Difference in the Location and Risk Factors of Cerebral Microbleeds According to Ischemic Stroke Subtypes / 대한뇌졸중학회지

BACKGROUND AND PURPOSE: The location of cerebral microbleeds (CMBs) may differ according to ischemic stroke subtype, and the underlying pathomechanism may differ by their location. Here, we investigated the characteristics of CMBs according to various ischemic stroke subtypes to verify this issue. METHODS: Patients with acute ischemic stroke were consecutively included. The presence of CMBs was determined by gradient echo image sequence. The distribution of CMBs was classified as deep, lobar, or diffuse (both deep and lobar). The prevalence, risk factors, and distribution of CMBs were compared among patients with different stroke subtypes. Factors associated with the distribution of CMBs were investigated. RESULTS: Among the 1033 patients included in this study, ischemic stroke subtypes were classified as large artery atherosclerosis (LAA; n=432), small vessel occlusion (SVO; n=304), and cardioembolism (CE; n=297). The prevalence of CMBs was highest in patients with SVO (40.5%), followed by CE (33.0%) and LAA (24.8%; P<0.001). The locations of CMBs was different according to subtype (P=0.004). CE [odds ratio (OR)=1.85 (1.02-3.34); P=0.042] and the use of antithrombotics [OR=1.80 (1.10-2.94); P=0.019] were associated with lobar CMBs, and old age [OR=1.02 (1.00-1.04); P=0.015] and hypertension [OR=1.61 (1.08-2.40); P=0.020] were associated with deep CMBs. CONCLUSIONS: CMBs were frequently located in the lobar area in patients with CE. Previous use of antithrombotic agents is associated with lobar CMBs. The pathogenic mechanism of CMB may differ according to ischemic stroke subtype and location.

Impact of Vascular Risk Factors, Axial Medial Temporal Atrophy, White Matter Hyperintensity on Cognitive Outcome in Alzheimer's Diseases

BACKGROUND: There is epidemiologic evidence to support vascular disease as a possible cause of Alzheimer's dementia (AD). The primary aim of this study was to determine the prevalence of vascular risk factors (vRFs) with respect to various clinical measures, such as axial-rated medial temporal lobe atrophy (MTA), ischemic white-matter changes, and cognition. The secondary aim was to determine the most significant clinical measure associated with cognitive outcome. METHODS: The study subjects comprised 198 probable AD and 38 subjective memory impairment-no cognitive impairment controls (SMI-NCI), for whom medical data including history vRF-related blood tests, clinical dementia evaluation, cognitive assessment, and brain MRI, were available. The grading of white-matter hyperintensities (WMHs) was achieved using Fazekas' method. MTA was graded by two neurologists independently based on axial T1-weighted MRI images. The prevalence of risk factors for Koreans aged > or =65 years was reviewed for comparison. RESULTS: All vRFs except smoking were more severe in the AD group than in both the SMI-NCI group and Koreans aged > or =65 years, but the high prevalence of vRFs had no impact on WMH lesions, axial MTA, or cognitive outcome. Both white-matter changes and MTA were significantly worse in AD than in SMI-NCI (p<0.001). The degree of MTA was negatively correlated with WMH grade (p<0.001), but the severity of clinical dementia was correlated only with increased axial MTA in AD (Instrumental Activities of Daily Living and Clinical Dementia Rating scores, p<0.001; Clinical Dementia Rating-Sum of Boxes score, p<0.005). CONCLUSIONS: WMHs and axial MTA were significantly more severe in the AD group than in the SMI-NCI subjects. The findings of this study indicate that worsening of cognitive dysfunction in AD appears to be driven by MTA, which is evident even in axial MTA visual grading, irrespective of WMH severity and the presence of vRFs.

Peri-ictal Heart Rate Changes in Patients With Localization-Related Epilepsy

BACKGROUND: Epileptic seizures can be associated with changes in autonomic functions. This study evaluated heart rate (HR) changes at the transition from the preictal to the ictal state in patients with epileptic seizures, and investigated whether peri-ictal HR changes can help to predict electroencephalography (EEG) seizures prior to their onset. METHODS: We retrospectively studied 94 seizures in 33 patients who underwent video-EEG monitoring with scalp EEG and electrocardiography. The existence and initial timing of HR changes relative to the onset of EEG seizures were determined by analyzing consecutive RR-interval changes in 10-minute recordings. We evaluated the correlation between the peri-ictal HR changes and the type of localization-related epilepsy. RESULTS: Peri-ictal HR changes were documented in 70.2% (66/94) of all seizures, of which 62 were tachycardia (66.0%) and 4 were bradycardia (4.3%). Peri-ictal tachycardia occurred significantly with seizures as an ictal manifestation, more often in seizures with a right hemispheric onset than in those with a left hemispheric onset (77.4% vs. 50%, p=0.016). Peri-ictal HR changes were observed much earlier in seizures of mesial temporal lobe epilepsy (TLE) than in those of extratemporal lobe epilepsy (-54.4 s vs. -6.7 s, p<0.001). CONCLUSIONS: Peri-ictal HR changes were observed in 70.2% of seizures, 94% of which were tachycardia. These changes could be helpful in predicting seizure onset, especially in mesial TLE.

Predictive Factors of Neurologic Outcome in Patients With Hypoxic-Ischemic Encephalopathy After Cardiopulmonary Resuscitation

BACKGROUND: Cardiopulmonary resuscitation (CPR) can lead to various neurologic outcomes in patients with hypoxicischemic encephalopathy (HIE). This study investigated the usefulness of clinical markers and electroencephalography (EEG) in predicting the neurologic prognosis of HIE after CPR. METHODS: We reviewed the clinical findings of 51 patients with HIE, including the medical history, the duration from the onset of symptoms to the recovery of spontaneous circulation, Glasgow Coma Scale (GCS) and Full Outline of Unresponsiveness (FOUR) scores, and presence of seizure or status epilepticus. Patients were divided into three outcomes groups: death, persistent vegetative state, and recovering alertness and awareness. Digital EEG and visual and quantitative analyses were performed in each patient. For quantitative EEG (qEEG) analysis, we defined and compared the distance in the spatial band-power patterns and phase coherence patterns between healthy normal subjects and each patient. RESULTS: Patients with HIE showed a high mortality rate (54.9%, 28/51), and their neurologic prognosis was significantly related to the initial GCS and FOUR scores. In the qEEG analysis, patients' groups showed a prominent delta frequency band, and the healthy normal group presented a marked alpha predominance. As the severity decreased, the similarity in the spatial band-power pattern and functional connectivity pattern between normal subjects and patients increased. CONCLUSIONS: Low initial GCS and FOUR scores could be predictive of a poor neurologic prognosis in patients with HIE, and qEEG analysis might be a useful predictor of their neurologic outcomes.