Clinical and radiological determinants of transient symptoms associated with infarction (TSI).

BACKGROUND: The definition of transient ischemic attack was traditionally based on clinical features only. The wide use of magnetic resonance imaging (MRI) led to the definition of a new entity - transient symptoms associated with infarction (TSI). It is unclear why patients with similar radiological infarctions may have different clinical manifestation - ranging from complete symptoms resolution to major neurological sequelae. We sought to determine which factors differentiate acute diffuse weighted imaging (DWI) lesion presentation - stroke versus TSI. METHODS: 282 Participants, recruited for the Tel-Aviv Brain Acute Stroke Cohort study (TABASCO), were enrolled consecutively. Participants underwent extensive cognitive evaluation, wide laboratory tests and brain MRI scans evaluated for cerebral small vessel disease (SVD) biomarkers, according to the STRIVE protocol. Demographic and clinical characteristics were also examined. RESULTS: A total of 239 patients had stroke and 43 patients had TSI. TSI patients had smaller average lesion volume (0.77 cm3 versus 2.64 cm3, p = 0.002). Lesion location did not differentiate TSI and stroke. Stroke patients had elevated inflammatory markers, unrelated to lesion size (CRP 4.2 mg/L versus 1.7 mg/L, p = 0.011). TSI patients had better global cognitive score and MoCA score at admission and 24 months following the index event (p < 0.001). TSI patients also had better Berg balance score (p = 0.004). No significant association was found with MRI SVD markers. CONCLUSIONS: Lesion size, but not location, differentiates TSI and stroke, especially at a cutoff value of 10 cm3. Elevated inflammatory response was linked to worse course independently of lesion volume. Cognitive and high function tests are associated to the clinical phenotype of ischemic lesion and may be a marker of brain reserve and compensatory abilities. SVD markers do not differ between TSI and stroke patients and probably do not fully capture the extent of brain vascular pathology and reserve.

High hair cortisol concentrations predict worse cognitive outcome after stroke: Results from the TABASCO prospective cohort study.

BACKGROUND AND PURPOSE: The role of stress-related endocrine dysregulation in the development of cognitive changes following a stroke needs further elucidation. We explored this issue in a longitudinal study on stroke survivors using hair cortisol concentrations (HCC), a measure of integrated long-term cortisol levels. METHODS: Participants were consecutive cognitively intact first-ever mild-moderate ischemic stroke/transient ischemic attack (TIA) survivors from the Tel Aviv Brain Acute Stroke Cohort (TABASCO) study. They underwent 3T magnetic resonance imaging (MRI) scanning and were cognitively assessed at admission, and at 6, 12 and 24 months post-stroke. Scalp hair samples were obtained during the initial hospitalization. RESULTS: Full data on baseline HCC, MRI scans and 2 years neuropsychological assessments were available for 65 patients. Higher HCC were significantly associated with a larger lesion volume and with worse cognitive results 6, 12 and 24 months post-stroke on most of the neurocognitive tests. 15.4% of the participants went on to develop clinically significant cognitive decline in the follow-up period, and higher HCC at baseline were found to be a significant risk factor for this decline, after adjustment for age, gender, body mass index and APOE e4 carrier status (HR=6.553, p=0.038). CONCLUSIONS: Our findings suggest that individuals with higher HCC, which probably reflect higher long-term cortisol release, are prone to develop cognitive decline following an acute stroke or TIA.

Intensified vmPFC surveillance over PTSS under perturbed microRNA-608/AChE interaction.

Trauma causes variable risk of posttraumatic stress symptoms (PTSS) owing to yet-unknown genome-neuronal interactions. Here, we report co-intensified amygdala and ventromedial prefrontal cortex (vmPFC) emotional responses that may overcome PTSS in individuals with the single-nucleotide polymorphism (SNP) rs17228616 in the acetylcholinesterase (AChE) gene. We have recently shown that in individuals with the minor rs17228616 allele, this SNP interrupts AChE suppression by microRNA (miRNA)-608, leading to cortical elevation of brain AChE and reduced cortisol and the miRNA-608 target GABAergic modulator CDC42, all stress-associated. To examine whether this SNP has effects on PTSS and threat-related brain circuits, we exposed 76 healthy Israel Defense Forces soldiers who experienced chronic military stress to a functional magnetic resonance imaging task of emotional and neutral visual stimuli. Minor allele individuals predictably reacted to emotional stimuli by hyperactivated amygdala, a hallmark of PTSS and a predisposing factor of posttraumatic stress disorder (PTSD). Despite this, minor allele individuals showed no difference in PTSS levels. Mediation analyses indicated that the potentiated amygdala reactivity in minor allele soldiers promoted enhanced vmPFC recruitment that was associated with their limited PTSS. Furthermore, we found interrelated expression levels of several miRNA-608 targets including CD44, CDC42 and interleukin 6 in human amygdala samples (N=7). Our findings suggest that miRNA-608/AChE interaction is involved in the threat circuitry and PTSS and support a model where greater vmPFC regulatory activity compensates for amygdala hyperactivation in minor allele individuals to neutralize their PTSS susceptibility.