Isocitrate dehydrogenase (IDH) wild-type diffuse astrocytic tumors tend to be pathologically diagnosed as glioblastomas (GBMs). We previously reported that myoinositol to total choline (Ins/Cho) ratio in GBMs on magnetic resonance (MR) spectroscopy was significantly lower than that in IDH-mutant gliomas. We then hypothesized that a low Ins/Cho ratio is a poor prognosis factor in patients with GBMs, IDH-wild-type. In the present study, we calculated the Ins/Cho ratios of patients with GBMs and investigated their progression-free survival (PFS) and overall survival (OS) to determine their utility as prognostic marker. We classified patients with GBMs harboring wild-type IDH (n = 27) into two groups based on the Ins/Cho ratio, and compared patient backgrounds, pathological findings, PFS, OS, and copy number aberrations between the high and low Ins/Cho groups. Patients with GBMs in the low Ins/Cho ratio group indicated shorter PFS (P = 0.021) and OS (P = 0.048) than those in the high Ins/Cho group. Multivariate analysis demonstrated that the Ins/Cho ratio was significantly correlated with PFS (hazard ratio 0.24, P = 0.028). In conclusion, the preoperative Ins/Cho ratio can be used as a novel potential prognostic factor for GBM, IDH-wild-type.

Hemifacial spasm (HFS) patients occasionally present with preoperative facial weakness (PFW) or develop delayed facial palsy (DFP) after microvascular decompression (MVD). This study is aimed to evaluate the neurophysiology underlying facial nerve motor dysfunction in HFS patients preoperatively and postoperatively. In all, 54 HFS patients without prior botulinum toxin injection who underwent MVD were retrospectively reviewed. The compound muscle action potential (CMAP) amplitude ratios of the affected and unaffected facial nerves, measured at 4 time points from preoperation to 1 year post-surgery, were aggregated. Clinical outcomes and the CMAP amplitude ratios were evaluated. Six patients (11.1%) presented with PFW, which correlated with advanced age (p = 0.007) and symptom duration (p = 0.001). The average duration to achieve PFW relief was 2.67 months postoperatively. The preoperative CMAP amplitude ratios of PFW patients were lower than those of patients without PFW (85.3% vs 95.7%). The ratios showed the lowest value at 1-week post-surgery in both groups (70.3% vs 90.9%), had a tendency toward improvement at 1 month, and finally recovered to almost the same level as that before the surgery at 1 year. Three patients (5.6%), whose CMAP ratios showed a persistent decrease from 1 week (56.5%) to 1 month (31%) after MVD, developed DFP. This study illustrates PFW in HFS patients reflects facial nerve axonal stress. MVD is effective in resolving spasm and PFW, without long-term damage to the facial nerve in most patients. In DFP patients, the direct and subsequent secondary axonal disorder develops on the postoperative facial nerve.

Cone beam computed tomography (CBCT) images are degraded by artifacts due to endovascular implants. We evaluated the use of streak metal artifact reduction technique (SMART) in non-contrast CBCT images after endovascular neurosurgery obtained from 148 patients (125 with aneurysm and 23 with dural arteriovenous fistula [dAVF]). Three neurosurgeons evaluated the cistern and brain surface visibility in CBCT images with and without SMART correction based on a 4-point scale (1, excellent; 2, good; 3, limited; and 4, insufficient). Significant improvement in visibility was achieved when the median scores improved from 4 or 3 to 2 or 1 or from 2 to 1. Metal artifact reduction in adjacent slices without metal and new artifacts after SMART correction was also examined. A significant improvement was achieved regarding the visibility of the cistern in 90 (60.8%) images and of the brain surface in 108 (73.0%) images. Metal size (cistern: odds ratio [OR], 0.91 per 1 mm increase; 95% confidence interval [CI], 0.83–0.99), irregular metal shape (cistern: OR, 0.18; 95% CI, 0.05–0.60 and brain surface: OR, 0.15; 95% CI, 0.05–0.45), and infratentorial lesions (cistern: OR, 0.37; 95% CI, 0.14–0.96 and brain surface: OR, 0.30; 95% CI, 0.11–0.80) were negatively correlated with improved visibility. Metal artifact reduction in adjacent slices without metal was obtained in 25.6% and 34.8% of images with aneurysm and dAVF, respectively. New artifacts after SMART correction were found in 4.8% and 13.0% of images with aneurysm and dAVF, respectively. SMART is especially effective for supratentorial small aneurysms.

In device-aided therapy (DAT) for Parkinson’s disease (PD), factors such as device-related adverse effects, psychological and lifestyle changes, and specific disease progression can affect the quality of life (QoL) of patients with advanced PD. However, there is no existing QoL scale that includes the effects of therapeutic devices. From a semi-structured interview with patients with PD undergoing deep brain stimulation (DBS), we extracted the content of utterances that were thought to affect the QoL and created a draft questionnaire consisting of 113 items. This questionnaire was administered to 54 other patients undergoing DBS, whose data were examined for reliability and validity by factor analysis, and finally, a 24-item PD QoL questionnaire for patients on DAT (PDQ-DAT) was developed. Presently, the PDQ-DAT is the only scale that can assess the QoL of patients on DAT, including the influence treatment devices have on them. In the future, it might be used to help in shared decision-making in medicine by incorporating the patient’s sense of burden and values in the selection of treatment methods.

The current study aimed to evaluate the relationship between preoperative neuroradiological findings and intraoperative bulbocavernosus reflex (BCR) amplitude in patients with intradural extramedullary tumors. A total of 24 patients with lesions below the 12th thoracic vertebra were included in the analysis. Objective and subjective urinary symptoms were investigated using data obtained from medical records and the core lower urethral symptom score (CLSS) questionnaire. The lesion compression rate was evaluated with MRI. In the epiconus-to-conus medullaris (Epi-CM) group, BCR amplitude changes were found to be correlated with the compression rate (p <0.05). The preoperative CLSS of the group with a BCR amplitude of <50% was worse than that of the group with ≥50% (p <0.01). The group did not experience symptom improvement 6 months postoperatively based on the CLSS. The preoperative CLSS of the group with compression rate of ≥80% on imaging was worse than that of the group with <80% (p <0.05). In the group with preoperative compression rate of ≥80%, CLSS at 1 month and 6 months postoperatively was improved as compared to preoperative CLSS (p <0.01, p <0.05). Hence, BCR amplitude changes are associated with the degree of lesion compression on preoperative images and pre- and postoperative urinary symptoms. Patients with intradural extramedullary Epi-CM lesions with strong compression are likely to present with low BCR amplitude and worsened postoperative symptoms. It is considered that the risk of postoperative urinary symptoms increases even with careful surgical manipulation under these conditions.

The increased use of neuroimaging and the aging of society have changed the incidence and proportion of histological types of intracranial tumors in Japan. A population-based epidemiological survey has been reported only from Kumamoto Prefecture. We performed a 10-year survey in Miyazaki Prefecture to compare our findings with the incidence rate (IR) of primary intracranial tumors (PIT) reported in the Kumamoto survey. Our study included 1915 new cases of PIT diagnosed in Miyazaki Prefecture between 2007 and 2016. The crude IR was 16.97/100000/year. The most common tumor was meningioma (46.3%), followed by glioma (17.1%), pituitary adenoma (13.1%), schwannoma (8.2%), and malignant lymphoma (3.8%). The age-specific IR of all PITs and of meningiomas, gliomas, pituitary adenomas, schwannomas, lymphomas, and germ cell tumors was similar in both prefectures. To directly compare with the age-adjusted IRs reported in the Kumamoto survey, we calculated the IR for the two prefectures. The age-adjusted IR of primary brain tumors in Miyazaki Prefecture was 14.65/100000/year, which was slightly higher than in the Kumamoto survey (14.09/100000/year between 1989 and 2008). The age-adjusted IR of glioma, schwannoma, and malignant lymphoma showed only a small difference between Miyazaki and Kumamoto. However, the age-adjusted IR of meningiomas was higher in Miyazaki than Kumamoto (6.15- vs. 4.97/100000/year), but the IR of pituitary adenoma was higher in Kumamoto than Miyazaki (2.66- vs. 2.13/100000/year). Although there were some differences between the two surveys, the IR of PIT showed a similar pattern in Kumamoto and Miyazaki, which are neighboring districts on Kyushu Island.

Brain bulging is an unfavorable outcome in patients with brain swelling who require decompressive craniectomy (DC) to control elevated intracranial pressure (ICP). Although several previous studies have described methods for reducing the operation time during DC in these patients, few have proposed a technique for controlling brain protrusion. Here we describe an effective and simple method for external reduction of ICP and discuss its suitability for patients at risk of brain bulging during DC. After craniectomy, crank-shaped lines extending from a central square dural canopy are all marked on the dura. As the incisions are made, pressure from the swelling brain opens the lines and the protruding cortical surface forms dural windows. The square canopy gradually rotates as it stretches, and along with the remaining dura, functions to gently support and compress the cortex. In the case of insufficient decompression, the incision lines can be extended to further reduce ICP. As the parenchyma is accessible to the surgeon, hematoma removal can be performed through the dural windows. In initial experience of four patients who underwent this technique, ICP was controlled in all cases after surgery and no adverse events occurred. The crank-shaped dural incision method is a simple, quick, and effective technique for external reduction of ICP in patients at risk of brain bulging that is intuitive in the emergency situation and thus can be performed even by relatively inexperienced neurosurgeons.