Frontotemporal Dementia

Frontotemporal dementia (FTD) is an umbrella term for a group of neurodegenerative conditions characterized by progressive degeneration of the frontal and temporal lobes — the brain regions governing personality, behavior, language, and executive function. Unlike Alzheimer's disease, FTD typically spares memory in early stages, making it a frequently misdiagnosed condition.

FTD encompasses several clinical subtypes: behavioral variant FTD (bvFTD), which primarily affects personality, judgment, and social behavior; primary progressive aphasia (PPA), which primarily affects language; and semantic variant PPA, which affects word meaning and object recognition. Each subtype reflects the specific regions most affected by neurodegeneration.

At the pathological level, FTD involves abnormal accumulation of one of several proteins — most commonly TDP-43, tau, or FUS — in frontal and temporal neurons. Different protein types correlate with different clinical presentations and different genetic causes. Genetic mutations in C9orf72, GRN, and MAPT genes account for a significant proportion of familial FTD cases.

FTD is the most common cause of dementia in people under 60 years old, and the third most common cause of dementia overall. Because it affects personality and behavior before memory, it is often misdiagnosed as psychiatric illness — depression, bipolar disorder, or personality disorder — for years before the correct diagnosis is made. Early diagnosis matters because FTD has specific management needs distinct from Alzheimer's.

The behavioral changes in FTD — disinhibition, loss of empathy, socially inappropriate behavior, poor judgment, compulsive behaviors — are often more distressing to families than memory loss and can be dangerous if not appropriately managed. Understanding the neurological basis of these behaviors is essential for caregivers and families navigating the condition.

There are currently no FDA-approved disease-modifying treatments for FTD. Several clinical trials are underway targeting specific FTD genetic subtypes. Symptom management focuses on behavioral interventions and medications to manage specific symptoms like agitation or compulsive behaviors.