Cognitive and Behavioral Neurology

Question 1

Does mild cognitive impairment affect the ability to perform ADLs?

Answer 1

No, this is part of the definition of MCI. There is a 10-15% conversion rate of MCI into dementia per year, which occurs when ADLs start to be affected.

Question 2

List 8 risk factors for Alzheimer’s disease.

Answer 2

Age, female gender, low education level, repeated head trauma, family history of dementia, smoking, vascular risk factors, apolipoprotein E4 genotype

Question 3

List three genes associated with early-onset inherited Alzheimer’s. Which chromosome is each on?

Answer 3

Presenilin 1 on chromosome 14
Presenilin 2 on chromosome 1
Amyloid precursor protein on chromosome 21 (why people with Trisomy 21 have early onset Alzheimer’s).

Question 4

What is transient global amnesia?

Answer 4

Impairment of recent semantic and episodic memory (while immediate memory is intact). Lasts 12-24 hours and resolves without deficit. Associated with migraine, HTN, medical procedures, and stressful events.

Question 5

What might be seen in the CSF profile of a patient with Alzheimer’s disease?

Answer 5

Reduced amyloid, increased tau

Question 6

Atrophy (on MRI) or hypometabolism (on PET) of the bilateral parietotemporal regions is most commonly seen in which dementia?

Answer 6

Alzheimer’s disease

Question 7

Loss of cholinergic neurons in which brain structure is frequently seen in Alzheimer’s disease?

Answer 7

Nucleus basalis of Meynert

Question 8

What is the most common genetic linkage for frontotemporal dementia?

Answer 8

Chromosome 17q21

Question 9

What is one way to distinguish frontotemporal dementia from Alzheimer’s disease?

Answer 9

In Alzheimer’s, the primary complaint is memory loss. In FTD cognitive decline occurs but memory impairment is not the most prominent feature.

Question 10

What is the mechanism of action of donepezil? In what disease is it used?

Answer 10

Pure acetylcholinesterase inhibitor. Alzheimer’s.

Question 11

What is Kluver-Bucy syndrome? Where does it localize?

Answer 11

KB syndrome can be caused by lesions to the bilateral temporal lobes/amygdala. Characterized by hyperorality, preoccupation with minute environmental stimuli, blunted emotional affect, hyper sexuality, visual agnosia, and hypokinesia. Can be seen in Pick’s disease, sequelae of HSV encephalitis, anoxic injury to temporal lobes, historically after bilateral temporal lobectomy.

Question 12

What is Charles Bonnet syndrome?

Answer 12

Vivid hallucinations that occur in people with severe visual impairment. People know that they are hallucinations.

Question 13

What is Anton’s syndrome?

Answer 13

Cortical blindness with denial of visual loss and confabulation. Localizes to bilateral lesions of the medial occipital lobes.

Question 14

What is Balint’s syndrome?

Answer 14

Triad of optic ataxia (deficit of reaching for objects under visual guidance), oculomotor apraxia (inability to move the eyes to a new point of fixation), and simultanagnosia (inability to perceive more than one object at a time). Localizes to bilateral parieto-occipital regions - such as with watershed injury, PML, can also be seen in neurodegenerative diseases. Balint = bilateral.

Question 15

Associate the following classic MRI findings with the appropriate disease:
Cortical ribbon sign
Hippocampal lumpy bumpy sign
Thinning of caudate head
Calcification of the basal ganglia
Eye of the tiger (basal ganglia)

Answer 15

Cortical ribbon sign = CJD
Hippocampal lumpy bumpy sign = Alzheimer’s
Thinning of caudate head = Huntington’s
Calcification of the basal ganglia = Fahr’s disease
Eye of the tiger (basal ganglia) = PKAN (neuronal degeneration with brain iron accumulation)