Aneurysmal subarachnoid hemorrhage occurring during sleep: Clinical characteristics and risk factors.

BACKGROUND: Aneurysmal subarachnoid hemorrhage (aSAH) is known to be triggered by several specific human activities. Sleep, by contrast, has not been considered a triggering activity for aSAH, and clinical characteristics of patients who sustain aSAH during sleep have rarely been reported in the literature. METHODS: This is a retrospective analysis on the data acquired through a multicenter aSAH registry. Between January 2019 and December 2021, a total of 732 aSAH patients had been registered into our database. After excluding 109 patients whose activities at aSAH onset had been unidentifiable, the remaining 623 aSAH patients were dichotomized to 59 patients who sustained aSAH during sleep (Sleep group) and 564 patients who sustained aSAH during daytime activities (Awake group). Two-group comparison of demographic variables and multivariate logistic regression analysis were performed to clarify their clinical characteristics and identify potential risk factors. RESULTS: The Sleep group exhibited significantly higher frequencies of diabetes (15.5 % vs. 6.4 %, p = 0.01) and antiplatelet use (13.8 % vs. 4.6 %, p=0.004) than the Awake group. Furthermore, multivariate logistic regression analysis showed that diabetes (OR, 3.051; 95 % CI, 1.281-7.268; p = 0.012) and antiplatelet use (OR, 3.640; 95 % CI, 1.422-9.316; p = 0.007) were correlated with aSAH occurring during sleep. There were no significant inter-group differences in the patient outcomes evaluated at discharge. CONCLUSION: The current results indicate that risk factors may exist for aSAH occurring during sleep. Further investigations on how comorbidities such as diabetes, antiplatelet use and sleep apnea affect human hemodynamic and hemostatic parameters during sleep is warranted to better understand those relationships.

The impact of SAH finding on CT to the clinical outcome after mechanical thrombectomy for large vessel occlusion.

BACKGROUND AND PURPOSE: Whether subarachnoid haemorrhage (SAH) after mechanical thrombectomy affects the clinical outcomes of patients with acute large-vessel occlusion remains unclear. This study aimed to investigate the clinical impact of SAH on computed tomography (CT) after mechanical thrombectomy. METHODS: The SKIP study was an investigator-initiated, multicentre, randomised, open-label clinical trial. This study was performed in 23 hospital networks in Japan from January 1, 2017, to July 31, 2019. Among the 204 patients, seven were excluded because they did not undergo mechanical thrombectomy (MT) and had a modified Rankin scale (mRS) score > 2. The main outcome was the association between SAH within 36 h after mechanical thrombectomy and the clinical outcome at 90 days. RESULTS: Among 197 patients, the median age was 74 (67-79) years, 62.9% were male. Moreover, 26 (13.2%) patients had SAH (seven isolated SAH) on CT within 36 h. The SAH rate did not differ according to IV rt-PA administration (p = 0.4). The rate of favourable clinical outcomes tended to be lower in patients with SAH rather than patients without SAH (11 [42%] vs. 106 [62%], p = 0.08). Among the seven patients with isolated SAH, 6 showed favourable outcomes at 90 days. In the multivariate regression analysis, the presence of SAH within 36 h from onset was not associated with clinical outcome (Odd ratio, 0.59; 95% confidence interval, 0.18-1.95; p = 0.38). CONCLUSIONS: Among patients with acute stroke treated with MT, SAH, especially isolated SAH findings on CT, were not associated with poor clinical outcomes after 90 days. TRIAL REGISTRATION NUMBER: UMIN000021488.

Ultra-early rt-PA administration should improve patient outcome on mechanical thrombectomy: Post hoc analysis of SKIP.

BACKGROUND: To investigate whether ultra-early recombinant tissue-plasminogen activator (rt-PA) administration can improve patient outcomes on mechanical thrombectomy (MT) in patients with large vessel occlusion (LVO). METHODS: Participants comprised rt-PA-eligible 204 patients with internal carotid artery or middle cerebral artery occlusion in the SKIP trial, who were randomly assigned to receive mechanical thrombectomy alone or combined intravenous thrombolysis (rt-PA: alteplase at 0.6 mg/kg) plus mechanical thrombectomy. We assessed associations between onset-to-puncture time and onset-to-rt-PA administration time and frequency of favorable outcome at 90 days and any intracerebral hemorrhage (ICH) at 36 h after onset. RESULTS: As a cut-off onset-to-puncture time for favorable outcome, receiver operating characteristic curves defined 2.5 h (57% sensitivity, 62% specificity). For onset-to-puncture times ≤2.5 h and > 2.5 h, frequencies of favorable outcomes were 72% and 63% (p = 0.402) in patients with rt-PA therapy and 44% and 58% (p = 0.212) in patients without rt-PA therapy, respectively. In terms of onset-to-rt-PA administration time, frequencies of favorable outcomes among patients with ultra-early rt-PA administration at ≤100, >100 min after onset, and without rt-PA therapy with onset-to-puncture time ≤ 2.5 h, and with and without rt-PA therapy with onset-to-puncture time > 2.5 h were 84% and 64%, 63%, and 44% and 58%, respectively (p = 0.025). Frequencies of any ICH among those patients were 37% and 32%, 32%, and 63% and 40%, respectively (p = 0.006). CONCLUSION: Ultra-early rt-PA administration should improve patient outcomes on mechanical thrombectomy among patients with LVO. Relatively late rt-PA administration might increase the frequency of any ICH.

Intravenous Alteplase is Associated with First Pass Effect in Stent-retriever but not ADAPT Thrombectomy : Post Hoc Analysis of the SKIP Study.

PURPOSE: To investigate the effect of alteplase, either combined with stent-retriever thrombectomy or a direct aspiration first pass technique (ADAPT), in patients with large-vessel occlusion stroke. METHODS: This was a retrospective post hoc analysis of data from The Direct Mechanical Thrombectomy in Acute LVO Stroke (SKIP) study. Patients were divided into two groups according to the first-line thrombectomy technique: stent-retriever and ADAPT. Each group was further divided into two subgroups, namely MT and MT + alteplase. The procedural outcomes, such as first pass effect (FPE) ratio and number of passes, were evaluated. The clinical outcomes included mRS score at 3 months. RESULTS: A total of 180 patients were included (116 in the stent-retriever group and 64 in the ADAPT group). No interaction was detected between the first-line technique and alteplase administration. In the stent-retriever group, after adjusting for factors associated with FPE, the adjusted odds ratio (95% confidence interval) of FPE of the MT + alteplase subgroup versus the MT subgroup was 3.57 (1.5-8.48) and in the ADAPT group it was 1.35 (0.37-4.91). With alteplase, the number of passes decreased with adjusted odds ratios of 0.59 (0.37-0.93) in the stent-retriever group but not in the ADAPT group. In both first-line technique groups, clinical outcomes did not differ between subgroups. CONCLUSION: In the SKIP study, alteplase administration was associated with increased FPE when combined with stent-retriever thrombectomy, but not with ADAPT. We found no differences in the clinical outcomes.

Effect of Mechanical Thrombectomy Without vs With Intravenous Thrombolysis on Functional Outcome Among Patients With Acute Ischemic Stroke: The SKIP Randomized Clinical Trial.

IMPORTANCE: Whether intravenous thrombolysis is needed in combination with mechanical thrombectomy in patients with acute large vessel occlusion stroke is unclear. OBJECTIVE: To examine whether mechanical thrombectomy alone is noninferior to combined intravenous thrombolysis plus mechanical thrombectomy for favorable poststroke outcome. DESIGN, SETTING, AND PARTICIPANTS: Investigator-initiated, multicenter, randomized, open-label, noninferiority clinical trial in 204 patients with acute ischemic stroke due to large vessel occlusion enrolled at 23 hospital networks in Japan from January 1, 2017, to July 31, 2019, with final follow-up on October 31, 2019. INTERVENTIONS: Patients were randomly assigned to mechanical thrombectomy alone (n = 101) or combined intravenous thrombolysis (alteplase at a 0.6-mg/kg dose) plus mechanical thrombectomy (n = 103). MAIN OUTCOMES AND MEASURES: The primary efficacy end point was a favorable outcome defined as a modified Rankin Scale score (range, 0 [no symptoms] to 6 [death]) of 0 to 2 at 90 days, with a noninferiority margin odds ratio of 0.74, assessed using a 1-sided significance threshold of .025 (97.5% CI). There were 7 prespecified secondary efficacy end points, including mortality by day 90. There were 4 prespecified safety end points, including any intracerebral hemorrhage and symptomatic intracerebral hemorrhage within 36 hours. RESULTS: Among 204 patients (median age, 74 years; 62.7% men; median National Institutes of Health Stroke Scale score, 18), all patients completed the trial. Favorable outcome occurred in 60 patients (59.4%) in the mechanical thrombectomy alone group and 59 patients (57.3%) in the combined intravenous thrombolysis plus mechanical thrombectomy group, with no significant between-group difference (difference, 2.1% [1-sided 97.5% CI, -11.4% to ∞]; odds ratio, 1.09 [1-sided 97.5% CI, 0.63 to ∞]; P = .18 for noninferiority). Among the 7 secondary efficacy end points and 4 safety end points, 10 were not significantly different, including mortality at 90 days (8 [7.9%] vs 9 [8.7%]; difference, -0.8% [95% CI, -9.5% to 7.8%]; odds ratio, 0.90 [95% CI, 0.33 to 2.43]; P > .99). Any intracerebral hemorrhage was observed less frequently in the mechanical thrombectomy alone group than in the combined group (34 [33.7%] vs 52 [50.5%]; difference, -16.8% [95% CI, -32.1% to -1.6%]; odds ratio, 0.50 [95% CI, 0.28 to 0.88]; P = .02). Symptomatic intracerebral hemorrhage was not significantly different between groups (6 [5.9%] vs 8 [7.7%]; difference, -1.8% [95% CI, -9.7% to 6.1%]; odds ratio, 0.75 [95% CI, 0.25 to 2.24]; P = .78). CONCLUSIONS AND RELEVANCE: Among patients with acute large vessel occlusion stroke, mechanical thrombectomy alone, compared with combined intravenous thrombolysis plus mechanical thrombectomy, failed to demonstrate noninferiority regarding favorable functional outcome. However, the wide confidence intervals around the effect estimate also did not allow a conclusion of inferiority. TRIAL REGISTRATION: umin.ac.jp/ctr Identifier: UMIN000021488.

Optimal Heating Temperature and Time for Echelon 10 and Excelsior SL-10 Shaping Using a Heat Gun.

Objective: The optimal heating temperature and time for the Echelon10 and Excelsior SL-10 microcatheters using a heat gun was investigated. The durability of the microcatheters after heat gun shaping for the second and third times was also examined. Methods: HAKKO FV-310 was used as the heat gun in this study. This heat gun can be set to 115°C, 125°C, and others. We measured the temperature at 2.5 cm from the nozzle of the heat gun. The Echelon10 and SL-10 microcatheters were shaped under two temperature conditions (115°C and 125°C) and three heating times (30 sec, 60 sec, and 90 sec). The microcatheter shape before heating had twice the curvature of the targeted shape. Results: The temperatures at 2.5 cm from the nozzle were 120.6°C and 127.8°C with the heat gun set at 115°C and 125°C, respectively. There was no macroscopic difference in the results of heat gun shaping of the Echelon10 among temperature settings (115°C and 125°C) or heating times (30 sec, 60 sec, and 90 sec). As degeneration of the heated tip of the SL-10 at 125°C occurred in four of five trials, heat gun shaping was performed using the 115°C setting. There was no macroscopic difference in the results of heat gun shaping of the SL-10 among heating times. Shaping for the second and third times was successful at 115°C and 30-sec heating time. Conclusions: The Echelon10 and SL-10 can be successfully shaped from twice the curvature of the targeted shape using a heat gun at 120°C for 30 sec. Shaping for the second and third times was successful using the same settings. Degeneration of the SL-10 was noted at temperatures above 130°C.

Stent Migration during Coil Embolization with an Open Cell Stent: A Report of Three Cases.

Objective: Among 36 cerebral aneurysm cases of stent-assisted coil embolization with the Neuroform Atlas since April 2017, there were three cases of stent migration during the operation. The status of stent deployment, cause of trouble, results of coil embolization, and complications were assessed. Case Presentations: There were two cases with trouble during stent deployment, a case of internal carotid artery aneurysm, and a case of middle cerebral artery (MCA) aneurysm. The proximal marker of the stent was advanced during stent deployment with the simple pull maneuver, then a part of the stent migrated to the aneurysm sac in both cases. Stent migration to the aneurysm sac during microcatheter navigation by the trans-cell technique occurred in another MCA aneurysm case. No postoperative complications were observed, and a volume embolization ratio (VER) of 24.1%-33% was achieved in these three cases. Conclusions: The Neuroform Atlas is a safe and convenient stent system. However, stent advancement during deployment and migration during trans-cell microcatheter navigation can occur.

The randomized study of endovascular therapy with versus without intravenous tissue plasminogen activator in acute stroke with ICA and M1 occlusion (SKIP study).

RATIONALE: Bridging therapy with endovascular therapy (EVT) and intravenous thrombolysis (IVT) has been reported to improve outcomes for acute stroke patients with large-vessel occlusion in the anterior circulation. While the IVT may increase the reperfusion rate, the risk of hemorrhagic complications increases. Whether EVT without IVT (direct EVT) is equally effective as bridging therapy in acute stroke remains unclear. AIM: This randomized study of endovascular therapy with versus without intravenous tissue plasminogen activator for acute stroke with ICA and M1 occlusion aims to clarify the efficacy and safety of direct EVT compared with bridging therapy. METHODS AND DESIGN: This is an investigator-initiated, multicenter, prospective, randomized, open-treatment, blinded-endpoint clinical trial. The target patient number is 200, comprising 100 patients receiving direct EVT and 100 receiving bridging therapy. STUDY OUTCOME: The primary efficacy endpoint is a modified Rankin Scale score of 0-2 at 90 days. Safety outcome measures are any intracranial hemorrhage at 24 h. DISCUSSION: This trial may help determine whether direct EVT should be recommended as a routine clinical strategy for ischemic stroke patients within 4.5 h from onset. Direct EVT would then become the choice of therapy in stroke centers with endovascular facilities. TRIAL REGISTRATION: UMIN000021488.

Cerebral Microbleeds Detected Using 3.0T Magnetic Resonance Imaging in 2,003 Patients with Ischemic or Hemorrhagic Stroke.

INTRODUCTION: Compared with 1.5T magnetic resonance imaging (MRI), using 3.0T MRI makes it easier to detect cerebral microbleeds (CMBs). We used 3.0T MRI to investigate the backgrounds, risk factors, and number and location of CMBs in patients with ischemic or hemorrhagic stroke. METHODS: We extracted data on clinical characteristics, risk factors, and number and location of CMBs in 2,003 patients treated between January 2010 and December 2014 within one week of stroke occurrence. We then carried out multivariate analysis of the data. RESULTS: CMBs were present in 1,025 patients. The numbers of CMBs in ischemic stroke and hemorrhagic stroke patients were 9,410 and 6,419, respectively. Patients with CMBs showed significantly higher rates of cognitive impairment (p < 0.001, odds ratio [OR] = 1.514), hypertension (p < 0.001, OR = 3.145), previous history of stroke (p < 0.001, OR = 1.782), and presence of hemorrhagic stroke (p < 0.001, OR = 2.066). The use of antithrombotic medication before the stroke did not affect the incidence of CMBs. In ischemic stroke patients, patients with small vessel occlusion had a significantly greater rate of previous history of hemorrhagic stroke (p = 0.046) and number of patients with CMBs (p < 0.001) than those with cardioembolism. CONCLUSIONS: CMBs were well observed in patients with small vessel disease, and hypertension was an important factor in ischemic and hemorrhagic stroke. Antithrombotic medication is not associated with the development of CMBs if adequate antihypertensive therapy is provided.

De Novo Arteriovenous Malformation after Aneurysm Clipping.

We report a 73-year-old woman with de novo arteriovenous malformations (AVMs) that developed in the ipsilateral parietal lobe after craniotomy and aneurysm clipping. While intracerebral AVMs are considered to be congenital lesions, there have been several reported cases of acquired AVM arising after ischemic or traumatic episodes. We summarize previously reported cases of such acquired 'de novo' AVMs with a discussion of some pathophysiological responses or factors suggested to promote their development.

Identification of hemodynamically compromised regions by means of cerebral blood volume mapping utilizing computed tomography perfusion imaging.

The aim of the study was to evaluate the potential role of computed tomography perfusion (CTP) imaging in identifying hemodynamically compromised regions in patients with occlusive cerebrovascular disease. Twelve patients diagnosed with either occlusion or severe stenosis of the internal carotid artery or the M1 portion of the middle cerebral artery underwent CTP imaging. The data was analyzed by an automated ROI-determining software. Patients were classified into two subgroups: an asymptomatic group consisting of three patients in whom perfusion pressure distal to the site of occlusion/stenosis (PPdis) could be maintained in spite of the arterial occlusion/stenosis, and a symptomatic group consisting of nine patients in whom PPdis could not be maintained enough to avoid watershed infarction. Four CTP-related parameters were independently compared between the two groups. Significant differences were determined using a two-sample t-test. When statistically significant differences were identified, cut-off points were calculated using ROC curves. Analysis revealed statistically significant differences between the asymptomatic and symptomatic subgroups only in the measure of relCBV (p=0.028). Higher relCBV values were observed in the symptomatic subgroup. ROC curve analysis revealed 1.059 to be the optimal relCBV cut-off value for distinguishing between the asymptomatic and symptomatic subgroups. The data revealed that, in patients whose PPdis is maintained, relCBV remains around 1.00. Conversely, in patients whose PPdis decreased, relCBV increased. From these findings, we conclude that elevation of relCBV as observed using CTP imaging accurately reflects the extent of compensatory vasodilatation involvement and can identify hemodynamically compromised regions.

Characteristics of subcortical infarction due to distal MCA penetrating artery occlusion.

OBJECTIVE: Isolated deep subcortical infarcts develop as a result of occlusion of the penetrating arteries from the internal carotid artery (ICA) and the proximal (M1) and distal middle cerebral artery (MCA). However, the clinical and neuroimaging characteristics of infarcts due to the occlusion of the distal MCA penetrating artery are unclear. METHODS: Consecutive patients with ischemic stroke or transient ischemic attack with magnetic resonance imaging (MRI) performed within 2days of onset were studied retrospectively. Using coronal MRI data, isolated deep subcortical infarcts were classified into two groups: 1) proximal group, described as being longer than they are wide, which were expected to be related to the occlusion of the ICA or M1 penetrating artery; and 2) distal group, described as oblong, which were expected to be associated with the occlusion of penetrating arteries from the distal MCA (M2/M3/M4). RESULTS: A total of 653 consecutive acute ischemic stroke patients (proximal group, 50 [7.7%]; distal group, 14 [2.1%]) were enrolled. Baseline clinical characteristics were not different between the 2 groups. Modified Rankin Scale scores were lower in the distal group than in the proximal group 3months after stroke onset (1.43±0.36 vs. 2.26±1.35, p=0.023). We measured the lengths of the infarcts in the X and Y directions using axial MRI. The X/Y ratio was larger in the distal group than in the proximal group (1.3±0.6 vs. 0.7±0.2, p<0.01), which indicated that distal MCA penetrating artery infarcts appear more oblong on axial MRI. CONCLUSIONS: One cause for deep subcortical infarction is the occlusion of the distal MCA penetrating arteries, which occurs in 22% of patients with deep subcortical infarctions. These patients had better clinical outcomes than those with ICA and M1 penetrating artery infarctions. Distal MCA penetrating artery infarctions appear oblong on axial MRI.

Correlation between the Occlusion Site and Clinical Outcome after Acute Ischemic Stroke.

OBJECTIVE: The significance of early mild clinical improvement after intravenous tissue plasminogen activator (IVtPA) treatment is unclear. Therefore, we examined whether the timing of clinical improvement after IVtPA predicted the clinical outcome at 3 months. METHODS: Consecutive patients with acute cerebral infarction in the anterior circulation who received IVtPA treatment within 3 hours of the onset of symptoms were enrolled in the study. Patients were classified according to the timing of clinical improvement [early responder (ER), National Institutes of Health Stroke Scale (NIHSS) score improved ≥4 points or who had a score of 0 within 2 hours after IVtPA; late responder (LR), a similar improvement between 2 and 24 hours; and non-responder (NR)] and according to the arterial occlusion site (P group, internal carotid artery and proximal middle cerebral artery M1 region; and D group, distal M1 and M2). RESULTS: Ninety-three patients [median age, 74 (67-79) years; 54 men (58%); median NIHSS score, 11 (7-16)] were enrolled in the study. The P group consisted of 48 (52%) patients and the D group consisted of 45 (48%) patients. Thirty-eight patients (41%) were classified as ERs, 20 (22%) as LRs, and 35 (38%) as NRs. On a multivariate regression analysis, the P group [odds ratio (OR), 3.24; 95% confidence interval (CI), 1.08-10.45; p=0.036] and NR (OR, 4.04; 95% CI, 1.29-14.27; p=0.016) were independent predictors of a poor outcome. ER (47%, p=0.01) and LR (45%, p=0.01) patients showed fewer poor outcomes than NR (77%) patients, but the rate did not differ significantly between the ER and LR patients. CONCLUSION: Early mild clinical recovery did not predict a good outcome. The occlusion site was a stronger predictor of clinical improvement after IVtPA administration.

Hemodynamic stress distribution reflects ischemic clinical symptoms of patients with moyamoya disease.

OBJECTIVE: Currently, the probability of diagnosing asymptomatic moyamoya disease is increasing. In this study, we consider a less invasive method for predicting future ischemic symptoms in patients with moyamoya disease. METHODS: We reviewed cerebral blood flow (CBF)-related data obtained by xenon CT imaging (XeCT) in six patients with ischemic-type or asymptomatic moyamoya disease. The data were obtained as volume data using a 320-row CT, and applied to the automated region-of-interest-determining software (3DSRT) and converted to standardized images. Eight CBF-related parameters, including CBF value, cerebrovascular reserve capacity (CVRC), and hemodynamic distribution (hdSD), were compared between asymptomatic hemispheres and ischemic symptomatic hemispheres. A significant difference was determined by a two-sample t test. A difference with p<0.05 was considered significant. When statistically significant differences between parameters of asymptomatic hemispheres and ischemic symptomatic hemispheres were identified, cut-off points were calculated with receiver operating characteristic (ROC) curves. Change in the parameters before and after bypass surgery was also assessed. RESULTS: Of the eight CBF-related parameters evaluated, statistically significant differences between the asymptomatic hemispheres and ischemic hemispheres were observed in the CBF value of the MCA region (CBF-MCA), both at rest and after acetazolamide loading, and in the hdSD, also both at rest and after acetazolamide loading. Of the four statistically significant parameters, ROC analysis revealed that the hdSD at rest and CBF-MCA after acetazolamide loading were the most sensitive and specific parameters (threshold 1.2, sensitivity 1, specificity 1 for hdSD at rest, and threshold 26.44mL/100g/min, sensitivity 1, specificity 1 for CBF-MCA after acetazolamide loading). From the CBF data obtained both before and after surgery from the three patients who had undergone direct bypass surgeries, the hdSD was higher than the threshold of 1.2 before surgery but decreased to lower than the threshold of 1.2 after surgery. Ischemic symptoms also resolved after surgery. CONCLUSIONS: The data showed that hdSD at rest and CBF-MCA after acetazolamide loading reflects ischemic symptoms of patients with moyamoya disease. Thus, these parameters could be used as ischemic symptom markers for following patients with moyamoya disease. hdSD at rest is important because it is less invasive and can be performed without acetazolamide loading.

Prediction of cerebrovascular reserve capacity by computed tomography perfusion using 320-row computed tomography.

BACKGROUND: Acetazolamide loading has been the "gold standard" for evaluating cerebrovascular reserve capacity (CVRC). However, life-threatening side effects of acetazolamide have recently been reported. The aim of the study was to identify alternative methods for evaluating CVRC. METHODS: We reviewed 6 patients who underwent both computed tomography perfusion (CTP) imaging and xenon CT (XeCT) imaging with and without acetazolamide loading during the same periods. The data were obtained as volume data using 320-row CT and applied to the automated region of interest-determining software and converted to standardized images. Correlations between CVRC and CTP parameters were analyzed by Pearson correlation coefficient analysis, and simple regression was used to assess the relationship between the data. When statistically significant, correlation between CVRC and any CTP data is identified, and cutoff points for CVRC 30% and 10% were calculated with receiver operating characteristic curves. RESULTS: Of 4 CTP parameters evaluated, statistically significant correlations were observed between time to peak (TTP) by CTP and CVRC (P < .0001, r = -.7228) calculated from XeCT. The regression line using CVRC as outcome variable (y) and using TTP as predictor variable (x) was y = -9.062x + 140.1. The cutoff value for the TTP for CVRC less than 10% was 12.56 seconds (sensitivity of 86% and specificity of 85%) and that for CVRC less than 30% was 9.34 seconds (sensitivity of 77% and specificity of 96%). CONCLUSIONS: TTP calculated from CTP data correlated well with the CVRC calculated from XeCT data. These results suggest that TTP calculated from CTP could be used to estimate CVRC in patients with occlusive cardiovascular disease.

Comparison of cerebral blood flow data obtained by computed tomography (CT) perfusion with that obtained by xenon CT using 320-row CT.

Cerebral blood flow (CBF) data obtained by computed tomography perfusion (CTP) imaging have been shown to be qualitative data rather than quantitative, in contrast with data obtained by other imaging methods, such as xenon CT (XeCT) imaging. Thus, interpatient comparisons of CBF values themselves obtained by CTP may be inaccurate. In this study, we have compared CBF ratios as well as CBF values obtained from CTP-CBF data to those obtained from XeCT-CBF data for the same patients to determine CTP-CBF parameters that can be used for interpatient comparisons. The data used in the present study were obtained as volume data using 320-row CT. The volume data were applied to an automated region of interest-determining software (3DSRT, version 3.5.2 ) and converted to 59 slices of 2 mm interval standardized images. In the present study, we reviewed 10 patients with occlusive cerebrovascular diseases (CVDs) undergoing both CTP and XeCT in the same period. Our study shows that ratios of CBF measurements, such as hemodynamic stress distribution (perforator-to-cortical flow ratio of middle cerebral artery [MCA] region) or the left/right ratio for the region of the MCA, calculated using CTP data have been shown to correlate well with the same ratios calculated using XeCT data. These results suggest that such CBF ratios could be useful for generating interpatient comparisons of CTP-CBF data obtained by 320-row CT among patients with occlusive CVD.

Usefulness of Preoperative Surgical Simulation with Three-Dimensional Fusion Images for Resection of Cerebral Cavernous Malformations Near Broca's Area.

Treating subcortical brain lesions in or near eloquent areas is challenging not only because lesions must be resected while preserving brain tissue involved in essential functions, but also because lesions often cannot be easily identified from the surface of the brain. Here, we report 2 cases of cerebral cavernous malformations near Broca's area. In both cases, lesions were surgically removed by utilizing three-dimensional fusion images created using preoperative magnetic resonance imaging and computed tomography data. Excisions were completed without any worsening of speech function, and the use of presurgical simulations was found to be useful in the design and execution of the actual operations. The technique described in this report serves as a useful tool in simulating surgical strategies by using brain gyri and sulci as surgical landmarks. Furthermore, in contrast to other intraoperative techniques, this method can aid in shortening the duration of surgery and can help limit damage to eloquent areas of the brain.

Neurenteric cysts found on the outer membrane of a subdural haematoma.

We report on a patient initially diagnosed with a chronic subdural haematoma that was resistant to treatment. After the second burr hole craniostomy within a half month failed to resolve the subdural haematoma (SDH), we performed a craniotomy to identify the point of bleeding. Macroscopic evaluation showed that most of the outer membrane of the SDH was transparent; however, further examination revealed the presence of multiple white regions. Pathologic examination showed that the white regions were fluid filled and surrounded by columnar ciliated epithelial cells. These lesions were pathologically diagnosed as neurenteric cysts. To our knowledge, this is the first report on a patient with neurenteric cysts found on the outer membrane of a CSDH. We agree that a craniotomy is a treatment of last resort for recurrent CSDHs; however, sometimes this procedure can be very useful for identifying underlying causes of obstinate SDHs as well as for their treatment.

Severe parkinsonism following endoscopic third ventriculostomy for non-communicating hydrocephalus--case report.

A 23-year-old male with non-communicating hydrocephalus caused by intraventricular hemorrhage from an arteriovenous malformation was treated by endoscopic third ventriculostomy (ETV) after repeated ventricular cerebrospinal fluid drainage and removal of ventriculoperitoneal shunt due to infection. Postoperatively, the patient developed robust rigidity and akinesia with mutism, suggesting secondary parkinsonism. These symptoms showed marked improvement after administration of levodopa, and were not aggravated after discontinuation. The pathophysiology of this case might involve dysfunction of the dopaminergic system caused by repeated compression and release of the paraventricular white matter. Careful perioperative management not leading to excessive dilation of the the ventricles should be considered for ETV for non-communicating hydrocephalus to avoid this unexpected complication.