Deterioration of cells in the brainstem, cerebral cortex, cerebellum and basal ganglia — a cluster of cells deep within your brain — is what causes the coordination and movement issues of progressive supranuclear palsy.

The most frequent first symptom of PSP is a loss of balance while walking which can lead to abrupt and unexplained falls. People with PSP may also have stiffness and slow movement. As the disease progresses, most people develop eye problems.

Balance problems and changes in gait are the clearest symptoms that can identify PSP. This is especially true when combined with an inability to control or move the eyes.

In MSA, additional areas of the brain are affected, including the cerebellum, affecting balance and coordination, and the brain stem, affecting autonomic functions, such as blood pressure and bladder function. In PSP, the upper part of the brain, the cortex, is affected, impacting cognitive functions and behaviour.