Kurz und einfach ist nicht immer besser: Grenzen kognitiver Demenzscreenings

Zusammenfassung

Kognitive Demenzscreenings erfreuen sich großer Beliebtheit. Dies ist auch eine Folge des üblichen Validierungsansatzes, der vorab definierte Patientengruppen vergleicht und so oftmals zu einer Überschätzung der Trennschärfe führt. 8 Patienten mit leichter Alzheimer-Demenz (AD) und 17 Kontrollpersonen wurden zwei Jahre nach Diagnosestellung untersucht. Appliziert wurden vier Kurztests sowie zwei elaborierte Testprozeduren, darunter ein lernpotenzialorientiertes Paradigma. Neben traditionellen Gruppenvergleichen wurde explorativ eine Clusteranalyse gerechnet. Während der Vergleich vorab definierter Gruppen für nahezu alle Verfahren signifikante Leistungsunterschiede zwischen AD-Patienten und Kontrollen auswies, gelang bei clusteranalytischer Auswertung eine ausreichend sichere Klassifikation lediglich anhand der elaborierten Testverfahren. Die Ergebnisse raten zur Vorsicht beim Einsatz von Demenzscreenings. Gleichzeitig verdeutlichen sie das Potenzial plastizitätsbasierter Teststrategien.

Abstract

The increasing prevalence of Alzheimer’s dementia (AD) and limited resources in outpatient care have encouraged the distribution of cognitive screening tests, in spite of their frequently unsatisfying accuracy regarding the differentiation between incipient AD, depression and age-associated memory impairment. 8 patients with probable AD and 17 controls completed a neuropsychological follow-up two years after initial examination. Beside four screening tests a memory based testing-the-limits (TtL) paradigm as well as the German version of the California Verbal Learning Test were administered. Based on hierarchical cluster analysis we could demonstrate that only well elaborated tests, such as a plasticity based TtL paradigm, did classify AD-patients correctly. The findings confirm reservations against cognitive screening procedures in detecting dementia and suggest that dynamic test strategies offer a powerful diagnostic alternative to traditional status-oriented tests.

Schlüsselwörter

Alzheimer-Demenz - Frühdiagnostik - Kognition - Screening - Lernpotenzial

Schlüsselwörter

Alzheimer’s disease - early diagnosis - cognition - screening - plasticity

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