[Effects of Susac syndrome on the central vascular structure of the retina-An optical coherence tomography angiography study]. / Auswirkungen des Susac-Syndroms auf die zentrale Gefäßstruktur der Netzhaut ­ eine optische Kohärenztomographie-Angiographie-Studie.

BACKGROUND: Susac syndrome (SS) describes an endotheliopathy of vessels in the central nervous system. Retinal involvement plays a central role in the manifestation of the disease. OBJECTIVE: This case-control study investigated the macular microvasculature in patients with chronic SS compared to controls using optical coherence tomography angiography (OCTA). MATERIAL AND METHODS: 12 eyes of 12 patients with SS were compared with age-matched healthy control subjects with regard to their OCT angiographic parameters. The flow density (FD) of different macular layers, foveal avascular zone (FAZ) parameters and central retinal thickness and volume values were compared between the two groups. RESULTS: The FD of the choriocapillaris was reduced in Susac patients compared to healthy controls. The FD values of the superficial and deep capillary plexus of the inner retina, parameters of the FAZ as well as central retinal thickness and volume showed no significant differences between the two groups. DISCUSSION: Treated chronic SS does not appear to significantly affect the vascular and structural composition of the central inner retina; however, differences in the choriocapillaris indicate changes in deeper, highly vascularized capillary layers.

Central intra-lesional iron deposits as a possible novel imaging marker at 7 Tesla MRI in Susac Syndrome - an exploratory study.

BACKGROUND: Susac syndrome (SuS) is a rare autoimmune disease that leads to hearing impairment, visual field deficits, and encephalopathy due to an occlusion of precapillary arterioles in the brain, retina, and inner ear. Given the potentially disastrous outcome and difficulties in distinguishing SuS from its differential diagnoses, such as multiple sclerosis (MS), our exploratory study aimed at identifying potential new SuS-specific neuroimaging markers. METHODS: Seven patients with a definite diagnosis of SuS underwent magnetic resonance imaging (MRI) at 7 Tesla (7T), including T2* weighted and quantitative susceptibility mapping (QSM) sequences. T2 weighted hyperintense lesions were analyzed with regard to number, volume, localization, central vein sign, T1 hypointensity, and focal iron deposits in the center of SuS lesions ("iron dots"). Seven T MRI datasets from the same institute, comprising 75 patients with, among others, MS, served as controls. RESULTS: The "iron dot" sign was present in 71.4% (5/7) of the SuS patients, compared to 0% in our control cohort. Thus, sensitivity was 71.4% and specificity 100%. A central vein sign was only incidentally detected. CONCLUSION: We are the first to demonstrate this type of "iron dot" lesions on highly resolving 7T T2*w and QSM images in vivo as a promising neuroimaging marker of SuS, corroborating previous histopathological ex vivo findings.

Therapeutic plasma exchange in refractory Susac's syndrome: A brief report.

Susac's syndrome (SuS) is an autoimmune endotheliopathy that typically presents with the clinical triad of encephalopathy, hearing loss, and branch retinal artery occlusion. It has a wide range of possible presentations, and its pathogenesis remains uncertain. Fulminant and refractory cases are difficult to treat, and no standard treatment protocol has been established. However, therapeutic plasma exchange (TPE) has been described as an adjunctive therapy in several SuS cases. Herein we present a case of a 63-year-old male with debilitating encephalopathy and recent hearing and vision loss, who responded favorably to TPE. Given this and other published reports of plasma exchange therapy for SuS, treatment protocols should consider TPE in early stages of disease.

Use of disease assessment tools to increase the value of case reports on Susac syndrome: two case reports.

BACKGROUND: Susac syndrome is an immune-mediated, ischemia-producing, occlusive microvascular endotheliopathy that threatens the brain, retina, and inner ear. There is a need for disease assessment tools that can help clinicians and patients to more easily, accurately, and uniformly track the clinical course and outcome of Susac syndrome. Ideally, such tools should simultaneously facilitate the clinical care and study of Susac syndrome and improve the value of future case reports. To meet this need, two novel clinical assessment tools were developed: the Susac Symptoms Form and the Susac Disease Damage Score. The former is a comprehensive self-report form that is completed by patients/families to serially document the clinical status of a patient. The latter documents the extent of damage perceived by individual patients/families and their physicians. Both forms were initially trialed with two particularly representative and instructive patients. The results of this trial are shared in this report. CASE PRESENTATION: Patient 1 is a 21-year-old Caucasian female who presented with an acute onset of headache, paresthesias, cognitive dysfunction, and emotional lability. Patient 2 is a 14-year-old Caucasian female who presented with an acute onset of headache, cognitive dysfunction, urinary incontinence, ataxia, and personality change. Both patients fulfilled criteria for a definite diagnosis of Susac syndrome: both eventually developed brain, retinal, and inner ear involvement, and both had typical "snowball lesions" on magnetic resonance imaging. The Susac Symptoms Form documented initial improvement in both patients, was sufficiently sensitive in detecting a subsequent relapse in the second patient, and succinctly documented the long-term clinical course in both patients. The Disease Damage Score documented minimal disease damage in the first patient and more significant damage in the second. CONCLUSIONS: The Susac Symptoms Form and the Disease Damage Score are useful disease assessment tools, both for clinical care and research purposes. Their use could enhance the value of future case reports on Susac syndrome and could improve opportunities to learn from a series of such reports.

Susac syndrome - the current review of knowledge and own experience presentation.

Susac syndrome is a rare autoimmune vasculopathy involving the small precapillary arterioles of the brain, retina, and inner ear. It is characterized by a triad of symptoms: encephalopathy, visual disturbances due to obstruction of retinal artery branches, and sensorineural hearing loss. The study aimed to review the current medical knowledge on Susac syndrome and present our clinical experience regarding this disease entity. The paper also presents a case of a 25-year-old patient who was diagnosed with Susac's syndrome based on the clinical picture and the results of additional tests. This syndrome should be considered in the differential diagnosis of multiple sclerosis and other multifocal lesions of the central nervous system because early diagnosis of the disease and immunosuppressive treatment significantly alleviates its course and improves the prognosis.

Brain magnetic resonance imaging lesion load at diagnosis, severity at onset and outcomes in Susac syndrome: A prospective cohort study.

BACKGROUND: Susac syndrome (SuS) is a rare occlusive microvessel disease of the brain, retina and inner ear. We aimed to determine whether brain lesion load at the acute phase predicts poor outcomes in SuS. METHODS: A prospective national cohort study was conducted from December 2012 to December 2019 in 20 centres in France. Patients included at the principal investigator's center with available brain magnetic resonance imaging (MRI) at diagnosis were analyzed. MRI was reviewed by an experienced neuroradiologist blinded to clinical status. The size, topography and number of hyperintense lesions on diffusion-weighted imaging (DWI-HL) were analyzed at diagnosis and during follow-up. Outcomes involved descriptive characteristics of patients at onset and last follow-up. RESULTS: Twenty-three patients (38.1 [18.8-56.5] years, 16 females) were prospectively studied. The triad (i.e., brain, eye and ear involvement) was complete at onset in 17 patients. Brain MRI was performed 1.1 (0.1-3.4) months after the first symptom. All patients had DWI-HL at the acute phase. Patients were separated into two groups according to the number of DWI-HL on first MRI: a first group of patients (n=15) displaying low brain lesion load (<50 DWI-HL per patient) and a second group of patients (n=8) displaying high brain lesion load (≥100 DWI-HL). The median follow-up was 57.9 (9.7-98) months. Clinical features, treatment, relapse rate, time to disappearance of DWI-HL, disabilities and professional outcome did not differ according to brain lesion load. CONCLUSION: Brain lesion load assessed by DWI at the acute phase is not associated with risks of disability in SuS.

Cognitive dysfunction and brain atrophy in Susac syndrome.

BACKGROUND: Susac syndrome is a very rare cerebral small vessel disease, which can leave patients with cognitive impairment. We aimed at evaluating processing speed slowing, executive dysfunction and apathy and their relationships with whole brain and callosal atrophy. METHODS: Patients with Susac syndrome included in a prospective observational cohort study were evaluated, while clinically steady-state, with standardized brain MRI and a neuropsychological battery specifically designed to capture minimal cognitive alterations in non-disabled young patients. Brain volume and corpus callosum area were measured using 3D-T1 sequences, repeatedly overtime. Relationships between neuropsychological data and brain volumetric measures obtained the same day were tested with linear regression while controlling for sex, age, level of education, scores of depression and of apathy. RESULTS: Nineteen patients aged 37.5 ± 10.5 years were included. Mean follow-up time was 2.6 ± 1.3 years (5.8 ± 2.2 evaluations). While Montreal Cognitive Assessment scores were 25.1 ± 3.6, processing speed slowing was obvious (Trail Making Test version A: 43.1 ± 16.2 s; version B: 95.5 ± 67.9 s; reaction time: 314.6 ± 79.6 ms). Brain and corpus callosum atrophy was striking. No relationship was found between cognitive performances and brain volume or corpus callosum area. CONCLUSION: Patients with Susac syndrome show largely preserved global cognitive functions but important processing speed alterations. Although brain and corpus callosum area atrophy is prominent and evolving, we did not find any relationship with cognitive alterations, questioning the mechanisms underlying cognitive alterations in these patients. TRIAL REGISTRATION: Clinical Trial Registration-URL: https://www.clinicaltrials.gov Unique Identifier: NCT01481662.

Brain microvascular pathology in Susac syndrome: an electron microscopic study of five cases.

Susac syndrome is a rare, immune-mediated disease characterized by encephalopathy, branch retinal artery occlusion, and hearing loss. Herein, we describe the electron microscopic findings of three brain biopsies and two brain autopsies performed on five patients whose working clinical diagnosis was Susac syndrome. In all five cases, the key findings were basement membrane thickening and collagen deposition in the perivascular space involving small vessels and leading to thickening of vessel walls, narrowing, and vascular occlusion. These findings indicate that Susac syndrome is a microvascular disease. Mononuclear cells were present in the perivascular space, underlining the inflammatory nature of the pathology. Though nonspecific, the changes can be distinguished from genetic and acquired small vessel diseases. The encephalopathy of Susac syndrome overlaps clinically with degenerative and infectious conditions, and brain biopsy may be used for its diagnosis. Its vascular etiology may not be obvious on light microscopy, and electron microscopy is important for its confirmation.

Diagnosis and Prediction of Relapses in Susac Syndrome: A New Use for MR Postcontrast FLAIR Leptomeningeal Enhancement.

BACKGROUND AND PURPOSE: Leptomeningeal enhancement can be found in a variety of neurologic diseases such as Susac Syndrome. Our aim was to assess its prevalence and significance of leptomeningeal enhancement in Susac syndrome using 3T postcontrast fluid-attenuated inversion recovery MR imaging. MATERIALS AND METHODS: From January 2011 to December 2017, nine consecutive patients with Susac syndrome and a control group of 73 patients with multiple sclerosis or clinically isolated syndrome were included. Two neuroradiologists blinded to the clinical and ophthalmologic data independently reviewed MRIs and assessed leptomeningeal enhancement and parenchymal abnormalities. Follow-up MRIs (5.9 MRIs is the mean number per patient over a median period of 46 months) of patients with Susac syndrome were reviewed and compared with clinical and retinal fluorescein angiographic data evaluated by an independent ophthalmologist. Fisher tests were used to compare the 2 groups, and mixed-effects logistic models were used for analysis of clinical and imaging follow-up of patients with Susac syndrome. RESULTS: Patients with Susac syndrome were significantly more likely to present with leptomeningeal enhancement: 5/9 (56%) versus 6/73 (8%) in the control group (P = .002). They had a significantly higher leptomeningeal enhancement burden with ≥3 lesions in 5/9 patients versus 0/73 (P < .001). Regions of leptomeningeal enhancement were significantly more likely to be located in the posterior fossa: 5/9 versus 0/73 (P < .001). Interobserver agreement for leptomeningeal enhancement was good (κ = 0.79). There was a significant association between clinical relapses and increase of both leptomeningeal enhancement and parenchymal lesion load: OR = 6.15 (P = .01) and OR = 5 (P = .02), respectively. CONCLUSIONS: Leptomeningeal enhancement occurs frequently in Susac syndrome and could be helpful for diagnosis and in predicting clinical relapse.

Susac Syndrome: Clinical characteristics, diagnostic findings and treatment in 19 cases.

Susac's Syndrome (SS), which was first described in 1979, is a rare and presumably autoimmune disorder characterized by encephalopathy, hearing loss, and visual disturbance resulting from branch retinal artery occlusion (BRAO). This study reports 19 SS patients' clinical characteristics, MRI features, CSF analysis, treatment strategies and outcomes. At initial presentation, only three of 19 patients demonstrated the complete clinical triad. Clinic presentation varied from isolated hemiparesis to the full triad (encephalopathy, hearing loss and visual disturbances). Corpus callosum (CC) involvement was noted in the MRI of 18 patients (97%) and BRAO was detected in 17 (95%) patients. All patients were treated with intravenous methylprednisolone after the initial assessment. This case series is presented to emphasize the differences in clinical presentation of SS and the importance of MRI and FFA in diagnosis.

Neuropathological Findings in Susac Syndrome: An Autopsy Report.

A 24-year-old woman developed encephalopathy, branch retinal artery occlusion, hearing loss, and had "snowball" lesions in the corpus callosum, classic findings of Susac syndrome (SuS). Despite intensive immunosuppressive therapy, she lapsed into a coma, and died 7 months after the onset of her illness. Neuropathological examination, revealed perivascular inflammation and vasculitis involving small vessels, associated with vascular narrowing and occlusion, and numerous microinfarcts diffusely throughout the brain. The findings establish SuS as a neuroinflammatory condition that can include vasculitis. This represents the most comprehensive report of the neuropathological findings in SuS.

Clinical and imaging features distinguishing Susac syndrome from primary angiitis of the central nervous system.

INTRODUCTION: To assess clinical and/or imaging features useful to distinguish between Susac syndrome (SuS) and primary angiitis of central nervous system (PACNS). METHODS: Multicenter retrospective analysis of two cohorts of Argentine patients diagnosed with SuS and PACNS. RESULTS: 13 patients diagnosed with SuS (6 women and 7 men, mean age 35 ±â€¯10 years) and 15 with PACNS (10 women and 5 men, mean age 44 ±â€¯18 years) were analyzed. Cognitive impairment (11 out of 13 patients vs. 5 out of 15, p = .006), ataxia (7 out of 13 vs. 2 out of 15, p = .042) and auditory disturbances (7 out of 13 vs. 0 out of 15, p = .003) were more frequent in SuS patients; whereas seizures were more frequent in PACNS patients (8 out of 15 vs. 1 out of 13, p = .035). On MRI, corpus callosum (CC) involvement was observed more often in SuS, with abnormalities in CC genu, in 13 out of 13 SuS patients vs. only 2 out of 15 PACNS patients (p < .001); in CC body these were present in 13 out of 13 SuS patients vs. 1 out of 15 PACNS patients, (p < .001); and in CC splenium in 12 out of 13 Sus patients vs. 1 of 15 PACNS, p < .001). Cortical lesions were more frequent in PACNS patients (10 out of 15 vs. 3 out of 13 SuS patients, p = .02), as were hemorrhages (5 out of 15 vs. 0 out of 13 SuS, p = .04) and multiple basal ganglia infarcts (7 out of 15 vs. 1 out of 13 Sus, p = .037). CONCLUSION: Specific clinical and/or MRI findings may help distinguish SuS from PACNS with potential therapeutic implications.

Susac's syndrome: isolated retinal artery occlusion after 10 years of remission.

Susac's syndrome, or microangiopathy of the retina, inner ear, and brain, is a rare condition characterized by the clinical triad of encephalopathy, branch retinal artery occlusion, and sensorineural hearing loss. The complete triad has been documented in 85% of reported cases. At clinical onset, the most common manifestations are central nervous system symptoms, followed by visual symptoms and hearing disturbances. Although the clinical course of Susac's syndrome is usually self-limiting, fluctuating, and monophasic, clinical polycyclic and chronic courses have also been described. Likewise, recurrences of the full triad after more than 10 years of remission have been reported. We describe a 21-year-old woman who presented with branch retinal artery occlusions and magnetic resonance imaging findings compatible with Susac's syndrome without objective hearing loss. After 10 years of remission, the patient complained of visual field loss due to new retinal ischemia. Neither other symptoms nor neuroimaging or audiometry pathologic findings were found during the clinical course.

Susac's syndrome: isolated retinal artery occlusion after 10 years of remission / Síndrome de Susac: oclusão isolada da artéria retiniana após 10 anos de remissão

ABSTRACT Susac's syndrome, or microangiopathy of the retina, inner ear, and brain, is a rare condition characterized by the clinical triad of encephalopathy, branch retinal artery occlusion, and sensorineural hearing loss. The complete triad has been documented in 85% of reported cases. At clinical onset, the most common manifestations are central nervous system symptoms, followed by visual symptoms and hearing disturbances. Although the clinical course of Susac's syndrome is usually self-limiting, fluctuating, and monophasic, clinical polycyclic and chronic courses have also been described. Likewise, recurrences of the full triad after more than 10 years of remission have been reported. We describe a 21-year-old woman who presented with branch retinal artery occlusions and magnetic resonance imaging findings compatible with Susac's syndrome without objective hearing loss. After 10 years of remission, the patient complained of visual field loss due to new retinal ischemia. Neither other symptoms nor neuroimaging or audiometry pathologic findings were found during the clinical course.

RESUMO A síndrome de Susac, ou a micro angiopatia da retina, do ouvido interno e do cérebro, é uma condição rara caracterizada pela tríade clínica de encefalopatia, oclusão de ramo da artéria retiniana e perda de audição neuro-sensorial. A tríade completa é documentada em 85% dos casos registrados. No início dos sinais clínicos, a manifestação mais comum relaciona-se ao sistema nervoso central, seguida por sintomas visuais e distúrbios auditivos. Apesar do curso clínico da síndrome de Susac ser usualmente auto limitante, variável e monofásico, cursos clínicos policíclicos e crônicos têm sido também descritos. Do mesmo modo, recorrências da tríade completa após mais de 10 anos de remissão têm sido relatadas. Descrevemos o caso de uma mulher de 21 anos que apresentava oclusões de ramos da artéria retiniana e imagens por ressonância magnética compatíveis com a síndrome de Susac, sem comprometimento objetivo da audição. Dez anos após a remissão, a paciente queixou-se de perda de campo visual devido a uma nova isquemia da retina. Nenhum outro sintoma, ou neuroimagem ou achado audiométrico patológico foi observado durante o curso clínico.

Susac Syndrome: A differential diagnosis of white matter lesions.

INTRODUCTION: Susac Syndrome is an autoimmune endotheliopathy affecting capillaries and precapillary arterioles of the brain, inner ear and retina. The classic symptom triad includes visual disturbances, hypoacusia, and encephalopathy, but is rarely fully manifest at onset. The syndrome typically follows an active fluctuating monophasic course. Typical imaging findings on brain magnetic resonance show central fiber microischemias/microinfarctions of the corpus callosum known as "snow balls", as well as lineal infarcts and upper callosal fiber involvement. Fluorescein angiography and tonal audiometry are important tools to confirm diagnosis, even in patients who are asymptomatic for visual or auditory disturbances. We describe 8 patients with Susac Syndrome treated at our center and compare findings to those of other published case series. METHODS: Eight adults with Susac Syndrome diagnosed between January 2007 and August 2016 at our center, in Buenos Aires, Argentina are described. Magnetic Brain Resonance, fluorescein angiography, tonal audiometry, a complete serologic battery and lumbar puncture were performed to all patients. RESULTS: The majority of patients were males, and average age at diagnosis was 37.5 years (range: 22-52 yrs). Two patients presented full clinical triad at onset, while the remaining developed visual and/or auditory disturbances later during the course of disease. All cases manifested varied neurological symptoms including pyramidal and/or sensory tract symptoms, amnesic disorders, ataxia and vertigo. Psychiatric manifestations such as disinhibition, aggressive behavior, paranoid ideation and hallucinations were also present. Seven patients suffered at least one relapse. Typical central corpus callosum fiber ischemias/infarcts, also known as snowball lesions were visible in all patients. Spokes, icicles, periventricular lesions and internal capsule "string of beads" patterns were observed on diffusion weighted images. Four cases presented fornix microischemias/microinfarctions, 5 juxtacortical involvement and 3 infratentorial infarcts. Leptomeningeal involvement was evident in only 1 patient after rabies vaccination. Fluorescein angiography was abnormal in 7 cases. Tonal audiometry revealed unilateral hypoacusia in 5 patients, 3 with low frequency hearing loss. Immunosuppressive treatment was indicated in all cases. Patient follow up ranged between 6 months and 9 years, only 1 patient was lost to follow up after three years. CONCLUSION: Susac Syndrome is probably both underdiagnosed and misdiagnosed. Early and aggressive immunosuppressive treatment is indicated in order to prevent potential disabilities.

Neurological, otolaryngological and ophthalmological implications of Susac syndrome - a case report.

Susac syndrome is an endotheliopathy affecting the arterioles of the brain, retina, and inner ear. Many cases of Susac syndrome are underdiagnosed, mainly at the early stages of the disease, while prompt diagnosis enables a speedy recovery. Immediate treatment can halt disease progression and even prevent future disability. We report a case of Susac syndrome, describe the difficulties in the diagnosis of this case, and include a detailed history of a 35-year-old man via the presentation of extensive laboratory work-up and imaging studies. Audiometry showed sensorineural hearing loss of about 75 dB in the left ear. Ovoid lesions of the corpus callosum in magnetic resonance (MR) were present as were advanced binocular ophthalmological changes in fluorescent angiography. Methylprednisolone with acetylsalicylic acid and intravenous immunoglobulin (IVIG) were implemented with a positive outcome (clinical and audiometric improvement).

Neurocognitive Profile of a Woman with Susac's Syndrome: Further Evidence of Cognitive Variability.

OBJECTIVE: Susac's syndrome is a rare autoimmune disease characterized by encephalopathy, retinal artery occlusions, hearing loss, and lesions to the corpus callosum. To date, only four papers (five cases) have described the neuropsychological effects of the syndrome. Extant case reports of Susac's syndrome have documented varying levels of cognitive impairment; some studies have identified diffuse cerebral dysfunction, while others describe more focal impairments in attention, memory, and executive functioning. METHOD: The goal of this case study was to provide comprehensive neurocognitive data obtained from another case of confirmed Susac's syndrome. As such, we present the case of a 42-year-old woman with a two-year history of Susac's syndrome. At the time of the neuropsychological evaluation, the patient described ongoing difficulties with memory, word-finding problems, problems with math, and poor problem-solving. Physical/sensory changes included hearing loss, tinnitus, and migraines. RESULTS: Neuropsychological test results revealed the patient to be a woman of estimated average to high average premorbid intellect who exhibited a number of focal inefficiencies in the context of a generally intact profile. Particular cognitive weaknesses emerged on select tasks involving visuoconstruction, encoding of a wordlist, and bilateral speeded finger oscillations. She also committed three failures to maintain set on a task of cognitive flexibility. There was no evidence of memory deficits. CONCLUSIONS: Our findings provide further evidence of cognitive interindividual variability in a confirmed case of Susac's syndrome.