Transient Ischemic Attack Subjects Research Articles

Abstract WMP120: Vascular Risk Factor Reduction Is Associated With Corneal Nerve Regeneration In Patients With Tia And Ischemic Stroke

Background and Purpose: Vascular risk factors are associated with transient ischemic attack (TIA), acute ischemic stroke (AIS) and corneal nerve damage. We have assessed if an improvement in vascular risk factors in patients with TIA and AIS is associated with corneal nerve regeneration. Methods: Patients with TIA or AIS and control subjects underwent assessment of clinical and vascular risk factors and corneal confocal microscopy (CCM) at baseline and 1-year follow up. Results: Eighty-one patients with TIA (n=28), AIS (n=53) and control subjects (n=56) were studied. Systolic blood pressure (SBP)( P =0.000), diastolic blood pressure (DBP) ( P =0.000) and HbA1 c (P=0.000) were significantly higher and HDL ( P =0.000), corneal nerve fiber length (CNFL) (P=0.000), corneal nerve fiber density (CNFD) (P=0.000) and corneal nerve branch density (CNBD) (P=0.003) were significantly lower in patients with TIA/AIS compared to controls. At follow up, there was a significant decrease in triglycerides (-0.37 mmol/l, P=0.005), total cholesterol (-1.12 mmol/l, P=0.000); LDL-cholesterol (-1.08 mmol/l, P=0.000), SBP (-24.76 mmHg, P=0.000), DBP (-14.24 mmHg, P=0.000) and HbA1 c (-0.50 mmol/l, P=0.027) and an increase in HDL (0.10 mmol/l, P=0.010), CNFL (1.48 mm/mm 2 , P=0.018), CNFD (1.66 no./mm 2 , P=0.024), and CNBD (26.90 no./mm 2 , P=0.000). The improvement in lipids and blood pressure was associated with an increase in corneal nerve parameters ( P <0.05). Conclusions: An improvement in vascular risk factors in patients with TIA or AIS is associated with corneal nerve regeneration. CCM could be used to assess the effectiveness of risk factor reduction in patients with TIA or AIS.

White matter tract microstructure and cognitive performance after transient ischemic attack.

Background and purposePatients with transient ischemic attack (TIA) show evidence of cognitive impairment but the reason is not clear. Measurement of microstructural changes in white matter (WM) using diffusion tensor imaging (DTI) may be a useful outcome measure. We report WM changes using DTI and the relationship with neuropsychological performance in a cohort of transient ischemic attack (TIA) and non-TIA subjects.MethodsNinety-five TIA subjects and 51 non-TIA subjects were assessed using DTI and neuropsychological batteries. Fractional anisotropy (FA) and mean diffusivity (MD) maps were generated and measurements were collected from WM tracts. Adjusted mixed effects regression modelled the relationship between groups and DTI metrics.ResultsTransient ischemic attack subjects had a mean age of 67.9 ± 9.4 years, and non-TIA subjects had a mean age 64.9 ± 9.9 years. The TIA group exhibited higher MD values in the fornix (0.36 units, P < 0.001) and lower FA in the superior longitudinal fasciculus (SLF) (-0.29 units, P = 0.001), genu (-0.22 units, P = 0.016), and uncinate fasciculus (UF) (-0.26 units, P = 0.004). Compared to non-TIA subjects, subjects with TIA scored lower on the Addenbrooke’s Cognitive Assessment-Revised (median score 95 vs 91, P = 0.01) but showed no differences in scores on the Montreal Cognitive Assessment (median 27 vs 26) or the Mini-Mental State Examination (median 30). TIA subjects had lower scores in memory (median 44 vs 52, P < 0.01) and processing speed (median 45 vs 62, P < 0.01) but not executive function, when compared to non-TIA subjects. Lower FA and higher MD in the fornix, SLF, and UF were associated with poorer performance on tests of visual memory and executive function but not verbal memory. Lower FA in the UF and fornix were related to higher timed scores on the TMT-B (P < 0.01), and higher SLF MD was related to higher scores on TMT-B (P < 0.01), confirming worse executive performance in the TIA group.ConclusionsDTI scans may be useful for detecting microstructural disease in TIA subjects before cognitive symptoms develop. DTI parameters, white matter hyperintensities, and vascular risk factors underly some of the altered neuropsychological measures in TIA subjects.

Depression and Antidepressant Use After Stroke and Transient Ischemic Attack

Patients with stroke and transient ischemic attack (TIA) often have comparable comorbidities, but it is unclear whether they have similar rates of depression or antidepressant use. This study was a secondary analysis of a prospective cohort registry that enrolled subjects from 2006 to 2008 in the United States. Depression (defined by the Patient Health Questionnaire-8 score ≥ 10) and medication use were prospectively assessed 3 and 12 months after hospitalization in 1450 subjects with ischemic stroke and 397 subjects with TIA. The proportional frequency of depression after stroke and TIA was similar at 3 months (17.9% versus 14.3%, P=0.09) and at 12 months (16.4% versus 12.8%, P=0.08). The rates of newly identified depression between 3 and 12 months were also similar (8.7% versus 6.2%, P=0.12). Persistent depression (defined as Patient Health Questionnaire-8 score ≥ 10 at both 3 and 12 months) was present in 134 (9.2%) of those with stroke and in 30 (7.6%) of those with TIA. Younger age, greater stroke-related disability, and inability to work at 3 months were associated with persistent depression in subjects with stroke. Among subjects with persistent depression, 67.9% of those with stroke and 70.0% of those with TIA were not using antidepressants at either time point (P=0.920). Stroke and TIA subjects had a similar frequency of depression at 3 and 12 months after hospitalization and similar rates of newly identified depression between 3 and 12 months. A high proportion of those with persistent depression was untreated.

Ischemic Transient Neurological Events Identified by Immune Response to Cerebral Ischemia

Deciphering whether a transient neurological event (TNE) is of ischemic or nonischemic etiology can be challenging. Ischemia of cerebral tissue elicits an immune response in stroke and transient ischemic attack (TIA). This response, as detected by RNA expressed in immune cells, could potentially distinguish ischemic from nonischemic TNE. Analysis of 208 TIAs, ischemic strokes, controls, and TNE was performed. RNA from blood was processed on microarrays. TIAs (n=26) and ischemic strokes (n=94) were compared with controls (n=44) to identify differentially expressed genes (false discovery rate <0.05, fold change ≥1.2). Genes common to TIA and stroke were used predict ischemia in TIA diffusion-weighted imaging-positive/minor stroke (n=17), nonischemic TNE (n=13), and TNE of unclear etiology (n=14). Seventy-four genes expressed in TIA were common to those in ischemic stroke. Functional pathways common to TIA and stroke related to activation of innate and adaptive immune systems, involving granulocytes and B cells. A prediction model using 26 of the 74 ischemia genes distinguished TIA and stroke subjects from control subjects with 89% sensitivity and specificity. In the validation cohort, 17 of 17 TIA diffusion-weighted imaging-positive/minor strokes were predicted to be ischemic, and 10 of 13 nonischemic TNE were predicted to be nonischemic. In TNE of unclear etiology, 71% were predicted to be ischemic. These subjects had higher ABCD(2) scores. A common molecular response to ischemia in TIA and stroke was identified, relating to activation of innate and adaptive immune systems. TNE of ischemic etiology was identified based on gene profiles that may be of clinical use once validated.

Prolonged Rhythm Monitoring for the Detection of Occult Paroxysmal Atrial Fibrillation in Ischemic Stroke of Unknown Cause

Atrial fibrillation (AF), commonly encountered in patients with ischemic stroke and transient ischemic attack (TIA), confers a 5-fold increased risk of ischemic stroke.1,2 AF-related strokes are associated with an ≈50% increased risk of disability and 60% increased risk of death at 3 months compared with strokes of other etiologies.3 Paroxysmal AF (PAF), a self-terminating recurrent form of cardiac arrhythmia that comprises between 25% and 62% of AF cases, may present as a brief single episode of arrhythmia or as clusters of abnormal rhythm of variable duration, sometimes evolving into a more persistent or permanent form.4 The self-terminating nature of PAF may lead to its underdiagnosis and consequent use of less effective treatment strategies (aspirin instead of oral anticoagulation) in poststroke patients. To address the underdiagnosis of PAF in patients with ischemic stroke and TIAs, several treatment guidelines have singled out the identification of PAF as an important goal after a stroke/TIA.5–8 The diagnosis of PAF, however, poses a challenge. Several features of AF (such as its brief duration, episodic frequency, and asymptomatic presentations) make its detection difficult and elusive to bedside screening measures, such as pulse monitoring and routine ECGs. To date, several studies have explored the use of prolonged noninvasive and invasive cardiac monitoring devices to identify AF but with variable success. After detection of AF, a cardioembolic mechanism is often inferred and anticoagulation occasionally prescribed for secondary stroke prevention. The routine use of cardiac monitoring to identify patients with PAF who will benefit from anticoagulation has been reported to be cost-effective.9 In this review, we provide an overview of the different methods of cardiac monitoring, summarize studies that investigated the incidence of PAF after stroke, and highlight gaps in our understanding of the pathogenic and prognostic significance of AF …

Diminished global fibrinolytic capacity in patients with mitral valve prolapse is associated with transient ischemic attacks.

Although mitral valve prolapse (MVP) has shown to be associated with thromboembolic complications, the cause of thromboembolic events in those patients is still unknown. The purpose of this study was to evaluate the fibrinolytic activity in MVP patients. The study included 35 consecutive patients (25 women, mean age 25+/-11 years) with echocardiographically documented MVP and 25 age- and sex-matched subjects as a control group. Four of MVP patients have a history of transient ischemic attack (TIA). Global fibrinolytic capacity (GFC), a new technique that examines the effectiveness of the entire fibrinolytic system, was measured. Global fibrinolytic capacity was found to be nonsignificantly increased in MVP patients (3.14+/-1.42 microg/mL) compared to those in control subjects (2.36+/-1.33 microg/mL) (p>0.05). However, in four of these MVP patients who had a history of transient ischemic attack, the GFC level was significantly lower than in patients who have no history of transient ischemic attack (1.67+/-0.6 microg/mL vs 3.27+/-1.46 (microg/mL, p=0.003). Furthermore, the GFC levels of these four patients were less than those of controls (p=0.04). These results showed that global fibrinolytic activity was similar in MVP patients without a history of TIA and control subjects. However, MVP patients with a history of TIA had significantly decreased global fibrinolytic activity compared to controls and as well as MVP patients without a history of TIA.

Sleep apnea in acute cerebrovascular diseases: final report on 128 patients.

Although obstructive sleep apnea (OSA) appears to be a cardiovascular risk factor, its frequency in patients with transient ischemic attack (TIA) and stroke remains poorly known. We prospectively studied 128 patients (mean +/- SD age = 59 +/- 15 years) with stroke (n = 75) or TIA (n = 53). Assessment included body mass index (BMI); history of snoring and daytime sleepiness; cardiovascular risk factors and diseases; and severity of stroke (Scandinavian Stroke Scale = SSS). Polysomnography (PSG) was obtained in 80 subjects (group 1), a mean of 9 days (range, 1-71 days) after TIA or stroke. In 48 subjects (group 2), PSG was not available, refused, or inadequate. Groups 1 and 2 were similar with the exception of gender distribution. Clinical and PSG data were compared to those of 25 healthy controls matched for age, gender, and BMI. An apnea-hypopnea index (AHI) > 10 was found in 62.5% of subjects and 12.5% of controls. Between patients and controls there was a significant difference in AHI (mean [range]: 28 (0-140) vs 5 (0-24), p < 0.001), maximal apnea duration (mean + SD: 37 +/- 23 vs 23 +/- 13 seconds, p = 0.009), and minimal oxygen saturation (mean + SD: 82 +/- 10% vs 90 +/- 5%, p < 0.001). Conversely, frequency and severity of OSA were similar in stroke and TIA subjects. Multiple regression analysis identified age, BMI, diabetes, and SSS as independent predictors of AHI. Sleep apnea has a high frequency in patients with TIA and stroke, particularly in older patients with high BMI, diabetes, and severe stroke. These results may have implications for prevention, acute treatment, and rehabilitation of patients with acute cerebrovascular diseases.