Parkinson's disease

Parkinson's disease
Other names	Idiopathic or primary parkinsonism, hypokinetic rigid syndrome, paralysis agitans, shaking palsy
A. 1880s illustration of Parkinson's disease (PD) B. Mild motor-predominant PD C. Intermediate PD D. Diffuse malignant PD
Specialty	Neurology
Symptoms	Main: Tremor, bradykinesia, rigidity, postural instability (collectively known as parkinsonism) Other: Dysautonomia, depression, anxiety, sleep abnormalities
Complications	Falls, dementia, aspiration pneumonia
Usual onset	Age over 60[1]
Duration	Long-term
Risk factors	Family history, dyspepsia, general anesthesia, pesticide exposure, head injuries
Diagnostic method	Symptomatic, medical imaging
Differential diagnosis	Dementia with Lewy bodies, progressive supranuclear palsy, essential tremor, antipsychotic use,[2] fragile X-associated tremor/ataxia syndrome, Huntington's disease, dopamine-responsive dystonia, Wilson's disease[3]
Prevention	Physical activity, nicotine, caffeine
Treatment	Physical therapy, deep brain stimulation
Medication	L-DOPA, COMT inhibitors, AAAD inhibitors, dopamine agonists, MAO-B inhibitors
Prognosis	Near-normal life expectancy
Frequency	8.5 million (2019)[4]
Named after	James Parkinson

Parkinson's disease (PD), or simply Parkinson's, is a neurodegenerative disease primarily of the central nervous system, affecting both motor and non-motor systems. Symptoms typically develop gradually, with non-motor issues becoming more prevalent as the disease progresses. Common motor symptoms include tremors, bradykinesia (slowness of movement), rigidity, and balance difficulties, collectively termed parkinsonism. In later stages, Parkinson's disease dementia, falls, and neuropsychiatric problems such as sleep abnormalities, psychosis, mood swings, or behavioral changes may arise.

Most cases of Parkinson's disease are sporadic, though contributing factors have been identified. Pathophysiology involves progressive degeneration of nerve cells in the substantia nigra, a midbrain region that provides dopamine to the basal ganglia, a system involved in voluntary motor control. The cause of this cell death is poorly understood but involves the aggregation of alpha-synuclein into Lewy bodies within neurons. Other potential factors involve genetic and environmental influences, medications, lifestyle, and prior health conditions.

Diagnosis is primarily based on signs and symptoms, typically motor-related, identified through neurological examination. Medical imaging techniques like positron emission tomography can support the diagnosis. Parkinson's typically manifests in individuals over 60, with about one percent affected. In those younger than 50, it is termed "early-onset PD".

No cure for Parkinson's is known, and treatment focuses on alleviating symptoms. Initial treatment typically includes L-DOPA, MAO-B inhibitors, or dopamine agonists. As the disease progresses, these medications become less effective and may cause involuntary muscle movements. Diet and rehabilitation therapies can help improve symptoms. Deep brain stimulation is used to manage severe motor symptoms when drugs are ineffective. There is little evidence for treatments addressing non-motor symptoms, such as sleep disturbances and mood instability. Life expectancy for those with PD is near-normal but is decreased for early-onset.