Parkinson Disease

PD is a progressive neurodegenerative disorder characterized by bradykinesia, rigidity, resting tremor, and postural instability. Etiology involves genetic and environmental factors. Pathophysiology includes dopaminergic neuronal loss in the substantia nigra pars compacta and alpha-synuclein accumulation. Diagnosis is clinical, supported by neuroimaging and exclusion of mimics. Management includes dopaminergic therapy, deep brain stimulation, and physiotherapy; prognosis is chronic progressive disability with preserved lifespan in most patients.