Limbic Cortex

Question 1

Hippocampal lesion prevents the conversion to memories resulting in _________

Answer 1

anterograde amnesia

Question 2

Bilateral hippocampal formation lesion seen in _____________

Answer 2

heart attack, near downing, severe hypoglycemia, or cerebral ischemia

Question 3

What is the most vulnerable location in the hippocampal formation to anoxia?

Answer 3

CA1 (Sommer sector, in pathologic conditions)

Question 4

Alzheimer disease (AD) is characterized by…

Answer 4

Presence of neurofibrillary tangles, neuritis plaques, and specific brain region neuronal loss

Question 5

In AD, what are the first places affected?

Answer 5

Subiculum and entorhinal cortex –> impede relay of information through hippocampus

Question 6

What is declarative memory loss?

Answer 6

Poor recall or incorporation of new memories

Divided into semantic and episodic memory (fact/concepts, events/experiences)

Question 7

AD progresses to …

Answer 7

long-term memory impairment and behavioral changes

Question 8

Why is the procedural or implicit memory spared in AD?

Answer 8

(motor skills for performing tasks)

Basal ganglia and cerebellum are spared

Question 9

Prolong thiamine deficiency is often seen in cases of…

Korsakoff psychosis

Answer 9

chronic alcoholism, cancer cachexia, or any prolonged state of malnutrition; causes a characteristic pattern of degeneration

• degradation of mammillary bodies, dorsomedial nucleus of the thalamus, and the columns of the fornix
• also a loss of neurons in the hippocampal formation

Question 10

Symptoms of Korsakoff psychosis (alcoholic dementia) are:

Answer 10

• defect in short-term memory and consequently also in long-term memory for events occurring since the onset of the disease
• anterograde and retrograde amnesia
• appear demented
• prone to confabulation

This is IRREVERSIBLE

Question 11

What is Wernicke encephalopathy?

Answer 11

An acute thiamine deficiency
- triad of eye movement abnormalities (ophthalmoplegia), ataxia, and confusion

REVERSIBLE with thiamine administration

Question 12

What is Wernicke-Korsakoff syndrome?

Answer 12

A severe case where patients may present with the Wernicke triad accompanied by profound memory loss

Question 13

Which nucleus is associated with addiction?

Answer 13

Nucleus accumbens

Question 14

Aversion center stimulation –>

Answer 14

Fear, sorrow

Question 15

Gratification center stimuation –>

Answer 15

Pleasure

Question 16

The hippocampus and amygdala have an abundance of _______; the nucleus accumbens has an abundance of _______

Answer 16

aversion centers; gratification centers

Question 17

Large lesions in the amygdala, hippocampus, fornix, or cingulate or prefrontal cortex lead to… (very generally)

Answer 17

flattening of emotions (as reflected by the fact that emotional extremes, like joy and anxiety are reduced)
- due to the loss of both aversion and gratification centers

Question 18

Bilateral lesion to the anterior part of the cingulate gyrus causes…

Answer 18

Akinetic mutism; diminished emotional responses of patient

- potentially leading to immobility, muteness, and unresponsiveness (but NOT in coma)

Question 19

Some people with cingulate damage may be alert but …

Answer 19

with no idea who they are or be unable to recall order of past events; may also be unable to recall the order in which past events occurred

Question 20

What is Kluver-Bucy Syndrome?

Answer 20

Bilateral temporal lobe lesion (specifically amygdaloid complex)

Question 21

Symptoms of Kluver-Bucy Sydrome?

Answer 21

• memory deficit (from lesion to BOTH hippocampus and amygdala)
• visual agnosia
• possibly tactile/auditory agnosia
• hyperorality (tendency to examine objects excessively by mouth) or smell objects
• hypermetamorphosis (compulsion to intensively explore the immediate environment)
• overreaction to visual stimuli
• placidity (no longer show fear/anger)
• hyperphagia (eat excessively, or objects that are not food)
• hypersexuality
• additional symptoms are amnesia, dementia, aphasia (all depending on the extent of temporal lobe damage)

Question 22

What is the most common cause for complex partial seizures?

Answer 22

Damage to mesial temporal lobe (mesial temporal sclerosis)

Question 23

What is a complex partial seizure?

Answer 23

Seizure that starts in a specific area of the brain, resulting in a wide range of physical and emotional behaviors with alteration of consciousness. Partial seizures are often associated with a warning or an aura.

Question 24

Seizures starting in the uncus may be associated with uncinate fits, which are:

Answer 24

olfactory or gustatory hallucinations

Question 25

Seizures starting in areas of the limbic system may be associated with:

Answer 25

• uncinate fits
• visual illusions
• sensations of impending doom
• déjà vu (unfamiliar seems familiar),
• jamais vu (familiar seems unfamiliar)
• autonomic disturbances

Question 26

Temporal lobes can be damaged by:

Answer 26

HSV encephalitis, trauma, hypoxia

Question 27

Some symptoms of HSV encephalitis?

Answer 27

high fever, confusion, personality changes, seizures; hemorrhage/necrosis of temporal lobes –> inability to form new memories

Question 28

What is epilepsy?

Answer 28

Recurrent seizure activity

Related to malfunction of hippocampus

Question 29

_____ is most resistant to seizure activity, _____ are most vulnerable

Answer 29

CA2; CA4 and Sommer sector

Question 30

Poorly-controlled seizures can lead to…

Answer 30

memory impairment and emotional problems

Question 31

Layers in the dentate gyrus:

Answer 31

granular, polymorphic, molecular

Question 32

Layers in the rest of the hippocampus:

Answer 32

polymorphic, pyramidal, molecular

Question 33

What is a Duchenne versus Pyramidal smile?

Answer 33

Smiling muscles affected by limbic system vs. the voluntary pyramidal tract