Abstract. While APOE ε4 is the major genetic risk factor for Alzheimer's disease (AD), amyloid dysmetabolism is an initial or early event predicting clinical disease and is an important focus for secondary intervention trials. To improve identification of cases with increased AD risk, we evaluated recruitment procedures using pathological CSF concentrations of A␤ 42 (pA␤) and APOE ε4 as risk markers in a multi-center study in Norway. In total, 490 subjects aged 40-80 y were included after response to advertisements and media coverage or memory clinics referrals. Controls (n = 164) were classified as normal controls without first-degree relatives with dementia (NC), normal controls with first-degree relatives with dementia (NCFD), or controls scoring below norms on cognitive screening. Patients (n = 301) were classified as subjective cognitive decline or * Correspondence to: Lene Pålhaugen, P.B. 1000, N-1478 Lørenskog, Norway. Tel.: +47 95832775; E-mail: lene. palhaugen@gmail.com. 98 T. Fladby et al. / Detecting At-Risk AD Casesmild cognitive impairment. Subjects underwent a clinical and cognitive examination and MRI according to standardized protocols. Core biomarkers in CSF from 411 and APOE genotype from 445 subjects were obtained. Cases (both self-referrals (n = 180) and memory clinics referrals (n = 87)) had increased fractions of pA␤ and APOE ε4 frequency compared to NC. Also, NCFD had higher APOE ε4 frequencies without increased fraction of pA␤ compared to NC, and cases recruited from memory clinics had higher fractions of pA␤ and APOE ε4 frequency than self-referred. This study shows that memory clinic referrals are pA␤ enriched, whereas self-referred and NCFD cases more frequently are pA␤ negative but at risk (APOE ε4 positive), suitable for primary intervention.

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Background/Objective: In recent years, several slightly younger cohorts have been established in order to study the preclinical and prodromal phases of dementia. The Consortium to Establish a Registry for Alzheimer's Disease (CERAD) wordlist memory test (WLT) is widely used in dementia research. However, culturally adapted and demographically adjusted test norms for younger ages are lacking. Method: This paper investigates effects of age, gender and years of education on test performance and offers demographically adjusted norms for the CERAD WLT using a regression-based norming procedure for the age span 40-80 years based on healthy controls (n ¼ 227) from the Norwegian "Dementia Disease Initiation" (DDI) (n ¼ 168) and "Trønderbrain" (n ¼ 59) cohorts. In order to evaluate normative performance, we apply the norms to an independent sample of persons diagnosed with mild cognitive impairment (MCI ¼ 168) and perform multiple regression analyses to evaluate adjustment of pertinent demographics. Results: CERAD WLT norms adjusted for effects of age, gender and educational level are proposed. The norms successfully adjusted for effects of age, gender and education in an independent sample of Norwegians with MCI. Conclusion: Demographically adjusted norms for the CERAD WLT for ages 40-80 years based on a Norwegian sample are proposed. To our knowledge, this is the first normative study of this test to offer demographically adjusted norms for this age span.

Objective: The trail making test (TMT) is one of the most widely used neuropsychological tests. TMT-A provides measures of visual scanning/visuomotor speed and TMT-B involves additional demands on executive functions. Derived scores TMT B-A and TMT B/A enhance measures of executive functioning. However, simple B-A subtraction may lead to false estimates of executive dysfunction in clinical samples. Norms for TMT have been published in several countries but are currently lacking for Scandinavia. Methods: A total of 292 healthy controls between age 41 and 84 years were included from the Norwegian "Dementia Disease Initiation" (DDI) study (n ¼ 170) and the Gothenburg Mild Cognitive Impairment (MCI) study (n ¼ 122). We used a regression-based procedure to develop demographically adjusted norms for basic (TMT-A and TMT-B) and derived measures (TMT B-A and B/A). We also propose a regression-based alternative to the TMT B-A measure named "TMT-b". The proposed norms were compared to norms from Heaton et al. and Tombaugh. Results: Due to differences in the estimated normative effects of demographics on performance, the proposed norms for TMT were better suited in the Scandinavian sample compared with published non-Scandinavian norms. The proposed TMT-b measure was highly correlated to TMT B-A (r ¼ 0.969, p < 0.001). Conclusion: We here propose demographically adjusted norms for the TMT for ages 41 through 84 years based on a Scandinavian ARTICLE HISTORY