The purpose of this study was to construct a Swedish version of the National Adult Reading Test (NART-SWE), a test for assessment of premorbid IQ, and to investigate its validity and reliability on healthy controls and patients with mild Alzheimer's disease. As Swedish pronunciation rules are fixed, NART-SWE was constructed using loan words. NART-SWE has satisfactory psychometric properties: Inter-rater and retest reliability as well as internal consistency are very high. The NART-SWE demonstrates face validity. In addition, high correlation with IQ was obtained. A significant model emerged when using NART-SWE to predict IQ. Furthermore, no significant differences were observed when comparing performance for healthy controls' with that of patients with Alzheimer's disease on NART-SWE. It does appear that reading of irregular words is intact in mild Alzheimer's disease.

Background: The concept of the cognitive reserve (CR) posits that factors such as education enable compensation for the effect of brain pathology. Consequently, pathology should be more pronounced in individuals with higher CR before becoming clinically apparent. Biomarkers such as total tau (t-tau) and β-amyloid 42 (Aβ42) may be surrogates for pathology in relation to CR in patients with neurodegenerative disease. Objective: To examine the applicability of biomarkers as surrogates for pathology in relation to the CR in patients with mild cognitive impairment (MCI) either converting to dementia or remaining stable at follow-up. Method: Comparisons of baseline t-tau, Aβ42, educational years and global cognition for MCI patients either converting to dementia (n = 57) or remaining stable (n = 91) were made. Patients converting to dementia were grouped on the basis of educational level and compared considering biomarkers and neuropsychological tests. Results: Stable MCI patients were better educated, performed better cognitively, had higher Aβ42 levels and lower levels of t-tau. Converting MCI patients with higher education had lower levels of Aβ42 and performed equally in neuropsychological tests compared to those with lower education. Conclusion: Our results suggest that highly educated MCI patients subsequently converting to dementia display more amyloid pathology.

The concepts of brain and cognitive reserve stem from the observation that premorbid factors (e.g., education) result in variation in the response to brain pathology. Potential early influence of reserve on pathology, as assessed using the cerebrospinal fluid biomarkers total tau (t-tau) and amyloid-beta42, and cognition was explored in mild cognitive impairment (MCI) patients who remained stable over a two-year period. A total of 102 patients with stable MCI grouped on the basis of educational level were compared with regard to biomarker concentrations and cognitive performance. Stable MCI patients with higher education had lower concentrations of t-tau as compared to those with lower education. Also, educational level predicted a significant proportion of the total variance in t-tau concentrations. Our results suggest that higher education may offer protection against tauopathy.

The concept of the cognitive reserve (CR) hypothesizes that premorbid factors such as education enable compensation for the manifestation of brain pathology. Accordingly, pathology should be more prominent in individuals with higher CR before becoming clinically apparent. Previously, we found that patients subsequently converting to dementia with higher CR had lower concentrations of amyloid beta 42 (abeta42) as compared to patients with lower CR. However, the interaction between time, biomarkers, neuropsychological performance and CR is yet to be established. Objective: To study the relation between biomarkers, neuropsychological performance and CR longitudinally. Method: A mixed between-within subject analysis of variance was performed for longitudinal analysis. Paired t tests were used for within group comparisons. Results: Patients with higher CR (n = 15) had significantly lower concentrations of abeta42 at both time points compared to those with medium (n = 23) and lower CR (n = 28). Also, abeta42 concentrations decreased significantly from baseline to follow-up in patients with higher and medium CR. Groups performed comparably on neuropsychological tests. Conclusion: This study provides further support for the applicability of abeta42 as a substitute for pathology in relation to CR. Also, abeta42 reflects the disease progression in patients with higher and medium CR.