Abstract
BackgroundDue to heterogeneous clinical presentation, difficult differential diagnosis with Alzheimer’s disease (AD) and psychiatric disorders, and evolving clinical criteria, the epidemiology and natural history of frontotemporal lobar degeneration (FTD) remain elusive. In order to better characterize FTD patients, we relied on the database of a regional memory clinic network with standardized diagnostic procedures and chose AD patients as a comparator.MethodsPatients that were first referred to our network between January 2010 and December 2016 and whose last clinical diagnosis was degenerative or vascular dementia were included. Comparisons were conducted between FTD and AD as well as between the different FTD syndromes, divided into language variants (lvFTD), behavioral variant (bvFTD), and FTD with primarily motor symptoms (mFTD). Cognitive progression was estimated with the yearly decline in Mini Mental State Examination (MMSE).ResultsAmong the patients that were referred to our network in the 6-year time span, 690 were ultimately diagnosed with FTD and 18,831 with AD. Patients with FTD syndromes represented 2.6% of all-cause dementias. The age-standardized incidence was 2.90 per 100,000 person-year and incidence peaked between 75 and 79 years. Compared to AD, patients with FTD syndromes had a longer referral delay and delay to diagnosis. Patients with FTD syndromes had a higher MMSE score than AD at first referral while their progression was similar. mFTD patients had the shortest survival while survival in bvFTD, lvFTD, and AD did not significantly differ. FTD patients, especially those with the behavioral variant, received more antidepressants, anxiolytics, and antipsychotics than AD patients.ConclusionsFTD syndromes differ with AD in characteristics at baseline, progression rate, and treatment. Despite a broad use of the new diagnostic criteria in an organized memory clinic network, FTD syndromes are longer to diagnose and account for a low proportion of dementia cases, suggesting persistent underdiagnosis. Congruent with recent publications, the late peak of incidence warns against considering FTD as being exclusively a young-onset dementia.
Highlights
Due to heterogeneous clinical presentation, difficult differential diagnosis with Alzheimer’s disease (AD) and psychiatric disorders, and evolving clinical criteria, the epidemiology and natural history of frontotemporal lobar degeneration (FTD) remain elusive
The proportion of FTD syndromes was higher in the Memory Resources and Research Center (MRRC) (8.1%) than elsewhere (2.0%)
The main findings of the present study are threefold: (1) despite new sets of criteria, diagnoses of FTD syndromes remained low in routine care in our regional memory clinic network; when diagnosed, behavioral variant of FTD (bvFTD) patients had longer referral delay and diagnostic wandering than AD patients; (2) the peak of incidence of bvFTD occurred between 75 and 79 years, clearly advocating against the conception of FTD as exclusively an early-onset dementia; (3) FTD syndromes differed from AD with regard to cognition and autonomy at baseline, cognitive decline, and disease duration; and (4) therapeutic strategies radically differed from the ones in AD
Summary
Due to heterogeneous clinical presentation, difficult differential diagnosis with Alzheimer’s disease (AD) and psychiatric disorders, and evolving clinical criteria, the epidemiology and natural history of frontotemporal lobar degeneration (FTD) remain elusive. Frontotemporal lobar degeneration (FTD) is the second leading cause of early-onset dementia after Alzheimer’s disease (AD) [1]. The nosology of FTD has evolved outstandingly, prompting changes in diagnostic criteria. The behavioral variant of FTD (bvFTD) is defined by an early and prominent behavioral and dysexecutive syndrome, whose core symptoms were revised by Rascovsky et al in 2011 [3]. The two language variants of FTD (lvFTD) include the semantic and non-fluent presentations of primary progressive aphasia (PPA), defined by updated clinical criteria [4]. FTD can initially present with motor symptoms (mFTD) such as features of atypical parkinsonism (progressive supranuclear palsy [PSP] and corticobasal syndrome [CBS]) [5]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
