Common visual symptoms and findings in MS: Clues and Identification

Common visual symptoms and findings in MS: Clues and Identification Teresa C Frohman, PA-C, MSCS Neuro-ophthalmology Research Manager, UT Southwestern Medical Center at Dallas Professor Biomedical Engineering, University of Texas Dallas COMMON COMPLAINTS 1

Blurry Vision Corrected with Refraction? YES NO Refractive Error Keep Looking IN MS : ON, Diplopia, Nystagmus Most Common Visual Issues Encountered in MS patients Optic Neuritis Diplopia Nystagmus result from damage to the optic nerve or from an incoordination in the eye muscles or damage to a part of the oculomotor pathway or apparatus 2

Optic Neuritis Workup frosted glass Part of visual field missing Pain +/- Color desaturation Yes Work up for diplopia or nystagmus YES NO Seeing double images Or jiggling No Neuro-ophth exam Humphrey s OCT MRI Fundoscopy CRANIAL NERVE ANATOMY There are 12 pairs of cranial nerves CN I Smell CN II Vision CN III, IV, VI Oculomotor CN V Trigeminal Sensorimotor muscles of the Jaw CN VII Sensorimotor of the face CN VIII Hearing//vestibular CN IX, X, XII Mouth, esophagus, oropharynx CN XI Cervical Spine and shoulder 6 3

NEURO-OPHTHALMOLOGY EXAM Visual Acuity Color Vision Afferent pupillary reaction- objective test of CNII function Alternating flashlight test afferent arc of pupillary light reflex pathway Fundus exam Visual Fields confrontation at bedside CRANIAL NERVE II: OPTIC once the retinal ganglion cell axons leave the back of the eye they become myelinated behind the lamina cribosa ---and become the OPTIC NERVE Optic nerves pass through the optic canals and converge at the optic chiasm They continue to the thalamus where they synapse From there, the optic radiation fibers run to the visual cortex Functions solely by carrying afferent impulses for vision 4

CRANIAL NERVE II- OPTIC NERVE Assessment Cranial nerve II Visual Acuity snellen chart Visual Fields confrontation Fundoscopy Pupillary light reflex Snellen Chart Patient s own glasses/contacts Pinhole Pinhole refraction is a rapid, efficient way to diagnose refractive errors, which are the most common cause of blurred vision. However, with pinhole refraction, best correction is usually to only about 20/30, not 20/20. 9 CRANIAL NERVE II- OPTIC NERVE Assessment Cranial nerve II Visual Acuity Snellen chart Visual Fields Fundoscopy Pupillary light reflex Test by confrontation Assess superior, temporal, inferior and nasal fields Humphrey s Automated Perimetry Damage to an optic nerve results in blindness in the eye serviced by that nerve Damage to visual pathways distal to the optic chiasm results in partial visual losses. Visual defects are called anopsias. 10 5

VISUAL FIELD DEFECTS Visual fields 1 2 3 1. 3. 2. 4 5 Location of lesion: 1. Optic nerve ipsilateral (same side) blind eye 2. Chiasmatic (pituitary tumors classically) lateral half of both eyes gone 3. Optic tract opposite half of visual field gone 4. & 5. Distal to geniculate ganglion of thalamus: homonymous superior field (4) or homonymous inferior field (5) defect 11 CRANIAL NERVE II- OPTIC NERVE Assessment Cranial nerve II Visual Acuity snellen chart Visual Fields Fundoscopy Neuro-retinal rim-axons of RGC Orange pink w/central cup Axons die--white=pallor Pupillary light reflex Normal Optic disc pallor 12 6

CRANIAL NERVE II- OPTIC NERVE Assessment Cranial nerve II Visual Acuity snellen chart Visual Fields Fundoscopy Pupillary light reflex PUPILLARY LIGHT REFLEX Direct light reflex Consensual light reflex Swinging flashlight test APD, afferent pupillary defect 13 LEFT RELATIVE AFFERENT PUPILLARY DEFECT Normal Left Optic Neuritis/Neuropathy 7

OPTIC NEURITIS WORKUP Typically vision returns within a few weeks to months Many affect color vision even if acuity returns to 20/20 Can cause a large blind spot in center of visual field OCT will show thinner RNFL- OCT on the Cirrus OCT evaluating peripapillary RNFL thickness shows decreased average thickness, with thinning predominantly of the temporal aspects of both optic nerve heads. MRI -fat suppressed T1 weighted post gadolinium images. Optic Neuritis Workup frosted glass Part of visual field missing Pain +/- Color desaturation Yes Work up for diplopia or nystagmus YES NO Seeing double images Or jiggling No Humphrey s OCT MRI Fundoscopy 8

QUESTION TO START WITH Is it Unilateral or Bilateral Diplopia- caused by two images No double vision with monocular viewing = lens or cornea problem DIPLOPIA Diplopia (double vision), the experience of seeing two of everything, is caused by weakening or incoordination of eye muscles or supranuclear leasion (skew deviation) Common causes of Diplopia in MS INO 6 th Nerve Palsy > 3 rd nerve palsy > 4 th nerve palsy Skew deviation 9

EYE MOVEMENTS Controlled by CN III, IV, & VI CN III superior rectus inferior rectus medial rectus inferior oblique CN IV superior oblique CN VI lateral rectus Superior = in crowd = intorters Inferior = out crowd = extorters DIPLOPIA Common causes of Diplopia in MS INO 6 th > 3 rd > 4 th Nerve Palsy Skew deviation Internuclear Ophthalmoplegia INO adduction slowing with or without limitaton Most common oculomotor abn in MS Lesion of MLF ipsilateral Can cause diplopia when making saccades away from side of lesion 10

CN III, OCULOMOTOR Innervates SR, IR, MR, IO Elevates eyelid, levator palpebrae Constricts pupil via sphincter muscles of iris Contraction of ciliary muscle reduces tension on lens allowing focusing on closer objects A common treatment for this is to place an eye patch on the stronger (dominant) eye in order to strengthen the weaker muscles of the affected eye. CRANIAL NERVE IV: TROCHLEAR Fibers emerge from the dorsal midbrain and enter the orbits via the superior orbital fissures; innervate the superior oblique muscle Primarily a motor nerve that directs the eyeball Fourth Nerve Palsy Double vision following trochlear nerve palsy is most prominent when the patient adducts their eye, such as when walking downstairs or reading a book. Patients may also hold their head in a tilited position to compensate. 11

CRANIAL NERVE VI: ABDUCENS Sixth Nerve Palsy Sixth nerve palsy results in a patient unable to abduct the eye. It is also a false localizing sign in raised intracranial pressure or basal skull fracture. The long course of the abducens nerve leaves it vulnerable to pressure changes. In abducens nerve paralysis, the eye cannot. be moved laterally; at rest, the affected eyeball turns medially (internal strabismus), giving a person a 'cross-eyed' condition. IS IT HORIZONTAL OR VERTICAL 12

4 TH NERVE VS SKEW DEVIATION 4 TH NERVE PALSY 1. Hypertropia in primary position 2. Incomitant: hypertropia worse on gaze to opposite side acutely; may become comitant with time 3. Hypertropia worse on ipsilateral head tilt 4. Compensatory head tilt contralateral to the hypertropic eye 5. Excyclotorsion of the hypertropic eye 6. Usually no other neurologic signs (unless caused by brain trauma or lesions in brainstem) SKEW DEVIATION 1. Hypertropia in primary position 2. Incomitant, comitant, or alternating 3. Hypertropia may or may not change with head tilt 4. Pathologic head tilt contralateral to the hypertropic eye 5. Incyclotorsion of the hypertropic eye if present (and excyclotorsion of the hypotropic eye) 6. Usually has other neurologic signs (eg, gaze-evoked nystagmus, gaze palsy, dysarthria, ataxia, hemiplegia) Optic Neuritis Workup frosted glass Part of visual field missing Pain +/- Color desaturation YES NO Seeing double images Or jiggling Yes No Work up for diplopia or nystagmus Humphrey s OCT MRI Fundoscopy 13

NYSTAGMUS Nystagmus: Upon examination, the physician may detect a rhythmic jerkiness or bounce in one or both eyes. This relatively common visual finding in MS is nystagmus. Nystagmus does not always cause symptoms of which the person is aware. Mononcular Occluded fundoscopy Sometimes nystagmus can accompany INO, but it can also be due to any type of MS attack in the vestibular or inner ear part of the brainstem, or to the cerebellum, which is our coordination center. Final Thoughts In summary, vision can be impaired by MS in many different ways. People with MS who experience visual problems may benefit from an evaluation by both a neurologist and an ophthalmologist, or a neuro-ophthalmologist if one is available. Uhthoff s Phenomenon- esp: ON and INO 14

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