White matter tracts

Question 1

3 portions of the corpus callosum

Answer 1

genu
splenium
rostrum

Question 2

What is the medical term for surgical transection of the corpus callosum?

Answer 2

corpus callosotomy

Question 3

when would you do a corpus callosotomy

Answer 3

patients with medically refractory epilepsy

Question 4

side effects of corpus callosotomy

Answer 4

Scalp numbness, nausea, feeling tired or depressed, headaches, dysarthria (difficulty speaking), memory problems, aphasia (difficulty finding words), paralysis, weakness, loss of sensation, personality changes, lack of awareness of one side of the body, loss of coordination.

Question 5

what is the fornix?

Answer 5

The fornix is the major white matter outflow tract from the hippocampus, and pathology involving the fornix would be expected to affect memory

Question 6

Why might a mass lesion in the region of the anterior commissure affect episodic memory?

Answer 6

A lesion on the region of the anterior commissure, would push on the fornix, which is the major outflow tract for the hippocampus, which would cause memory loss.

Question 7

Symptoms such as excessive eating/bulimia/obesity suggests involvement of which region?

Answer 7

hypothalamus

Question 8

3 main parts of the basal ganglia?

Answer 8

caudate nucleus
putamen
globus pallidus

Question 9

what does the anterior commisure connect?

Answer 9

temporal and limbic lobe structures

Question 10

What role might the anterior commissure play in a seizure originating in the amygdala?

Answer 10

spread of seizure activity

Question 11

what does the pineal gland lie under?

Answer 11

splenium of the corpus callosum.

Question 12

what does the posterior commissure link?

Answer 12

the pretectal areas on the right and left sides of the midbrain

Question 13

Which visual reflex might be affected by a lesion involving the posterior commissure?

Answer 13

bilateral pupillary light reflex

Question 14

What might be the clinical effects of a focal lesion in the arcuate fasciculus?

Answer 14

conduction aphasia

Question 15

Why is the thalamus sometimes called the ‘gateway’ to the cerebral cortex?

Answer 15

Since most ascending sensory pathways relay in one of its nuclei in order to reach their cortical targets

Question 16

What is a lacunar infarct and what is it usually caused by?

Answer 16

Lacunar infarcts are small infarcts (2–20 mm in diameter) in the deep cerebral white matter, basal ganglia, or pons, presumed to result from the occlusion of a single small perforating artery supplying the subcortical areas of the brain. Commonly due to intrinsic cerebral small arteriolar abnormality.

Question 17

Where in the internal capsule would such an infarct have to be to cause hemiplegia?

Answer 17

posterior limb

Question 18

what blood vessel does the ventral median fissure contain?

Answer 18

anterior spinal artery

Question 19

role of the gracile fasciculus

Answer 19

carries vibration sense/proprioception from the lower limbs.

Question 20

role of the cuneate fascilculus

Answer 20

carries vibration sense/proprioception from the upper limbs

Question 21

what does the posterior column contain

Answer 21

contain the axons of first order sensory neurons

Question 22

What is ataxia and where in the brain might you expect a lesion to cause this?

Answer 22

Ataxia is a degenerative disease of the nervous system. Many symptoms of Ataxia mimic those of being drunk, such as slurred speech, stumbling, falling, and incoordination. Damage to the cerebellum.

Question 23

what sensation does the dorsal column system conduct?

Answer 23

fine touch and proprioception

Question 24

what sensation does the spinothalamic tract conduct

Answer 24

pain and temperature