Kenichiro Hira

L-Carnitine Enhances Axonal Plasticity and Improves White-Matter Lesions after Chronic Hypoperfusion in Rat Brain

Chronic cerebral hypoperfusion causes white-matter lesions (WMLs) with oxidative stress and cognitive impairment. However, the biologic mechanisms that regulate axonal plasticity under chronic cerebral hypoperfusion have not been fully investigated. Here, we investigated whether L-carnitine, an antioxidant agent, enhances axonal plasticity and oligodendrocyte expression, and explored the signaling pathways that mediate axonal plasticity in a rat chronic hypoperfusion model. Adult male Wistar rats subjected to ligation of the bilateral common carotid arteries (LBCCA) were treated with or without L-carnitine. L-carnitine-treated rats exhibited significantly reduced escape latency in the Morris water maze task at 28 days after chronic hypoperfusion. Western blot analysis indicated that L-carnitine increased levels of phosphorylated high-molecular weight neurofilament (pNFH), concurrent with a reduction in phosphorylated phosphatase tensin homolog deleted on chromosome 10 (PTEN), and increased phosphorylated Akt and mammalian target of rapamycin (mTOR) at 28 days after chronic hypoperfusion. L-carnitine reduced lipid peroxidation and oxidative DNA damage, and enhanced oligodendrocyte marker expression and myelin sheath thickness after chronic hypoperfusion. L-carnitine regulates the PTEN/Akt/mTOR signaling pathway, and enhances axonal plasticity while concurrently ameliorating oxidative stress and increasing oligodendrocyte myelination of axons, thereby improving WMLs and cognitive impairment in a rat chronic hypoperfusion model.

Bilateral Facial Nerve Palsy Due to Otitis Media Associated With Myeloperoxidase-Antineutrophil Cytoplasmic Antibody

Otitis media (OM) is well known as a common feature of proteinase 3 antineutrophil cytoplasmic antibody (PR3-ANCA)-related Wegener granulomatosis, but is a very rare condition in myeloperoxidase ANCA (MPO-ANCA)-related vasculitis. In addition, there have been a few reports showing an association of MPO-ANCA-positive OM with cranial polyneuropathy. In this report, we describe 2 patients with bilateral facial nerve palsy due to MPO-ANCA-related OM. One patient also had bilateral trigeminal neuropathy, pachymeningitis and MPO-ANCA-related glomerulonephritis, whereas the other showed isolated bilateral facial nerve palsy with OM. In both the patients, treatment with prednisolone and immune-suppressant drugs resulted in an improvement of OM and cranial polyneuropathy. Physicians should be aware that MPO-ANCA-positive OM can cause bilateral facial nerve palsy.

Emerging Risk Factors for Recurrent Vascular Events in Patients With Embolic Stroke of Undetermined Source

Background and Purpose— Underlying embolic causes diagnosed by transesophageal echocardiography could be implicated in mechanisms of embolic stroke of undetermined source. We aimed to explore factors, including underlying embolic causes, related to recurrent vascular events in embolic stroke of undetermined source. Methods— Patients who fulfilled the diagnostic criteria for embolic stroke of undetermined source and whose potential embolic sources were examined by transesophageal echocardiography were included. Recurrent vascular events, including ischemic stroke, cardiovascular and peripheral artery diseases, and vascular death, were retrospectively analyzed. Cox proportional hazards regression analysis was used to explore factors, including clinical characteristics, embolic causes on transesophageal echocardiography, and the Calcification in the Aortic Arch, Age, Multiple Infarction score (CAM), based on the degree of aortic arch calcification on chest radiograph (0–3 points), age (≥70 years; 1 point), and multiple infarctions on magnetic resonance imaging (multiple infarcts in 1, 2, or ≥3 territories of large intracranial arteries, 1, 2, or 3 points) associated with recurrent vascular events. Results— A total of 177 patients (age, 64.1±14.2 years; 127 men) were enrolled. Thirty-one patients had recurrent vascular events (follow-up, 3.5±2.7 years; annualized rate, 5.0% per person-year). Among embolic causes on transesophageal echocardiography, incidence of recurrent vascular events was high in patients with large aortic arch plaques (7.5% per person-year). Diabetes mellitus (hazard ratio, 2.56; 95% confidence interval, 1.23–5.32; P=0.012) and CAM score grade (hazard ratio, 2.29; 95% confidence interval, 1.11–4.72; P=0.026) predicted recurrent vascular events. Conclusions— History of diabetes mellitus and the CAM score could be novel risk factors for recurrent vascular events in embolic stroke of undetermined source.

Analysis of the Usefulness of the WORSEN Score for Predicting the Deterioration of Acute Ischemic Stroke

BACKGROUND Early neurological worsening is associated with increased mortality and long-term functional disability. We developed the WORSEN score for predicting whether patients with stroke will deteriorate during the week after stroke onset and investigated its usefulness. PATIENTS AND METHODS We retrospectively investigated the cases of 478 patients who were admitted to Juntendo University Hospital between April 2007 and March 2009. Neurological deterioration was defined as a worsening of 4 points or higher on the National Institute of Health Stroke Scale score within 1 week of admission. Based on a previous study, we developed the WORSEN score, which was derived from the following factors: wrong (poor) blood sugar control (W), old myocardial infarction (O), radiological findings (R), infarct size (S), elevated low-density lipoprotein cholesterol (E), and neurological findings (N). Next, we investigated the utility of this scoring system in 456 other patients who were admitted to Juntendo University Hospital and Juntendo Urayasu Hospital between October 2013 and December 2014. RESULTS First, we checked the utility of the WORSEN score for detecting worsening in cases of stroke. In the first patient group, deterioration was noted in 32.5% of the patients with scores higher than 3 points (sensitivity: .704 and specificity: .744). For checking reproductivity on using the second group, deterioration was detected in 36.1% of the patients with WORSEN scores higher than 3 points (sensitivity: .740 and specificity: .835). CONCLUSIONS Careful attention should be paid to patients with acute stroke with high WORSEN scores. The WORSEN score might become a valuable tool for detecting the neurological deterioration of ischemic stroke.

Impact of BNP on cryptogenic stroke without potential embolic sources on transesophageal echocardiography

BACKGROUND Clinical characteristics are important for determining the etiologies of embolic stroke, including patent foramen ovale and complex aortic plaques demonstrated on transesophageal echocardiography (TEE). This study sought to analyze the clinical signs of cryptogenic stroke (CS) without such embolic etiologies and to examine the association between CS and brain natriuretic peptide (BNP), which is currently unknown. METHODS Patients with CS after routine examinations who underwent TEE were included in this single-center observational study. Patients were classified into the potential embolic sources (PES) group (patients having PES on TEE) and the no potential embolic source (NPES) group. Patients were also categorized according to the tertile of BNP. RESULTS A total of 158 patients (age, 64.0 ± 13.9 years; 119 males) with CS were enrolled. The PES group had 108 (68%) patients, and the NPES group had 50 (32%). Hypertension was more common, and glucose, D-dimer, and BNP were higher in the NPES than in the PES group (p<0.05). NPES was independently associated with high-BNP tertile (OR: 5.61; 95% CI: 1.91 to 16.44; p=0.002). CONCLUSIONS BNP, an indicator of cardioembolism, was closely associated with NPES. Cardiogenic mechanisms may be implicated in the etiology of CS without potential embolic etiologies on TEE.

Adequate Adherence to Direct Oral Anticoagulant is Associated with Reduced Ischemic Stroke Severity in Patients with Atrial Fibrillation

BACKGROUND The impact of adherence to direct oral anticoagulants (DOACs) is unknown. We aimed to assess the effects of preceding anticoagulation treatment on neurologic severity at admission and functional outcomes at discharge in patients with atrial fibrillation (AF) who developed acute ischemic stroke. METHODS We retrospectively assessed consecutive patients with acute ischemic stroke and AF. Adherence to DOACs was assessed using the 4-item Morisky Medication Adherence Scale. Associations between preceding DOAC treatment and stroke severity at admission and functional outcomes at hospital discharge were examined. RESULTS Of 387 patients with AF and acute ischemic stroke, 248 (64.1%) were not administered an anticoagulant before stroke onset, 95 (24.5%) had subtherapeutic warfarin with an international normalized ratio less than 2 at the time of stroke, 16 (4.1%) had therapeutic warfarin, 6 (1.6%) had DOACs with nonadherence, and 22 (5.7%) had DOACs with adequate adherence. Multivariate analysis showed that DOAC treatment with adequate adherence was associated with lower odds of severe stroke (National Institute of Health Stroke Scale ≥10 at admission) (odds ratio, .24; 95% confidence interval, .03-.98; P = .04) and higher odds of excellent recovery (modified Rankin Scale score, 0-1 at discharge) (odds ratio, 4.89; 95% confidence interval, 1.51-20.6; P < .01) compared with no anticoagulation therapy. CONCLUSIONS Preceding DOAC treatment with adequate adherence has beneficial effects on stroke severity at admission and functional outcome at discharge in patients with AF. Hence, our results encourage an increased effort to bolster adherence to DOACs in patients with AF.

Analysis for usefulness of worsen score; The predicting score for the deterioration of acute ischemic stroke

・Careful attention should be paid to acute stroke patients with high WORSEN scores. Actually, patients with high WORSEN scores with low initial NIHSS scores need to be closely monitored in intensive care or acute stroke units. >For example, patients with high WORSEN scores can be managed with high volume infusion therapy, multiple types of anti-platelet therapy from the begging, and the bed rest level.

Age Stratification and Impact of Eicosapentaenoic Acid and Docosahexaenoic Acid to Arachidonic Acid Ratios in Ischemic Stroke Patients

Aim: We focused on the ratios of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) to arachidonic acid (AA) and explored the significance of these ratios relative to clinical characteristics by age in ischemic stroke patients. Methods: We enrolled patients with acute ischemic stroke who underwent radiological investigations and laboratory examinations, including measurement of serum EPA, DHA, and AA levels, and controls. Patients were classified according to age (< 65, 65–74, and ≥ 75 years) and the tertile of EPA/AA and DHA/AA ratios, and clinical aspects were compared with these factors. Results: We analyzed 373 patients (age 70.2 ± 13.4 years; 245 males) and 105 controls. Among stroke patients, patients aged < 65 years had the lowest EPA/AA (0.35 ± 0.23, p = 0.006) and DHA/AA (0.73 ± 0.27, p < 0.001) ratios. Compared with controls, patients aged < 65 years showed lower EPA/AA (vs. 0.49 ± 0.25, p < 0.001) and DHA/AA (vs. 0.82 ± 0.26, p = 0.009) ratios. From logistic regression analysis, the EPA/AA (odds ratio 0.18, 95% confidence interval 0.04–0.81, p = 0.026) and DHA/AA (odds ratio 0.09, 95% confidence interval 0.02–0.33, p < 0.001) ratios were inversely related to patients aged < 65 years. According to age-stratified analyses, we found an association of aortic arch calcification with a lower EPA/AA ratio for patients aged ≥ 75 years and an association of multiple infarctions and cerebral white matter lesions with a lower EPA/AA ratio for patients aged 65–74 years (p < 0.05). Conclusions: The ratios of EPA/AA and DHA/AA could be specific markers for younger stroke patients. The EPA/AA ratio may be related to aortic arch calcification for elderly stroke patients and to multiple infarctions and cerebral white matter disease for middle-aged stroke patients.