The Pitfall of Behavioral Variant Frontotemporal Dementia Mimics Despite Multidisciplinary Application of the FTDC Criteria

Article type: Research Article

Authors: Krudop, Welmoed A.^{a; *} | Dols, Annemieke^{b; c; e} | Kerssens, Cora J.^b | Eikelenboom, Piet^b | Prins, Niels D.^{a; d} | Möller, Christiane^a | Schouws, Sigfried^b | Rhebergen, Didi^{b; c; e} | van Exel, Eric^{b; c; e} | van der Flier, Wiesje M.^{a; f} | Sikkes, Sietske^{a; f} | Scheltens, Philip^a | Stek, Max L.^{b; c} | Pijnenburg, Yolande A.L.^a

Affiliations: [a] Alzheimer Center and Department of Neurology, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, The Netherlands | [b] Department of Old Age Psychiatry, GGZInGeest/ VU University Medical Center, Amsterdam, The Netherlands | [c] Amsterdam Public Health Research Institute, VU University Medical Center Amsterdam, The Netherlands | [d] Brain Research Center, Amsterdam, The Netherlands | [e] Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, The Netherlands | [f] Department of Epidemiology and Biostatistics, VU University Medical Center, Amsterdam, The Netherlands

Correspondence: [*] Correspondence to: Welmoed A. Krudop, MD, Alzheimer Centre and Department of Neurology, VU University Medical Center, De Boelelaan 1117, 1081 HV Amsterdam, 1007 MB, Amsterdam, The Netherlands. Tel.: +31 204448523; E-mails: [email protected]; [email protected].

Abstract: Background:The behavioral variant of frontotemporal dementia (bvFTD) has a broad differential diagnosis including other neurological and psychiatric disorders. Psychiatric misdiagnoses occur in up to 50% of bvFTD patients. Numbers on misdiagnosis of bvFTD in psychiatric disorders are lacking. Objective:The aim of our study was to investigate the frequency and characteristics of bvFTD misdiagnoses in psychiatric disorders and other neurologic disorders. Methods:Thirty-five patients with a (possible or probable) bvFTD diagnosis made by specialized memory clinic neurologists were included. Change in diagnosis after consulting a psychiatrist at baseline was recorded as well as change in diagnosis after two years of multidisciplinary neuropsychiatric follow-up. Differences in cognitive and behavioral profiles were investigated per diagnostic group after follow-up (bvFTD, psychiatry, other neurologic disorders). Clinical profiles are described in detail. Results:In 17 patients (48.5%), the bvFTD baseline diagnosis changed: Two at baseline after psychiatric consultation, and 15 after two years of multidisciplinary follow-up. Eleven (64.5%) of these 17 patients (31.5% of total) were reclassified with a psychiatric diagnosis. We found no differences for cognitive baseline profiles between patients with bvFTD versus psychiatric diagnoses. Conclusion:In almost half of cases, the initial bvFTD diagnosis was changed after follow-up, most often into a psychiatric disorder. A multidisciplinary neuropsychiatric approach in the diagnostic process of bvFTD results in the identification of treatable disorders. Our findings illustrate a limited specificity of the [18F]FDG-PET-scan and the bvFTD criteria in a neuropsychiatric cohort, especially combined with certain clinical symptoms, like disinhibition, apathy, or loss of empathy.

Keywords: Behavioral variant FTD, differential diagnosis, frontotemporal dementia, psychiatry

DOI: 10.3233/JAD-170608

Journal: Journal of Alzheimer's Disease, vol. 60, no. 3, pp. 959-975, 2017