Stroke Alfred Sat

Question 1

What fibers cross over at lower medulla?

Answer 1

Motor fibres

Posterior fibres (vibration, proproception, light touch)

Question 2

What fibers do the external capsule carry?

Answer 2

Cholinergic fibers from basal forebrain to the cerebral cortex

Question 3

What fibers are carried in the internal capsule:

1. Anterior limb
2. Genu
3. Posterior limb

Answer 3

1. Anterior limb
   
   1. Thoracocortical to frontal lobe
   2. Frontopontine (SHAM functions - emotional smile, horizontal gaze, accomodation, micturition)
2. Genu
   
   1. Corticobulbar
3. Posterior limb
   
   1. Thoracocortical fibers to the parietal lobe (general sensation)
   2. Corticospinal fibers + corticorubral fibers

Question 4

What is the definition of lower motor neuron?

Answer 4

Anterior horn cell + after

Question 5

Where are the 5th and 7th CN located in the pons?

Answer 5

5th nerve exits from the middle of the pons

7th nerve exits from the lower pons

So a lesion in the higher pons causes a contralateral facial (CN VII) UMN paralysis and a lower pontine lesion causes an ipsilateral LMN 7th

Question 6

What are the clinical manifestations of a medial pontine lesion?

Answer 6

Motor dysfunction and INO and gaze palsy

Question 7

What are the clinical manifestations of a lateral pontine lesion

Answer 7

• Pain and temperature (below high pons pain and temp are lost ipsilaterally in the face and contralaterally in the limbs)
• Vertica nystagmus
• 8th nerve dysfunction
• Ipsilateral ataxia
• Ipsilateral horner’s in high pontine lesion

Question 8

What are the manifestations of lateral medullary syndrome

Answer 8

Ipsilateral:

• facial numbness
• limb ataxia
• Horner’s syndrome

Contralateral:

• loss of pinprick and temperature in arm and leg

Question 9

What causes:

1) lower quadrant hemianopia
2) upper quadrant hemianopia

Answer 9

1) Parietal
2) Temporal

Question 10

What other fibers do the optic nerve carry? (aside from vision)

Answer 10

Afferent fibers for light reflex

Question 11

What are the findings in a cranial nerve IV palsy?

Answer 11

Superior oblique affected - weakness of downward eye movement with vertical diplopia that is worse when the eye is adducted and improved on contralateral gaze

Weakness of intorsion, in particular with the eye abducted

Question 12

What are the 2 gaze centers and 2 connections involved in an INO?

Answer 12

Gaze centres:

• Frontal gaze centre and contralateral pontine gaze centre

Tracts:

• Medial longitudinal fasicle connects 3rd CN nuceus to pontine gaze centre
• Paramedian pontine reticular formation connects 6th nerve nucleus to pontine gaze centre

Question 13

What is the clinical manifestation of damage to the frontal gaze centre?

Answer 13

Cannot look towards paralysed size (deviates away from hemiparetic limb)

Question 14

What are the 3 causes of complex opthalmoplegia?

Answer 14

Myasthenia

Graves eye disease

Mitochondrial myopathies

Question 15

What nerves comprise the gag reflex?

Answer 15

Sensory - CN IX (glossopharyngeal)

Motor - CN X (vagus)

Question 16

What is the CN that is most likely to be affected in the cerebellopontine angle?

Answer 16

CN 8 but also 5-7

Question 17

What nerves are involved in cavernous sinus lesions?

Answer 17

CN 3-6

Question 18

What speech patterns are present in pseudobular palsy vs bulbar palsy?

Answer 18

Pseudobulbar palsy is nasal

Bulbar is spastic

Question 19

Where do pain and temperature fibers cross over?

Answer 19

At the level of entry

Question 20

Where do proprioception and vibration cross over ?

Answer 20

At the lower level of the medulla

Question 21

Where do light touch fibers cross over?

Answer 21

Both at the level of entr into the spinal cord and in the lower medulla

Question 22

How are the fibers of the corticospinal tract laid out in the spinal cord (e.g. is arm medial or latera)

Answer 22

Medial - > Lateral

Arm -> trunk -> leg

Question 23

Loss of motor functions, pain/temperature with sparing of proprioception and vibratory sense with initial tone flaccid and loss and deep tendon reflexes

Answer 23

Anterior spinal artery syndrome

Question 24

LMN weakness with no sensory finding

Diagnosis?

Answer 24

Anterior horn cells affected - likely polio

Question 25

Loss of proprioception and UMN weakness - diagnosis?

Answer 25

Subacute combined degeneration

Question 26

What area is purely supplied by the radial nerve without any overlap?

Answer 26

Anatomical snuffbox

Question 27

Where is the damage to the radial nerve is there is no sensory deficits and only partial wrist drop, finer drop and weakness in extension of the hand and fingers?

Answer 27

Radial head/entrapment in the arcade of frohse (posterior interosseous)

Question 28

Which finger flexion points does the median nerve supply?

Answer 28

All PIP joint

Index and middle finger flexion at DIP

Lumbricals to digits 2 and 3 (flexion at MCP)

Thumb movements

Question 29

What is pyramidal weakness?

Answer 29

UMN weakness pattern - antigravity muscles are weaker than pro gravity