Satoko Mizuno

Transient neurological attack before vertebrobasilar stroke

BACKGROUND Patients with vertebrobasilar (VB) circulation ischemia can present with nonspecific symptoms, which complicate the distinction of transient ischemic attack (TIA) from other benign disorders. According to previously accepted classifications, typical TIA does not occur with VB symptom such as vertigo, diplopia, or dysarthria in isolation. However, there is a lack of evidence to support this hypothesis. METHODS This hospital-based study included 214 consecutive patients with acute ischemic VB stroke. We defined transient neurological attacks (TNAs) as temporary (<24h) episodes with neurological symptoms, and further divided them into TIA, nonspecific TNA, or other specific disorder groups. We investigated the incidence and clinical symptoms of TNAs within 3months prior to the stroke episode, and comparisons were made between patients with and without previous TNA history with respect to their background and stroke profiles. RESULTS Among 214 patients with VB stroke, 56 (26.2%) had previous TNAs. Six of them were diagnosed with other specific disorders and excluded from the analysis. The remaining 33 and 17 were diagnosed with TIA and nonspecific TNA, respectively. Twenty-one (42.0%) had attacks with a nonfocal symptom in isolation, and acute infarction in neuroimaging was confirmed in 4 of these patients. Vertigo was the most frequent nonspecific TNA symptom. Patients with prior TNA had a significantly higher rate of atherothrombotic stroke than those without TNA (40.0% vs. 21.5%, P=0.009). CONCLUSIONS A considerable fraction of TIAs due to VB circulation ischemia may be overlooked among clinically nonfocal TNAs.

Prolonged QTc Interval Predicts Poststroke Paroxysmal Atrial Fibrillation

Background and Purpose— Paroxysmal atrial fibrillation (PAF) is often difficult to detect in patients with acute ischemic stroke. We aimed to assess the predictive value of a prolonged QT interval corrected for heart rate (QTc) in PAF detection after acute ischemic stroke. Methods— We enrolled 972 patients with acute ischemic stroke consecutively extracted from our observational stroke registry system. Exclusion criteria were as follows: (1) AF on the initial 12-lead ECG (n=171); (2) previously diagnosed PAF (n=47); and (3) the use of a cardiac pacemaker (n=10). Of the 972 patients, 744 (mean age, 67.6 years; men, 62.6%) were eligible for analysis. The clinical characteristics and 12-lead ECG findings of the patients with and without PAF were compared, and multiple logistic regression analysis was performed to identify predictors of poststroke PAF. Results— The poststroke cardiac work-up yielded 69 (9.3%) de novo PAF cases among the 744 patients. The QTc interval was significantly longer in patients with PAF than in those without PAF (436 versus 417 ms; P<0.001). Each 10-ms increase in the QTc interval was associated with an increased risk of PAF after multivariate adjustments (odds ratio, 1.41; 95% confidence interval, 1.24–1.61; P<0.001). The optimal threshold value of QTc interval calculated by a receiver-operating characteristic curve was 438 ms, and the area under the curve was 0.73 in this data set. Conclusions— The QTc interval prolongation is potentially a strong and useful predictor for poststroke PAF.

Clinical Features and Functional Outcome of Stroke After Transient Ischemic Attack

BACKGROUND Transient ischemic attacks (TIAs) greatly increase the risk of stroke, but few reports have examined subsequent stroke in patients with history of TIA. METHODS This retrospective, hospital-based study included 506 consecutive patients with acute ischemic stroke who were admitted to our hospital. The clinical features and prognosis were compared between patients with and without TIA. Multiple logistic regression analysis was also performed to identify predictors for poor outcome. RESULTS Of 506 patients, 114 (22.5%) had a history of TIA. Compared to patients without previous TIAs (non-TIA group), patients with previous TIAs (TIA group) were significantly more likely to have hypertension (76.3% vs 64.3%; P = .016), dyslipidemia (57.0% vs 41.1%; P = .003), chronic kidney disease (28.1% v 15.1%; P = .001), intracranial major artery stenosis (51.8% vs 36.2%; P = .018), and large artery atherothrombosis (43.9% vs 28.3%; P = .002). There was no difference in the previous use of antithrombotic medications between the groups (36.0% vs 35.2%; P = .881). Although stroke severity on admission was similar, poor functional outcome (modified Rankin Scale score ≥4) was significantly more frequent in the TIA group, and history of TIA was an independent determinant of unfavorable outcome on multiple logistic regression analysis (odds ratio 1.46; 95% confidence interval 1.02-2.10; P = .041). CONCLUSIONS Atherothrombotic stroke with concomitant vascular risk factors were more frequent in the stroke patients with than without previous TIA. Antithrombotic therapy was conducted only in one-third of the patients even after TIA. The stroke patients with history of TIA were at great risk of disabling stroke.

Research Article: Clinical Characteristics of Isolated Anterior Cerebral Artery Territory Infarction Due to Arterial Dissection

BACKGROUND Isolated brain infarction in the anterior cerebral artery (ACA) territory is rare, and its etiology has not yet been fully elucidated. Thus, we aimed to determine the etiologic and clinical characteristics of patients with isolated ACA territory infarction due to arterial dissection. METHODS Of 2315 patients with acute cerebral infarction admitted to our hospital between April 2007 and September 2013, 34 patients (1.5%; 28 men, 6 women; mean age, 65 ± 15 years) suffered isolated ACA territory infarction. We performed cranial magnetic resonance (MR) imaging and MR angiography for all the patients. Whenever possible, we also performed 3-dimensional computed tomography angiography, digital subtraction angiography, and MR cisternography to diagnose the stroke subtype. RESULTS The stroke subtypes of the 34 patients with isolated ACA territory infarction were atherothrombotic infarction, cardioembolic infarction, arterial dissection, and unclassified in 11 patients (32%), 11 patients (32%), 11 patients (32%), and 1 patient (3%), respectively. The mean ages at onset were 48 ± 9 and 72 ± 11 years in the dissection and nondissection groups, respectively (P < .001). Headaches were present at onset in 4 patients (36%) and 1 patient (4%) with and without dissection, respectively (P = .026). Blood pressure at onset was significantly higher among patients with dissection (systolic, 179 ± 34 mm Hg; diastolic, 102 ± 17 mm Hg) than among patients without dissection (systolic, 155 ± 30 mm Hg; diastolic, 86 ± 21 mm Hg; P < .05), and d-dimer values were significantly lower among patients with dissection (P = .034). Favorable clinical outcome (modified Rankin Scale score, 0-2) at discharge was achieved in 9 patients (82%) and 10 patients (43%) with and without dissection, respectively (P = .035). CONCLUSIONS Patients with isolated ACA territory infarction demonstrated a relatively high frequency of dissection (32%). Patients with dissection were younger, had a higher frequency of headaches, and demonstrated more favorable prognoses than patients without dissection.

Cardioembolic Stroke is Frequent in Late Recurrence After Transient Ischemic Attack

BACKGROUND Transient ischemic attack (TIA) is often followed by a stroke episode. Differences between early and late recurrent stroke, however, have not been elucidated. METHODS We enrolled 133 consecutive patients with acute ischemic stroke who presented to our hospital and had previously been diagnosed with TIA. They were divided into 5 groups according to the interval between TIA and subsequent stroke: <48 hours (group 1); 48 hours to 1 week (group 2); 1 week to 1 month (group 3); 1 month to 3 months (group 4); and >3 months (group 5). Patients who underwent recurrent stroke within and after 1 week subsequent to TIA (the early and late recurrence groups, respectively) were compared with regard to clinical findings. RESULTS Of the 133 patients, 46 (34.6%) were in group 1, 29 (21.8%) in group 2, 23 (17.3%) in group 3, 18 (13.5%) in group 4, and 17 (12.8%) in group 5. Most of the noncardioembolic strokes were observed shortly after TIA, while the percentage of cardioembolic stroke remained high even after long post-TIA periods. The prevalence of atrial fibrillation (AF) was higher in the late recurrence group than in the early recurrence group (41.4% v 24.0%, P = .033). Among 42 patients with AF, 12 (28.6%) were newly diagnosed at the time of stroke. CONCLUSIONS The frequency of cardioembolic stroke did not decline as time after TIA passed. More than one quarter of AF patients had been asymptomatic before stroke, suggesting the need for repeated examinations to detect AF in patients with TIA of unknown etiology.

Differences in Endothelial Function between Ischemic Stroke Subtypes

BACKGROUND Endothelial dysfunction plays a key role in the development of ischemic stroke. However, the relationship between endothelial function and stroke subtypes has not been thoroughly examined. METHODS We measured the percentage of brachial flow-mediated vasodilatation (%FMD) in 62 patients with chronic stroke and 13 age- and sex-matched control patients. Patients with stroke included those classified into large artery atherosclerosis (LAA), cardioembolism (CE), and small vessel occlusion (SVO) according to the criteria of the Trial of ORG 10172 in Acute Stroke Treatment classification. RESULTS %FMD was significantly lower in the patients with any of LAA, CE, and SVO than in the control patients. %FMD was also significantly lower in men than in women as well as in patients with than without hypertension or diabetes mellitus. After adjustment for confounding factors, the patients with LAA and CE but not SVO had lower %FMD compared to the controls. CONCLUSIONS Our results suggest that endothelial function in conduit artery was impaired in patients with LAA and CE regardless with or without concomitant vascular risk factors.

Clinical Features of Ischemic Stroke during Treatment with Dabigatran: An Association between Decreased Severity and a Favorable Prognosis.

OBJECTIVE Anticoagulation therapy with warfarin is associated with a favorable prognosis in ischemic stroke. Dabigatran, a new oral anticoagulant, is widely used to prevent ischemic stroke in non-valvular atrial fibrillation (NVAF) patients. However, its association with decreased severity and a favorable prognosis once ischemic stroke has occurred remains unknown. METHODS We retrospectively reviewed all the patients with NVAF-associated ischemic stroke admitted to our hospital from April 2011 to December 2014 and included those who received dabigatran therapy. We assessed whether the patients were under regular use of the drug or discontinuance and classified them into 2 groups, the treatment and discontinuation groups. Clinical data, including the age, sex, ASCOD stroke phenotype, NVAF type, prescribed drug dose, comorbidities, CHADS2 score, renal function, National Institute of Health Stroke Scale (NIHSS) score on admission, modified Rankin scale (mRS) score at discharge, D-dimer, and brain natriuretic peptide, were investigated and compared between the groups. RESULTS Nine patients were under regular dabigatran therapy, and 6 were under discontinuance of the drug. The age, sex, ASCOD stroke phenotype, NVAF type, comorbidities, renal function, and CHADS2 scores did not differ between the 2 groups; however, the NIHSS scores were significantly lower in the treatment group. The mRS scores at discharge were additionally decreased in the treatment group. Moreover, the D-dimer scores were lower in the treatment group, thus suggesting a possible role in the decreased stroke severity. CONCLUSION Dabigatran may therefore decrease the severity of ischemic stroke, even if ischemic stroke occurs.

Functional Outcomes of Decompressive Craniectomy in Patients with Malignant Middle Cerebral Artery Infarction and Their Association with Preoperative Thalamus Deformation: An Analysis of 12 Patients.

Objective Decompressive craniectomy (DC) in patients with malignant middle cerebral artery (MCA) infarction is known to decrease the mortality rate. However, the functional outcomes (communication and oral intake) of this procedure remain unclear. Most patients with malignant MCA infarction exhibit a loss of consciousness, which may be principally governed by the thalamus. We herein investigated the functional outcomes of DC at 90 days after the onset of malignant MCA infarction and their association with preoperative thalamus deformation, which can occur due to pressure and edema. Methods Twelve of 2,692 patients with acute cerebral infarction were diagnosed with malignant MCA infarction and underwent DC. We evaluated preoperative thalamus damage using brain computed tomography and its association with communication and oral intake abilities and the modified Rankin Scale (mRS) and Barthel index scores at 90 days after stroke onset. Results The mRS score at 90 days was 0-4 in five patients. Seven patients could communicate immediately after surgery, while five could do so by 90 days. Five patients were able to resume the oral intake of food at 90 days. All patients with preoperative thalamus deformation showed a poor recovery, while those with absent or slight preoperative thalamus deformation showed a good recovery. Conclusion Patients with preoperative thalamus deformation caused by pressure and edema show a poor oral intake and communication abilities after DC, suggesting that preoperative thalamus deformation is a predictor of poor functional outcomes after DC in patients with malignant MCA infarction.

The Exacerbation of Hemicrania Continua Mimics Trigeminal Neuralgia

We report the case of a 46-year-old man with hemicrania continua presenting as exacerbations mimicking trigeminal neuralgia. The patient was tentatively diagnosed with trigeminal neuralgia, and treatment with various combinations of drugs was performed after the onset of pain. However, when the condition of the patient did not improve, we suspected hemicrania continua, and treatment with indomethacin was initiated. There was a marked alleviation of his pain within 24 hours. Thus, clinicians should be aware that the duration and frequency of exacerbations of hemicrania continua are variable.

Recurrent Cerebral Infarction Due to Benign Uterine Myoma

The hypercoagulable state in patients with cancer has been shown to be closely associated with ischemic stroke. However, it is unlikely that benign tumors are related to stroke. The development of benign uterine tumors is common in middle-aged women. Previous studies have shown cases of ischemic stroke with benign uterine tumor, but the causal relationship between these 2 remain unknown. We report a case of recurrent ischemic stroke in a middle-aged woman who had a benign uterine tumor. After excision, there was no recurrence for 2 years. Microemboli detection, clinical course and histological findings support a relationship between uterine tumor and ischemic stroke.