Parkinsonism is a clinical syndrome characterized by the presence of some or all of the following features; there is overlap with so-called akinetic-rigid syndromes in which these features predominate:

Akinesia, hypokinesia (sine qua non)
Rigidity: consistent (lead-pipe) or jerky (cogwheeling; Negro’s sign)
Tremor, usually at rest, of frequency 3.5-7.0 Hz, "pill rolling" type; there may sometimes be an additional action component to the tremor, and very occasionally there is exclusively an action tremor
Stooped posture: forward flexion of trunk, flexion of knees, elbows; "simian posture"

Impaired postural reflexes, with or without a history of falls; propulsion, retropulsion
Mask-like facies, poverty of facial expression (hypomimia)
Reduced blink rate (this may be a particular feature of progressive supranuclear palsy)
Hypophonic, monotonic voice (hypokinetic dysarthria) Widened palpebral fissure (Stellwag’s sign) Hypometria
Seborrhea Sialorrhea
Festinant (shuffling) gait Micrographia
Dystonic postures, for example, striatal toe Apraxia
Cognitive impairment (usually of frontal-subcortical type) Hallucinations: minor (anwesenheit; passage type), or formed,
visual > auditory
Autonomic dysfunction, especially Orthostatic hypotension

Conventionally parkinsonism is viewed as a disorder of the extrapyramidal system producing "extrapyramidal signs", although this term has limitations: despite the fact that some of the cardinal features of parkinsonism (bradykinesia, rigidity, postural instability, tremor) result from pathology in the basal ganglia, particularly affecting dopaminergic pathways, other features may reflect cortical involvement, at least in part (e.g., apraxia, micrographia).
The incidence of parkinsonism increases dramatically with age; it is also associated with an increased risk of death, particularly in the presence of a gait disturbance.
The differential diagnosis of parkinsonism is broad, and includes:

Idiopathic Parkinson’s disease Multiple system atrophy
Progressive supranuclear palsy (Steele-Richardson-Olszewski syndrome)
Corticobasal degeneration, cortical basal ganglionic degeneration Drug-induced parkinsonism (e.g., neuroleptics, MPTP)
Toxin-induced parkinsonism (e.g., carbon monoxide, manganese) Wilson’s disease (hepatolenticular degeneration)
Dementia with Lewy bodies Neuroleptic malignant syndrome Normal pressure hydrocephalus
"Arteriosclerotic parkinsonism", resulting from multiple subcortical infarcts
Huntington’s disease, especially juvenile onset (Westphal variant) Post-encephalitic parkinsonism (encephalitis lethargica, von
Economo’s disease)
Dementia pugilistica, post-traumatic parkinsonism Systemic lupus erythematosus

Sjögren’s syndrome Hypoparathyroidism
Parkinsonism-dementia complex of Guam

Obsessive slowness also enters the differential diagnosis but typical parkinsonian features (akinesia, rigidity) are not present in this condition.
It is crucial not to miss the diagnosis of Wilson’s disease, although rare, since in the early stages this disorder is reversible with copper chelation therapy; hence copper and ceruloplasmin should be checked in all patients with young-onset (under age 50) parkinsonism (and dystonia).
Response to levodopa therapy is only reliably seen in idiopathic Parkinson’s disease, although some patients with multiple system atrophy or progressive supranuclear palsy may benefit. The features particularly responsive in Parkinson’s disease are bradykinesia and rigidity; tremor is less reliably helped.



Bennett DA, Beckett LA, Murray AM, et al. Prevalence of parkinsonian signs and associated mortality in a community population of older people. New England Journal of Medicine 1996; 334: 71-76
Bhatia K, Brooks DJ, Burn DJ et al. Guidelines for the management of Parkinson’s disease. The Parkinson’s Disease Consensus Working Group. Hospital Medicine 1998; 59: 469-480
Gardner-Thorpe C. James Parkinson 1755-1824. Exeter: A Wheaton & Co. Ltd, 1987 [includes facsimile of Parkinson’s book on the shaking palsy]
Litvan I, Agid Y, Calne D, et al. Clinical research criteria for the diagnosis of progressive supranuclear palsy (Steele-Richardson-Olszewski syndrome): report of the NINDS-SPSP international workshop. Neurology 1996; 47: 1-9
Oertel WH, Quinn NP. Parkinsonism. In: Brandt T, Caplan LR, Dichgans J, Diener HC, Kennard C (eds.). Neurological disorders:course and treatment. San Diego: Academic Press, 1996: 715-772


Cross References

Apraxia; Bradykinesia; Dysarthria; Dystonia; Hypokinesia; Hypomimia; Hypophonia; Mask-like facies; Micrographia; Orthostatic hypotension; Postural reflexes; Rigidity; Seborrhea; Sialorrhea; Striatal toe; Supranuclear gaze palsy; Tremor