2007). During this test, individuals are asked

to read aloud a list of 50 irregularly pronounced words. Estimated IQ based on the WTAR was used in the current analyses to control for the effects of premorbid intelligence on neurocognitive function. Premorbid IQ taps into innate intelligence and is a sensitive marker of cognitive reserve (Alexander et al. 1997). Demographic and medical characteristics The patient’s medical history and currently prescribed medications were self-reported during two interviews and confirmed by medical records when possible. Medications were categorized by class and those identified as cardiovascular medications were reviewed and confirmed by a clinical Inhibitors,research,lifescience,medical Inhibitors,research,lifescience,medical cardiologist. Statistical analyses All RBANS GABA Receptor inhibitor composite scores were converted to standard scores (i.e., a distribution with a mean of 100 and a standard deviation of 15) adjusted for age using normative values. Normative data for the RBANS composite was used in order to facilitate clinical interpretation of cognitive status in the current sample. TMT A and B scores were also converted to standard scores for similar reasoning. A composite of gray matter volume and cortical thickness of each brain region including frontal, temporal, parietal,

Inhibitors,research,lifescience,medical and occipital lobes were calculated using the organization schema as described in Desikan et al. (2006). Total brain volume (TBV) and thickness consisted of the sum and average of the frontal, temporal, parietal, and occipital lobe gray

matter, respectively. All analyses Inhibitors,research,lifescience,medical examining brain volume and thickness were adjusted for intracranial volume. Lastly, a total brain perfusion composite was also computed that consisted of the mean perfusion to the left and Inhibitors,research,lifescience,medical right hemispheres of the frontal, temporal, parietal, and occipital lobe gray matter. For analyses examining regional perfusion, the average of the left and right hemispheres for each lobe was computed. One participant exhibited missing data for occipital lobe perfusion and total brain perfusion for this participant consisted of the average of the remaining lobes. There was also one case with missing data on TMT B and this case was excluded from analyses examining this cognitive test as the dependent variable. Separate multivariable hierarchical regression analyses were performed for the MMSE, each RBANS composite, aminophylline TMT A, and TMT B. For each model, demographic and medical characteristics were entered in block 1 that included: Age, sex (−1 = male; 1 = female), premorbid intelligence (as estimated by the WTAR), cardiac index, heart rate, diagnostic history of hypertension, diabetes, and atrial fibrillation (1 = positive history; 0 = negative history). Total brain cerebral perfusion was then entered into block two of each model to determine its incremental predictive validity on cognitive function.