The UIC Eye Manual
Produced by the faculty and residents at the Department of Ophthalmology
and Visual Sciences at the University of Illinois at Chicago
DISCLAIMER--PLEASE READ
While every attempt has been made to have dosages, medications, and
treatment recommendations as accurate and up to date as possible, this manual
is no substitute for clinical judgement and knowledge. UIC and the authors are
not liable for any action taken on the basis of this manual.
NEURO-OPHTHALMOLOGY
Revised by Bienvenido V. Castillo, Jr., MD
Editor Balaji Gupta MD
I. Neuro-ophthalmologic examination
A. History
Determine type of visual disturbance
decreased visual acuity, complete loss of vision, scotoma, or other localized visual field
loss, metamorphopsia, monocular or binocular diplopia , oscillopsia, etc.
Unilateral or bilateral (within the visual field), one eye or both
-important in formulating differential diagnosis and approaching evaluation
- eg. loss of vision one eye (monocular) generally indicates pathology limited to the optic
nerve (ischemic, inflammatory or compressive) whereas binocular involvement may
indicate homonymous hemianopia from pathology affecting the visual pathways from the
optic chiasm to the visual cortex.
Onset and duration
acute - typical for an ischemic or hemorrhagic vascular cause
subacute - typical for an inflammatory processor toxic/nutritional disorders
slowly progressing - seen in compressive (tumors) or toxic/nutritional disorders
Associated systemic disturbances
headache, weakness, fever, weight change
Family history
B. Examination and testing
Visual acuity
Color vision
Ishihara plates
Subjective estimate of red desaturation
Pupillary resonse
check for anisocoria, afferent pupillary defect, light -near dissociation, and sluggishness
Photostress recovery test
-helps in differentiating visual loss due to optic nerve disease or maculopathy.
-bright light is shone for 10 sec at a distance of 2-3 cm.
-record time it takes for patient to be able to recover and read at his/her best acuity (or
next larger line) on Snellen chart.
-recovery time prolonged in maculopathy (90-180 sec) but normal in optic nerve disease
(less than 60 sec).
-valid only for patients with visual acuity of 20/80 or better.
Spatial contrast sensitivity
-measures contrast threshold using gratings of various sizes and background
-elevated contrast threshold may be seen despite visual acuity of 20/20 in diseases such as
cataracts, glaucoma, macular lesions, optic neuropathies, and cerebral diseases.
Visual field testing
Confrontation testing
-crude but easy method of quickly assessing visual field
-should usually be followed by more sensitive tests such as Goldman perimetry or tangent
screen testing if patient is capable (confrontation may be the only test some patients can
respond to reliably).
Amsler grid
-useful for testing central 20°.
-look for discontinuity or distortion of lines
Tangent screen
-evaluates the central 30° field
-may be useful in identifying small scotoma not detected by bowl perimetry
Bowl Perimetry
Goldmann perimeter
-useful for evaluating both central and peripheral fields.
-utilizes static and kinetic testing
-manual and operator dependent
Automated bowl perimeters
-evaluates only the central field (30° or 60°)
-utilizes static testing
-standardized with statistical evaluation of data
-may be difficult for some patients
Visually evoked cortical potentials (VECP)
-records electrical signals in the cortex generated by stimulation of the retina with light.
-a measure of macular visual function because of the disproportionately large
representation of the fovea in the occipital cortex.
-p100 wave - positive deflection that occurs at 100 msec after the stimulus is most
reliable parameter to measure.
latency increased in disorders with demyelination as a component of pathology including
multiple sclerosis, optic nerve compression, infiltration or toxicity.
amplitutde may be decreased in all conditions that reduce visual acuity.
Gaze and Ocular motility
Nine cardinal positions
Rotational testing
-involves vestibulo-ocular reflex
-useful for infants and comatose patients
Parks-Bielschowsky 3 step test
test for hypertropia
Step 1: Determine eye with hypertropia at primary gaze
4 possible paretic muscles each eye (SR,SO,IR,IO)
Step 2: Hypertropia increases at lateral gaze
ipsilateral (gaze toward hypertropic eye)
inferior muscles (affected eye in abduction where rectus muscles are primary vertical
deviators)
contralateral (gaze toward hypotropic eye or away from hypertropic eye)
superior muscles (affected eye in adduction where oblique muscles are primary vertical
deviators)
Step 3: Hypertropia increases on head tilt
ispsilateral to hypertropic eye - oblique muscle
contralateral to hypertropic eye - rectus muscle
Maddox rod testing
-for evaluation of tropias and cyclodeviations
-right eye covered with Maddox rod and cylinder aligned in same direction of deviation.
(This avoids confusion over the pattern that results from reversing which eye has the rod).
-uncovered eye fixates on light
-red line appears separate from white light when latent (phoria) or manifest (tropia) ocular
deviation exists. (Maddox rod brings out latent deviations by eliminating fusion).
-axis and size of deviation determined by rotation of Maddox rod and correction with
prism
Alternate prism cover testing
-cover-uncover test used initially to distinguish tropia from phoria
-eyes are covered alternately as patient fixates on a target
-test positive if each uncovered eye move to re-fixate on target
-axis and degree of deviation determined by position and power of prism necessary to halt
eye movement.
II. Neuro-imaging
A. Indications
Unexplained loss of vision
Optic disc edema
Suspicion of intracranial tumor
Evaluation of proptosis
Cranial nerve palsy
Acquired nystagmus
Supranuclear eye movement disorders
Evaluation of demyelinating diseases
B. Computed tomography (CT scan)
-utilizes x-rays
-readily available and relatively inexpensive
-provides good images of the brain and orbit except in the posterior fossa
-provides excellent detail of bony architecture and sites of bleeding
(hemorrhage/hematoma)
C. Magnetic Resonance Imaging (MRI)
--excellent anatomic detail of the brain, orbit, and other soft tissues
-shows demyelinating changes not visible in CT
-poor in evaluating bony architecture or acute bleeding
-requires longer time and may elicit claustrophobia
-contraindicated in patients with metallic foreign bodies, prostheses, or pacemakers.
utilizes magnetic energy to align protons
T1 - spin lattice time
(time required for 63% of protons to realign with the magnetic field)
-CSF and vitreous appear dark (high water content) and white matter white (high fat
content)
-orbital lesions generally are dark on T1 except blood, melanin, and mucus
T2 - spin-spin relaxation time
(time required for 63% of protons to relax with the plane perpendicular to the magnetic
field)
-image opposite to that of T1
III. Visual system
A. Visual pathway
Retinocortical pathway
retina --> ON --> optic chiasm (decussation of nasal retinal fibers)--> optic tract --> LGB
--> optic radiations --> occipital cortex
B. Visual fields
1. Nerve fiber bundle defects (unilateral scotomas)
a. papillomacular bundle
central scotoma
centrocecal scotoma
paracentral scotoma
b. arcuate nerve fiber bundle
Bjerrum scotoma
Seidel scotoma
Rhonne scotoma
Nasal step
c. nasal nerve fiber bundles
Wedge shaped scotomas at temporal visual field
2. Optic nerve
-unilateral
-scotoma always extends from the blind spot
-respects the nasal horizontal meridian
3. Optic chiasm
-bitemporal hemianopia respecting vertical meridian
4. Optic tract
-contralateral homonymous hemianopia
-respects vertical midline (all homonymous visual field defects do)
-incongruous
5. Lateral geniculate body
-rare
-incongruous homonymous hemianopia
-homonymous horizontal sectoranopia
6.Optic radiations
a. Meyer’s loop (temporal lobe)
-pie in the sky field defect, contralateral homonymous upper quadrantanopia
b. Parietal lobe
-inferior homonymous quadrantanopia/ hemianopia
7. Occipital lobe (visual cortex)
-congruous
-respects vertical midline
-hemianopic paracentral scotoma
-lesion at posterior segment(tip) of occipital lobe
-etiology blunt trauma or severe hypotension (watershed area)
-homonymous hemianopia with macular sparing
due to dual blood suply (post. cerebral and middle cerebral a.) with occlusion of post.
cerebral.
- homonymous hemianopia with macular splitting
-more common
-bilateral homonymous hemianopia with macular sparing
-produce constricted visual field
C. Disorders of visual integration
Alexia
-inability to read despite normal vision
-requires processing of visual information from the occipital cortex to the angular gyrus
located in the dominant parietal lobe
-alexia with agraphia results from a lesion affecting the angular gyrus
-alexia without agraphia results from a large occipital lesion in the dominant hemisphere
which extends to the splenium curtailing flow of infromation from the intact contralateral
visual cortex to the dominant hemisphere angular gyrus.
Visual neglect
-patient ignores one side of visual space
-usually occurs from right parietal lobe lesions
Agnosia
-inability to recognize objects by sight
-results from lesions of the inferior occipitotemporal area
Prosopagnosia
-inability to recognize faces
-results from bilateral inferooccipital lesions
Cerebral achromatopsia
-color blindness in one hemifield
-lesion in inferior occipital area
Visual hallucinations
Release type
-occurs in blind individuals
-due to lack of input to visual association areas
-may be formed or unformed hallucinations
Ictal type
-streotyped and paroxysmal
-formed (temporal lobe)
-unformed (occipital lobe)
Palinopsia
-abnormal perseveration of visual images
-usually associated with other neurologic symptoms
-tend to involve the right hemisphere occipito-parietal convexity
IV. Pupillary disorders
A. Pupillary light reflex pathway
photoreceptors --> retinal ganglion cell axons --> pretectal nucleus --> pretecto-
oculomotor tract --> bilat. Edinger Westphal nuclei --> CN III --> ciliary ganglion -->
iris sphincter & ciliary body
B. Afferent pupillary defect
-elicited by swinging flashlight test
-normal pupillary response is constriction followed by slight redilation
-abnormal response is decreased or absent constriction with redilation or redilation that is
larger than when light is swung to other eye.
-indicator of optic nerve disease which causes light to appear dimmer in the affected eye
than in the opposite eye.
-also seen in extensive retinal disease (eg. large RD), brunescent cataract, and some
amblyopes (up to 0.6 log unit density defect)
C. Anisocoria
Definition - unequal pupillary size
1. Physiologic
-most common cause of anisocoria
-pupillary size difference less than 1 mm and varies from day to day
-more common in elderly patients
2. Third nerve palsy
-anisocoria (mydriasis) associated with ptosis and ocular motility disturbance seen in
intracranial aneurysms (ICA/Post. comm. a.)
-isolated anisocoria may be seen with uncal herniation or basal meningitis
-anisocoria during eye movement seen in aberrent regeneration of CN III
3. Traumatic/surgical
-damage to pupillary sphincter
4. Pharmacologic
-caused by mydriatic or miotic agents
5. Adie’s tonic pupil
-characterized by sluggish and segmental constriction to light and better response to
near
-caused by post-ganglionic parasympathetic lesion
-80% initially unilateral and more common in females (70%)
-supersensitivity to diluted pilocarpine (0.05% - 0.1%)
-Holmes-Adie syndrome if diminished deep tendon reflex and orhtostatic hypotension
also present
6. Horner’s syndrome
-miosis, ptosis, anhydrosis, and apparent relative enophthalmos (heterochromia in
congenital cases)
-caused by sympathetic lesion (pre or post-ganglionic)
First order - CNS lesion caused by stroke or tumor
Second order - caused by cervical disc disease or trauma to C-spine, apical lung tumors
(Pancoast syndrome), tumors metastatic to cervical lymph nodes, chest surgery, thoracic
aortic aneurysms, trauma to brachial plexus.
Third order - caused by intracranial diseases including migraine (Raeder’s syndrome Type
II) and cavernous sinus inflammatory (Tolosa-Hunt syndrome), traumatic (carotid-
cavernous fistula) and neoplastic (meningioma, metastasis, lymphoma) diseases.
-no dilatation with topical cocaine (4% - 10%)
-pre and post-ganglionic Horner’s differentiated with Paredrine 1%
(hydroxyamphetamine) test
pre-ganglionic dilates
post-ganglionc does not dilate
D. Light -near dissociation
Argyll-Robertson
-characterized by small irregular pupils that do not react to light but react with
accomodation
-seen in tertiary syphillis
-lesion in midbrain (Parinaud’s syndrome)
Adie’s tonic pupil (see above)
Parinaud syndrome
-mid position pupils with poor light response and intact near response
-associated with verical gaze paresis, nystagmus, and lid retraction with scleral show
above limbus; convergence-retraction (of globe) nystagmus
-lesion in dorsal midbrain
Aberrent regeneration of CN III
Amaurotic pupils or afferent pupillary defect from sub-total visual loss due to optic nerve
or severe retinal disease or brunescent cataract.
V. Optic nerve disorders
A. Optic disc edema
1. Features
elevated nerve head
narrowing of cup with relative preservation of cup depth
edema of nerve fiber layer obscuring underlying disc margin
retinal (Paton’s lines)/choroidal fold
hyperemia
venous congestion
peripapillary hemorrhage (most commonly flame)
cotton wool spots
hard exudates
2. Papiledema v. papillopathy
Papilledema
-due to raised intracranial pressure
-bilateral, may be quite asymmetric in degree
-generally normal visual acuity and fields early in the course
Papillopathy
-due to optic nerve disease (eg. inflammatory & vascular)
-severe decrease in visual acuity and/or visual field loss
3. Pseudotumor cerebri
-characterized by headache, diplopia (“false localizing CN VI palsy”), pulsatile tinnitus,
and transient visual obscurations
-typically seen in young obese females
-exam shows raised intracranial pressure, normal CSF, and normal CT/MRI
-etiology unknown but can occur in COPD, radical neck dissection, corticosteroid use or
withdrawal, with elevated levels of Vit. A (renal failure), tetracycline, lithium, and
nalidixic acid.
-initial treatment is weight loss followed by use of Diamox or Lasix to reduce
intracranial pressure.
- a short course of high dose steroids may be useful in cases of acute visual loss from
severe papilledema.
-surgical treatments for refractory cases are optic nerve decompression and lumbar-
peritoneal shunt.
-need to follow visual field, preferably Goldmann type dynamic. The earliest loss is
outside the Bjerrum region beyond area tested by automated perimetry. Acuity, contrast
and color are last to go in decompensated papilledema.
4. Optic neuritis
-subacute loss of vision associated with retrobulbar pain that worsens with ocular
movement. (Mean evolution time is 3-5 days in contrast to sudden vision loss in ishcemic
optic neuropathy).
-usually affects young women (15-45 y.o.) and symptoms are unilateral (except in
children)
-exam shows decreased visual acuity, decreased color vision, RAPD,decreased
brightness sentistivity, and visual field defects (diffuse, central, paracentral, arcuate, and
altitudinal)
-2/3 of cases show normal optic disc (retrobulbar neuritis)
-1/3 show optic disc swelling (papillitis)
-MRI shows gadolinium enhancement of the optic nerve and often foci of demyelination
in the CNS. Presence of >2 plaques increses risk of developing clinically definite MS
within 2 years (up to 39%).
-decrease in vision stabilizes after 1 week and gradually improves in several months.
Visual recovery of 20/40 or better occurs in 95% of patients within 1 yr without
treatment.
-50% of recovered patients may develop transient decrease in vision after exercise or
elevation of body temperature (Uhthoff’s phenomenon).
-long-term risk of developing MS is greater than 60%
-recommended treatment from the Optic Neuritis Treatment Trial (ONTT) study is IV
methylprednisolone (250 mg qid x 3d) followed by oral prednisone (1mg/kg/day x 11
days) which hastened visual recovery (slightly) and reduced rate of development of MS
within 2 years in patients with 2 or more demyelinating foci. However, final visual acuity
is not improved by treatment and rate of development of MS after 3 years is the same as
placebo.
-differential diagnosis of optic neuritis
central serous retinopathy big blind spot syndrome
multiple evanescent white dot syndrome anterior ischemic optic neuropathy
syphilitic optic neuritis postviral optic neuritis
Leber hereditary optic neuropathy toxic/ nutritional optic neuropathy
(mitochondrial gene mutations)
malignant optic glioma
5. Ischemic optic neuropathy
A. Arteritic
-narrowing and thrombosis of posterior ciliary artery due to temporal arteritis (a.k.a. giant
cell arteritis)
-presents as acute loss of vision with cranial and systemic symptoms (headache, jaw
claudication, fever, weight loss, or malaise)
-affects women more than men (2:1)
-always occurs after age 55
-exam shows severe visual loss (acuity 20/200), partial disc swelling with nerve fiber
layer hemorrhage, and altitudinal field defects (usually inferior and large). Contralateral
eye may show small cup to disc ratio.
-no effective medical or surgical therapy
-clinical course shows partial recovery of vision of 3 or more lines within 6 months in
43% of cases.
-recurrence rare but involvement of contralateral eye occurs in 25% by 3 years and up to
50% by 10 years.
-unlike vascular occlusive diseases, life expectancy is normal
C. Posterior ischemis optic neuropathy
-ischemic damage to retrobulbar optic nerve
-often bilateral and simultaneous
-rare condition which occurs in setting of severe hypotension or anemia (eg. massive
bleeding) or vasculitis (Hayreh).
-treatment is IV fluids and blood transfusion and surgical correction of bleeding site.
6. Multiple evanescent white dot syndrome
-idiopathic disorder which presents as acute unilateral loss of vision (mild to severe)
-affects young individuals, females more than males, in association with flu symptoms
-exam shows decreased visual acuity (20/25 - 20/200), blurring of optic disc, and
characteristic small white dots (100-200 µm) at level of RPE located perifoveally. Mild
sheathing, cells in vitreous, macular granularity, and flame hemorrhages may also be
present on fundoscopic exam.
-fluorescein angiogram shows early hyperfluorescence of the dots with late staining and
mild leakage.
-ERG shows depressed a and b waves on acute sage of the disease but normalizes with
visual recovery
-clinical course self-limited and visual recovery usually achieved by 8 weeks.
7. Infiltrative optic neuropathy
-loss of vision due to infiltration of the optic nerve by malignancy, inflammatory or
infectious proceses
leukemias, plasmacytosis, multiple myeloma, sarcoidosis, TB, cryptococcus,
toxoplasmosis, toxocariasis, CMV, and coccidiodomycosis
8. Diabetic papillopathy
-occurs in juvenilie insulin-dependent DM
-sudden decrease in vision with bilateral disc edema and visual field defect (enlarged
blind spot and arcuate field defects)
-no ischemia on fluorescein angiography
-clinical course shows full visual recovery in 3 months to a year.
9. Dysthyroid optic neuropathy
-occurs in Graves disease
-progressive loss of vision due to compression of optic nerve by surrounding enlarged
extraocular muscles at the orbital apex.
-may be unilateral or bilateral
-exam may show swollen or normal optic disc (pale in late stage) and visual fiel defect
(central or arcuate scotoma)
-treatment options are corticosteroids, surgical decompression of the orbit, or radiation
10. Papillophlebitis (Big blind spot syndrome)
-presents as mild decrease in vision (unilateral) in young healthy adults
-exam shows disc edema but no APD. Retinal veins may be engorged with retinal
hemorrhages.
-visual field testing shows big blind spot
-clinical course self-limited with full recovery by 1 year.
11. Miscellaneous causes
uveitis, central retinal vein occlusion, malignant HTN, and hypotony
12. Pseudopapilledema
Optic nerve drusen
-deposits of calcium, mucopolysaccharides, hemosiderin and amino acids in the optic
nerve head
-fundoscopically it appears as irregular, glistening white globules which autofluoresce
-usually bilateral (75-80%) and occurs predominantly in caucasians
-inherited as autosomal dominant
-may be associated with retinitis pigmentosa
-generally asymptomatic, but may produce visual field loss by direct effect on optic nerve
axons, subretinal hemorrhage, or subretinal neovascularization.
-exam shows absence of central cup and elevated disc margins but distiguished from disc
edema by presence of venous pulsations and abscence of hemorrhages, exudates, cotton
wool spots, and Paton’s lines.
-visual field testing shows enlargement of the blind spot, nerve fiber bundle defects, and
constriction of the peripheral field.
Tilted optic disc
-one side displaced posteriorly and the other anteriorly.
-crescent on side of disc depression
-retinal vessels are directed obliquely
-seen in high myopic patients
Optic nerve hypoplasia
-unilateral or bilateral small disc
-has double ring sign (concentric choroidal-retinal pigment changes)
-etiology unknown but increased incidence in children of mothers taking LSD, anti-
seizure medications, quinine, and ETOH abuse.
-may be associated with intracranial tumors and endocrine abnormalities.
B. Optic atrophy
1.Compressive
a. Optic nerve glioma
-most common cause of orbital tumors in children (20%)
-50% intraorbital and 50% intracranial
-10-50% have neurofibromatoses
-present as progressive visual loss with strabismus, nystagmus, and proptosis
-exam shows optic disc swelling initially, then pallor and APD
-CT/MRI shows fusiform thickening and kinking of the optic nerve
-very slow growing tumor but occasionally extends to the optic chiasm and contralateral
optic nerve
-surgical resection not recommended due to slow growth and concept that they are
multicentric in origin, hence not cured by removal
-chemotherapy and radiation therapy are possible treatments
b. Malignant optic glioma (glioblastoma multiforme)
-rare form of optic nerve glioma seen primarily in adults
-presents with unilateral partial loss of vision followed by involvement of contralateral
eye
-complete blindness in 2-4 months
-death in 3-9 months
c. Optic nerve meningioma
-represents 5% of orbital tumors
-more common in women than men (3:1) and generally affects adults (40-50 y.o.)
-signs and symptoms are decreased vision, proptosis, optic disc atrophy, and opticociliary
shunt vessels
-CT/MRI shows abnormal enhancement of the nerve periphery (railroad track sign) and
enlargement of the optic canal
-slow growing tumor with rare intracranial extension but may increase in size during
pregnancy
-not surgically resectable but may respond to radiation therapy
d. Pituitary adenoma
-may cause hypo or hyperpituitarism
-most common type is prolactinoma (30.5%) followed by non-functional tumors (23%),
growth hormone (17%), adrenocorticotropin (14%), mixed GH-prolactin (9.5%),
gonadotropin (2.5%), and thyrotropin ( 40 y.o.)
-self-limited and resolves in 12 weeks
7. Aberrent regeneration of CN III
Pseudo von Grafe sign
-lid retraction with downgaze
-due to innervation of levator palpebrae by IR fibers
Inverse Duane’s syndrome
-lid retraction with adduction
-due to innervation of levator palpebrae by MR fibers
Pseudo-Argyll-Robertson pupil
-light-near dissociation
-due to innervation of pupillary sphincter by MR fibers
Pupillary constriction on downgaze
-due to innervation of pupillary sphincter by IR fibers
B.CN IV
1. Nucleus
-located at periaqueductal gray matter of midbrain
-innervates contralateral superior oblique
-lesion produces hypertropia causing vertical diplopia as well as ex-cyclotorsion (12:00
position toward the ear)
-ipsilateral Horner’s syndrome may also be present due to adjacent descending
sympathetic fibers in dorsal midbrain
-etiology includes hemorrhage, infarction, demyelination and trauma/surgery
2. Fascicle
- courses dorsocaudally and decussates at anterior medullary velum prior to exiting at
level of inferior colliculus
-susceptible to injury by compression (eg. severe head trauma or pinealoma) resulting in
bilateral CN IV palsy
-Bielschowsky test may be negative and requires double Maddox rod test for diagnosis
(>10° of excyclotorsion)
3.Subarachnoid course
-long intracranial course traversing dorsal to ventral along the tentorial edge
-highly susceptible to injury from neurosurgery and head trauma
-lesion produces ipsilateral CN IV palsy (or bilateral if anterior medullary velum
involved)
4.Cavernous sinus
-located in lateral wall below CN III and above CN V
-lesion produces multiple CN palsy (III, IV, V, VI) and Horner’s syndrome
5. Orbit
-enters via the superior orbital fissure to innervate the SO muscle
-CN IV can be affected in orbital apex syndrome
6. Congenital CN IV palsy
-represents 29% - 67% of fourth nerve palsy
-seen most commonly in children but can decompensate later and may present in adults
(50-70 y.o.)
-exam shows large vertical fusion amplitude (>3D)
-old photographs showing head tilt help make diagnosis
C. CN VI
1.Nucleus
-located at the floor of the fourth ventricle below facial colliculus (fibers if CN VII loop
over nucleus of CN VI)
-contains motor neurons that innervate LR but also interneurons that project ot
contralateral MR subnucleus via medial longitudinal fasciculus (MLF)
-lesion results in conjugate horizontal gaze palsy
-Duane’s syndrome
-congenital absence of abduscens nucleus
-LR innervated by branches of CN III
-defective abduction and narrowing of palpebral fissure from globe retraction with
adduction
-usually does not complain of diplopia
-Mobius syndrome
-congenital absence of abduscens and facial nuclei
-may also involve CN IX and XII nuclei
2. Fascicle
-courses ventrally and laterally to exit at the pontomedullary junction
-lesion usually affects other nearby structures
-Millard-Gubler sybdrome
-involvement of the pyramidal tract
-ipsilateral CN VI palsy with contralateral hemiplegia
-Foville’s syndrome
-involvement of CN VII nucleus/fasciculus, spinal tract of CN V, and sympathetic fibers
-horizontal conjugate gaze palsy, facial weakness and numbness, and Horner’s syndrome
3. Subarachnoid course
-courses upward along the clivus and is susceptible to injury by tumors, basal skull
fracture, trauma, raised intracranial pressure (“false-localizing CN VI palsy”)
4. Petrous pyramid
-CN VI passes through Dorello’s canal which is bounded by the petrous bone and
petroclinoid ligament
-susceptible to injury from petrous bone fracture, tumors, and infectious/inflammatory
processes of the middle ear
-Gradenigo syndrome
-ipsilateral CN VI palsy, with decreased hearing, facial pain and facial paralysis
-due to abscess formation in petrous apex following otitis media
-Pseudo-Gradenigo syndrome
-similar symptoms as Gradenigo’s syndrome but due to nasopharyngeal CA or
cerebellopontine angle tumors
5. Cavernous sinus
-accompanied by post-ganglionic sympathetic fibers
-lesion produces multiple CN palsy (III, IV, V, VI) and Horner’s syndrome
6. Orbit
-enters via the superior orbital fissure to innervate the LR
-can be involved in orbital apex syndrome
7. Isolated CN VI palsy
-post viral
-seen commonly in young patients (55 y.o.) esp. with DM and HTN
-self-limited with recovery occuring by 6-8 weeks
D. Multiple cranial nerve palsy
1. Cavernous sinus syndrome
-cavernous sinus is a dural venous sinus which contains the internalcarotid a., CN III,
CN IV, CN V, CN VI, and oculosympathetic fibers
-lesion in the cavernous sinus causes painful ophthalmoplegia, facial numbness, and
Horner’s syndrome
-various etiology
a. internal carotid artery aneurysm
b. carotid-cavernous fistula
c. cavernous sinus thrombosis
d. neoplasm
e. inflammation (Tolosa-Hunt syndrome)
2. Orbital apex syndrome
-crowding of intraorbital contents due to tumor, inflammation, infection, or edema from
trauma which causes injury to CN II, CN III, CN IV, CN V 1,2, and CN VI
-presents as proptosis, chemosis, ophthalmoplegia (paresis or mechanical restriction)
and decreased visual acuity.
3. Myasthenia gravis
-an auto-immune disease with formation of antibodies against acetylcholine receptors
-presents as ptosis and diplopia which fluctuates and varies from day to day
-ptosis is asymmetric and worsens after prolonged upward gaze. Manual elevation of
more ptotic lid results in greater ptosis of the fromer less ptotic lid due to Hering’s law.
-diplopia pattern is variable and may appear as cranial nerve paresis, supranuclear
motility disorder, or complete ophthalmoplegia
-associated systemic symptoms weakness and fatigue, dysphagia, hoarseness of voice,
dysarthria, and dyspnea
-diagnostic tests include
a. Tensilon test
-test dose of 2 mg edrophonium chloride (Tensilon) is injected followed by 8 mg slowly
injected starting 1 minute later
-positive test if ptosis and ocular motility improves
-common side effects include diaphoresis, lacrimation, abdominal cramping, nausea,
vomiting, salivation, syncope
-rare but serious complications include bradycardia and respiratory arrest
-antidote is atropine sulfate (but symptoms are usually over by the time this can be
administered)
b. Sleep test
-patient rests and closes eyes for 30 minutes
-positive test if ptosis and ocular motility improves after rest period
c. Ice pack test
-ice pack is placed over closed eyes for 2 minutes
-ptosis improves because neuromuscular transmission is enhanced in the cold
4. Multiple sclerosis
-autoimmune disorder causing demyelination of the CNS
-affects primarily young adults (25-40 y.o.) and women greater than men (2:1)
-incidence increases with increasing latitude from the equator
-presents as multifocal neurologic deficits separated by space and time
-may present as myriad of neuro-opthalmologic deficits but commonly manifests as optic
neuritis,bilateral INO, CN VI or CN VIII palsy, and nystagmus
-MRI shows demyelinating plaques
-corticosteroids used for acute attacks
-interferon and other immunomodulators being investigated for long-term treatment
5. Thyroid ophthalmopathy
-causes inflammation of extraocular muscles thereby impairing/restricting motility
6. Chronic progressive external ophthalmoplegia
-usually presents as bilateral asymmetric ptosis before adolescence which progresses to
external opthalmoplegia
-rare diplopia due to symmetric nature
-may have weakness of orbicularis, facial muscles, arms legs, and chewing
-etiology is mitochondrial abnormality in extraocular muscles
-serum CK may be elevated
-EM shows ragged red fibers seen on H&E to be abnormal aggregates of malformed
mitochondria
7. Botulism
-cholinergic blockade due to botulinum toxin
-may be acquired from food, wound infection or birth
-ocular findings include ophthalmoplegia, ptosis, and dilated poorly reactive pupils
-systemic symptoms are nausea vomiting, and generalized weakness
E. Supranuclear gaze palsy
Gaze centers
Horizontal
CN VI / pontine paramedian reticular formation (PPRF)
Vertical
rostral interstitial nucleus of the MLF (RiMLF)
interstitial nucleus of Cajal
Supranuclear inputs
Visual
calcarine cortex
superior colliculus
Non-visual
frontal eye field
vestibular system (semicircular canals)
Horizontal gaze disorders
1.Internuclear ophthalmoplegia (INO)
-lesion in MLF disconnecting ipsilateral CN III, medial rectus subnucleus from
contralateral CN VI / PPRF
-results in inability to adduct the eye ipsilateral to the lesioned MLF with nystagmus of
contralateral abducting eye
-usually orthophoria in primary gaze
-etiology
MS, vertebrobasilar insufficiency, AVM, tumors, and inflammatory diseases
(INO is thought to be uncommon from brainstem vascular disease since there is
collateral flow to the dorsal brainstem from long circumferential vessels and most
lacunes occur in the ventral brainstem in the distribution of the short penetrating arteries
medially.)
2.WEBINO
-walleyed bilateral INO
-exotropia in primary gaze with inability to adduct either eye past midline
-rostral MLF lesion with involvement of CNIII nucleus
3. Unilateral horizontal gaze palsy
-lesion of CN VI nucleus and/or PPRF or supranuclear pathways from contralateral
cerebral hemisphere
4. One and a half syndrome
-lesion of CN VI nucleus / PPRF and ipsilateral MLF
-ipsilateral conjugate gaze palsy
-contralateral INO
5. Fisher syndrome
-variant of Guillain-Barre that involves only brainstem and cranial nerves
-results in unilateral or bilateral ophthalmoplegia with ataxia and areflexia
-self-limited and usually follows a viral illness
CSF examination shows elevated protein but no pleocytosis
Vertical gaze disorders
1. Tonic deviation
-upward oculogyric crises occurs in post-encephalitic Parkinsons’s disease
-can also be seen in comatose patients
-tonic upgaze indicates bilateral cerebral/cerebellar lesions
-tonic down gazeindicates bilateral thalamic bleed or infarct
-tonic downgaze can also occur in metabolic encephalopathy
2. Parinaud’s syndrome
-lesion in dorsal midbrain
-characterized by
- supranuclear paresis of vertical gaze with intact vestibular-ocular reflexes
-ptosis
-light-near pupillary dissociation
-skew deviation
-convergence retraction nystagmus
-etiologies
congenital aqueductal stenosis
pinealoma
head trauma
vascular formation
long standing multiple sclerosis
basilar CVA
3. Progressive supranuclear palsy
-progressive conjugate paresis of gaze which presents initially as decreased downgaze
-also exhibits nuchal rigidity and seborrhea as in Parkinson’s disease but no resting
tremor and head is retracted rather than bent forward as in Prkinson’s disease (simian
posture)
-has OKN “drift sign”, normal Doll’s eye, and normal Bell’s response
-associated with progressive dementia and death usually in 5 years
4. Downgaze palsy
-rarely isolated
-lesion in RiMLF rostral to CNIII and dorsomedial to red nucleus
5. Skew deviation
-lesion in internuclear connections involved in vertical gaze
-produces ipsilateral hypotropia in lower brainstem lesion
-ipsilateral hypertropia in pontine and midbrain lesions
F. Miscellaneous causes of monocular diplopia with full motility
Astigmatism
Cataracts
Peripheral iridectomy
Macular disease
VII. Nystagmus
A. Definition
-rhythmic involuntary oscillations of the eye or eyes in which the abnormality results in a
slow drift from fixation
-pendular nystagmus has slow phases in both opposing directions
-jerk nystagmus has opposing slow and fast phases and the direction of jerk type
nystagmus is designated towards the fast phase
B. Physiologic nystagmus
1. End-position
-fine nystagmus at extreme horizontal gaze which resolves upon return to primary
position
2. Optokinetic (OKN)
-combination of pursuit and reversesaccade in an attempt to fixate a succession of
moving targets on the fovea
-requires intact visual system and therefore very useful for testing functional visual loss.
However, it does not correlate with visual acuity since motion detection is all that is
needed.
-asymmetric OKN may be seen in homonymous hemianopia from deep parietal lobe
lesions but OKN is spared with medial occipital lesions (usually infarction) causing
hemianopia
3. Caloric
-nystagmus elicited by stimulation of endolymph movement in semicircular canals using
warm and cold stimuli, respectively
-Cold Opposite Warm Same (COWS) refers to the direction of the slow phase deviation
induced by caloric stimulation of one ear
-useful in testing brainstem function in comatose patients
4. Rotational
-stimulation of vestibulo-ocular reflex
-eyes deviate opposite to the direction of movement with nystagmus towards the direction
of movement
-useful in evaluation of oculomotor system (esp. CN VI integrity) in infants
C. Congenital nystagmus
-nystagmus present since birth but may not be noticed by family until surprisingly late in
age in first affected sibling
-usually horizontal and uniplanar
-increases with fixation and decreases with convergence
-inversion of the OKN
-associated with high astigmatism
-may present with head turn in attempt to keep eyes in null zone (gaze position at which
nystagmus is least and visual acuity is best)
D. Latent nystagmus
-form of congenital nystagmus that is present only when one eye is covered
-exhibits jerk nystagmus with fast phase directed away from covered eye
-visual acuity decreased during monocular testing due to nystagmus
E. Spasmus nutans
-triad of torticollis, head nodding, and nystagmus, often monocular
-usually begins within first year of life and resolves spontaneously
-normal visual acuity and fundus exam
-need to rule out suprasellar/hypothalamic pathology with MRI if any ocular
abnormalities are present
F. Upbeat nystagmus
-nystagmus present in primary position
-usually indicates brainstem lesion
G. Downbeat nystagmus
-nystagmus present in primary position but increases with lateral gaze
-associated with lesions in cervicomedullary junction
CVA, multiple sclerosis, spinocerebellar degeneration, and Arnold-Chiari malformation
H. See-saw nystagmus
-rotary and pendular type of nystagmus
-one eye intorts and rises while other eye extorts and falls
-associated with bitemporal hemianopia in large parasellar tumors
-often with INO
-other causes include CVA, trauma, albinism, retinitis pigmentosa, and optic nerve
hypoplasia
I. Convergence-retraction nystagmus
-cocontraction of two or more opposing horizontal muscles, usually aggravated or
precipitated on attempted upgaze
-component of Parinaud syndrome
K. Vestibular nystagmus
Peripheral vestibular nystagmus
-lesion in vestibular end organ or CN VIII
-nystagmus is rotary, unidirectional and uniplanar
-amplitude greatest when gaze towards fast component (Alexander’s law)
-associated with vertigo, tinnitus, and deafness
-possible causes are labyrinthitis, ischemia, trauma, and toxins
Central vestibular nystagmus
-lesion in brainstem (CN VIII nucleus or connections)
- nystagmus may be uni or bidirectional
-may be vertical, horizontal or rotary and may change direction with gaze
-possible causes are trauma, CVA, tumor, and demyelination
J. Periodic alternating nystagmus
-horizontal jerk nystagmus which switches from one side to the other with cycle time of
60-90 seconds; null point cycles slowly from side to side
-may have associated skew deviation and downbeat nystagmus
-possible causes are congenital, vestibulo-cerebellar diseases, and acquired bilateral
visual loss
-need MRI to rule out Arnold Chiari malformation, cerebellar atrophy, or posterior fossa
mass
-treatment is Baclofen
VIII. Facial nerve disorders
A. Pathway
precentral motor cortex (frontal lobe) -->corticobulbar tract -->*CN VII nucleus -->CN
VII nerve --> facial muscles
*CN VII nucleus receives bilateral input for upper face but only contralateral input for
lower face innervation
B. Supranuclear facial palsy
-results in contralateral weakness of lower two thirds of face with sparing of forehead
-eyelid closure usually only mildly affected
-etiology commonly CVA but may be from any cerebral lesion (hemmorhage, tumor, etc.)
C. Facial nerve palsy
-results in ipsilateral weakness of both upper and lower portions of the face
-impairs closure of the eyelids and results in exposure keratopathy
Etiology
1. cerebellopontine angle tumor (eg. acoustic neuroma)
-associated with hyperacusis, decreased taste, and involvement of CN V, VI, or VIII
2. Ramsay-Hunt syndrome
-herpes zoster in CN VII and CN VIII
-diagnosed by finding by vesicles in external auditory canal, typanic membrane or
external ear pinna
-accompanied by severe pain and postherpetic neuralgia
-less chance for recovery compared with Bell’s palsy
3. Bell’s palsy
-most common cause of facial paralysis
-etiology unknown but thought to be auto-immune, viral induced inflammation or
ischemic injury
-typically affects adults with sudden onset of facial paresis
-may be associated with decreased tearing, taste and dysacusis, and usually pain behind
the mandible
-84% show spontaneous recovery, but aberrent regeneration may be present (eg. crocodile
tears)
-treatment is oral corticosteroids to reduce nerve edema and consequent damage
4. trauma/surgery
5. sarcoidosis
-often bilateral
-Heerfordt’s syndrome of “uveoparotid fever” combines uveitis, fever, parotid swelling
and CN VII palsy
6. Lyme disease
D. Essential blepharospasm
-bilateral episodic contraction of orbicularis oculi
-the movement mimics normal blinking or voluntary eye closure
-usually occurs at age 40-60
-may be associated with facial grimacing (Meige syndrome), cogwheeling and other
extrapyramidal signs
-etiology is unkown but may be due to lesion in basal ganglia
-treatment is injection of botulinum toxin which provides temporary relief
-neuroleptic drugs are not effective
E. Hemifacial spasm
-unilateral episodic clonic spasm of the face
-initially starts with twitching of orbicularis oculi then progressively involves all facial
muscles in time
-etiology may be compression of CN VII by vessels or tumors but majority of cases are
idiopathic
-medical treatment includes carbamazepine, clonazepam, baclofen, and botulinum toxin
-surgical treatment includes facial myectomy, neurectomy, and neurosurgical
decompression of CN VII from blood vessels
F. Facial myokymia
-unilateral fibrillation of facial muscles
-usually begins at orbicularis oculi and spreads to entire facial muscles
-etiology pontine glioma in children and multiple sclerosis in adults
-treatment includes carbamazepine or phenytoin
IX. Headache
A. Muscle tension
-most common cause of chronic headaches (90%)
-described as tension or tightness around frontal and occipital areas
-associated with emotional or physical stress
-treatment is NSAIDS and tricyclic anti-depressants (TCA)
B. Migraine
-repetetive attacks of throbbing headache which is worsened by light and loud noises, and
usually relieved by sleep;commonly associated with nausea, vomiting, diaphoresis and
pallor
-headache usually alternating from one side to another and lasts several hours
-may or may not be preceded by an aura
-classic aura is a slowly migrating scotoma bounded by a zigzag shimmering light which
can progress to transient loss of vision followed by a headache
-positive family history of migraine headaches
-more common in women than men
-treatment includes
-ergotamines, NSAIDS, serotonergic agents, and sumatriptan for acute attacks
-sumatriptan is contraindicated in patients with coronary artery disease or basilar artery
disease
-beta-blockers, calcium channel blockers, TCA, Prozac, valproic acid, and NSAIDS may
be used for prophylactic treatment
-also avoid specific things or events which have triggered migraines in the past (eg.
food, alcohol, perfume, or stress)
-migraine headaches that always recurr at the same site should be evaluated with
neuroimaging to rule out a mass lesion or vascular malformation.
C. Cluster headaches
-severe headaches in the distribution of external carotid a. (frontal or frontotemporal)
associated with Horner’s syndrome, epiphora, conjunctival injection, and rhinorrhea
-usually awakes patient from sleep unlike migraines
-more common in men than women (5:1)
-headaches occur in clusters and asymptomatic for months or years before recurrence
-difficult to treat but may respond to mehtysergide, sumatriptan, ergotamine, prednisone,
and calcium channel blocker
D. Intracranial tumor
-headache is progressive and worsens with bending or straining which increases
intracranial pressure; often wakens patient from sleep in ealry AM (migraine can do this
too)
-usually associated with neurologic deficits
E. Tic douloureux
-unilateral severe shock like pain in the distribution of trigeminal nerve (usually V 2 or 3)
lasting from seconds to minutes
-pain can be triggered by chewing, brushing teeth, or cold wind brushing the face
-pain can be so severe that it prevents patients from eating or drives them to suicide
-etiology may be vascular compresion of CN V, demyelinating disease or tumor in
posterior fossa
-needs MRI to rule out tumor
-medical treatment includes carbamazepine phenytoin, baclofen, clonazepam, and
valproic acid
-surgical treatment is decompression of CN V
F. Miscellaneous causes
temporal arteritis Sinusitis
TMJ syndrome Hypertension
Refractive error Intracranial bleed