Neuro-ophthalmology Flashcards
To review high yield N-O topics and concepts.
1
Q
(start 72) When an imaging study fails to demonstrate the expected pathology in relation to the clinical presentation, the clinician’s first step is to..
A
reexamine the study parameters, ideally with a neuroradiologist.
2
Q
Best quantifies torsional strabismus
A
double Maddox rod - when vertical diplopia is present
3
Q
Diagnostic of neurosyphilis
A
positive CSF VDRL
4
Q
Patient presents with intraocular inflammation and positive RPR. Next step?
A
lumbar puncture with CSF examination, followed by antibiotic therapy (series of IV or IM dosing)
5
Q
Consists of paired subnuclei for the superior rectus, inferior rectus, medial rectus, and inferior oblique muscles as well as paired subnuclei for the pupillary constrictor muscles and single subnucleus for the levator palpebrae
A
CN III nuclear complex
6
Q
Subnuclei for the superior rectus supply..
A
the contralateral superior rectus muscle
7
Q
Actions of the superior oblique muscle
A
intorts, depresses, abducts the eye
8
Q
Presentation of bilateral CN IV palsy
A
crossed hypertropia (right hyper on left gaze and left hyper on right gaze) extorsion of at least 10 degrees, large V-pattern esotropia greater than 25 PD (esotropia greatest on downgaze), and chin-down positioning (as hypertropia decreases in upgaze)
9
Q
Cerebral achromatopsia is a feature of this type of lesion
A
occipital lobe
10
Q
Pursuit and reflexive saccade movements are initiated in this region
A
parietal lobe, abnormal OKN responses can be seen related to a parietal lobe lesion
11
Q
Abnormal OKN response. Where is the lesion?
A
Parietal lobe
12
Q
VF defects commonly present with disc drusen
A
enlarged blind spot and ARCUATE SCOTOMAs
13
Q
2 ways B-scan can differeniate calcified drusen from papilledema
A
1) highly reflective, calcified drusen maintain high echogenicity with lowering of U/S gain
2) with papilledema, intraorbital portion of ON is widened and will decrease in width with prolonged lateral gaze (30 degree test”); ODD do not produce widening of the intraorbital nerve.
14
Q
Anatomic location of most ODD
A
anterior to lamina cribosa and posterior to Bruch membrane (lamina choroidalis portion of the intraocular optic nerve)
15
Q
When does aberrant regeneration occur?
A
after trauma or compression by an aneurysm or tumor but does not occur with microvascular ischemia
16
Q
What is primary aberrant regeneration?
A
aberrant regeneration without a h/o CN III palsy - evidence of a slowly expanding parasellar lesion - m/c meningioma or carotid aneurysm within the cavernous sinus.
17
Q
Eyelid retraction in downgaze, eyelid elevation or pupil constriction on attempted adduction, and globe retraction on attempted upgaze
A
aberrant regeneration
18
Q
Branch of the posterior cerebral artery that supplies the primary visual cortex
A
calcarine branch
19
Q
Supply most of the blood supply to the skull and its contents. Be specific
A
Common carotid arteries arising from the innominate artery on the right and directly from the aorta on the left
20
Q
Systemic evaluation for patient with suspected oculopharyngeal muscular dystrophy
A
genetic testing - PABPN1 - encodes for polyadenylate binding protein nuclear 1, only associated gene.
21
Q
Diagnosis of OPMD (oculopharyngeal muscular dystrophy) relies on this molecular diagnosis
A
expansion of a GCN trinucleotide in the first exon of PABPN1 (commercially available test)
22
Q
postpartum or recent SSRI + recurrent HA + hemianopic field loss with MRA showing “string of beads” appearance of cerebral arteries.
A
Reversible cerebral vasoconstriction syndrome (RCVS)
23
Q
Prognosis of RCVS (reversible cerebral vasoconstriction syndrome)
A
resolves within 3 months
24
Q
T1 MRI with contrast of brain with enhancing lesion of tectum of midbrain would confirm the diagnosis
A
Dorsal midbrain syndrome (Parinaud) syndrome
25
Signs of dorsal midbrain syndrome
1) convergence-retraction nystagmus (co-contraction of EOMs wtih attempted upgaze)
2) Conjugate limitation of vertical gaze (upgaze deficit)
3) skew deviation
4) eyelid retraction in primary position (Collier sign)
5) convergence abnormalities (convergence spasm or convergence palsy)
6) mid-dilated pupils, poorly reactive pupils with light-near dissociation
26
Most likely cause of diplopia in parinaud/pretectal syndrome
Skew deviation
27
Cause for optic disc edema with exudate in macula start pattern
M/c Bartonella henselae, less common syphilis, toxoplasmosis, lyme disease, tuberculosis, viruses. May also be postviral autoimmune process
28
Most common cause of divergence insufficiency (DI) in an otherwise healthy adult patient?`
Connective tissue involution between the superior and lateral rectus muscles causing inferior displacement of the lateral rectus muscles (sagging eye syndrome)
29
What is divergence insufficiency?`
acquired ocular misalignment defined by an esodeviation that is greater at distance than near fixation without lateral incomitance, and without abduction deficits.
30
Website for BCSC Self-assessment
https://bcscap.aao.org/Dashboard
31
Characteristic optic nerve appearance in dominant optic atrophy
Temporal pallor with an area of triangular excavation (wedge-shaped pallor)
32
Characteristic optic nerve appearance in Leber hereditary optic neuropathy (LHON)
Peripapillary telangiectasia
33
Characteristic optic nerve appearance in glaucoma
Superotemporal or inferotemporal notching
34
Characteristic optic nerve appearance in optic nerve hypoplasia
Yellow peripapillary halo with ring of pigmentation
35
What test would best distinguish a retinopathy from an optic neuropathy?
Photostress recovery
36
Characterized by short severe attacks of pain with cranial autonomic features (ptosis, miosis)
Paroxysmal hemicrania
37
Bouts of unilateral excruciating headaches with autonomic features lasting 15-180 minutes
Cluster headaches
38
Continuous unilateral headache
Hemicrania continua
39
Episodic very brief sharp stabbing stabbing pains/HA with no autonomic features
Idiopathic stabbing headache
40
Specific steps of cocaine test
Instill 2 drops of cocaine 4% or 10% in each eye 5 minutes apart
Measure anisocoria 45 minutes to 1 hour
Postcocaine anisocoria >1mm is diagnostic of Horner syndrome on the side of the smaller pupil
41
Mechanism of cocaine
Blocks reuptake of norepinephrine released at sympathetic nerve terminals in the eye causing pupillary dilation, eyelid retraction, conjunctival blanching
42
Portion of a CN that travels within brainstem
Fasicle
43
What structures lie adjacent to the fascicles of CN III?
Substantia nigra + red nucleus -(Benedikt syndrome)
superior cerebellar peduncle - (Nothnagel) (superior cerebellar peduncle + red nucleus = Claude syndrome)
cerebral peduncle - (Weber syndrome)
corticospinal tracts
44
Nothnagel syndrome
CN III + superior cerebellar peduncle
45
Benedikt syndrome lesion
CNIII + red nucleus + substantia nigra
46
Weber syndrome
CNIII + cerebral peduncle
47
Claude syndrome
CNIII + superior cerebellar peduncle + red nucleus
48
CN IV courses below the
Pineal gland
49
Where does the CN VI nucleus lie?
Below the 4th ventricle and it’s fasicles pass medial to the superior olivary nucleus
50
Passes medial to the superior olivary nucleus
Fasicles of CN VI
51
M/c hereditary optic neuropathy
Dominant optic atrophy
52
M/c mutation in DOA
OPA1 gene on chromosome 3
53
Optic neuropathy with cardiac conduction defects
Leber hereditary optic neuropathy pre-excitation syndrome
54
Eye movement dysfunction in congenital ocular motor apraxia
Horizontal saccades
Increased latency and intermittent failure of initiation
55
Nerve that courses along surface of clivus
Abducens nerve
Underneath the petroclinoid (gruber) ligament to enter the dorello canal
56
Structure in brainstem responsible for excitatory burst in horizontal movement
Paramedian Pontine Reticular Formation
Located adjacent to the CN VII nucleus
57
Neural integrator for horizontal movement
Nucleus prepositus hypoglossi (NPH)
58
Excitatory burst cells and neural integrator for vertical/torsional movement
Rostral interstitial nucleus of the medial longitudinal fasiculus
(riMFL)
Interstitial nucleus of Cajal (INC)
59
CN IV palsy with lesion at predescussation fasicular or nuclear level
Ipsilateral RAPD without vision or color loss (decussation of nasal pupillary fibers)
Contralateral Horner’s 2/2 proximity of sympathetic fibers
60
Assessment that may best distinguish between a retinopathy and optic neuropathy.
Electrophysiology
Electroretinogram (ERG) and visual evoked potentials (VEP) can be very specific in localizing etiology to retina or optic nerve
61
Electrophysiology consistent with a retinopathy compared to an optic neuropathy
Abnormal ERG and VEP would be seen in a retinopathy whereas a normal ERG and abnormal VEP is highly suggestive of an optic neuropathy.
62
Within the cavernous sinus, what cranial nerve do the sympathetic fibers run with?
CN VI
Sympathetic fibers destined for the dilator muscles leave the carotid in conjunction with CN VI for a few millimeters. Further anteriorly in the cavernous sinus, the sympathetic fibers join the nasociliary branch of CN V1. The sympathetic fibers do not join any of the other cranial nerves within the cavernous sinus.
63
When does optic neuropathy occur after radiation therapy?
on average 18 months and produces subacute optic neuropathy
64
Where are saccadic eye movements generated?
Frontal eye fields located in the frontal lobe, one on each side. Each frontal eye field initiates saccades to the contralateral side.
65
Where are smooth pursuit eye movements generated?
Medial temporal (MT) visual area (V5) in the parietal lobe. Each generates smooth pursuit eye movements to the ipsilateral side.
66
Name for inability to initiate saccades
ocular motor apraxia - results from injury to the frontal lobe or may occur in childhood conditions
67
Condition visual evoked potential (VEP) testing is most helpful in confirming
Demyelinating optic neuropathy. Measures electrical signals over the occipital cortex produced in response to verbal stimulus. Shows increased latency in demyelination
68
Formed hallucinations + insomnia + excessive daytime somnolence. Where is the lesion?
MIDBRAIN - constant hallucinations frequently associated with inverted sleep-wake cycle (peduncular hallucinosis)
69
Pallinopsia
illusion of persistent afterimages that can be a/w visual hallucinations
70
Region of brain that produces olfactory and gustatory hallucinations, with complex formed hallucinations in the ipsilateral or contralateral field
temporal lobe
71
Lesion to this region of brain commonly cause unformed hallucinations, geometric colors or patterns
Occipital lobe
72
Slowly progressing facial palsies strongly suggest this. Preferred imaging test?
MRI brain. Brainstem mass.
73
Frequent origin of facial myokymia with continuous or undulating contraction of facial muscles
intramedullary pons. In children - pontine glioma and adults multiple sclerosis
74
Condition that commonly leads to congenital Horner syndrome
Brachial plexus injury (birth trauma)
75
irregular myocytes "ragged-red" fibers and inclusion body abnormalities on EM from a muscle biopsy
Mitochondrial myopathy
76
Myotonic discharges seen on electromyography
Myotonic dystrophy
77
Infant develops conjugate horizontal nystagmus with null point. OK drum testing shows reversal of normally expected OK nystagmus.
Bilateral pregeniculate visual loss - Sensory nystagmus arises when central VA is too poor to develop central fixation
78
Infantile disease that does not produce oscillopsia
Infantile nystagmus syndrome (INS) or congenital nystagmus
79
Evaluation for sensory nystagmus (pregeniculate visual loss)
optic neuropathy, foveal hypoplasia, retinal dystrophy
80
Two characteristics of infantile nystagmus (INS)
1. Reversal of normal pattern of optokinetic nystagmus (OKN). Patients with INS respond to OKN drum rotation with slow-phase eye movements in the direction opposite to that of rotating OKN drum
2. Velocity of slow-phase movement increases exponentially with distance from fixation. Increasing velocity waveform is punctuated by foveation periods.
81
Percentage of children with typical INS with no detectable afferent pathway abnormality
40%
82
If the pupil affected by Horner syndrome fails to dilate with hydroxyamphetamine, where is the defect
Postganglionic neuron - hydroxyamphetamine acts to release NE from the presynaptic terminal. In normal eye or in preganglionic horner syndrome, the postganglionic neuron is intact with normal dilation of pupil.
83
Large vessel vasculitides
GCA, Takayasu arteritis
84
Medium-size vessel vasculitis
Polyarteritis nodosa and Kawasaki disease
85
Small vessel vasculitis
Granulomatosis with polyangiitis
86
Abnormality most frequently associated with ONH drusen
Peripheral visual field constriction
87
Ocular findings in neurofibromatosis 1 (NF1)
Lisch nodules, prominent corneal nerves, choroidal hamartomas
88
What are lisch nodules
hamartomas (tissue normally found at site but in increased amount) flat or dome-shaped iris nodules usually less than 1 mm and tan to dark brown in color. Composed of schwann cells, fibroblast like cells, mast cells
89
What disease are lisch nodules seen and how frequently?
NF1 - 10% of children by age 1, 100% by age 10. Presence of 2 or more is criteria for diagnosing NF1
90
Diagnosis of NF1 criteria
```
6 or more café-au-lait
2 or more neurofibromas
intertriginous freckling
ON glioma
Lisch nodules (2+)
Distinctive osseous lesion
first degree relative with NF1
```
91
Genetics of NF1
NF1 gene on chromosome 17 q11.20, product is neurofibromin, a tumor suppressant. Loss of neurofibromin leads to cell and tumor growth
92
Myopathic facies, frontal balding, ptosis, myopathy affecting distal muscles first. Low intelligence, insult resistance, hearing loss, cardiomyopathy, cardiac conduction abnormalities, testicular/uterine atrophy. Diagnosis and ocular findings?
Myotonic dystrophy (dominant, chromosome 19) with pigmentary retinopathy, polychromatic lenticular deposits ("Christmas tree" cataracts), sluggish miotic pupils.
93
Should be performed in every case of typical optic neuritis?
MRI brain to assess long-term risk for developing MS over the next 15 years (25% if no lesions, 72% with = 1 lesion)
94
Most important exam finding to help determine risk of corneal ulceration in patient with stroke and facial nerve palsy?
Corneal sensation - determine if trigeminal neuropathy present that may eliminate corneal sensitivity - combo of anesthetic cornea and lagophthalmos places these patients at high risk for developing corneal exposure and ulceration.
95
Vesicles along posterior aspect of external auditory canal, over tympanic membrane or over pinna
Ramsay Hunt syndrome - Herpes zoster involving the seventh cranial nerve
96
Acquired cases of prosopagnosia result from stroke of which portion of brain
bilateral inferior occipitotemporal lobes or right inferior occipital lobe
97
Inability to recognize familiar faces
prosopagnosia - disorder of recognition involving visual-visual disconnection
98
Part of brain responsible for processing physical attributes of an object
Ventral occipitotemporal pathway
99
Part of brain responsible for visuospatial processing and gulidance of movement towards an object
Dorsal occipitoparietal pathway
100
Patient cannot read but can write. What is this called and what part of brain is damaged?
Alexia without agraphia - damage to splenium of the corpus callosum and the left occipital lobe
101
Damage to the midbrain and cerebral peduncle
contralateral hemiparesis (Weber syndrome)
102
Damage to red nucleus and substantia nigra
contralateral ataxia or tremor (Benedikt syndrome)
103
Damage to dorsal midbrain
May involvesuperior cerebellar peduncle and produce contralateral ataxia (Claude syndrome)
104
Dorsal brainstem lesion with CN III nuclear lesion may produce supranuclear eye movement dysfunction. Also known as
Nothnagel syndrome
105
Inferior notch would lead to this defect
Dense superior arcuate defect
106
Part of optic nerve most sensitive to trauma or sinus surgery
Intracanalicular optic nerve
107
What could compress the intracranial optic nerve
Sellar masses or internal carotid aneurysms
108
May cause any ocular motility deficit
Myasthenia gravis
109
In a patient with an acute optic neuropathy, what symptom suggests the arteritic form?
Prior transient monocular visual loss
110
Sudden painful vision loss of right eye followed by similar sx 2 weeks later in her left eye. MRI shows bilateral enhancement of ON. After treatment with methylprednisolone, only minimal visual recovery. Diagnosis?
Neuromyelitis optica
111
SE of fingolimod
macular edema
112
For patients with MS, what disease-modifying therapy has most often been a/w progressive alteration of mental status resulting from a homonymous hemianopia?
Natalizumab in patients with Jacob-Crotzfeld-virus positive - progressive multifocal leukoencephalopathy
113
Confirms diagnosis of horner syndrome
cocaine drops (hydroxyamphetamine can localize the lesion producing horners to preganglionic or postganglionic)
114
infant with acquired horner's syndrome
neuroblastoma - originates in either adrenal gland or sympathetic ganglion chain in the retroperitoneum or mediastinum which interrupts papillary sympathetic innervation
115
Most frequent source of childhood orbital metastasis
neuroblastoma
116
strabismus, hemorrhage, hyphema, ocular or periocular inflammation, glaucoma, proptosis, hypopyon
Rb (m/c leukocoria) but know other presentations
117
Supranuclear ocular motor system responsible for maintaining an image on the fovea during brief head movements
vestibular-ocular system
118
Triad of simultanagnosia, optic ataxia, and ocular motor apraxia
Balint syndrome (bilateral occipitoparietal lesions)
119
"Where pathway"
dorsal occipitoparietal pathway - visuospatial analysis, localization of objects, visually directed movements toward objects
120
"What pathway"
ventral occipitotemporal pathway - color, shape, pattern recognition
121
Lesion causes object agnosia
lesion to bilateral ventral occipitotemporal pathway ("what pathway")
122
episodic diplopia lasting 30-60 seconds after sustained activation of cranial ocular motor nerve
Ocular neuromytonia - a/w h/o radiation therapy for skull-based neoplasm
123
Neuroimaging finding characteristic of tuberous sclerosis
intracranial calcified hamartoma
124
Cerebellar hemangioblastoma
von Hippel-Lindau
125
Leptomeningeal vascular malformation
Sturge-Weber syndrome (encephalofacial angiomatosis)
126
Next step if more than 1 CN involved
Neurological evaluation with neuroimaging, which if normal, LP with cytopathologic examination should be considered.
127
CN palsy most commonly a/w IIH
CN VI (unilateral or bilateral)
128
Facial nerve palsy combined with hearing loss and vestibular dysfunction
Cerebellopontine (CPA) angle mass
129
M/c CN involved in sarcoidosis
CN VII (parotid gland)
130
Recurrent unilateral or bilateral facial paralysis + chronic facial swelling and lingua plicata (furrowing of tongue)
Melkersson-Rosenthal syndrome
131
"salt and pepper" retinopathy + ptosis and ophthalmoplegia
Kearns-Sayre syndrome (variant of chronic progressive external ophthalmoplegia, AD) Cardiac conduction defects may be fatal if untreated
132
Patient with intraocular inflammation and testing reveals positive RPR test. Next step
Lumbar puncture with CSF exam f/b antibiotic therapy
133
What does the CN III nuclear complex contain
paired subnuclei for 4 extraocular muscles the superior rectus, interior rectus, medial rectus, inferior oblique, paired subnuclei for the pupillary constrictor (Edinger-Westphal) and single subnucleus for the levator palpebrae muscles (central caudal nucleus)
134
Clinical sign expected in bilateral fourth CN palsies
V-pattern esotropia (esotropia greatest on downgaze), chin-down positioning (as hypertropia decreases in upgaze)
135
How could one differentiate a parietal lobe lesion from an occipital lobe lesion?
Parietal lobe initiates pursuit and reflexive saccade movements - abnormal OKN responses. Occipital lobe lesion will have intact OKN response - results in cerebral achromatopsia
136
How would examiner elicit impaired OKN response
moving targets toward the lesion, inducing attempts to use the damaged pursuit pathway
137
Homonymous hemianopia with reduced OKN response with target moving toward the affected side
Parietal lobe lesion
138
Complication following 3rd CN palsy suggestive of nonischemic cause?
Aberrant regeneration - most commonly produces eyelid retraction in downgaze, eyelid elevation or pupil constriction on attempted adduction, and globe retraction on attempted upgaze.
139
Branch of the posterior cerebral artery that supplies the primary visual cortex
Calcarine branch
140
Systemic evaluation should be performed on a patient with suspected oculopharyngeal muscular dystrophy
Genetic testing for PABPN1 which encodes for polyadenylate binding protein nuclear 1
141
Severe recurrent headaches with or without focal neurologic deficits and/or seizures with segmental constriction of cerebral arteries that resolves within 3 months occurring after postpartum period or exposure to vasoactive substances (SSRIs)
Reversible cerebral vasoconstriction syndrome (RCVS)
142
Middle-aged woman postpartum with light sensitivity, blurred vision, hemianopic visual field loss and "string-of-beads" on MRA
Reversible cerebral vasoconstriction syndrome (RCVS)
143
Dorsal midbrain syndrome features. What is the cause of diplopia?
```
Convergence-retraction nystagmus
Upgaze deficit
Skew deviation (diplopia)
Eyelid retraction
Convergence abnormalities
Poorly reactive pupils with light-near dissociation
```
144
Most common cause of divergence insufficiency in healthy adult
Connective tissue involution between the superior and lateral rectus muscles.
145
What is divergence insufficiency (DI)
An acquired ocular misalignment defined by an esodeviation that is greater at distance than near fixation without lateral incomitance and without abduction deficits.
146
Good exam technique for monocular vision loss.
Vertical prism dissociation test. A 4 prism diopter lens is placed base-down in front of the eye with better vision. If they can read the upper and lower images of a vertical prism dissociated 20/20 line, it can prove normal visual acuity.
147
Exam findings with aberrant regeneration of CN III?
Eyelid retraction with adduction or pupillary miosis with supraduction, adduction or infraduction
148
Workup for NSOI
Crohn disease, SLE, RA, DM, MG, ankylosing spondylitis (Cytoplasmic staining pattern (c-ANCA), ANA, ACE, lysozyme, IgG4
149
NSOI occurs in these patterns
5 patterns: M/c are extraocular muscles (myositis), lacrimal gland (dacryoadenitis), anterior orbit (scleritis), orbital apex, or diffuse inflammation throughout orbit.
150
Optic nerve finding most characteristic of dominant optic atrophy?
Wedge-shaped optic nerve pallor.
151
ON exam with yellow peripapillary halo with ring of pigmentation
Optic nerve hypoplasia
152
ON exam with peripapillary telangiectasia
Leber hereditary optic neuropathy (LHON)
153
Test to best distinguish a retinopathy from an optic neuropathy
Photostress recovery
154
Several episodes per day of severe left-sided orbital and temporal pain that lasts 5-10 minutes, occasionally a/w left ptosis and miosis..
Paroxysmal hemicrania - form of trigeminal autonomic cephalgia a/w short bouts of pain highly responsive to indomethacin
155
Difference between cluster headache and paroxysmal hemicrania
both may have autonomic features but cluster headache have longer duration (15-180 minutes)
156
Hemicrania continua
continuous unilateral headaches
157
Why does an internal carotid dissection produce pain and horner syndrome?
involvement of sympathetic fibers in the wall of the carotid artery
158
Earliest pathologic change to occur in KCN?
Bowman layer - focal discontinuities
159
Ocular motility abnormality classically included in dorsal midbrain syndrome?
Convergence-retraction nystagmus
160
Retraction of the eyelids in primary position
Collier sign
161
What structures lie adjacent to the fascicles of CN III?
Substantia nigra
CN III passes adjacent to the superior cerebellar penduncle, cerebral peduncle, red nucleus, substantia nigra, corticospinal tracts.
162
Brainstem structure that generates horizontal saccades
Paramedian pontine reticular formation
163
What supranuclear structure if damaged can be a/w diplopia and strabismus
thalamus
164
Continuous unilateral undulating contraction of the orbicularis oculi and most of the facial muscles
Facial myokymia - Pontine glioma or demyelination (MS) signifies intramedullary disease of the pons involving CN VII nucleus or fasicle
165
Trigeminal neuralgia can result from what artery coming in contact with the trigeminal root in the subarachnoid space?
Superior cerebellar artery
166
Left CN III nucleus lesion
bilateral ptosis, left adduction and depression deficit, right elevation deficit.
167
Horners with anhidrosis limited to the ipsilateral forehead
lesion at or distal to the superior cervical ganglion (third order Horner syndrome)
168
Interruption of central (first order) or preganglionic (second order) neuron causes
anhidrosis of the ipsilateral head, face, neck. May produce Harlequin syndrome, one-half of face is pale and other half normal or reddish (white is lesion denervated sympathetics supersensitivity to circulating adrenaline)
169
Term for illusion of object that moves in elliptical path rather than straight line
Pulflrich phenomenon
170
Ability to see moving, but not static objects in a blind hemifield (statokinetic dissociation)
Riddoch phenomenon
171
Preservation of a visual image after removal of original stimulus
Palinopsia - may be illusory (triggered by contrast and/or motion) or hallucinatory (a/w homonymous VF loss and caused by cortical lesions)
172
Inability to perform visually guided movements
Optic ataxia
173
Difference between myelinated retinal nerve fiber layer at ON margin versus optic disc drusen
retinal vessel obscuration
174
Nystagmus worse in down and lateral gaze to either side. What structure is most likely to have a lesion
Flocculus of the cerebellum
175
Cause of downbeat nystagmus
vestibulocerebellum (nodulus, uvula, floccus, parafloccus of the cerebellum)
176
Cause of upbeat nystagmus
medulla
177
Cause of parinaud syndrome
dorsal midbrain
178
Cause of seesaw nystagmus (where is the lesion)
parasellar region/diencephalon
179
Transient monocular vision loss a/w eye pain that improves when patient lies down
Ocular ischemic syndrome
180
Findings on DFE in ocular ischemic syndrome
midperipheral dot-blot hemorrhages and dilated veins due to low central arterial pressure. +/- episcleral injection and aqueous flare due to ischemic uveitis
