Neurology · Year 3 · from Neurology

Case 1: Alzheimer's Disease

Patient Demographics

  • Age: 72 years
  • Sex: Female
  • Occupation: Retired school principal

Chief Complaint

Family: "She keeps asking the same questions and got lost driving to church."

History of Present Illness

The patient's family has noticed progressive memory problems over the past 2-3 years. She frequently misplaces items and accuses family members of stealing. She asks the same questions repeatedly, even after just being told the answer. She recently got lost driving to her church of 40 years. She has missed appointments and bill payments. She has difficulty following recipes she has made for decades. She sometimes struggles to find words in conversation. She has become withdrawn from social activities she previously enjoyed. She has preserved motor function and can perform basic self-care. Her husband manages medications as she was taking pills at the wrong times. No hallucinations. No sudden worsening.

Neurological Examination Findings

Mental Status Examination:

  • MMSE Score: 18/30 (mild-moderate impairment)
  • Orientation: 3/10 (lost points for date, day, month, year, floor, county)
  • Registration: 3/3
  • Attention/Calculation: 1/5 (serial 7s)
  • Recall: 0/3 (unable to recall any words at 5 minutes) - key finding
  • Language: 7/9 (anomia for "watch stem")
  • Visuospatial: Cannot copy intersecting pentagons
  • MoCA Score: 14/30
  • Clock drawing: Disorganized, numbers scattered

Cranial Nerves:

  • Intact II-XII
  • No anosmia (unlike Lewy body dementia)

Motor Examination:

  • 5/5 strength throughout
  • Normal tone (no rigidity)
  • No tremor
  • No myoclonus

Sensory Examination:

  • Intact

Reflexes:

  • 2+ symmetric
  • No frontal release signs initially
  • Plantar responses flexor

Coordination:

  • Normal finger-to-nose, heel-to-shin

Gait:

  • Normal base, normal speed
  • No parkinsonian features

Cognitive Domain Assessment

DomainFindingInterpretation
MemoryCannot learn new information, poor recallHippocampal dysfunction - hallmark
ExecutiveImpaired planning, judgmentFrontal involvement
LanguageWord-finding difficulty (anomia)Temporal-parietal
VisuospatialImpaired clock drawingParietal involvement
BehaviorApathy, social withdrawalCommon in AD

Neuro Workup

  • Laboratory Studies (to exclude reversible causes):
  • TSH: Normal
  • B12: Normal
  • CBC, CMP: Normal
  • RPR: Non-reactive
  • HIV: Negative
  • MRI Brain:
  • Bilateral hippocampal atrophy (medial temporal lobe) - characteristic
  • Temporal and parietal cortical atrophy
  • No significant white matter disease
  • No infarcts
  • FDG-PET (if diagnostic uncertainty):
  • Hypometabolism in temporoparietal regions bilaterally
  • Posterior cingulate hypometabolism (early finding)
  • Amyloid PET or CSF biomarkers (if available):
  • CSF: Low Aβ42, elevated tau and p-tau
  • Amyloid PET: Positive (not required for diagnosis)

Diagnosis

Probable Alzheimer's Disease Dementia (NIA-AA criteria 2011)

  • Insidious onset, progressive cognitive decline
  • Amnestic presentation (memory most affected)
  • Impairment in ≥2 cognitive domains
  • Interferes with daily function
  • Not explained by delirium or other conditions

Management

Pharmacological Treatment:

  1. Cholinesterase inhibitor: Donepezil 5 mg daily, increase to 10 mg after 4-6 weeks
  • Alternatives: Rivastigmine, galantamine
  • Modest symptomatic benefit (does not stop progression)
  1. NMDA receptor antagonist: Add memantine 5 mg daily, titrate to 10 mg BID
  • For moderate-severe AD
  • Can combine with cholinesterase inhibitor
  1. Anti-amyloid monoclonal antibodies (newer):
  • Lecanemab, donanemab - for early AD with confirmed amyloid
  • Slows cognitive decline modestly
  • Requires amyloid PET or CSF confirmation
  • Risk of ARIA (amyloid-related imaging abnormalities)

Behavioral Symptom Management:

  1. Agitation/aggression: Non-pharmacological first; if needed, low-dose SSRI, trazodone
  2. Depression: SSRI (sertraline, escitalopram)
  3. Sleep disturbance: Sleep hygiene, low-dose trazodone
  4. Avoid: Anticholinergics, benzodiazepines, typical antipsychotics

Non-Pharmacological Interventions:

  1. Structured daily routine
  2. Cognitive stimulation activities
  3. Physical exercise
  4. Social engagement
  5. Caregiver education and support

Safety Assessment:

  1. Driving evaluation - recommend stopping based on getting lost
  2. Home safety evaluation (stove, firearms, medications)
  3. Medical alert bracelet
  4. Consider tracking devices

Caregiver Support:

  1. Alzheimer's Association resources
  2. Support groups
  3. Respite care
  4. Financial and legal planning (while patient can participate)

Advance Care Planning:

  1. Establish healthcare proxy/durable power of attorney
  2. Discuss goals of care, code status
  3. Consider palliative care as disease progresses

Clinical Image

Image Description: Coronal T1-weighted MRI showing bilateral hippocampal atrophy and enlarged temporal horns of the lateral ventricles, characteristic findings in Alzheimer's disease.

Attribution: Image from Radiopaedia.org, Case courtesy of Dr. Frank Gaillard. Licensed under CC BY-NC-SA 3.0. Source: https://radiopaedia.org/cases/alzheimer-disease-2

All cases for this lecture as Markdown