Montreal Cognitive Assessment and Mini-Mental State Examination are both valid cognitive tools in stroke.

OBJECTIVE: To determine the validity of the Montreal Cognitive Assessment (MoCA) and the Mini-Mental State Examination (MMSE) as screening tools for cognitive impairment after stroke. MATERIALS AND METHODS: Cognitive assessments were administered over 2 sessions (1 week apart) at 3 months post-stroke. Scores on the MoCA and MMSE were evaluated against a diagnosis of cognitive impairment derived from a comprehensive neuropsychological battery (the criterion standard). RESULTS: Sixty patients participated in the study [mean age 72.1 years (SD = 13.9), mean education 10.5 years (SD = 3.9), median acute NIHSS score 5 (IQR 3-7)]. The MoCA yielded lower scores (median = 21, IQR = 17-24; mean = 20.0, SD = 5.4) than the MMSE (median = 26, IQR = 22-27; mean = 24.2, SD = 4.5). MMSE data were more skewed towards ceiling than MoCA data (skewness = -1.09 vs -0.73). Area under the receiver operator curve was higher for MoCA than for MMSE (0.87 vs 0.84), although this difference was not significant (χ(2) = 0.48, P = 0.49). At their optimal cut-offs, the MoCA had better sensitivity than the MMSE (0.92 vs 0.82) but poorer specificity (0.67 vs 0.76). CONCLUSIONS: The MoCA is a valid screening tool for post-stroke cognitive impairment; it is more sensitive but less specific than the MMSE. Contrary to the prevailing view, the MMSE also exhibited acceptable validity in this setting.

Little evidence for different phenomenology in poststroke depression.

OBJECTIVE: It remains unclear whether mood depressive disorders after stroke have a distinct phenomenology. We evaluated the symptom profile of poststroke depression (PSD) and assessed whether somatic symptoms were reported disproportionately by stroke patients. METHOD: The sample was 149 stroke patients at 18 months poststroke and 745 age- and sex-matched general population controls. A comprehensive psychiatric interview was undertaken and depression was diagnosed according to DSM-III-R criteria. RESULTS: Depressed controls reported more 'inability to feel' (P = 0.002) and 'disturbed sleep' (P = 0.008) than depressed stroke patients. Factor analysis of the 10 depressive symptoms identified two main factors, which appeared to represent somatic and psychological symptoms. There was no difference in scores on these two factors between stroke patients and controls. CONCLUSION: Phenomenology of depression at 18 months poststroke is broadly similar but not the same as that described by controls. Somatic symptoms of depression were not over-reported by stroke patients.

Repetition priming and hyperpriming in semantic dementia.

Evidence from neurologically normal subjects suggests that repetition priming (RP) is independent of semantic processing. Therefore, we may expect patients with a selective deficit to conceptual knowledge to exhibit RP for words regardless of the integrity of their semantic representations. We tested six patients with semantic dementia (SD) on a lexical decision task that incorporated four different lags between first (baseline) and second (primed) presentation of repeated words. The patients exhibited significant RP that was greater for words that were categorised as semantically 'degraded' than for words categorised as 'known.' This RP advantage for semantically degraded words declined as lag increased. The patients also demonstrated hyperpriming, and a significant correlation was identified between baseline response time and RP in SD but not in controls. These findings indicate that level of semantic knowledge about a word influences both baseline lexical decision performance and RP of that word. The observed hyperpriming can be parsimoniously explained by a cognitive slowing account.