Case Report: Deep Cerebellar Stimulation for Tremor and Dystonia

Background: The cerebellum plays an important role in the pathogenesis and pathophysiology of movement disorders, including tremor and dystonia. To date, there have been few reports on deep cerebellar stimulation.

Case Report: The patient was a 35-year-old previously healthy man with no history of movement disorders. He developed a tremor and stiffness in his left hand at the age of 27 years, which was diagnosed as a dystonic tremor. We performed right thalamotomy, which resulted in a complete resolution of the tremor; however, the dystonia persisted. Subsequently, the patient developed left foot dystonia with inversion and a newly developed tremor in the right hand and foot. The patient underwent left ventralis intermedius (VIM) deep brain stimulation (VIM-DBS) and left pallidothalamic tract DBS (PTT-DBS). Left VIM-DBS completely resolved the right hand and foot tremor, and PTT-DBS significantly improved the left hand and foot dystonia. Three months postoperatively, the patient developed an infection and wound disruption at the surgical site. We performed palliative surgery for deep cerebellar stimulation via the posterior cranial region, which was not infected. The surgery was performed under general anesthesia with the patient lying in the prone position. Eight contact DBS electrodes were used. The placement of electrodes extended from the superior cerebellar peduncle to the dentate nucleus. Both the right hand and foot tremor improved with right cerebellar stimulation. Further, both the left hand and foot dystonia improved with left cerebellar stimulation. Right and left cerebellar stimulation led to no improvement in the left hand and foot dystonia and right hand and foot tremor, respectively. Stimulation-induced complications observed in the patient included dizziness, dysphagia, and dysarthria. After the surgery, the patient developed hypersalivation and hyperhidrosis in the left side of the body, both of which did not improve with adjustments of stimulation parameters. At the 6-month follow-up, the tremor and dystonia had almost completely resolved.

Conclusion: Deep cerebellar stimulation deserves consideration as a potential treatment for tremor and dystonia.

Comorbid seizure reduction after pallidothalamic tractotomy for movement disorders: Revival of Jinnai's Forel-H-tomy

Forel-H-tomy for intractable epilepsy was introduced by Dennosuke Jinnai in the 1960s. Recently, Forel-H-tomy was renamed to "pallidothalamic tractotomy" and revived for the treatment of Parkinson's disease and dystonia. Two of our patients with movement disorders and comorbid epilepsy experienced significant seizure reduction after pallidothalamic tractotomy, demonstrating the efficacy of this method. The first was a 29-year-old woman who had temporal lobe epilepsy with focal impaired awareness seizure once every three months and an aura 10-20 times daily, even with four antiseizure medicines. For the treatment of hand dyskinesia, she underwent left pallidothalamic tractotomy and her right-hand dyskinesia significantly improved. Fourteen months later, she had experienced no focal impaired awareness seizure and the aura decreased to one to three times per month. The second case was that of a 15-year-old boy diagnosed with progressive myoclonic epilepsy, who developed generalized tonic-clonic seizure, which manifested once every month, despite treatment with five antiseizure medicines. After surgery, myoclonic movements in his right hand slightly improved. A one-year follow-up revealed that he had not experienced a generalized tonic-clonic seizure. The lesion locations in the two cases were close to the vicinity of Jinnai's Forel-H-tomy. Forel's field H deserves reconsideration as a treatment target for intractable epilepsy.

Precise detection of the germinomatous component of intracranial germ cell tumors of the basal ganglia and thalamus using placental alkaline phosphatase in cerebrospinal fluid

PURPOSE

The disadvantages of biopsy for lesions in the basal ganglia and thalamus include a risk of various complications, difficulty in selecting the target tissue in some cases due to indistinct neuroimaging findings and limited availability of sample tissue. Placental alkaline phosphatase (PLAP) plays a decisive role in the diagnosis and management of intracranial germ cell tumors (IGCTs) in the basal ganglia and thalamus. The present study aimed to demonstrate the ability, specificity, and optimal use of PLAP values obtained from cerebrospinal fluid (CSF).

METHODS

Twenty patients with lesions in the basal ganglia and thalamus were enrolled in this study: 11 had IGCTs and 9 had non-IGCTs. The values of PLAP and other established tumor markers in the CSF were measured in all patients before treatment.

RESULTS

The mean follow-up period was 76.0 months (range, 3-168) for all lesions. PLAP was elevated in all 11 patients with IGCTs in the basal ganglia or thalamus, whereas none of the patients with non-IGCT exhibited elevated PLAP. Thus, the sensitivity and specificity of PLAP were both 100%.

CONCLUSION

Our data demonstrated that the PLAP value can specifically identify the germinomatous component even in cases of IGCTs in the basal ganglia or thalamus with high sensitivity and specificity. PLAP is undoubtedly beneficial for the safe and timely detection of the germinomatous component of IGCTs in the basal ganglia and thalamus, because reliance on PLAP measurement enables us to avoid invasive surgical procedures and facilitates the prompt initiation of chemoradiation therapy.

Prevalence and Screening of Deep Vein Thrombosis in Patients with Osteoporotic Vertebral Fracture e

AIM

This study aimed to determine the prevalence of a deep vein thrombosis (DVT) in osteoporotic vertebral fractures.

MATERIAL AND METHODS

Data were retrospectively collected from the medical records of 50 patients who were admitted to the Kameda Medical Center for osteoporotic vertebral fracture from 2019 to 2020. Inpatients were screened for DVT using D-dimer, and those who were screened positive underwent lower extremity venous ultrasonography to confirm DVT. Associations between various clinical factors and DVT were analyzed.

RESULTS

Six (12.0%) inpatients with osteoporotic vertebral fractures were found to have DVT. Two (33.3%) of the six had proximal DVT, although no pulmonary embolism was detected by chest computed tomography angiography. Univariate analysis showed that D-dimer values and duration from onset to hospitalization were predictive of DVT (P 0.05).

CONCLUSION

The prevalence of DVT among inpatients with osteoporotic vertebral fractures was 12.0%. This finding emphasizes the importance of DVT screening using D-dimer in those with osteoporotic vertebral fractures.

Mucosal thickening of the maxillary sinus is frequently associated with diffuse glioma patients and correlates with poor survival prognosis of GBM patients: comparative analysis to meningioma patients

Glioma patients were frequently associated with mucosal thickening of the maxillary sinus (MTMS), which reflects mucosal inflammation. We suspected that MTMS is associated with impaired mucosal immune response and correlated with dysfunction in the anti-tumor immune response in diffuse glioma patients. Therefore, the aim of this study was to determine whether the occurrence of diffuse glioma is correlated with MTMS compared to meningioma and control groups. Furthermore, we investigated whether MTMS is associated with overall survival (OS) in glioblastoma (GBM) patients. This study included 343 patients with newly diagnosed diffuse gliomas and 218 patients with meningioma treated at our institution between 2015 and 2018. As control, 201 patients with headache who did not have an intracranial organic lesion were included. Using three-axis MR images, we evaluated the incidence of MTMS in all patients. Additionally, we investigated the relationship between MTMS and OS. The incidence of MTMS in patients with diffuse glioma was significantly higher than that in the meningioma (p < .0001) and control groups (p < .0001). In 128 patients with GBM, MTMS status correlated significantly with OS (p = .0064). We revealed that the incidence of MTMS is significantly associated with patients with diffuse glioma. This suggests that MTMS is indirectly involved in the occurrence of diffuse gliomas. Furthermore, the presence of MTMS correlated significantly with shorter OS in GBM patients, indicating that MTMS is involved in suppression of anti-tumor immune response. Preoperative recognition of MTMS might be useful for improving the clinical management of GBM patients.

A case of idiopathic extracranial carotid artery pseudoaneurysm with a rare clinical course and pathological features

Extracranial carotid artery aneurysms (ECAAs) are rare, with the etiology mainly classified as degeneration or dissection. Pseudoaneurysms in the region are even rarer and are seen following trauma, iatrogenic injury, or infection. We report a case of extracranial carotid artery pseudoaneurysm (pseudo-ECAA) with a rare clinical course and pathological features. A 58-year-old man presented with swelling and purpura on the left side of his neck after sneezing. Radiological examinations suggested a ruptured left common carotid artery aneurysm. The operative findings were consistent with a pseudoaneurysm. Pathological examination revealed disarrangement and degeneration of smooth muscle fibers in the media, in addition to scattered foci of mucoid accumulation and irregular-shaped cavitation in the medial extracellular matrix, raising the possibility of an intrinsic dysfunction of the vascular wall in the pathological process of pseudoaneurysm formation.

Long-Term Successful Outcome of Dystonic Head Tremor after Bilateral Deep Brain Stimulation of the Ventral Intermediate and Ventro-Oral Internus Nuclei: A Case Report and Literature Review of Dystonic Head Tremor

Head tremor in patients with dystonia is referred to as dystonic tremor. During surgical treatment, numerous targets may be selected, including the internal segment of the globus pallidus and the ventral intermediate (Vim) nucleus; however, there is no consensus concerning the most effective treatment target. We report herein a case of dystonic head tremor in which improvement persisted for 5 years after deep brain stimulation (DBS) of the bilateral thalamic Vim and ventro-oral internus (Voi) nuclei. The patient, a 67-year-old woman, has a horizontal head tremor associated with cervical dystonia that had been resistant to drug treatment over 3 years. Immediately following surgery, dystonia and tremor symptoms had completely improved. Voice volume declined and dysarthria occurred but improved upon adjusting the stimulation conditions. Over 5 years, both head tremor and cervical dystonia have been completely controlled, and no other obvious complications have been observed. As the Voi nucleus receives pallidothalamic projections involved in dystonia and the Vim nucleus receives cerebellothalamic projections involved in tremors, stimulating these 2 nuclei with the same electrode appears reasonable in the treatment of dystonic tremor. This case suggests that Vim-Voi DBS may be effective for treating dystonic head tremor.

Unilateral pallidotomy in the treatment of cervical dystonia: a retrospective observational study

OBJECTIVE

The objective of this study was to assess the efficacy of unilateral pallidotomy in patients with asymmetrical cervical dystonia.

METHODS

This study retrospectively included 25 consecutive patients with asymmetrical cervical dystonia refractory to botulinum toxin injections, who underwent unilateral pallidotomy between January 2015 and April 2017. Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) scores were evaluated preoperatively and 1 week, 3 months, and 6 months postoperatively. The clinical responses were defined as good responders, exhibiting > 50% improvement in the TWSTRS score at 6 months postsurgery, or poor responders, exhibiting < 50% improvement in TWSTRS scores at 6 months postsurgery.

RESULTS

Twelve and 9 patients showed right- and left-side rotation, respectively; 1 and 3 patients had right- and left-side laterocollis, respectively. The mean age of onset and duration of the disease were 40.2 ± 13.9 and 8.9 ± 10.9 years, respectively. Mean TWSTRS scores were 38.4 ± 12.6 (p < 0.001), 17.3 ± 12.4 (p < 0.001), 19.5 ± 13.4 (p < 0.001), and 20.0 ± 14.7 (p < 0.001), preoperatively and 1 week, 3 months, and 6 months postoperatively, respectively. Fourteen patients (56%) demonstrated > 50% improvement in their TWSTRS total score (mean improvement of TWSTRS total score = 70.5%) 6 months postsurgically. Furthermore, preoperative TWSTRS severity score was a prognostic factor (odds ratio 1.37, 95% confidence interval 1.06-1.78, p = 0.003).

CONCLUSIONS

These results suggest that unilateral pallidotomy is an acceptable treatment option for asymmetrical cervical dystonia. Further investigations with a larger number of cases and longer follow-up period are required to confirm these data.

Diagnosis and Management of Moyamoya Disease

Moyamoya disease is an uncommon vascular disease, which causes obstruction and stenosis of arteries of the circle of Willis, and preferentially affects children and young adults. This disease is seen across the world, but is more common in East Asia. It may cause hemorrhagic or ischemic stroke, or transient ischemic attack. If symptoms or cerebral blood flow become worse, revascularization surgery is recommended. We present 2 cases of moyamoya disease who underwent bypass surgery. We also discuss the epidemiology, pathology, genomics, and symptomatology as well as diagnosis, and management of moyamoya disease.

NI-09 Amide Proton Transfer (APT) image is useful for diagnostic imaging of glioma

Introduction: APT image(APT),which images the concentration of amide groups that increases in tumors, is expected to be applied clinically in diagnostic imaging of glioma. Purpose: APT was compared with MET-PET based on the pathological diagnosis results, and it was retrospectively verified that APT was useful for diagnostic imaging of glioma. Methods: A total of 46cases with glioma (WHO 2016 Grade: GII/III/IV) and Pseudoprogression were included. APT measured the APT measurement value by placing the region of interest in the tumor part. MET-PET was administered with 370MBq and the accumulation ratio(TNR) between the tumor part and the normal part was measured. Results: The APT measurement value in all cases was 2.22±1.01 and the TNR was 2.58±1.50,and a correlation was observed between the APT measurement value and the TNR(r=0.6, p&lt;0.001).When the accuracy of discrimination between GII/III/IV (32cases) and Pseudoprogression(14cases) by APT measurement was verified, the sensitivity was 91% and the specificity was 100% at the threshold of 1.81. In the verification of malignancy diagnosis, the measured APT value of GII (6cases) was 2.18±0.43,the measured APT value of GIII (11cases) was 2.67±0.69,and the measured APT value of GIV (15cases) was 2.99±0.61.The measured value showed a significant difference. The measured APT value in the oligodendroglioma group (GII/III:10cases) was 2.37±0.66,the TNR was 3.52±1.41,and the measured APT value in the astrocytoma group (GII/III: 7cases)Was 2.67±0.45 and TNR was 2.41±0.87.In the oligodendroglioma group, the measured APT value was lower and the TNR was higher than in the astrocytoma group. Conclusion: It was suggested that APT may have the same diagnostic ability as MET-PET in diagnosing malignant tumors and distinguishing between recurrence and Pseudoprogression. Patients with an actual APT of 1.81 or higher should consider treatment strategies, and follow-up may be an option for patients with an APT of &lt;1.81.APT,which is not affected by the blood-brain barrier, has little variation in measured values and is considered to be useful for diagnostic imaging of glioma.

ACT-17 Protocol design of a matrix-type of novel clinical trial for lower-grade gliomas

Introduction: Differentiation between glioma grade 2 and 3 was performed based on histological findings. The current grade is an important prognostic factor due to its widespread use, economic efficiency, and data accumulation, but analog elements remain and the genetic marker is unknown. The concept of Lower-grade glioma including G2/3 is spreading. On the other hand, WHO grade is the criteria of clinical trials, and evidence is established for G2 with low risk and high risk, G3 alone or with G4. In Japan, JCOG 1303 and 1016 have been implemented for high-risk G2 and G3, respectively and will be finished next year. Therefore, we examined the feasibility and design of novel clinical trial for patients with grade 2/3 glioma. Method: With reference to clinical trials of high evidence level and public database registration, we researched trials, arms, and designs for each of 3 genotypes, oligodendroglioma (OD), astrocytoma IDH mutant and IDH wild (A-IDHm, A-IDHw). Results: The standard arm common to all genotypes is follow-up (EORTC22845) for G2 low-risk, and chemoradiotherapy (CRT) for G3. Standard arm for G2 high risk, depending on a genotype, is follow-up (EORTC22845), radiation alone (A-IDHm and IDHw, A-IDHw: RTOG9802 subanalysis), or PCV chemoradiotherapy (OD and A-IDHm: 9802). Furthermore, the standard arm and the test arm were replaced by the matrix-like method on each genotype. Results in the G2/3-targeted trial, there was no standard arm all in the three genotypes. In addition, there were a design of master protocols for many genotype and a design that has arms of randomization and observation. Conclusion: Applying the master protocol, the possibility of novel G2/3 target trial in which the arms existing in MATRIX form was suggested. With the improvement of the genetic analysis infrastructure, prospective observational research and a well-designed intervention research plan for each genotype are required.

ES-1 Clinical results of tumor treating fields in patients with glioblastoma in Japan, compared with global surveillance

INTRODUCTION: The tumor treatment field induces apoptosis of tumor cells by providing a low intensity, intermediate frequency, alternating current electric field via a transducer array. TTFields is based on Phase 3 EF-11 and EF-14 trials for glioblastoma in the US FDA and Japan PMDA. Therefore, I will report the statistics of TTFields use in Japan along with recent papers. METHODS: 410 patients were treated with TTFields in Japan (December 2017-), of which 17 were at Tokyo Women’s Medical University. We also referred to papers about global post-marketing surveillance and recent studies. RESULTS: Of the 410 patients, 409 (99.8%) were diagnosed with ndGBM(male: female, 66.8%: 33.2%). As of June 2020, 222 patients (54.1%) were on treatment and 188 (45.9%) were discontinued. In 17 cases at TWMU, the average age was 46.3 years. The average treatment period was 218 days, with 6 patients (35%) continuing treatment, 6 patients (35%) discontinuing due to patient wishes, and 5 patients (30%) discontinuing treatment due to recurrence. Side effects were contact dermatitis under the array in 9 patients (57%) and mild malaise in 7 patients (43%). We experienced long-term progression-free cases with TTF use of 25 months (survival 30 months after surgery) with a glioma partially resected and 21 months (survival 27 months after surgery) with a biopsied glioma. In the biopsy case, bevacizumab was used in combination during the treatment. Conclusion: In global surveillance, use for rGBM accounts for 39%, but Japan is limited to use for ndGBM due to insurance coverage. In terms of side effects, it showed a good safety profile comparable to previous trials. Long-term progression-free cases have been observed, and it is necessary to examine the characteristics of patients who respond to treatment and the effect of concomitant use with bevacizumab by prospective studies

[Advantages and Pitfalls of the Lateral Supraorbital Approach as Less Invasive Surgery for Unruptured Anterior Circulation Aneurysms]

The lateral supraorbital approach(LSOA)is widely accepted as a less invasive surgical technique compared with the conventional pterional approach(PA). However, only a few studies have reported less invasiveness associated with LSOA. To evaluate this issue, we retrospectively investigated the surgical outcomes in 133 patients who underwent LSOA and 28 patients who underwent PA for unruptured anterior circulation aneurysms. We analyzed operation time, postoperative symptoms and complications, and the length of postoperative hospitalization(in days)for each method. All aneurysms were successfully clipped regardless of the approach. The operation time was significantly shorter, the postoperative headache rate was lower, resumption of oral intake was more rapid, and length of hospitalization was shorter in the LSOA group. Statistical significance was not observed in the postoperative complication rates. Compared with conventional PA, LSOA was associated with less invasiveness and better patient satisfaction. LSOA is a safe and effective alternative to conventional PA, following optimal patient selection.

NIMG-08. PREDICTION OF LOWER-GRADE GLIOMA MOLECULAR SUBTYPES USING DEEP LEARNING

INTRODUCTION

It is useful to know the molecular subtype of lower-grade gliomas (LGG) when deciding on a treatment strategy. This study aims to diagnose this preoperatively.

METHODS

A deep learning model was developed to predict the 3-group molecular subtype using multimodal data including magnetic resonance imaging (MRI), positron emission tomography (PET), and computed tomography (CT). The performance was evaluated using leave-one-out cross validation with a dataset containing information from 217 LGG patients.

RESULTS

The model performed best when the dataset contained MRI, PET, and CT data. The model could predict the molecular subtype with an accuracy of 96.6% for the training dataset and 68.7% for the test dataset. The model achieved test accuracies of 58.5%, 60.4%, and 59.4% when the dataset contained only MRI, MRI and PET, and MRI and CT data, respectively. The conventional method used to predict mutations in the isocitrate dehydrogenase (IDH) gene and the codeletion of chromosome arms 1p and 19q (1p/19q) sequentially had an overall accuracy of 65.9%. This is 2.8 percent point lower than the proposed method, which predicts the 3-group molecular subtype directly. CONCLUSIONS AND FUTURE

PERSPECTIVE

A deep learning model was developed to diagnose the molecular subtype preoperatively based on multi-modality data in order to predict the 3-group classification directly. Cross-validation showed that the proposed model had an overall accuracy of 68.7% for the test dataset. This is the first model to double the expected value for a 3-group classification problem, when predicting the LGG molecular subtype. We plan to apply the techniques of heat map and/or segmentation for an increase in prediction accuracy.

Pre-Therapeutic Factors Predicting for the Necessity of Rescue Treatments in Mechanical Thrombectomy

Objective

Mechanical thrombectomy for acute large vessel occlusion (LVO) is currently widely performed. However, rescue treatment (RT), such as percutaneous transluminal angioplasty (PTA) and stenting, is occasionally required, particularly in the case of atherothrombotic brain infarction (ATBI) or dissection. As RT requires higher levels of therapeutic skills and additional devices, early prediction of its performance and preparation are important. We retrospectively investigated the pre-therapeutic factors for predicting the necessity of RT.

Methods

We reviewed 149 consecutive patients who underwent mechanical thrombectomy for acute LVO between April 2014 and December 2019. Eight patients were excluded because of missing clinical data. RT was performed when severe stenosis was observed in occluded vessels or proximal to them during mechanical thrombectomy. We investigated pre-therapeutic neurological, laboratory, and radiological findings in the 141 remaining patients, and compared them between RT and non-RT groups.

Results

RT was performed on 23 of the 141 patients. We found four pre-therapeutic factors with significantly different rates between RT/non-RT as follows: (1) Atrial fibrillation 8.7%/71.1% (p <0.001), (2) diabetes mellitus 39.1%/19.5% (p = 0.04), (3) susceptibility vessel sign (SVS) by T2-weighted imaging 17.4%/66.1% (p <0.001), and (4) tapered occlusion by magnetic resonance angiography (MRA) 47.8%/11.9% (p <0.001). The plasma level of brain natriuretic peptide (BNP) was also significantly different between the two groups. When the BNP level was less than 70 pg/mL, the sensitivity for being in the RT group was 86.9% and the specificity was 83.5%.

Conclusion

Pre-therapeutic findings, such as diabetes mellitus, tapered occlusion, absence of atrial fibrillation, negative SVS, and BNP level less than 70 pg/mL, are predictors of RT in mechanical thrombectomy.

Nonconvulsive status epilepticus after surgery for ruptured intracranial aneurysms: Incidence, associated factors, and impact on the outcome

OBJECTIVE

To evaluate the incidence of nonconvulsive status epilepticus (NCSE) after surgery for ruptured intracranial aneurysms, to define factors associated with this complication, and to determine its impact on the outcome.

PATIENTS AND METHODS

Clinical and neurophysiological data of 66 patients with aneurysmal subarachnoid hemorrhage (aSAH) who underwent continuous EEG (cEEG) monitoring after microsurgical clipping (53 cases) or endovascular coiling (13 cases) of the ruptured aneurysm were analyzed retrospectively. The diagnosis of NCSE was based on the American Clinical Neurophysiology Society and Salzburg Consensus criteria.

RESULTS

NCSE was revealed in 10 patients (15 %), all of whom underwent craniotomy and aneurysm clipping. In comparison to the subgroup without NCSE, among those who were diagnosed with this complication there was a significantly greater proportion of men (70 % vs. 34 %; P = 0.041), cases with the Glasgow Coma Scale score at admission < 13 (90 % vs. 36 %; P = 0.004), the Hunt and Hess aSAH grades 3-5 (90 % vs. 45 %; P = 0.013), and hydrocephalus (70 % vs. 29 %; P = 0.044). In addition, they required a significantly longer hospital stay (medians, 62.5 vs. 39.5 days; P = 0.015) and showed trend for the lower rate of favorable disability outcomes (20 % vs. 54 %; P = 0.084).

CONCLUSIONS

NCSE is encountered rather often after the microsurgical clipping of ruptured intracranial aneurysms, especially in severely disabled patients with high-grade aSAH and/or associated hydrocpephalus, and may significantly affect the clinical course and prolong recovery. cEEG monitoring may be helpful for timely diagnosis and treatment of this complication.

Direct double bypass using the posterior auricular artery as initial surgery for moyamoya disease: technical note

Surgical treatments for moyamoya disease (MMD) include direct revascularization procedures with proven efficacy, for example, superficial temporal artery (STA) to middle cerebral artery (MCA) bypass, STA to anterior cerebral artery bypass, occipital artery (OA) to MCA bypass, or OA to posterior cerebral artery bypass. In cases with poor development of the parietal branch of the STA, the posterior auricular artery (PAA) is often developed and can be used as the bypass donor artery. In this report, the authors describe double direct bypass performed using only the PAA as the donor in the initial surgery for MMD.In the authors' institution, MMD is routinely treated with an STA-MCA double bypass. Some patients, however, have poor STA development, and in these cases the PAA is used as the donor artery. The authors report the use of the PAA in the treatment of 4 MMD patients at their institution from 2013 to 2016. In all 4 cases, a double direct bypass was performed, with transposition of the PAA as the donor artery. Good patency was confirmed in all cases via intraoperative indocyanine green angiography and postoperative MRA or cerebral angiography. The mean blood flow measurement during surgery was 58 ml/min. No patients suffered a stroke after revascularization surgery.

Spinal cord infarction six months after thoracic endovascular aortic repair- A case report

Spinal cord infarction is reported to account for less than 1% of all strokes and is a relatively rare disease. In recent years, thoracic endovascular aortic repair (TEVAR) has become a common treatment for aortic aneurysms, and spinal cord ischemia is one of its complications. Most cases occur in the perioperative period; however, a few cases have been reported in the chronic stage. Here, we report a case of spinal cord infarction, 6 months after TEVAR. A 77-year-old man experienced sudden onset paraparesis following dumbbell exercises and defecation. He had a history of an infectious thoracoabdominal aortic aneurysm treated by TEVAR 6 months prior. Paralysis and disturbance of the thermal pain and tactile sensations of the lower limbs were observed, but proprioception and deep sensation were preserved. Computed tomography (CT) showed no evidence of intraspinal hemorrhage, new aortic dissection, or endoleak around the aortic stent placed from Th11 to L3. Magnetic resonance imaging (MRI) showed intramedullary hyperintensity from Th11 to the conus 2 days after onset. Anticoagulant therapy and rehabilitation were performed, and the lower-limb muscle strength gradually improved. After aortic stenting, particularly including the level of the Adamkiewicz artery, the risk of spinal cord ischemia must be monitored, because spinal circulation depends on collateral circulation.

Encoding of social exploration by neural ensembles in the insular cortex

The insular cortex (IC) participates in diverse complex brain functions, including social function, yet their cellular bases remain to be fully understood. Using microendoscopic calcium imaging of the agranular insular cortex (AI) in mice interacting with freely moving and restrained social targets, we identified 2 subsets of AI neurons—a larger fraction of “Social-ON” cells and a smaller fraction of “Social-OFF” cells—that change their activity in opposite directions during social exploration. Social-ON cells included those that represented social investigation independent of location and consisted of multiple subsets, each of which was preferentially active during exploration under a particular behavioral state or with a particular target of physical contact. These results uncover a previously unknown function of AI neurons that may act to monitor the ongoing status of social exploration while an animal interacts with unfamiliar conspecifics.

The insular cortex participates in diverse complex brain functions, including social function, but their cellular basis remains unclear. This study uses microendoscopic calcium imaging in mice interacting with conspecifics to identify “social cells” in the agranular insular cortex; multiple subsets of neurons encode distinct aspects of ongoing social behavior.

Mechanical thrombectomy in acute ischemic stroke patients with left ventricular assist device

OBJECTIVES

As the number of patients with left ventricular assist device (LVAD) implantation has been increasing, treatment of LVAD-related ischemic stroke is becoming a critical issue. We sought to clarify the features of mechanical thrombectomy in LVAD-related stroke with large vessel occlusion.

METHODS

In a multi-center, retrospective case-control study, we compared 20 LVAD-related strokes with 33 non-LVAD strokes, all of which had large vessel occlusion in the anterior circulation treated with mechanical thrombectomy. A comparative histopathological examination of the retrieved thrombi was also performed.

RESULTS

Successful reperfusion was achieved in 75% of the LVAD-related strokes. The time from onset to reperfusion was similar to that of non-LVAD strokes, but the total number of device passes required for reperfusion (median, 2.5 versus 1, P = 0.01) and the incidences of post-procedural parenchymal and subarachnoid hemorrhage (25% versus 3%, P = 0.02 and 55% versus 15%, P = 0.01, respectively) were higher in LVAD-related strokes. Symptomatic intracranial hemorrhage occurred in 4 patients (20%) with LVAD-related strokes. The histopathological analysis revealed that the ratio of erythrocyte components was significantly lower in thrombi retrieved from patients with LVAD-related stroke than in those with non-LVAD stroke (19 ± 6% versus 41 ± 17%, P = 0.01).

CONCLUSIONS

Mechanical thrombectomy is feasible in patients with LVAD-related stroke. However, repetitive device passes are needed to achieve successful reperfusion mainly because of the structurally organized thrombi, and the higher risk of hemorrhagic complications should be considered, while offering this therapeutic alternative.

Radiofrequency ablation for DYT-28 dystonia: short term follow-up of three adult cases

Mutations in the lysine methyltransferase 2B (KMT2B) gene have recently been reported to be associated with childhood‐onset generalized dystonia. There have been no studies investigating ablative treatments for the management of this disorder. Three patients underwent either a staged unilateral pallidotomy and contralateral pallidothalamic tractotomy (19‐year‐old man, 2‐year follow‐up), a unilateral pallidothalamic tractotomy (34‐year‐old man, 6‐month follow‐up) or a simultaneous unilateral pallidothalamic tractotomy and ventro‐oral thalamotomy (29‐year‐old man, 6‐month follow‐up). The average total patient score on the Burke‐Fahn‐Marsden Dystonia Rating Scale‐Movement Scale improved from 39.5 to 13.2 (66.6%) after the procedures. No significant complications were identified. Ablative treatments appear to be a promising alternative surgical option for generalized dystonia with KMT2B mutation.

Vasa vasorum formation is associated with rupture of intracranial aneurysms

OBJECTIVE

Subarachnoid hemorrhage (SAH) has a poor outcome despite modern advancements in medical care. The development of a novel therapeutic strategy to prevent rupture of intracranial aneurysms (IAs) or a novel diagnostic marker to predict rupture-prone lesions is thus mandatory. Therefore, in the present study, the authors established a rat model in which IAs spontaneously rupture and examined this model to clarify histopathological features associated with rupture of lesions.

METHODS

Female Sprague Dawley rats were subjected to bilateral ovariectomy; the ligation of the left common carotid, the right external carotid, and the right pterygopalatine arteries; induced systemic hypertension; and the administration of a lysyl oxidase inhibitor.

RESULTS

Aneurysmal SAH occurred in one-third of manipulated animals and the locations of ruptured IAs were exclusively at a posterior or anterior communicating artery (PCoA/ACoA). Histopathological examination using ruptured IAs, rupture-prone IAs induced at a PCoA or ACoA, and IAs induced at an anterior cerebral artery-olfactory artery bifurcation that never ruptured revealed the formation of vasa vasorum as an event associated with rupture of IAs.

CONCLUSIONS

The authors propose the contribution of a structural change in an adventitia, i.e., vasa vasorum formation, to the rupture of IAs. Findings from this study provide important insights about the pathogenesis of IAs.

[A Case of a Massive Retropharyngeal Hematoma Associated with Traumatic Cervical Cord Injury]

Retropharyngeal hematomas are uncommon, but they may rarely cause occlusion of the upper airway and threaten life. Retropharyngeal hematomas often occur due to head or neck injury;they rarely occur due to iatrogenic causes such as insertion of a gastric tube or anticoagulant therapy. It has been found that patients receiving anticoagulant therapy are more likely to experience potentially severe retropharyngeal hematomas. We report the case of a patient with retropharyngeal hematoma with cervical cord damage. A 75-year-old man was transferred to our hospital after he sustained a fall and damaged his face. CT showed a massive retropharyngeal hematoma, but he did not complain of any breathing issues. Therefore, we selected conservative therapy. However, after approximately 4 hours, he suddenly complained of breathing problems and suffered from loss of consciousness. We performed intubation and provided sedation. After one week, his condition clearly improved and he was extubated.