Yuki Ohmori

Strategy for treating unruptured vertebral artery dissecting aneurysms.

BACKGROUND The natural course of unruptured vertebral artery dissecting aneurysms (VADAs) remains unclear. OBJECTIVE The purpose of this retrospective study was to develop a strategy for treating unruptured VADAs based on long-term follow-up. METHODS Our study population consisted of 100 patients with unruptured VADAs; in 66, the initial symptom was headache only, 30 presented with ischemic symptoms and 4 with mass effect. All underwent magnetic resonance imaging and magnetic resonance angiography at the time of admission and 2 weeks and 1, 3, 6, 12, and 24 months after the onset. If the dissection site was demonstrated to be enlarged on magnetic resonance imaging and magnetic resonance angiography without the manifestation of new symptoms, the patients received additional treatment to prevent bleeding. RESULTS Of the 100 patients, 4 underwent early intervention because of symptom exacerbation. The other 96 were initially treated conservatively; during follow-up, 5 manifested lesion enlargement on magnetic resonance angiography. Nine patients received additional treatment; 1 underwent direct surgery with trapping of the dissection site, and 8 underwent coil embolization. The other 91 patients continued to be treated conservatively; the dissection site remained unchanged in 70, improved or healed in 18, and disappeared in 3 patients. We treated 38 patients with recurrent ischemic attacks with antiplatelet therapy. No patients experienced bleeding or permanent neurological deficits during follow-up. CONCLUSION The nature of an unruptured VADA is not highly aggressive. However, if the dissection site enlarges without the manifestation of new symptoms, it should be occluded. In patients with recurrent ischemic attacks antiplatelet therapy should be considered. ABBREVIATIONS MRA: magnetic resonance imaging PICA: posterior inferior cerebellar artery SAH: subarachnoid hemorrhage VA: vertebral artery VADA: vertebral artery dissecting aneurysm

Comparison of Dynamic Contrast-Enhanced 3T MR and 64-Row Multidetector CT Angiography for the Localization of Spinal Dural Arteriovenous Fistulas

BACKGROUND AND PURPOSE: For the localization of spinal dural arteriovenous fistulas, it is not determined whether dynamic contrast-enhanced MRA is more reliable than multidetector CTA. The aim of this study was to compare the agreement between intra-arterial DSA, dynamic contrast-enhanced MRA at 3T, and 64-row multidetector CTA for the localization of spinal dural arteriovenous fistulas. MATERIALS AND METHODS: We enrolled 12 consecutive patients (11 men, 1 woman; age range, 46–83 years; mean, 65 years) who underwent preoperative dynamic contrast-enhanced MRA at 3T and 64-row multidetector CTA. The spinal dural arteriovenous fistula location was confirmed by intra-arterial DSA as the reference standard. Two reviewers independently evaluated the level of the artery feeding the spinal dural arteriovenous fistula on the basis of continuity between the feeder and abnormal spinal vessels on 3T dynamic contrast-enhanced MRA and 64-row multidetector CTA images. Interobserver and intermodality agreement was determined by calculation of the κ coefficient. RESULTS: On DSA, the vessel feeding the spinal dural arteriovenous fistula was the intercostal artery (7 cases), the lumbar artery (3 cases), and the internal iliac artery or the ascending pharyngeal artery (1 case each). For the fistula level, interobserver agreement was excellent for 3T dynamic contrast-enhanced MRA (κ = 0.97; 95% CI, 0.92–1.00) and very good for 64-row multidetector CTA (κ = 0.84; 95% CI, 0.72–0.96). Intermodality agreement with DSA was good for 3T dynamic contrast-enhanced MRA (κ = 0.78; 95% CI, 0.49–1.00) and moderate for 64-row multidetector CTA (κ = 0.41; 95% CI, 0.020–0.84). CONCLUSIONS: For the localization of spinal dural arteriovenous fistulas, 3T dynamic contrast-enhanced MRA may be more reliable than 64-row multidetector CTA.

Reversibility of cognitive disorder after treatment of dural arteriovenous fistulae.

IntroductionDural arteriovenous fistulae (DAVF) occasionally lead to cognitive disorders whose reversibility after DAVF treatment remains unclear. We studied changes on pre- and post-treatment magnetic resonance imaging (MRI) and single photon emission computed tomography (SPECT) scans in ten patients with cognitive disorder due to DAVF.MethodsWe studied the symptoms, pre- and post-treatment MRI scans, SPECT findings, and mini-mental state examination (MMSE) and treatment results in ten patients with cognitive disorder due to DAVF. They were divided into two groups; the post-treatment MMSE score exceeded 25 points in group 1 (n = 6) and was lower than 24 points in group 2 (n = 4).ResultsIn the six group 1 patients, pretreatment diffusion-weighted images (DWI) showed hyperintense areas, and SPECT scans demonstrated the preservation of vasoreactivity after acetazolamide challenge. In the four group 2 patients, pretreatment SPECT demonstrated hypoperfusion areas that coincided with the hyperintense areas seen on DWI; there were areas with marked disturbance in vasoreactivity. The post-treatment MMSE score in groups 1 and 2 improved by 13.7 ± 2.4 and 3.8 ± 1.0 points, respectively; the difference was significant at p < 0.01.ConclusionIn patients with cognitive disorder due to DAVF, the preservation of vasoreactivity on SPECT after acetazolamide challenge indicates that their cognitive disorder may be reversible by DAVF treatment.

Cilostazol improves symptomatic intracranial artery stenosis - Evaluation of cerebral blood flow with single photon emission computed tomography.

Background: To evaluate the effectiveness of cilostazol in patients with intracranial arterial stenosis, we used magnetic resonance angiography (MRA). The drugs effect on the cerebral blood flow (CBF) was examined by single photon emission computed tomography (SPECT). Methods: In this retrospective study, we evaluated the clinical outcomes of 20 patients with stenosis in the M1 segment of the middle cerebral artery (MCA) who had suffered ischemic stroke within 12 weeks or manifested asymptomatic stenosis exceeding 50%. All patients received cilostazol (100 mg twice daily). MRA and SPECT (at rest and after acetazolamide challenge) studies were performed before and 6 and 12 months after the start of cilostazol treatment. Results: In 5 patients the stenotic lesion showed improvement on MRA. Mean stenosis before cilostazol therapy was 71.7 ± 4.9%, which improved to 39.0 ± 3.2% at 6 months and to 27.2 ± 2.8% at 12 months. SPECT study showed that CBF was improved in 3 patients; in one there was improvement at rest and the other 2 manifested improvement upon acetazolamide challenge. Conclusions: Cilostazol had a remodeling effect on stenotic lesions due to arteriosclerotic changes and improved CBF in some patients.

Endoscopic surgical treatment for pituitary apoplexy in three elderly patients over the age of 80

OBJECTIVES As the population continues to live longer, the diagnosis of pituitary adenoma-induced apoplexy becomes more common in the elderly. The standard treatment options for pituitary apoplexy are debatable. Although there is little information regarding the treatment of pituitary apoplexy in elderly patients, the optimal treatment needs to be determined for this age group. The current study examined the surgical treatment of pituitary apoplexy in three patients over the age of 80. CASE DESCRIPTION Three patients over the age of 80 with pituitary apoplexy were admitted to our hospital. Some symptoms caused by pituitary apoplexy, including decreased visual acuity, double vision and oculomotor paresis, had persisted for more than 14 days. Magnetic resonance imaging revealed suprasellar mass lesions extending into the cavernous sinus. The general condition of the patients was good, and we performed endoscopic transsphenoidal surgery in each of these cases. The masses were removed, and the histological findings were diagnosed as non-functioning pituitary adenoma with presence of hemorrhagic or ischemic necrosis. Perioperative courses and general conditions were good, and the neurological deficits of each patient improved immediately. CONCLUSIONS Endoscopic transsphenoidal surgery has the advantage of visualization of the structures surrounding the pituitary gland. Moreover, the complication rate is relatively low because stress on the pituitary gland can be reduced by using this procedure. Even in patients over 80 years of age during the subacute phase, endoscopic surgical management is a good treatment candidate for pituitary apoplexy with mass lesion extension into the cavernous sinus.

Evaluation of Intracranial Arteriovenous Malformations With Four-Dimensional Arterial-Spin Labeling-Based 3-T Magnetic Resonance Angiography.

Objective We aimed to assess the usefulness of 3-T 4-dimensional (4D) arterial spin-labeling (ASL)–based magnetic resonance angiography (MRA) with color-coded time-of-arrival (TOA) maps for the evaluation of cerebral arteriovenous malformations (AVMs). Methods Our study included 6 patients with cerebral AVMs. They underwent 4D-ASL MRA at 3T and digital subtraction angiography. A pseudocontinuous arterial spin labeling protocol with look-locker sampling was used for spin labeling. Two independent readers reviewed the 4D-ASL MRA images with color-coded TOA maps for the nidus size, arterial feeders, and venous drainage. Two other readers consensually reviewed the digital subtraction angiography images. Results The cerebral AVMs were demonstrated on all 4D-ASL MRA images. In 5 high-flow AVMs, the color-coded TOA maps were especially useful for identifying the feeder/drainer. Intermodality agreement was excellent for the nidus size (&kgr; = 1.0), very good for arterial feeders (&kgr; = 0.88), and good for venous drainage (&kgr; = 0.80). Conclusions The 4D-ASL 3-T MRA with color-coded TOA maps is useful for assessing the gross angiographic characteristics of intracranial AVMs.

Prolonged Mean Transit Time Detected by Dynamic Susceptibility Contrast Magnetic Resonance Imaging Predicts Cerebrovascular Reserve Impairment in Patients with Moyamoya Disease

Background: Evaluating cerebrovascular reserve (CVR) is important for patients with moyamoya disease (MMD). 123I-iodoamphetamine single-photon emission CT (SPECT) with acetazolamide (ACZ) challenge is widely carried out, but using ACZ becomes problematic owing to its off-label use and its adverse effects. Here, we report the efficacy of dynamic susceptibility contrast MRI (DSC-MRI) for the evaluation of CVR in MMD patients. Methods: All 33 MMD patients underwent both SPECT and DSC-MRI at an interval of <10 days from each other (mean age 38.3 years). The region of interest (ROI) was the anterior cerebral artery (ACA) territory, middle cerebral artery (MCA) territory, basal ganglia and cerebellum hemisphere for cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) images. The ratios of the ROIs to the ipsilateral cerebellum were calculated for each parameter and evaluated. The CVR was calculated using images acquired by SPECT before and after ACZ administration. The ratios of DSC-MRI parameters and CVR were compared and evaluated for each ROI. Results: The MTT of the ACA and MCA territories significantly correlated with CVR (p < 0.0001). However, CBF and CBV had no correlation with CVR. The MTT ratio had a threshold of 1.966, with a sensitivity of 68.4% and a specificity of 91.5% for predicting decreased CVR (<10%). Conclusion: MTT had a negative correlation with CVR. DSC-MRI is easy, safe and useful for detecting decreased CVR and can be used as a standard examination in MMD patients care.

Granulocyte Colony-Stimulating Factor Enhances the Angiogenetic Effect of Indirect Bypass Surgery for Chronic Cerebral Hypoperfusion in a Rat Model

BACKGROUND:Granulocyte colony-stimulating factor (G-CSF) mobilizes hematopoietic bone marrow cells into systemic circulation and has been used clinically to treat chemotherapy-induced neutropenia. Recently, G-CSF was shown to have neuroprotective and angiogenetic effects in acute cerebral infarction. OBJECTIVE:To evaluate the effects of G-CSF for angiogenesis after indirect bypass surgery. METHODS:Chronic cerebral hypoperfusions were induced in male Wistar rats by permanent bilateral internal carotid artery occlusion (BICAO). After BICAO, unilateral indirect bypass and encephalogaleosynangiosis (EGS) were performed, and human recombinant G-CSF (10 μg/kg) or saline was injected intramuscularly for 5 consecutive days. We measured regional cerebral blood flow (rCBF) by laser Doppler flowmetry and performed immunohistochemical analysis 21 days after BICAO. RESULTS:BICAO decreased rCBF to 62.52% ± 5.8% of control (P < .01). The rCBF increased significantly 21 days after BICAO in all treatment groups (n = 10; P < .05) except the G-E- group. The rCBF increase observed in the G+E+ group was significantly higher than that observed in other groups. Both G-CSF and EGS treatments significantly increased the number of small vessels (P < .01), and G-CSF and EGS showed additive effect in increasing the number of small vessels. CONCLUSION:Combined use of G-CSF and indirect bypass surgery induces an increase in rCBF and angiogenesis under conditions of cerebral chronic hypoperfusion. This is the first report to demonstrate that G-CSF can enhance angiogenesis induced by indirect bypass surgery, and that this combined therapy is a safe and easy method of treatment.

Prolonged and regionally progressive symptomatic cerebral hyperperfusion syndrome after superficial temporal artery-middle cerebral artery anastomosis in a patient with moyamoya disease.

Background: The incidence of symptomatic hyperperfusion syndrome after superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis for patients with moyamoya disease (MMD) approaches 30%. In most cases, hyperperfusion occurs in a localized area and disappears within 1-2 weeks. Case Description: A 59-year-old female diagnosed with asymptomatic MMD for 4 months became rapidly symptomatic with transient ischemic attacks (TIAs). After left STA-MCA anastomosis surgery, she developed symptomatic hyperperfusion, initially (1-2 weeks after surgery) manifesting with severe headache and lesions located in the left basal ganglia. She then developed (2-5 weeks after surgery) aphasia and right hemiparesis caused by new hyperperfusion lesions located in the left frontal area. At discharge (7 weeks after surgery), she recovered fully without any remaining neurologic deficit and no ischemic lesions. Conclusion: This report details a rare case of a patient with MMD who presented with regionally progressive hyperperfusion lesions after STA-MCA anastomosis and symptoms that persisted for 5 weeks following surgery. Results from this case suggest that regional differences exist in the functional recovery of cerebrovascular reactivity (CVR) in a patient with rapidly progressive MMD.

Dissecting aneurysms of the vertebral artery—angiographic patterns at the dissecting site on balloon test occlusion

IntroductionAt present, the risk of future hemorrhage or ischemic insult from vertebral artery (VA) dissection cannot be estimated from available imaging data. We investigated the relationship between symptoms and the angiographic patterns of the dissecting site on balloon test occlusion (BTO) to develop guidelines for clinical decision-making.MethodsWe retrospectively reviewed 18 patients with unilateral VA dissection who presented with subarachnoid hemorrhage (SAH) or cerebral infarction. We analyzed the angiographic findings at the dissecting site on contralateral VA angiograms during BTO of the affected VA, classified the angiographic patterns into two types, and compared the symptoms they presented.ResultsPatients with dissection opacified from the distal to the proximal side are more likely to present with cerebral infarction than SAH. Conversely, patients with dissection opacified from the proximal to the distal side had a significantly higher incidence of SAH.ConclusionsAngiographic findings at the dissecting site on contralateral VA angiograms during BTO of the affected VA are helpful for considering the treatment and prognosis of patients with VA dissecting aneurysms.