A Brief Drawing Task for the Differential Diagnosis of Semantic Dementia

Article type: Research Article

Authors: Pozueta, Ana^{a; *} | Lage, Carmen^a | Martínez, María García^a | Kazimierczak, Martha^a | Bravo, María^a | López-García, Sara^a | Riancho, Javier^b | González-Suarez, Andrea^a | Vázquez-Higuera, José Luis^a | de Arcocha-Torres, María^c | Banzo, Ignacio^c | Bonilla, Julio Jimenez^c | Berciano, José^a | Rodríguez-Rodríguez, Eloy^a | Sánchez-Juan, Pascual^a

Affiliations: [a] Neurology Service and Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), ‘Marqués de Valdecilla’ University Hospital, University of Cantabria, Institute for Research ‘Marqués de Valdecilla’ (IDIVAL), Santander, Spain | [b] Neurology Service and Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), ‘Hospital Sierrallana, Institute for Research ‘Marqués de Valdecilla’ (IDIVAL), Santander, Spain | [c] Nuclear Medicine Department, University Hospital Marqués de Valdecilla, University of Cantabria, Molecular imaging Group - IDIVAL, Santander, Spain

Correspondence: [*] Correspondence to: Ana Pozueta Cantudo, PsyS, Servicio de Neurología Hospital, Universitario “Marqués de Valdecilla", Planta Baja Valdecilla Sur; Avda Marqués de Valdecilla s/n, 39011 Santander (Cantabria), Spain. Tel.: +34 942202520/Ext. 73427; E-mail: anapozueta@gmail.com.

Abstract: Background:Semantic dementia (SD) is a subtype of frontotemporal lobe degeneration characterized by semantic loss, with other cognitive functions initially preserved. SD requires differential diagnosis with Alzheimer’s disease (AD) and behavioral variant frontotemporal dementia (bvFTD). Semantic knowledge can be evaluated through different tests; however, most of them depend on language. Objective:We describe the development of a brief drawing task that may be helpful for the differential diagnosis of SD. Methods:Seventy-two patients, including 32 AD, 19 bvFTD, and 21 SD were asked to draw 12 items with different age of acquisition and familiarity, belonging to four different semantic categories. We employed the drawings of healthy volunteers to build a scoring scheme. Results:Turtle, strawberry, train, and envelope were the items of each category that best discriminated between groups and were selected for the Brief drawing task. The discriminatory power of the Brief drawing task between SD versus AD and bvFTD patients, estimated through the area under the curve was 0.84 (95% CI = 0.72–0.96, p = 0.000007). In a logistic model, the Brief drawing task (p = 0.003) and VOSP “number location” subtest (p = 0.016) were significant predictors of the diagnosis of SD versus AD and bvFTD after adjustment by the main covariates. The Brief drawing task provided clinically useful qualitative information. SD drawings were characterized by loss of the distinctive features, intrusions, tendency to prototype, and answers like “I don’t know what this is”. Conclusion:The Brief drawing task appears to reveal deficits in semantic knowledge among patients with SD that may assist in the differential diagnosis with other neurodegenerative diseases.

Keywords: Dementia, differential diagnosis, drawings, semantic dementia, semantic knowledge

DOI: 10.3233/JAD-190660

Journal: Journal of Alzheimer's Disease, vol. 72, no. 1, pp. 151-160, 2019