Numbers of Stroke Patients and Stroke Subtypes According to Highest and Lowest Daily Temperatures in Seoul

BACKGROUND AND PURPOSE: There is conflicting evidence for whether or not the incidence of stroke is influenced by the daily temperature. The association between daily temperature and incidence of stroke is largely unknown in Korea. This study attempted to evaluate whether the maximum or minimum daily temperature is associated with increased numbers of strokes and stroke subtypes among Seoul residents. METHODS: We obtained the maximum and minimum daily temperatures in Seoul from the Korean Meteorological Administration between January 2005 and December 2014. Consecutive patients with acute stroke were registered who visited the emergency room or outpatient clinic in Soonchunhyang University Hospital, Seoul. The residential addresses of cases were restricted to within a 2-kilometer radius of this hospital. The stroke events were prospectively recorded with onset time, and were classified by subtypes. The categories of daily temperature were divided by 10℃ from the mean temperature. The mean daily number of strokes was calculated during the study period. One-way analysis of variance and Duncan's post-hoc test were applied to compare the number of strokes among the temperature groups. RESULTS: In total, 2,313 acute strokes were identified during the period: 1,643 ischemic strokes and 670 hemorrhagic strokes. The number of cases was significantly higher when the maximum daily temperature was >32℃ or ≤3℃ (p=0.048) or the minimum daily temperature was ≤-11.0℃ (p=0.020). The lowest maximum daily temperature was associated with increased instances of intracerebral hemorrhage (p=0.029) and small-vessel occlusion (p=0.013), while the highest maximum daily temperature was associated with an increased instance of large-artery atherosclerosis (p=0.045). CONCLUSIONS: The daily temperature had measurable and different associations with the number of strokes and strokes subtypes in Seoul, Korea.

Relation Between Left Atrial Enlargement and Stroke Subtypes in Acute Ischemic Stroke Patients

OBJECTIVE: Increased atrial size is frequently seen in ischemic stroke patients in clinical practice. There is controversy about whether left atrial enlargement (LAE) should be regarded as a risk factor for cerebral infarction. We investigated the association between indexed left atrial volume (LAVI) and conventional stroke risk factors as well as stroke subtypes in acute ischemic stroke patients. METHODS: One hundred eighty two acute cerebral infarction patients were included in this study. Brain magnetic resonance imaging and transthoracic echocardiography were done for all patients within 30 days of diagnosis of acute cerebral infarction. Echocardiographic LAE was identified when LAVI was more than 27 mL/m2. Stroke subtypes were classified by the Trial of Org 10171 in acute stroke treatment classification. RESULTS: There were significant differences between subjects with normal and increased LAVI in prevalence of stroke risk factors including atrial fibrillation (p = 0.001), hypertension (p = 0.000), valvular heart disease (p = 0.011) and previous stroke (p = 0.031). An increased LAVI was associated with cardioembolic subtype with an adjusted odds ratio was 6.749 (p = 0.002) compared with small vessel disease. CONCLUSION: Increased LAVI was more prevalent in those who had cardiovascular risk factors, such as atrial fibrillation, hypertension, valvular heart disease and history of previous stroke. LAE influenced most patients in all subtypes of ischemic stroke but was most prevalent in the cardioembolic stroke subtype. Increased LAVI might be a risk factor of cerebral infarction, especially in patients with cardioembolic stroke subtype.

Relation Between Left Atrial Enlargement and Stroke Subtypes in Acute Ischemic Stroke Patients

OBJECTIVE: Increased atrial size is frequently seen in ischemic stroke patients in clinical practice. There is controversy about whether left atrial enlargement (LAE) should be regarded as a risk factor for cerebral infarction. We investigated the association between indexed left atrial volume (LAVI) and conventional stroke risk factors as well as stroke subtypes in acute ischemic stroke patients. METHODS: One hundred eighty two acute cerebral infarction patients were included in this study. Brain magnetic resonance imaging and transthoracic echocardiography were done for all patients within 30 days of diagnosis of acute cerebral infarction. Echocardiographic LAE was identified when LAVI was more than 27 mL/m2. Stroke subtypes were classified by the Trial of Org 10171 in acute stroke treatment classification. RESULTS: There were significant differences between subjects with normal and increased LAVI in prevalence of stroke risk factors including atrial fibrillation (p = 0.001), hypertension (p = 0.000), valvular heart disease (p = 0.011) and previous stroke (p = 0.031). An increased LAVI was associated with cardioembolic subtype with an adjusted odds ratio was 6.749 (p = 0.002) compared with small vessel disease. CONCLUSION: Increased LAVI was more prevalent in those who had cardiovascular risk factors, such as atrial fibrillation, hypertension, valvular heart disease and history of previous stroke. LAE influenced most patients in all subtypes of ischemic stroke but was most prevalent in the cardioembolic stroke subtype. Increased LAVI might be a risk factor of cerebral infarction, especially in patients with cardioembolic stroke subtype.

Comparison of the Clinical Course of Ischemic Stroke Depending on the Stroke Subtypes

BACKGROUND: There is still scarce information on the clinical course and prognosis in acute stroke patients with different etiologies. METHODS: We studied 464 patients with acute ischemic stroke within 24 hours of onset. Patients were assigned to 5 stroke subtypes based on the TOAST (Trial of Org 10172 in Acute Stroke Treatment) criteria with slight modification: small vessel occlusion (SVO, 30%), large artery atherosclerosis (LAA, 29%), cardioembolism (CE, 23%), stroke of two or more etiologies (STM, 12%), and stroke of undetermined etiology (SUD, 7%). The NIH Stroke Scale was used to assess the neurological status at day 0, 1, 3, 7, 14, and 28 after admission. The neurological deterioration and improvement at the examination period and the extent of recovery at one month were evaluated in different stroke subtypes. RESULTS: Most of the neurological deterioration occurred within 7 days after stroke, most frequently in LAA (30%), followed by STM (24%) and SVO (17%), and least frequently in CE (13%) and SUD (10%). In contrast, the temporal profile of neurological improvement was not different between subtypes. Patients with good recovery were most common in SVO (64%), whereas those with no recovery were most common in LAA (22%) and STM (28%). CONCLUSIONS: The clinical course was different according to stroke etiologies. Patients with LAA and STM experienced more frequent neurological deterioration and poorer recovery. SVO was associated with milder stroke and better recovery. CE and SUD caused severe neurological deficit, but lead to less frequent neurological deterioration and favorable recovery.

Mechanisms of Recurrence in Subtypes of Ischemic Stroke: A Hospital-based Follow-up Study

BACKGROUND: Great efforts have been devoted to developing a mechanism-oriented classification of ischemic stroke. Information on the subtype of recurrent stroke may tell us whether the classification using the index stroke mechanism is appropriate. Data on the mechanism of recurrence in each stroke subtype are lacking for Asian patients. METHODS: Using the clinical syndrome, diffusion-weighted imaging, and vascular studies, we divided the patients into five groups [large artery atherosclerosis (LAA), cardioembolism (CE), small artery disease (SAD), parent artery disease occluding the deep perforators (PAD), and no determined cause (NC)], and registered recurrent strokes for up to three years. The LAA patients were subdivided into two groups: intracranial (IC-LAA) and extracranial (EC-LAA) LAA. RESULTS: Seventy-six recurrent vascular events (73 strokes and 3 coronary heart diseases) were evaluated in 73 patients. The pattern of recurrent stroke differed for the IC-LAA and EC-LAA groups; unlike the patients with IC-LAA, recurrent strokes in EC-LAA were often unpredictable with respect to the site of recurrence and degree of pre-existing stenosis. None of the patients in the IC-LAA group recurred as EC-LAA, or vice versa. Patients with SAD and NC recurred most frequently as their index stroke subtype, but intracranial stenosis was often found at the time of recurrence. CONCLUSIONS: From a prognostic and therapeutic perspective, patients with atherosclerosis should be divided into IC-LAA and EC-LAA. In addition, intracranial atherosclerosis may be more important in the development of SAD and NC in Asians than in Westerners, due to the high prevalence of intracranial atherosclerosis.