Daina Kashiwazaki

Size ratio can highly predict rupture risk in intracranial small (<5 mm) aneurysms.

Background and Purpose— Management strategies for unruptured intracranial aneurysms (UIAs) are controversial. This study aimed to identify surrogate parameters that highly predict the rupture risk of small (<5 mm) UIAs. Methods— Radiological data were collected from 854 patients with aneurysmal subarachnoid hemorrhages who were enrolled in the Sapporo SAH Study. They had a total of 854 ruptured intracranial aneurysms and 180 UIAs. The size, aneurysm-to-vessel size ratio, and distribution were precisely compared between ruptured intracranial aneurysms and UIAs. Results— For all aneurysms, the size was significantly larger in ruptured intracranial aneurysms (7.0±1.3 mm) than in the UIAs (3.7±1.2 mm; P<0.001). Size ratio was also significantly higher in ruptured intracranial aneurysms (4.3±1.9) than in the UIAs (2.2±1.6; P<0.001). Multivariate logistic analysis showed that size and size ratio were correlated with aneurysm rupture. However, in small aneurysms, multivariate logistic regression revealed that only size ratio was associated with ruptured aneurysms (P=0.008; odds ratio, 9.1). There were no significant differences in size or aneurysm location. A receiver operating characteristic analysis was performed for size ratio in small aneurysms, and the threshold separating ruptured and unruptured groups was 3.12 and the area under the curve was 0.801. Conclusions— This study revealed that the size ratio, and not the absolute size, may highly predict the risk of rupture in small UIAs. Size ratio measurements are very simple and provide useful information for determining treatment and follow-up strategies for patients with small UIAs.

Incidence, Locations, and Longitudinal Course of Silent Microbleeds in Moyamoya Disease A Prospective T2*-Weighted MRI Study

Background and Purpose— Clinical significance of silent microbleeds is unknown in moyamoya disease. This study was aimed to clarify the incidence, locations, and longitudinal course. Methods— This prospective cohort study included 78 nontreated patients with moyamoya disease. The incidence and locations of silent microbleeds were evaluated on T2*-weighted MRI. MR examinations were repeated every 6 or 12 months during a mean follow-up period of 43.1 months. Results— T2*-weighted MRI identified silent microbleeds in 17 (29.3%) of 58 adult patients with moyamoya disease, but in none of 20 pediatric patients. During follow-up periods, de novo silent microbleeds developed in 4 (6.9%) of 58 adult patients. Hemorrhagic stroke occurred in 4 patients (6.9%), all of who had silent microbleeds on initial examination. The presence of silent microbleeds was a significant predictor for subsequent hemorrhagic stroke in adult moyamoya disease (P<0.001). Conclusions— Careful and long-term follow-up of silent microbleeds would be essential to improve their outcome in adult patients with moyamoya disease.

Identification of high-risk carotid artery stenosis: motion of intraplaque contents detected using B-mode ultrasonography

OBJECT Identification of the risk of rupture and vulnerability of arterial plaque is not yet clearly understood. The aim of this study was to assess the clinical features of the motion of intraplaque contents (MIC) detected by B-mode ultrasonography. The MIC is characterized by the peculiar movement of the intraplaque contents that is not synchronized with the heartbeat; however, the movement of the carotid artery (CA) wall depends on the heartbeat. METHODS From January 2008 to November 2010, 1798 consecutive patients with transient ischemic attacks (TIAs) or acute ischemic stroke underwent CA ultrasonography for the examination of the MIC. Patients with CA stenosis greater than 50% were followed up until they underwent carotid endarterectomy or CA angioplasty and stent placement. If neither of these procedures were used, the patients were followed up at 90 days. Chi-square and Mann-Whitney tests were performed to compare the categorical and continuous demographic data and risk factors. The effect of the MIC on the rate of recurrent cerebral ischemia was examined using Kaplan-Meier and univariate Cox regression analyses. RESULTS One hundred and fifteen patients had CA stenosis greater than 50%. Among these 115 patients, 58 with a total of 59 CA stenoses had MIC. Twenty-four recurrent ischemic events were associated with MIC, whereas only 6 such events occurred in the absence of MIC. The MIC decreased event-free survival (log-rank test = 15.8, p < 0.001); univariate Cox analysis confirmed that MIC increased the risk of a recurrent ischemic event (HR 5.12, 95% CI 2.08-12.58; p < 0.001). CONCLUSIONS The MIC is one of the findings of vulnerable plaques. The MIC is more useful in predicting the recurrence of TIAs or ischemic events in patients with symptomatic CA stenosis.

Stereotactic neurosurgery for writer's cramp: report of two cases with an overview of the literature.

Background: Writers cramp is a specific movement disorder with hand muscle cramps in writing, being classified into focal and action-specific dystonia. Stereotactic surgery, such as thalamotomy and deep brain stimulation (DBS), has been reported for writers cramp; however, the number of reported cases is still scarce and surgical procedures are also controversial. Objectives: In this study, therefore, we present 2 patients who underwent thalamotomy for writers cramp and systematically review the literature on stereotactic surgery for writers cramp. Methods: Case reports and literature review are presented. Results: Both patients underwent ventral oral nucleus (Vo) thalamotomy safely. Their symptoms completely disappeared after surgery and did not recur during follow-up periods. In the literature, a total of 31 cases were surgically treated for writers cramp. Stereotactic surgery included thalamotomy in 25 cases and DBS in 6. The target included the Vo in 17 cases, the ventral intermediate nucleus (Vim) in 3, and both Vo and Vim in 7. Both procedures markedly improved or resolved the symptoms. Transient neurological deficits were observed in 16.0% of patients after thalamotomy. Conclusions: The Vo may be the most effective target to treat writers cramp. Both thalamotomy and DBS are feasible and effective, but thalamotomy would be a better option, especially in younger or high-risk patients.

Subpial hemangiopericytoma with marked extramedullary growth: case report.

OBJECTIVEHemangiopericytomas, vascular tumors arising in soft tissue, are relatively rare in the central nervous system; they comprise less than 1% of all hemangiopericytomas. Central nervous system hemangiopericytomas occur primarily in the epidural space of the brain and spinal cord. There are no previous reports of subpial, extramedullary growing central nervous system hemangiopericytomas. CLINICAL PRESENTATIONWe document the first case of a subpial hemangiopericytoma with extramedullary growth in the thoracic spine. The patient was a 31-year-old man who developed progressively worsening left lower limb numbness that was followed by gait disturbance over the course of 4 months. INTERVENTIONMagnetic resonance imaging revealed an intradural tumor at the T4–T6 level of the thoracic spine. Because the patients symptoms progressed, he underwent resection of the tumor, which had arisen in the spinal cord subpially without attachment to the dura mater. CONCLUSIONThe pathological diagnosis was hemangiopericytoma. Differential diagnoses include hemangioblastoma, meningioma, schwannoma, and solitary fibrous tumor, the clinical course and prognosis of which are different from hemangiopericytoma. Our experience indicates that hemangiopericytomas can occur as intradural tumors arising from the subpial portion.

Specific Shrinkage of Carotid Forks in Moyamoya Disease: A Novel Key Finding for Diagnosis

This study was aimed to analyze the outer diameter of the involved arteries in moyamoya disease, using three-dimensional (3D) constructive interference in steady state (CISS) and direct surgical inspection. Radiological evaluation was performed in 64 patients with moyamoya disease. As the controls, six patients with severe middle cerebral artery (MCA) stenosis and 17 healthy subjects were also recruited. On 3D-CISS, the outer diameter was quantified in the supraclinoid portion of internal carotid artery (C1), the horizontal portions of MCA (M1) and anterior cerebral artery (A1), and basilar artery. The involved carotid fork was directly observed during surgery in another series of three adult patients with moyamoya disease. In 53 adult patients with moyamoya disease, the outer diameters of C1, M1, and A1 segments were 2.3 ± 0.7 mm, 1.3 ± 0.5 mm, and 1.0 ± 0.4 mm in the involved side (n = 91), being significantly smaller than the control (n = 17), severe M1 stenosis (n = 6), and non-involved side in moyamoya disease (n = 15, P < 0.01). There were significant correlations between Suzuki’s angiographical stage and the outer diameters of C1, M1, and A1 (P < 0.001). The laterality ratio of C1 and M1 was significantly smaller in unilateral moyamoya disease (n = 20) than the controls and severe MCA stenosis (P < 0.01). Direct observations revealed a marked decrease in the outer diameter of the carotid fork (n = 3). These findings strongly suggest specific shrinkage of the involved arteries in moyamoya disease, which may provide essential information to distinguish moyamoya disease from other intracranial arterial stenosis and shed light on the etiology and novel diagnosis cue of moyamoya disease.

Increased expression of vascular endothelial growth factor and its receptor in enlarging brain arteriovenous malformations – a case report

Abstract Case. A 24-year-old man with Spetzler–Martin (S–M) Grade III arteriovenous malformation (AVM). He was conservatively treated, but AVM significantly increased in size over 5 years, judged as Grade IV. Subsequently, he developed intracerebral hemorrhage. AVM was totally removed. Immunohistochemistry showed that the endothelial cells in the dura and nidus were positive for VEGF and VEGF-R.

Effects of Surgical Revascularization on Cerebral Oxygen Metabolism in Patients With Moyamoya Disease: An 15O-Gas Positron Emission Tomographic Study

Background and Purpose— This prospective study was aimed to evaluate the effects of surgical revascularization on cerebral oxygen metabolism in moyamoya disease. Methods— This study included totally 69 hemispheres of 42 patients who underwent superficial temporal artery to middle cerebral artery anastomosis and indirect bypass for moyamoya disease between 2000 and 2011. There were 12 children and 30 adults. MRI and 15O-gas positron emission tomography were performed before and 3 to 4 months after surgery. Hemodynamic and metabolic parameters were precisely quantified and statistically analyzed. Results— Preoperative positron emission tomographic scans revealed that cerebral blood flow was decreased, cerebral blood volume was increased, and cerebral metabolic rate for oxygen was decreased in both pediatric and adult patients. Cerebral metabolic rate for oxygen reduction was observed in ≈80% of pediatric (16/21; 76%) and adult hemispheres (38/48; 79%). Surgical revascularization resolved hemodynamic compromise in all operated hemispheres. Cerebral metabolic rate for oxygen significantly improved in pediatric patients without parenchymal lesions (n=8), but not those with parenchymal lesions (n=8). Multivariate analysis revealed that cerebral metabolic rate for oxygen significantly improved in younger adult patients without parenchymal lesions (P=0.0264; odds ratio, 0.88; 95% confidence interval, 0.79–0.99). Conclusions— Cerebral oxygen metabolism is significantly depressed in ≈80% of the involved hemispheres of moyamoya disease and improves in pediatric and younger adult patients without parenchymal lesions after bypass surgery. Cerebral oxygen metabolism may be reversibly depressed in response to cerebral ischemia in them although the underlying mechanisms are still unclear.

Reversal of Cognitive Dysfunction by Total Removal of a Large Lateral Ventricle Meningioma: A Case Report with Neuropsychological Assessments

Although cognitive impairment is one of the major symptoms of ventricular tumors, few studies have reported the details of cognitive impairment before and after their surgical removal. The expected effects on cognitive function should also be considered when choosing a surgical approach. We report the case of a large lateral ventricle meningioma in which cognitive impairment was detected on detailed neuropsychological examinations. The tumor was totally removed through the right superior temporal gyrus. Postoperative neuropsychological assessment revealed the reversal of cognitive impairment. As cognitive impairment is complex and easily overlooked, it is important to precisely assess neuropsychological function in patients with large brain tumors.

Berlin Grading System Can Stratify the Onset and Predict Perioperative Complications in Adult Moyamoya Disease.

BACKGROUND The grading system for moyamoya disease is not established. OBJECTIVE To assess the usefulness of a recently proposed grading system for stratifying the clinical severity and predicting postoperative morbidity in adult moyamoya disease. METHODS We investigated 176 hemispheres from 89 adult patients who were diagnosed with moyamoya disease in Japan. Their data were analyzed using the Berlin grading system with minor modifications. After summarizing the numerical values for digital subtraction angiography (1-3 points), magnetic resonance imaging (0-1 points), and single-photon emission computed tomography (0-2 points), 3 grades of moyamoya disease were defined: mild (grade I) = 1 to 2 points, moderate (grade II) = 3 to 4 points, and severe (grade III) = 5 to 6 points. In total, 82 of 161 hemispheres underwent superficial temporal artery to middle cerebral artery anastomosis and indirect synangiosis. Postoperative neurological morbidity was included within 30 d after surgery. RESULTS Preoperative examinations categorized 87 hemispheres as grade I, 39 as grade II, and 50 as grade III. There was a significant correlation between the Berlin grading system and clinical severity (P < .001). Perioperative complications occurred in 12 of 82 (14.6%) hemispheres, including transient ischemic attack in 3 hemispheres, ischemic stroke in 4 hemispheres, symptomatic hyperperfusion in 4 hemispheres, and intracerebral hemorrhage in 1 hemisphere. The Berlin grading system was related to their occurrence (P < .001). CONCLUSION The Berlin grading system facilitates the stratification of clinical severity and predicting postoperative neurological morbidity in adult moyamoya disease, thereby suggesting its general usage in clinical practice.