CRANIAL NERVES
CN I - Olfactory
CN II – Optic Ophthalmoscope Dark room (to maintain large pupil)! Start negative (ppl w myopia) and move to positive Med intense, med size Start 15 deg lat, once see optic disk, ask pt to look into light – this will change view to their macula/fovea Your left/their left Pt look up and straight
Normal
Smell Different aromas (Pts eyes closed) Patency Septum Check both nostrils Visual acuity (hand held card @ 14”) Visual Fields by confrontation (peripheral vision) Red reflex Retina
Optic disc (should be creamy yellow/orange and round or oval) Margins distinct Blood vessels
Macula, fovea centralis
Cover one nostril, breathe in with other
ABNORMALITY Absence of smell aging, smoking, nasal disease Absence of sniff = obstruction
Mucosa slightly redder than oral mucosa
Perforation – trauma, cocaine use; Deviation, Epistaxis
20/20 20/40 – person sees at 20 feet what’s normally seen at 40 N = 50° upward, 90° temporal, 70° down, 60° nasal N= blind spot at 15 deg Retina should appear to be red. “Orange glow” Red / orange
Myopia: nearsighted; Hyperopia: farsighted; Presbiopia: aging
Follow blood vessels to optic disc
Veins - bigger, darker ones Arteries -smaller, brighter red structures Macula - lateral to the optic disc, looks somewhat darker then the rest of the retina fovea centralis – center of macula
Pituitary tumor - Peripheral field lost Glaucoma, optic neuritis, papilledema - enlarged blind spot Opaque black areas with cataracts or detached retina Hypertension - flame shaped hemorrhages Diabetes – deep retinal hemorrhage (red blots) Papilledema—blurred margins & elevation of disc (inflammation) Glaucoma – looks very white & atrophy may be seen Hypertension - Copperwire and narrow arteries Clumped pigment with retinal detachment
Glaucoma—optic nerve atrophy Neovascularization—cancer
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Eyelids for drooping Pupil size for equality Direct & Consensual response to light
Symmetry – both sides Pupil reactions should be equal. A) Direct light reflex Pupil constricts to direct light
Accommodation – follow finger to bridge of nose
Converge (cross eyed)
H test: CN III • upward/out movt: superior rectus • upward/in: inferior oblique • inward: medial rectus • downward/out: inferior rectus
CN VI (6)- Abducens
H test: Downward/inward eye movement H test: Lateral eye movement
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Inspect for muscle atrophy, tremors Palpate jaw mms: temporal & masseter for tone & strength on clenching teeth
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Facial sensation in each branch: o Forehead: ophthalmic o Cheeks: maxillary o Chin: mandibular
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Corneal reflex: Whisp test: tearing & blinking
CN V – Trigeminal
CN VII – Facial
Aniscoria – unequal pupil constriction
B)Consensual light reflex Pupil constricts to light shining on opposite pupil
CN III – Oculomotor
CN IV - Trochlear
Ptosis— droopy eyelids (CN III damage) seen in Myastenia gravis and Horner’s syndrome Glaucoma – fixed dilation
Inspect symmetry of facial features: • Smiling • Frowning • Closes eyes tightly
Failure of convergence with CN damage
H Test: - Extraocular muscle movements Nystigmus - eye tremor seen is MS, brain lesion, CN palsy - Lateral & vertical mov’t disorder (look at magnitude & direction)
Superior Oblique (SO4) Lateral Rectus (LR6) ABN = weak or absent contraction suggests lesion of CN 5 Equal muscle bulk, tone & strength
Equal sensation on both sides
Afferent: CN V Efferent: CN VII
Blinking and tearing
Trigeminal nerve palsy - unable to feel touch of cotton wool (no blinking) Facial nerve palsy - patient can feel the touch of the cotton wool no reflex blink & tear (CN7) Bell’s Palsy – Asymmetry of face.
Symmetry of patient’s face.
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w/ Drs attempt to open Shows teeth Puffs cheeks w/ resistance Wrinkles forehead Lifts eyebrows
Whisper test: Hearing Weber: Lateralization
N = patient can repeat back whispered word N = sound is heard midline, or equally in both ears.
CN VIII – Acoustic Rinne: Air & Bone
Normal AC>BC
conduction Otoscopic:
Tympanic membrane
CN IX – Glossopharyngeal
CN X – Vagus
Oral inspection: (tongue depressor)
CN XI – Spinal Accessory
TM is pinkish grey, oblique membrane held inward at its centre by the handle of the malleus. should point toward jaw
Cone of light Swallowing Gag reflex (don’t need to do) Taste post 1/3 tongue sour & bitter (just explain) Inspect palate for symmetry Patients says “ahhhh” – note rise of soft palate (say AH) (symmetry and uvula Uvula rise
ABN = unable to repeat word CHL: sound lateralizes to impaired ear (causes are acute OM, perforation, obstruction, otosclerosis) SHL: sound lateralizes to good ear (long-term exposure to loud noises, drugs, infections of the inner ear, trauma, tumours…) CHL: AC=BC or BC>AC SHL: AC>BC Otitis media: inflamed/red TM Perforation of TM
CN 10 paralysis – soft palate fails to rise and uvula deviates to opposite side (good side)
centered) & gag reflex elicited
Swallowing Speech sounds
ABN = dysphagia
Sternocleidomastoid mms strength • Pt turns head to each side against resistance Trapezius mms strength • Pt shrugs shoulders against resistance
ABN = pain or difficulty performing actions paralysis of muscle
Talking: note Hoarseness, Nasal sounds
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CN XII Hypoglossal
Inspection • Tongue in mouth & while protruding • Tongue mvt toward nose & chin Test Strength • Test index finger when tongue is pressed against cheek Evaluate Quality of lingual speech
- Tremor - Atrophy - Deviation towards affected side
- Presence of lisp
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