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Understanding Non-Alzheimer's Dementias

May 13, 2025

Overview of Non-Alzheimer's Dementias

In this lecture, we cover various types of dementias apart from Alzheimer's Disease, focusing on their unique features and treatment considerations.

Types of Dementia

  1. Vascular Dementia

    • Second most common type, ~20% of cases.
    • Caused by repeated strokes leading to ischemic brain damage.
    • Clinical Hallmark: Stepwise decreases in cognitive function (each decrease represents an ischemic event).
    • Imaging: Multiple areas of ischemic damage.
    • Treatment: Cholinesterase inhibitors, memantine; address stroke risk factors.

  2. Dementia with Lewy Bodies (DLB)

    • Third most common type.
    • Characterized by microscopic clumps of alpha-synuclein (Lewy bodies).
    • Symptoms:
      • Visual hallucinations (distinct hallmark).
      • Cognitive deficits (affects attention, concentration, and executive functions more than memory).
      • Neuroleptic sensitivity (avoid antipsychotics).
      • REM Sleep Behavior Disorder (acting out dreams).
      • Earlier onset and rapid progression (symptoms start before 65).
      • Rapid fluctuations in cognition (lucidity and confusion).
      • Parkinsonism (motor deficits like tremor, rigidity).
    • Prognosis: Poor, ~4 years life expectancy post-diagnosis.
    • Treatment: Palliative, medications borrowed from other conditions.

  3. Frontotemporal Dementia (FTD)

    • Degeneration of frontal and temporal lobes.
    • Symptoms (Mnemonic: O-H-D-E-A-R):
      • Obliviousness to social/emotional cues.
      • Hyperorality (putting things in mouth, dietary changes).
      • Disinhibition (inappropriate behavior due to frontal lobe dysfunction).
      • Executive dysfunction (loss of complex planning, learning).
      • Apathy (inertia, lack of goal-directed activity).
      • Repetitive behavior (stereotyped movements or speech).
    • Additional Signs: Upper motor neuron damage, frontal release signs.
    • Prognosis: Poor, 2-10 years post-diagnosis.
    • Treatment: Symptomatic, involves caregiver support, serotonin-boosting medications.

Key Takeaways

  • Different dementias require different management strategies.
  • Recognizing clinical hallmarks aids in differential diagnosis.
  • Treatment focused on managing symptoms and supporting patients and caregivers.

Recommendations

  • Strengthen understanding through clinical cases and practice questions (e.g., from resources like "Memorable Psychiatry").
  • Engage with educational content for continued learning.

Full transcript