parkinsonisme

Parkinsonism, also called parkinsonisme in some languages, is a clinical syndrome defined by bradykinesia plus at least one of resting tremor, rigidity, or impaired postural reflexes. It can reflect idiopathic Parkinson disease or other conditions causing similar motor features (secondary or atypical parkinsonism).

Core motor features include progressive bradykinesia, a resting tremor, muscular rigidity, and postural instability with a characteristic shuffling gait. Non-motor symptoms such as hyposmia, constipation, sleep disturbances, mood changes, and cognitive impairment are common and may precede motor signs.

Pathophysiology typically involves degeneration of dopaminergic neurons in the substantia nigra pars compacta with reduced striatal dopamine. Lewy bodies containing alpha-synuclein may be present in idiopathic Parkinson disease. Atypical parkinsonism (e.g., MSA, PSP, CBD) has different pathology and often responds less well to dopaminergic therapy.

Common etiologies include idiopathic Parkinson disease; drug-induced parkinsonism (notably D2 antagonists such as certain antipsychotics and metoclopramide); vascular parkinsonism; toxins; and other neurodegenerative disorders.

Diagnosis is primarily clinical, supported by the pattern of progression and, in uncertain cases, by response to dopaminergic therapy or imaging such as dopamine transporter scans to differentiate from other movement disorders.

Treatment is symptomatic and multidisciplinary. Levodopa–carbidopa is the most effective therapy for motor symptoms, with adjuncts such as dopamine agonists, MAO-B inhibitors, and COMT inhibitors. Nonpharmacologic therapies, including physical, occupational, and speech therapy, are important. Deep brain stimulation may be offered to selected patients with advanced disease and motor fluctuations. Parkinsonism is usually progressive; prognosis depends on the underlying cause and comorbidity. Drug-induced parkinsonism may improve after stopping the offending drug.