From the Guidelines
Sudden confusion and agitation in a patient with Parkinson's disease should prompt immediate evaluation for delirium, infection, and medication side effects, with management addressing the underlying cause and providing supportive care, possibly including low-dose atypical antipsychotics like quetiapine (12.5-25mg) if needed for severe agitation, as recommended by recent guidelines 1. The most recent and highest quality study, published in 2020, emphasizes the importance of addressing reversible causes of anxiety, delirium, and agitation first, and considering benzodiazepines to manage anxiety or agitation 1. When evaluating the patient, consider the following potential causes:
- Medication side effects, particularly anticholinergics, dopaminergic medications (especially if recently adjusted), and benzodiazepines
- Infection, with urinary tract infections and pneumonia being most common
- Metabolic disturbances like electrolyte abnormalities, dehydration, or organ dysfunction
- Cerebrovascular events (stroke, TIA), trauma (particularly subdural hematoma due to falls), and environmental changes or sleep deprivation
- Psychosis related to Parkinson's disease itself, which may present with hallucinations and paranoia Management should prioritize addressing the underlying cause while providing supportive care, including:
- Maintaining a calm environment
- Ensuring proper hydration
- Having familiar people present to help reduce agitation
- Considering low-dose atypical antipsychotics like quetiapine (12.5-25mg) if needed for severe agitation, as typical antipsychotics can worsen parkinsonian symptoms, as noted in earlier studies 1.
From the Research
Causes of Sudden Confusion and Agitation in PD Patients
- Sudden onset of confusion and agitation in patients with Parkinson's disease (PD) can be caused by various factors, including dopaminergic therapy 2.
- Dopaminergic therapy, such as levodopa, can lead to hallucinations, confusion, and worsening of parkinsonian symptoms 2.
- Psychosis and agitation are common difficulties associated with the late stages of PD, and can be precipitated by the use of antiparkinsonian drugs 3.
- The use of antipsychotic drugs, such as clozapine, can improve behavioral problems, but may worsen motor difficulties 3.
- Quetiapine, an atypical antipsychotic, has been shown to be effective in treating drug-induced psychosis in PD patients, with minimal effects on motor function 3, 4.
- Medication errors, such as the withdrawal of antiparkinsonian drugs, can also contribute to confusion and agitation in PD patients 5.
Treatment-Related Factors
- The reduction of Sinemet dosage can lead to improvement in patients with PD who experience sudden onset of confusion and agitation 2.
- Quetiapine has been shown to be a viable alternative to clozapine in PD patients with dopaminergic psychosis and behavioral disturbances 3, 4.
- Low-dose clozapine has been effective in treating levodopa-induced mental disturbances in PD patients, without causing motor deterioration 6.