Subcortical Dementias

Question 1

Subcortical Dementia

Answer 1

Preferentially targets subcortical regions of the brain.

Question 2

Huntington’s Disease

Answer 2

An autosomal dominant condition with a genetic cause characterised by chorea (involuntary, spasmodic and painful movements. Average onset between 30 and 40.

Question 3

Neuropathology of HD

Answer 3

The gene is expressed and causes deterioration of the caudate nucleus, white matter structures and cerebellum.

Question 4

Caudate Nucleus and HD

Answer 4

Part of the basal ganglia. Involved in sequencing, ordering and timing movement.

Question 5

Neuropsychology of HD

Answer 5

Eye movement disturbances, decreased attention, progressive STM deficits, impaired behaviour regulation, sexual promiscuity, mania, depression, irritability, aggression, suicide.

Question 6

Multiple Sclerosis

Answer 6

Destroys the myelin which coats the axons of neurons in the CNS. Average onset around 30 years. No known cause, but vitamin D deficiency is implicated.

Question 7

Neuropsychology of MS

Answer 7

Weakness of limbs, loss of eye muscle control, numbness, fatigue, incontinence, impaired attention and recall, problems with speech production.

Question 8

Parkinson’s Disease

Answer 8

Progressive motor deterioration as a result of a loss of dopaminergic neurons from the substantia nigra. Does not always develop into a dementia.

Question 9

Neuropathology of PD

Answer 9

Lewy bodies found in dying cells. Substantia nigra connects spinal cord and basal ganglia to produce smooth movement. PD destroys the neurons that do this resulting in non-smooth movement.

Question 10

Neuropsychology of PD

Answer 10

Resting tremor, shaking, motor slowing, loss of fine coordination, rigidity, difficulty switching between mental tasks, slowed information processing which leads to attention and memory deficits.

Question 11

AIDS Dementia

Answer 11

Occurs when HIV progresses into AIDS and a lack of immune system allows infections, tumours or the AIDS virus to cross the blood brain barrier and enter the brain.

Question 12

Stages of HIV/AIDS

Answer 12

No cognitive changes during the HIV stage. Early AIDS associated with confusion, motor slowing and mild attention deficits. AIDS dementia can occur 2 days to 2 months post AIDS and causes confusion, disinhibition, mutism, coma and death.

Question 13

Creutzfeldt-Jakob Disease

Answer 13

Extremely rare. Transmitted by consumption of tainted meat/neural tissue, transplants of neural tissue and medical procedures involving infected people.

Question 14

Spongiform Encephalopathy

Answer 14

Sponge like holes form in the brain as a result of CJD (or scapie in sheep of mad cow disease in cows).

Question 15

Neuropathology of CJD

Answer 15

Infectious agent but causes no symptoms of infection. Produces holes in the brain. May be due to scapie-associated fibrils.

Question 16

Scapie-associated Fibrils

Answer 16

Twisted stick like fibres found in the neurons of sheep with scapie and also individuals with CJD. Too small to be recognised by the immune system (hence no infection).

Question 17

Neuropsychology of CJD

Answer 17

Uncoordinated movements, inability to swallow, mood disorders, attention and concentration deficits.

Question 18

Multiple Infarct Dementia

Answer 18

Results from multiple infarctions to brain tissue, usually resulting from repeated ischemic strokes.

Question 19

Neuropsychology of MID

Answer 19

Stepwise onset (stable, worsen, stable etc). Symptoms associated with the location of the infarcts. Individuals tend to have insight and better memory that those with DAT. Tend to have impaired executive functions due to frontal lobe damage (more likely to have an infarct here because of its size).

Question 20

Pallidotomy

Answer 20

Lesion to the globus pallidus to resolve movement problems associated with Parkinson’s. Globus pallidus becomes over active which results in bradykinesia. Risk of memory deficits and confusion

Question 21

Thalomotomy

Answer 21

Lesion to parts of the thalamus to resolve tremors associated with Parkinson’s. Risk of speech dysfunction