Takuya Nakazawa

Dissecting aneurysm of the anterior cerebral artery: Report of two cases

Two cases of spontaneous dissecting aneurysm localized to the anterior cerebral artery are reported. Both patients experienced severe headaches, followed by symptoms of cerebral ischemia. In the first case, the dissecting aneurysm showed an angiographic appearance resembling a saccular aneurysm of the anterior communicating artery, and the diagnosis of dissecting aneurysm was confirmed at operation. The second case was treated conservatively, and the diagnosis was reached by repeat angiographic studies.

Solitary intracranial chondroma of the convexity dura: case report

We present a rare case of chondroma originated from the dura mater of the cerebral convexity in a 16-year-old girl. Radiologic findings are reported with emphasis on computed tomography and magnetic resonance imaging scans, and histogenesis is briefly discussed.

Cerebral hemodynamics in patients with normal pressure hydrocephalus: Correlation between cerebral circulation time and dementia

Regional cerebral blood flow and regional cerebral circulation time were measured in 13 demented patients with chronic hydrocephalus, mostly normal pressure hydrocephalus. The average hemispheric, frontal, and temporal cerebral blood flows were significantly reduced. The average regional cerebral circulation time values were significantly prolonged in the frontal, temporal, and thalamic regions, most markedly in the frontal white matter, where periventricular lucency was observed on computed tomography. Clinical improvement was obtained in all patients after operation. While postoperative regional cerebral blood flow values did not change compared with preoperative ones, postoperative regional cerebral circulation time values were significantly reduced in all the regions measured, and most markedly in the frontal white matter. The present results suggest that microcirculation in the frontal lobe is closely correlated with dementia in association with pressure exerted on the nerve fibers in the frontal white matter in patients with normal pressure hydrocephalus.

p53 accumulation and apoptosis in embolized meningiomas

Abstract Preoperative embolization of meningiomas is performed to decrease blood loss at surgery. While it is also expected to reduce tumor recurrence by producing necrosis at the site of dural attachment, very little has been described about what happens to the non-necrotic tumor cells. We investigated how the proliferative activities of meningiomas were modified after embolization. In nine meningiomas which were embolized preoperatively, proliferative potentials and expression of cell cycle inhibitors were assessed immunohistochemically using MIB-1, anti-p53 (DO-1 and DO-7), and anti-p21 (WAF1/CIP1) monoclonal antibodies. To determine whether a cell underwent apoptotic death besides necrosis, we applied the terminal deoxynucleotidyl transferase-mediated dUTP-digoxigenin nick end labeling method. Results were compared with control meningiomas without embolization. MIB-1-positive cells often gathered in perinecrotic areas, although the mean MIB-1 staining index of the embolized meningiomas was not significantly different from the control. p53 and its downstream effector p21 accumulated mainly in the perinecrotic areas in eight of the nine embolized meningiomas. Apoptosis was also observed in the concomitant areas. Double staining for both MIB-1 and p21 frequently showed positive cells for both antibodies. The accumulation of MIB-1-positive cells in the embolized meningiomas may not be a sign of fast growth or malignancy, but it may implicate arrest of cell cycle by the p21. This study indicates that embolized meningiomas exhibit not only necrosis but also apoptosis and cell cycle arrest. The latter effects appear to be at least partly p53 dependent.

Alteration ofbcl-2 andbax expression in embolized meningiomas

We examined the expression of thep53 andbcl-2 family in embolized meningiomas and investigated the interaction between them.p53 and its downstream effectorp21 accumulated mainly in perinecrotic areas, where apoptosis was also observed.bcl-2 was often expressed in the areas distant from necrosis, whereasBax was immunostained more intensely in the perinecrotic areas. Double staining for bothp53 andBcl-2 showed a reciprocal pattern. This appeared to be due to the down-regulation ofBcl-2 byp53. However, regulation ofBax byp53 was not distinct. The expression ofp21 was not apparent 13 days after embolization, and apoptosis was observed until 6 days after embolization. The effect of embolization was most likely temporary, although growth arrest has been reported to persist for a long time in a limited number of embolized cases.

Haemangioblastoma with multiple dural arterial supply: case report

SummaryA case of primary haemangioblastoma with a marked blood supply from multiple meningeal branches of the internal and external carotid arteries is reported, and the clinical implication of detailed angiographic study of unusual feeders in this highly vascular tumour is discussed.

Treatment of spontaneous intradural vertebral artery dissections.

Spontaneous intradural vertebral artery dissections may cause subarachnoid hemorrhage and often result in devastating damage. Increased use of noninvasive imaging studies has allowed larger numbers of patients to be diagnosed. In addition, intracranial vertebral artery dissection tends to induce multiple lesions affecting both intracranial vertebral arteries recurrently. Although unruptured dissections in this area usually have a benign nature, some authors have reported on the incidence of rupture from this lesion. Once hemorrhage from a dissecting vessel wall has occurred, it needs to be treated in the acute phase because of the high risk of rebleeding resulting in high morbidity and mortality. From December 2004 to July 2010, we managed 47 patients with spontaneous vertebral artery dissection, 31 patients were ruptured and 16 were unruptured. All patients who suffered from subarachnoid hemorrhage were treated with endovascular procedures. Most of the patients with unruptured dissection received medical therapy, but if the aneurysmal dilatation persisted or grew, surgical interventions were performed. Stenting with or without coils was deployed for 13 patients with posterior inferior cerebellar artery involvement at the site of dissection and/or were affected on the dominant side. In some patients, stenting was performed even if they were in the acute phase. For other ruptured patients, internal coil trappings were performed. Six patients died due to severe initial subarachnoid hemorrhage and one patient, who underwent stent deployment with coils for the dominant vertebral artery, with bilateral dissection continuing to the basilar artery died due to rerupture while the next additional coiling was planning. There were two cases of complications related to the intervention. During the follow-up period no bleeding occurred in any of the patients except for the previously mentioned patient. In conclusion, internal coil trapping or stent placement with or without coils was effective in preventing rebleeding of ruptured vertebral artery dissection. If the dissection is unruptured, it is necessary to detect the risk of bleeding with careful watching and when progress appears to be made, patients should be treated promptly. Stent-assisted therapy for preserving the patency of the parent artery and major branches is a promising treatment for vertebral artery dissection, even in the acute stage of subarachnoid hemorrhage. However, the risk of acute rerupture and recurrence remains even with the porous stent placement with or without coils.

Hydrocephalus after Aneurysmal Subarachnoid Hemorrhage

Diagnosis of hydrocephalus after aneurysmal subarachnoid hemorrhage has been facilitated by CT, but the true incidence and pathogenesis of the condition remain to be clarified. Extent of ventricular dilatation does not necessarily correlate with clinical symptoms and the indication of shunting operation is by no means definite. Consecutive 117 patients with ruptured aneurysm were retrospectively studied for possible factor(s) for development of hydrocephalus in the chronic stage. The incidence of chronic hydrocephalus was found to be high in those patients with aneurysm of the anterior communicating artery, those harboring acute hydrocephalus, those admitted with higher clinical grades, those showing thick clots and gyral enhancement on initial CT, and those who received tranexamic acid in excess of 30 g.

Endovascular embolization of branch-incorporated cerebral aneurysms

Objectives The aim of this study was to examine the feasibility, technique, and clinical and angiographic outcomes of endovascular coiling to treat a cerebral aneurysm with a branch incorporated into the aneurysmal wall. Methods From 2012 to 2016, 25 patients with 26 cerebral aneurysms having a branch incorporated into the aneurysm (9 unruptured, 17 ruptured) were treated to prevent rupture or re-bleeding from the sac while preserving the incorporated branch by using single-catheter (n = 18), balloon-remodeling (n = 4), stent-assisted coiling (n = 3), or double-catheter (n = 1) techniques. Results Endovascular coiling was conducted in 26 procedures without angiographic occlusion of the incorporated branch. Post-embolization angiography revealed near-complete occlusion (n = 8; 30.7%), neck remnant (n = 13; 50%), and incomplete occlusion (n = 5; 19.3%) aneurysms. Thromboembolisms were observed in four (15.4%) patients during or after the procedure. A procedure-related neurological deficit was observed in one (3.8%) patient. When patients with a preictal modified Rankin Scale (mRS) score of 3 presenting with grade 5 subarachnoid hemorrhage were excluded, all patients had favorable outcomes (mRS 0–2). Six (23.1%) recurrent aneurysms were observed during follow-up, five of which were treated endovascularly at 5–22 months without complication. The location of an aneurysm at the ICA-posterior communicating artery associated with the dominant-type posterior communicating artery was significantly associated with recurrence (p = 0.041). Conclusions Cerebral aneurysms with an incorporated branch were safely treated using conventional endovascular coiling. However, treatment durability was unsatisfactory, especially for dominant-type ICA-posterior communicating artery aneurysms.

Surgery of a large paraclinoid aneurysm with the support of coil embolization.

An attempt was made to clip the neck of a large paraclinoid aneurysm with the support of a balloon catheter, using a trapping-evacuation technique. The clip applied to the neck slipped off because of blood pressure through the posterior communicating artery which arose from the dome of the aneurysm. Therefore, using portable digital subtraction angiography (DSA) equipment, we placed interlocking detachable coils (IDCs) in the aneurysm for the purpose of reducing the intraaneurysmal pressure. Although the aneurysm was eventually trapped with two clips, this case indicates the supportive role of intravascular intervention in aneurysmal surgery when clipping an aneurysm or immediately after clip failure.