neuro: brain stem/cranial nerves Flashcards
mnemonic for motor/sensory innervation of cranial nerves
Some say marry money but my big brother says brains matter more
what cranial nerves come from midbrain
CN III (oculomotor)- medial
CN IV (trochlear) - from below inferior colliculi (from posterior aspect)
what 2 arteries above and below oculomotor (cigarette)
above - posterior cerebral
below - superior cerebellar
If a patient had an isolated trochlear nerve palsy, what sensory deficit would you expect
no sensory innervation by trochlear so nothing
features of a complete 3rd nerve palsy
Eyes down and out (hypotropria + extropia)
Ptosis - drooping eyes
Dilated pupils
3 nerves at pontomedullary junction
facial(medial)
abducens
vestibulocochlear(lateral)
Compare the clinical signs in an upper vs. lower motor neuron facial nerve lesion
upper
-forehead is spared due to compensation so both eyebrows are fine but one side of mouth paralysed
lower
-Bell’s palsy- one sided weakness of facial muscles
Which clinically important tract descends in the pyramids of the medulla
Corticospinal
Why might damage to the inferior cerebellar peduncle cause gait ataxia
Inferior is responsible for coordination + motor
nerves in dorsolateral(behind olive)/venterolateral (infront) sulcus
dorsolateral
- Glossopharyngeal
- vagus
- Accessory
ventrolateral
-hypoglossal
A stroke affecting which brain stem nucleus might affect speech and swallowing
nucleus ambiguous
clinical features of unilateral hypoglossal nerve palsy
When sticking out tongue, moves towards side affected (lick the lesion)
identify which nerves enter the skull (foramen)
Cribriform plate of ethmoid
-olfactory filaments
Optic canal (sphenoid bone) -optic nerve
Superior orbital fissure
- Oculomotor
- Opthalmic branch
- Abducens
- Trochlear
Foramen rotundum
- V2 maxillary
Foramen ovale
-V3 mandibular
Foramen spinosum
-Middle meningeal artery
Internal auditory meatus
- Facial
- Vestibulocochlear
Jugular foramen
- Glossopharyngeal
- Vagus
- Accessory
Hypoglossal canal
- Hypoglossal
