Frontotemporal dementia (FTD) is a group of disorders in which neurodegeneration chiefly affects brain areas called the frontal and temporal lobes. No single underlying pathological process is known.
FTD, once considered rare, is now thought to account for up to 10 to 15 percent of all dementia cases.
FTD types are placed in one of two basic clinical groups:
The first group is defined by behavioral and personality changes that may include uncharacteristic impulsiveness and lack of inhibition; rudeness or tactlessness; poor financial judgment; inappropriate social conduct, sometimes extending into illegal activities; declining interest in grooming and hygiene; and overeating and weight gain. Individuals typically lack insight into such changes. This group of FTDs includes the well-known Pick's disease.
The second group is characterized by progressive disruption in verbal and written expression (primary progressive aphasia) or naming and understanding meaning (semantic dementia). Memory and other cognitive functions remain relatively unaffected.
It tends to occur earlier than Alzheimer's, primarily between ages 35 and 75. Due to its earlier onset and prominent behavioral and personality symptoms, it may be mistaken for a primary psychiatric disorder.
Most individuals with FTD perform poorly on neuropsychiatric tests of executive function.
Brain imaging often shows damage to the anterior temporal and frontal lobes. If present, this atrophy may be diagnostic. Distinguishing FTD from Alzheimer's is the only indication for which Medicare may cover a PET scan for evaluation of dementia.
No treatments are approved by the FDA for frontotemporal dementia, and none have been shown to be effective.
No specific abnormality is associated with all cases of frontotemporal dementia. An alternate term for FTD is "dementia lacking distinct histopathologic features."