Brainstem Introduction Flashcards
Three exceptions for cranial nerve location is lesion location?
- Loss of pain and temp sensation in face w/ preserved touch (caudal to trig nerve)
- Weakness of face that preserves strength in upper face = damage from motor cortex above level of cranial nerve on opp side
- Inability to move either eye to one side is due to damage to medial pons on that side
How to differentiate medial vs lateral brain stem lesions?
Lateral Lesions: usually produce sensory cranial nerve damage
Medial Lesions: produce motor cranial nerve damage
General locations of brain stem
Lateral (dorsal) = alar plate = sensory
Medial (ventral) = Basal plate = motor
Split by sulcus limitans
Autonomic nerves on either side of sulcus
2 causes of stroke?
Ischemic and Hemorrhagic
3 main types of ischemic stroke?
Small vessel disease
Large vessel disease
Emboli
Small vessel disease
Usually due to age, hypertension, smoking, diabetes
Tiny blood vessels thicken with smaller lumen
Easily occluded
Large Vessel Disease
Hardening of the arteries “plaque”
Stroke often due to sudden clot on plaque
Same risk factors, old age, hypertension, diabetes, high cholesterol
Embolic Stroke
usually small blood clots
Often come from heart
Risk factors: a fib, bad heart valves, recent MI, CHF, `
Arterial Dissection
Often painful
Can be carotid or vertebral artery
Spontaneous or traumatic
How do I know if there’s a brain stem lesion?
Cranial nerves involved (level of nerve is usually level of lesion)
Often sensory or motor loss on contra lateral side of body
How to know if there’s a brainstem lesion?
Cranial nerve involved
Sensory or motor loss contralateral body
Lateral Lesion
Loss of pain and temp on contralateral body
HORNER’S SYNDROME: loss of ipsilateral head sympathetic
If affect middle or inf cerebellar peduncle -> incoordination
Medial Lesion
Contralateral weakness
If midbrain lesion, could affect superior cerebellar
