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ABSTRACT: Background: Vulnerable and inflamed plaques in the carotid artery are at high risk of ischemic stroke, suggesting the importance of diagnostic modalities to detect them in patients with carotid stenosis with high sensitivity and specificity. Although many investigators have reported that magnetic resonance imaging (MRI) is a useful tool to predict the vulnerable components of carotid plaque, its validity is not established. On the other hand, (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) may be an alternative modality to directly identify the inflamed plaque in carotid artery stenosis. Therefore, this study aimed at evaluating the validity of MRI and FDG-PET to predict vulnerable and inflamed carotid plaque. Methods: This prospective study totally included 25 patients who underwent carotid endarterectomy (CEA) for carotid artery stenosis at our institute between January 2009 and January 2012. Prior to CEA, FDG-PET, black-blood T1-weighted imaging (BB-T1WI), and 3-dimensional time-of-flight (TOF) imaging were performed. The specimens were stained with hematoxylin-eosin to assess the different plaque components (lipid, hemorrhage, calcification, and fibrous tissue). In addition, they were stained with primary antibodies against CD68 (activated macrophages) and matrix metalloproteinase (MMP)-9. Results: High FDG uptake was detected in 13 (52.0%) of 25 patients. All of them had lipid-rich plaque. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) to identify the lipid-rich plaques were all 100% for FDG-PET. More importantly, all of the FDG-positive plaques had strong immunoreactivity against both CD68 and MMP-9. There was a significant correlation between the findings on FDG-PET and those on immunohistochemistry against CD68 and MMP-9 (p = 0.006 and 0.004, respectively). On the other hand, 16 (64.0%) of 25 patients had high signal intensity plaque on BB-T1WI. In 7 of these 16 patients, the lesions also showed high signal intensity on TOF imaging. All of them had a large intraplaque hemorrhage. The sensitivity, specificity, PPV, and NPV to identify a large intraplaque hemorrhage were 70, 100, 100, and 83%, respectively, for MRI. Conclusions: These findings suggest that FDG-PET and MRI are complementary to predict high-risk carotid plaque, such as lipid-rich or hemorrhagic plaque. FDG-PET can accurately predict the lipid-rich and inflamed plaque. MRI is valuable to identify unstable plaque with a large intraplaque hemorrhage. The combination of these two modalities may play an important role in predicting carotid plaque at high risk of ischemic stroke.
Cerebrovascular Diseases 04/2013; 35(4):370-377. · 2.72 Impact Factor
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ABSTRACT: We retrospectively investigated surgical immediate and long-term overall results after clipping of the unruptured aneurysms. Between 1991 and 2008, 166 patients underwent neck clipping of unruptured saccular aneurysms at our institute. Patients were subsequently followed to clarify the occurrence of subarachnoid hemorrhage (SAH), and stroke other than SAH, aneurysm recurrence, cerebrovascular death, all-cause death, and risk factors. Surgical complication was noted in 14 patients (8.4 %) and surgical morbidity in two patients (1.2 %). Of 164 patients except for these two patients who suffered surgical morbidity, we could obtain more than 3 years follow-up information for 144 patients (87.8 %). There were 49 men and 95 women. The mean age was 58.5 years, and mean follow-up period was 7.9 years. Eight cases had died during follow-up (hepatic insufficiency in one, renal insufficiency in one, suicide in one, intracerebral hemorrhage (ICH) in two, SAH in one, and pneumonia after stroke in two). Therefore, the cause of death was stroke and late effects of stroke. Twelve symptomatic cerebrovascular events (cerebral infarction in seven, ICH in four, and SAH in one) occurred in ten patients. Consequently, annual risk of SAH after clipping of unruptured aneurysms was 0.085 %. Besides, annual risk of stroke in those patients was 1.06 %, and this incidence was higher than that in the general population. Although this study confirmed the good surgical result, annual risk of stroke after clipping of unruptured aneurysms was much higher than that in the general population. The long-term periodic examination to detect recurrent aneurysms and appropriate management to prevent stroke should be performed for patients with surgically treated unruptured aneurysm.
Neurosurgical Review 04/2013; · 2.04 Impact Factor
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ABSTRACT: 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.
Stroke 12/2012; · 5.73 Impact Factor
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Cerebrovascular Diseases 12/2012; 34(5-6):446-447. · 2.72 Impact Factor
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ABSTRACT: OBJECTIVE: Headache is one of major clinical presentations in pediatric moyamoya disease. However, the clinical features and underlying mechanisms are not fully understood. This study aimed to clarify the clinical feature of headache in pediatric moyamoya disease and the effect of surgical revascularization. METHODS: This study included 29 pediatric patients who underwent superficial temporal artery to middle cerebral artery (STA-MCA) anastomosis and indirect bypass for moyamoya disease. Their medical records were precisely evaluated to identify clinical features of their headache. The findings on MRI, SPECT, and PET were also analyzed. RESULTS: Preoperative headache was documented in 11 (38%) of 29 patients. Majority of them complained of severe headache in the frontal or temporal region in the morning. Headache was significantly related to more advanced disease stage and to the decreases in cerebral blood flow and its reactivity to acetazolamide. Surgical revascularization completely resolved headache in all 11 patients. CONCLUSION: These findings strongly suggest that disturbed cerebral hemodynamics may play key roles to develop severe headache in pediatric moyamoya disease. STA-MCA anastomosis and EDMAPS may be effective procedures to rapidly resolve their headache by widely supplying collateral blood flow to the operated hemispheres.
World Neurosurgery 09/2012; · 0.68 Impact Factor
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ABSTRACT: Isolated abducens nerve palsies associated with the rupture of intracranial aneurysms have rarely been reported. We report two cases of isolated bilateral abducens nerve palsies occurring after subarachnoid hemorrhage due to the rupture of an intracranial aneurysm. Case 1: A 49-year-old woman had bilateral abducens nerve palsies following subarachnoid hemorrhage due to the rupture of the left vertebral artery-posterior inferior cerebellar artery aneurysm. Case 2: A 55-year-old man had bilateral abducens nerve palsies following subarachnoid hemorrhage due to dissecting aneurysm of the right vertebral artery. Case 1 and 2 were treated with surgical clipping of the aneurysm and internal occlusion of the parent artery. In both cases, bilateral abducens nerve palsies achieved almost full recovery several months after treatment. It is speculated that the main causes of palsies are compression and stretching of the bilateral abducens nerves by a thick clot in the prepontine cistern. Although most of the abducens palsies may be reversible and have good prognosis, it is important that they are kept in mind as isolated symptoms of subarachnoid hemorrhage.
No shinkei geka. Neurological surgery 08/2012; 40(8):717-22. · 0.13 Impact Factor
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ABSTRACT: Although a large number of patients with unruptured middle cerebral artery (MCA) aneurysms (AN) have been treated by surgical clipping in Japan, there has yet been no comprehensive study investigating the surgical risks based on a quantitative evaluation of the extensive existing body of patient records. This systematic review was conducted to determine morbidity of the procedure by performing a meta-analysis of the literature. The authors used a PubMed and J-stage search from 2000 to 2011 for studies containing the surgical clipping of the unruptured MCA AN. There were 21 articles, containing a total 1,323 cases of unruptured AN with morbidity specifically located in the MCA. 54 cases indicated significant neurological deficits for a morbidity rate of 4.1% (95% CI; 3.0-5.1). A limited number of studies disclosed an incremental increase in morbidity with the size of the aneurysm. Smaller MCA AN (7±3 mm) presented a lower morbidity of 1.48%, whereas giant MCA AN (>25 mm) corresponded with a higher morbidity of 27.8%. Factors consistently associated with high morbidity included incorporated MCA branches, plaque at the neck of the AN, an unclippable configuration, and M1 superior wall AN. Complex aneurysms required a wide array of intracranial bypass procedures, yielding morbidity of 23.4% (95% CI; 20.9-25.9). This is the first systematic review and quantitative meta-analysis of the surgical complications related to unruptured MCA AN.
No shinkei geka. Neurological surgery 08/2012; 40(8):731-40. · 0.13 Impact Factor
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ABSTRACT: In Japan, a large number of surgical treatments for unruptured intracranial aneurysms have been performed. On the other hands, it is known that surgical treatment for unruptured intracranial aneurysms is the most frequent source of lawsuits in the neurosurgical field. Neurosurgeons have the duty to disclose all risks and consequences of a proposed surgical procedure to each patient. Moreover, precise knowledge of surgical risks would be helpful in preventing complications from occurring. However, it is almost impossible that a single surgeon or an institute have experiences with all possible surgical complications because there is limitation of the number of surgery. In this review series, we attempted an exhaustive bibliographic survey of the possible surgical complications including exceptional ones, and then, determined the frequency of each complications as far as possible quantitatively. In this paper, we focused on the complications of surgical treatment for anterior cerebral artery aneurysms.
No shinkei geka. Neurological surgery 06/2012; 40(6):555-65. · 0.13 Impact Factor
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ABSTRACT: The authors reported a subclavian artery stenting (SAS) using gadolinium contrast medium. The patient was a 65-year-old female who presented dizziness and right upper extremity pain with movement. Digital subtraction angiography revealed right subclavian artery occlusion with subclavian steal phenomenon. We tried to treat this lesion using SAS. However, iodinated contrast medium caused the allergy in this patient and the treatment was discontinued. Therefore, SAS was performed with gadolinium contrast medium. Using gadolinium contrast medium, it is possible to confirm large arteries like innominate artery and subclavian artery. The stenting procedure was performed without complication. The usage of gadolinium contrast medium has the limit and some strategies are important to reduce the usage of gadolinium contrast medium in SAS. First, PercuSurge GuardWire® was placed in the right internal carotid artery to confirm the anatomy, to decide working angle, and to treat the common carotid artery in case of dissection. Second, a "U" shaped guide wire was placed in the distal end from the brachial artery. Guide wire from femoral side was able to pass the lesion at midpoint of the "U" shaped one. SAS using gadolinium contrast medium may be an alternative treatment if a patient with subclavian artery stenosis or occlusion is allergic to iodinated contrast medium.
No shinkei geka. Neurological surgery 05/2012; 40(5):415-20. · 0.13 Impact Factor
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No shinkei geka. Neurological surgery 04/2012; 40(4):365-75. · 0.13 Impact Factor
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Clinical neurology and neurosurgery 03/2012; 114(9):1274-6. · 1.30 Impact Factor
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ABSTRACT: This study was aimed to assess whether bone marrow stromal cells (BMSC) could ameliorate brain damage when transplanted into the brain of stroke-prone spontaneously hypertensive rats (SHR-SP). The BMSC or vehicle was stereotactically engrafted into the striatum of male SHR-SP at 8 weeks of age. Daily loading with 0.5% NaCl-containing water was started from 9 weeks. MRIs and histological analysis were performed at 11 and 12 weeks, respectively. Wistar-Kyoto rats were employed as the control. As a result, T2-weighted images demonstrated neither cerebral infarct nor intracerebral hemorrhage, but identified abnormal dilatation of the lateral ventricles in SHR-SP. HE staining demonstrated selective neuronal injury in their neocortices. Double fluorescence immunohistochemistry revealed that they had a decreased density of the collagen IV-positive microvessels and a decreased number of the microvessels with normal integrity between basement membrane and astrocyte end-feet. BMSC transplantation significantly ameliorated the ventricular dilatation and the breakdown of neurovascular integrity. These findings strongly suggest that long-lasting hypertension may primarily damage neurovascular integrity and neurons, leading to tissue atrophy and ventricular dilatation prior to the occurrence of cerebral stroke. The BMSC may ameliorate these damaging processes when directly transplanted into the brain, opening the possibility of prophylactic medicine to prevent microvascular and parenchymal-damaging processes in hypertensive patients at higher risk for cerebral stroke.
Neuropathology 01/2012; 32(5):522-33. · 2.02 Impact Factor
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ABSTRACT: Research on moyamoya disease has progressed remarkably in the past several decades. Indeed, many new facts concerning the epidemiology of the disease have been revealed and surgical treatments have been drastically improved. However, despite extensive research, the mechanism of moyamoya disease is still unknown. Consequently, the cardinal treatment of this disease has not yet been developed. For further clarification of its etiology, innovative studies are therefore indispensable. The aim of this paper is to review research on the pathogenesis of moyamoya disease to identify milestones in the direction of its true solution. Many hypotheses of the pathogenesis of moyamoya disease have been proposed in the past half century, including infection (viral and bacterial), autoimmune disorders, proteins abnormality, and gene abnormality. Some of these are now considered to be historical achievements. Others, however, can be still subjected to contemporary research. Currently, several genetic abnormalities are considered to offer the most probable hypothesis. In addition, interesting papers have been presented on the role of the endothelial progenitor cell on the pathogenesis of moyamoya disease. Intuitively, however, it appears that a single theory cannot always explain the pathogenesis of this disease adequately. In other words, the complex mechanism of several factors may comprehensively explain the formation of moyamoya disease. The "double hit hypothesis" is probably the best explanation for the complicated pathology and epidemiology of this disease.
Neurologia medico-chirurgica 01/2012; 52(5):267-77. · 0.61 Impact Factor
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ABSTRACT: Crossed cerebellar diaschisis (CCD) often occurs after ischemic or hemorrhagic stroke that damages the cortico-ponto-cerebellar pathway. However, CCD due to cerebral hyperperfusion following cerebrovascular reconstruction is rare. A 61-year-old woman presented with transient CCD due to cerebral hyperperfusion following bypass surgery for adult moyamoya disease. She developed transient weakness of the right extremities and was diagnosed with moyamoya disease. First, she underwent superficial temporal artery to middle cerebral artery (STA-MCA) anastomosis with indirect synangiosis on the left. Postoperative course was uneventful. Subsequently, she underwent STA-MCA anastomosis with indirect synangiosis on the right. She complained of mild headache on the right, and single photon emission computed tomography (SPECT) performed on the 7th postoperative day demonstrated hyperperfusion in the right frontal and temporal lobes associated with hypoperfusion in the left cerebellum. Magnetic resonance (MR) imaging demonstrated no new lesions and MR angiography showed patent STA-MCA bypass. Subsequent SPECT showed disappearance of both hyperperfusion and CCD. This case strongly suggests that cerebral hyperperfusion after bypass surgery for moyamoya disease may cause transient CCD. Although the clinical significance is still obscure, this phenomenon indicates the cortico-ponto-cerebellar pathway is interrupted due to hyperperfusion, suggesting the development of hyperperfusion syndrome. Careful observation of cerebral hemodynamics after bypass surgery is warranted to avoid hyperperfusion-related complications.
Neurologia medico-chirurgica 01/2012; 52(5):350-3. · 0.61 Impact Factor
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ABSTRACT: Spontaneous echo contrast (SEC) consists of numerous microechoes swirling in the cardiovascular lumen and is usually seen during blood stasis in dysfunctional left atrium. However, SEC and consecutive local thrombus formation at the carotid artery early after carotid endarterectomy (CEA) have not been reported. This study retrospectively investigated the clinical importance and therapeutic strategy of postoperative SEC and thrombus formation in 113 consecutive patients who underwent CEA between 2001 and 2009. Ultrasonography was routinely performed preoperatively, intraoperatively, and 1 day and 1 week after the operation. If SEC and/or thrombus was detected at any time after the operation, follow-up ultrasonography was performed at short intervals, once a week for inpatients and once every 1-2 months for outpatients. Eight of the 113 patients (7%) had SEC after the operation from Day 1 to 12 (mean 7.2 days), and 6 of these 8 patients developed local de novo thrombus formation at the site of SEC from Day 6 to 33 (mean 14.7 days). The maximum luminal narrowing by the thrombi were 26-62% (mean 37%). After administering anticoagulant therapy, all thrombi disappeared from Day 13 to 190 (mean 57 days) from CEA. SEC seen after CEA is highly associated with consecutive local thrombus formation. Postoperative geometric blood stasis with the absence of intima may be the causative factor for its development.
Neurologia medico-chirurgica 01/2012; 52(12):885-91. · 0.61 Impact Factor
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ABSTRACT: A 28-year-old woman presented with an unusual case of giant thrombosed varix with calcified walls that had mass effects secondary to a pial single-channel arteriovenous fistula (AVF) associated with hereditary hemorrhagic telangiectasia (HHT). She consulted our hospital for chronic headache. She had been diagnosed with HHT based on genetic testing when her 3-year-old son presented with subarachnoid hemorrhage due to spinal AVF. Imaging studies revealed pial single-channel AVF with multiple varices. The varices in the right frontal lobe were over 6 cm in diameter and had laminar thromboses and calcified walls. Because of the mass effect, direct surgical flow disconnection was performed followed by removal of the varices using an internal decompression technique. Postoperatively, the patient was discharged with no neurological symptoms and no longer suffered chronic headache. Intracerebral varices are occasionally associated with high-flow AVF, and usually treated by interrupting the feeding arteries leaving the varices intact. This extremely rare case of intracerebral giant thrombosed varices with calcified wall and mass effect indicates that surgical removal of varices should be considered.
Neurologia medico-chirurgica 01/2012; 52(7):506-9. · 0.61 Impact Factor
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Yusuke Shimoda,
Satoshi Kuroda,
Daina Kashiwazaki,
Takeshi Asano,
Ken-ichiro Yamashita,
Masahiko Taniguchi,
Tomomi Suzuki,
Tsuyoshi Shimamura,
Hiroyuki Furukawa, Naoki Nakayama,
Kiyohiro Houkin
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ABSTRACT: In this report, the authors describe a 35-year-old male whose intracranial arteriovenous malformation (AVM) spontaneously disappeared about 2 years after successful living-donor liver transplantation for alcohol-induced liver cirrhosis. Preoperative screening MRI revealed intracranial arteriovenous malformation (AVM) around the midbrain. Cerebral angiography demonstrated that the AVM was fed by the paramedian mesencephalic arteries and was drained via the vein of Galen. He successfully underwent living-donor liver transplantation, and his postoperative course was uneventful. Follow-up MRI and MRA revealed spontaneous disappearance of the AVM 27 months after surgery. The authors discuss precisely the underlying mechanism of this rare phenomenon, based on thorough literature review.
No shinkei geka. Neurological surgery 06/2011; 39(6):589-94. · 0.13 Impact Factor
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ABSTRACT: Fungal infection is an increasing problem in patients treated with intensive chemotherapy or immunosuppressive therapy. Of these, invasive aspergillosis or mucormycosis on rare occasions, infiltrate the internal carotid artery (ICA) by contiguous spread from an infected paranasal sinus. Here, we report three cases of ICA infiltration secondary to the fungal infections of the paranasal sinus. All cases developed orbital apex syndrome when the lesion spread to the orbital apex or cavernous sinus, and aggressive progression led to ICA invasion causing life-threatening cerebral infarction or hemorrhage. In this case report, we describe the aggressive clinical course of the fungal ICA invasion from the paranasal sinus, and then discuss the clinical feature, diagnostic methods, and current treatment of intracranial fungal infection.
No shinkei geka. Neurological surgery 02/2011; 39(2):155-61. · 0.13 Impact Factor
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ABSTRACT: The authors present the case of a 61-year-old male with a de novo fusiform vertebral artery aneurysm, probably due to non-traumatic dissection. He underwent flow diversion therapy, using a double overlapping technique, because the origin of the contralateral vertebral artery was stenotic. Placement of two stents resulted in marked reduction of blood flow in the aneurysm. Postoperative course was uneventful. Follow-up 3D-CT angiography revealed a patent blood flow in the stent and a gradual progression of intra-aneurysmal thrombosis. Flow diversion therapy can potentially obliterate the complicated cerebral aneurysm with the preservation of blood flow in the parent artery, and would be one of the important therapeutic options in patients with complicated aneurysms in which conventional strategies such as neck clipping, endovascular coiling and parent artery occlusion are not feasible or contraindicated.
No shinkei geka. Neurological surgery 01/2011; 39(1):59-63. · 0.13 Impact Factor
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ABSTRACT: A 47-year-old male presented with asymptomatic mild (45%) internal carotid artery (ICA) stenosis associated with familial hypercholesterolemia. Fluorine-18-fluorodeoxyglucose ([(18)F]FDG) positron emission tomography (PET) showed that the carotid plaque had high uptake of [(18)F]FDG on the initial scan. He was treated with antiplatelet agent, but subsequently developed retinal artery occlusion on the ipsilateral side. The patient safely underwent carotid endarterectomy (CEA). Histological examination revealed that the plaque was rich in lipids and activated macrophages. Previous large randomized clinical trials have clarified that CEA is an effective therapeutic option to reduce the risk for subsequent ischemic stroke in patients with severe (more than 70%) ICA stenosis. The case strongly suggests that [(18)F]FDG PET may be a useful modality to identify inflamed and/or vulnerable carotid plaque and may be useful to predict the risk for subsequent ischemic stroke even in patients with mild to moderate ICA stenosis (less than 70%).
Neurologia medico-chirurgica 01/2011; 51(10):720-3. · 0.61 Impact Factor
