RESUMO
Delirium is an acute and fluctuating disturbance of attention and awareness. Pre-existing cognitive disturbances or dementia are the most significant risk factors for developing delirium and precipitating factors such as drug treatment, infections, trauma, or surgery may trigger delirium. Patients with Parkinson's disease (PD) are at an increased risk for delirium which may be underdiagnosed due to phenomenological overlap between delirium and chronic neuropsychiatric features of PD or side effects of dopaminergic medication. Prognosis of delirium is detrimental in many cases including permanent cognitive decline, motor impairment, and increased mortality. Management of delirium comprises of pharmacological and non-pharmacological measures. Pharmacotherapy is aimed at treating medical precipitating factors such as infections, pain, and sleep deprivation. Adjustments of anti-parkinsonian medication are recommended to prevent or treat delirium, but no hard evidence in this respect is available from controlled studies. Administration of neuroleptics and other psychoactive drugs in the treatment of delirium is controversially discussed and should be reserved for patients with severe agitation or distressing psychosis. Non-pharmacological interventions to prevent or palliate delirium are based on withdrawing precipitating or distressing factors, and to provide sensory, emotional and environmental support. Appropriate instruments to detect and assess delirium in PD are needed, and efforts are warranted to improve understanding and treatment of this severe and common disorder.