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.