Part 3: Degenerative Neurocognitive Disorders

What does dementia fall under?

• MCI or MND

Dementia term type

Umbrella

Dementia description

• Severe cognitive decline more so than expected in normal ageing

Dementia + the brain (1→3)

• Reduction in:

  • Grey matter

  • Structural connectivity

  • Functional connectivity

Dementia diagnostic criteria (2)

• Memory impairment AND decline in at least one other cognitive domain from baseline (more than 3SD below mean)

AND

• Functional impairment

Cognitive features that decline with normal ageing (4)

Decline in

• Processing speed

• Complex attention

• Memory

• Exec. function

Dementia sub-types (2) w/ brief description

• Degenerative: slow, permanent breakdown (e.g. Alzheimer’s)

• Non-degenerative: specific events/external factors (e.g. vascular dementia)

Note on rate and trajectory of decline in dementia

• Very individual, depending on

  • Cognitive reserve

  • Access to healthcare

  • Education

Parkinson’s cause (1)

• Degeneration of dopamine producing cells in substantia nigra → reduced dopamine in striatum

Symptom types (2)

• Positive

• Negative

Positive symptoms (3)

• Tremors (alternating movements) at rest (not active movement) → “pill-rolling”

• Muscular rigidity

• Akathesia - involuntary movements

Negative symptoms (5)

1. Posture disorder (head drop)

2. Righting disorder (standing/rolling over)

3. Locomotion disorder (shuffling gait)

4. Speech disturbance - loss of prosody

5. Hypokinesia - diminished motor activity (slow movement, flat expression)

What causes Parkinson’s?

• Very much genetically determined