Case Study: Complex Management of Parkinson Disease Dementia with Behavioral Symptoms
Patient Presentation
Mr. Thompson is a 74-year-old man with a 9-year history of idiopathic Parkinson disease who presents with worsening cognitive and behavioral symptoms over the past 6 months.
Current Medications:
- Levodopa/carbidopa 600 mg/150 mg three times daily
- Rasagiline 1 mg daily
- Amlodipine 5 mg daily (for hypertension)
- Diphenhydramine 25 mg PRN for sleep (uses 3-4 times weekly)
Medical History:
- Parkinson disease (9 years, initially motor-predominant)
- Mild hypertension (well-controlled)
- Obstructive sleep apnea (compliant with CPAP)
- No history of stroke or cardiovascular disease
Current Symptoms:
Cognitive: Progressive memory decline over 6 months, difficulty with executive function, getting lost in familiar places, trouble managing medications independently
Psychiatric: Visual hallucinations (sees children playing in the living room, non-threatening but persistent), mild depressive symptoms with apathy, occasional paranoid ideation that family members are "plotting against him"
Motor: Moderate bradykinesia and rigidity, mild resting tremor, some postural instability, wearing-off phenomena 1-2 hours before next levodopa dose
Sleep: Fragmented sleep despite CPAP, acts out dreams 2-3 nights per week (punching, kicking movements), daytime somnolence
Other: Mild orthostatic hypotension (BP drops from 135/80 to 110/65 on standing), constipation (bowel movement every 3-4 days)
Family Concerns:
His wife reports he is increasingly confused in the evenings, sometimes becomes agitated when she tries to redirect him, and she is exhausted from sleep disruption due to his nocturnal movements. She is concerned about safety given his balance issues and nighttime behaviors.
Physical Examination:
- Alert but mildly confused about date
- UPDRS motor score: 32 (moderate impairment)
- MoCA score: 19/30 (impaired)
- Mild masked facies, reduced arm swing bilaterally
- Cogwheel rigidity in upper extremities
- Postural instability on pull test
- No focal neurological deficits
Laboratory Results:
- Basic metabolic panel: Normal
- CBC: Normal
- TSH: Normal
- Vitamin B12: Normal
- Urinalysis: Negative
Questions for Clinical Decision-Making:
What is the most appropriate diagnostic formulation for this patient's cognitive-behavioral syndrome? 1, 2, 3
Which medication poses the highest risk for worsening his cognitive and psychiatric symptoms and should be discontinued immediately? 2, 3
What is the stepwise approach to managing his visual hallucinations while minimizing motor deterioration? 2, 3, 4
What pharmacological intervention should be initiated first to address both his cognitive decline and potentially help with hallucinations? 2, 3, 4
How should his nocturnal behaviors (likely REM sleep behavior disorder) be managed? 1, 5, 2
What modifications to his Parkinson medications should be considered to reduce psychosis risk while maintaining motor function? 2, 6, 3
What non-pharmacological interventions should be implemented for his sleep-wake cycle disturbances and evening confusion? 7, 5
If his hallucinations persist despite initial interventions and become distressing or dangerous, what is the safest antipsychotic option for this population? 2, 3, 4
What monitoring parameters are essential given his medication regimen and comorbidities? 7, 6
What safety modifications should be recommended at home given his nocturnal behaviors and postural instability? 1
Learning Objectives:
- Recognize Parkinson disease dementia and distinguish it from delirium
- Identify medications that worsen cognition in PD patients
- Understand the unique challenges of managing psychosis in PD (neuroleptic sensitivity)
- Apply evidence-based treatment algorithms for PD dementia
- Manage REM sleep behavior disorder in the context of PD
- Balance motor symptom control with neuropsychiatric side effects
- Implement appropriate safety measures and caregiver support