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).
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.
CONCLUSIONS: 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.
UNASSIGNED: HINTERGRUND: Das Susac-Syndrom (SS) stellt eine Endotheliopathie der Gefäße im Bereich des zentralen Nervensystems dar. Die Beteiligung der Netzhaut spielt in der Krankheitsmanifestation eine zentrale Rolle.
UNASSIGNED: Ziel dieser Fall-Kontroll-Studie ist die Untersuchung der makulären Gefäßstruktur bei Patienten mit chronischem SS im Vergleich zu Kontrollpersonen mittels optischer Kohärenztomographie Angiographie (OCTA).
METHODS: Es wurden 12 Augen von 12 Susac-Patienten mit altersgleichen gesunden Kontrollpersonen hinsichtlich ihrer OCT-angiographischen Parameter verglichen. Die Flussdichte (FD) verschiedener makulärer Schichten, Parameter der fovealen avaskulären Zone (FAZ) sowie die Werte der zentralen Netzhautdicke und des zentralen Netzhautvolumens wurden zwischen den beiden Gruppen verglichen.
UNASSIGNED: Die FD-Werte der Choriokapillaris waren in Susac-Patienten im Vergleich zu gesunden Kontrollen signifikant verringert. Die FD-Werte des oberflächlichen und tiefen Kapillarplexus der inneren Netzhaut, die Parameter der FAZ sowie die zentrale Netzhautdicke und -volumen zeigten keine signifikanten Unterschiede zwischen den beiden Gruppen.
CONCLUSIONS: Das therapierte, chronische SS scheint keinen signifikanten Einfluss auf den vaskulären und strukturellen Aufbau der zentralen, inneren Netzhaut zu haben. Unterschiede der Choriokapillaris deuten jedoch auf Veränderungen in tiefer liegenden, stark vaskularisierten Kapillarschichten hin.

OBJECTIVE: Susac syndrome (SuS) is a rare, autoimmune, neurological disease characterized by a clinical triad of branch retinal artery occlusion, sensorineural hearing loss and encephalopathy. Neuropsychological functioning in SuS is little researched and the prevalence, nature, and evolution over time of cognitive deficits in SuS remain unclear. This study aimed to better understand the long-term neuropsychological outcomes of patients with SuS.
METHODS: Thirteen patients with SuS (mean [SD] age 39.5 [11.1] years) were enrolled at the Ghent University Hospital by their treating neurologist. The cognitive functioning and emotional well-being of each patient was evaluated by means of a thorough neuropsychological test battery at baseline and after 2 years. Follow-up testing after 2 years was performed in 11 patients (mean [SD] age 42.2 [11.5] years).
RESULTS: Patients showed normal neuropsychological test results at a group level, both at baseline and follow-up testing. Significant improvements over time were found for information processing speed, verbal recognition, and semantic and phonological fluency. Individual test results showed interindividual variability at baseline, with most impairments being in attention, executive functioning and language, which improved after a 2-year period. In addition, patients reported significantly lower mental and physical well-being, both at baseline and follow-up testing.
CONCLUSIONS: Our results suggest that neuropsychological dysfunction in SuS is limited at a group level and improves over time. Nonetheless, individual test results reveal interindividual variability, making cognitive screening essential. Furthermore, a high psycho-emotional burden of the disease was reported, for which screening and follow-up are necessary.

BACKGROUND: Nonreversible hearing loss (HL) is the main sequelae of Susac syndrome (SuS). We aimed to identify risk factors for HL in SuS.
METHODS: The CARESS study is a prospective national cohort study that started in December 2011, including all consecutive patients with SuS referred to the French reference center. The CARESS study was designed with a follow-up including fundoscopy, audiometry, and brain magnetic resonance imaging at 1, 3, 6, and 12 months after diagnosis and then annually for 5 years. The primary outcome was the occurrence at last follow-up of severe HL defined as the loss of 70 dB in at least one ear on audiometry or the need for hearing aids.
RESULTS: Thirty-six patients (female 66.7%, median age 37.5 [range 24.5-42.5] years) included in the clinical study were analyzed for the primary outcome. Thirty-three patients (91.7%) had cochleovestibular involvement at SuS diagnosis including HL >20 dB in at least one ear in 25 cases. At diagnosis, 32 (88.9%), 11 (30.6%), and 7 (19.4%) patients had received steroids, intravenous immunoglobulin, and/or immunosuppressive (IS) drugs, respectively. After a median follow-up of 51.8 [range 29.2-77.6] months, 19 patients (52.8%) experienced severe HL that occurred a median of 13 [range 1.5-29.5] months after diagnosis. Multivariable analysis showed that the odds of severe HL were lower in patients who received IS drugs at diagnosis (OR 0.15, 95% CI 0.01-1.07, p = 0.058).
CONCLUSIONS: Severe HL in SuS is associated with the absence of IS drugs given at diagnosis. Our findings support the systematic use of IS drugs in SuS.

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.
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.
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.
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.

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.
CONCLUSIONS: Brain lesion load assessed by DWI at the acute phase is not associated with risks of disability in SuS.

BACKGROUND: Susac syndrome (SuS) is a rare condition characterized by a clinical triad of sensorineural hearing loss, branch artery occlusion and encephalopathy. This study reports an increased incidence of SuS in Israel. We describe the clinical characteristics of these patients, diagnostic procedures and the use and subsequent outcomes of newly published treatment guidelines.
METHODS: This is a single center retrospective study. Patients who were diagnosed with SuS between July 2017 and August 2018 were enrolled in this study.
RESULTS: Seven patients were diagnosed with SuS according to the diagnostic criteria in a time period of 13 months. The annual incidence was recently evaluated in Austria to be 0.024/100000, therefore, our case series represent at least a 5.4- fold increase in the annual incidence of SuS expected in Israel and a 7-fold increase in the annual incidence expected in our medical center. Mean time from the onset of the symptoms to diagnosis was three weeks and follow-up time was twenty four months. Recent exposure to cytomegalovirus was serologically evident in three patients and one patient had high titer of anti-streptolysin antibody. All patients underwent brain MRI, fluorescein angiography and audiometry. All patients were treated according to the newly recommended guidelines. All patients achieved clinical and radiological stability.
CONCLUSIONS: We report of an increased incidence of SuS in Israel. Infectious serological findings may imply a post infectious mechanism. The use of the recommended diagnostic procedures reduced the time to diagnosis. Newly published treatment guidelines led to favorable clinical outcomes.

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.

Susac syndrome is a rare condition characterised by the clinical triad of encephalopathy, branch retinal artery occlusion, and sensorineural hearing loss. Of the few published cases, there is variability with regard to cognitive outcome. We describe the clinical course and neuropsychological performance of a 21-year-old male patient presenting with severe encephalopathy and later developing the full triad fulfilling the diagnosis of Susac syndrome.

BACKGROUND: Susac syndrome (SuS) is a rare disorder thought to be caused by autoimmune-mediated occlusions of microvessels in the brain, retina and inner ear leading to central nervous system (CNS) dysfunction, visual disturbances due to branch retinal artery occlusions (BRAO), and hearing deficits. Recently, a role for anti-endothelial cell antibodies (AECA) in SuS has been proposed.
OBJECTIVE: To report the clinical and paraclinical findings in the largest single series of patients so far and to investigate the frequency, titers, and clinical relevance of AECA in SuS.
METHODS: A total of 107 serum samples from 20 patients with definite SuS, 5 with abortive forms of SuS (all with BRAO), and 70 controls were tested for AECA by immunohistochemistry employing primate brain tissue sections.
RESULTS: IgG-AECA >1:100 were detected in 25% (5/20) of patients with definite SuS and in 4.3% (3/70) of the controls. Median titers were significantly higher in SuS (1:3200, range 1:100 to 1:17500) than in controls (1:100, range 1:10 to 1:320); IgG-AECA titers >1:320 were exclusively present in patients with SuS; three controls had very low titers (1:10). Follow-up samples (n = 4) from a seropositive SuS patient obtained over a period of 29 months remained positive at high titers. In all seropositive cases, AECA belonged to the complement-activating IgG1 subclass. All but one of the IgG-AECA-positive samples were positive also for IgA-AECA and 45% for IgM-AECA. SuS took a severe and relapsing course in most patients and was associated with bilateral visual and hearing impairment, a broad panel of neurological and neuropsychological symptoms, and brain atrophy in the majority of cases. Seropositive and seronegative patients did not differ with regard to any of the clinical or paraclinical parameters analyzed.
CONCLUSIONS: SuS took a severe and protracted course in the present cohort, resulting in significant impairment. Our finding of high-titer IgG1 and IgM AECA in some patients suggest that humoral autoimmunity targeting the microvasculature may play a role in the pathogenesis of SuS, at least in a subset of patients. Further studies are warranted to define the exact target structures of AECA in SuS.

Patient NC showed impairment on several tasks making use of coordinate spatial information, while categorical processing was at control level. Her assessment of local and global features of visual stimuli indicated that she had a local bias of attention, whereas controls showed a global bias. Her problems with coordinate tasks can be explained by this reduced global attentional focus. These findings confirm previous reports suggesting that the processing of categorical spatial relations benefits from a small scope of attention, whereas a relatively large scope of attention enhances coordinate spatial relation processing.