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.

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.

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.

[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.

Encephalopathic Susac's Syndrome associated with livedo racemosa in a young woman before the completion of family planning.

BACKGROUND: Susac's Syndrome (SS) consists of the triad of encephalopathy, branch retinal artery occlusions (BRAO) and hearing loss (HL). Histopathologically, SS is characterised by a microangiopathy, and some observations suggest that an immune-mediated damage of endothelial cells might play a role. These findings also implicate a similarity between SS and other autoimmune diseases, most notably juvenile dermatomyositis (JDM). However, SS and JDM are commonly thought to affect distinct and non-overlapping sets of organs, and it is currently not clear how these specificities arise. Moreover, in the absence of clinical trials, some authors suggest that therapeutic approaches in SS should rely on the model of other autoimmune diseases such as JDM. CASE PRESENTATION: Here, we report a case of SS in a 32-year-old pregnant woman. She initially was admitted to the hospital with subacute severe encephalopathy and multifocal neurologic signs. As cranial magnetic resonance imaging (MRI) revealed multifocal white matter lesions including the corpus callosum, erroneously a diagnosis of multiple sclerosis (MS) was made, and intravenous methylprednisolone (IVMP) therapy was initiated. A few days later, an exanthema appeared on the trunk and extremities, which was diagnosed as livedo racemosa (LR). Several weeks later, the patient was readmitted to the clinic with an obscuration of her left visual hemifield and a bilateral HL. Ophthalmologic examination revealed extensive ischemic damage to both retinae. Now the correct diagnosis of SS was established, based on the above triad of clinical symptoms in conjunction with typical MRI and fundoscopic findings. When SS was diagnosed, the standard therapy with intravenous cyclophosphamide (IVCTX) was not instituted because of a significant risk of permanent infertility. Instead, sustained control of disease activity could be achieved with a therapeutic regime combining prednisolone, intravenous immunoglobulins (IVIG), mycophenylate mofetil (MM), and methotrexate (MTX). CONCLUSIONS: An association with LR has only been described in very few cases of SS before and further underlines the pathogenetic relationship between SS and other autoimmune diseases such as JDM. In young women with SS and the desire for a child the combination of MM and MTX may represent a reasonable alternative to IVCTX.

Susac's Syndrome: A Case Presentation and Radiological Approach to this Rare Autoimmune Endotheliopathy.

Susac's syndrome is an uncommon neurologic disorder, consisting of the clinical triad of encephalopathy, branch retinal artery occlusions, and hearing loss. We report a case of a sudden vision and hearing impairment in a 35-year-old female patient. Magnetic resonance imaging of the brain revealed multiple lesions in the white matter and the corpus callosum, typical of Susac's syndrome.

Susac syndrome. A differential diagnosis for demyelination.

Susac syndrome is a microangiopathy of unknown origin, probably autoimmune, affecting capillaries and precapillary arterioles of the brain, retina, and inner ear. It is often misdiagnosed as acute disseminated encephalomyelitis or multiple sclerosis. We report the case of a 25-year-old male with Susac syndrome who developed the clinical triad of encephalopathy, visual and hearing problems over the course of a year. The characteristic MRI findings including central corpus callosal involvement and brain infarctions were supported by branch retinal arterial/arteriolar occlusions on fluorescein retinal angiography. Most patients with Susac syndrome will not have the complete clinical triad initially. A very high index of suspicion is required by the clinician and radiologist in patients with any component of the clinical triad so as not to misdiagnose the MRI findings for demyelination. Even if initial ophthalmologic examinations are normal, these patients should be followed up for later development of branch retinal artery occlusions.

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.

Lesion morphology at 7 Tesla MRI differentiates Susac syndrome from multiple sclerosis.

BACKGROUND: Although an orphan disease with still obscure aetiopathogenesis, Susac syndrome has to be considered as differential diagnosis in multiple sclerosis (MS), since its clinical presentation and paraclinical features including routine magnetic resonance imaging (MRI) findings partially overlap. OBJECTIVE: We aimed to study a potential benefit of 7T MRI for (i) the differentiation between Susac syndrome and MS and (ii) the clarification of pathogenesis of Susac syndrome. METHODS: Five patients suffering from Susac syndrome, 10 sex- and age-matched patients with relapsing-remitting MS (median Expanded Disability Status Scale (EDSS) score 1.5) and 15 matching healthy controls were investigated at 7 Tesla MRI. The protocol included T1-weighted MPRAGE, T2*-weighted FLASH, and TIRM sequences. RESULTS: Almost all T2* FLASH lesions in patients with MS were centred by a small central vein (325 lesions; 92%) and often showed a small hypointense rim (145 lesions; 41%). In contrast, white matter lesions in Susac syndrome exhibited a perivascular setting significantly less frequently (148 lesions; 54%, p=0.002), and very rarely exhibited a hypointense rim (12 lesions; 4%, p=0.004). Furthermore, in addition to callosal atrophy, Susac patients showed cerebrospinal fluid-isointense lesions within the central part of corpus callosum that are not commonly seen in MS. CONCLUSION: At 7T MRI, plaques in MS patients and patients with Susac syndrome differed substantially with respect to morphology and pattern. Thus, lesion morphology at 7T (i) may serve as a marker to distinguish Susac syndrome from MS and (ii) reflects a different pathophysiological mechanism underlying Susac syndrome, for example microinfarction rather than demyelination.

Recurrent bilateral branch retinal artery occlusion with hearing loss and encephalopathy: the first case report of Susac syndrome in Korea.

We report the first case of Susac syndrome in Koreans, in a 23-yr-old female patient who presented with sudden visual loss and associated neurological symptoms. Ophthalmic examination and fluorescein angiography showed multiple areas of branch retinal artery occlusion, which tended to recur in both eyes. Magnetic resonance imaging showed dot-like, diffusion-restricted lesions in the corpus callosum and left fornix, and audiometry showed low-frequency sensory hearing loss, compatible with Susac syndrome. She received immunosuppressive therapy with oral steroid and azathioprine. Three months later all the symptoms disappeared but obstructive vasculitis have been relapsing. This patient demonstrated the entire clinical triad of Susac syndrome, which tends to occur in young females. Although this disorder has rarely been reported in Asian populations, a high index of suspicion is warranted for early diagnosis and timely treatment.

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.

Susac syndrome: a case report and PET imaging findings.

We describe the case of a twenty-year-old woman with subacute encephalopathy, who subsequently developed hearing loss and ophtalmopathy. The clinical triad and typical findings on magnetic resonance imaging and cerebrospinal fluid analysis led to the diagnosis of Susac syndrome. Brain positron emission tomography showed abnormalities which are comparable with other types of central nervous system vasculitis, and distinct from those found in multiple sclerosis.

[Susac syndrome, retinocochleocerebral microangiopathy: contribution of MRI]. / Le syndrome de Susac, microangiopathie rétinocochléocérébrale : apport de l'IRM.

This is a new case of Susac syndrome in a 27-year-old woman with polymorphic neurological disorders, her brain MRI showed multifocal hyperintense signals on T2-weighted images with possible effects on the corpus callosum. However, visualization of an occlusion in the retinal arterial branch of the right eye and hypoacusia on the right side allowed confirmation of the diagnosis. In this case report, we describe the imaging aspects of Susac syndrome and demonstrate that brain MRI allows the syndrome to be diagnosed at an early stage.

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.

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.