Real-time display of intracranial subdural electrodes and the brain surface during an electrode implantation procedure using permeable film.

Background: Subdural electrode (SDE) implantation is an important method of diagnosing epileptogenic lesions and mapping brain function, even with the current preference for stereoelectroencephalography. We developed a novel method to assess SDEs and the brain surface during the electrode implantation procedure using brain images printed onto permeable films and intraoperative fluoroscopy. This method can help verify the location of the electrode during surgery and improve the accuracy of SDE implantation. Methods: We performed preoperative imaging by magnetic resonance imaging and computed tomography. Subsequently, the images were edited and fused to visualize the gyrus and sulcus better. We printed the images on permeable films and superimposed them on the intraoperative fluoroscopy display. The intraoperative and postoperative coordinates of the electrodes were obtained after the implantation surgery, and the differences in the locations were calculated. Results: Permeable films were created for a total of eight patients with intractable epilepsy. The median difference of the electrodes between the intraoperative and postoperative images was 4.6 mm (Interquartile range 2.9-7.1). The locations of electrodes implanted outside the operation field were not significantly different from those implanted inside. Conclusion: Our new method may guide the implantation of SDEs into their planned location.

Vagus Nerve Stimulation Therapy for Drug-Resistant Epilepsy in Children-A Literature Review.

Vagus nerve stimulation (VNS) is a palliative treatment for drug-resistant epilepsy (DRE) that has been in use for over two decades. VNS suppresses epileptic seizures, prevents emotional disorders, and improves cognitive function and sleep quality, a parallel effect associated with the control of epileptic seizures. The seizure suppression rate with VNS increases monthly to annually, and the incidence of side effects reduces over time. This method is effective in treating DRE in children as well as adults, such as epilepsy associated with tuberous sclerosis, Dravet syndrome, and Lennox-Gastaut syndrome. In children, it has been reported that seizures decreased by >70% approximately 8 years after initiating VNS, and the 50% responder rate was reported to be approximately 70%. VNS regulates stimulation and has multiple useful systems, including self-seizure suppression using magnets, additional stimulation using an automatic seizure detection system, different stimulation settings for day and night, and an automatic stimulation adjustment system that reduces hospital visits. VNS suppresses seizures and has beneficial behavioral effects in children with DRE. This review describes the VNS system, the mechanism of the therapeutic effect, the specific stimulation adjustment method, antiepileptic effects, and other clinical effects in patients with childhood DRE.

Angiographic challenges of spinal dural and epidural arteriovenous fistulas: report on 45 cases.

PURPOSE: The localization of the fistula level in spinal dural arteriovenous fistulas (dAVFs) and epidural arteriovenous fistulas (edAVFs) remains a diagnostic challenge. METHODS: Consecutive patients with spinal dAVFs and edAVFs in the thoracic, lumbar, and sacral regions were included. The primary endpoint was to describe the characteristics of patients who required angiography with multiple catheterizations of segmental arteries (10 or more). RESULTS: Forty-five patients (median age 69 years; male 89%; dAVFs, n = 31; edAVFs, n = 14) were included. Spinal dAVFs commonly developed in the thoracic region and edAVFs in the lumbosacral region. Fistulas were predicted at the correct level or plus/minus 2 level in less invasive examinations using multi-detector CT angiography (n = 28/36, 78%) and/or contrast-enhanced MR angiography (n = 9/14, 64%). We encountered diagnostic challenges in the localization of fistulas in 6 patients. They underwent angiography a median of 2 times. In each patient, spinal levels were examined at a median of 25 levels with a median radiation exposure of 3971 mGy and 257 ml of contrast. Fistulas were finally localized at the high thoracic region (T4-6) in 3 patients, the sacral region (S1-2) in 2, and the lumbar region (L3) in 1. Four patients were diagnosed with edAVFs and 2 with dAVFs. The correlation coefficient between the fistula level and the rostral end of the intramedullary T2 high-signal intensity on MRI was interpreted as none. CONCLUSION: In patients in whom less invasive examinations failed for fistula localization, high thoracic or sacral AVFs need to be considered.

Quantitative evaluation of hippocampal gray-white matter boundary blurring in medial temporal lobe epilepsy with hippocampal sclerosis.

INTRODUCTION: The magnetic resonance imaging (MRI) findings of hippocampal sclerosis (HS) include decreased volume, increased signal intensity, and hippocampal gray-white matter boundary blurring (HGWBB). Given that the layered structure is obscure in HS, there have been no reports on the quantitative evaluation of HGWBB and its relationship with the clinical outcome. Thus, this study aims to correlate the extent of HGWBB to its clinical manifestation of HS. METHODS: Fifty-four patients with temporal lobe epilepsy who underwent hippocampal resection were enrolled. To evaluate HGWBB quantitatively, we defined an index by calculating the standard deviation of the intrahippocampal signal on short tau inversion recovery. In addition, we created a prognostic scoring system using four criteria, including hippocampal signal intensity, size of hippocampal cross-sectional area, presence of temporal lobe lesions, and the HGWBB index. RESULTS: The HGWBB index was significantly lower on the affected side than on the unaffected side (p < 0.001). This trend was more prominent in the poor prognosis group than that in the good prognosis group. The prognostic scoring system revealed that when three or more criteria were positive, the prognostic accuracy reached 87.5% sensitivity and 71.7% specificity. CONCLUSION: The HGWBB index is useful for the diagnosis of temporal lobe epilepsy with HS and for predicting seizure outcomes when used with another index of hippocampal volume loss and increased signal intensity.

Surgical Strategy for Hemispherotomy.

Hemispherotomy is a radical treatment for drug-resistant epilepsy that targets developmental, acquired, and progressive diseases with widespread epileptogenic regions in one cerebral hemisphere. Currently, two main approaches are utilized after repeated improvements: lateral and vertical approaches. With the lateral approach, the surgical field is wide, and the approach to the lateral ventricle is relatively easy. On the other hand, the vertical approach has the advantage of reducing intraoperative bleeding and operating time as the resection line of the radial fiber is short, and understanding the three-dimensional anatomy is relatively easy. The lateral approach is generally used for atrophic lesions, whereas the vertical approach is for hypertrophic lesions. Hemispherotomy is expected to not only suppress epileptic seizures but also improve psychomotor development by protecting the unaffected cerebral hemisphere. However, this method is one of the most invasive surgeries in epilepsy surgery, and it is important to fully consider its indications. Furthermore, understanding the neural fiber pathway is important for actual surgery.

Sacral myolipoma with involuntary contraction causing tethered cord syndrome: illustrative case.

BACKGROUND: Spinal lipomas sometimes involve various ectopic tissues originating from the ectoderm, mesoderm, and endoderm in the process of morphological development. OBSERVATIONS: A 29-year-old male patient with myolipoma of the conus medullaris at the S2 and S3 levels was described. The unusual finding, involuntary muscle contraction, was presented in an operative video and a literature review. In the present case, sacral myolipoma with involuntary contraction caused tethered cord syndrome in adulthood, and untethering surgery resolved continuous buttock and leg pain. LESSONS: This rare finding is considered a surgical indication for adult patients with myolipoma.

Case report: The origin of transmantle-like features.

The transmantle sign is considered to be a magnetic resonance imaging feature specific to patients with type II focal cortical dysplasia; however, this sign can be difficult to distinguish from other pathologies, such as a radial-oriented white matter band in tuberous sclerosis. Here, we report a case showing a high-intensity area on T2-weighted and fluid-attenuated inversion recovery images extending from the ventricle to the cortex associated with atypical histopathological findings containing corpora amylacea. This case demonstrates that some instances of transmantle signs may be due to corpora amylacea accumulation.

Initial Report of the Perioperative Platelet Aggregation Test Using Hematracer ZEN in Neuroendovascular Therapy.

Objective: We report the characteristics of the platelet aggregation test using Hematracer ZEN (HTZ; DS medical, Tokyo, Japan) during the perioperative period. Methods: Among patients undergoing neuroendovascular treatment (EVT) at our hospital between June 2019 and June 2020, 42 consecutive patients with preoperative dual antiplatelet therapy (DAPT) were included. Oral administration of aspirin (ASA) at 81 mg and clopidogrel (CLP) at 75 mg was started 7 days before treatment (Flow Diverter [FD]: 14 days before). We evaluated platelet aggregation activity the day before treatment (FD: 2 days before) using HTZ. We adjusted the CLP dose according to the platelet aggregation test in each patient. We evaluated the platelet aggregating activity after EVT in patients requiring an intracranial stent or in which CLP was adjusted before EVT. Results: Platelet aggregating activity was able to be evaluated in all patients. In the preoperative examination, the efficacy of CLP was insufficient in one patient (2.4%), optimal medical effects were confirmed in 16 (38.1%), mildly excessive effects were noted in 10 (23.8%), and highly excessive effects were noted in 15 (35.7%). Reassessment was performed postoperatively in 20 patients. We switched CLP to prasugrel in one patient in which the CLP efficacy was considered insufficient in the preoperative evaluation. We reduced the CLP dose in seven patients with marked overdose, and the optimum range was reached in all. We did not adjust the CLP dose in 12 patients judged to have optimal or mildly excessive effects preoperatively, but 4 exhibited highly excessive drug efficacy and required CLP reduction. No postoperative symptomatic cerebral infarction or intracranial hemorrhage was observed (mean observation period: 11 months, range: 4-16 months). Conclusion: The platelet aggregation test using HTZ was simple and inexpensive, and was useful for adjusting the dose of antiplatelet drugs, but its utility should be evaluated in more patients.

Carotid Endarterectomy for Intractable Repetitive Stenosis Following Carotid Artery Stenting.

BACKGROUND: Restenosis after carotid artery stenting has raised concerns regarding the long-term durability of carotid stenting. Recurrent restenosis after multiple endovascular interventions may pose a challenge for clinicians. CASE DESCRIPTION: We encountered 2 cases of intractable restenosis after redo-carotid artery stenting and performed carotid endarterectomy. We removed the embedded stent and plaque simultaneously, used the internal shunting system, and performed patch angioplasty with no further recurrence. CONCLUSION: Carotid endarterectomy could be considered as a first-line treatment for recurrent stenosis that proves refractory to multiple endovascular interventions.

A Rare Anomalous Origin of the Right Vertebral Artery from the Internal Carotid Artery with an Aberrant Right Subclavian Artery.

BACKGROUND: An anomalous origin of the right vertebral artery (VA) from the right internal carotid artery (ICA) occurs only rarely. CASE DESCRIPTION: A 70-year-old man underwent carotid artery stenting for right internal carotid artery stenosis. In this patient, the right VA arose from the right ICA associated with an aberrant right subclavian artery. CONCLUSION: Embryologically, failure of involution of 1 of the first 6 intersegmental arteries causes various abnormal origins of the VA. The embryonic development of this anomaly is also reviewed.

Two cases of symptomatic common carotid artery occlusion treated by carotid endarterectomy with L-shaped ministernotomy.

BACKGROUND: Common carotid artery occlusion (CCAO) is rare. Symptomatic lesions are resistant to medical treatment and revascularization are often required, but there is no consensus on the treatment of CCAO. In this paper, two cases of symptomatic CCAO treated by carotid endarterectomy (CEA) with L-shaped ministernotomy, in which the lesions extended to the beginning part of the CCA, are reported. CASE DESCRIPTION: Case 1 involved a 74-year-old man who presented with transient left limb numbness and an abnormal right visual field. Cerebrovascular angiography showed that the right CCA was occluded immediately after its origin and blood was supplied from the posterior circulation. CEA was performed with an L-shaped ministernotomy that allowed exposure of the CCA origin with minimal invasion. There were no complications associated with the sternal incision and he was discharged with a modified Rankin Scale (mRS) score of 0. Case 2 involved a 70-year-old man who presented with left half-blindness. Magnetic resonance imaging showed infarction in the right posterior cerebral artery region and neck echo showed CCA pseudo occlusion just before the carotid bulb. A new infarction in the right middle cerebral artery region developed during hospitalization. CEA with partial sternotomy was performed. The patient was rehabilitated with no deterioration of neurological findings and transferred with an mRS score of 3. CONCLUSION: There were no complications resulting from partial sternotomy in the two cases presented. CEA with partial sternotomy could be an effective treatment option for CCAO in which the internal carotid artery is patent and thrombus extends to the proximal CCA.

Three-dimensional angioarchitecture and microsurgical treatment of arteriovenous fistulas at the craniocervical junction.

Digital subtraction angiography (DSA) is the gold standard for diagnosing vascular malformations; however, difficulties are associated with visualizing the angioarchitecture of arteriovenous fistulas at the craniocervical junction (CCJ AVFs) using DSA because of their complex regional neurovascular anatomy. The present study evaluated the application of 3-dimensional computer graphics (3D CG) to the surgical planning of CCJ AVFs. Six patients with CCJ AVFs who underwent microsurgery and/or endovascular treatment were included. The results of DSA and 3D CG were compared in the last 3 patients. The visibility of important anatomical structures were evaluated using visibility grading scores. Clinical outcomes were assessed based on the rate of occlusion of AVFs, surgical complications, neurological status, and recurrence in long-term follow-ups. The 3D CG images could combine arteries, veins, the spinal cord and dura mater in one single picture to evaluate the anatomy of CCJ AVFs. The image interpretation of vascular structures, particularly narrow arterial feeders, was significantly better using 3D CG than DSA (overall visibility scores, 97% vs 51%, p = 0.001). In all patients, the complete occlusion of AVFs was achieved by microsurgery except for 2 patients without surgical planning with 3D CG. Postoperatively, the neurological status of all patients improved or stabilized without the recurrence of AVFs (median, 5.4 years). 3D CG may help to improve the quality of the microsurgical procedures in complex AVFs. However, it should be used as a complementary diagnostic modality rather than the alternative of DSA because 3D CG has no hemodynamic information at this time.

[The Map of Auditory Function].

Brodmann areas 41 and 42 are located in the superior temporal gyrus and regarded as auditory cortices. The fundamental function in audition is frequency analysis; however, the findings on tonotopy maps of the human auditory cortex were not unified until recently when they were compared to the findings on inputs and outputs of the monkey auditory cortex. The auditory cortex shows plasticity after conditioned learning and surgery of cochlear implant. It is also involved in speech perception, music appreciation, and auditory hallucination in schizophrenia through interactions with other brain areas, such as the thalamus, frontal cortex, and limbic systems.

Life-threatening large subcutaneous hematoma after minor head trauma: A young female patient who was suspected of having new Ehlers-Danlos syndrome.

Life-threatening large subcutaneous hematomas after minor injury are rare clinical states for young people; however these patients may have hidden diseases, which can cause a tendency to bleed. A 31-year-old woman visited our hospital after minor injury. The first computed tomography (CT) scan revealed a small subcutaneous hematoma, but her head bulged and the second CT scan revealed her subcutaneous hematoma had become enlarged. Two surgeries were needed to stop the bleeding and. Though she received intensive care, she died 48 days after onset. The new Ehlers-Danlos syndrome (EDS), known as EDS Kosho type (EDSKT), is a connective tissue disease, in which patients often experience large subcutaneous hematomas. We suspected our patient had EDSKT because her clinical features were compatible with this syndrome. Our findings support the notion that large subcutaneous hematomas in young patients with connective tissue disease can be fatal; a careful follow-up is required.

[A case of limbic encephalitis with small cell lung carcinoma in which the cognitive function improved and redeteriorated during tumor therapy].

We report the findings regarding a 70-year-old man with paraneoplastic limbic encephalitis. He presented with a chief complaint of inability to recall any events. He had been well until one month before admission, and then he abruptly began to show progressive amnesia. At admission, the patient's score on the Revised Hasegawa Dementia Scale (HDS-R) showed a decline to 13/30, thus indicating the existence of severe disorientation and an impaired memory. The brain CT and EEG showed no specific abnormalities and an analysis of cerebrospinal fluid showed only a mild increase in the total protein level. A chest X-ray film revealed a mass in the right hilum, while a histological analysis of the biopsied specimen finally established a diagnosis of small cell lung carcinoma. The FDG-PET and the enhanced brain MRI showed a single small metastatic lesion in the cerebellum. After the 1st course of chemotherapy and whole brain radiation, cognitive function, especially the short-term memory, remarkably improved and the HDS-R score increased to 21/30. However, the tumor again increased in size during the 3(rd) and 4(th) courses of chemotherapy. Interestingly, cognitive function also worsened again and the score of HDS-R declined to 15/30, 20 weeks after the start of chemotherapy. Limbic encephalitis can be associated with malignant tumors, such as small cell lung carcinoma, and some reported cases have shown a cognitive improvement after tumor therapy. In our case, we also observed a reworsening of the cognitive function in association with the acquired chemoresistence.