Spinal Cord Tracts

Question 1

Sulci and fissures

Answer 1

Longitudinal fissure
Lateral Sulci
Central Sulci (easier to see on lateral view)
Parieto-occiptal sulci

Question 2

Frontal lobe regions

Answer 2

Primary motor cortex (Motor UMN corticospinal tracts)
Frontal eye fields (Eye movement)
Broca’s area (motor speech)

Question 3

Parietal lobe regions

Answer 3

Primary Sensory cortex (post central gyrus): contralateral sensory input

Angular Gyrus
Dominant lesion: math, writing, Left from right, IDying fingers (Gerstmann Syndrome)
Nondominant lesion: Hemispatial neglect

Question 4

Temporal Lobe regions

Answer 4

Superior Temporal gyrus: Primary auditory cortex, Wernicke’s area

Hippocampus
Amygdala
Fusiform Gyrus: Facial recognition, lesion=Prosopgnosia
Uncus: assoc with seizures, herniation= CNIII compression

Question 5

Occipital Lobe regions

Answer 5

Primary visual cortex

Question 6

Posterior limb of the internal capsule (ant 2/3rds)

Answer 6

motor fibers of the corticospinal tract

Question 7

Posterior limb of the internal capsule (posterior 1/3)

Answer 7

Sensory fibers of the thalamocortical tract

Question 8

Genu of the internal capsule

Answer 8

Motor fiberes of the corticobulbar tract

Question 9

Spinal nerves exit below their respective vertebrae at what levels?

Answer 9

T1 through S5

Question 10

Lumbar puncture passes through what layers

Answer 10

1- Skin
2- Facia and SC fat
3- Surpaspinous ligament
4- Interspinous ligament
5- Ligamentum flavum
6- Epidural space and fat (epidural anesthesia needle stops here)
7- Dura

Question 11

Spinal tracts:

Dorsal Column responsible for

Answer 11

proprioception and vibration sensation

Question 12

Spinal tracts:

Spinothalamic tracts responsible for

Answer 12

pain and temperature

Question 13

Corticospinal tract responsible for

Answer 13

descending motor innveration

Question 14

Dorsal column course

Answer 14

1st neuron through Dorsal root ganglion

Up through Dorsal column (fasciculus gracilis for lower extremity, fasciculus cuneatus upper extremity)

synapse in medulla on nucleus gracilis/fasciculus

2nd neuron decussates on contralateral medial lemniscus and travels up–> synapses on venteroposterolateral nucleus in thalamus

3rd neuron to ipsilateral somatosensory cortex

Question 15

Spinal thalamic tract (anterolateral tract) course

Answer 15

1st neuron enters DRG

Synapses in ipsilateral gray matter posterior horn

2nd neuron decussates through anterior white commisure

ascends through contralateral white matter

synapses on VPL in thalamus

3rd neuron travels ipsilateral somatosensory cortex

Question 16

Descending corticospinal tract course

Answer 16

1st neuron leaves primary motor cortex and travels through internal capsule and reaches medulla

Decussates at medullary pyramids

Descends through contralateral posterolateral white matter

synapses in anterior horn of gray matter

2nd neuron exits spinal cord through anterior root

synpases at NMJ

Question 17

Upper motor neuron damage to the cortico spinal tract can occur at any point between primary motor cortex and the anterior horn gray matter. These signs include

Answer 17

Babinski reflex
spastic paralysis
clasp-knife spasticity
Increased tone and reflexes

Question 18

Lower motor neuron of the corticospinal tract can occur ta any point from the anterior horn gray matter in the spinal cord to the NMJ. Sign of LMN damage include

Answer 18

Atrophy
Fasciculations
Decreased tone
Decreased Reflexes

Question 19

What is the Romberg test?

Answer 19

Patient closes eyes to see if ataxia is cerebellar or dorsal column related

Need proprioception (DCML), visual aids (Cerebellum)to keep balance. Positive romberg means DCML issue

Question 20

Bilateral symmetric loss of pain and temperature sensation in cape-like distribution seen with Chiari 1 malformation causes issues to the Spinothalamic tract just at the that level because

Answer 20

That’s where the 2nd order neurons are crossing over but doesn’t affect the other levels, can affect other tracts though. syringomyelia