Parkinsonism is a clinical syndrome characterised by a combination of motor symptoms, most notably bradykinesia (slowness of movement), muscular rigidity, resting tremor, and postural instability. These features resemble those seen in Parkinson’s disease, but parkinsonism can result from a range of underlying neurological conditions including neurodegenerative diseases, certain medications, or vascular causes. Importantly, while Parkinson’s disease is the most well-known and common cause, the presence of parkinsonism does not necessarily indicate a diagnosis of Parkinson’s disease itself.
Disorders Where Parkinsonism May Be Symptomatic #
| Disorder | Parkinsonism? | Comment |
|---|---|---|
| Amnestic variant Alzheimer’s disease | Possible | Not typical early; extrapyramidal signs can appear late or with Lewy body co-pathology. |
| Behavioural variant frontotemporal dementia (bvFTD) | Possible | Often due to underlying PSP/CBD-spectrum pathology; genetic FTD (e.g., MAPT/GRN) may show parkinsonism. Not typically associated with MSA. |
| Creutzfeldt-Jakob disease dementia | Possible | Akinetic-rigid features can emerge, especially later, alongside myoclonus and rapid decline. |
| Corticobasal degeneration (CBD) | Core | Classically asymmetric, levodopa-poor parkinsonism within corticobasal syndrome (CBS). |
| Dementia with Lewy bodies (DLB) | Core | Parkinsonism is a core feature (with fluctuations and visual hallucinations). |
| Huntington’s disease dementia | Sometimes | Akinetic-rigid “Westphal” variant (esp. juvenile) and later-stage HD can show parkinsonism. |
| Logopenic variant primary progressive aphasia (lvPPA) | Rare/possible | Usually AD pathology; parkinsonism uncommon but can occur with overlap (e.g., LBD/CBS). |
| Multiple system atrophy (MSA) | Core | Defining parkinsonism in MSA-P with autonomic failure; may be minimal in MSA-C. |
| Nonfluent agrammatic PPA (nfaPPA) | Yes (not rare) | Frequently evolves to PSP/CBS phenotypes with axial rigidity, gait freezing, or apraxia of speech. |
| Parkinson’s disease dementia (PDD) | Core | By definition, parkinsonism precedes dementia by ≥ 1 year. |
| Posterior cortical atrophy (PCA) | Rare/possible | Typically AD-related visual syndrome; parkinsonism suggests LBD/CBS overlap. |
| Progressive supranuclear palsy (PSP) | Core | Core atypical parkinsonism with early postural instability/falls, axial rigidity, vertical supranuclear gaze palsy or slow vertical saccades; poor levodopa response. |
| Semantic variant PPA (svPPA) | Rare | Usually TDP-43; parkinsonism is uncommon and typically late/minor if present. |
| Vascular cognitive impairment | Yes | Vascular parkinsonism is a recognised phenotype (lower-body predominant, poor levodopa response). |
