Section 9 - Diencephalon and Telencephalon

Question 1

Irritative cortical lesions of the frontal eye field make the eyes look ______ the side of lesion.
Destructive cortical lesions of the frontal eye field make the eyes look ______ the side of the lesion.

Answer 1

• Away from

- Toward

Question 2

Lesions to Brodmann area 44,45 (pars opercularis and pars triangularis) produce…

Answer 2

Broca (or expressive) aphasia - difficulty translating thoughts into coherent sentences.

Question 3

Lesions to Brodmann area 22,21 (temporal lobe) produce…

Answer 3

Wernicke (receptive) aphasia - patients cannot understand what they hear, cannot read or write, and speak in a jumble of words that makes no sense

Question 4

Thalamic syndrome is caused by:

Answer 4

Disturbance of thalamic somatosensory portion (from a vascular lesion), involving ventral posterior thalamus.

Question 5

List symptoms of thalamic syndrome.

Answer 5

• Proprioception, pain, temp, touch impaired on CONTRALATERAL side on body
• Pain can be spontaneious, intractable to analgesics
• May be an emotional liability - spontaneous laughing/crying

Question 6

What is amusia?

Answer 6

Aphasia form in which there is an inability to produce/recognize music

Question 7

Damage to basilar nuclei results in…

Answer 7

motor deficits (like involuntary movements)

Question 8

What is auditory agnosia?

Answer 8

Inability to recognize or respond to complex sounds

Question 9

Central pain is theorized to arise from __________

Answer 9

abnormal activity in thalamic or cortical neurons deprived from normal afferent

Question 10

What is Korsakoff’s syndrome?

Answer 10

Amnesia due to degenerative changes in areas surrounding the third ventricle

• Mediodorsal thalamic nucleus
• Mamillothalamic tract/mammillary bodies

Question 11

What is hemiballismus?

Answer 11

Involuntary movements that come on suddenly with great force and rapidity from lesion in CONTRALATERAL subthalamic nucleus. Movements are flailing aimlessly, spontaneous, most severe at proximal joints of limbs (esp. arms). Can involve face mm.

Question 12

Vascular lesions of ______ can cause hemiballismus.

Answer 12

posteromedial branch of PCA or posterior communicating artery

Question 13

What is quatrinopias?

Answer 13

Lesion of the retrolenticular limb of internal capusle. A contralateral quadrant of each eye is lost. (Vision is lost I’m assuming…not a quarter of the actual eyeball).

Question 14

What is a craniopharyngioma?

Answer 14

Rathke pouch tumor - pouch fails to undergo migration and apposition to infundibulum. Tumor mimics pituitary gland –> visual problems, diabetes insipidus, increased intracranial pressure

Question 15

A lesion of the thalamic ventromedial nucleus produces what (bilateral)?

Answer 15

Hyperphagia –> obesity (generally, over-eating)

Question 16

A pinealoma causes what?

Answer 16

Depressed gonadal function, delayed puberty.

Question 17

A lesion of the pinal causes what?

Answer 17

Precocious puberty (pineal secretions inhibit gonadal formation)

Question 18

What is anterior choroidal artery syndrome?

Answer 18

ACA is occluded –> visual and motor deficits reflecting damage to optic tract and inferior portion of posterior limb of internal capsule

Question 19

Vascular lesions of the thalamus can extend into the internal capsule (and vice versa). Strokes in hemisphere can lead to ________

Answer 19

Contralateral hemiparesis and hemianesthesia (corticospinal and thalamocortical fibers)

Question 20

What is Dejerine-Roussy syndrome?

Answer 20

Intense pain following occlusion (such as in thalamogeniculate a.) and subsequent ischemia to the corticospinal/thalamocortical fibers of internal capsule.

(ischemia here causes contralateral hemiparesis and hemianesthesia)

Question 21

What does an insular cortex lesion cause?

Answer 21

Results in diminution or loss of desire to continue addictive behavior.

Question 22

Lesion of the primary visual cortex can cause _______, which is _______.

Answer 22

• Homonymous hemianopia

- Loss of visual input from contralateral half of visual field of each eye (designated right or left hemianopia)

Question 23

Seizure therapy for patients with severe generalized seizures is done by _________

Answer 23

Disconnecting 75% of the corpus callosum (mostly leave splenium).

Question 24

Lesions of the corpus callosum can be caused by:

Answer 24

• Vascular infarct
• Tumor
• Necrosis
• Demyelination

Question 25

The posterior limb of the internal capsule is supplied by:

Answer 25

The anterior choroidal a.

Question 26

The anterior limb of the internal capsule is supplied by:

Answer 26

Lenticulostriate aa. and medial striate a.

Question 27

IC posterior limb ischemia leads to:

Answer 27

Combination of motor/sensory defects contralateral to lesion

Question 28

Damage to retrolenticular limb of IC results in:

Answer 28

Contralateral hemifield (hemianopia) or contralateral quadrant (quadrantopia) visual defects

Question 29

What is a pathological sign of Huntington disease?

Answer 29

Head of caudate nucleus is characteristically diminished in size or absent in MRI/CT

Question 30

Temporal lobe lesion affecting hippocampus and amygdala (esp. bilateral) results in:

Answer 30

• Eating and sexual behavior changes
• Decreased aggression level
• Memory function (loss of recent memories / inability to acquire new ones - distant past remains though)

Question 31

Occluded thalamoperforating aa. (like when clipping basilar aneurysm) can lead to…

Answer 31

A patient that is permanently comatose. Yikes. These perfuse the rostral thalamus.

Question 32

A stroke of the thalamogeniculate a. can lead to…

Answer 32

total sensory loss