The Newly Normed SKT Reveals Differences in Neuropsychological Profiles of Patients with MCI, Mild Dementia and Depression

Abstract

The SKT (Syndrom-Kurztest) is a short cognitive performance test assessing deficits of memory and attention in the sense of speed of information processing. The new standardization of the SKT (2015) aimed at improving its sensitivity for early cognitive decline due to dementia in subjects aged 60 or older. The goal of this article is to demonstrate how the neuropsychological test profile of the SKT can be used to provide valuable information for a differential diagnosis between MCI (mild cognitive impairment), dementia and depression. n = 549 patients attending a memory clinic (Nuremberg, Germany) were diagnosed according to ICD-10 and tested with the SKT. The SKT consists of nine subtests, three for the assessment of memory and six for measuring attention in the sense of speed of information processing. The result of the SKT test procedure is a total score, which indicates the severity of overall cognitive impairment. Besides the summary score, two subscores for memory and attention can be interpreted. Using the level of depression as a covariate, statistical comparisons of SKT test profiles between the three patient groups revealed that depressed patients showed more pronounced deficits than MCI patients in all six attention subtests. On the other hand, MCI patients displayed significantly greater mnestic impairment than the depressed group, which was indicated by significant differences in the memory subscore. MCI and dementia patients showed similar deficit patterns dominated by impairment of memory (delayed recall) with MCI patients demonstrating less overall impairment. In sum, the SKT neuropsychological test profiles provided indicators for a differential diagnosis between MCI and beginning dementia vs. depression.

The Application of the SKT Short Cognitive Performance Test to English-Speaking Populations

“…Cross-validations on clinical samples should be carried out to investigate whether the English regression-based norming of the SKT is suitable as a reliable assessment of cognitive disorders, especially in the area of MCI, and how well the results of the SKT correspond to the clinical diagnoses of experts (cf. [23]).…”

Diagnosis of Dementia and Cognitive Impairment

“…New data on the use of TYM in a general neurology clinic and as a telephone-administered test are presented, suggesting potential value in these settings [6]. Hartmut Lehfeld and Mark Stemmler demonstrate the potential utility of the Syndrom Kurtztest (SKT), a short cognitive performance test addressing memory and attention, the latter related to the speed of information processing [7]. Ronan O'Caoimh and William Molloy compare the standardised Mini-Mental State Examination (sMMSE) to the Quick Mild Cognitive Impairment (Qmci) screen, finding the latter to have similar or greater accuracy in distinguishing all dementia subtypes and particularly MCI [8].…”

“…O'Caoimh and Molloy suggest that comorbid depression may influence performance on cognitive testing in different ways depending on the stage of cognitive impairment, more so at earlier stages, perhaps increasing the risk of conversion to dementia [8]. Lehfeld and Stemmler show how the subtests of the SKT, examining memory and attention (speed of information processing), may assist in the differential diagnosis of depression versus MCI/mild dementia [7].…”