Detecting cognitive impairment in individuals at risk for cardiovascular disease: the "Clock-in-the-Box" screening test.

OBJECTIVE: The purpose of this study was to evaluate the performance on the Clock-in-the-Box (CIB), a screening measure for cognitive function, relative to neuropsychological testing in an older population with cardiovascular risk. METHODS: A prospective cohort of older patients (>50 years) with cardiovascular risk was recruited to perform the CIB and complete a brief neuropsychological battery consisting of Trailmaking tests, the Hopkins Verbal Learning Test (HVLT), and fluency tasks. Performance on the CIB was scored according to standard criteria (range 0-8, 0-worst). The performance on the total CIB, working memory subscale (CIB-WM), and planning/organization (COB-PO) was compared to neuropsychological measures. RESULTS: The cohort (n = 127) was older (age 67 ± 7 years) and diverse with 33% female (n = 42) and 42% non-white race (n = 53). Cardiac risk factors were prevalent: hypertension (83%), hyperlipidemia (74%), overweight (84%), diabetes (48%), prior cardiac disease (39%), and smoking (11%). The CIB (mean 6.5 ± 1.3) took 84 ± 21 s on average to complete and had good inter-rater reliability (κ = 0.809, p < 0.01). The CIB-WM subscale was significantly correlated with performance on Trailmaking B and HVLT learning, recall, and recognition. The CIB-PO subscale was significantly associated with semantic and phonemic fluency, Trailmaking B, and HVLT learning and recall. In regression modeling, CIB-WM significantly predicted performance on HVLT learning, recall, and retention. CIB-PO subscale predicted performance on Trailmaking B, HVLT learning, and HVLT recall. CONCLUSIONS: The CIB is a brief cognitive screening instrument with good reliability and predictive validity in a CV risk population. The CIB-WM and CIB-PO subscales could provide utility for clinicians.

Variation in blood pressure is associated with white matter microstructure but not cognition in African Americans.

Although hypertension is a major risk factor for cerebrovascular disease (CVD) and is highly prevalent in African Americans, little is known about how blood pressure (BP) affects brain-behavior relationships in this population. In predominantly Caucasian populations, high BP is associated with alterations in frontal-subcortical white matter and in executive functioning aspects of cognition. We investigated associations among BP, brain structure, and neuropsychological functioning in 52 middle-older-age African Americans without diagnosed history of CVD. All participants underwent diffusion tensor imaging for examination of white matter integrity, indexed by fractional anisotropy (FA). Three regions of interest were derived in the anterior (genu) and posterior (splenium) corpus callosum and across the whole brain. A brief neuropsychological battery was administered from which composite scores of executive function and memory were derived. Blood pressure was characterized by mean arterial blood pressure (MABP). When controlling for age, higher MABP was associated with lower FA in the genu, and there was a trend for this same relationship with regard to whole-brain FA. When the sample was broken into groups on the basis of treatment for BP regulation (medicated vs. nonmedicated), MABP was related to genu and whole-brain FA only in the nonmedicated group. Neither MABP nor FA was significantly related to either neuropsychological composite score regardless of medication use. These data provide important evidence that variation in BP may contribute to significant alterations in specific neural regions of white matter in nonmedicated individuals without symptoms of overt CVD.