Eiji Imamura

Antiplatelet Therapy as a Risk Factor for Microbleeds in Intracerebral Hemorrhage Patients: Analysis Using Specific Antiplatelet Agents

BACKGROUND Although brain microbleed has been reported to be a risk factor for antiplatelet-associated intracerebral hemorrhage, data on the use of specific antiplatelet agents are lacking. In this study, we examined the associations between specific antiplatelets and brain microbleeds in order to help select antiplatelet agents in patients with microbleeds. METHODS We evaluated 1914 consecutive acute stroke patients, including 412 patients with intracerebral hemorrhage and 1502 patients with ischemic stroke. The associations between the presence of microbleeds and antiplatelet use were evaluated, including specific antiplatelet agents (aspirin, clopidogrel, cilostazol, and ticlopidine). RESULTS Antiplatelet use was associated with the presence of microbleeds in patients with intracerebral hemorrhage (odds ratio [OR] 2.418; 95% confidence interval [CI] 1.236-4.730; P = .0099), but not in patients with ischemic stroke. The use of a single antiplatelet medication was not associated with the presence of microbleeds. In patients with intracerebral hemorrhage, aspirin (OR 2.160; 95% CI 1.050-4.443; P = .0364) but not clopidogrel, cilostazol, or ticlopidine was associated with microbleeds. In these patients, dividing brain microbleeds into deep microbleeds and lobar microbleeds revealed an association only between antiplatelet use and the presence of deep microbleeds (OR 2.397; 95% CI 1.258-4.567; P = .0079). None of the antiplatelet agents were associated with the presence of deep microbleeds, although aspirin had a trend of association (OR 1.986; 95% CI 1.000-3.946; P = .0501). CONCLUSIONS Attention to microbleed-positive patients is necessary for the safe use of aspirin in order to avoid antiplatelet-associated hemorrhages, but prospective studies are needed to verify our results.

Early administration of non-vitamin K antagonist oral anticoagulants for acute ischemic stroke patients with atrial fibrillation in comparison with warfarin mostly combined with heparin.

BACKGROUND This study evaluated the rates of new lesions on diffusion-weighted images (DWIs) of magnetic resonance imaging (MRI) and hemorrhagic transformation (HT) during 2 weeks after acute ischemic stroke (AIS) in patients with atrial fibrillation (Af) who were given one of the non-vitamin K antagonist oral anticoagulants (NOACs); this was then compared with those who were given warfarin. METHODS AND RESULTS Consecutive AIS patients with Af were enrolled between January 2008 and June 2013, and those selected were patients who had a MRI that included DWIs both on admission and after 2 weeks, and those given only wafrarin (warfarin group) or only one of the NOACs (NOAC group) within 2 weeks of admission. Of all 257 enrolled patients, 50 patients were selected for the NOAC group (median age of 80.0 years) and 125 patients for the warfarin group (median age of 80.0 years). Both NOAC and warfarin were started at a median of the second day after admission. There was no significant difference in the rates of new lesions on DWIs (26.0% vs. 28.0%, P=0.7888) and HT (30.0% vs. 39.2%, P=0.2536) between the NOAC and warfarin groups. The NOAC group had a lower rate of concomitant use of heparin (44.0% vs. 92.8%, P<0.0001) than the warfarin group. CONCLUSIONS This study suggests that NOACs are suitable for AIS patients with Af, perhaps even better than warfarin, given their simplicity.

Prediction of Pneumonia in Acute Stroke Patients Using Tongue Pressure Measurements

Swallowing dysfunction caused by stroke is a risk factor for aspiration pneumonia. Tongue pressure measurement is a simple and noninvasive method for evaluating swallowing dysfunction. We have hypothesized that low tongue pressure may be able to predict pneumonia occurrence in acute stroke patients. Tongue pressure was measured using balloon-type equipment in 220 acute stroke patients. The modified Mann Assessment of Swallowing Ability (MASA) score was evaluated independently on the same day. Tongue pressure was measured every week thereafter. An improvement in tongue pressure was observed within the first 2 weeks. Receiver operating curve analysis was performed to determine the ability of tongue pressure to predict modified MASA score <95, which suggests swallowing dysfunction. The optimal cutoff for tongue pressure was 21.6 kPa (χ2 = 45.82, p<0.001, sensitivity 95.9%, specificity 91.8%, area under the curve = 0.97). The tongue pressure was significantly lower in patients with pneumonia than in those without pneumonia. Using a Cox proportional hazard model for pneumonia onset with a cutoff tongue pressure value of 21.6 kPa and adjustment for age, sex, and National Institutes of Health Stroke Scale score at admission, the tongue pressure had additional predictive power for pneumonia onset (hazard ratio, 7.95; 95% confidence interval, 2.09 to 52.11; p = 0.0013). In the group with low tongue pressure, 27 of 95 patients showed improvement of tongue pressure within 2 weeks. Pneumonia occurred frequently in patients without improvement of tongue pressure, but not in patients with improvement (31/68 and 2/27, p<0.001). Tongue pressure is a sensitive indicator for predicting pneumonia occurrence in acute stroke patients.

The Association between Hyperintense Vessel Sign and Final Ischemic Lesion Differ in Its Location

BACKGROUND The hyperintense vessel sign (HVS) on fluid-attenuated inversion recovery images can frequently be detected in patients with acute cerebral infarction attributable to large artery stenosis or occlusion. The prognostic values and clinical characteristics of HVS remain to be elucidated. The aim of this study was to evaluate the association of HVS with ischemic lesions and severity of neurologic deficit. METHODS A total of 96 consecutive acute ischemic stroke patients (54 women, median age 76.5 [range 39-97] years), who had symptomatic severe stenosis or occlusion in the proximal middle cerebral artery that was detected with magnetic resonance angiography within 24 hours of onset, were enrolled. The extent of HVS was graded by a systematic quantitative scoring system (the HVS distribution score) based on Alberta Stroke Program Early Computed Tomographic Score. RESULTS An HVS was detected in 89 patients (93%) at admission, and the patients who displayed wider HVS distribution scores exhibited more severe neurologic deficits at admission (P<.05). The follow-up magnetic resonance imaging, which was obtained in 79 patients (82%), was performed an average of 13 days. The association between HVS distribution score and final ischemic lesions was strongly observed (n=67, P<.05) but not in the patients with intravenous thrombolysis (n=12, P=.06). CONCLUSIONS Although the distribution of HVS reflected final ischemic lesion, this association might not apply to the patients with the thrombolysis treatment. The interpretation of HVS distribution score with acute ischemic stroke patients should be discussed dependent on thrombolysis.

Blood Pressure Variability in Acute Ischemic Stroke: Influence of Infarct Location in the Insular Cortex

Background: The aim of this study was to elucidate the influence of insular infarction on blood pressure (BP) variability and outcomes according to the region of the insular cortex affected. Methods: A total of 90 patients diagnosed with acute unilateral ischemic stroke were registered. The BP variability was calculated over 24 h after admission (hyperacute) and for 2–3 days after admission (acute). Patients were classified into groups of right and left, and then right anterior, right posterior, left anterior, and left posterior insular infarction. Results: Patients with insular infarction showed a significantly larger infarct volume, higher modified Rankin scale scores, and lower SD and coefficient of variation (CV) of systolic BP in the hyperacute phase than shown by patients without insular infarction (p < 0.01, p < 0.01, p = 0.02, and p = 0.03, respectively). The SD and CV of systolic BP in the hyperacute phase showed significant differences among the 3 groups with right insular infarction, with left insular infarction, and without insular infarction (p < 0.05 and p < 0.05, respectively). There was a tendency for the systolic BP variability to be lower in patients with right anterior insular infarction than in patients with infarcts in other areas. Conclusion: The right insular cortex, especially the anterior part, might be a hub for autonomic nervous regulation.

Hypoglycemia with focal neurological signs as stroke mimic: Clinical and neuroradiological characteristics

Our aim was to investigate the clinical and radiological features of patients with hypoglycemia with focal neurological signs (HFNS). Among 80 consecutive hypoglycemic patients (blood glucose levels less than 50mg/dL), who had been admitted between October 2008 and May 2012, we selected 11 patients (6 men and 5 women; mean age, 73.2 ± 12 years) with focal neurological signs. The mean initial blood glucose level was 27.9 mg/dL (range, 13-39 mg/dL). The most frequent symptom was unilateral motor weakness (n = 9), which was usually accompanied with mild or moderate alteration of consciousness. All patients had improved initial neurological signs within 1h of glucose injection. The initial DWI demonstrated a hyperintense lesion in the contralateral internal capsule with decreased values on the ADC (apparent diffusion coefficient) map in 2 of the patients (18%). The DWI performed one day later shows only faint lesion. The initial DWI in patients with HFNS may display a hyperintense lesion, which was difficult to distinguish from acute cerebral infarction. Hypoglycemia should be considered in cases with DWI showing a disproportionally small lesion in contrast to neurological signs.

Can Early Effective Anticoagulation Prevent New Lesions on Magnetic Resonance Imaging in Acute Cardioembolic Stroke

BACKGROUND The timing of warfarin administration for acute ischemic stroke (AIS) patients with atrial fibrillation (Af) has not been established. We hypothesized that achieving targeted prothrombin time and international normalized ratio (PT-INR) at 2 weeks could prevent AIS patients with Af from developing a new lesion on diffusion-weighted magnetic resonance imaging (DW-MRI). METHODS Of consecutively enrolled AIS patients with Af between 2008 and 2011, we selected the patients who were given warfarin within 2 weeks of admission and had DW-MRI and blood test for PT-INR both on admission and at 2 weeks. Warfarin was started as early as possible and heparin was administered until the targeted PT-INR (2.0-3.0 for patients aged <70 years or 1.6-2.6 for those aged ≥70 years) was achieved. RESULTS One hundred and twenty-three patients were selected, consisting of 88 patients without a new lesion and 35 patients with a new lesion. Patients with a new lesion had a significantly higher median score on National Institutes of Health Stroke Scale (11.0 vs. 5.5, P = .0053), a lower rate of achieving targeted PT-INR at 2 weeks (25.7% vs. 48.9%, P = .0190), and a lower median dosage of warfarin at 2 weeks (2.0 mg vs. 2.5 mg, P = .0209) than patients without a new lesion. Multivariate logistic regression analysis showed that failure to achieve targeted PT-INR (P = .0298) was significantly associated with the occurrence of a new lesion. CONCLUSIONS Our findings suggest that achieving targeted PT-INR at 2 weeks by using warfarin prevents new lesions in AIS patients with Af.

Subarachnoid hemorrhage after transient global amnesia caused by cerebral venous congestion: case report

BackgroundTransient global amnesia is reported to be caused by cerebral venous congestion. Internal jugular venous flow reversal in particular with the Valsalva maneuver leads to cerebral venous congestion. In addition, Valsalva maneuver can also induce subarachnoid hemorrhage. Transient global amnesia and subarachnoid hemorrhage might have common a pathophysiology in cerebral venous congestion.Case presentationWe report here the case of a 57-year-old woman who twice experienced convexal subarachnoid hemorrhage just after straining at stool following an episode of transient global amnesia. Digital subtraction angiography showed left temporal congestion. Left jugular vein ultrasonography revealed reflux with the Valsalva maneuver only in acute phase, indicating transient cerebral venous congestion.ConclusionsSubarachnoid hemorrhage followed by transient global amnesia indicates a common factor between them. Transient venous congestion is discussed in order to explain this rare phenomenon.