Parkinson’s is a degenerative disorder of the central nervous system. The motor symptoms of Parkinson’s disease result from the death of dopamine-generating cells in a region of the midbrain. The cause of this cell death is unknown. Early in the course of the disease, the most obvious symptoms are shaking, rigidity, slowness of movement and difficulty walking. Later, depression, thinking and behavioral problems may develop, with dementia commonly occurring in the advanced stages of the disease. Other symptoms include sensory, sleep and emotional problems. Parkinson’s disease is more common in older people, with most cases occurring after the age of 50 and diagnosis of typical cases is mainly based
on symptoms, with tests such as neuro-imaging being used for confirmation.
The most apparent and well-known symptom is tremor most noticeable when the limb is at rest and disappearing with voluntary movement and sleep. Slowness is another characteristic feature associated with difficulties of the movement process, from planning to initiation and finally execution of a movement along with rigidity, stiffness and resistance to limb movement caused by increased muscle tone and excessive and continuous contraction of muscles.
Modern treatments are effective at managing the early motor symptoms of the disease but as the disease progresses and dopaminergic neurons continue to be lost, some of the drugs eventually become ineffective at treating the symptoms. Diet and some forms of rehabilitation have shown some effectiveness at alleviating symptoms. Surgery and deep brain stimulation have been used to reduce motor symptoms in severe cases where drugs are ineffective.