Chapter 6

Question 1

Name the main risk factors for Alzheimer’s Disease.

Answer 1

Age, Apolipoprotein E4, head trauma (either once severe, or several light traumata), cardiovascular disease, genes (AD or Down’s syndrome), extrapyramidal signs, hypothyroidism, Sex (being female), low education

Question 2

The Apolipoprotein E4 is a large risk factor for AD. However, for a subgroup of people this is not the case. Which subgroup is meant?

Answer 2

People with depression who underwent electroconvulsive therapy.

Question 3

What characterizes the neuropathology in AD? Where does it take place?

Answer 3

In AD there is mainly atrophy instead of cell death. Shrinkage can be found in basically all cortical parts of the brain (frontal, temporal, parietal, occipital, hippocampus). Subcortical neuropathology can be found in the basal forebrain, locus coeruleus, dorsal raphe nucleus and in the pedunculopontine tegmental nucleus (ARAS).

Question 4

In how far is the metabolism affected in AD?

Answer 4

There is a reduced metabolism, characterized by deterioration of mitochondrial enzyme activity.

Question 5

Which pathways are primarily affected in AD?

Answer 5

Frontostriatal, frontocerebellar, frontohippocampal and nigrostriatal circuits.

Question 6

In AD there are … neuritic amyloid plaques and … neurofibrillary tangles found.

Answer 6

(1) extracellular (2) intraneuronal

Question 7

Describe the neuropathological development in AD.

Answer 7

Tangles found in entorhinal cortex in initial stage. Later these tangles spread to the hippocampus and all other parts of the cortex, except for the primary sensorimotor cortices. In the final stage, neuropathological tangles are also found in subcortical areas (e.g striatum, thalamus and hypothalamus).

Question 8

Describe the amyloid cascade hypothesis.

Answer 8

Amyloid plaques become neuritic plaques by an inflammatory process. Neuritic plaques constitute neurofibrillary tangles which are neurotoxic and lead to cell death.

Question 9

Name the main symptoms in AD.

Answer 9

Executive dysfunctions (e.g. planning, category fluency, attention, working memory, abstract thinking and concept formation), disturbances in episodic (retrograde and anterograde amnesia) and semantic memory, visuospatial dysfunctions, motor- (ideomotor apraxia) and speech problems, behavioural disturbances (e.g apathy, depression, anxiety, aggression, …).

Question 10

Which type of learning is generally preserved in AD? What is the reason for this?

Answer 10

Procedural learning is generally preserved. This is due to less severe frontostriatal damage.