In neurological patients, a lack of insight into their impairments can lead to possibly dangerous situations and non-compliance in rehabilitation
therapy with worse rehabilitation outcomes as a result. This so called
anosognosia is a multifaceted syndrome that can occur after brain damage affecting different neurological or cognitive functions. To our knowledge no study has investigated
anosognosia for
apraxia of common tool-use (CTU) so far. CTU-
apraxia is a disorder frequently occurring after
stroke that affects the use of familiar objects. Here, we introduce a new questionnaire to diagnose
anosognosia for CTU-
apraxia, the Visual Analogue Test assessing
Anosognosia for Naturalistic Action Tasks (VATA-
NAT). This assessment is adapted from a series of VATA-questionnaires that evaluate insight into motor (VATA-M) or language (VATA-L) impairment and take known challenges such as
aphasia into account. Fifty one subacute
stroke patients with left (LBD) or right (RBD) brain damage were investigated including patients with and without CTU-
apraxia. Patients were assessed with the VATA-L, -M and -
NAT before and after applying a diagnostics session for each function. Interrater reliability, composite reliability as well as convergent and divergent validity were evaluated for the VATA-
NAT. Seven percent of the LBD patients with CTU-
apraxia demonstrated
anosognosia. After tool-use diagnostics this number increased to 20 percent. For the VATA-
NAT, psychometric data revealed high interrater-reliability (τ ≥ 0.828), composite reliability (CR ≥ 0.809) and convergent validity (τ = -0.626). When assessing patients with severe
aphasia, the possible influence of language comprehension difficulties needs to be taken into account for interpretation. Overall, close monitoring of
anosognosia over the course of rehabilitation is recommended. With the VATA-
NAT we hereby provide a novel assessment for
anosognosia in patients with CTU-
apraxia. For diagnosing
anosognosia we recommend to combine this new tool with the existing VATA-M and -L subtests, particularly in patients who demonstrate severe functional deficits.