Neuroscience · Year 2 · from Neuroscience
Case 1: Alzheimer's Disease
Patient Presentation
Demographics: 74-year-old male
Chief Complaint: Memory problems and getting lost while driving (brought by wife)
History of Present Illness: The patient's wife reports that over the past 2-3 years, her husband has had gradually worsening memory problems. Initially, he began misplacing items and forgetting recent conversations. Over the past year, this has progressed significantly. He forgot their granddaughter's birthday party that happened last week but remembers details from their wedding 50 years ago. He got lost driving to their church, which they have attended for 30 years. He has asked the same questions repeatedly and has difficulty managing their finances, which she has now taken over. He has become more withdrawn and less interested in his hobbies. The patient minimizes his symptoms, saying "my memory is fine for my age."
Family History: Mother had "dementia" in her 80s
Physical Examination:
- Vital signs: Normal
- General: Pleasant, well-groomed male who defers questions to wife
- Neurological:
- Mental status: Alert; oriented to person and city but not date (says "sometime in spring" when it's October); poor recall of recent events
- Montreal Cognitive Assessment (MoCA): 18/30 (impaired in delayed recall 0/5, orientation 4/6, abstraction, and clock drawing)
- Language: Mild word-finding difficulty; circumlocution; comprehension intact
- Cranial nerves: Intact
- Motor: 5/5 throughout; no parkinsonism
- Sensory: Intact
- Reflexes: 2+ symmetric; frontal release signs (palmomental reflex present)
- Gait: Normal
Workup:
- MRI brain: Bilateral hippocampal atrophy (more prominent than expected for age); moderate generalized cortical atrophy; no vascular changes; Fazekas grade 1 white matter changes
- Laboratory: TSH normal; B12 normal; RPR negative; CBC, CMP normal
- Amyloid PET: Positive (diffuse cortical amyloid deposition)
- CSF (optional, obtained for confirmation): Decreased A-beta 42, increased phospho-tau, increased total tau - consistent with Alzheimer's pathology
Diagnosis: Alzheimer's disease dementia, moderate stage (NIA-AA criteria)
Treatment:
- Donepezil 5 mg daily, increased to 10 mg after 4-6 weeks (cholinesterase inhibitor)
- Memantine to be added when disease progresses to moderate-severe stage
- Discussed newer anti-amyloid therapies (lecanemab); patient not a candidate due to moderate stage (most effective in early disease)
- Driving evaluation recommended; advised to stop driving given getting lost
- Safety assessment: removed firearms from home; stove knob covers installed
- Caregiver support resources provided to wife
- Advanced care planning discussion
Clinical Course: At 6-month follow-up, the patient's wife reported some stabilization in his memory with donepezil, though mild GI side effects initially. He accepted not driving after the formal driving evaluation recommended against it. His wife joined a caregiver support group. The family completed healthcare proxy and advance directive documentation while the patient could still participate in discussions.
Clinical Pearl: Alzheimer's disease is characterized by insidious onset and gradual progression, with memory impairment (especially for recent events) as the earliest and most prominent feature. Patients often have limited insight (anosognosia). The pattern of better remote memory with impaired recent memory reflects hippocampal involvement in encoding new memories while consolidated long-term memories are stored elsewhere. Biomarkers (amyloid PET, CSF A-beta/tau) now allow definitive diagnosis during life. Disease-modifying therapies (anti-amyloid antibodies) are most effective when started early.