At what age does Parkinson's disease typically onset?

Parkinson's disease most commonly begins to manifest in individuals around the age of 60, although it can occur earlier in some cases. The neurodegenerative disorder involves the gradual loss of dopaminergic neurons in the substantia nigra region of the brain, which primarily affects motor control.

While there are instances of early-onset Parkinson's, which can occur when symptoms develop before the age of 50, a majority of cases are diagnosed in older adults, particularly those around 60 years and older. Therefore, identifying 55 and later as the onset aligns well with the typical demographic affected by the disease and the average age at diagnosis.

The other options include ages associated with earlier onset that do not reflect the average age range where most Parkinson's cases are diagnosed.