Frontotemporal lobar degeneration-associated syndromes common across Europe

The incidence of frontotemporal labor degeneration-associated disorders is more common in Europe than previously thought, with an estimated 12,057 new cases per year, researchers reported in JAMA Neurology.

“Frontotemporal lobar degeneration (FTLD) is a complex family of neuropathological conditions characterized by a spectrum of focal neurodegeneration with atrophy of the frontal and temporal lobes and a wide range of clinical, genetic and neuropathological features,” Giancarlo Logroscino, MD, of the University of Bari-Aldo Moro in Lecce, Italy, and colleagues wrote.

Logroscino and colleagues conducted the Frontotemporal Dementia Incidence European Research Study (FRONTIERS), a retrospective cohort study designed to assess the incidence of FTLD across Europe. Researchers drew data from a population-based registry from 13 FTLD clinics in the United Kingdom, the Netherlands, Finland, Sweden, Spain, Bulgaria, Serbia, Germany and Italy.

Eligible participants met criteria for the behavioral variant of frontotemporal dementia (BVFTD), the nonfluent variant or semantic variant of primary progressive aphasia (PPA), unspecified PPA, progressive supranuclear palsy, corticobasal syndrome or frontotemporal dementia with ALS (FTD-ALS).

Researchers identified 267 incident cases (mean age, 66.7 years; 58.43% men) and estimated the annual incidence rate for FTLD in Europe to be 2.36 cases per 100,000 person-years (95% CI, 1.59-3.51 cases).

In addition, they reported a progressive increase in FTLD incidence with age, peaking at age 71 years, with 13.09 cases per 100,000 person-years (95% CI, 8.46-18.93 cases) among male participants and 7.88 cases per 100,000 person-years among female participants (95% CI, 5.39-11.6 cases). Incidence was higher among men (2.84 cases per 100,000; 95% CI, 1.88-4.27) compared with women (1.91 cases per 100,000; 95% CI, 1.26-2.91).

Researchers also reported that BVFTD was the most common phenotype diagnosed in participants (107 cases; 40.07%), followed by PPA (76 cases; 28.46%) and extrapyramidal phenotypes (69 cases; 25.84%). Of all phenotypes, FTD-ALS was the least common (15 cases; 5.62%).

“This is a substantial burden on the European health and welfare system that should be seriously considered to provide appropriate health and social care planning and to design future clinical trials,” Logroscino and colleagues wrote. “Further confirmatory prospective studies and further studies with similar design in different geographic areas are needed.”