The validity of the Montreal Cognitive Assessment (MoCA) as a screen for mild cognitive impairment (MCI) and dementia was evaluated in African Americans attending an urban outpatient memory disorders clinic. Eighty one patients ≥50 years old were administered the MoCA and neuropsychological tests. Clinicians, blinded to the MoCA scores, reviewed the neuropsychological findings and reports of instrumental activities of daily living and they assigned a diagnosis of normal cognition (NC; N = 16), MCI (N = 38), or dementia (N = 27). The MoCA scores of the 3 groups were significantly different (NC > MCI > dementia). Using cutoff scores of ≤24 points for MCI and ≤22 points for dementia, the MoCA had .95 sensitivity and .63 specificity for MCI and .96 sensitivity and .88 specificity for dementia. The MoCA is a valid and cost-effective screen for cognitive impairment in African Americans but with a higher likelihood of falsely classifying persons with NC as having MCI.

This study investigated the relationship between the vascular comorbidities (VCs) of hypertension and hypercholesterolemia and the cognitive phenotype of Alzheimer disease (AD). Seventy-four AD patients underwent objective measurement of blood pressure and serum cholesterol levels, and they received a detailed neuropsychologic evaluation examining attention, memory, language, visuomotor/visuospatial skills, and executive functioning. Multiple regression analyses controlling for demographic variables, overall cognitive status, and the presence of diabetes/cardiac disease indicated that an increase in the number of VCs, but not their severity, was associated with poorer verbal and visual recall, visuoconstructive and spatial analysis, verbal reasoning, and set shifting. The findings demonstrate that VCs are associated with specific aspects of cognitive functioning in AD patients. The mechanisms likely involve the effects of VCs on cerebrovascular disease including white matter disruption. The results highlight the importance of controlling these risk factors in patients who carry the diagnosis of AD.

The authors examined the relationship between hypertension and cognitive performance in 34 African-American patients with probable Alzheimer disease. Multiple regression analyses indicated that hypertension was associated with poorer overall performance on the Mattis Dementia Rating Scale, particularly the Initiation/Perseveration and Conceptualization subscales, after controlling for gender, age, and education. The findings suggest that African-American patients with hypertension exhibit greater cognitive impairment, possibly reflecting executive dysfunction.

Recent evidence suggests that patients with Alzheimer's disease (AD) and vascular comorbidities (VC) perform worse across measures of verbal reasoning and abstraction when compared to patients with AD alone. We performed a qualitative error analysis of WAIS-III Similarities zeropoint responses in 45 AD patients with varying numbers of VC including diabetes, hypertension and hypercholesterolemia. Errors were scored in set if the answer was vaguely related to the word pair (e.g., doglion: 'they can be trained') and out of set if the response was unrelated ('a lion can eat a dog'). AD patients with 2-3 VC did not differ on Similarities total score or qualitative errors from AD patients with 0-1 VC. When analyzing the group as a whole, we found that increasing numbers of VC were significantly associated with increasing out of set errors and decreasing in set errors in AD. Of the vascular diseases investigated, it was only the severity of diastolic blood pressure that significantly correlated with out of set responses. Understanding the contribution of VC to patterns of impairment in AD may provide support for directed patient and caregiver education concerning the presentation of a more severe pattern of cognitive impairment in affected individuals.