Dementia

Question 1

What is dementia?

Answer 1

-Deterioration of cognitive abilities
-Impairs performance of daily living activities
-Affects memory, intellect, and personality
-Affects 10% of the population >70 yrs old

Question 2

What are the phases of dementia?

Answer 2

Pre-clinical: Initiates years before symptoms present
Prodromal: Mild cognitive impairment, symptoms are present, daily living may not be affected
Dementia: Daily living and function are greatly impacted

Question 3

What are the causes of dementia?

Answer 3

• Alzheimer’s disease >50%
• Vascular: multi-infarct, diffuse white matter
• Parkinson’s disease
• Drug/medications
• Vitamin deficiencies
• Endocrine/organ failure
• Degenerative

Question 4

What is Alzheimer’s?

Answer 4

-Slowly progressive
-diffuse cortical atrophy
-on autopsy: Neurofibrillary tangles, and senile plaques

Question 5

What are SPECT perfusion results of Alzheimer’s?

Answer 5

-Bilateral decrease in perfusion of the temporal and parietal lobes
-Some have a decrease in the entire cortex
-Sensory motor cortex, basal ganglia, thalamus, cerebellum, and occipital areas are spared
-Pattern dependant on progression of disease
+ Early: Posterior cingulate and superior parietal cortex
+ Progressed: Decrease frontal lobe uptake

Question 6

What are SPECT perfusion results of Parkinson’s?

Answer 6

-Same as Alzheimer’s but with occipital lobe involvement
- NM does not play a large role in this pathology

Question 7

What is Lewy body disease?

Answer 7

• Lewy body intracellular inclusions throughout the brain
  -Symptoms: Fluctuating dementia, visual hallucination, falls, parkinsonian symptoms

Question 8

Lewy body diease SPECT perfusion results?

Answer 8

-Occipital lobe and cerebellum uptake
- Involvement of visual centre explain hallucinations
-Posterior cortical region changes
-DaT scan results: Decreased uptake in the basal ganglia

Question 9

What are the clinical signs of Huntington’s disease?

Answer 9

-Movement and cognitive impairment
-uncontrollable movements and episode of choking during eating
-Psychiatric symptoms

Question 10

What are the SPECT perfusion results of Huntington’s disease?

Answer 10

-Decreased rCBF in the heads of the caudate nuclei R > L
- Decreased activity in the right temporal region

Question 11

What is frontotemporal dementia?

Answer 11

-AKA frototemporal lobar degeneration
-more common in younger patients, accounts for half of the patients
-associated with: personality/behavioural changes, decreased initiative, and apathy

Question 12

What are the SPECT perfusion results of frontotemporal dementia?

Answer 12

Decreased perfusion to the frontal lobe and the anterior temporal lobe

Question 13

How do you differentiate Lewy body disease from Alzheimer’s?

Answer 13

-Cingulate island, low occipital uptake, bright outer area in Lewy body
-I-123 Ioflupane (DaT) scan, is used in difficult cases, more sensitive and specific

Question 14

What is multi-infarct dementia?

Answer 14

-Loss of brain function due to a series of mini-strokes
-Blood flow is blocked/interrupted
-Impaired O2 supply: death of brain tissue, cardiac

Question 15

What does Multi-infarct look like in SPECT perfusion?

Answer 15

-Multiple focal asymmetric defects
-Generalized decrease in uptake