The Role of Verb Fluency in the Detection of Early Cognitive Impairment in Alzheimer’s Disease

Article type: Research Article

Authors: Alegret, Montserrat^{a; *} | Peretó, Mar^{a; b} | Pérez, Alba^a | Valero, Sergi^{a; c} | Espinosa, Ana^a | Ortega, Gemma^a | Hernández, Isabel^a | Mauleón, Ana^a | Rosende-Roca, Maitée^a | Vargas, Liliana^a | Rodríguez-Gómez, Octavio^a | Abdelnour, Carla^a | Berthier, Marcelo L.^d | Bak, Thomas H.^e | Ruíz, Agustín^a | Tárraga, Lluís^a | Boada, Mercè^a

Affiliations: [a] Memory Clinic and Research Center of Fundació ACE, Institut Català de Neurociències Aplicades, Barcelona, Spain | [b] Mental Health Research Group, IMIM (Hospital del Mar Research Institute), CIBERSAM (Centro de Investigación Biomédica en Red de Salud Mental), Barcelona, Spain | [c] Department of Psychiatry, Hospital Universitari Vall d’Hebron, CIBERSAM, Universitat Autònoma de Barcelona, Barcelona, Spain | [d] Cognitive Neurology and Aphasia Unit and Cathedra ARPA of Aphasia, Centro de Investigaciones Médico-Sanitarias (CIMES) and Instituto de Investigación Biomédica de Málaga (IBIMA), University of Malaga, Malaga, Spain | [e] Department of Psychology and Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK

Correspondence: [*] Correspondence to: Montserrat Alegret, PhD, Fundació ACE. Institut Català de Neurociències Aplicades, Gran Via Carles III, 85 bis, 08028 Barcelona, Spain. Tel.: +34 93 4304720; Fax: +34 93 4193542; E-mail: malegret@fundacioace.org.

Abstract: Background:Verb fluency (VF) is the less commonly used fluency test, despite several studies suggesting its potential as a neuropsychological assessment tool. Objective:To investigate the presence of VF deficits in mild cognitive impairment (MCI) and mild Alzheimer’s disease (AD) dementia; to assess the usefulness of VF in the detection of cognitively healthy (CH) people who will convert to MCI, and from MCI to dementia; and to establish the VF cut-offs useful in the cognitive assessment of Spanish population. Methods:568 CH, 885 MCI, and 367 mild AD dementia individuals were administered the VF test and a complete neuropsychological battery. Longitudinal analyses were performed in 231 CH and 667 MCI subjects to search for VF predictors of diagnosis conversion. Results:A worsening on VF performance from CH, MCI to AD dementia groups was found. Lower performances on VF were significantly related to conversion from CH to MCI/MCI to dementia. When the effect of time to conversion was analyzed, a significant effect of VF was found on the faster conversion from CH to MCI, but not from MCI to dementia. Moreover, VF cut-off scores and sensitivity/specificity values were calculated for 6 conditions (3 age ranges by 2 educational levels). Conclusion:The VF test may be a useful tool for the differential diagnosis of cognitive failure in the elderly. Since VF deficits seem to take place in early stages of the disease, it is a suitable neuropsychological tool for the detection not only of CH people who will convert to MCI, but also from MCI to dementia.

Keywords: Alzheimer’s disease, cognitively healthy, mild cognitive impairment, verb fluency, verbal fluency

DOI: 10.3233/JAD-170826

Journal: Journal of Alzheimer's Disease, vol. 62, no. 2, pp. 611-619, 2018