CM-BS & CN in Relation to Multiple Sclerosis

Question 1

Brain Stem

Answer 1

Includes medulla, pons, and mesencephalon (midbrain)
Extends from pyramidal decussation the posterior comissure
Cranial nerves 3 to 12
blood supply vertebrobasilar system
Reticular formation as its central core integrating center of CNS as it receives collaterals from most AFFERENT

Question 2

Brainstem reflexes

Answer 2

Pupillary light reactions (2+3)
Doll’s eye movement (3,4,6+8)
Corneal reflex (5+7)

Question 3

Functionally distinct ascending and descending tracts are spread along the

Answer 3

transverse axis

Question 4

Functionally distinct cranial nerve nuclei are spread along the

Answer 4

rostrocaudal axis

Question 5

Long tract signs occur

Answer 5

Contralateral to the lesion

Question 6

Cranial nerve signs occur

Answer 6

Ipsilateral to the lesion

Question 7

OculOmOtOr and trOchlear nuclei

Answer 7

Diplopia (dbl vision)
Ipsilateral pupillary disturbance with ptosis (oculomotor
n. )
level of MIDBRAIN

Question 8

Abducens nucleas and facial nucleus

Answer 8

Diplopia (abducens)
Ipsilateral facial weakness (facial n.)
level of PONS

Question 9

Nucleus ambiguus (CN9/10/12)

Answer 9

DORSAL nucleus of VAGUS and HYPOGLOSSAL nucleus
Disturbnce of : speech/swallowing
level of MEDULLA

Question 10

Corticospinal tract

Answer 10

Hemiplegia on the opposite side of the lesion

MEDIAL TO BRAINSTEM

Question 11

Medial leminiscus

Answer 11

Loss of vibration and position sensation on the opposite side of the lesion
MEDIAL TO THE BRAINSTEM

Question 12

Spinothalamic tract

Answer 12

Contralateral loss of PAIN AND TEMP sensation

LATERAL to brainstem

Question 13

Descending sympathetic fibers

Answer 13

Horners syndrome : ptosis and miosis

Lateral locatiom

Question 14

MS

Answer 14

T cells cause demyelination and destruction of axons in WHITE MATTER/CEREBRAL CORTEX ( I guess grey matter also )

Question 15

CAUSES OF MS

Answer 15

identical twins 25%
WHITE 
WOMEN x2 than men
Low immunity
Risk increases w distance from equator
Geographic risk is equal after age 15
Western : HLADR15/DQ6
Kuwait : DR4
Epstein barr virus INFECTION
Metabolic : low sunglight (UV-B)
Low vit D (interacts w HLA DR15)
Toxins : smoking

Question 16

Diagnosis of MS

Answer 16

Clinical
MR
Lumbar puncture ( examins oligoclonal bands in CSF)
Visual evoked potentials

Question 17

Prevalence of MS

Answer 17

prevalence : 100/150 per 100,000
Incidence : 7/100,1000
Wordwide 2.5 mill have MS

Question 18

Primary vs 2ndry progressive MS

Answer 18

Primary : from the beginning, symptoms gradually develop and worsen over time (10-15%)
2ndry :follows on from relapsing/remitting worsening symptoms (50%)

Question 19

Clinical features of MS

Answer 19

Brainstem/Cerebellar (20%)
Oculomotor : diplopia
Speech probs ( dysarthria ) / swallowing ( dysphagia )
Vertigo, nausea, vomitting, unsteadiness (ataxia)
Facial numbness & weakness
Paroxysmal symptoms : trigeminal neuralgia, tonic spasm
LEGS ARE AFFECTED MORE THAN ARMS > ASYMMETRIC
Lhermitte’s sign: Unpleasant sensation in the back, and radiating
into leg on flexing the neck

Question 20

Inter nuclear ophthalmoplegia (INO)

Answer 20

Lesion of  the medial
longitudinal fasciculus
(MLF) and causes
diplopia • In left INO:
– Impairment of
adduction of  the left
eye – Nystagmus of  the
right abducting  eye
 Causes:
– Multiple sclerosis
– Stroke
– Vasculi tis

Question 21

Oculomotor nerve palsy

Answer 21

1. Aneurysm of the post communicating artery : compress the superficial parasympathetic pupiloconstrictor fibers-dilated pupil
2. Uncal herniation : increased intracrianial P. 2ndry to space occupying lesion (tumor, absces, hemorrhage)
3. Cavernous sinus thrombosis
4. Midbrain infarction