Neuro ophthalmology 2016

NEURO
OPHTHALMOLOGY
UPDATE 2016
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DR DINESH MITTAL DR SONALEE MITTAL
DRISHTI EYE HOSP DF 63 SCHEME 74 C
VIJAYNAGAR INDORE INDIA

Neuro-Ophthalmic Anatomy
• Medical practice in general—and surgical
subspecialties in particular—are exercises in
applied anatomy. Although an adequate
understanding of physiology and, increasingly,
molecular genetics is important in understanding
disease and potential treatments, anatomy is the
foundation.

Skull Base
• The skull base is connected to
the lower facial skeleton by 3
sets of pillars formed by the
maxillary and zygomatic bones
anteriorly and the pterygoid
process of the sphenoid bone
posteriorly. Superiorly, the
vault of the skull is made up of
the parietal bones, which meet
at the sagittal suture; the
frontal bone, which adjoins
them at the coronal suture; as
well as the occipital bone,
which meets the parietal
bones at the lambdoid suture.

Anatomy Of Right Orbital Apex
• The optic foramen transmits the optic nerve,
ophthalmic artery, and oculosympathetic nerves.
• The superior orbital fissure, a gap between the greater
and lesser wings of the sphenoid bones, transmits CNs
III, IV, VI, V1, and the superior ophthalmic vein. Within
the lesser wing of the sphenoid bone is the optic
foramen, which leads to the optic canal. The optic strut
separates the optic canal from the superior orbital
fissure.
• The 4 rectus muscles arise from the annulus of Zinn.
CNs II, III (superior and inferior branches), VI, and the
nasociliary nerve all course through the annulus of
Zinn. CN IV and the frontal and lacrimal nerves and the
ophthalmic veins are located outside the annulus.

The medial orbital wall
• The medial orbital wall is
formed by 4 bones: maxilla
(frontal process), lacrimal,
sphenoid, and ethmoid. The
largest component of the
medial wall is the lamina
papyracea of the ethmoidal
bone. The anterior medial
orbital wall includes the
lacrimal sac fossa, which is
formed by both the maxillary
and lacrimal bones. The
lacrimal bone is divided by the
posterior lacrimal crest. The
anterior part of the lacrimal
sac fossa is formed by the
anterior lacrimal crest of the
maxillary bone.

Basal view of the brain showing the
anterior and posterior visual pathways

THREE
MAJOR
SENSORY
DIVISIONS OF
TRIGEMINAL
NERVE

Pupilloconstrictor light reflex
pathway

Pharmacological tests to localize
Horner’s syndrome

SUPRANUCLEAR AND
INFRANUCLEAR PATHWAYS
• Anatomical pathways, which extend from the cortical
centers of brain to the cranial nerve nuclei, are called the
supranuclear pathways. From the cranial nerve nuclei to
the ocular muscle exist the infranuclear pathways . In
peripheral nerves, the nerve starts from the brain and
reaches the anterior horn cell in the spinal cord. This is the
upper motor neuron. From the anterior horn cell of the
spinal cord, the nerve moves to the peripheral muscle. This
is the lower motor neuron. If there is a lower motor neuron
disease the limb is flaccid and if there is an upper motor
neuron disease the limb is spastic.

SUPRANUCLEAR AND
INFRANUCLEAR PATHWAYS
• The cranial nerve nuclei are like peripheral nerve
nuclei. From cortex of the brain the nerve extends to
the cranial nerve nuclei and this is the upper motor
neuron (UMN) pathway. From the cranial nerve nuclei
the nerve extends to the ocular muscle and this is the
lower motor neuron (LMN) pathway. In peripheral
nerves if the anterior horn cell gets involved as in
poliomyelitis, the patient has a LMN disease and so the
limb is flaccid. The anterior horn cell is akin to the
cranial nerve nuclei of cranial nerves. So, if the cranial
nerve nuclei gets involved the lesion produced will be a
LMN lesion.

The corticospinal and bulbospinal upper
motor neuron pathways.

Ocular Motor Cranial Nerves
• Without neural activity, the visual axes are usually
mildly to moderately divergent. The major tonic
input to ocular motility is supplied by 3 pairs of
ocular motor cranial nerves—CNs III, IV, & VI—that
innervate the 6 EOMs controlling ocular movement
. In addition, CN III innervates the levator
palpebrae superioris and the pupillary sphincter
muscles.

Ocular Motor Cranial Nerves
• Except for the inferior oblique muscle, the
innervation to each of the EOMs occurs
approximately one-third the distance from the
apex. The inferior oblique muscle receives its
innervation at approximately its midpoint from a
neurovascular bundle running parallel to the lateral
aspect of the inferior rectus muscle. All 6 EOMs
receive their innervation on the inside surface,
except for the superior oblique, where branches of
CN IV terminate on the upper (outer) surface of the
muscle.

Medical management of stroke
and TIA.

Neuro ophthalmology exam
• In ophthalmology, diagnoses are often made by visual clues.
While in neuro-ophthalmology, a thorough history is the
foundation of accurate diagnosis. While conversing with the
patient, note the following: gait, facial features, eyes, ocular
adnexa, hands, clothing, and mannerisms. After a detailed history
and physical examination the diagnosis is usually apparent.
• It is said that a neuro-ophthalmologist is a ‘thinking’ or ‘cognitive’
ophthalmologist. His aim is twofold:
• Localise lesion (Where)—Retina, optic nerve, optic chiasm, optic
tract, lateral geniculate body, optic radiation, occipital cortex
• Suspect the pathology (What)—VIN DITCH MD (Vascular,
Infectious, Neoplastic, Demyelinating, Inflammatory, Traumatic,
Congenital, Heredofamilial, Metabolic, Drug induced)

• When you come across a suspected neuro-
ophthalmic patient, set aside atleast 15-20 minutes
of the clinic time for a detailed history and
examination.
• Record the patient’s age, gender and occupation.
• Optic neuritis is generally seen in women between
20 and 40 years of age. Ischemic optic neuropathy
is mostly seen after the age of 40 years. Traumatic
optic neuropathy is more common in young males
riding two wheelers.

• Thyroid eye disease, myasthenia gravis, benign
intracranial hypertension, meningiomas and
multiple sclerosis are more common in females.
Craniopharyngioma, optic nerve glioma and
rhabdomyosarcoma are most commonly seen in the
pediatric population. Traumatic optic neuropathy,
intracranial and orbital foreign bodies, subdural
hematoma, intracerebral hemorrhage and
ophthalmoplegia are more common in the armed
forces and police due to the high incidence of
trauma.

CHIEF COMPLAINT
•It helps to ask the
patient—‘Tell me in one
sentence what your
problem is. Record the
chief complaint in the
patient’s own words.

Decreased Vision
• Transient visual loss (vision returns to normal within
24 hours, usually within one hour):
• Few seconds: Papilledema
• Few minutes: Amaurosis fugax, vertebrobasilar
insufficiency
• 10-60 minutes: Migraine (with or without subsequent
headache), Impending crvo , ischemic optic neuropathy,
carotid occlusive disease, CNS lesion, optic disc drusen,
giant cell arteritis.

Decreased Vision
• Visual loss lasting more than 24 hours
a. Sudden painless: Retinal artery or vein occlusion,
ischemic optic neuropathy, vitreous hemorrhage,
retinal detachment
b. Gradual painless loss: open angle glaucoma,
diabetic retinopathy, and compressive optic
neuropathy
c. Painful loss: acute angle closure glaucoma, optic
neuritis, uveitis

Color Vision
• Loss of Color Vision
• Optic neuritis, other optic neuropathies.
• Loss of Side Vision
• Right or left hemifield—stroke, pituitary tumor,
glioma,
• subdural hematoma, migraine
• Upper or lower hemifield—AION, optic neuritis
• Central—optic neuritis, toxic neuropathy

• Loss of Contrast of Vision
• Optic neuritis.
• Shaking of Objects (oscillopsia) or Eyes
• Acquired nystagmus (vertical or horizontal).
• Eye Pain (Orbital)
• Sinusitis, orbital pseudotumor, optic neuritis, diabetic
nerve palsy

Headache
• Malignant hypertension, increased
intracranial pressure, infectious CNS
disorder, giant cell arteritis, cerebral
tumor, aneurysm, subarachnoid
hemorrhage, epidural or subdural
hematoma, migraine, cluster headache,
tension, trigeminal neuralgia, Tolosa
Hunt disease, cervical spine disease.

Double Vision
• Binocular (Double vision is eliminated when either eye
is occluded).
• a. Typically intermittent: myasthenia gravis,
intermittent decompensation of existing phoria
b. Constant: Isolated sixth, third or fourth nerve palsy,
thyroid eye disease, inflammatory pseudotumor,
cavernous sinus superior orbital fissure syndrome,
post-trauma-blowout fracture, internuclear
ophthalmoplegia, vertebrobasilar insufficiency.

Eyelid
Drooping of Eyelid (Ptosis)
• Aging, myasthenia gravis, Horner’s syndrome, third
• nerve palsy, chronic progressive external ophthalmoplegia.
Lid Retraction
• Thyroid eye disease, midbrain syndrome.
Prominence of Eye (Proptosis)
• Thyroid eye disease, orbital cellulitis, pseudotumor,
• orbital tumors, trauma, varix, mucormycosis.

TENSILON TEST
Tensilon/Enlon (edophonium
hydrochloride) is available in India in
a multidose 10 mg/ml bottle

EVALUATION
•It is essential to evaluate
all cranial nerve functions
in a patient with
ophthalmoplegia or
seventh nerve palsy .

Oculomotor nucleus complex.
• all extraocular muscles
served by CN III are
innervated by their
respective ipsilateral
nuclei except the
superior rectus muscle.
Parasympathetic fibers
traveling to the
pupillary sphincter
muscle synapse in the
ciliary ganglion in the
orbit .

Oculomotor nerve (CN III)
• The nucleus of the oculomotor nerve (CN III) is located
dorsally within midbrain beneath aqueduct connecting
the third and fourth ventricles . The nuclear complex
itself represents a collection of subnuclei that have
specific identifiable functions . The fibers destined to
innervate the levator palpebrae superioris, medial
rectus, inferior rectus, pupil sphincter, and ciliary body
muscles exit ventrally ipsilateral to the individual
nuclei from which they originate. In contrast, the fibers
from the superior rectus subnucleus, which lies along
the midline, cross before exiting the brainstem to
innervate the superior rectus muscle.

• Unilateral supratentorial mass lesions may force the
uncus through the tentorial notch (uncal herniation) to
compress the ipsilateral CN III. Running forward in the
superior lateral wall of the cavernous sinus, the nerve
separates into a superior and an inferior division. These
divisions enter the orbit through the superior orbital
fissure within the annulus of Zinn. The superior division
runs forward intraconally to innervate first the superior
rectus muscle and then the levator palpebrae
superioris muscle. The inferior division sends
parasympathetic fibers to the ciliary ganglion in the
orbital apex approximately 10 mm anterior to the
annulus of Zinn and lateral to the optic nerve.

Lateral view of the course of CNs
III, IV, and VI.

• Within the ciliary ganglion, the fibers destined for
the pupillary sphincter and the ciliary body
synapse. The fibers subsequently accompany the
branch destined for the inferior oblique muscle.
There are 9–10 times as many fibers associated
with accommodation innervating the ciliary body
as there are fibers reaching the pupillary sphincter
muscle. This disparity may be one reason for the
development of light–near dissociation in Adie tonic
pupil . The remaining branches of CN III within the
orbit innervate the medial rectus and inferior
rectus muscles.

Oculomotor, Trochlear and Abducens Nerves
(3rd, 4th and 6th Cranial Nerves)
•In a third nerve palsy, the fourth
nerve can be assessed by looking at
a superior conjunctival vessel with
the naked eye or on the slit lamp
and asking the patient to look down
and nasally. The eye should intort
and the vessel should move down
and towards the nose .

COMPRESSIVE LESION INVOLVES PUPIL
• a compressive lesion of the third nerve
(particularly an aneurysm) will cause a
fixed, dilated pupil. In contrast, third
cranial nerve palsy from an ischemic
mononeuropathy (diabetes mellitus,
hypertension) demonstrates no
anisocoria and the pupil is briskly
reactive .

MANAGEMENT
• Consider checking blood pressure and ordering
laboratory studies (eg, CBC, fasting blood sugar,
hemoglobin A1C, ESR, and CRP) in patients with a
pupil-sparing third nerve palsy. ASPIRIN
PRESCRIBED ( USUALLY 75 MG TO 150 MG )
• The patient should be instructed to call if the
initially uninvolved pupil dilates or if there are new
signs or symptoms suggestive of an aneurysm.
• Atypical features for ischemic palsy should prompt
consideration for obtaining an MRI with MRA or CTA

Oculomotor, Trochlear and Abducens Nerves
(3rd, 4th and 6th Cranial Nerves)
• Immediate MRI to rule out mass/aneurysm is indicated for:
1. Pupil involving third nerve palsies
2. Pupil sparing third nerve palsies in:
a. Patients without diabetes or hypertension
b. Patients with incomplete third nerve palsies
c. Third nerve palsies over 3 months in duration,not
improving
d. Associated additional cranial nerve or neurologic
abnormalities.
3. All non-traumatic aberrant regeneration of third
nerve palsies.

Aberrant regeneration
• Aberrant regeneration may occur spontaneously
without preceding third nerve palsy in cavernous
sinus tumor or aneurysm. Signs of aberrant
regeneration in 3rd nerve palsy are:
• Pseudo Von Graefe’s sign Lid elevation on down
gaze
• Inverse Duane’s sign Lid elevation on adduction
• Pseudo Argyll Robertson pupil Pupillary
constriction on adduction, no reaction to light .

Fourth nerve
• The fourth (trochlear) cranial nerve supplies only
the superior oblique muscle.
• It is a very long and slender nerve, increasing its
vulnerability.
• It is the only cranial nerve to emerge from the
dorsal aspect of the brain. It is the only crossed
cranial nerve besides the optic nerve, innervating
the superior oblique muscle contralateral to its
nucleus.
• It has the fewest axons of any of the cranial
nerves.

Causes of isolated fourth nerve palsy
• Idiopathic lesions are common, and many of these
are thought to be congenital although symptoms
may not develop until decompensation occurs in
adult life due to reduced fusional ability. In contrast
to acquired lesions patients are not usually aware
of the torsional aspect, but may develop vertical
double vision that is often appreciated as of
sudden or subacute onset

Causes of isolated fourth nerve palsy
• Trauma frequently causes bilateral fourth nerve
palsy. The long and slender nerves are particularly
vulnerable as they decussate in the anterior
medullary velum, through impact with the tentorial
edge. Care must be taken not to mistake a bilateral
palsy for a unilateral lesion, particularly when
corrective surgery is contemplated.
• Microvascular lesions are relatively common, this
aetiology often being presumed when appropriate
systemic risk factors are present in the absence of
features of congenital onset.

Sixth nerve
• The nucleus of the sixth (abducens or abducent) nerve
lies at the mid-level of the pons, ventral to the floor of
the fourth ventricle. The fibres (fasciculus) leave the
brainstem ventrally at the pontomedullary junction.
• Nuclear lesion. A nuclear sixth nerve lesion also
causes a failure of horizontal gaze towards the side of
the damage due to involvement of the adjacent
horizontal gaze centre (paramedian pontine reticular
formation). Facial (seventh) nerve fibres wrap around
the sixth nerve nucleus, so ipsilateral lower motor
neurone (LMN) facial nerve palsy is also common.
Isolated sixth nerve palsy is never nuclear in origin.

Sixth nerve
• Foville (inferior medial pontine) syndrome is most
frequently caused by vascular disease or tumours
involving the dorsal pons. It is characterized by
ipsilateral involvement of the fifth to eighth cranial
nerves, central sympathetic fibres (Horner syndrome)
and horizontal gaze palsy.
• • Millard–Gubler (ventral pontine) syndrome involves
the fasciculus as it passes through the pyramidal tract
and is most frequently caused by vascular disease,
tumours or demyelination. As well as ipsilateral sixth
nerve palsy, there is contralateral hemiplegia and often
an ipsilateral LMN facial nerve palsy.

Treatment
• Observation with monocular occlusion or prismatic
(e.g. temporary Fresnel stick-on) correction of diplopia
is appropriate in idiopathic and presumed
microvascular lesions; up to 90% will recover
spontaneously, usually over weeks to several months.
Young children should be treated with alternate
patching to prevent amblyopia.
• Botulinum toxin injection into the ipsilateral medial
rectus may be used to prevent contracture, assess
residual function and sometimes to facilitate prismatic
correction with a large deviation ; it is rarely curative.
• Surgery should be considered only when adequate
time has been allowed for maximal spontaneous
recovery .

Summary
• Brain MRI (with or without orbital views) is
indicated in all patients with acute sixth nerve
palsies who have no known vascular risk factors.
• Management of a transient (eg, ischemic) sixth
nerve palsy may include temporary patching of the
eye or fogging of a spectacle lens with semiopaque
tape.
• Strabismus surgery may be the best option for
patients with chronic deviations who fail or are
• intolerant of conservative measures

Sensory and Facial
Motor Anatomy

Trigeminal Nerve (CN V)
• Although importance of CNs II, III, IV, and VI is
obvious, CN V and CN VII also have important
impacts on normal ophthalmic function and are
frequently involved in neuro-ophthalmic disorders.
For example, proper functioning of CN V is
essential for preventing corneal damage. In
addition, complete loss of corneal sensation may
be accompanied by abnormal corneal epithelial
growth (neurotrophic keratitis associated with loss
of neural secreted growth factors).

Lateral view of the orbit, showing
its sensory nerves

The 3 divisions of CN V synapse in
the trigeminal (gasserian) ganglion
• The ophthalmic division (V1) is the most anterior
branch exiting the trigeminal ganglion. It runs forward
within the lateral wall of the cavernous sinus just
below CN IV. As it approaches the superior orbital
fissure extradurally, it divides into 3 major branches:
lacrimal, frontal, and nasociliary. In addition, small
branches innervate the dura of the anterior middle
cranial fossa, including the cavernous sinus, the
parasellar region, the tentorium, and the dura of the
petrous apex.
• These branches also innervate the floor of the anterior
cranial fossa, including the falx and the major blood
vessels at the skull base.

divisions of CN V
• The lacrimal and frontal nerves enter orbital apex
outside annulus of Zinn. At its terminus, the frontal
nerve divides into supraorbital and supratrochlear
branches, which innervate the forehead, frontal
sinus, and upper eyelid (including the conjunctiva).
The lacrimal nerve also runs anteriorly in superior
lateral orbit just above the lateral rectus to
innervate lacrimal gland and some skin just
superotemporal to the orbit. The nasociliary branch
is the only branch entering the intraconal space
through the annulus of Zinn.

divisions of CN V
• The nasociliary branch runs through the ciliary
ganglion and anteriorly to innervate the globe
through the short and long posterior ciliary nerves.
Prior to reaching globe, branches from the
nasociliary division pass through the anterior and
posterior ethmoidal foramina to innervate part of
the ethmoidal sinuses, the lateral wall of the nose,
and the skin of the nose to the nasal tip. This co-
innervation of the globe and the nasal skin is the
reason behind the development of the Hutchinson
sign in patients with zoster ophthalmicus.

divisions of CN V
• The maxillary division (V2) runs forward at the inferior
lateral base of the cavernous sinus to enter the
foramen rotundum, located just below the superior
orbital fissure. Just before entering the canal, V2 gives
off the middle meningeal nerve, which supplies the
dura of the lateral middle cranial fossa. On the anterior
end of the foramen rotundum, V2 enters the
pterygomaxillary area. Two large pterygopalatine
nerves supply sensation to the nasopharynx, hard and
soft palate, and portions of the nasal cavity. Posterior
alveolar nerves supply sensation to the upper gums and
molars.

divisions of CN V
• The zygomatic nerve enters the orbit through the
inferior orbital fissure and divides into
zygomaticofacial and the zygomaticotemporal
nerves, which supply sensation to lateral face . The
maxillary nerve continues anteriorly within a canal
between the orbit above and the maxillary sinus
below to exit through the infraorbital foramen (as
the infraorbital nerve) just below the inferior orbital
rim. It subsequently divides into palpebral, nasal,
and labial branches. The sensation of the cheek as
well as the lower eyelid and upper teeth and gums
is provided by this division.

divisions of CN V
• mandibular division (V3) enters through foramen
ovale, lateral to foramen lacerum and medial to
the foramen spinosum (carrying the MMA). V3
innervates the skin of the jaw and carries the
motor division of the trigeminal nerve to the
muscles of mastication and neck. Motor paralysis
results in contralateral deviation of the jaw when it
is closed (weakness of the temporalis) and
ipsilateral deviation when protruded (because of
weakness in the lateral pterygoid).

Facial Nerve (CN VII)
• Figure 1-38 Supranuclear, nuclear, and infranuclear anatomy
of the facial nerve (CN VII).
• A, The corticobulbar fibers travel through the internal
capsule down into the medial one-third of the corticospinal
tracts in the cerebral peduncles of the midbrain. The
pathways for the upper third of facial function (brow and
orbicularis muscles) run parallel but apparently distinct
from pathways for the lower two-thirds along the pyramidal
tracts. The corticobulbar fibers travel in the basis pontis;
those that control the lower facial muscles decussate at the
level of the pons to synapse on the contralateral CN VII
nucleus. Corticobulbar fibers that control the upper facial
muscles decussate to synapse on the contralateral CN VII
nucleus, and some of the fibers do not cross, reaching the
ipsilateral CN VII nucleus

• B, CN VII is predominantly motor in function, with its
nucleus located in the caudal pons. CN VII courses
dorsomedially and encircles the nucleus of CN VI. After
bending around the CN VI nucleus, CN VII exits the pons in
the cerebellopontine angle close to CN V, CN VI, and CN
VIII. CN VIII, the motor root of CN VII, and the nervus
intermedius (the sensory and parasympathetic root of CN
VII) enter the internal auditory meatus. Sensory cells
located in the geniculate ganglion continue distally as the
chorda tympani nerve, which carries taste fibers. Peripheral
fibers of the nervus intermedius portion of CN VII initiate
salivary, lacrimal, and mucous secretion.
• C, After emerging from the parotid gland, CN VII innervates
the muscles of facial expression via 5 peripheral branches.

The facial nerve. A, B, and C denote lesions of the facial nerve at the stylomastoid
foramen, distal and proximal to the geniculate ganglion, respectively. Green lines
indicate the parasympathetic fibers, red line indicates motor fibers, and purple
lines indicate visceral afferent fibers (taste)

• Within the petrous bone, CN VII enters the fallopian
canal and traverses 3 segments (the labyrinthine, the
tympanic, and the mastoid) that run in close proximity
to the semicircular canals. The parasympathetic fibers
destined for the lacrimal gland separate from CN VII in
the region of the geniculate ganglion to accompany the
greater superficial petrosal nerve. The stapedial nerve
exits to innervate the stapedius muscle, and chorda
tympani conducts parasympathetic innervation to the
submaxillary gland and afferent fibers from the anterior
two-thirds of the tongue. These special afferent fibers
are responsible for taste in the anterior tongue and
synapse in the geniculate ganglion.

• The main branch of CN VII exits the stylomastoid
foramen just behind the styloid process at the base of
the mastoid. The extracranial trunk of the nerve
passes between the superficial and deep lobes of the
parotid gland, where it divides into 2 trunks: the
temporofacial superiorly and the smaller cervicofacial
inferiorly. These further variably divide into 5 major
branches: the temporal, zygomatic, infraorbital, buccal,
and mandibular. The temporal and zygomatic branches
laterally innervate the orbicularis oculi muscles. The
infraorbital and buccal branches may also contribute to
the inferior orbicularis.

Facial Nerve (7th Cranial Nerve)—Test for
• Raising the eyebrows.
• Ask the patient to gently close the eyelids as if they
are sleeping. The amount of lagophthalmos can be
measured with a millimeter rule .
• Forceful closure of eyes for orbicularis oculi,
• Blink reflex—Loss of spontaneous blink may occur
in patients with apparently normal voluntary lid
closure, and is a helpful clue to suggest prior seventh
nerve palsy.

Facial Nerve (7th Cranial
Nerve)—Test for
• Blowing the mouth, saying “eee”—look for deviation
of the mouth.
• Taste sensation of the anterior two-thirds of the
tongue.
• Tear function—Schirmer’s test.
• Bell’s phenomenon—it indicates how well the
cornea is protected when the patient is asleep.

Facial Nerve PALSY
• A complete interruption of the facial nerve at the
stylomastoid foramen paralyzes all muscles of facial
expression. The corner of the mouth droops, the
creases and skinfolds are effaced, the forehead is
unfurrowed, and the eyelids will not close. Upon
attempted closure of the lids, the eye on the paralyzed
side rolls upward (Bell's phenomenon). The lower lid
sags and falls away from the conjunctiva, permitting
tears to spill over the cheek. Food collects between the
teeth and lips, and saliva may dribble from the corner
of the mouth. The patient complains of a heaviness or
numbness in the face, but sensory loss is rarely
demonstrable and taste is intact.

Facial Nerve PALSY
• If the lesion is in the middle-ear portion, taste is
lost over the anterior two-thirds of the tongue on
the same side. If the nerve to the stapedius is
interrupted, there is hyperacusis (sensitivity to
loud sounds). Lesions in the internal auditory
meatus may affect the adjacent auditory and
vestibular nerves, causing deafness, tinnitus, or
dizziness. Intrapontine lesions that paralyze the
face usually affect the abducens nucleus as well,
and often the corticospinal and sensory tracts.

• If the peripheral facial paralysis has existed for
some time and recovery of motor function is
incomplete, a continuous diffuse contraction of
facial muscles may appear. The palpebral fissure
becomes narrowed, and the nasolabial fold
deepens. Attempts to move one group of facial
muscles may result in contraction of all
(associated movements, or synkinesis). Facial
spasms, initiated by movements of the face, may
develop (hemifacial spasm).

• Anomalous regeneration of seventh nerve fibers
may result in other troublesome phenomena. If
fibers originally connected with the orbicularis
oculi come to innervate the orbicularis oris, closure
of the lids may cause a retraction of the mouth, or
if fibers originally connected with muscles of the
face later innervate the lacrimal gland, anomalous
tearing ("crocodile tears") may occur with any
activity of the facial muscles, such as eating.
Another facial synkinesia is triggered by jaw
opening, causing closure of the eyelids on the side
of the facial palsy (jaw-winking).

BELL’S PALSY
• The most common form of facial paralysis is Bell’s palsy.
The annual incidence of this idiopathic disorder is ~25 per
100,000 annually, or about 1 in 60 persons in a lifetime. Risk
factors include pregnancy and diabetes mellitus.
• Clinical Manifestations The onset of Bell’s palsy is fairly
abrupt, with maximal weakness being attained by 48 h as a
general rule. Pain behind the ear may precede the paralysis
for a day or two. Taste sensation may be lost unilaterally,
and hyperacusis may be present.
• In some cases, there is mild cerebrospinal fluid
lymphocytosis. Magnetic resonance imaging (MRI) may
reveal swelling and uniform enhancement of the geniculate
ganglion and facial nerve and, in some cases, entrapment of
the swollen nerve in the temporal bone.

BELL’S PALSY
• Approximately 80% of patients recover within a few
weeks or months. Electromyography may be of
some prognostic value; evidence of denervation
after 10 days indicates there has been axonal
degeneration, that there will be a long delay (3
months as a rule) before regeneration occurs, and
that it may be incomplete. The presence of
incomplete paralysis in the first week is the most
favorable prognostic sign. Recurrences are
reported in approximately 7% of cases.

TREATMENT Bell’s Palsy
• Symptomatic measures include (1) the use of
paper tape to depress the upper eyelid
during sleep and prevent corneal drying, and
(2) massage of the weakened muscles.
• A course of glucocorticoids, given as
prednisone 60–80 mg daily during the first 5
days and then tapered over the next 5 days,
modestly shortens the recovery period and
improves the functional outcome.

TREATMENT Bell’s Palsy
• Although large and wellcontrolled randomized trials
found no added benefit of the antiviral agents
valacyclovir (1000 mg daily for 5–7 days) or
acyclovir (400 mg five times daily for 10 days)
compared to glucocorticoids alone, some earlier
data suggested that combination therapy with
prednisone plus valacyclovir might be marginally
better than prednisolone alone, especially in
patients with severe clinical presentations.

Ocular Autonomic Pathways
• Branches of parasympathetic system play a role in
lacrimal function, and pupil size is controlled by a
balance between innervation of sympathetic fibers
to iris dilator muscles and of parasympathetic
fibers to the sphincter muscles. The accessory
retractor muscles, including the Müller muscle in
the upper eyelid, receive sympathetic innervation.

Sympathetic Pathways
• Sympathetic activity originates in the posterolateral
region of the hypothalamus. Activity in the
hypothalamus is influenced by signals in the frontal,
sensorimotor, and occipital cortex and in the limbic
system (cingulate gyrus). The course of sympathetic
fibers destined for the orbit is divided into first-,
second-, and third-order segments . Axons destined for
the dilator muscles of the pupil and Müller muscle
descend as the first-order segment, along with other
sympathetic fibers, superficially in the anteromedial
column through the brainstem to the spinal cord. the
sympathetic fibers destined for the orbit synapse in the
ciliospinal center of Budge-Waller .

• The postsynaptic second-order fibers leave the spinal cord
through the ventral rami of the cervical (C8) and upper
thoracic (T1 and T2) levels before joining the paravertebral
sympathetic plexus. Ascending rostrally, the sympathetic
chain passes in the anterior loop of the ansa subclavia
proximate to the innominate artery on the right and the
subclavian artery on the left just above the lung apex.
These fibers pass through the inferior and middle cervical
ganglia to terminate in the superior cervical ganglion, at the
level of the angle of the jaw (C2) and the carotid artery
bifurcation.
• The postganglionic third-order fibers continue in the wall of
the bifurcated carotid. Sympathetic fibers innervating the
sweat glands of the lower face follow the ECA.

Anatomy of
the
sympathetic
pathway

• anteriorly in the cavernous sinus, the sympathetic fibers
join the nasociliary branch of V1. In the orbital apex, the
fibers then pass through the ciliary ganglion (without
synapsing). Along with the nasociliary branch, the
sympathetic fibers reach the globe and travel with the long
ciliary nerves to the dilator muscles of the pupil. The dilator
muscle lies just superficial to the posterior pigment
epithelium of the iris, which continues peripherally as the
nonpigmented superficial layer of the ciliary body. The
myoepithelial cells measure approximately 12.5 μm in
thickness, with an apical epithelial portion and a basilar
muscular portion that is oriented radially toward the
pupillary opening. The muscular processes terminate
peripheral to the sphincter muscle. Peripherally at the iris
root, these cells are continuous with the pigmented
epithelium of the ciliary body.

• The fibers destined for the Müller muscle travel
along the OphA and its subsequent frontal &
lacrimal branches. The Müller muscle originates
near the origin of the levator aponeurosis and
inserts 10–12 mm inferiorly on the superior border
of the tarsus. The superior orbital sympathetic
fibers also innervate the sweat glands of the
forehead. Thus, disruption of these sympathetic
fibers is responsible for the mild ptosis and the
frontal anhidrosis associated with distal Horner
syndrome.

Parasympathetic Pathways
• Parasympathetic activity originates in various areas within
brainstem. The fibers that control pupil sphincter muscles
originate in the Edinger-Westphal (EW) nuclei of CN III
nuclear complex within the midbrain. The main input to the
EW nuclei is from the pretectal nuclei, both directly and via
the posterior commissure. The pretectal nuclei, in turn,
receive input directly from the afferent visual pathways via
the pupillary tract, which leaves the optic tract in the
brachium of the superior colliculus just anterior to the LGN.
The cortex (especially the frontal lobes), the hypothalamus,
and the reticular activating system provide tonic inhibitory
signals to the EW nucleus.
• During sleep, the pupil becomes smaller through loss of this
inhibitory activity.

Pathway of the pupillary reaction
to light

Parasympathetic Pathways
• The parasympathetic fibers and the CN III fascicles
leave the CN III nucleus and exit in the interpeduncular
fossa. Within the subarachnoid space, the
parasympathetic fibers tend to run on the medial
superficial surface of CN III. When CN III bifurcates in
the anterior cavernous sinus, the parasympathetic
fibers travel with the inferior division. In the orbital
apex, these fibers synapse in the ciliary ganglion (as
opposed to the oculosympathetic and nasociliary
fibers, which travel through the ganglion without
synapse). The postsynaptic fibers then travel with the
branch destined for the inferior oblique muscle to join
the posterior ciliary nerves to reach anterior segment
and iris sphincter muscles.

Parasympathetic innervation to the lacrimal gland
• Parasympathetic innervation to the lacrimal gland
originates in the superior salivatory (salivary) nucleus
located in the caudal pons posterolateral to the motor
nucleus of CN VII. This nucleus receives sensory input from
the trigeminal nerve and additional afferent fibers from the
hypothalamus. Efferent parasympathetic fibers for lacrimal,
mucous, and salivary secretion leaving the nucleus join
other parasympathetic efferent fibers coming from the
salivatory nucleus and run with afferent gustatory fibers
from the anterior two-thirds of the tongue in the nervus
intermedius. The gustatory fibers synapse in the nucleus of
the tractus solitarius parallel to the fascicles of CN VII in
the nervus intermedius . This nerve joins with CN VII to exit
the brainstem on its ventral surface of the pontomedullary
junction.

SUPRANUCLEAR EYE
MOVEMENT SYSTEMS
• There are five supranuclear eye movement
systems. They are:
• 1. Saccadic system
• 2. Pursuit system
• 3. Vergence system
• 4. Non-optic reflex system
• 5. Position maintenance system.

HORNER SYNDROME
• A 55-year-old man with hypertension complains of
acute headache on the left and is found to have a
left Horner syndrome. How should he be worked up
and treated?
• This patient with an acute, isolated, painful Horner
syndrome is considered to have a left internal
carotid artery dissection until proven otherwise. He
must be evaluated emergently with noninvasive
cerebrovascular imaging studies. If a dissection is
confirmed, he will have to be admitted and treated
to prevent a cerebral infarction .

Treatment of Horner Syndrome
• Most patients with Horner syndrome have no visual
changes and tolerate a mild ptosis. Rarely, lid
surgery is requested to correct a persistent ptosis.
Topical apraclonidine corrects the ptosis
associated with Horner syndrome and may be used
intermittently for cosmetic reasons or when the
ptosis reduces the superior visual field.

Papilloedema
• Papilloedema is swelling of the optic nerve head
secondary to raised intracranial pressure (ICP).
‘Disc swelling’ and ‘disc oedema’ are non-specific
terms that include papilloedema but also a disc
swollen from other causes. All patients with
papilloedema should be suspected of harbouring an
intracranial mass. Not all patients with raised ICP
will develop disc swelling.

Cerebrospinal fluid Circulation
• Cerebrospinal fluid (CSF) is formed by the choroid
plexus in the ventricles of the brain.
• It leaves the lateral ventricles to enter the third
ventricle through the foramina of Munro.
• From the third ventricle, it flows through the
Sylvian aqueduct to the fourth ventricle.
• From the fourth ventricle, the CSF passes through
the foramina of Luschka and Magendie to enter the
subarachnoid space, flowing around the spinal cord
and bathing the cerebral hemispheres.

Cerebrospinal fluid Circulation
• Absorption is into the cerebral venous system through arachnoid villi.
• Normal CSF pressure on lumbar puncture is 10–18 cmH2O in adults.
• • Causes of raised ICP
• Idiopathic intracranial hypertension.
• Obstruction of the ventricular system by congenital or acquired lesions.
• Space-occupying intracranial lesions, including haemorrhage.
• Impairment of CSF absorption due to meningitis, subarachnoid
haemorrhage or trauma.
• Cerebral venous sinus thrombosis.
• Cerebral oedema from blunt head trauma.
• Severe systemic hypertension.

Diagnosis of raised ICP
• Headaches, which characteristically occur early in the
morning and may wake the patient from sleep, although
less commonly they can occur at any time of day. The
pain may be generalized or localized, and may intensify
with head movement, bending or coughing. They tend
to get progressively worse over time. Very rarely,
headache may be absent.
• Nausea, often episodic and with associated projectile
vomiting; may occur as an isolated feature or may
precede the onset of headaches.
• Deterioration of consciousness as severity increases,
initially with drowsiness and somnolence. A dramatic
deterioration in concscious level may be indicative of
brainstem distortion and requires immediate attention.

• Visual symptoms are commonly absent in mild or early
raised ICP.
• Transient visual obscurations lasting up to 30 seconds in
one or both eyes are frequent in established papilloedema,
and are sometimes precipitated by bending, coughing or the
Valsalva manoeuvre; disc swelling due to other causes is
usually associated with more persistent visual impairment.
• Horizontal diplopia due to sixth nerve palsy caused by
stretching of one or both abducens nerves over the petrous
tip ; this is a false localizing sign.
• Vision is generally normal or minimally reduced. Significant
reduction is a late feature in conjunction with secondary
optic atrophy.

• MRI to exclude a space-occupying lesion and/or
enlarged ventricles; MRI can also be used to
measure ONSD (average normal diameter
approximately 5.5 mm ± 1 mm on MRI).
• In certain cases vascular imaging may be
performed, such as venography to rule out cerebral
venous sinus thrombosis.
• Lumbar puncture (LP) must not be carried out until
imaging has excluded a space-occupying lesion
that might cause downwards herniation of the
intracranial

OPHTHALMOSCOPIC PICTURE
• It is useful to characterize the changes in the optic nerve head that occur in
papilledema as being mechanical or vascular in nature.
• The five mechanical clinical signs of optic disc
edema are:
• Blurring of the optic disc margins.
• Filling in of the optic disc cup.
• Anterior extension of the nerve head (3 D = 1 mm
of elevation).
• Edema of the nerve fiber layer.
• Retinal or choroidal folds, or both.

The five vascular clinical signs of
optic disc edema
• Venous congestion of arcuate and peripapillary
vessels.
• Papillary and retinal peripapillary hemorrhages.
• Nerve fiber layer infarcts (cotton-wool spots).
• Hyperemia of the optic nerve head.
• Hard exudates of the optic disc.

Stages of papilloedema
• Papilloedema is nearly always bilateral, but may be
asymmetrical.
• • Early Mild disc hyperaemia with preservation of the
optic cup.
• Indistinct peripapillary retinal nerve striations and disc
margins.
• SVP is absent in about 20% of normal individuals and
may be difficult to identify even when present. An
identifiable venous pulsation in at least one eye means
that the ICP is normal at that point in time, bearing in
mind that diurnal fluctuation can occur.

• Established (acute –)
• Normal or reduced VA.
• Severe disc hyperaemia, moderate elevation with indistinct margins and
absence of the physiological cup.
• Venous engorgement, peripapillary flame haemorrhages and frequently
cotton wool spots.
• As the swelling increases, the optic nerve head appears enlarged.
• Circumferential retinal folds (Paton lines) may develop, especially
temporally .
• Macular fan: in younger patients small vesicles may form in the
superficial retina, converging on the fovea in a fan shape with the apex
at the fovea; this is not to be confused with a macular star, composed of
exudates.
• Enlarged blind spot.

• Chronic
• VA is variable and the visual fields begin to constrict.
• Disc elevation; cotton wool spots and haemorrhages
are characteristically no longer present.
• Optociliary shunts and drusen-like crystalline
deposits (corpora amylacea) may be present on the
disc surface.
• • Atrophic (secondary optic atrophy )
• VA is severely impaired.
• The optic discs are grey–white, slightly elevated, with
few crossing blood vessels and indistinct margins.

Papilloedema Treatment
• Weight loss, including via bariatric surgery, can be
very effective and formal dietary intervention is
strongly recommended.
• Other options include acetazolamide, furosemide,
digoxin and analgesia, and in unresponsive cases
optic nerve fenestration, lumboperitoneal shunting
and transverse dural sinus stenting.
• Steroids are controversial, but a short course is
sometimes used in severe papilloedema.
• Intravenous mannitol or a lumbar puncture are
usually reserved for acute severe exacerbations.

idiopathic
intracranial hypertension (IIH)
• modified Dandy criteria should be met for the
diagnosis of pseudotumor cerebri or IIH . The
patient should first demonstrate the signs and
symptoms of increased intracranial pressure.
Headache, transient visual obscurations, pulse-
synchronous tinnitus, papilledema with associated
visual loss, and diplopia due to sixth nerve palsies
are the common presenting symptoms and signs.

Idiopathic intracranial hypertension
• there should be an absence of localized findings on
neurological examination except for the “false
localizing” sixth nerve palsies. Neuroimaging should
reveal the absence of deformity, displacement, or
obstruction of the ventricular system. We like to use
magnetic resonance imaging (MRI) and magnetic
resonance venography (MRV) to look for additional
support for the presence of intracranial hypertension.
Findings characteristic of increased intracranial
pressure on MRI are empty sella, smooth-walled venous
stenoses of the lateral sinuses (on MRV), orbital
findings related to the unfolding of the nerve sheath,
and enhancement of the optic disc.

Idiopathic intracranial
hypertension MANAGEMENT
• I generally treat all patients with a low-sodium weight
management program. Patients usually improve with
weight loss of 5% to 10% body weight. Much more
weight loss is usually not sustainable and does not
appear to be necessary for IIH remission. Weight loss
may be all our patient needs, since there is no visual
loss with perimetric examination except for enlarged
blind spots. However, if her symptoms of intracranial
hypertension (eg, severe headache) were interfering
with her activities of daily living, I would start
acetazolamide in 2 divided doses, then gradually
escalating doses to 1 to 2 g per day.
• Diuretics can be used if the patient cannot tolerate
acetazolamide.

Idiopathic intracranial
hypertension MANAGEMENT
• The frequency of follow-up depends mostly on the risk
of visual loss. The 2 most important factors here are
amount of visual loss present and the degree of optic
disc edema. If the risk of further visual loss is low; the
usual revisit time after diagnosis is 1 to 2 months. I
would have this patient back in 2 months and, if she is
doing well, again in 4 months. Since IIH can be a
lifelong disease (like arterial hypertension), I follow
patients who are in remission every 1 to 2 years. The
• key features in following a patient are the change in
weight, change in symptoms, perimetry results, and
papilledema grade .

Summary
• IIH is a diagnosis of exclusion (modified Dandy
criteria).
• The typical patient with IIH is an overweight young
female; more aggressive evaluation for possible
etiologies should be considered in thin patients, men,
and the elderly.
• Medical treatment with weight loss and acetazolamide
are the first lines of therapy.
• Surgical treatment (optic nerve sheath fenestration or
shunting procedures) is reserved for patients with
progressive disease who fail maximal medical therapy.

MYASTHENIA GRAVIS
• A 68-year-old woman presents with complaints of
droopy upper lids over the past few weeks.
• Sometimes one lid or the other might even close
completely. She has also noticed double vision, which
comes and goes.
• Since the majority of patients with myasthenia gravis
present with involvement of the lids and extraocular
muscles, the ophthalmologist is often the first
physician to make this diagnosis, usually based on key
history and clinical findings in the office. These reveal
a typically variable clinical picture that is modulated by
rest and fatigue; they also help establish localization
distal to the brainstem and cranial nerves.

MYASTHENIA GRAVIS
• key questions that address typical characteristics of
myasthenia—namely improvement with rest,
fatigability, and variability.
• The one question that I find most useful, and that
addresses the effect of rest, is whether the ptosis or
diplopia is present upon first awakening. Most patients
with myasthenic ptosis report that the lids are virtually
normal or much improved first thing after sleep.
Similarly, a report by a patient with diplopia of little or
no double vision upon awakening strongly suggests
myasthenia and reflects improvement from a tropia to a
phoria during sleep. This is in contrast to other causes
of diplopia where overnight ocular dissociation leads to
a tropia upon awakening with improvement afterward.

Key Physical Findings
• Pupils
• The pupils are not clinically affected by myasthenia gravis.
There should be no pupillary dilation or Horner syndrome.
• Ptosis
• There are several lid findings suggestive of myasthenia
gravis. Bilateral ptosis is common in myasthenia but rare in
brainstem or cranial nerve disorders. However, the bilateral
nature of the ptosis may be masked by the effect of
Hering’s law, in which the effort to open the more ptotic lid
brings the less ptotic lid into a normal or even a retracted
position. In apparently unilateral ptosis, lift the ptotic lid
and observe whether the “normal” (or retracted) lid
becomes ptotic .

Key Physical Findings
• Motility
• The presence of bilateral limitation of eye movement is very
helpful since in myasthenia both eyes are commonly involved ,
whereas bilateral involvement would be most unlikely in
brainstem or cranial nerve lesions. A motility pattern appearing
to be an isolated unilateral cranial neuropathy or internuclear
ophthalmoplegia may occur in myasthenia. However, it is
uncommon for myasthenia gravis to mimic these patterns without
other findings, such as ptosis or orbicularis weakness.
• Orbicularis
• You should test orbicularis function in all patients with ptosis or
motility problems. The orbicularis is weak in most myasthenic
patients , often visibly fatiguing with continued testing. The
presence of orbicularis weakness in a patient with ptosis and
motility abnormalities indicates a localization that cannot be
explained by a brainstem or cranial nerve lesion.

Management
• If additional symptoms suggest generalized
myasthenia gravis or if the isolated ocular
symptoms are of recent onset, you should
refer to a neuromuscular specialist in a
timely manner. I warn the patient that if
problems with breathing or swallowing
develop in the meantime, an urgent visit to
an emergency department would be in order.

MANAGEMENT
• I usually defer to neuromuscular specialist to begin
a trial of pyridostigmine, then I see the patient
again after a few weeks. If patient has isolated
ocular myasthenia gravis and pyridostigmine has
not been fully effective, I add prednisone since this
is usually more effective for the ocular signs and
may decrease the rate of generalization. I usually
start at 1 mg/kg per day for 2 weeks, followed by
tapering. This results in remission for some
patients, but others need a maintenance alternate-
day dose.

Summary
• Clues that make myasthenia a consideration in a
patient with ptosis, diplopia, or both include the
following:
• Effect of rest
• Symptoms absent upon awakening
• Ptosis improves after office rest/ice test
• Fatigable ptosis
• Variable symptoms and findings
• Bilateral findings not mapping to cranial nerves
• Orbicularis weakness

THANK
YOU
DR DINESH
DR SONALEE

Neuro ophthalmology 2016

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