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Accommodation
- Neural circuit to visual cortex and back
Conjugate gaze
- Hemisphere damage
- A hemisphere innervates the ipsilateral MR and the contralateral
LR
- Neither eye can move to contralateral side of damage
- The patient looks in the direction of the brain damage
- Medial longitudinal fasiculus damage (Multiple sclerosis most common
cause)
- Decreased ability of both eyes to look medial
- Convergence remains intact but on versions neither eye will adduct
- Internuclear ophthalmoplegia
Convergence
Dolls head movement
- Lag of eye position on sudden head movement
- Brain stem mediated
- Lack of dolls head would indicate damage to brainstem
Extraocular muscles
- Controlled by contralateral cortex
- ER6(SO4)3 enervation
- Parks 3 step test
- Hyper: Increase on gaze: Increase on head tilt
Muscle action:
- IR Depression Adduction Extorsion
- SR Elevation Adduction Intorsion
- MR Adduction
- SO Depression Abduction Intorsion
- LR Abduction
- IO Elevation Abduction Extorsion
Muscle fields (Direction of greatest strength)
SR(3) IO(3) SR(3)
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LR(6) <--| O.D. |--> LR(3) <--| O.S. |--> LR(6)
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IR(3) SO(4) IR(3)
- Rectus muscles act maximally when the eye is deviated temporally
- Obliques act maximally when nasal
- Corneal light reflex normally slightly nasal
- Forced duction test
- Forced generations test
- Hirschberg test
- <K = 0.5 mm nasal
- 1 mm deviation = 20 prism diopters
Nystagmus
Jerk
- Unidirectional
- Paretic muscle increases in direction of muscle direction
Pendular
- At birth
- Bilateral
- Rapid
- Familial or pathology
Miners
- After poor illumination for long time
Spasmus Nutans
Seesaw nystagmus
- MLF syndrome
- Brainstem lesion
Vestibular nystagmus
- Constant in all directions of gaze
- Bi-directional
- Endpoint
- Cerebellar lesion
Caloric stimulation
- Normal
- Cold water in ear
- Slow component towards direction of stimulation
- Fast component away
- No deviation of eyes
Lethargic
- Cortex less alert than brain stem so fast component becomes less
pronounced and eyes deviate towards damage
Stupor
- No fast component so eyes deviated to direction of damage
Coma
- Brain stem also depressed so no deviation or movement
Pupillary reflex's
- Direct neural circuit from midbrain
- Fixed and dilated causes
- Topical meds
- Jimson weed
- Scolopamine
- Intraocular iron foreign body
Vertical gaze
Visual field defect
- Fields in cortex are upside down and backwards to real field
- Nerve fibers temporal to fovea do not cross. Nasal fibers do cross.
- Damage to right hemisphere produces loss of left field O.U.
- Neither eye can see the contralateral side
Pre-chiasmal - Uni-ocular
- Defect in only one eye
- Nasal field defect will not go past horizontal
Anterior chiasm
- Central scotoma and contralateral hemianopsia
Chiasmal - Bitemporal hemianopsia
- Nasal fibers seeing lateral field decussate
- Hemispheres receives contralateral field
Post-chaismal - Homonopsia loss of opposite field
- Anterior cortex lesions may not effect central acuity
- Posterior cortex lesions reduce acuity
- Lesion of the lateral geniculate body (LGN)
- Wedge shaped hemianopsia pointing to fixation
- Often also have hearing and coordination problems (Proximaty)
Lesion of the temporal lobe
- Defect densest in superior quadrant ("Pie in the sky")
- Vertical border always respects midline
- Often also have speech problems
Lesion of the parietal lobe
- Defect inferior quadrantopsia ("Pie on the floor")
- Often also have nystagmus
Lesions of the occipital lobe
- Most often congruous hemianopsia's
- Often macular sparing
- In extreme cases "Cortical Blindness"
- Blindness denied in Anton's Syndrome
Field Indices
- False negative indicates inattention
- False positive indicates anticipation
- The more sensitive the point the lower the "apostilbs",
and the higher the "decibel" (db)
- Normal "Hill of vision" 29-37 db
- Drops 3 db for every 10 degrees from fixation
- Central drops 0.5 db every decade
- Peripheral drops 0.75-1.00 db every decade
Cranial nerves
CN I Olfactory
- Closed eyes, nostril occluded, identify smell
CN II Ophthalmic
- Damage would decrease visual acuity and direct reflex
- Swinging flashlight test
- Effected eye shows slight dilation on direct stimulation due to consensual
dilation when
- light is removed from other eye?
CN III Oculomotor nerve
- Adies pupil (Tonic pupil)
- Unilateral regular meiosis with slow reflexes and normal mydriatic
response
- Indicates Syphilis
- Bilateral irregular meiosis
- No direct or consensual reflex with poor mydriatic response
Opthalmoplegia
- Hypo-exotropia (Can’t look up, down or in)
- Mydriasis
- Blur at near
- Ptosis
Ptosis
-
Lesion of III nerve to levator muscle
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Lesion of sympathetic pathway of IV nerve
-
Acetylcholine transmission defect (Myasthenia Gravis)
-
Trauma
- Lid edema
Horners syndrome
- Miosis
- Ptosis
- Anhidrosis due to damage to sympathetic ganglia in neck
CN IV Trochlear nerve
- Superior oblique muscle (Can’t look down and out)
CN V Trigeminal sensory / motor nerve
- Distribution on face not back of head
- Trigeminal neuralgia idiopathic sever pain on one side of face
- Touch temporal cornea with cotton wisp; Blink?
- Close eyes and touch each side of face; Same?
- Clench teeth; Same muscle tone felt on jaw?
CN VI Abducens nerve
- Lateral recti muscles (Can’t abduct)
CN VII Facial sensory / motor nerve
- Facial asymmetry
- Wrinkle brow
- Close eyes tightly
- Smile
- Blow out cheeks
- Force closed eyes open; Same strength?
CN VIII Auditory nerve
- Eyes closed and ear covered
- Rub fingers together and determine how far away heard
- Weber test
- 256 HZ/512 HZ tuning fork
CN IX Glossopharyngeal nerve
- Pronounce vowels
- Open mouth and inspect for asymmetry See if ulva is pushed to side
- Touch cotton swab to side of throat and observe gag reflex
CN X Vagus nerve
CN XI Spinal accessory nerve
- Ask patient to elevate shoulders or turn head each way
- Compare neck muscle strength
CN XII Hypoglossal nerve
- Stick out tongue; Is it straight?
- Repeat tongue twister
- Push tongue against cheek
- Cerebral hemisphere damage
- (Example is if damage to left hemisphere:)
- Loss of smell left nostril
- Right homonymous hemianopsia
- No right conjugate gaze
- Hemianesthesia of right side of face
- Only slight chewing defect
- Lower right facial paralysis
Terminology
Agnosia
Apraxia
Aphasia
- Inability to understand or express words
Headache
- Unilateral more suggestive of mass lesion
- Throbbing suggests vascular
- Pulsatile suggests muscle contraction or traction
- Early AM suggests mass lesion
- PM suggests muscle contraction (Tension)
- Stiff neck suggests meningeal irritation
Pain sources
- Iritis
- Corneal abrasion
- Glaucoma
- Refractive error
- Muscle imbalance
- Inflamed or infected sinuses
- Temporal mandibular joint dysfunction (TMJ)
- Cervical spine arthritis
- Neck muscle contraction
Generalized
- Elevated intra-cranial pressure
- Hypertension
- Meningitis
- Migraine?
- Psychogenic
Focal
Bilateral
Frontal
- Frontal sinusitis
- Maxillary sinusitis
- Referred
Occipital
- Cervical lesion
- Fossa lesion
- Referred
Midline
Unilateral
Shifting (Right, left, right)
Always same side
- Arterio-venous malformation
- Cluster
- Glaucoma
- Migraine?
- Neoplasm
- Temporal arteritis
- Trigeminal neuralgia
Cluster headache
- Type of migrain
- Men at night
Herpes zoster prodome
- Periorbital
- May develop zoster vesicles in 2-5 days
Mass lesion
- Reproducible in same location
- Worse in AM - may wake up in night
- No tumor if central retinal venous pulsation (CRVP)
- Often memory or personality changes
Migraine headache
Classic
Common
Ophthalmic migrain
- Pain in eye
- Nausea, vomiting
- Ophthalmoplegia.
- Ptosis usually clears in 1 mo.
- Usually kids
Multiple dystrophy
Multiple sclerosis (MS)
- Ptosis
- Optic neuritis
- Uthoff’s sign
- Decreased acuity in a warm bath
Myasthenia gravis (MG)
- 20 yr. old 3:1
- Female
- Middle age
- Mainly male
- 95% have ocular problem
- Variable muscle weakness
Parkinson's disease
- Ratcheting movement
- Shuffling gait
- Tremor
Temporal arteritis
- Giant cell arteritis
- 80% Age 70+
- Rare in blacks
- Headache, jaw and scalp pain
- Stiff neck, shoulders, back, legs
- loss of visual acuity
- Throbbing pain at temple
- Pain on chewing
- Diagnose by SED rate
Pituitary tumor
- Superior temporal field defects
Acidophillic
Basophillic
- Full face
- Diabetes
- Sodium metabolic upset
- Adiposity
Chromophobe
- Laurence-Moon-Biedel syndrome
- Decreased libido
- Irregular menses
- Hair and skin changes
- Adiposity
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