White Matter

Question 1

Arcuate fasciculus

Answer 1

Language pathway, connecting temporal, parietal and inferior frontal lobes, linking the receptive Wernicke’s and the expressive Broca’s speech centers

Question 2

Uncinate fasciculus

Answer 2

Connecting mesial temporal structures within the orbitofrontal cortex and frontal pole

Question 3

Superior longitudinal fasciculus

Answer 3

Major fronto-parietal connection, visuospatial, reaching grasping, SLF I, II and III

Question 4

Inferior longitudinal fasciculus

Answer 4

Connects the temporal and occipital lobes merges with the inferior fronto-occipital fasciculus (IFOF)

Question 5

Inferior fronto-occipital fasciculus

Answer 5

Longest association tract . Frontal lobe to occipital lobe

Question 6

Frontal aslant tract

Answer 6

Inferior frontal gyrus (lateral) to the pre-supplementary and supplementary motor areas of the Superior frontal gurys (medial).

Question 7

What is the role of commissural fibers?

Answer 7

Cross midline to connect the two cerebral hemispheres

Question 8

Name the main commissural fibers

Answer 8

Corpus callosum
Anterior Commissure
Hippocampal commissure
Posterior commisure

Question 9

Name the parts of the Corpus Callosum from anteriorly to posteriorly

Answer 9

Rostrum, genu, body, isthmus, splenium

Question 10

What is the lamina terminalis ?

Answer 10

The most rostral aspect of the early neural tube and anterior neuropore

Question 11

What does the line of Talairach-Tournoux connect?

Answer 11

A line through AC-PC

Question 12

What are the three types of white matter fibers?

Answer 12

1. Projection fibers (ascending or descending)
2. Commisural fibers (corpus callosum)
3. Association fibers (connecting cortex of the same hemisphere)

Question 13

In a FA/direction DTI map which fibers are blue, green and red?

Answer 13

Blue = foot to head
Red = Right to left 
Green = Anterior to posterior

Question 14

Which tracts make up the Pyramidal tract?

Answer 14

Corticospinal tract (muscles of the body)
Corticobulbar tract (muscles of the head)

Question 15

Name the projection tracks

Answer 15

• Pyramidal tract
• Corticopontine tract
• Brainstem tract (medial lemniscus)
• Optic radiation

Question 16

Corticobulbar tract

Answer 16

Fibers from the lateral frontal lobe (motor cortex), go to the brainstem where the innervate the nuclei of the cranial nerves. All bilateral innervation except facial and hypoglossal nerves unilatera!

Question 17

Describe connection of Optic radiation

Answer 17

Lateral geniculate nucleus to the primary visual cortex (geniculocalcarine tract)

Question 18

Name a complication of temporal lobe Epilepsy surgery

Answer 18

Post-operative visual field defects in 50-100%

Question 19

Name the parts of the optic radiation

Answer 19

Posterior, central and anterior bundles

Question 20

what is the Meyer’s loop?

Answer 20

Part of the anterior bundle of the optic radiation which curves around the temporal horn

Question 21

Does DTI show lateral fibers of the corpus callosum?

Answer 21

No DTI , can only show medial fibers

Question 22

In anterior or posterior callosal disconnection the symptoms can be often subclinical?

Answer 22

Anterior (genu, ant body)

Question 23

What functions are projected more posteriorly in the corpus callosum?

Answer 23

Auditory and visual

Question 24

Which association tracts are associated with language ?

Answer 24

SLF/Arcuate fasciculus
Uncinate Fasciculus
Inferior fronto-occipital fasciculus
Frontal Aslant Tract

Question 25

what is the safe distance between a tract and a tumour on DTI?

Answer 25

>1cm. If the tract is less than 1cm away from the tumour then needs electrical stimulation

Question 26

Operative electrical stimulation (mapping )or DTI is more accurate?

Answer 26

Operative mapping is the gold standard

Question 27

Depending on the location what will a lesion cause | if in Broca's area? Wernicke's area? Arcuate fasciculus?

Answer 27

Broca's: Expressive aphasia Wernicke's :Receptive aphasia AF: Conduction aphasia

Question 28

Isotropic diffusion Anisotropic diffusion

Answer 28

Like a ball (all directions) Like a rugby ball (specific direction of fibers)

Question 29

What is FA?

Answer 29

Fractional Anisotropy Map

Question 30

what is the role of Projection fibers

Answer 30

Connect cortex with other parts of the CNS

Question 31

Is the corticospinal tract purely motor?

Answer 31

No receives 30% of fibers from post central gyrus (sensory)

Question 32

Modern model of language pathway

Answer 32

Ventral :semantic: anterior middle TL speech comprehension Bilateral Dorsal: Phonological: sensorimotor Dominant

Question 33

Lateralisation of AF and Frontal Aslant tracts

Answer 33

Left-lateralised