Intrusions and provoked and spontaneous confabulations on memory tests in Korsakoff’s syndrome

Abstract

Introduction: Intrusions on verbal memory tests have been used as an index for clinical confabulation. Severe memory impairments in combination with executive dysfunction have been suggested to be the underlying mechanism of confabulation, but to date, this relation is unclear. The aim of this study was (a) to examine the relation between (different types of) intrusions and confabulations in a large sample of confabulating patients with Korsakoff's syndrome (KS) and (b) to investigate whether different measures of executive functioning and memory performance are related to provoked and spontaneous confabulation. Method: The Dutch version of the California Verbal Learning Test (CVLT) and various executive function and memory tests were administered to a group of 51 confabulating patients with KS. Professional caregivers rated the severity of provoked and spontaneous confabulation behavior of the patients using the Nijmegen-Venray Confabulation List-20 (NVCL-20). Results: The total number of intrusions on the CVLT was not related to either provoked or spontaneous confabulation scores. None of the CVLT intrusion scores correlated significantly with any of the confabulation scores, but we did find small-to-medium, positive correlations between unrelated intrusions and both provoked confabulations and spontaneous confabulation. Provoked confabulation behavior was associated with executive dysfunction and poorer memory performances. Spontaneous confabulation was not related to performance on measures of executive function and memory. Conclusions: The total number of intrusions on verbal memory tests and clinical confabulations appear to be different phenomena. Only unrelated intrusions produced on the CVLT might possibly be related to confabulations. The production of provoked, but not spontaneous, confabulation is associated with executive dysfunction and memory deficits.

Korsakoff Syndrome in Non-alcoholic Psychiatric Patients. Variable Cognitive Presentation and Impaired Frontotemporal Connectivity

“…Intrusions in memory testing [provoked confabulations ( 44 ), simple provoked confabulations ( 45 ), memory-recall-provoked confabulations ( 46 )] may occur in normal controls ( 47 ), but they are rare ( 48 , 49 ), unless after a retention interval longer than the one used in clinical assessment ( 44 ). Patients with alcoholic KS commonly produce intrusions ( 23 , 33 ), which are similarly to our patients semantic ( 23 ). In previous studies of neuropsychologically documented non-alcoholic KS, intrusions have been reported in five cases, including the three in our recent report ( 15 , 20 , 50 ), whereas they were absent in one case ( 51 ).…”

“…Intrusions were defined as false words in the Hopkins Verbal Learning Test–Revised (HVLT-R) and false statements in the Wechsler Memory Scale–III (WMS-III). Intrusions semantically related to the presented material were considered semantic ( 23 ).…”

Identification and Evaluation of Neuropsychological Tools Used in the Assessment of Alcohol-Related Cognitive Impairment: A Systematic Review

“…Conversely, no significant correlation was found between the NVCL-20 and the CVLT intrusions variable, questioning the previous use of this as an index of confabulation (e.g., Schnider et al, 1996). Rensen et al's (2017) findings corroborate this concern, finding no correlation between spontaneous and provoked confabulation as measured by the NVCL-20 and the total number of intrusions on the CLVT. However, small but non-significant correlations were found between unrelated intrusions and both forms of confabulation ( r = 0.20 for both analyses), suggesting intrusions unrelated to the information learnt may be more closely associated with confabulations than those related.…”

“…The use of the Intrusions variable of the CVLT as an index of confabulation is questionable. The findings from Rensen, Oosterman, van Damme, Griekspoor, Wester and Kopelman (2015, 2017) suggest intrusions, while related to confabulations, may be distinct phenomena. The NVCL-20 observational scale for measuring confabulatory behavior appears more suitable for assessing confabulation in those with ARCI, demonstrating superior psychometric properties to other measures used for this purpose.…”

“…The early stage of WKS is associated with both provoked and spontaneous confabulations. Accordingly, the assessment of confabulatory behavior may provide important diagnostic information (Borsutzky et al, 2008; Rensen et al, 2017). The use of the Intrusions variable of the CVLT as an index of confabulation is questionable.…”