CN Neuro Flashcards
Which CNs come from midbrain?
CN3: oculomtor
CN4: trochlear
Which CNs come from pons?
CN5: trigeminal
CN6: abducens
CN7: facial
CN8: vestibulotrochlear
Which CNs come from medulla?
CN9: glossopharyngeal
CN10: vagus
CN11: hypoglossal
CN12: accessory
Function and name: CN1
Olfactory - smell
Function and name: CN2
Optic
Vision
Function and name: CN3
Oculomotor
- pupil contstriction
- accomodation
- upper eyelid
- palsy: down and out, can’t adduct eye
Function and name: CN4
Trochlear
Eye movements
Palsy - up and in
Superior oblique muscle - responsible for depression and intorsion of eye
Function and name: CN5
Trigeminal
Sensory of face
Motor - muscles of mastication
Function and name: CN6
Abducens
Eye movements
Palsy - in and stuck - cannot abduct eye, eye turns medially when looking forward
Function and name: CN7
Facial
Facial muscles of expression
Taste anterior tongue
Plasy: INCLUDES forehead
Function and name: CN8
Vestibulotrochlear
Hearing and balance
Function and name: CN9
Glossopharyngeal
Sensation posterior tongue + pharynx, taste posterior tongue
Function and name: CN10
Vagus
ANS
Larynx, pharynx, vocal cords
Palsy: uvula deviates away (because soft palate in deviated side dose not rise)
Function and name: CN11
Hypoglossal
Movement of tongue
Palsy: tongue deviates toward affected side
Function and name: CN12
Accessory
Motor trap and SCM
Rinnes test - explain
Tuning fork - hit, put on bone, say when can’t hear, put to ear
Normal or SNHL: air > bone
Conductive loss: bone > air
Webber test - explain
Interpret
Shake tuning fork, put on middle of head
Normal: middle
Abnormal:
- conductive: heard in bad ear (with abnormal bone > air Rinne)
- SNHL: hear good ear (with normal Rinnes)
Causes of conductive hearing loss
EXTERNAL EAR (before TM)
- debris, wax, FB
- congenital malformations: Aural atresia, microtia
MIDDLE EAR
- OM/ effusions
- Cholesteatomas (congenital or acquired keratinised squamous epithelium that forms a cyst)
- Otosclerosis (spongy bone replaced by sclerotic bone)
HEAD TRAUMA - previous temporal bone # can cause mixed HL
What’s this? What’s type 4?
Microtia
Anotia
What this?
Typanoscleorsis - grommets or recurrent OM
Syndromes w conductive hearing loss
Treacher-collins: coloboma, micronatia, small mid face, normal IQ
Sticker syndrome: cleft plate and micrognatia (25% PRS), marfanoid habitus, hyperextensible joints, XR: dumbbell shaped long bones
22q11
BWS
Causes of SNHL
Congenital:
- Syndromic (Waardenburg, Usher, Pendred, Alport, Jervel Lange-Nielsen)
- non-syndromic: most common connexin 26 mutation
Infection: CMV, toxoplasmosis, herpes, rubella
Ototoxic drugs: aminoglycosides (gent), frusemide, cisplatin
Autoimmune: SLE, RA
Unilateral:
Trauma - temporal bone #
Tumour - acoustic neuroma in NF2
Syndromic causes SNHL
Jervell and Lange-Neissen sydrome: prolonged QTc - syncope, sudden death
Waardenburg: white forelock, bright blue eyes
Usher: hearing loss and visual impairment
Pendred: thyroid - goiter/ hypothyroid
Alport: XL, kidney, eye
Invx for hearing loss
Audiology
CT - bones
MRI - mass, soft tissue
ENT rv
Speech developmental assessment -? Referral for neuropsych
Serology - CMV, toxo, rubella
Autoimmune? ANCA, ANA, dsDNA, ESR
Pendred - thryoid
Jervell and Lange-Neissen - ECG for prolonged QTc
Which CN?
What branches each colour?
Where’s the SWS port wine stain?
CN 5: trigeminal
Green - V1: ophthalmic
Blue - V2: maxillary
Red - B3: mandibular
V1+V2 branches SWS
What’s this?
Possible causes
UMN plasy - because forehead is spared!
Central lesion - malignancy, vascular, autoimmune
What’s this?
Possible causes?
CN7 Facial nerve palsy
Forehead involved!
Idiopathic Bells palsy- ? Viral prodrome
Infection: Ramsay-Hunt Syndrome (VZV)
Neoplastic:
- meningioma (NF2)
- acoustic neuroma (NF2)
Stroke
Autoimmune: MS, GBS
Asked to do motor cranial nerve exam
Eyes
Trigeminal (wasting jaw, jaw jerk)
Facial
Mouth (9, 10, 12)
Accessory - SCM, trap
(No olfactory, no sensation, no hearing tests)
