular anatomy. This study highlights the importance of timely diagnosis, individualized surgical approach selection, multidisciplinary care, and long-term follow-up to optimize patient outcomes and minimize complications.

Intracerebral hemorrhage is frequently complicated by hematoma expansion, which is a major determinant of poor outcomes. Leakage sign, defined as progressive contrast extravasation on delayed computed tomography after angiography, has been proposed as a predictor of hematoma expansion. However, the relationship between onset-to-imaging time, hemorrhage location, and leakage sign positivity remains unclear. Data from 144 patients with primary supratentorial intracerebral hemorrhage were retrospectively collected and divided into 2 groups: leakage sign-positive (n = 58) and leakage sign-negative (n = 86) groups. Clinical characteristics, radiological findings, and outcomes were compared, and correlations between hematoma size, onset-to-imaging time, and blood pressure at admission were assessed. Leakage sign-positive patients were significantly older, more frequently underwent antithrombotic therapy, and exhibited larger hematomas, a higher incidence of spot sign(s), a greater need for surgical intervention, and worse outcomes than their leakage sign-negative counterparts. Leakage sign was detectable within 5 hours of onset. In putaminal hemorrhage, hematoma size demonstrated a significant time-dependent increase, particularly in patients who were leakage sign-positive. Moreover, in leakage sign-positive putaminal hemorrhage, admission systolic blood pressure was strongly correlated with hematoma size, suggesting a synergistic effect between hypertension and ongoing bleeding. In contrast, there was no significant correlation between time and hematoma size in thalamic or subcortical hemorrhages, although trends were noted in subcortical cases. These findings indicate that leakage sign positivity reflects ongoing hyperacute bleeding, with diagnostic validity limited to within 5 hours of onset. Early detection of leakage sign, especially in cases of putaminal hemorrhage, may help identify high-risk patients who could benefit from aggressive interventions to mitigate hematoma expansion and improve outcomes.

Intracerebral hemorrhage is a severe type of stroke with high morbidity and mortality. Accurate assessment of hemorrhage phase is essential for determining treatment strategies, but magnetic resonance imaging evaluation remains subjective and lacks standardized criteria. This study aimed to create an objective method for estimating the phase of intracerebral hemorrhage using multi-sequence magnetic resonance imaging with 6 sequences: T1-weighted imaging, T2-weighted imaging, diffusion-weighted imaging, apparent diffusion coefficient map, fluid-attenuated inversion recovery, and T2 star-weighted magnetic resonance angiography. We retrospectively analyzed 56 patients with intracerebral hemorrhage. Magnetic resonance images used in this study were acquired using GE 1.5T scanners. Relative signal intensities were calculated using the pons as a reference, and a hemorrhage map was generated using color-coding pixels according to the 5 hemorrhage phases. Seven observers performed visual evaluations under 2 conditions: conventional image sets and hemorrhage maps. Diagnostic performance was assessed using precision-recall curves, average precision, and mean average precision. Interobserver agreement was evaluated using Fleiss' κ coefficient. The mean average precision of visual evaluation with the hemorrhage map was significantly higher than that of visual evaluation with original images (0.81 vs. 0.57, p < 0.01). Visual evaluation with hemorrhage map achieved "Almost perfect agreement" (κ = 0.85), whereas visual evaluation with original images demonstrated only "Slight agreement" (κ = 0.06). This study developed a novel diagnostic support method for estimating intracerebral hemorrhage phase using multi-sequence magnetic resonance imaging. By visualizing relative signal intensity as a color-coded hemorrhage map, the proposed method significantly improved both diagnostic accuracy and interobserver agreement compared with conventional visual evaluation.

Intraoperative transcranial motor-evoked potential recordings commonly utilize the belly tendon montage method; however, its reliability in large lower limb muscles such as the quadriceps femoris and hamstring muscles can be limited. We hypothesized that placing the reference electrode on the fibular head (fibular head reference electrode method) would improve waveform clarity and stability compared to belly tendon montage. This retrospective study analyzed 101 patients who underwent transcranial motor-evoked potential monitoring during spinal surgery at Nagoya University Hospital from October 2021 to August 2023. We compared compound muscle action potential amplitude, baseline waveform derivation success rate, noise amplitude, signal-to-noise ratio, and mean consecutive ratio between belly tendon montage and fibular head reference electrode method. Fibular head reference electrode method showed significantly higher median compound muscle action potential amplitudes in quadricep femoris (202.5 μV vs. 52.5 μV) and hamstring muscles (131.0 μV vs. 33.3 μV) with p < 0.001. Baseline waveform derivation success rates also improved with fibular head reference electrode method (quadricep femoris: 76.5% vs. 50.5%; hamstring muscles: 73.5% vs. 39.8%; p < 0.001). When noise amplitude increased, the signal-to-noise ratio improved significantly (p < 0.001), and mean consecutive ratio indicated better waveform stability in hamstring muscles. For predicting postoperative paralysis, fibular head reference electrode method yielded a sensitivity of 100% and a negative predictive value of 100% in both quadricep femoris and hamstring muscles, with specificities of 93.5% and 95.6%, respectively. These findings suggest that fibular head reference electrode method improves the reliability, clarity, and predictive value of transcranial motor-evoked potential monitoring in spinal surgery and may represent a superior alternative to conventional belly tendon montage.

This study aimed to describe the clinical characteristics of patients with human immunodeficiency virus-related brain lesions who underwent neurosurgical procedures in the antiretroviral therapy era. We retrospectively analyzed 27 neurosurgical procedures in 23 patients with human immunodeficiency virus from January 2013 to December 2023. The mean ages at human immunodeficiency virus diagnosis and surgery were 46.2 ± 12.7 years and 50.8 ± 13.8 years, respectively. At human immunodeficiency virus diagnosis, 18 patients (78.3%) met the criteria for acquired immunodeficiency syndrome, and 11 (47.8%) had a cluster of differentiation 4 count of <50 cells/μL. In total, 16 lesions were diagnosed as an acquired immunodeficiency syndrome-defining illness, including primary central nervous system lymphoma (n = 10), and 11 were diagnosed as a non-acquired immunodeficiency syndrome-defining illness. The mean viral load at surgery was higher in the acquired immunodeficiency syndrome-defining illness group (6.1 ± 11.9 × 10⁵ copies/mL) than in the non-acquired immunodeficiency syndrome-defining illness group (1.2 ± 2.8 × 10⁵ copies/mL, p = 0.009). The time from human immunodeficiency virus diagnosis to surgery was shorter in the acquired immunodeficiency syndrome-defining illness group (7.0 ± 25.2 months vs. 50.6 ± 63.8 months, p = 0.003). A significantly greater number of patients with non-acquired immunodeficiency syndrome-defining illness than acquired immunodeficiency syndrome-defining illness had been treated with antiretroviral therapy for >3 months (72.7% vs. 12.5%, respectively; p = 0.003). The introduction of antiretroviral therapy appears to have contributed to a decrease in brain lesions diagnosed as acquired immunodeficiency syndrome-defining illness, with a corresponding increase in those diagnosed as non-acquired immunodeficiency syndrome-defining illness.

Stereo-electroencephalography has recently gained attention as a less invasive and effective technique for presurgical evaluation in patients with drug-resistant epilepsy. Several studies have reported favorable outcomes when compared to conventional subdural electrode implantation. This study aimed to compare the target regions, complications, additional surgeries, and surgical outcomes between stereo-electroencephalography and subdural electrode implantation. A retrospective review was conducted on 83 consecutive patients who underwent intracranial electrode implantation between 2018 and 2024. Clinical variables were compared between the subdural electrode implantation (n = 41) and stereo-electroencephalography (n = 42) groups. In the stereo-electroencephalography group, 28 cases (66.7%) were implanted in the insular gyrus as the deep area, which was significantly different from the subdural electrode implantation group (8 cases, 19.5%). Resective surgery was performed in 39 subdural electrode implantation cases. In the stereo-electroencephalography group, 20 patients underwent resection, 14 received thermocoagulation, 5 were scheduled for surgery, and 3 were not eligible for surgery because the epileptogenic zone could not be identified. Intracranial hemorrhage occurred in 3 cases in each group. Two subdural electrode implantation cases were symptomatic and required reoperation, whereas all stereo-electroencephalography-related hemorrhages were asymptomatic. One year after surgery, seizure freedom was achieved in 57.9% (22 of 38 cases) of subdural electrode implantation and 64.0% (16 of 22 cases) of stereo-electroencephalography patients (p = 0.606). Seizure outcomes and complication rates were similar between stereo-electroencephalography and subdural electrode implantation, with fewer serious complications in the stereo-electroencephalography group. Stereo-electroencephalography was more frequently used in cases involving deep lesions or prior subdural implantation, highlighting its utility in technically challenging cases.

Chronic subdural hematoma remains one of the most common neurosurgical conditions in elderly patients, with anticoagulant use recognized as a major risk factor. This retrospective observational study investigated whether warfarin influences the temporal relationship between minor head trauma and the onset of neurological symptoms, here defined as the post-traumatic interval. Among 373 surgically treated patients between 2016 and 2022, only 126 with reliable trauma histories were included to minimize recall bias. Patients were stratified according to antithrombotic use (warfarin, aspirin, warfarin plus aspirin, or none). The median the post-traumatic interval was significantly shorter in the warfarin group compared with controls and aspirin users, suggesting that anticoagulation accelerates clinical manifestation. Warfarin was also associated with higher rates of bilateral hematomas, cerebral herniation, and poorer short-term functional outcomes, although most patients improved after surgical evacuation. The strict inclusion process reduced the sample size but increased the validity of the post-traumatic interval assessment, and the concept of the post-traumatic interval itself is not yet a validated clinical parameter. These findings raise the hypothesis that warfarin may shorten the latent period of chronic subdural hematoma through mechanisms of rebleeding and accelerated hematoma remodeling. Recognition of this effect could help clinicians anticipate earlier neurological deterioration in anticoagulated patients, underscoring the importance of early vigilance and imaging after seemingly trivial trauma in this high-risk population.