(GP) (Mental Health) (Neurology)

Overview

• Acquired disorder of cognitive function

• Most common cause of dementia in the UK is Alzheimer's disease followed by Vascular and Lewy body dementia. These conditions may coexist.

  • Alzheimer’s → degeneration of the cerebral cortex, with cortical atrophy and reduction in acetylcholine production. Build up of APP (due to beta and gamma secretase).
    • Categorised as Mild/Moderate/Severe
  • Vascular → brain damage due to several incidents of cerebrovascular disease (e.g. strokes/TIAs)
  • Lewy Body → deposition of abnormal proteins (Lewy bodies) within the brain stem and neocortex
  • Frontotemporal → specific degeneration of the frontal and temporal lobes. Thought to be caused by pick bodies.

  Alzheimer’s > Vascular > Lewy Body > Frontotemproal

Making Diagnosis

Clinical Features:

• Memory Impairment
• Cognitive Impairment
• Alzheimer’s Disease → slowly progressive, episodic impairment of memory
• Vascular Dementia → abrupt cognitive decline and stepwise deterioration
• Lewy Body Dementia → steady decline, fluctuating levels of consciousness, visual hallucinations and parkinsonian motor disorders
• Frontotemporal Dementia → early changes in personality (eg. Impulsivity, aggressiveness). Often has a family history. Starts slightly earlier than other dementias (50-60).

Depression ⇒ can mimic symptoms of dementia in elderly. Will have shorter history with rapid onset and biological symptoms (eg. sleep disturbance).

Investigations:

• Cognitive Assessment → Mini-Mental State Examination (MMSE, patient who scores 24 points or less is generally considered to have dementia)
  • 24-30 (no cognitive impairment), 18-23 (mild cognitive impairment), 0-17 (severe cognitive impairment)