Frontotemporal dementia
Frontotemporal dementia (FTD) is the second most common neurodegenerative dementia in patients under 65, comprising a behavioral variant marked by early personality and disinhibition change and language variants (primary progressive aphasia) marked by isolated progressive language decline. Diagnosis rests on clinical criteria supported by MRI or FDG-PET showing frontotemporal atrophy; there is no approved disease-modifying or symptomatic drug therapy.
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What this article covers
- Overview
Definition: frontotemporal dementia (FTD) is a group of neurodegenerative syndromes caused by selective frontal and/or temporal lobe atrophy, presenting as a behavioral variant (early personality and…
- Epidemiology
Age of onset: typically presents between ages 45 and 65, younger than typical Alzheimer disease onset.
- Risk factors
Family history/genetic mutation: a family history of early-onset dementia or ALS is the strongest identifiable risk factor, given the high familial rate of behavioral-variant FTD.
- Pathophysiology
Selective frontal and temporal lobe atrophy: progressive neuronal loss underlies both phenotypes, with the pattern and laterality of atrophy shaping the specific clinical syndrome.
- Clinical features
Alteration in personality and behavior is the most prominent early feature of behavioral-variant FTD, typically developing years before measurable cognitive impairment, and is often mistaken for a…
- Differential diagnosis
Alzheimer disease: early and prominent episodic memory loss with relatively preserved personality early in the disease, the reverse of the behavioral-variant FTD pattern, and a low cerebrospinal…
- Diagnosis
Diagnosis of behavioral-variant FTD is established when a patient meets at least 3 of the 6 core clinical criteria (disinhibition, apathy/inertia, loss of sympathy/empathy, perseverative/compulsive…
- Management
Acetylcholinesterase inhibitors (such as donepezil) and memantine, the mainstay Alzheimer disease drugs, have shown no benefit in FTD trials and should not be used.
- Complications
Progressive loss of independence: executive dysfunction and behavioral disturbance impair employment, finances, and social functioning earlier than memory loss typically does in Alzheimer disease.
- Prognosis
Progressive and ultimately fatal: FTD is a relentlessly progressive neurodegenerative disease without a disease-modifying treatment; overall survival is typically shorter than in Alzheimer disease.
- Prevention
No proven strategy prevents FTD itself, since the disease is driven by neurodegenerative tau, TDP-43, or FUS pathology without an established modifiable environmental cause.
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