Parkinson's disease is a neurodegenerative disease currently affecting 10 million people worldwide. It is a disorder of the central nervous system that mainly affects the motor system. The disease is named after doctor James Parkinson, who in 1817 wrote "An Essay on the Shaking Palsy", the first detailed medical essay where the condition was thoroughly explored in six cases.
Parkinson's disease typically develops in people over the age of 60 but it can also be detected earlier, in the so-called young-onset Parkinson's disease. Men are slightly more affected than women but there are no conclusive studies related to this gender unbalance.
Typical symptoms of Parkinson's disease include tremor, stiffness, and slowed movement. In addition, some other symptoms can develop when the disease progresses, such as dementia and sleep, behavioral, sensory, and emotional problems.
Neural degeneration occurs mainly in a small area of the midbrain called substantia nigra. This part of the brain is populated by neurons that release dopamine, a neurotransmitter that allows the brain to control and coordinate voluntary movement.
The cause of Parkinson's disease is still unknown, although it is known that both genetics and environment play a crucial role. One of the molecular hallmarks of the disease is the presence of Lewy bodies in the neurons located in the substantia nigra, which are aggregations of a protein called alpha synuclein.