ABSTRACT
Detailed studies assessing the factors related to delayed cure of hemifacial spasm (HFS) after microvascular decompression (MVD) are sparse. We aimed to evaluate the effect of 11 clinical factors on the time until the patient became spasm free after MVD. We enrolled 175 consecutive patients with HFS who underwent MVD between 2012 and 2018. The end point was defined as the time point at which the patient became spasm free based on the outpatient interview. Patients were divided into six groups depending on when they became spasm free after the operation, as follows: <7 days ( n = 62), 7 days to 1 month ( n = 28), 1 to 3 months ( n = 38), 3 to 6 months ( n = 25), 6 to 12 months ( n = 17), and >12 months ( n = 5). The median time to become spasm free after MVD was 30.0 days. Association of 11 factors (age, sex, laterality, number of offending arteries, vertebral artery compression, number of compression sites, compression at root detachment zone, preoperative Botox treatment, indentation of the brain stem on preoperative magnetic resonance image, transposition, and interposition) with spasm-free rate was assessed using the Cox's proportional hazards model. Spasm-free rate curve after MVD for the significant factor was obtained using the Kaplan-Meier method. In univariate and multivariate analyses, nontransposition was significantly related to delayed HFS cure after MVD (hazard ratio [HR], 0.60; 95% confidence interval [CI], 0.42, 0.87; p = 0.0068 and HR, 0.60; CI, 0.43, 0.85; p = 0.042, respectively). The spasm-free rate was higher in the transposition than in the nontransposition group ( p = 0.0013). As shortening the time until spasm free after MVD improves patients' quality of life, transposition should be recommended. Prediction of spasm-free time could relieve the anxiety of postoperative patients.
ABSTRACT
Highly active electrocatalysts for the oxygen evolution reaction (OER) are essential to improve the efficiency of water electrolysis. The properties of OER active sites on single-crystal Pt electrodes were examined herein. The OER is markedly enhanced by repeated oxidative and reductive potential cycles on the Pt(111) surface. The OER activity on Pt(111) is nine times higher in the third cycle than that before the potential cycles. OER activation by potential cycling depends on the (111) terrace width, with wider (111) terraces significantly enhancing the OER. The oxidation/reduction of the Pt(111) surface produces atomic-sized vacancies on the terraces that activate the OER. Structural analysis using X-ray diffraction reveals that the active sites formed by potential cycling are defects in the second subsurface Pt layer. Potential cycling induces the bowl-shaped roughening of the electrode surface, wherein high-coordination number Pt atoms at the bottom of the cavities activate the OER.
ABSTRACT
BACKGROUND: In epilepsy surgery for cavernoma with intractable focal epilepsy, removal of the cavernoma with its surrounding hemosiderin deposition and other extended epileptogenic zone has been shown to improve postsurgical seizures. However, there has been no significant association between such an epileptogenic zone and intraoperative electrocorticography (ECoG) findings. The authors recently demonstrated that high regular gamma oscillation (30-70 Hz) regularity (GOR) significantly correlates with epileptogenicity. OBSERVATIONS: The authors evaluated the utility of intraoperative GOR analysis in epilepsy surgery for cavernomas. The authors also analyzed intraoperative ECoG data from 6 patients with cavernomas. The GOR was calculated using a sample entropy algorithm. In 4 patients, the GOR was significantly high in the area with the pathological hemosiderin deposition. In 2 patients with temporal cavernoma, the GOR was significantly high in both the hippocampus and the area with the pathological hemosiderin deposition. ECoG showed no obvious epileptic waveforms in 3 patients, whereas extensive spikes were observed in 3 patients. All patients underwent cavernoma removal plus resection of the area with significantly high GOR. The 2 patients with temporal cavernomas underwent additional hippocampal transection. All patients were seizure free after surgery. LESSONS: The high GOR may be a novel intraoperative marker of the epileptogenic zone in epilepsy surgery for cavernomas.
ABSTRACT
BACKGROUND: Mixed reality (MR) technology, which can fuse things in real and virtual space in real time, has been used mainly for simulation in neurosurgical training. OBJECTIVE: To develop MR technology into multimodal MR for intraoperative guidance during epilepsy surgery. METHODS: A 33-yr-old male patient suffered from intractable general tonic seizures due to left temporal meningoencephalocele. Preoperative scalp electroencephalograms localized interictal epileptic activity on the left temporal lobe. Iomazenil single photon emission tomography revealed temporal lobe lateralization. Magnetic resonance imaging (MRI) demonstrated left basal temporal meningoencephalocele extending into the pterygopalatine fossa through a bone defect at the base of the greater sphenoid wing. A 3-dimensional model was created for MR based on multimodal data including computed tomography, MRI tractography, and digital subtraction angiography, which enabled 3-dimensional visualization of abnormal subcortical fiber connections between the meningoencephalocele and the epileptic focus. RESULTS: By using intraoperative multimodal MR, we were able to safely remove the meningoencephalocele and perform epileptic focus resection. The patient was seizure-free postoperatively, and no adverse effects were noted. CONCLUSION: Intraoperative multimodal MR was a feasible and effective technique, and it can be applied for a wide range of epilepsy surgeries.
