Shunji Matsubara

Angiographic changes in venous drainage of cavernous sinus dural arteriovenous fistulae after palliative transarterial embolization or observational management: a proposed stage classification.

OBJECTIVE:We assessed whether angiographic changes in venous drainage patterns occur over time in cavernous sinus dural arteriovenous fistulae (dAVFs) without a complete cure. METHODS:We classified 65 cavernous sinus dAVFs into three types on the basis of initial angiographic findings. In Type 1, both anterior and posterior drainage routes were open; in Type 2, the posterior drainage route was closed, whereas the anterior drainage route was open; and in Type 3, both the posterior and anterior drainage routes were closed. RESULTS:Of the 65 dAVFs, 40 were of Type 1, 21 of Type 2, and 4 of Type 3. During the follow-up period, 17 of the dAVFs that were treated palliatively with transarterial embolization (n = 11) or monitored without therapy (n = 6) demonstrated angiographic changes. In these 11 patients, there was a change in the venous drainage pattern from Type 1 to Type 2 (n = 5), from Type 2 to Type 3 (n = 3), and from Type 1 to Type 3 (n = 3). One of 11 had a conversion into a lesion with cortical venous drainage. The remaining 6 dAVFs (4 with observational management, 2 with transarterial embolization) demonstrated closure of the fistula; in 5 of these, the affected cavernous sinus was not depicted on follow-up angiograms. CONCLUSION:In some cavernous sinus dAVFs with palliative transarterial embolization or observational management, there was a change in the venous drainage patterns, consisting of a decrease in the number of venous drainage routes. There was a trend for the posterior route to close before the anterior drainage or cortical drainage route. This suggests the occurrence of a staged progression in a regular direction in cavernous sinus dAVFs. Without treatment aiming at a complete cure, most cavernous sinus dAVFs can behave benignly, with a low possibility of development of cortical venous reflux during follow-up.

Ischemic Findings of T2*-Weighted 3-Tesla MRI in Acute Stroke Patients

Background: We compared ischemic findings on gradient echo-type T2*-weighted images at 3-tesla MRI (T2*WI) in patients with acute ischemia and major vessel occlusion, and stroke patients with lacunar infarction or branch atheromatous disease. Methods: Our study population consisted of 45 patients with acute stroke. They underwent 3-tesla MRI within 12 h of stroke onset. Included were 24 patients (13 men and 11 women, mean age 68 years) with major vessel occlusion and 21 patients (11 men and 10 women, mean age 69 years) with minor infarction such as lacunar infarcts or branch atheromatous disease. We classified vascular ischemic findings of T2*WI into 3 sign categories, i.e. artery susceptibility sign, cortical vessel sign (hypointensity and enlargement of the cortical vessels) and brush sign (hypointensity of vessels in the deep white matter). Decreased intensity in the ischemic parenchyma was designated ischemic tissue sign. We compared regions of interest in the hypoperfused area on flow-sensitive alternating inversion recovery (FAIR) images with our vascular ischemic findings. Results: None of the vascular ischemic signs nor the ischemic tissue sign were found in patients with minor vessel disease. All 24 patients with major vessel occlusion manifested the cortical vessel sign, 23 the brush sign. The area with ischemic vessel signs on T2*WI was almost as large or somewhat smaller than the hypoperfused area on FAIR images. Compared to the contralateral side, 14 of 24 patients (58.3%) with major vessel occlusion showed decreased intensity in the ischemic parenchyma (ischemic tissue sign). Region of interest measurements on FAIR images demonstrated greater hypoperfusion in the area classified as ischemic tissue sign on T2*WI. Conclusions: Ischemic vessel signs and the ischemic tissue sign on T2*WI at 3 T would be useful to evaluate the extensive ischemia due to major vessel occlusion and may be correlated with the blood-oxygen-level-dependent effect due to increased deoxyhemoglobin. The ischemic tissue sign may be reflective of severe ischemia.

Can diffusion- and perfusion-weighted magnetic resonance imaging evaluate the efficacy of acute thrombolysis in patients with internal carotid artery or middle cerebral artery occlusion?

OBJECTIVE The value of combined diffusion-weighted imaging (DWI) and perfusion-weighted imaging (PWI) for detecting ischemic lesions of patients with acute ischemic injury was analyzed. Combined pre- and posttreatment DWI and PWI studies were used to assess the efficacy of intra-arterial thrombolysis. METHODS Intra-arterial thrombolysis was performed within 6 hours of onset in 10 patients who presented with acute middle cerebral artery or internal carotid artery occlusion. DWI and PWI obtained before and after treatment were studied. The final T2-weighted magnetic resonance scans were obtained 1 month after onset. Thrombolysis resulted in recanalization in seven patients. The mismatch ratio percentage ([initial PWI − initial DWI/initial PWI] × 100) and the rescued ratio percentage ([initial PWI − final T2/initial PWI] × 100) were calculated. The National Institutes of Health Stroke Scale (NIHSS) was used for neurological assessment of stroke severity at admission and at 1 month after onset. RESULTS In all patients, the mismatch ratio was greater than 60% (mean ± standard deviation, 81.7 ± 16.7%) and was significantly correlated with initial NIHSS score (−0.74;P = 0.03), and the rescued ratio was significantly correlated with the NIHSS score 1 month after the insult (r = −0.83;P = 0.01). In patients who exhibited recanalization of the occluded artery (n = 7), the mean rescued ratio was 89.6 ± 12.8% (range, 63–100%). In addition, the lesion volume on posttreatment DWI scans and final T2-weighted magnetic resonance images was not enlarged; on posttreatment PWI scans, it was significantly decreased. The NHISS score at 1 month after the insult (2.3 ± 2.1) was markedly improved as compared with the initial NHISS score (10.7 ± 3.9). CONCLUSION In a small number of patients who presented with internal carotid artery or middle cerebral artery occlusion, the DWI/PWI mismatch ratio correlated with the initial neurological severity. The rescued ratio may be an objective indicator of the efficacy of treatment.

Analysis of cerebral perfusion and metabolism assessed with positron emission tomography before and after carotid artery stenting. Clinical article.

OBJECT The authors analyzed cerebral perfusion and metabolism in patients with internal carotid artery stenosis before and after carotid artery stenting (CAS). METHODS Sixteen patients with internal carotid artery stenosis (>70%) underwent PET scanning before CAS, 1-7 days after CAS, and 3-4 months after CAS to assess a variety of parameters related to cerebral perfusion and metabolism. RESULTS Cerebral blood flow at rest (CBFrest) significantly increased in the immediate postoperative stage before returning to normal levels over the long term; this trend was also recognized on the contralateral side. In contrast, there was gradual improvement in the rate of CBF variation on acetazolamide administration (% CBFaz). Cerebral perfusion pressure (CBF/cerebral blood volume) increased rapidly during the acute stage and decreased in the long term, and the oxygen extraction fraction decreased slightly during the acute stage before normalizing over the long term. The cerebral metabolic rate of oxygen (CMRO2) increased slightly after stenting over both the short and long term. The ratios of ipsilateral to contralateral values (asymmetry index) for CBFrest, % CBFaz, cerebral blood volume, oxygen extraction fraction, and CMRO2 tended to approach 1.0 over time. CONCLUSIONS Repeated PET scanning revealed improvements in CBF, perfusion pressure, and oxygen metabolism after CAS. In particular, the vascular reserve tended to improve gradually, while CBF, cerebral perfusion pressure, and CMRO2 increased rapidly and peaked soon after CAS. These results suggest that a large discrepancy between rapidly increased CBF, perfusion pressure, and a small increase in vascular reserve in the acute stage after CAS could cause hyperperfusion syndrome.

ELAPSS score for prediction of risk of growth of unruptured intracranial aneurysms.

Objective: To develop a risk score that estimates 3-year and 5-year absolute risks for aneurysm growth. Methods: From 10 cohorts of patients with unruptured intracranial aneurysms and follow-up imaging, we pooled individual data on sex, population, age, hypertension, history of subarachnoid hemorrhage, and aneurysm location, size, aspect ratio, and shape but not on smoking during follow-up and family history of intracranial aneurysms in 1,507 patients with 1,909 unruptured intracranial aneurysms and used aneurysm growth as outcome. With aneurysm-based multivariable Cox regression analysis, we determined predictors for aneurysm growth, which were presented as a risk score to calculate 3-year and 5-year risks for aneurysm growth by risk factor status. Results: Aneurysm growth occurred in 257 patients (17%) and 267 aneurysms (14%) during 5,782 patient-years of follow-up. Predictors for aneurysm growth were earlier subarachnoid hemorrhage, location of the aneurysm, age >60 years, population, size of the aneurysm, and shape of the aneurysm (ELAPSS). The 3-year growth risk ranged from <5% to >42% and the 5-year growth risk from <9% to >60%, depending on the risk factor status. Conclusions: The ELAPSS score consists of 6 easily retrievable predictors and can help physicians in decision making on the need for and timing of follow-up imaging in patients with unruptured intracranial aneurysms.

Does multimodality therapy of arteriovenous malformations improve patient outcome

Abstract The strategy for treating arteriovenous malformations (AVMs) has undergone changes and long-term follow-up results remain unclear. To compare the outcomes of different treatment strategies, we divided 112 patients with 113 AVMs into groups with hemorrhagic (n = 71, 62.8%) and nonhemorrhagic (n = 42, 37.2%) AVMs and subdivided these according to the period in which they were treated (before/after 1990). In the more recent period, treatment more frequently involved the use of the γ-knife and microembolization to the AVM as well as combination therapy. Long-term follow-up showed that the complication rate was lower and the Rankin scale better, in the more recently treated group. Based on our findings we suggest that AVMs should be treated aggressively using a multimodality strategy.

Recent trends in neuroendovascular therapy in Japan: analysis of a nationwide survey--Japanese Registry of Neuroendovascular Therapy (JR-NET) 1 and 2.

The present study retrospectively analyzed the database of the Japanese Registry of Neuroendovascular Therapy 1 and 2 (JR-NET1&2) to determine annual trends, including adverse events and clinical outcomes at 30 days after undergoing neuroendovascular therapy. JR-NET1&2 are surveys that targeted all patients in Japan who underwent neuroendovascular therapy delivered by physicians certified by the Japanese Society of Neuroendovascular Therapy (JSNET) between 2005 and 2009. Medical information about the patients was anonymized and retrospectively registered via a website. Data from 32,608 patients were analyzed. The number of treated patients constantly increased from 5,040 in 2005 to 7,406 in 2009 and the rate of octogenarians increased from 7.0% in 2005 to 10.4% in 2009. The proportion of procedures remained relatively constant, but ratios of angioplasty slightly increased from 32.8% in 2005 to 33.7% in 2009. Procedural complications were associated more frequently with acute stroke (9.6%), ruptured aneurysms (7.4%), intracranial artery disease (ICAD) (5.4%), and arteriovenous malformation (AVM, 5.2%). The number of patients requiring neuroendovascular treatment in Japan is increasing and the outcomes of such therapy are clinically acceptable. Details of each type of treatment will be investigated in sub-analyses of the database.

Acquired pial and dural arteriovenous fistulae following superior sagittal sinus thrombosis in patients with protein S deficiency: a report of two cases.

Two patients with protein S deficiency with acquired multiple pial and dural arteriovenous fistulae (AVFs) following superior sagittal sinus (SSS) thrombosis are reported. Case 1 is a 38-year-old male with protein S deficiency who developed generalized seizure due to SSS thrombosis. Local fibrinolysis was achieved in the acute stage. His 10-month follow-up angiogram revealed an asymptomatic acquired dural AVF arising from the middle meningeal artery and the anterior cerebral artery with drainage to the thrombosed cortical vein in the right frontal lobe. Furthermore, his 2-year follow-up angiogram revealed a de novo pial AVF from the middle cerebral artery in the Sylvian fissure with drainage to the cortical vein initially thrombosed. However, this asymptomatic pial AVF caused bleeding in the ipsilateral cerebral hemisphere 12 years after onset, whereas the dural AVF spontaneously disappeared. Surgical disconnection was successfully performed to eliminate the source of hemorrhage. Case 2 is a 50-year-old male with a past history of SSS thrombosis with protein S deficiency who developed pulsatile tinnitus and generalized seizure. His angiogram showed a cortical dural AVF in the left parietal lobe and a sporadic dural AVF involving the right sigmoid sinus. The parietal lesion was eliminated by transarterial embolization followed by craniotomy. However, a de novo pial AVF emerged from the middle cerebral artery adjacent to the previously treated lesion. Of four cortical AVFs in two patients, thrombosis of cortical veins caused by protein S deficiency might play an important role in their formation. Long-term follow-up is required because this peculiar disorder has an unusual clinical course.

Chronic encapsulated intracerebral hematoma: Three case reports and a literature review

Background: Chronic encapsulated intracerebral hematoma (CEIH) is one type of intracerebral hematoma that sometimes grows progressively while forming a capsule and presenting with neurological deficits. Although many cases of CEIH have been reported, correct preoperative diagnosis is very difficult. Only around 20% of cases are diagnosed preoperatively. Case Description: We encountered three cases of CEIH in which causes were unidentified and difficult to diagnose. All three cases were treated surgically. In the first case, a 59-year-old male was diagnosed preoperatively with metastatic brain tumor. In the second case, a 62-year-old female was diagnosed preoperatively with glioblastoma. The third case involved a 58-year-old female diagnosed preoperatively with CEIH. Conclusion: We should keep in mind that CEIH is a differential diagnosis for intracerebral space-occupying lesions. This report describes these three cases and discusses imaging findings and characteristics of CEIH.

Present epidemiology of chronic subdural hematoma in Japan: analysis of 63,358 cases recorded in a national administrative database

OBJECTIVE Aging of the population may lead to epidemiological changes with respect to chronic subdural hematoma (CSDH). The objectives of this study were to elucidate the current epidemiology and changing trends of CSDH in Japan. The authors analyzed patient information based on reports using a Japanese administrative database associated with the diagnosis procedure combination (DPC) system. METHODS This study included patients with newly diagnosed CSDH who were treated in hospitals participating in the DPC system. The authors collected data from the administrative database on the following clinical and demographic characteristics: patient age, sex, and level of consciousness on admission; treatment procedure; and outcome at discharge. RESULTS A total of 63,358 patients with newly diagnosed CSDH and treated in 1750 DPC participation hospitals were included in this study. Analysis according to patient age showed that the most common age range for these patients was the 9th decade of life (in their 80s). More than half of patients 70 years old or older presented with some kind of disturbance of consciousness. Functional outcomes at discharge were good in 71.6% (modified Rankin Scale [mRS] score 0-2) of cases and poor in 28.4% (mRS score 3-6). The percentage of poor outcomes tended to be higher in elderly patients. Approximately 40% of patients 90 years old or older could not be discharged to home. The overall recurrence rate for CSDH was 13.1%. CONCLUSIONS This study shows a chronological change in the age distribution of CSDH among Japanese patients, which may be affecting the prognosis of this condition. In the aging population of contemporary Japan, patients in their 80s were affected more often than patients in other age categories, and approximately 30% of patients with CSDH required some help at discharge. CSDH thus may no longer have as good a prognosis as had been thought.