Lisa Au

Risk factors for incident dementia after stroke and transient ischemic attack

We hypothesized that chronic brain changes are important substrates for incident dementia after stroke and transient ischemic attack (TIA).

Montreal Cognitive Assessment 5-Minute Protocol Is a Brief, Valid, Reliable, and Feasible Cognitive Screen for Telephone Administration

Background and Purpose— The National Institute of Neurological Disorders and Stroke-Canadian Stroke Network Vascular Cognitive Impairment Harmonization working group proposed a brief cognitive protocol for screening of vascular cognitive impairment. We investigated the validity, reliability, and feasibility of the Montreal Cognitive Assessment 5-minute protocol (MoCA 5-minute protocol) administered over the telephone. Methods— Four items examining attention, verbal learning and memory, executive functions/language, and orientation were extracted from the MoCA to form the MoCA 5-minute protocol. One hundred four patients with stroke or transient ischemic attack, including 53 with normal cognition (Clinical Dementia Rating, 0) and 51 with cognitive impairment (Clinical Dementia Rating, 0.5 or 1), were administered the MoCA in clinic and a month later, the MoCA 5-minute protocol over the telephone. Results— Administration of the MoCA 5-minute protocol took 5 minutes over the telephone. Total score of the MoCA 5-minute protocol correlated negatively with age (r=−0.36; P<0.001) and positively with years of education (r=0.41; P<0.001) but not with sex (&rgr;=0.03; P=0.773). Total scores of the MoCA and MoCA 5-minute protocol were highly correlated (r=0.87; P<0.001). The MoCA 5-minute protocol performed equally well as the MoCA in differentiating patients with cognitive impairment from those without (areas under receiver operating characteristics curve for MoCA 5-minute protocol, 0.78; MoCA=0.74; P>0.05 for difference; Cohen d for group difference, 0.80–1.13). It differentiated cognitively impaired patients with executive domain impairment from those without (areas under receiver operating characteristics curve, 0.89; P<0.001; Cohen d=1.7 for group difference). Thirty-day test–retest reliability was excellent (intraclass correlation coefficient, 0.89). Conclusions— The MoCA 5-minute protocol is a free, valid, and reliable cognitive screen for stroke and transient ischemic attack. It is brief and highly feasible for telephone administration.

Rituximab reduces attacks in Chinese patients with neuromyelitis optica spectrum disorders.

We evaluated the safety and efficacy of rituximab in seven Chinese patients with neuromyelitis optica (NMO) or neuromyelitis optica syndrome disorders (NMOSD) in a tertiary medical center in Hong Kong. After rituximab induction, five patients became relapse-free and two had 50% reduction of relapses over a median follow-up of 24 months. No further deterioration of functional status, measured by the Expanded Disability Status Scale, was observed in all patients. Infusions were well tolerated except in two patients who developed transient hypotension. Rituximab reduced clinical relapse and prevented neurological deterioration in a small cohort of Chinese patients with NMO or NMOSD.

Influence of Amyloid-β on Cognitive Decline After Stroke/Transient Ischemic Attack Three-Year Longitudinal Study

Background and Purpose— We hypothesized that comorbid amyloid-beta (A&bgr;) deposition played a key role in long-term cognitive decline in subjects with stroke/transient ischemic attack. Methods— We recruited 72 subjects with cognitive impairment after stroke/transient ischemic attack to receive Carbon-11-labeled Pittsburgh compound B positron emission tomography. We excluded subjects with known clinical Alzheimer’s disease. Those with and without Alzheimer’s disease–like A&bgr; deposition were classified as mixed vascular cognitive impairment (mVCI, n=14) and pure VCI (pVCI, n=58), respectively. We performed Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment to evaluate global cognition and cognitive domains (memory, visuospatial function, language, attention, and executive function) at 3 to 6 months (baseline) and annually for 3 years after the index event. We compared cognitive changes between mVCI and pVCI using linear mixed models and analysis of covariance adjusted for age and education. Results— Over 3 years, there were significant differences between mVCI and pVCI on change of MMSE score over time (group×time interaction, P=0.007). We observed a significant decline on MMSE score (P=0.020) in the mVCI group but not in the pVCI group (P=0.208). The annual rates of decline on MMSE (P=0.023) and Montreal Cognitive Assessment score (P=0.003) were greater in the mVCI group than in the pVCI group. Memory, visuospatial, and executive function domain scores on the Montreal Cognitive Assessment were related to A&bgr; deposition. Conclusions— Compared with subjects without Alzheimer’s disease–like A&bgr; deposition, those with A&bgr; deposition experienced a more severe and rapid cognitive decline over 3 years after stroke/transient ischemic attack. A&bgr; was associated with changes in multiple cognitive domains.

Evolution of intracranial atherosclerotic disease under modern medical therapy.

Understanding how symptomatic intracranial atherosclerotic disease (ICAD) evolves with current medical therapy may inform secondary stroke prevention.

Delayed-onset dementia after stroke or transient ischemic attack

Patients surviving stroke without immediate dementia are at high risk of delayed‐onset dementia. Mechanisms underlying delayed‐onset dementia are complex and may involve vascular and/or neurodegenerative diseases.

Pulse Pressure and Cognitive Decline in Stroke Patients With White Matter Changes

The authors hypothesized that both high and low pulse pressure (PP) may predict cognitive decline in stroke/transient ischemic attack (TIA) patients with white matter changes (WMCs). The authors prospectively followed up 406 ischemic stroke/TIA patients with confluent WMCs over 18 months. PP was measured at 3 to 6 months after stroke/TIA and categorized into four groups by quartile. Cognition was assessed 3 to 6 months and 15 to 18 months after stroke/TIA using the Clinical Dementia Rating and Mini‐Mental State Examination (MMSE). Logistic regression showed that patients in the first quartile of PP had a 5.9‐fold higher risk for developing cognitive decline than patients in the third quartile (odds ratio, 5.9; 95% confidence interval, 1.7–20.6), while patients in the fourth quartile had a 3.5‐fold higher risk for cognitive decline than those in the third quartile (odds ratio, 3.5; 95% confidence interval, 1.0–12.4). This U‐shaped relationship was also evident between PP and cognitive decline in MMSE, underlining the role of arterial stiffness and hypoperfusion in cognitive decline related to small vessel disease.

Neuropsychiatric Symptom Clusters in Stroke and Transient Ischemic Attack by Cognitive Status and Stroke Subtype: Frequency and Relationships with Vascular Lesions, Brain Atrophy and Amyloid.

Background The objectives of this study are 1) to examine the frequencies of neuropsychiatric symptom clusters in patients with stroke or transient ischemic attack (TIA) by cognitive level and stroke subtype; and 2) to evaluate effect of demographic, clinical, and neuroimaging measures of chronic brain changes and amyloid upon neuropsychiatric symptom clusters. Methods Hospital-based, cross-sectional study. 518 patients were administered the Neuropsychiatric Inventory (NPI) 3–6 months post index admission. NPI symptoms were classified into four symptom clusters (Behavioral Problems, Psychosis, Mood Disturbance & Euphoria) derived from a confirmatory factor analysis of the 12 NPI items. Multivariable logistic regression was used to determine independent associations between demographic, clinical and neuroimaging measures of chronic brain changes (white matter changes, old infarcts, whole brain atrophy, medial temporal lobe atrophy [MTLA] and frontal lobe atrophy [FLA]) with the presence of NPI symptoms and all symptom clusters except euphoria. 11C-Pittsburg Compound B Positron Emission Tomography (11C-PiB PET) was performed in 24 patients to measure amyloid retention for Alzheimer’s Disease (AD) pathology. Results 50.6% of the whole sample, including 28.7% cognitively normal and 66.7% of patients with mild cognitive symptoms, had ≥1 NPI symptoms. Frequencies of symptom clusters were largely similar between stroke subtypes. Compared to patients with cardioembolic stroke and intracranial haemorrhage, those with TIA had less frequent mood disturbance. Stroke severity at admission and MTLA were the most robust correlates of symptoms. FLA was associated with behavioral problems cluster only. Frequency of symptom clusters did not differ between patients with and without significant amyloid retention. Conclusion Frequency of neuropsychiatric symptoms increased with level of cognitive impairment but was largely similar between stroke subtypes. Stroke severity and MTLA were associated with neuropsychiatric symptoms. AD pathology appeared to be unrelated to neuropsychiatric manifestations but further studies with larger sample size are required to substantiate this finding.

Cerebral Microbleeds and Cognitive Function in Ischemic Stroke or Transient Ischemic Attack Patients

Background: We explored the association between cerebral microbleeds (CMBs) and cognitive impairment in patients with ischemic stroke/transient ischemic attack (TIA). Methods: A total of 488 ischemic stroke/TIA patients received magnetic resonance imaging. Montreal Cognitive Assessment (MoCA) was used to evaluate global cognitive function and cognitive domains. The association of CMB quantity with cognitive function and the impact of CMB locations (strictly lobar, strictly deep, and mixed regions) on cognitive impairment were examined in regression models with adjustments for confounders. Results: A total of 113 subjects (23.2%) had ≥1 CMB. Strictly lobar, strictly deep, and mixed CMBs were identified in 36, 40, and 37 patients, respectively. The presence of ≥5 CMBs or strictly deep CMBs was associated with the MoCA total score (p = 0.007 and 0.020, respectively). Of all MoCA domains tested, a lower score in the attention domain was related to the presence of ≥5 CMBs (p = 0.014) and strictly deep CMBs (p = 0.028). Conclusion: CMBs were associated with cognitive dysfunction in stroke/TIA patients, especially in the attention domain. This association was mainly driven by CMBs in the deep region, underlining the role of hypertensive microangiopathy in stroke-related cognitive impairment.

Converting MMSE to MoCA and MoCA 5-minute protocol in an educationally heterogeneous sample with stroke or transient ischemic attack

The Montreal Cognitive Assessment (MoCA) is psychometrically superior over the Mini‐mental State Examination (MMSE) for cognitive screening in stroke or transient ischemic attack (TIA). It is free for clinical and research use. The objective of this study is to convert scores from the MMSE to MoCA and MoCA‐5‐minute protocol (MoCA‐5 min) and to examine the ability of the converted scores in detecting cognitive impairment after stroke or TIA.