Lack of practice effects on neuropsychological tests as early cognitive markers of Alzheimer disease?

Reliable assessment of change from previous cognitive functioning is a prerequisite for determining the possible presence of neurodegenerative diseases such as Alzheimer's disease (AD). We investigated whether standardized change scores on the German version of the Consortium to Establish a Registry for Alzheimer's Disease-Neuropsychological Assessment Battery (CERAD-NAB) could be used for early diagnosis of AD and whether change scores on the CERAD-NAB are superior in this respect to scores recorded on 1 occasion only. Three hundred seventy-four normal control subjects were assessed twice. Data from 95 patients with mostly mild probable AD were collected at their first entry to a memory clinic and an average of 1.1 +/- 0.24 years later. It is concluded that repeated testing with the CERAD-NAB does not generally add to improved diagnostic accuracy for mild and very mild AD and cannot, therefore, be recommended as a routine clinical procedure

Assessment of everyday behavior in Alzheimer's disease patients : its significance for diagnostics and prediction of disease progression

In addition to cognitive decline, current diagnostic criteria for Alzheimer's disease (AD) require evidence of impaired social and/or occupational functioning. The Nurses' Observation Scale for Geriatric Patients (NOSGER) is used to rate the frequency of disturbances in everyday behaviors and, although not specifically developed for this purpose, is often applied for diagnostic purposes. The NOSGER assesses six dimensions: Memory, Instrumental Activities of Daily Living (IADLs), Self-Care (ADL), Mood, Social Behavior, and Disturbing Behavior. The goals of this study were 1) to establish normative data for the NOSGER as a function of demographic variables (i.e., age, years of education, and gender) in healthy elderly subjects; 2) to obtain cutoff values distinguishing healthy elderly subjects from probable AD patients with mild dementia; and 3) to describe the natural course of behavioral changes occurring in mild AD according to the NOSGER dimensions. NOSGER data of 445 normal controls [NCs, 376 men, 69 women; Mini-Mental Status Examination (MMSE) = 28.8 +/- 1.17] and 217 probable AD patients with mild dementia (97 men, 120 women; MMSE = 26.1 +/- 1.59) from the Memory Clinic of Basel, Switzerland, were analyzed. Cutoff scores for distinguishing between average NCs and mildly demented AD patients ranged between 7 and 9 for different NOSGER dimensions. Formulae to obtain demographically adjusted and z-transformed NOSGER dimension and MMSE scores for assessment of individual cases were determined. NCs were best distinguished from patients in the NOSGER dimension Mood, followed by Memory, ADLs, Social Behavior, and Disturbing Behavior. Linear courses of behavioral deterioration were found-in four NOSGER dimensions (Memory, IADLs, Mood, and Social Behavior) in these mildly demented patients. No quadratic course was found for any of the NOSGER dimensions. The NOSGER revealed good discriminatory power in those behavioral dimensions affected in early stages of AD and is suitable for monitoring behavioral changes as a function of disease progression. Its use in combination with the MMSE for dementia screening purposes is recommended

Norms for change in episodic memory as a prerequisite for the diagnosis of mild cognitive impairment (MCI)

The new diagnostic criteria for mild cognitive impairment (MCI) from the International Working Group on Mild Cognitive Impairment (Winblad et al., 2004, p. 243) list "evidence of decline over time in objective cognitive tasks" as one diagnostic sign, implying the repeated neuropsychological testing. This study aimed to compare different assessment methods of longitudinal change based on the performances of 366 cognitively healthy participants (237 men, 129 women) examined with a German version of the California Verbal Learning Test (Delis, Kramer, Kaplan, & Ober, 1987) at baseline and 2 years later. Age, education, gender, and baseline performance were taken into account. Results revealed marked practice effects after 2 years. Normal ranges for change that controls for practice effects and regression to the mean proved to be superior to other reliable change indexes. This new method allows for more valid interpretation of change in neuropsychological functioning and thus diagnosis of MCI

Impact of APOE status on cognitive maintenance in healthy elderly persons

OBJECTIVE: The epsilon4 allele, a variant of the apolipoprotein E (ApoE) gene, is the most prominent genetic risk factor for sporadic, non-familial Alzheimer's disease (AD) currently known. We investigated the impact of the ApoE-epsilon4 status on cognitive performance at repeated test administration in elderly non-symptomatic persons, with a specific focus on practice effects. METHODS: Three hundred and fifty-five physically and mentally healthy participants of the Basel Study on the Elderly (119 F, 236 M; age 68.3 +/- 7.6; years of education 12.7 +/- 3.1; Mini-Mental State scores 29.0 +/- 1.0) were grouped into ApoE epsilon4 carriers and ApoE epsilon4 non-carriers (36.9% and 63.1% of the sample, respectively). Participants were assessed at the beginning of the longitudinal study and on average two years later by means of the California Verbal Learning Test (CVLT) and the Consortium to Establish a Registry for Alzheimer's Disease-Neuropsychological Assessment Battery (CERAD-NAB), a multidimensional cognitive test battery. Baseline and change scores were analyzed with multiple regression procedures and adjusted for age, education and gender; change scores were also adjusted for baseline performance. RESULTS: The ApoE epsilon4 non-carriers showed slightly better performance with regard to most cognitive parameters at baseline. Mean practice effects of the ApoE epsilon4 non-carriers in 12 out of 13 CVLT variables and in five out of the nine main CERAD-NAB variables were above the 50th percentile, while those of the ApoE epsilon4 carriers were below the 50th percentile in the respective distributions of test-retest change scores. CONCLUSIONS: The ε4 allele of the ApoE gene has a negative impact on cognitive performance, notably on episodic memory functions, in physically and mentally healthy aged persons. Practice effects seen in carriers of the ApoE ε4 were inferior in most areas tested to the effects seen in ApoE ε4 non-carriers. Further follow-up of these subjects will help to determine the clinical significance of these findings. Copyright © 2008 John Wiley & Sons, Ltd

Call for uniform neuropsychological assessment after aneurysmal subarachnoid hemorrhage: Swiss recommendations.

BACKGROUND In a high proportion of patients with favorable outcome after aneurysmal subarachnoid hemorrhage (aSAH), neuropsychological deficits, depression, anxiety, and fatigue are responsible for the inability to return to their regular premorbid life and pursue their professional careers. These problems often remain unrecognized, as no recommendations concerning a standardized comprehensive assessment have yet found entry into clinical routines. METHODS To establish a nationwide standard concerning a comprehensive assessment after aSAH, representatives of all neuropsychological and neurosurgical departments of those eight Swiss centers treating acute aSAH have agreed on a common protocol. In addition, a battery of questionnaires and neuropsychological tests was selected, optimally suited to the deficits found most prevalent in aSAH patients that was available in different languages and standardized. RESULTS We propose a baseline inpatient neuropsychological screening using the Montreal Cognitive Assessment (MoCA) between days 14 and 28 after aSAH. In an outpatient setting at 3 and 12 months after bleeding, we recommend a neuropsychological examination, testing all relevant domains including attention, speed of information processing, executive functions, verbal and visual learning/memory, language, visuo-perceptual abilities, and premorbid intelligence. In addition, a detailed assessment capturing anxiety, depression, fatigue, symptoms of frontal lobe affection, and quality of life should be performed. CONCLUSIONS This standardized neuropsychological assessment will lead to a more comprehensive assessment of the patient, facilitate the detection and subsequent treatment of previously unrecognized but relevant impairments, and help to determine the incidence, characteristics, modifiable risk factors, and the clinical course of these impairments after aSAH