Fluorescein Angiography Findings in Susac Syndrome: A Multicenter Retrospective Case Series.

BACKGROUND: Susac syndrome is a vasculopathy, resulting in the classic triad of branch retinal artery occlusion (BRAO), inner ear ischemia, and brain ischemia. In this retrospective chart review, we characterize fluorescein angiography (FA) findings and other ancillary studies in Susac syndrome, including the appearance of persistent disease activity and the occurrence of new subclinical disease on FA. METHODS: This multicenter, retrospective case series was institutional review board-approved and included patients with the complete triad of Susac syndrome evaluated with FA, contrasted MRI of the brain, and audiometry from 2010 to 2020. The medical records were reviewed for these ancillary tests, along with demographics, symptoms, visual acuity, visual field defects, and findings on fundoscopy. Clinical relapse was defined as any objective evidence of disease activity during the follow-up period after initial induction of clinical quiescence. The main outcome measure was the sensitivity of ancillary testing, including FA, MRI, and audiometry, to detect relapse. RESULTS: Twenty of the 31 (64%) patients had the complete triad of brain, retinal, and vestibulocochlear involvement from Susac syndrome and were included. Median age at diagnosis was 43.5 years (range 21-63), and 14 (70%) were women. Hearing loss occurred in 20 (100%), encephalopathy in 13 (65%), vertigo in 15 (75%), and headaches in 19 (95%) throughout the course of follow-up. Median visual acuity at both onset and final visit was 20/20 in both eyes. Seventeen (85%) had BRAO at baseline, and 10 (50%) experienced subsequent BRAO during follow-up. FA revealed nonspecific leakage from previous arteriolar damage in 20 (100%), including in patients who were otherwise in remission. Of the 11 episodes of disease activity in which all testing modalities were performed, visual field testing/fundoscopy was abnormal in 4 (36.4%), MRI brain in 2 (18.2%), audiogram in 8 (72.7%), and FA in 9 (81.8%). CONCLUSIONS: New leakage on FA is the most sensitive marker of active disease. Persistent leakage represents previous damage, whereas new areas of leakage suggest ongoing disease activity that requires consideration of modifying immunosuppressive therapy.

Asymmetric Inferior Predilection of Lisch Nodules With Unilateral Ptosis.

Lisch nodules are melanocytic hamartomas that have been hypothesized to grow larger in the presence of sunlight. A 17-year-old boy with neurofibromatosis Type 1 and congenital ptosis in one eye presented and was found to have a distinct asymmetry of Lisch nodules between eyes with less under the ptotic lid. This case supports the theory that Lisch nodules form at least partially due to a direct trophic effect of sunlight.

Prevalence of Retinal Emboli and Acute Retinal Artery Occlusion in Acute Ischemic Stroke.

OBJECTIVE: In population-based studies asymptomatic retinal emboli occur in .32%-2.9% of people. Retinal artery occlusion (RAO) may occur concurrently with cerebral stroke but the frequency is unknown. No study has examined how commonly retinal emboli occur in the acute stroke population. We aimed to assess the prevalence of retinal emboli and RAO at the time of carotid territory ischemic stroke. METHODS: Patients were enrolled prospectively after onset of symptoms consistent with the diagnosis of carotid territory ischemic stroke. Every participant underwent pharmacologic dilation of both pupils and bedside funduscopic examination. Emboli were classified as cholesterol, calcific, platelet/fibrin, or other and categorized by the side of occurrence. Stroke was classified as atheroembolic, cardioembolic, embolic stroke of undetermined source, lacunar, or other. Acute RAO was diagnosed by direct visualization of ischemic retinal whitening. RESULTS: Sixty-five patients were enrolled with a mean age of 59.2 years; 23 were female (35.4%). Eleven of 65 subjects (16.9%) had retinal emboli visible on funduscopy; all were cholesterol emboli except a single platelet/fibrin embolus in a patient with atheroembolic source. Six patients (9%) had acute RAO and no RAO was seen in the lacunar or undetermined source subgroups. CONCLUSIONS: Retinal emboli occurred more than 10 times more frequently in the acute stroke patient than in large population-based studies. RAOs also occurred concurrently with ischemic stroke. Although emboli were seen in patients with atheroembolic and cardioembolic sources, all patients with carotid disease had emboli in the ipsilateral eye. Future studies are required to determine if the presence of retinal emboli or RAO may help elucidate an etiology in patients suffering from embolic stroke of undetermined source.

Diagnostic Criteria and Treatment Algorithm for Susac Syndrome.

BACKGROUND: Susac syndrome (SS) classically presents with the clinical triad of retinal artery occlusion, sensorineural hearing loss, and encephalopathy and the neuroimaging triad of white matter lesions, deep gray matter lesions, and leptomeningeal disease. However, patients can present with an incomplete clinical or neuroimaging triads making diagnosis difficult in certain situations. A standard treatment paradigm also is lacking in this illness. It is important for neuro-ophthalmologists to recognize clinical and radiographic findings that are pathognomonic for this syndrome and have a basic understanding of the available treatment options. EVIDENCE ACQUISITION: Review of medical literature. RESULTS: A definite diagnosis of SS is made when the clinical triad or the neuroimaging triad is present. There are numerous reports of 2 other imaging findings in this condition: arteriolar wall hyperfluorescence (AWH) on fluorescein angiography in retinal arterioles remote from retinal ischemia and central callosal lesions on MRI. Both of these imaging findings are diagnostic of SS. Gass plaques in retinal arterioles are almost always seen in the acute phase of the illness but are not pathognomonic for SS. The most common medications used in this syndrome are corticosteroids and intravenous immunoglobulin. A number of other medications have been used including mycopheolate, rituximab, azathioprine, and cyclophosphamide. CONCLUSIONS: In the absence of the clinical triad or magnetic resonance imaging triad for SS, AWH remote from retinal vascular injury and central callosal lesions are confirmatory of the diagnosis because they have never been described in any other condition. The presence of Gass plaques in retinal arterioles should strongly suggest the diagnosis. Despite the lack of clinical trial data, patients with SS must be treated promptly and aggressively. In more fulminant cases, addition of mycophenolate mofetil or rituximab is required, followed by cyclophosphamide when disease is refractory to other medications.

Retinal Arterio-Arterial Collaterals in Susac Syndrome.

BACKGROUND: The ophthalmic findings of Susac syndrome (SS) consist of visual field defects related to branch retinal artery occlusion (BRAO), and fluorescein angiography (FA) reveals a unique staining pattern. To date, retinal arterial collateral development has been described only in a single patient. Given that the immunopathological process in SS induces retinal ischemia, it is conceivable that abnormal blood vessel development may occur in affected individuals. METHODS: This is a retrospective observational study. The medical records including fundus photography and FA of all patients with SS were reviewed, and those with any type of retinal arterial collateral were identified. RESULTS: A total of 11 patients were identified with retinal collaterals. Five were men. Age ranged from 20 to 50 years. Ten patients had arterio-arterial (A-A) collaterals and 1 had arterio-venous (A-V) collaterals, and all had collaterals remote from the optic disc. No collaterals were present at onset of illness and the first developed at 9 months. CONCLUSIONS: The literature reveals scant evidence for the association between BRAO and retinal arterial collaterals. Our findings indicate that retinal arterial collaterals in SS are usually A-A and not A-V and may be more common in this disorder than previously believed. Collaterals do not develop early in the disease, and there may be a predilection toward development in men. The chronic inflammatory state of SS may be the stimulus for the development of these arterial collaterals.

Functional Vision Disorder.

Functional vision disorder (FVD) is a common problem seen in many neurologic and ophthalmologic practitioners' offices and may occur in isolation or in the presence of medical illness. This disorder presents with visual or oculomotor symptoms and manifests as vision loss in one or both eyes, visual field loss, double vision, oscillopsia, anisocoria, blepharospasm, or ptosis. Manual perimetry is the most effective method for determining functional visual loss, and the presence of a central scotoma in a functional visual field signifies that a neuropathophysiologic process is almost certainly present. The exact neuropathophysiologic mechanism of this disorder is unknown; however, information can be drawn from the small studies of FVD samples and studies examining neuropsychiatric factors in other conversion disorder semiologies. Psychological and psychiatric interventions can be useful in treating these patients.

Appearance and resolution of numerous bilateral gass plaques in probable Susac syndrome.

Purpose: To describe a patient with a unique retinal phenotype of probable Susac syndrome. Observations: A 47-year-old female who presented with bilateral tinnitus and vision changes was found to have bilateral sensorineural hearing loss and many bilateral retinal arteriolar Gass plaques. She had bilateral scotomas corresponding with temporal thinning and atrophy of the inner nuclear layer (INL) on OCT. Retinal examination and fluorescein angiography demonstrated minimal arteriolar wall hyperfluorescence with no evidence of acute branch retinal artery occlusion. She developed daily headaches. MRI of the brain was normal with no corpus callosal lesions. She was diagnosed with probable Susac syndrome based on the above findings. Conclusions and importance: Our patient's bilateral high frequency sensorineural hearing loss, numerous bilateral Gass plaques, and headaches are most likely attributable to Susac syndrome. While BRAO is considered a cornerstone of retinal involvement in Susac syndrome, it may only be appreciable angiographically in the acute setting, and it is important to recognize Gass plaques as a significant diagnostic marker of disease.

Splenium of the Corpus Callosum Infarct Associated With COVID-19: Case Report.

INTRODUCTION: Coronavirus disease 2019 (COVID-19) has been recently associated with infarction of the central splenium of the corpus callosum. These are described as cytotoxic lesions, and imaging rarely reveals enhancement. They have not been described in the body or head of the corpus callosum. Few diseases affect the corpus callosum, but the most common include multiple sclerosis, aquaporin-4 disease, and Susac syndrome. There is also emerging literature on Mild Encephalopathy with Reversible Splenial lesions associated with central and not basal lesions. The reason for the location of these lesions in acute COVID-19 infection is unknown. CASE REPORT: A 22-year-old female presented to the ED for altered mental status after being found down. A brief history review indicated that the patient had been altered for 2-3 days before being found naked and covered in her own feces and urine by her family after they had not heard from her. As she lived alone, a clear history of the events preceding her admission remains unclear. On initial assessment, the patient was found to be somnolent and nonverbal, though she could follow simple commands. On admission, testing for SARS CoV-2 RNA PCR was positive. Patient was admitted to the hospital for further work up to determine the cause of the altered mental status. CONCLUSION: We present a new case of a young woman who developed a central splenium lesion during acute COVID-19 infection and explain the predilection for the callosum in these patients, as well as literature to show that COVID-19 was most likely the cause.

Posterior Cortical Atrophy: Characteristics From a Clinical Data Registry.

Background: Posterior cortical atrophy (PCA) is a neurodegenerative syndrome that presents with higher-order visual dysfunction with relative sparing of memory and other cognitive domains, and it is most commonly associated with Alzheimer's disease pathology. There is a lack of data regarding the presentation of PCA to non-cognitive specialists. Therefore, we collected clinical data from neuro-ophthalmologists regarding the presentation of PCA to their practices and compared data to published cohorts and a published survey of cognitive specialists. Methods: Members of the North American Neuro-Ophthalmology Society Listserv (NANOSnet) were invited to complete an online, retrospective, chart-review data-entry survey regarding their patients with PCA, and REDCap was used for data collection. Results: Data for 38 patients were entered by 12 neuro-ophthalmologists. Patient mean age at presentation was 67.8 years, and 74% of patients were women. Difficulty reading was reported at presentation by 91% of patients, and poor performance on color vision, stereopsis, and visual field testing (performed reliably by 36/38 patients) were common findings. Most patients who were treated were treated with donepezil and/or memantine. Conclusions: Compared to published data from cognitive specialists, patients presenting to neuro-ophthalmology with PCA were more likely to be older and female and have a reading complaint. Reliable visual field testing was the norm with homonymous defects in the majority of patients. The neuro-ophthalmologist plays an important role in diagnosing PCA in older adults with unexplained visual signs and symptoms, and future studies of PCA should involve multiple specialists in order to advance our understanding of PCA and develop effective treatments.

Susac's syndrome: 1975-2005 microangiopathy/autoimmune endotheliopathy.

Susac's syndrome (SS) consists of the clinical triad of encephalopathy, branch retinal artery occlusions (BRAO) and hearing loss. It is due to a microangiopathy affecting the precapillary arterioles of the brain, retina, and inner ear (cochlea and semicircular canals). Women are more commonly affected than men (3:1); the age of onset ranges from 9 to 58 years; but young women between the ages of 20 and 40 are most vulnerable. The encephalopathy is almost always accompanied by headache which may be the presenting feature. Multifocal neurological signs and symptoms, psychiatric disturbances, cognitive changes, memory loss, and confusion may rapidly progress to dementia. The MRI shows a distinctive white matter disturbance that always affects the corpus callosum. The central callosal fibers are particularly vulnerable and central callosal holes develop as the active lesions resolve. Linear defects (spokes) and rather large round lesions (snowballs) sometime dominate the MRI findings, which include cortical, deep gray (70%) and leptomeningeal involvement (33%). Frequently, the lesions enhance and may be evident on diffusion weighted imaging (DWI). The BRAO are best evaluated with fluorescein angiography, which may show the pathognomonic multifocal fluorescence. Gass plaques are frequently present and reflect endothelial damage. Brain biopsy shows microinfarction to be the basic pathology, but more recent pathological studies have shown endothelial changes that are typical for an antiendothelial cell injury syndrome. Elevated levels of Factor VIII and von Willebrand Factor Antigen reflect the endothelial perturbation. Despite extensive evaluations, a procoagulant state has never been demonstrated. SS is an autoimmune endotheliopathy that requires treatment with immunosuppressants: steroids, cyclophosphamide, and intravenous immunoglobulin, usually in combination. Aspirin is a useful adjunct.

Intermittent reversal of complete ptosis associated with sphenoid wing meningiomas.

CASE REPORT: Ptosis secondary to dense oculomotor pareses generally improves over several months, but intermittent elevation of the eyelid has not been reported. The authors describe two patients who demonstrated intermittent involuntary monocular eyelid elevation in an eye with complete ptosis caused by partial resection of sphenoid wing meningioma. Both patients had complete ophthalmoplegia and decreased corneal sensation. The involved eye was ipsilateral to a meningioma that had been debulked 11 to 12 months previously. Although the lids were devoid of volitional movement, each patient could elevate the lid for 10 to 20 seconds by either tickling the eyelashes or rubbing the eyelids. The lids occasionally rose spontaneously and there was no clinical evidence of aberrant regeneration or cyclic spasm. COMMENTS: Although the mechanism of action of this involuntary eyelid elevation is unknown, it is possible that some process of aberrant regeneration activated by sensory stimuli is responsible.

Idiopathic repetitive oculomotor nerve palsies in otherwise normal patients.

OBJECTIVE: To describe a unique idiopathic disorder characterized by transient repetitive unilateral oculomotor pareses. DESIGN: Retrospective observational case series. PARTICIPANTS: Three women presenting for tertiary neuro-ophthalmologic evaluation. METHODS: Review of patient records. MAIN OUTCOME MEASURES: Historical information, clinical examination, neuroimaging, and laboratory evaluation for myasthenia gravis. RESULTS: Three 44- to 69-year-old women had recurrent unilateral ptosis over the course of 2 to 4 years. Two had concurrent diplopia with ipsilateral limitation of adduction, and 2 also had a large poorly reactive pupil in the involved eye during the episodes. The attacks lasted between 30 seconds and 4 hours and occurred up to 6 times daily. None of the patients were migraineurs, nor had they received radiation therapy. Neuro-ophthalmologically normal between episodes, all patients had normal magnetic resonance imaging/angiography and testing for myasthenia gravis. CONCLUSION: Transient, recurrent, unilateral oculomotor nerve palsies may occur spontaneously in healthy individuals. The pathogenesis remains obscure, but the multiple recurrences without evident sequelae and the failure to develop any systemic or neurological disorder suggest that this phenomenon is not indicative of a serious underlying disorder.

Treatment of corticosteroid dependent optic neuropathy with intravenous immunoglobulin.

PURPOSE: To report a patient with corticosteroid dependent optic neuropathy treated with intravenous immunoglobulin (IVIg). DESIGN: Interventional case report. METHODS: Records review. RESULTS: A 25-year-old woman developed bilateral vision loss with pain on eye movement in association with disk edema, dilated retinal veins, and hemorrhage. The vision improved markedly with prednisone, but she required a minimum of 20 mg/d despite concomitant therapy with methotrexate, cyclosporine, and/or mycophenolate mofetil. IVIg, 0.5 g/kg/d for 3 days each month with subsequent reduction in frequency, allowed discontinuation of all immunosuppression. CONCLUSIONS: Corticosteroid dependent optic neuropathy was successfully treated with IVIg.

Neuro-ophthalmologic and electroretinographic findings in pantothenate kinase-associated neurodegeneration (formerly Hallervorden-Spatz syndrome).

PURPOSE: The onset of pantothenate kinase-associated neurodegeneration (PKAN) occurs in the first and second decade of life and a pigmentary retinal degeneration is a feature of the disorder. Since the neuro-ophthalmologic and electroretinographic (ERG) features have never been well delineated, we describe them in 16 patients with PKAN. DESIGN: Observational case series. METHODS: Sixteen patients with genetic and neuroimaging-confirmed PKAN were examined. Ten underwent neuro-ophthalmologic examination and all had ERGs. RESULTS: Of the 10 who underwent neuro-ophthalmologic examination, all showed saccadic pursuits and eight showed hypometric or slowed vertical saccades. Seven of eight had inability to suppress the vestibulo-ocular reflex; two patients could not cooperate. Two had square wave jerks and four had poor convergence. Vertical optokinetic responses were abnormal in five, and two patients had blepharospasm. Eight patients had sectoral iris paralysis and partial loss of the pupillary ruff consistent with Adie's pupils in both eyes. Only four of 10 examined patients showed a pigmentary retinopathy, but 11 of 16 had abnormal ERGs ranging from mild cone abnormalities to severe rod-cone dysfunction. No patient had optic atrophy. The PANK2 mutations of all of the patients were heterogeneous. CONCLUSIONS: Adie's-like pupils, abnormal vertical saccades, and saccadic pursuits were very common. These findings suggest that mid-brain degeneration occurs in PKAN more frequently than previously thought. ERG abnormalities were present in approximately 70% and no patient had optic atrophy. Although genotype-ocular phenotype correlations could not be established, allelic differences probably contributed to the variable clinical expression of retinopathy and other clinical characteristics in these patients.

Clinical and electrophysiologic characterization of paraneoplastic and autoimmune retinopathies associated with antienolase antibodies.

PURPOSE: Paraneoplastic and autoimmune retinopathies are immunologically mediated retinal degenerations that are associated with antibodies directed against any of several retinal proteins, including alpha-enolase. We report the clinical and electrophysiological features of antienolase retinopathy in contrast to the features of antirecoverin retinopathy. DESIGN: Retrospective, observational case series. METHODS: Patients were referred for evaluation of unexplained acquired visual symptoms, including photopsias, and loss of visual acuity or field considered of possible retinal origin. Full-field and multifocal electroretinograms (ERGs) were performed. Sera from patients were examined for antiretinal antibodies by Western blot analysis using proteins extracted from human retinas and by immunohistochemistry; antienolase was confirmed by incubating patient sera with purified alpha-enolase. RESULTS: Of 87 patients with unexplained retinal visual symptoms associated with abnormal ERGs, 37 (43%) demonstrated autoantibodies to retinal antigens, including 12 against alpha-enolase, of whom 4 had cancer. Initial visual loss was typically central and often asymmetric. The ERGs demonstrated mostly normal rod responses but central cone abnormalities (evident on multifocal ERG) and, for many, global cone abnormalities. Seven patients developed optic disk pallor. Corticosteroid and immunosuppressive therapy, when attempted, was clinically ineffective. CONCLUSIONS: Antienolase retinopathy is a protean autoimmune retinopathy that characteristically presents with cone dysfunction. The visual impairment and course vary from relative stability for years to slow progression with loss of central vision. With time, optic disk pallor can evolve, presumably from attrition of ganglion cells.