Movement disorders

Many patients with FTD develop, or even present with, Parkinsonian features. In classical Parkinson's disease (PD), a tremor is often present and the rigidity tends to involve the limbs, while in FTD, a tremor is often absent and the rigidity is usually axial. Falls at presentation or early in the disease course, poor response to levodopa, symmetry of motor signs, rapid progression, lack of tremor and early dysautonomia are signs that identify patients with forms of parkinsonism other than PD. A significant loss of smell suggests PD. Progressive supranuclear palsy (PSP) can cause difficulty with speech and swallowing, as well as depression and emotional difficulties. Alien limb suggests corticobasal degeneration (CBD) more than FTD or PD.

Like FTD, confusion and memory loss similar to early Alzheimer's do not occur in people with PD until late in the disease. Language and thinking problems are likely develop in someone with CBD or dementia with Lewy bodies (DLB).

Formal eye movement recordings may be useful to distinguish PD and other forms of parkinsonism from FTD.

MRI and CT appear normal in PD, whereas the MRI of someone with FTD will typically show some atrophy in the frontal and anterior temporal lobes. MRIs of people with multiple system atrophy (MSA) may show abnormalities in the putamen (the so-called hot-cross bun sign). PET may show low levels of dopaminergic activity in PD.

Up to 50% of amyotrophic lateral sclerosis (ALS) patients also show loss of executive function and up to 20% have full-blown signs and symptoms of frontotemporal dementia. As a result, patients may lack the ability to fully understand the meaning of their illness, they may make poor decisions about their clinical care, or they may become agitated and difficult for caregivers who are trying to help them. They may have language problems that go beyond the expressive difficulties in ALS or show behavioral changes years before the ALS manifests.