where in the cns

Question 1

brain components

Answer 1

cerebral hemisphere - contralateral signs: hemiparesis (visual/cognitive defects)
brainstem - contralateral signs (affecting CN, ataxia, diplopia)

cerebellum - does not give UMN signs - IPSILATERAL ataxia (cause UMN does not go through cerebellum). cerebellum is behind brainstem - if brainstem is affected, will also have cerebellar effects

Question 2

cerebral hemisphere

Answer 2

• grey matter - awareness, language, communication, power
• white matter - myelinated. pure motor symptoms
• basal ganglia - controls movement

subcortical lesions: sensory/motor syndrome
cortical lesions: sensory/motor + cortical (unilateral neglect) syndrome

Question 3

brainstem

Answer 3

• midbrain: CN 1&2
• pons: CN 5,6,7,8
• medulla: CN 9,10,12

motor and sensory tracts

• spinocerebellar
• cerebellocortical

reticular formation: breathing and consciousness
stroke at the brainstem -> loss of involuntary breathing + consciousness

also cause horner syndrome

Question 4

brain vs cord lesions

Answer 4

brain: unilateral
cord: bilateral + affects sphincters also

Question 5

cerebellum lesion effects

Answer 5

eyes: nystagmus, dysmetric saccades
mouth: dysarthria
arms: rebound, dysmetria (finger to nose test), dysdiadochokinesis (test: the roti prata thing on palm)
legs: broad based gait (counter instability), heel shin ataxia

Question 6

spinothalamic

Answer 6

pain and temperature

decussate at spinal cord

Question 7

dorsal column medial leminscus

Answer 7

proprioception and vibration

decussate at brainstem

Question 8

eg. right sided loss of pain & temp
left sided loss of vibration & proprioception
bilateral UMN weakness in legs
where is the lesion?

Answer 8

bilateral = lesion at the spinal cord
DCML - havent decussate yet - follows DCML
ans: left sided lesion at spinal cord

Question 9

horner syndrome

Answer 9

failure of the sympathetic system

• ptosis
• miosis (pupil contraction)
• anhidrosis (sweat): lack of sweat - cause dilation of vessels, appears red