Prediction of Early Recanalization after Intravenous Thrombolysis in Patients with Large-Vessel Occlusion / 대한뇌졸중학회지

Background@#and Purpose We aimed to develop a model predicting early recanalization after intravenous tissue plasminogen activator (t-PA) treatment in large-vessel occlusion. @*Methods@#Using data from two different multicenter prospective cohorts, we determined the factors associated with early recanalization immediately after t-PA in stroke patients with large-vessel occlusion, and developed and validated a prediction model for early recanalization. Clot volume was semiautomatically measured on thin-section computed tomography using software, and the degree of collaterals was determined using the Tan score. Follow-up angiographic studies were performed immediately after t-PA treatment to assess early recanalization. @*Results@#Early recanalization, assessed 61.0±44.7 minutes after t-PA bolus, was achieved in 15.5% (15/97) in the derivation cohort and in 10.5% (8/76) in the validation cohort. Clot volume (odds ratio [OR], 0.979; 95% confidence interval [CI], 0.961 to 0.997; P=0.020) and good collaterals (OR, 6.129; 95% CI, 1.592 to 23.594; P=0.008) were significant factors associated with early recanalization. The area under the curve (AUC) of the model including clot volume was 0.819 (95% CI, 0.720 to 0.917) and 0.842 (95% CI, 0.746 to 0.938) in the derivation and validation cohorts, respectively. The AUC improved when good collaterals were added (derivation cohort: AUC, 0.876; 95% CI, 0.802 to 0.950; P=0.164; validation cohort: AUC, 0.949; 95% CI, 0.886 to 1.000; P=0.036). The integrated discrimination improvement also showed significantly improved prediction (0.097; 95% CI, 0.009 to 0.185; P=0.032). @*Conclusions@#The model using clot volume and collaterals predicted early recanalization after intravenous t-PA and had a high performance. This model may aid in determining the recanalization treatment strategy in stroke patients with large-vessel occlusion.

Prediction of Early Recanalization after Intravenous Thrombolysis in Patients with Large-Vessel Occlusion / 대한뇌졸중학회지

Background@#and Purpose We aimed to develop a model predicting early recanalization after intravenous tissue plasminogen activator (t-PA) treatment in large-vessel occlusion. @*Methods@#Using data from two different multicenter prospective cohorts, we determined the factors associated with early recanalization immediately after t-PA in stroke patients with large-vessel occlusion, and developed and validated a prediction model for early recanalization. Clot volume was semiautomatically measured on thin-section computed tomography using software, and the degree of collaterals was determined using the Tan score. Follow-up angiographic studies were performed immediately after t-PA treatment to assess early recanalization. @*Results@#Early recanalization, assessed 61.0±44.7 minutes after t-PA bolus, was achieved in 15.5% (15/97) in the derivation cohort and in 10.5% (8/76) in the validation cohort. Clot volume (odds ratio [OR], 0.979; 95% confidence interval [CI], 0.961 to 0.997; P=0.020) and good collaterals (OR, 6.129; 95% CI, 1.592 to 23.594; P=0.008) were significant factors associated with early recanalization. The area under the curve (AUC) of the model including clot volume was 0.819 (95% CI, 0.720 to 0.917) and 0.842 (95% CI, 0.746 to 0.938) in the derivation and validation cohorts, respectively. The AUC improved when good collaterals were added (derivation cohort: AUC, 0.876; 95% CI, 0.802 to 0.950; P=0.164; validation cohort: AUC, 0.949; 95% CI, 0.886 to 1.000; P=0.036). The integrated discrimination improvement also showed significantly improved prediction (0.097; 95% CI, 0.009 to 0.185; P=0.032). @*Conclusions@#The model using clot volume and collaterals predicted early recanalization after intravenous t-PA and had a high performance. This model may aid in determining the recanalization treatment strategy in stroke patients with large-vessel occlusion.

Plasma Fibroblast Growth Factor 23 Concentration Is Associated with Intracranial Cerebral Atherosclerosis in Acute Ischemic Stroke Patients

Association of MicroRNA Biogenesis Genes Polymorphisms with Ischemic Stroke Susceptibility and Post-Stroke Mortality / 대한뇌졸중학회지

BACKGROUND AND PURPOSE: MicroRNA (miRNA) expression has been examined in multiple conditions, including various cancers, neurological diseases, and cerebrovascular diseases, particularly stroke. Existing evidence indicates that miRNA biosynthesis and function play crucial roles in ischemic stroke physiology and pathology. In this study, we selected six known polymorphisms in miRNA-biogenesis genes; DICER rs13078A>T, rs3742330A>G; DROSHA rs10719T>C, rs6877842G>C; Ran GTPase (RAN) rs14035C>T; exportin 5 (XPO5) rs11077A>C. METHODS: We analyzed the associations between these polymorphisms and disease status and clinical factors in 585 ischemic stroke patients and 403 controls. Genotyping was performed with the polymerase chain reaction-restriction fragment length polymorphism method. RESULTS: The DICER rs3742330A>G (AA vs. AG+GG: adjusted odds ratio [AOR], 1.360; 95% confidence interval [CI], 1.024 to 1.807; P=0.034) and DROSHA rs10719T>C polymorphisms (TT vs. CC: AOR, 2.038; 95% CI, 1.113 to 3.730; P=0.021) were associated with ischemic stroke prevalence. During a mean follow-up of 4.80±2.11 years, 99 (5.91%) of the stroke patients died. In multivariate Cox proportional hazard regression models, a significant association was found between RAN rs14035 and survival of large artery disease patients with ischemic stroke (CC vs. TT: adjusted hazard ratio, 5.978; P=0.015). CONCLUSIONS: An association was identified between the DICER and DROSHA polymorphisms and ischemic stroke. Specifically, polymorphisms (rs3742330 and rs10719) were more common in stroke patients, suggesting that they may be associated with an increased risk of ischemic stroke.

Interarm Blood Pressure Difference is Associated with Early Neurological Deterioration, Poor Short-Term Functional Outcome, and Mortality in Noncardioembolic Stroke Patients

BACKGROUND AND PURPOSE: Interarm differences in the systolic and diastolic blood pressures (IASBD and IADBD, respectively) are found in various populations, including stroke patients, but their significance for stroke outcomes has rarely been reported. We aimed to determine the associations of IASBD and IADBD with early neurological deterioration (END), functional outcome, and mortality. METHODS: This study included 1,008 consecutive noncardioembolic cerebral infarction patients who were admitted within 24 hours of onset and had automatic measurements of blood pressures in the bilateral arms. END was assessed within 72 hours of stroke onset according to predefined criteria. A poor functional outcome was defined as a score on the modified Rankin Scale ≥3 at 3 months after the index stroke. All-cause mortality was also investigated during a median follow-up of 24 months. The absolute difference of blood pressure measurements in both arms were used to define IASBD and IADBD. RESULTS: END occurred in 15.3% (155/1,008) of the patients. A multivariate analysis including sex, age, and variables for which the p value was < 0.1 in a univariate analysis revealed that IASBD ≥10 mm Hg was significantly associated with END [odds ratio (OR)=1.75, 95% CI=1.02–3.01]. IADBD ≥10 mm Hg was also related to END (OR=3.11, 95% CI=1.61–5.99). Moreover, having both IASBD ≥10 mm Hg and IADBD ≥10 mm Hg was related to a poor functional outcome (OR=2.67, 95% CI=1.36–5.35) and mortality (hazard ratio=7.67, 95% CI=3.76–12.83) even after adjusting for END. CONCLUSIONS: This study suggests that an interarm blood pressure difference of ≥10 mm Hg could be a useful indicator for the risks of END, poor functional outcome, and mortality.

Cerebral Venous Thrombosis Presenting in Pregnancy with Thrombocytosis and Janus Kinase 2 Valine-to-Phenylalanine Mutation

A 30-year-old woman in her first pregnancy was admitted with headache and horizontal diplopia indicating left abducens nerve palsy. Brain magnetic resonance imaging revealed a cerebral venous thrombosis. She had thrombocytosis in the peripheral blood, and a genetic test for thrombocytosis revealed the presence of the valine-to-phenylalanine (V617F) mutation of the Janus kinase 2 (JAK2) gene. Treatment with low-molecular-weight heparin resolved her symptoms of headache and diplopia. The presence of genetic disorders such as the JAK2-V617F gene mutation should be assessed in patients with cerebral venous thrombosis and coexisting thrombocytosis.

Infarct Core Expansion on Computed Tomography before and after Intravenous Thrombolysis

PURPOSE: Infarct core can expand rapidly in acute stroke patients receiving intravenous tissue plasminogen activator (IV t-PA). We investigated changes in the extent of infarct core during IV t-PA treatment, and explored the associative factors of this infarct core expansion in patients with proximal artery occlusion. MATERIALS AND METHODS: We included patients who were considered for sequential intra-arterial therapy (IAT) due to occlusion of intracranial proximal artery after IV t-PA. Patients who had a baseline Alberta Stroke Program Early Computed Tomography (CT) Score (ASPECTS) ≥6 and who underwent two consecutive CT scans before and shortly after IV t-PA infusion were enrolled. Patients were classified into no, moderate, and marked expansion groups based on decreases in ASPECTS (0–1, 2–3, and ≥4, respectively) on follow-up CT. Collateral status was graded using CT angiography. RESULTS: Of the 104 patients, 16 (15.4%) patients showed moderate and 13 (12.5%) patients showed marked infarct core expansion on follow-up CT scans obtained at 71.1±19.1 min after baseline CT scan. Sixteen (15.4%) patients had an ASPECTS value < 6 on the follow-up CT. None of the patients with marked expansion were independent at 3 months. Univariate analysis and ordinal logistic regression analysis demonstrated that the infarct core expansion was significantly associated with collateral status (p < 0.001). CONCLUSION: Among patients who were considered for IAT after IV t-PA treatment, one out of every seven patients exhibited marked expansion of infarct core on follow-up CT before IAT. These patients tend to have poor collaterals and poor outcomes despite rescue IAT.

Post lumbar puncture headache: Case report of a serious adverse event in first-in-human study

A lumbar puncture can be used to measure the concentrations of drugs and/or pharmacodynamic biomarkers during clinical trials of central nervous system drugs. We report a case of a post lumbar puncture headache (PLPH) in a first-in-human study, which was reported as a serious adverse event. A 20-year-old man received 200 mg of the investigational product (IP) for 7 days and underwent a lumbar puncture for cerebrospinal fluid sampling before IP administration (Day 1, pre-dose) and after 7 days and multiple IP administrations (Day 7, 1 hour post-dose). After discharge on Day 8, the subject complained of headache, nausea, vomiting, neck stiffness, and numbness of the extremities. The symptoms occurred when he got up and disappeared after he remained in the supine position for several minutes. Five days later, he visited the neurology clinic of the main hospital. The neurologist recommended hospitalization for further evaluation and symptom management, and the subject was then admitted to the hospital. There were no abnormal findings in vital signs, laboratory results, or brain-computed tomography. His symptoms disappeared during the hospitalization period. It was important to distinguish whether the headache was IP-related or lumbar puncture-related. Therefore, knowledge of clinical characteristics and differential diagnosis of PLPH is paramount. Furthermore, if severe PLPH occurs, a consultation with a neurologist and imaging studies should be considered for a differential diagnosis of PLPH.

Total Cerebral Small-Vessel Disease Score is Associated with Mortality during Follow-Up after Acute Ischemic Stroke

BACKGROUND AND PURPOSE: The recently developed total cerebral small-vessel disease (CSVD) score might appropriately reflect the total burden or severity of CSVD. We investigated whether the total CSVD score is associated with long-term outcomes during follow-up in patients with acute ischemic stroke. METHODS: In total, 1,096 consecutive patients with acute ischemic stroke who underwent brain magnetic resonance imaging were enrolled. We calculated the total CSVD score for each patient after determining the burden of cerebral microbleeds (CMBs), high-grade white-matter hyperintensities (HWHs), high-grade perivascular spaces (HPVSs), and asymptomatic lacunar infarctions (ALIs). We recorded the date and cause of death for all of the patients using data from the Korean National Statistical Office. We compared the long-term mortality rate with the total CSVD score using Cox proportional-hazards models. RESULTS: CMBs were found in 26.8% of the subjects (294/1,096), HWHs in 16.4% (180/1,096), HPVSs in 19.3% (211/1,096), and ALIs in 38.0% (416/1,096). After adjusting for age, sex, and variables that were significant at p<0.1 in the univariate analysis, the total CSVD score was independently associated with long-term death from all causes [hazard ratio (HR)=1.18 per point, 95% confidence interval (CI)=1.07–1.30], ischemic stroke (HR=1.20 per point, 95% CI=1.01–1.42), and hemorrhagic stroke (HR=2.05 per point, 95% CI=1.30–3.22), but not with fatal cardiovascular events (HR=1.17 per point, 95% CI=0.82–1.67). CONCLUSIONS: The total CSVD score is a potential imaging biomarker for predicting mortality during follow-up in patients with acute ischemic stroke.

Gray-Matter Volume Estimate Score: A Novel Semi-Automatic Method Measuring Early Ischemic Change on CT / 대한뇌졸중학회지

BACKGROUND AND PURPOSE: We developed a novel method named Gray-matter Volume Estimate Score (GRAVES), measuring early ischemic changes on Computed Tomography (CT) semi-automatically by computer software. This study aimed to compare GRAVES and Alberta Stroke Program Early CT Score (ASPECTS) with regards to outcome prediction and inter-rater agreement. METHODS: This was a retrospective cohort study. Among consecutive patients with ischemic stroke in the anterior circulation who received intra-arterial therapy (IAT), those with a readable pretreatment CT were included. Two stroke neurologists independently measured both the GRAVES and ASPECTS. GRAVES was defined as the percentage of estimated hypodense lesion in the gray matter of the ipsilateral hemisphere. Spearman correlation analysis, receiver operating characteristic (ROC) comparison test, and intra-class correlation coefficient (ICC) comparison tests were performed between GRAVES and ASPECTS. RESULTS: Ninety-four subjects (age: 68.7+/-10.3; male: 54 [54.9%]) were enrolled. The mean GRAVES was 9.0+/-8.9 and the median ASPECTS was 8 (interquartile range, 6-9). Correlation between ASPECTS and GRAVES was good (Spearman's rank correlation coefficient, 0.642; P<0.001). ROC comparison analysis showed that the predictive value of GRAVES for favorable outcome was not significantly different from that of ASPECTS (area under curve, 0.765 vs. 0.717; P=0.308). ICC comparison analysis revealed that inter-rater agreement of GRAVES was significantly better than that of ASPECTS (0.978 vs. 0.895; P<0.001). CONCLUSIONS: GRAVES had a good correlation with ASPECTS. GRAVES was as good as ASPECTS in predicting a favorable clinical outcome, but was better than ASPECTS regarding inter-rater agreement. GRAVES may be used to predict the outcome of IAT.

Gray-Matter Volume Estimate Score: A Novel Semi-Automatic Method Measuring Early Ischemic Change on CT / 대한뇌졸중학회지

BACKGROUND AND PURPOSE: We developed a novel method named Gray-matter Volume Estimate Score (GRAVES), measuring early ischemic changes on Computed Tomography (CT) semi-automatically by computer software. This study aimed to compare GRAVES and Alberta Stroke Program Early CT Score (ASPECTS) with regards to outcome prediction and inter-rater agreement. METHODS: This was a retrospective cohort study. Among consecutive patients with ischemic stroke in the anterior circulation who received intra-arterial therapy (IAT), those with a readable pretreatment CT were included. Two stroke neurologists independently measured both the GRAVES and ASPECTS. GRAVES was defined as the percentage of estimated hypodense lesion in the gray matter of the ipsilateral hemisphere. Spearman correlation analysis, receiver operating characteristic (ROC) comparison test, and intra-class correlation coefficient (ICC) comparison tests were performed between GRAVES and ASPECTS. RESULTS: Ninety-four subjects (age: 68.7+/-10.3; male: 54 [54.9%]) were enrolled. The mean GRAVES was 9.0+/-8.9 and the median ASPECTS was 8 (interquartile range, 6-9). Correlation between ASPECTS and GRAVES was good (Spearman's rank correlation coefficient, 0.642; P<0.001). ROC comparison analysis showed that the predictive value of GRAVES for favorable outcome was not significantly different from that of ASPECTS (area under curve, 0.765 vs. 0.717; P=0.308). ICC comparison analysis revealed that inter-rater agreement of GRAVES was significantly better than that of ASPECTS (0.978 vs. 0.895; P<0.001). CONCLUSIONS: GRAVES had a good correlation with ASPECTS. GRAVES was as good as ASPECTS in predicting a favorable clinical outcome, but was better than ASPECTS regarding inter-rater agreement. GRAVES may be used to predict the outcome of IAT.

Association between Aortic Atheroma and Cerebral Small Vessel Disease in Patients with Ischemic Stroke / 대한뇌졸중학회지

BACKGROUND AND PURPOSE: Cerebral small vessel disease (SVDs) are related with large artery atherosclerosis. However, the association between aortic atheroma (AA) and cerebral small vessel disease has rarely been reported. This study evaluated the relationship between presence and burden of AAs and those of SVDs in patients with acute ischemic stroke. METHODS: We included 737 consecutive patients who underwent transesophageal echocardiography (TEE) and brain magnetic resonance imaging (MRI) for evaluation of acute stroke. AA subtypes were classified as complex aortic plaque (CAP) and simple aortic plaque (SAP). Presence and burden of SVDs including cerebral microbleeds (CMBs), white matter hyperintensities (WMHs), perivascular spaces (PVSs), asymptomatic lacunar infarctions (ALIs), and total SVD score, were investigated. RESULTS: AA was found by TEE in 360 (48.8%) patients including 11.6% with CAP and 37.2% with SAP. One or more types of SVDs was found in 269 (36.4%) patients. In multivariable analysis, presence of CMBs (odds ratio [OR] 4.68), high-grade WMHs (OR 3.13), high-grade PVSs (OR 3.35), and ALIs (OR 4.24) were frequent in patients with AA than those without AA. Each 1-point increase in total SVD score increased the odds of presence of CAP (OR 1.94, 95% confidence interval (CI) 1.44-1.85) and SAP (OR 1.54, 95% CI 1.35-1.75). CONCLUSIONS: In this study, patients with AA frequently had cerebral SVDs. Larger burden of AA was associated with advanced cerebral SVDs. Our findings give an additional information for positive relationship with systemic atherosclerosis and coexisting cerebral SVDs in acute ischemic stroke patients.

The Effect of Pulsatility Index on Infarct Volume in Acute Lacunar Stroke

PURPOSE: Lacunar stroke, in the context of small vessel disease, is a type of cerebral infarction caused by occlusion of a penetrating artery. Pulsatility index (PI) is an easily measurable parameter in Transcranial Doppler ultrasound (TCD) study. PI reflects distal cerebral vascular resistance and has been interpreted as a surrogate marker of small vessel disease. We hypothesized that an increased PI, a marker of small vessel disease, might be associated with a larger infarct volume in acute lacunar stroke. MATERIALS AND METHODS: This study included 64 patients with acute lacunar stroke who underwent TCD and brain MRI. We evaluated the association between the mean PI value of bilateral middle cerebral arteries and infarct volume on diffusion-weighted MRI using univariate and multivariate linear regression. RESULTS: The mean infarct volume and PI were 482.18±406.40 mm3 and 0.86±0.18, respectively. On univariate linear regression, there was a significant positive association between PI and infarct volume (p=0.001). In the multivariate model, a single standard deviation increase of PI (per 0.18) was associated with an increase of 139.05 mm3 in infarct volume (95% confidence interval, 21.25 to 256.85; p=0.022). CONCLUSION: We demonstrated that PI was an independent determinant of infarct volume in acute lacunar stroke. The PI value measured in acute stroke may be a surrogate marker of the extent of ischemic injury.

Acute Cerebral Infarction Associated with Inherited Protein S Deficiency

Coagulopathies are a relatively common cause of young-age stroke. We present herein a 15-year-old male who was admitted for acute cerebral infarction with dysarthria and weakness of the right side. He had previously been diagnosed with autosomal dominant protein-S deficiency. His left internal carotid artery was totally occluded. Emergency mechanical thrombolysis resulted in recanalization of that occluded artery and consequent improvement in symptoms. The patient was discharged with an oral anticoagulant.

Development of Smartphone Application That Aids Stroke Screening and Identifying Nearby Acute Stroke Care Hospitals

PURPOSE: The benefits of thrombolytic treatment are time-dependent. We developed a smartphone application that aids stroke patient self-screening and hospital selection, and may also decrease hospital arrival time. MATERIALS AND METHODS: The application was developed for iPhone and Android smartphones. Map data for the application were adopted from the open map. For hospital registration, a web page (http://stroke119.org) was developed using PHP and MySQL. RESULTS: The Stroke 119 application includes a stroke screening tool and real-time information on nearby hospitals that provide thrombolytic treatment. It also provides information on stroke symptoms, thrombolytic treatment, and prescribed actions when stroke is suspected. The stroke screening tool was adopted from the Cincinnati Prehospital Stroke Scale and is displayed in a cartoon format. If the user taps a cartoon image that represents abnormal findings, a pop-up window shows that the user may be having a stroke, informs the user what to do, and directs the user to call emergency services. Information on nearby hospitals is provided in map and list views, incorporating proximity to the user's location using a Global Positioning System (a built-in function of smartphones). Users can search for a hospital according to specialty and treatment levels. We also developed a web page for hospitals to register in the system. Neurology training hospitals and hospitals that provide acute stroke care in Korea were invited to register. Seventy-seven hospitals had completed registration. CONCLUSION: This application may be useful for reducing hospital arrival times for thrombolytic candidates.

Distribution of Cerebral Microbleeds Determines Their Association with Impaired Kidney Function

BACKGROUND AND PURPOSE: Cerebral microbleeds (CMBs) are associated with various pathologies of the cerebral small vessels according to their distribution (i.e., cerebral amyloid angiopathy or hypertensive angiopathy). We investigated the association between CMB location and kidney function in acute ischemic stroke patients. METHODS: We enrolled 1669 consecutive patients with acute ischemic stroke who underwent gradient-recalled echo brain magnetic resonance imaging. Kidney function was determined using the estimated glomerular filtration rate (eGFR). CMBs were classified into strictly lobar, strictly nonlobar (i.e., only deep or infratentorial), and a combination of both lobar and nonlobar. Multinomial logistic regression analyses were used to determine the factors associated with the existence of CMBs according to their location. RESULTS: The patients were aged 66+/-12 years (mean+/-standard deviation), and 61.9% (1033/1669) of them were male. CMBs were found in 27.0% (452/1669) of the patients. The stroke subtypes of small-artery occlusion and cardioembolism occurred more frequently in those with strictly nonlobar CMBs (10.8%) and strictly lobar CMBs (48.8%), respectively. The mean eGFR was lower in the strictly nonlobar CMBs group (72+/-28 mL/min/1.73 m2) and the both lobar and nonlobar CMBs group (72+/-25 mL/min/1.73 m2) than in the no-CMBs group (86+/-29 mL/min/1.73 m2). Multivariate multinomial logistic regression revealed that eGFR <60 mL/min/1.73 m2 was independently related to strictly nonlobar CMBs (odds ratio=2.63, p=0.001). CONCLUSIONS: Impaired kidney function is associated with strictly nonlobar CMBs. Our findings indicate that the distribution of CMBs should be considered when evaluating their relationships or prognoses.

Plasma Total Homocysteine Level Is Associated with the Pulsatility Index of Cerebral Arteries in Lacunar Infarction

PURPOSE: The pulsatility index (PI), measured by transcranial Doppler (TCD), is a surrogate marker for distal vascular resistance in cerebral arteries, and elevated plasma total homocysteine (tHcyt) is regarded as a cause of ischemic stroke, including lacunar infarction. We investigated the relationship between the PI of cerebral arteries and plasma tHcyt in patients with lacunar infarction. MATERIALS AND METHODS: Plasma tHcyt level and TCD examination were performed in 94 patients with lacunar infarction. Mean flow velocity (MFV) and PI were assessed at the ipsilateral middle cerebral artery (MCA) and contralateral MCA, relative to the infarction, and the basilar artery (BA). Multivariate regression analysis was conducted between log-transformed tHcyt levels (logHcyt) and the PI of individual arteries. RESULTS: There was a significant correlation between logHcyt and the PI in all tested arteries (ipsilateral MCA: r=0.21, p=0.03; contralateral MCA: r=0.21, p=0.04; BA: r=0.35, p=0.01). In multivariate regression analysis, this significance remained unchanged after adjusting for vascular risk factors, creatinine, hematocrit and platelet count (ipsilateral MCA: beta=0.26, p=0.01; contralateral MCA: beta=0.21, p=0.04; BA: beta=0.39, p=0.001). There was no significant association between logHcyt and MFV of individual arteries. CONCLUSION: A significant association between plasma tHcyt and the PI of cerebral arteries indicates that homocysteine plays a role in the increase of distal arterial resistance in lacunar infarction.

Cortical Deafness Caused by Bilateral Acute Middle Cerebral Artery Infarctions

Sudden bilateral hearing loss is mainly caused by peripheral otologic disorders or psychogenic origins. Bilateral temporal lobe infarcts can be one of the rare causes. We report a 50-year-old man presented with cortical deafness due to bilateral temporal lobe infarctions. He was admitted at hospital because he did not respond to any verbal questions or environmental sounds, although he understood written commands partially and spoke fluently. Brain MRI demonstrated ischemic infarcts in both temporal lobes involving primary auditory cortex.

Ischemic Stroke in Patients with Renal Transplantation / 대한뇌졸중학회지

BACKGROUND: Impaired renal function may contribute to development of stroke and small vessel pathology in the brain. We investigated whether stroke subtype, initial stroke severity, early neurologic outcomes, time to cerebral infarction occurrence, and the presence of small vessel pathology in the brain are different between patients with end stage renal disease (ESRD) and those with renal transplantation (RT). METHODS: A total of 57 consecutive de novo RT patients (RT group) and 120 patients undergoing dialysis due to ESRD (ESRD group) who developed a first-ever acute cerebral infarction were enrolled. We compared stroke subtypes based on the Trial of Org 10172 in Acute Stroke Treatment classification, the presence of small vessel pathology (cerebral microbleed, leukoaraiosis and silent lacunar infarction) on MRI, stroke severity based on the National Institutes of Health Stroke Scale (NIHSS) and in-hospital mortality between the groups. RESULTS: The stroke subtypes, NIHSS scores at admission and in-hospital mortality were not different between the two groups. On multivariate analysis, the presence of high grade periventricular white matter changes tended to be more frequently detected in the ESRD group than the RT (P=0.078). The time from starting dialysis to stroke was longer in the RT group (129.9+/-60.9 months) than in the ESRD group (51.1+/-46.1 months). CONCLUSIONS: The stroke patterns, severity and short term outcomes were not different between RT and ESRD. The risk of cerebral infarction and high grade periventricular white matter changes may be reduced after RT in patients with ESRD.

Classification of BMI Control Commands Using Extreme Learning Machine from Spike Trains of Simultaneously Recorded 34 CA1 Single Neural Signals

A recently developed machine learning algorithm referred to as Extreme Learning Machine (ELM) was used to classify machine control commands out of time series of spike trains of ensembles of CA1 hippocampus neurons (n=34) of a rat, which was performing a target-to-goal task on a two-dimensional space through a brain-machine interface system. Performance of ELM was analyzed in terms of training time and classification accuracy. The results showed that some processes such as class code prefix, redundancy code suffix and smoothing effect of the classifiers' outputs could improve the accuracy of classification of robot control commands for a brain-machine interface system.