Parkinsonism in
frontotemporal dementia (FTD) was first described in families with mutations in the
microtubule-associated protein tau (MAPT) and
progranulin (PRGN) genes. Since then, mutations in several other genes have been identified for FTD with
parkinsonism, including chromosome 9 open reading frame 72 (C9ORF72),
chromatin modifying
protein 2B (CHMP2B),
valosin-containing protein (VCP), fused in
sarcoma (FUS) and transactive
DNA-binding protein (TARDBP). The clinical presentation of patients with familial forms of FTD with
parkinsonism is highly variable. The
parkinsonism seen in FTD patients is usually characterized by akinetic-rigid syndrome and is mostly associated with the behavioral variant of FTD (bvFTD); however, some cases may present with classical
Parkinson's disease. In other cases, atypical
parkinsonism resembling
progressive supranuclear palsy (PSP) or
corticobasal syndrome (CBS) has also been described. Although rare,
parkinsonism in FTD may coexist with
motor neuron disease. Structural neuroimaging, which is crucial for the diagnosis of FTD, shows characteristic patterns of brain
atrophy associated with specific mutations. Structural neuroimaging is not helpful in distinguishing among patients with parkinsonian features. Furthermore, dopaminergic imaging that shows nigrostriatal neurodegeneration in FTD with
parkinsonism cannot discriminate
parkinsonian syndromes that arise from different mutations. Generally,
parkinsonism in FTD is
levodopa unresponsive, but there have been cases where a temporary benefit has been reported, so dopaminergic treatment is worth trying, especially, when motor and non-motor manifestations can cause significant problems with daily functioning. In this review, we present an update on the clinical and genetic correlations of FTD with
parkinsonism.