Hisaya Hiramatsu

Evaluation of tumor blood flow after feeder embolization in meningiomas by arterial spin-labeling perfusion magnetic resonance imaging.

Preoperative embolization changes the amount of blood flow and pattern of flow distribution in meningioma. Tumor blood flow was investigated in eight meningioma patients before and after embolization using arterial spin-labeling (ASL) perfusion imaging. Although blood flow was significantly reduced in the whole tumor after embolization, changes in flow distribution patterns varied from one case to another. The findings suggest that evaluation of post-embolization tumor blood flow by ASL perfusion imaging would be useful in the surgical planning of meningioma.

Prevention Effect of Antiplatelets on Aneurysm Rupture in a Mouse Intracranial Aneurysm Model

Background and Purpose: Subarachnoid hemorrhage (SAH) from intracranial aneurysm rupture results in significant morbidity and mortality. In the present study, we examined the effect of most widely used antiplatelet drugs, aspirin and cilostazol, on aneurysm rupture prevention using a mouse intracranial aneurysm model. Materials and Methods: Intracranial aneurysms were induced by a combination of deoxycorticosterone acetate-salt and a single injection of elastase into the cerebrospinal fluid in mice. Treatment with aspirin or cilostazol was started 1 day after aneurysm induction. Aneurysm rupture was detected by neurological symptoms and the presence of intracranial aneurysm with SAH was confirmed by post-mortem examination. Results: Aspirin (10 mg/kg) significantly reduced aneurysm rupture (control:aspirin = 80%:31%, p < 0.05) without affecting the overall incidence of aneurysm formation (60%:62%). Cilostazol (3 mg/kg, 30 mg/kg) did not reduce both rupture rate (control:3 mg/kg:30 mg/kg = 81%:67%:77%) and the overall incidence of aneurysm formation (control:3 mg/kg:30 mg/kg = 72%:71%:76%). Tail vein bleeding time prolonged significantly in both aspirin and cilostazol groups (p < 0.01). Conclusion: Aspirin prevented aneurysm rupture in a mouse intracranial aneurysm model, while cilostazol did not. Aspirin, the most frequently used drug for patients with ischemic myocardial and cerebral diseases, is also effective in preventing cerebral aneurysmal rupture.

Cerebellar Hemorrhage due to a Direct Carotid-Cavernous Fistula after Surgery for Maxillary Cancer.

Infratentorial cerebral hemorrhage due to a direct carotid–cavernous fistula (CCF) is very rare. To our knowledge, only four such cases have been reported. Cerebellar hemorrhage due to a direct CCF has not been reported. We describe a 63-year-old female who presented with reduced consciousness 3 days after undergoing a maxillectomy for maxillary cancer. Computed tomography showed a cerebellar hemorrhage. Magnetic resonance angiography showed a left-sided direct CCF draining into the left petrosal and cerebellar veins through the left superior petrosal sinus (SPS). Her previous surgery had sacrificed the pterygoid plexus and facial vein. Increased blood flow and reduced drainage could have led to increased venous pressure in infratentorial veins, including the petrosal and cerebellar veins. The cavernous sinus has several drainage routes, but the SPS is one of the most important routes for infratentorial venous drainage. Stenosis or absence of the posterior segment of the SPS can also result in increased pressure in the cerebellar and pontine veins. We emphasize that a direct CCF with cortical venous reflux should be precisely evaluated to determine the hemodynamic status and venous drainage from the cavernous sinus.

Transvenous Embolization of a Dural Arteriovenous Fistula Involving the Suboccipital Cavernous Sinus

Arnautovic et al. [1] termed the venous structures surrounding the extraspinal segment of the vertebral artery (VA; V3) the suboccipital cavernous sinus (SCS) [1, 4]. We experienced a rare dural arteriovenous fistula (AVF) involving the SCS, which differed from dural AVFs involving the anterior condylar confluence (ACC). Here we present a case of SCS dural AVF with pulsatile tinnitus treated by transvenous embolization (TVE).

Dissecting Aneurysm at the Proximal Segment of the Anterior Cerebral Artery Associated with Infraoptic Course Anterior Cerebral Artery

A 48-year-old man presented a subarachnoid hemorrhage caused by a rupture of a dissecting aneurysm at the proximal segment (A1 segment) of the right anterior cerebral artery (ACA). He also had an anomalous artery named infraoptic course ACA and an agenesis of the contralateral ACA A1 segment. Balloon occlusion test at the bifurcation of the right internal carotid artery demonstrated that the distal segments of the bilateral ACAs were perfused through the infraoptic course ACA. Therefore, we surgically trapped the A1 segment including the aneurysm. The patient got discharged without any neurological deficit. Natural course of ACA dissecting aneurysms is unclear because of rarity of the disease and treatment strategy is still controversial. Most of the dissecting aneurysms in the A1 segment are surgically treated, because they often present with massive hemorrhage and poor prognosis. In the present case, the contralateral A1 segment was absent but trapping of the dissecting aneurysm could be achieved without vascular reconstruction (e.g., bypass surgery) because of the presence of the infraoptic course ACA.

Spontaneous Multiple-Channel Recanalization of Internal Carotid Artery Occlusion with Unusual Radiological Features

A 54-year-old man presented with amaurosis fugax of the right eye and was admitted to our hospital. Magnetic resonance angiography (MrA) revealed occlusion of the right ICA (Fig. 1a), and magnetic resonance imaging (MrI) did not show cerebral infarction. The patient had a history of hyperlipidemia. Atrial fibrillation was not noticed before and during the hospitalization. Intravenous infusions of an antithrombin agent and a perioral antiplatelet agent were administered, and his symptoms disappeared. However, digital subtraction angiography (dsA) performed 10 days after the start of treatment showed right ICA occlusion (Fig. 1b) and collateral flow from the ICA of the opposite side (Fig. 1c). Arterial reconstruction procedures such as superficial temporal artery to middle cerebral artery bypass were not performed because single-photon emission computed tomography studies using [123I]-n-isopropyl-p-iodoamphetamine with and without acetazolamide challenge showed only a slight impairment of the vascular reserve capacity. The patient was discharged from the hospital 2 weeks later without any neural deficits. MRA (3-dimensional [3-D] time-of-flight [TOF] and axial source images) repeated 6 months later revealed recanalization of the right ICA with irregular multiple channels (Fig. 2a and b), without any signs of cerebral infarction or retinal artery occlusion on ophthalmological examinations. The finding of irregular multichannel flow of the right ICA on MRA was observed on dsA performed 2 years later (Fig. 2c and d).

Deep Brain Stimulation for Intractable Obsessive-compulsive Disorder: The International and Japanese Situation/Scenario

Deep brain stimulation (DBS) is used to treat symptoms by modulating the cortico-striato-thalamo-cortical (CSTC) loop in the central nervous system (CNS), and attempts to research loop circuit disorders have been globally initiated among the intractable neurological and psychiatric disorders. DBS treatment has been evaluated for all these newly found CNS loop circuit disorders. In 2011, neurosurgical treatments for psychiatric disorders were renamed from “psychosurgery” to “neurosurgery for psychiatric disorders (NPD)” by the World Society for Stereotactic and Functional Neurosurgery (WSSFN). Moreover, in 2014, “Consensus on guidelines for stereotactic neurosurgery for psychiatric disorders” was published by the WSSFN to address the differences in correspondence of stereotactic NPD. Globally, two multicenter prospective randomized control trials regarding DBS of the subcallosal cingulated gyrus and ventral anterior internal capsule/ventral striatum for intractable depression have been terminated after futility analysis. However, DBS for intractable obsessive-compulsive disorder (OCD), unlike for intractable depression, is showing steady development. In Japan, NPDs have not been performed since 1975 following the adoption of “Resolution of total denial for psychosurgery” by the Japanese Society of Psychiatry and Neurology. Nevertheless, a trend to adopt new neuro-modulation techniques for psychiatric disorders, including DBS, are emerging. We have created a clinical research protocol for the use of DBS in intractable OCD, which has been approved by the ethical committee of Hamamatsu University School of Medicine, with the hope of commencing DBS treatment for intractable OCD patients in the near future.

Dural Arteriovenous Fistula of the Transverse and Sigmoid Sinus Manifesting Ascending Dysesthesia: Case Report and Literature Review

Cases involving intracranial dural arteriovenous fistulas (AVFs) with spinal perimedullary venous drainage exhibit variable presentations, which results in delayed diagnoses. We describe a case of a 66-year-old female with a transverse-sigmoid sinus dural AVF with spinal perimedullary venous drainage who developed dysesthesia and hypalgesia that ascended from the peripheral lower extremities. Sixty cases of intracranial dural AVFs resulting in myelopathy have been reported, and an absence of brainstem signs significantly correlated with a delay in diagnosis (positive group: 3.4 months vs. negative group: 9.6 months, P < 0.05). Intracranial dural AVFs with brainstem signs should be diagnosed without delay because the myelopathy and bulbar symptoms could progress aggressively without alternative drainage routes besides the perimedullary veins. We emphasize that intracranial dural AVFs should be considered as a differential diagnosis in case presenting with symptoms, such as atypical dysesthesia and hypalgesia ascending from the toes, without brainstem signs. Moreover, we should perform cerebral angiography as early as possible because dural AVFs with slow-flow venous drainage can produce false negatives on magnetic resonance angiography.