Atrophy and frontotemporal dementia
The behavioral variant of frontotemporal dementia is a frequent cause of neurodegenerative dementia and the first cause of Frontotemporal Lobular Degeneration. Patients with the behavioral variant of frontotemporal dementia present a progressive personality change that begins years before diagnosis and can be confused with other neurodegenerative and psychiatric diseases. Identifying atrophy or loss of brain volume on MRI studies can aid in the diagnosis. However, at present the study of brain atrophy on MRI is usually based on subjective visual examinations. Recently, various methods have been validated that allow the systematic quantification of brain atrophy using brain magnetic resonance imaging.
What have we done in this study?
In this study we have determined the diagnostic and prognostic value of a group of accessible and reproducible atrophy scales in a large sample of patients with the behavioral variant of frontotemporal dementia recruited in Catalonia and the United States. These measures include various visual scales and the “Magnetic Resonance Parkinsonism Index” or MRPI.
The main finding of this work was that the visual scales made it possible to accurately differentiate patients with a behavioral variant of frontotemporal dementia from patients with other neurodegenerative and psychiatric diseases. The degree of atrophy measured using these scales made it possible to accurately estimate the rate of progression of patients during clinical follow-up. In addition, the MRPI identified patients with two specific causes of frontotemporal lobar degeneration: progressive supranuclear palsy and corticobasal degeneration at autopsy.
Relevance of the study
The quantification of cortical and subcortical atrophy is a useful resource that can be standardized using quantitative and semi-quantitative methods to improve the diagnosis of the behavioral variant of frontotemporal dementia in routine clinical practice. This study demonstrates that reproducible atrophy scales can increase the certainty of the diagnosis of frontotemporal lobar degeneration and help predict prognosis after diagnosis.
Diagnostic Utility of Measuring Cerebral Atrophy in the Behavioral Variant of Frontotemporal Dementia and Association with Clinical Deterioration. Illán-Gala I, Falgàs N Friedberg A, et al., JAMA Netw Open. 2021