Parkinson's Disease

Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by the loss of dopamine-producing neurons in the substantia nigra, a region of the midbrain. The decline in dopamine levels leads to the hallmark symptoms of Parkinson's, which include resting tremor, bradykinesia (slowness of movement), rigidity of the limbs and trunk, and postural instability. Non-motor symptoms can also occur, such as cognitive impairment, mood disorders, sleep disturbances, and autonomic dysfunction. The pathophysiology of PD involves not only dopamine deficiency but also the accumulation of abnormal protein aggregates known as Lewy bodies within neurons, contributing to cellular dysfunction and death.

Diagnosis of PD is primarily clinical, based on medical history and neurological examination, as there is no definitive diagnostic test. The Unified Parkinson's Disease Rating Scale (UPDRS) is commonly used to assess the severity of symptoms. Treatment is symptomatic, with levodopa being the cornerstone therapy to replace dopamine. Other medications, such as dopamine agonists and MAO-B inhibitors, are used as adjunctive therapies. Advanced cases may benefit from surgical interventions like deep brain stimulation. Although there is currently no cure, research continues to focus on neuroprotective strategies and identifying disease-modifying treatments that can slow the progression of PD.