Update on the Neuropathological Diagnosis of Frontotemporal Dementias

Abstract

Previous criteria for Frontotemporal Dementia have primarily been designed for research purposes (1–5). An international group of experts on clinical and neuropathological aspects of frontotemporal dementia (FTD) recently re-assessed criteria for the diagnosis of FTD at a meeting entitled “The Frontotemporal Dementia and Pick's Disease Criteria Conference” held at the National Institutes of Health in Bethesda, MD on July 7, 2000 (see ref #1 and the roster of meeting participants in the Acknowledgments). Building upon a substantial literature on these disorders, the goal of the conference was to update previous FTD diagnostic criteria, taking into account recent research advances to refine guidelines for the clinical and neuropathological diagnosis of FTD (1). Here we provide a brief overview of the most salient points of the neuropathology recommendations for disorders included among FTDs. Although Pick's disease can be considered the prototype of FTDs, in the last 3 decades it became increasingly clear to several research groups that there were a number of other distinct FTD variants that lacked the lobar atrophy and related neuropathology of Pick's disease (1). This prompted the use of a number of different names to designate these disorders, including FTD, frontal lobe degeneration of the non-Alzheimer-type, frontotemporal lobar degeneration (FTLD), dementia lacking distinct histopathology (DLDH), progressive aphasia and semantic dementia (1). Moreover, since several kindreds with FTD and parkinsonism linked to chromosome 17 were shown to have pathogenic tau gene mutations, the term FTDP-17 was used to refer to this hereditary group of FTDs, while a less well-characterized disorder in other patients with evidence of FTD as well as clinical and pathological findings of motor neuron disease (MND) has been designated FTD with MND, and hereditary forms of this disease have been linked to chromosome 9 (1). Since these and other terms have been used to refer to …