Psychiatry · Year 3 · from Psychiatry

Case 3: Lewy Body Dementia

Patient Demographics

  • Age: 71 years old
  • Sex: Male
  • Occupation: Retired architect

Chief Complaint

Per wife: "He sees children in our living room who aren't there, and he's been acting out his dreams so violently he fell out of bed."

History of Present Illness

The patient is a 71-year-old man whose wife reports 18 months of progressive cognitive changes, visual hallucinations, and behavioral disturbances. The cognitive symptoms began with difficulty with spatial tasks - he got lost driving, had trouble reading blueprints (his professional expertise), and struggled with the TV remote. Memory problems are present but not as prominent as the spatial difficulties.

The hallucinations began approximately 10 months ago. He sees detailed images of small children playing in the house, often in the evening. He sometimes talks to them and becomes distressed when his wife tells him they're not real. He also reports seeing his deceased brother sitting in a chair. The hallucinations are vivid and fully formed, not vague shapes.

His wife reports dramatic fluctuations in his mental status - some days he's nearly his old self, other days he seems confused and "far away." These fluctuations occur even within the same day.

For several years before cognitive symptoms, his wife noticed he was acting out his dreams - yelling, punching, and kicking in his sleep. He once fell out of bed while "fighting someone" in a dream. She started sleeping in a separate room for safety.

In the past 6 months, she's noticed he moves more slowly, shuffles when he walks, and his handwriting has become small and cramped.

Mental Status Examination

Appearance: Elderly man, masked facial expression, mild tremor at rest

Behavior: Cooperative but slow to respond, stares off at times, attention waxes and wanes during interview

Speech: Hypophonic (soft), slow rate

Mood: "Okay" (impoverished response)

Affect: Flat, limited range

Thought Process: Slow but linear when engaged

Thought Content:

  • Describes visual hallucinations of children in matter-of-fact way
  • Some insight that hallucinations may not be real
  • No paranoid delusions
  • No suicidal ideation

Perceptions: Well-formed visual hallucinations of people (children, deceased relatives), occurring especially in evening

Cognition:

  • Attention: Fluctuates markedly during examination
  • MoCA: 20/30
  • Visuospatial: 0/5 (severely impaired - could not copy cube, very poor clock)
  • Memory: 3/5 (relatively preserved)

Insight: Partial - acknowledges some problems but inconsistent

Judgment: Impaired

Physical/Neurological Examination

Motor Findings:

  • Bradykinesia (slow movements)
  • Cogwheel rigidity bilateral upper extremities
  • Shuffling gait with reduced arm swing
  • Mild resting tremor, left > right
  • Postural instability (positive pull test)

Diagnosis

Major Neurocognitive Disorder with Lewy Bodies, Probable (G31.83 + F02.81)

Core Clinical Features (2 of 3 required for "probable"):

  1. Fluctuating cognition: YES - marked variations in attention and alertness
  2. Recurrent visual hallucinations: YES - detailed, well-formed images of children
  3. REM sleep behavior disorder: YES - dream enactment with violent movements

Supportive Clinical Features:

  • Parkinsonism: Present (bradykinesia, rigidity, tremor, gait changes)
  • Severe neuroleptic sensitivity: Not yet tested (AVOID typical antipsychotics)

Timing Criterion:

  • Dementia developed before parkinsonism became prominent (distinguishes from Parkinson's disease dementia)

Treatment Plan

CRITICAL - Medication Precautions:

  • AVOID typical antipsychotics (haloperidol, etc.) - severe neuroleptic sensitivity can cause life-threatening rigidity, autonomic instability
  • If antipsychotic needed for severe psychosis, only low-dose quetiapine or pimavanserin

Cognitive Symptoms:

  • Donepezil 5 mg at bedtime (cholinesterase inhibitors may help cognition and hallucinations)
  • Titrate to 10 mg in 4-6 weeks

Visual Hallucinations:

  • If not distressing and patient has insight, may not require treatment
  • If distressing: Low-dose quetiapine 12.5-25 mg at bedtime
  • Consider pimavanserin (FDA-approved for Parkinson's psychosis)

REM Sleep Behavior Disorder:

  • Melatonin 3-6 mg at bedtime (first line, well-tolerated)
  • Ensure safe sleep environment (mattress on floor, remove sharp objects)
  • If melatonin insufficient, low-dose clonazepam 0.25-0.5 mg

Parkinsonism:

  • Mild symptoms - no treatment unless functionally limiting
  • If treatment needed, low-dose carbidopa-levodopa (may worsen hallucinations)

Safety:

  • Driving cessation
  • Fall precautions (PT evaluation, remove tripping hazards)
  • Supervision due to fluctuating cognition

Follow-up:

  • Neurology/Movement disorders clinic in 6 weeks
  • Close monitoring for medication side effects
  • Family education about neuroleptic sensitivity - provide letter for medical emergencies

Image Attribution

Image: MRI brain imaging comparing normal aging, Alzheimer's disease with hippocampal atrophy, and vascular dementia with white matter changes. Source: Radiopaedia. Used for educational purposes under Creative Commons license.

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