Impact of areal socioeconomic status on prehospital delay of acute ischaemic stroke: retrospective cohort study from a prefecture-wide survey in Japan.

OBJECTIVES: To examine whether the Areal Deprivation Index (ADI), an indicator of the socioeconomic status of the community the patient resides in, is associated with delayed arrival at the hospital and poor outcomes in patients with acute ischaemic stroke from a prefecture-wide stroke database in Japan. DESIGN: Retrospective study. SETTING: Twenty-nine acute stroke hospitals in Kochi prefecture, Japan. PARTICIPANTS: Nine thousand and six hundred fifty-one patients with acute ischaemic stroke who were urgently hospitalised, identified using the Kochi Acute Stroke Survey of Onset registry. Capital and non-capital areas were analysed separately. PRIMARY AND SECONDARY OUTCOME MEASURES: Prehospital delay defined as hospital arrival ≥4-hour after stroke onset, poor hospital outcomes (in-hospital mortality and discharge to a nursing facility) and the opportunities of intravenous recombinant tissue plasminogen activator (rt-PA) and endovascular reperfusion therapy. RESULTS: In the overall cohort, prehospital delay was observed in 6373 (66%) patients. Among individuals residing in non-capital areas, those living in municipalities with higher ADI (more deprived) carried a significantly higher risk of prehospital delay (per one-point increase, OR (95% CI) 1.45 (1.26 to 1.66)) by multivariable logistic regression analysis. In-hospital mortality (1.45 (1.02 to 2.06)), discharge to a nursing facility (1.31 (1.03 to 1.66)), and delayed candidate arrival ≥2-hour of intravenous rt-PA (2.04 (1.30 to 3.26)) and endovascular reperfusion therapy (2.27 (1.06 to 5.00)), were more likely to be observed in the deprived areas with higher ADI. In the capital areas, postal-code-ADI was not associated with prehospital delay (0.97 (0.66 to 1.41)). CONCLUSIONS: Living in socioeconomically disadvantaged municipalities was associated with prehospital delays of acute ischaemic stroke in non-capital areas in Kochi prefecture, Japan. Poorer outcomes of those patients may be caused by delayed treatment of intravenous rt-PA and endovascular reperfusion therapy. Further studies are necessary to determine social risk factors in the capital areas. TRIAL REGISTRATION NUMBER: This article is linked to a clinical trial to UMIN000050189, No.: R000057166 and relates to its Result stage.

Quantitative evaluation for intravascular structures of vertebral artery dissection with a novel zoomed high-resolution black-blood MR imaging.

BACKGROUND: Although non-stroke vertebral artery dissection (VAD) is diagnosed using MRI, detecting the subtle intravascular structure remains challenging. This study aimed to evaluate the validity of quantitative intravascular scanning based on novel zoomed high-resolution black blood (Z-HB) MRI for distinguishing VAD from other vessel pathologies. METHODS: Twenty-one patients with non-stroke VAD and 18 with symptomatic atherosclerotic plaques in their vertebral artery underwent Z-HB MRI and subsequent profile curve processing. Axial Z-HB imaging was obtained from dissected and normal segments in patients with VAD and atherosclerotic plaque in patients with ischemia. We investigated the qualitative categorization of the scanning patterns of the intravascular signals. We also evaluated the quantitative ability of each profile curve to discriminate multiple vessel pathologies by analyzing the receiver operating characteristics curves. RESULTS: Profile curve processing of 140 Z-HB images categorized the intravascular signal patterns into luminal, asymmetrical, and omega types. The asymmetrical type included both dissecting and atherosclerotic vessels, and the omega type included dissecting and normal vessels. In the asymmetrical type, quantitative evaluation successfully distinguished intramural hematomas of VAD from atherosclerotic plaque with an area under the curve of 0.80. The intimal flap of the VAD was distinguished from the blood flow artifact of the normal vessel with an area under the curve of 0.93 in the omega type. CONCLUSIONS: A combination of novel Z-HB MRI and profile curve processing provided an ultra-high-resolution analysis of the intravascular structure of non-stroke VAD and successfully distinguished VAD from normal vessels or atherosclerotic plaques.

Gamma Knife Radiosurgery for Metastatic Brain Tumors from Uterine Cervical and Endometrial Carcinomas: Histopathological Analysis of Survival and Local Control. A Japanese Multi-Institutional Cooperative and Retrospective Cohort Study.

OBJECTIVE: A retrospective comparative analysis of the outcomes of gamma knife radiosurgery (GKRS) for brain metastases from uterine cervical carcinoma (CC) and endometrial carcinoma (EC), investigated the efficacy and prognostic factors for survival and local tumor control. Histopathological analysis was also performed. METHODS: The authors retrospectively reviewed 61 patients with 260 tumors of CC and 73 patients with 302 tumors of EC who had undergone GKRS. RESULTS: The survival times after GKRS had no difference between CC and EC. Uncontrolled primary cancer was significant unfavorable factor. CC resulted in significantly higher neurological death and post-GKRS neurological deterioration. New lesions appeared intracranially after GKRS, with no significant difference between CC and EC. Local tumor control rates at 6, 12, and 24 months after GKRS were 90.0%, 86.6%, and 78.0% for CC and 92.2%, 87.9%, and 86.4% for EC. Primary cancer of CC, more than 7 cm3 volume, and prescription dose less than 20 Gy were significantly correlated in control failure. Local tumor control rates were significantly lower for squamous cell carcinoma in CC. No significant differences were found between histopathological subtypes of EC. CONCLUSIONS: This study established a relationship between the efficacy of GKRS for CC and EC brain metastases and the histopathological. Though, survival time after GKRS has no difference between CC and EC, CC was significantly higher neurogenic death and neurological deterioration after GKRS. Squamous cell carcinoma had a significantly lower rate of local tumor control among all CC, thereby resulting in CC having lower local tumor control than EC.

Gamma Knife radiosurgery for metastatic brain tumors from ovarian cancer: histopathological analysis of survival and local control. A Japanese multi-institutional cooperative and retrospective cohort study.

OBJECTIVE: Brain metastasis is rare in ovarian cancer patients. The results of Gamma Knife radiosurgery (GKRS) for the treatment of patients with brain metastases from ovarian cancer were retrospectively analyzed to derive the efficacy and prognostic factors for survival and local tumor control. Further histopathological analysis was also performed. METHODS: The authors retrospectively reviewed the medical records of 118 patients with 566 tumors who had undergone GKRS at the 10 GKRS institutions in Japan. RESULTS: After the initial GKRS, the median overall survival time was 18.1 months. Multivariate analysis showed that uncontrolled primary cancer (p = 0.003) and multiple intracranial metastases (p = 0.034) were significant unfavorable factors. Ten patients died of uncontrolled brain metastases at a median of 17.1 months. The 6-, 12-, and 24-month neurological death rates were 3.2%, 4.6%, and 11.9%, respectively. The 6-, 12-, and 24-month neurological deterioration rates were 7.2%, 13.5%, and 31.4%, respectively. The 6-, 12-, and 24-month distant brain control failure rates were 20.6%, 40.2%, and 42.3%, respectively. Median tumor volume was 1.6 cm3 and marginal dose was 20 Gy. The 6-, 12-, and 24-month local tumor control rates were 97.6%, 95.2%, and 88.0%, respectively. Peritumoral edema (p = 0.043), more than 7-cm3 volume (p = 0.021), and prescription dose less than 18 Gy (p = 0.014) were factors that were significantly correlated in local tumor control failure. Eight patients had symptomatic radiation injury. The 6-, 12-, and 24-month GKRS-related complication rates were 3.3%, 7.8%, and 12.2%, respectively. Primary ovarian cancer was histopathologically diagnosed for 313 tumors in 69 patients. Serous adenocarcinoma was found in 37 patients and other types in 32 patients. Median survival times were 32.3 months for the serous type and 17.4 months for other types after initial GKRS. Patients with serous-type tumors survived significantly longer than patients with other types (p = 0.039). The 6-, 12-, and 24-month local tumor control rates were 100%, 98.8%, and 98.8%, respectively. Serous-type tumors were a significantly good prognosis factor for local tumor control after GKRS (p = 0.005). CONCLUSIONS: This study established a relationship between the efficacy of GKRS treatment for brain metastases and the histological type of primary ovarian cancer. GKRS for ovarian cancer brain metastasis can provide satisfactory survival and local control, especially in cases of serous adenocarcinoma.

[A Case of Trigeminal Neuralgia Treated with Microvascular Decompression 10 years after Gamma Knife Radiosurgery].

We report a case of trigeminal neuralgia treated with microvascular decompression 10 years after We report a case of trigeminal neuralgia treated with microvascular decompression 10 years after Gamma Knife radiosurgery was performed. The patient was a 65-year-old female. The root entry zone of the trigeminal nerve received irradiation:a 4-mm shot, with a maximum dose of 80 Gy. The symptoms improved following treatment, however pain recurred five and a half years later. The pain gradually increased over time, to the point where the patient was unable to eat solid food. Carbamazepine was prescribed and the dosage increased. However, side effects such as dizziness and drowsiness manifested. Microvascular decompression was performed, revealing that the trigeminal nerve was markedly atrophied and being pressed upon by the superior cerebellar artery. The superior cerebellar artery was transpositioned with Teflon braided tape to the cerebellar tent. There were no abnormal findings such as arachnoid thickening, adhesions between vessels and nerves, or atherosclerotic plaque in the affected vessels. Pain completely abated following surgery, and side effects such as numbness of the face have not been observed at the time of writing this report.

Impact of temperature decline from the previous day as a trigger of spontaneous subarachnoid hemorrhage: case-crossover study of prefectural stroke database.

OBJECTIVE: Several environmental factors have been reported to correlate with incidence of spontaneous subarachnoid hemorrhage (SAH). However, because of different patient selection and study designs among these studies, meteorological factors that trigger the incidence of SAH in a short hazard period remain unknown. Among meteorological factors, daily temperature changes may disrupt and violate homeostasis and predispose to cerebrovascular circulatory disturbances and strokes. The authors aimed to investigate whether a decline in the temperature from the highest of the previous day to the lowest of the event day (temperature decline from the previous day [TDP]) triggers SAH in the prefecture-wide stroke database. METHODS: All 28 participating institutions with primary or comprehensive stroke centers located throughout Kochi Prefecture, Japan, were included in the study. Data collected between January 2012 and December 2016 were analyzed, and 715 consecutive SAH patients with a defined date of onset were enrolled. Meteorological data in this period were obtained from the Kochi Local Meteorological Observatory. A case-crossover study was performed to investigate association of TDP and other environmental factors with onset of SAH. RESULTS: The increasing TDP in 1°C on the day of the SAH event was associated with an increased incidence of SAH (OR 1.041, 95% CI 1.007-1.077) after adjustment for other environmental factors. According to the stratified analysis, a significant association between TDP and SAH was observed in women, patients < 65 years old, and patients with weekday onset. Among these factors, increasing TDP had a great impact on SAH onset in patients < 65 years old (p = 0.028, Mann-Whitney U-test). CONCLUSIONS: TDP, temperature decline from the highest of the previous day to the lowest of the day, was correlated with the incidence of spontaneous SAH, particularly in younger patients < 65 years old.

Comparison of treatment results between 3- and 2-stage Gamma Knife radiosurgery for large brain metastases: a retrospective multi-institutional study.

OBJECTIVE: In order to obtain better local tumor control for large (i.e., > 3 cm in diameter or > 10 cm3 in volume) brain metastases (BMs), 3-stage and 2-stage Gamma Knife surgery (GKS) procedures, rather than a palliative dose of stereotactic radiosurgery, have been proposed. Here, authors conducted a retrospective multi-institutional study to compare treatment results between 3-stage and 2-stage GKS for large BMs. METHODS: This retrospective multi-institutional study involved 335 patients from 19 Gamma Knife facilities in Japan. Major inclusion criteria were 1) newly diagnosed BMs, 2) largest tumor volume of 10.0-33.5 cm3, 3) cumulative intracranial tumor volume ≤ 50 cm3, 4) no leptomeningeal dissemination, 5) no more than 10 tumors, and 6) Karnofsky Performance Status 70% or better. Prescription doses were restricted to between 9.0 and 11.0 Gy in 3-stage GKS and between 11.8 and 14.2 Gy in 2-stage GKS. The total treatment interval had to be within 6 weeks, with at least 12 days between procedures. There were 114 cases in the 3-stage group and 221 in the 2-stage group. Because of the disproportion in patient numbers and the pre-GKS clinical factors between these two GKS groups, a case-matched study was performed using the propensity score matching method. Ultimately, 212 patients (106 from each group) were selected for the case-matched study. Overall survival, tumor progression, neurological death, and radiation-related adverse events were analyzed. RESULTS: In the case-matched cohort, post-GKS median survival time tended to be longer in the 3-stage group (15.9 months) than in the 2-stage group (11.7 months), but the difference was not statistically significant (p = 0.65). The cumulative incidences of tumor progression (21.6% vs 16.7% at 1 year, p = 0.31), neurological death (5.1% vs 6.0% at 1 year, p = 0.58), or serious radiation-related adverse events (3.0% vs 4.0% at 1 year, p = 0.49) did not differ significantly. CONCLUSIONS: This retrospective multi-institutional study showed no differences between 3-stage and 2-stage GKS in terms of overall survival, tumor progression, neurological death, and radiation-related adverse events. Both 3-stage and 2-stage GKS performed according to the aforementioned protocols are good treatment options in selected patients with large BMs.

Gamma Knife radiosurgery for brain metastases from pulmonary large cell neuroendocrine carcinoma: a Japanese multi-institutional cooperative study (JLGK1401).

OBJECTIVE In 1999, the World Health Organization categorized large cell neuroendocrine carcinoma (LCNEC) of the lung as a variant of large cell carcinoma, and LCNEC now accounts for 3% of all lung cancers. Although LCNEC is categorized among the non-small cell lung cancers, its biological behavior has recently been suggested to be very similar to that of a small cell pulmonary malignancy. The clinical outcome for patients with LCNEC is generally poor, and the optimal treatment for this malignancy has not yet been established. Little information is available regarding management of LCNEC patients with brain metastases (METs). This study aimed to evaluate the efficacy of Gamma Knife radiosurgery (GKRS) for patients with brain METs from LCNEC. METHODS The Japanese Leksell Gamma Knife Society planned this retrospective study in which 21 Gamma Knife centers in Japan participated. Data from 101 patients were reviewed for this study. Most of the patients with LCNEC were men (80%), and the mean age was 67 years (range 39-84 years). Primary lung tumors were reported as well controlled in one-third of the patients. More than half of the patients had extracranial METs. Brain metastasis and lung cancer had been detected simultaneously in 25% of the patients. Before GKRS, brain METs had manifested with neurological symptoms in 37 patients. Additionally, prior to GKRS, resection was performed in 17 patients and radiation therapy in 10. A small cell lung carcinoma-based chemotherapy regimen was chosen for 48 patients. The median lesion number was 3 (range 1-33). The median cumulative tumor volume was 3.5 cm3, and the median radiation dose was 20.0 Gy. For statistical analysis, the standard Kaplan-Meier method was used to determine post-GKRS survival. Competing risk analysis was applied to estimate GKRS cumulative incidences of maintenance of neurological function and death, local recurrence, appearance of new lesions, and complications. RESULTS The overall median survival time (MST) was 9.6 months. MSTs for patients classified according to the modified recursive partitioning analysis (RPA) system were 25.7, 11.0, and 5.9 months for Class 1+2a (20 patients), Class 2b (28), and Class 3 (46), respectively. At 12 months after GKRS, neurological death-free and deterioration-free survival rates were 93% and 87%, respectively. Follow-up imaging studies were available in 78 patients. The tumor control rate was 86% at 12 months after GKRS. CONCLUSIONS The present study suggests that GKRS is an effective treatment for LCNEC patients with brain METs, particularly in terms of maintaining neurological status.

Gamma Knife surgery for patients with jugular foramen schwannomas: a multiinstitutional retrospective study in Japan.

OBJECTIVE This study aimed to explore the efficacy and safety of stereotactic radiosurgery in patients with jugular foramen schwannomas (JFSs). METHODS This study was a multiinstitutional retrospective analysis of 117 patients with JFSs who were treated with Gamma Knife surgery (GKS) at 18 medical centers of the Japan Leksell Gamma Knife Society. The median age of the patients was 53 years. Fifty-six patients underwent GKS as their initial treatment, while 61 patients had previously undergone resection. At the time of GKS, 46 patients (39%) had hoarseness, 45 (38%) had hearing disturbances, and 43 (36%) had swallowing disturbances. Eighty-five tumors (73%) were solid, and 32 (27%) had cystic components. The median tumor volume was 4.9 cm3, and the median prescription dose administered to the tumor margin was 12 Gy. Five patients were treated with fractionated GKS and maximum and marginal doses of 42 and 21 Gy, respectively, using a 3-fraction schedule. RESULTS The median follow-up period was 52 months. The last follow-up images showed partial remission in 62 patients (53%), stable tumors in 42 patients (36%), and tumor progression in 13 patients (11%). The actuarial 3- and 5-year progression-free survival (PFS) rates were 91% and 89%, respectively. The multivariate analysis showed that pre-GKS brainstem edema and dumbbell-shaped tumors significantly affected PFS. During the follow-up period, 20 patients (17%) developed some degree of symptomatic deterioration. This condition was transient in 12 (10%) of these patients and persistent in 8 patients (7%). The cause of the persistent deterioration was tumor progression in 4 patients (3%) and adverse radiation effects in 4 patients (3%), including 2 patients with hearing deterioration, 1 patient with swallowing disturbance, and 1 patient with hearing deterioration and hypoglossal nerve palsy. However, the preexisting hoarseness and swallowing disturbances improved in 66% and 63% of the patients, respectively. CONCLUSIONS GKS resulted in good tumor control in patients with either primary or residual JFSs. Although some patients experienced some degree of symptomatic deterioration after treatment, persistent adverse radiation effects were seen in only 3% of the entire series at the last follow-up. Lower cranial nerve deficits were extremely rare adverse radiation effects, and preexisting hoarseness and swallowing disturbances improved in two-thirds of patients. These results indicated that GKS was a safe and reasonable alternative to surgical resection in selected patients with JFSs.

Stereotactic radiosurgery for intracranial hemangioblastomas: a retrospective international outcome study.

OBJECT: The purpose of this study was to evaluate the role of stereotactic radiosurgery (SRS) in the management of intracranial hemangioblastomas. METHODS: Six participating centers of the North American Gamma Knife Consortium and 13 Japanese Gamma Knife centers identified 186 patients with 517 hemangioblastomas who underwent SRS. Eighty patients had 335 hemangioblastomas associated with von Hippel-Lindau disease (VHL) and 106 patients had 182 sporadic hemangioblastomas. The median target volume was 0.2 cm(3) (median diameter 7 mm) in patients with VHL and 0.7 cm(3) (median diameter 11 mm) in those with sporadic hemangioblastoma. The median margin dose was 18 Gy in VHL patients and 15 Gy in those with sporadic hemangioblastomas. RESULTS: At a median of 5 years (range 0.5-18 years) after treatment, 20 patients had died of intracranial disease progression and 9 patients had died of other causes. The overall survival after SRS was 94% at 3 years, 90% at 5 years, and 74% at 10 years. Factors associated with longer survival included younger age, absence of neurological symptoms, fewer tumors, and higher Karnofsky Performance Status. Thirty-three (41%) of the 80 patients with VHL developed new tumors and 17 (16%) of the106 patients with sporadic hemangioblastoma had recurrences of residual tumor from the original tumor. The 5-year rate of developing a new tumor was 43% for VHL patients, and the 5-year rate of developing a recurrence of residual tumor from the original tumor was 24% for sporadic hemangioblastoma patients. Factors associated with a reduced risk of developing a new tumor or recurrences of residual tumor from the original tumor included younger age, fewer tumors, and sporadic rather than VHL-associated hemangioblastomas. The local tumor control rate for treated tumors was 92% at 3 years, 89% at 5 years, and 79% at 10 years. Factors associated with an improved local tumor control rate included VHL-associated hemangioblastoma, solid tumor, smaller tumor volume, and higher margin dose. Thirteen patients (7%) developed adverse radiation effects (ARE) after SRS, and one of these patients died due to ARE. CONCLUSIONS: When either sporadic or VHL-associated tumors were observed to grow on serial imaging studies, SRS provided tumor control in 79%-92% of tumors.

Stereotactic radiosurgery for patients with multiple brain metastases (JLGK0901): a multi-institutional prospective observational study.

BACKGROUND: We aimed to examine whether stereotactic radiosurgery without whole-brain radiotherapy (WBRT) as the initial treatment for patients with five to ten brain metastases is non-inferior to that for patients with two to four brain metastases in terms of overall survival. METHODS: This prospective observational study enrolled patients with one to ten newly diagnosed brain metastases (largest tumour <10 mL in volume and <3 cm in longest diameter; total cumulative volume ≤15 mL) and a Karnofsky performance status score of 70 or higher from 23 facilities in Japan. Standard stereotactic radiosurgery procedures were used in all patients; tumour volumes smaller than 4 mL were irradiated with 22 Gy at the lesion periphery and those that were 4-10 mL with 20 Gy. The primary endpoint was overall survival, for which the non-inferiority margin for the comparison of outcomes in patients with two to four brain metastases with those of patients with five to ten brain metastases was set as the value of the upper 95% CI for a hazard ratio (HR) of 1·30, and all data were analysed by intention to treat. The study was finalised on Dec 31, 2012, for analysis of the primary endpoint; however, monitoring of stereotactic radiosurgery-induced complications and neurocognitive function assessment will continue for the censored subset until the end of 2014. This study is registered with the University Medical Information Network Clinical Trial Registry, number 000001812. FINDINGS: We enrolled 1194 eligible patients between March 1, 2009, and Feb 15, 2012. Median overall survival after stereotactic radiosurgery was 13·9 months [95% CI 12·0-15·6] in the 455 patients with one tumour, 10·8 months [9·4-12·4] in the 531 patients with two to four tumours, and 10·8 months [9·1-12·7] in the 208 patients with five to ten tumours. Overall survival did not differ between the patients with two to four tumours and those with five to ten (HR 0·97, 95% CI 0·81-1·18 [less than non-inferiority margin], p=0·78; pnon-inferiority<0·0001). Stereotactic radiosurgery-induced adverse events occurred in 101 (8%) patients; nine (2%) patients with one tumour had one or more grade 3-4 event compared with 13 (2%) patients with two to four tumours and six (3%) patients with five to ten tumours. The proportion of patients who had one or more treatment-related adverse event of any grade did not differ significantly between the two groups of patients with multiple tumours (50 [9%] patients with two to four tumours vs 18 [9%] with five to ten; p=0·89). Four patients died, mainly of complications relating to stereotactic radiosurgery (two with one tumour and one each in the other two groups). INTERPRETATION: Our results suggest that stereotactic radiosurgery without WBRT in patients with five to ten brain metastases is non-inferior to that in patients with two to four brain metastases. Considering the minimal invasiveness of stereotactic radiosurgery and the fewer side-effects than with WBRT, stereotactic radiosurgery might be a suitable alternative for patients with up to ten brain metastases. FUNDING: Japan Brain Foundation.

Associations of brachial-ankle pulse wave velocity and carotid atherosclerotic lesions with silent cerebral lesions.

Silent cerebral lesions are increasingly found in mass screenings using MRI and magnetic resonance angiography (MRA). The purpose of this paper is to assess the usefulness of two non-invasive clinical tests-carotid ultrasound examination and brachial-ankle pulse wave velocity (baPWV) measurement-for predicting silent cerebral infarction (SCI) and silent intracranial arterial stenosis. Data were collected on 480 asymptomatic adult subjects who participated in a brain screening program at a single hospital between April 2003 and March 2006. All participants underwent baPWV measurement, B-mode ultrasonography of carotid arteries, MRI, and MRA. Data on 476 (99.1%) subjects were included in the analysis. Among these, 273 (57.4%) were male and the mean age was 51.5 years; 161 (33.8%) had carotid plaque; 33 (6.9%) had increased intima-media thickness (IMT); 99 (20.8%) had SCI; and 7 (1.5%) had intracranial arterial stenosis. The multivariate analysis showed that age (odds ratio [OR]: 1.12; 95% confidence interval [CI]: 1.08-1.17), carotid plaque (OR: 2.69; 1.59-4.56), increased IMT (OR: 2.40; 1.02-5.65), and a history of hypertension treatment (OR 2.22; 1.11-4.43) were significantly associated with SCI. Also, increased IMT (OR 9.70: 1.48-63.71) was related to intracranial arterial stenosis. Brachial-ankle PWV was related to SCI (p<0.01) and intracranial stenosis (p=0.01) in univariate analysis but not in multivariate analysis. The presence of carotid plaque and that of increased IMT on ultrasound examination are useful for assessing the risk of SIC. Increased IMT is also predictive of intracranial arterial stenosis.

Increased intima media thickness and atherosclerotic plaques in the carotid artery as risk factors for silent brain infarcts.

The presence of silent cerebral infarcts (SCIs), defined as lesions > or = 3 mm in diameter on magnetic resonance imaging (MRI), is considered a predictor of symptomatic cerebrovascular disorders (CVDs). Similarly, SCI-like lesions < 3 mm in diameter, lesions which often occur in the deep white matter and basal ganglia, also may be a risk factor for CVD. This study evaluated the relationships between SCI and SCI-like brain lesions, as defined by MRI, and 2 findings on extracranial carotid ultrasonography: intima-media thickness (IMT) and atherosclerotic plaque. We studied data obtained by carotid ultrasonography and cerebral MRI in 448 consecutive subjects without a history of stroke who had undergone comprehensive brain screening (mean age, 51.1 years). The subjects were classified into 4 groups according to the presence of increased (> or = 1 mm) IMT (I) and plaque (P). A total of 110 subjects demonstrated increased IMT (24.6%), and 54 subjects had increased plaque (12.1%). SCI-like lesions were found in 38 subjects (8.5%); single SCI, in 24 (5.4%); and multiple SCIs, in 51 (11.4%). Frequencies of SCI-like lesion(s), single SCI, and multiple SCIs were 6.1%, 12.2%, and 8.7%, respectively, in the I(-)P(-) group; 14.6%, 22.0%, and 13.4% in the I(+)P(-) group; 7.7%, 30.8%, and 26.9% in the I(-)P(+) group; and 17.9%, 39.3%, and 21.4% in the I(+)P(+) group. Multivariate analysis found that the presence of carotid plaques was significantly associated with (1) SCI-like lesion(s) and SCI (odds ratio [OR] = 2.20; 95% confidence interval [CI] = 1.17-4.34), (2) single and multiple SCI (OR = 2.33; 95% CI = 1.16-4.67), and (3) multiple SCIs (OR = 2.31; 95% CI = 1.06-5.03). However, the presence of increased carotid IMT was not significantly associated with any of these 3 categories. Coexistence of increased IMT and plaque was more strongly correlated with SCI than with either lesion alone.

[Usefulness of volume rendering stereo-movie in neurosurgical craniotomies].

In recent years, the advancements in MR technology combined with the development of the multi-channel coil have resulted in substantially shortened inspection times. In addition, rapid improvement in functional performance in the workstation has produced a more simplified imaging-making process. Consequently, graphical images of intra-cranial lesions can be easily created. For example, the use of three-dimensional spoiled gradient echo (3D-SPGR) volume rendering (VR) after injection of a contrast medium is applied clinically as a preoperative reference image. Recently, improvements in 3D-SPGR VR high-resolution have enabled accurate surface images of the brain to be obtained. We used stereo-imaging created by weighted maximum intensity projection (Weighted MIP) to determine the skin incision line. Furthermore, the stereo imaging technique utilizing 3D-SPGR VR was actually used in cases presented here. The techniques we report here seemed to be very useful in the pre-operative simulation of neurosurgical craniotomy.

Diffusion-weighted imaging of traumatic subdural hematoma in the subacute stage.

Five cases of traumatic subdural hematomas in the subacute stage (from 7 to 20 days after head injury) were treated in one male and four females, aged from 63 to 82 years, with evacuation via craniotomy in three and aspiration via burr hole surgery in two. All hematomas were evaluated by T1-, T2-, and diffusion-weighted magnetic resonance imaging, and measurement of the apparent diffusion coefficient (ADC). Diffusion-weighted imaging showed the hematoma as a crescent high intensity area with a low intensity rim close to the brain surface (two-layered structure) in four cases and as high intensity with low intensity components in one case. The high intensity areas under the dura mater on diffusion-weighted imaging appeared as homogeneous high intensity on T1- and T2-weighted imaging in four cases, and inhomogeneous high intensity on T1- and isointensity on T2-weighted imaging in one case. The mean ADC value of the high intensity areas was 0.58 +/- 0.23 (mean +/- standard deviation) x 10(-3) mm2/sec. The operative findings revealed the high intensity areas as solid clots. The low intensity areas on diffusion-weighted imaging appeared as homogeneous high intensity in four cases and inhomogeneous isointensity with high intensity components in one case on T1- and T2-weighted imaging. The mean ADC value of the low intensity areas was 2.03 +/- 0.27 x 10(-3) mm2/sec. The operative findings revealed the low intensity areas as mixtures of resolved clot and cerebrospinal fluid. Diffusion-weighted imaging showed the characteristic two-layered structure in traumatic subdural hematomas in the subacute stage, and analysis of the ADC values was useful for differentiating solid from liquid hematoma and for selection of the surgical procedure.

Subdural hyperintense band on diffusion-weighted imaging of chronic subdural hematoma indicates bleeding from the outer membrane.

The diffusion-weighted magnetic resonance (MR) imaging characteristics of chronic subdural hematoma and the correlation between hematoma liquidity and apparent diffusion coefficient (ADC) were investigated in 26 consecutive patients, 16 males and 10 females aged 42 to 92 years (mean +/- SD 73.3 +/- 13.1 years), with 31 chronic subdural hematomas. The chronic subdural hematomas were divided into homogeneous, separate, and trabecular types based on diffusion-weighted MR imaging findings. Almost all hematomas were low intensity on diffusion-weighted imaging, and the mean ADC value was 1.81 +/- 0.79 x 10(-3) mm2/sec. The high intensity areas in the subdural hematomas consisted of several types: high intensity line along the dura mater (subdural hyperintense band), high intensity along the intrahematoma septum, and laminar shape along the inner membrane. The subdural hyperintense bands accounted for almost all high intensity areas in the subdural hematomas. The mean ADC value of the high intensity areas was 0.76 +/- 0.24 x 10(-3) mm2/sec, close to that of the normal brain. The subdural hyperintense bands were considered to be intracellular and/or extracellular methemoglobin based on the T1- and T2-weighted imaging and intraoperative findings. The subdural hyperintense band is an important finding indicating relatively fresh bleeding from the outer membrane. Diffusion-weighted imaging shows liquid subdural hematoma as low intensity, and measurement of the ADC values can differentiate between liquid and solid components of the chronic subdural hematoma.

Diffusion-weighted magnetic resonance imaging of organized subdural hematoma--case report.

A 59-year-old male presented with a left organized subdural hematoma. The hematoma appeared as a homogeneous low density area on brain computed tomography and as hyperintense and isointense area on both fluid-attenuated inversion recovery and T2-weighted magnetic resonance (MR) imaging. Echo-planar diffusion-weighted MR imaging showed a crescent hyperintense area under the dura mater and an irregular hypointense area over the brain surface in the left subdural space. The apparent diffusion coefficient (ADC) values of the solid and liquid hematoma were 0.86 +/- 0.32 x 10(-3) and 2.56 +/- 0.39 x 10(-3) mm2/sec, respectively. The ADC value of the solid hematoma was similar to acute subdural or intraparenchymal hematoma, and that of the liquid was similar to cerebrospinal fluid. Burr-hole surgery failed to remove all the hematoma, and he complained of persistent headache. The hematoma was removed through a craniotomy without further neurological deficits. Organized subdural hematoma often requires craniotomy for evacuation because of its solid content. Diffusion-weighted MR imaging and measurement of ADC values can differentiate solid from liquid hematoma, so are useful for selection of the surgical procedure.

[A case of organized chronic subdural hematoma presented with transient neurologic deficits].

A 59-year-old diabetic male presented with transient motor aphasia and monoparesis of the right upper limb. Brain CT scan showed a low density area in the left subdural space with a mild midline shift. Magnetic resonance (MR) T2-weighted and fluid-attenuated inversion recovery (FLAIR) imagings revealed homogenous hyperintensity with a hypointense web-like structure in the subdural hematoma. Cervical MR angiography showed no abnormal lesion at the bifurcation of the bilateral common carotid arteries. Conventional cerebral angiography showed an avascular, crescent, space-occupying mass over the left hemisphere without an etiologic lesion of cerebral ischemia. CT perfusion imagings indicated reduced cerebral blood flow (CBF) and prolonged mean transit time (MTT) in the left middle cerebral artery territory underneath the subdural hematoma. No epileptic discharge was found in electroencephalogram. Operative findings indicated that the hematoma was encapsulated with thickened outer and inner membranes including paste-like materials, and the brain surface was intact. Postoperative CT perfusion imagings revealed normal CBF and MTT. The pathophysiological mechanism which the chronic subdural hematoma produces the transient neurological deficit is still uncertain. The mechanical pressure of the hematoma on the neighboring cerebral vessels may cause impairment of blood flow leading to cerebral ischemia and paralysis of function. Our case indicated the transient neurological deficits attributed to a decreased CBF around the subdural hematoma and a change in pressure exerted by the hematoma during changes of head position and increased blood viscosity.

[Gamma knife radiosurgery for spontaneous carotid-cavernous sinus fistula (CCF)].

Gamma knife radiosurgery was carried out for spontaneous CCF (carotid-cavernous sinus fistula) in 8 patients (1 male and 7 females), and its results were reported. The ages ranged from 48 to 74 years with a mean of 60.6 years. As initial treatment before radiosurgery, embolization was carried out except in one patient, and radiotherapy was used in two patients. Six patients were in the category of Barrow's type D, and two patients were in the category of Barrow's type B. As it contained the fistula, the lateral wall of the cavernous sinus was irradiated with 8-14.5 Gy (mean 10.8 Gy). As a result, complete obliteration of CCF was confirmed by DSA in seven of the eight patients between 6 and 18 months after radiosurgery. There were no side effects observed during a follow-up period of 8 to 116 months. Although the main treatment for spontaneous CCF is intravascular surgery at present, gamma knife radiosurgery is a useful adjuvant treatment for the residual CCF after embolization.