title: Symptom validity testing in memory clinics: Hippocampal-memory associations and relevance for diagnosing mild cognitive impairment.
abstract: Patients with mild cognitive impairment (MCI) do not always convert to dementia. In such cases, abnormal neuropsychological test results may not validly reflect cognitive symptoms due to brain disease, and the usual brain-behavior relationships may be absent. This study examined symptom validity in a memory clinic sample and its effect on the associations between hippocampal volume and memory performance. Eleven of 170 consecutive patients (6.5%; 13% of patients younger than 65 years) referred to memory clinics showed noncredible performance on symptom validity tests (SVTs, viz. Word Memory Test and Test of Memory Malingering). They were compared to a demographically matched group (n = 57) selected from the remaining patients. Hippocampal volume, measured by an automated volumetric method (Freesurfer), was correlated with scores on six verbal memory tests. The median correlation was r = .49 in the matched group. However, the relation was absent (median r = -.11) in patients who failed SVTs. Memory clinic samples may include patients who show noncredible performance, which invalidates their MCI diagnosis. This underscores the importance of applying SVTs in evaluating patients with cognitive complaints that may signify a predementia stage, especially when these patients are relatively young.
authors.affiliation: Department of Brain & Cognition, University of Amsterdam, Amsterdam, The Netherlands. a.rienstra@uva.nl
authors.forename: Anne
authors.initials: A
authors.lastname: Rienstra
authors.forename: Paul F C
authors.initials: PF
authors.lastname: Groot
authors.forename: Pauline E J
authors.initials: PE
authors.lastname: Spaan
authors.forename: Charles B L M
authors.initials: CB
authors.lastname: Majoie
authors.forename: Aart J
authors.initials: AJ
authors.lastname: Nederveen
authors.forename: Gerard J M
authors.initials: GJ
authors.lastname: Walstra
authors.forename: Jos F M
authors.initials: JF
authors.lastname: de Jonghe
authors.forename: Willem A
authors.initials: WA
authors.lastname: van Gool
authors.forename: Silvia D
authors.initials: SD
authors.lastname: Olabarriaga
authors.forename: Vladimir V
authors.initials: VV
authors.lastname: Korkhov
authors.forename: Ben
authors.initials: B
authors.lastname: Schmand
mesh_terms: D000368:Aged; D060825:Cognitive Dysfunction / Q000175:diagnosis* / Q000503:physiopathology / Q000523:psychology*; D003627:Data Interpretation, Statistical; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D006624:Hippocampus / Q000473:pathology / Q000503:physiopathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008306:Malingering / Q000175:diagnosis / Q000523:psychology; D008568:Memory / Q000502:physiology; D008569:Memory Disorders / Q000175:diagnosis* / Q000209:etiology / Q000523:psychology*; D001523:Mental Disorders / Q000150:complications / Q000523:psychology; D011939:Mental Recall / Q000502:physiology; D008875:Middle Aged; D009483:Neuropsychological Tests; D011569:Psychiatric Status Rating Scales; D011597:Psychomotor Performance / Q000502:physiology; D021641:Recognition, Psychology / Q000502:physiology; D015203:Reproducibility of Results; D014706:Verbal Learning / Q000502:physiology