There are several degenerative conditions that cause parkinsonism but are distinct from Parkinson’s disease. They typically deteriorate more quickly and tend to be resistant to treatments for PD. They can be hard to diagnose clinically and are often identified pathologically at post mortem.
Multiple System Atrophy
- Characterised by parkinsonism, autonomic failure and cerebellar symptoms
- Usually either parkinsonism of cerebellar features predominant (MSA-P or MSA-C, respectively)
- Rare (~4/100,000 prevalence)
- Characterised pathologically by α-synuclein inclusions in glial cells in the basal ganglia, cerebellum and motor cortex
- May be differentiated from PD by early onset falls, postural instability and lack of response to levodopa.
- Mean survival is <10 years and management is symptomatic; disability occurs early; cognition is preserved.
Progressive Supranuclear Palsy
- Similar prevalence and survival as MSA.
- Presents as symmetrical parkinsonism, cognitive impairment, early falls and bulbar symptoms
- characteristic eye movement impairment- slow vertical saccades (impaired up/down gaze) can take years to manifest
- Pathologically characterised by abnormal accumulation of tau proteins and degeneration of the substantia nigra, subthalamic nucleus and mid-brain.
- It does not respond to levodopa and there is no treatment available.
- Less common than MSA or PSP
- Clinical presentation is variable
- Parkinsonism, dystonia, myoclonus and ‘alien limb’; discoordination/apraxia; dementia
- Tauopathy with widespread deposition throughout the brain
- Similar survival to other PPSs