Risk factors for severe hearing loss in Susac syndrome: A national cohort study.

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.

Characteristics and management of Susac syndrome in an emergent country: a multi-center case series from Brazil.

BACKGROUND: Susac syndrome (SS) is a rare endotheliopathy with an estimated prevalence of 0.14-0.024 per 100,000. It is an important differential diagnosis in demyelinating disorders. There are few case series and no large randomized controlled trials, and most reports come from developed countries. We report six cases of SS in three centers in Brazil and discuss management challenges in emergent countries. METHODS: This is a retrospective case series of patients diagnosed with SS in three medical centers in Brazil between April 2018 and July 2021. The European Susac consortium (EuSaC) criteria were used for diagnosis of SS. Demographic data and clinical interventions were described and outcomes were assessed subjectively and by applying the modified Rankin Scale (mRS) on last follow-up. RESULTS: Six patients were diagnosed with SS (3 males, 3 females). Mean age at presentation was 36 years (range 17 to 54). The most common initial symptom was confusion, followed by visual impairment and hearing loss. Characteristic snowball lesions on magnetic resonance imaging (MRI) were present in four patients (66%). Retinal artery abnormalities were present in half (3/6) of patients, and sensorineural hearing loss was present in four patients (66%). Outcome was favorable (mRS ≤ 2) in five patients (86%). Patients treated early had a more favorable outcome. CONCLUSION: Emergent countries face challenges in the diagnosis and management of patients with SS, such as access to advanced tests (fluorescein angiography, serial MRI) and treatment drugs (rituximab, mycophenolate). Further research should consider particularities of patients with SS in emergent countries.

[Update on Susac syndrome]. / Actualités dans le syndrome de Susac.

Susac syndrome is a rare disease affecting mainly young women, characterized by a microangiopathy limited to the cerebral, retinal, and cochlear vessels. Although the pathophysiology of Susac syndrome is not yet fully elucidated, recent advances favour a primitive vasculitis affecting the cerebral, retinal and cochlear small vessels. Susac syndrome must be recognized in the presence of the pathognomonic clinical triad associating: 1/subacute encephalopathy with unusual headache and pseudopsychiatric features associated with diffuse white matter, grey matter nuclei and specifically corpus callosum lesions on brain MRI; 2/eye involvement that may be pauci-symptomatic, with occlusions of the branches of the central artery of the retina at fundoscopy and arterial wall hyperfluorescence on fluorescein angiography; and 3/cochleo-vestibular damage with hearing loss predominating at low frequencies on the audiogram. Relapses are frequent during an active period lasting approximately 2 years. Eventually, the disease resolves but isolated retinal arterial wall hyperfluorescence without new occlusions may recur, which should not lead to treatment intensification. First-line treatment consists of a combination of anti-aggregants and high dose corticosteroids. In refractory patients or in case of relapse, immunomodulatory molecules such as intravenous immunoglobulins or immunosuppressive drugs such as mycophenolate mofetil, cyclophosphamide or rituximab should be started. Unfortunately, sequelae-mostly hearing loss- remain frequent in these young patients.

Susac's syndrome: clinical course and epidemiology in a Central European population.

OBJECTIVE: Susac's syndrome is characterized by inflammation and occlusion of pre-capillary arterioles with the clinical triad of branch retinal artery occlusion (BRAO), encephalopathy and hearing loss. No epidemiological data are available for the disease. METHODS: All neurology departments in Austria were addressed to report adult patients who were on immunosuppressive treatment for a diagnosis of Susac's syndrome between 1 August 2010 and 1 August 2015. Clinical course, treatment regimens, period and point prevalence rates, and annual incidence of Susac's syndrome in Austria in people over 19 years of age are reported. RESULTS: Ten patients with Susac's syndrome were identified, and eight of them were newly diagnosed within the five-year timeframe. Minimum five-year period prevalence of the disease is 0.148/100,000 (95% confidence interval (CI) 0.071-0.272), annual incidence is 0.024/100,000 (95% CI 0.010-0.047). Minimum point prevalence rates varied from 0.030/100,000 (95% CI 0.004-0.108) to 0.088/100,000 (95% CI 0.032-0.192). Of all 10 patients, 8 showed typical callosal or internal capsule magnetic resonance imaging lesions at first presentation, 7 presented with BRAO and 5 had hearing loss or tinnitus at the beginning of the disease. Four patients developed the complete clinical triad of Susac's syndrome during the observation period. CONCLUSIONS: We provide for the first time population-based data about the clinical course, prevalence and incidence of Susac's syndrome.

Susac's syndrome--pathogenesis, clinical variants and treatment approaches.

Susac's syndrome is a rare disease that is characterised by the clinical triad of encephalopathy, branch retinal artery occlusion, and sensorineural hearing loss. It was first described as a distinctive syndrome by Susac in 1979. There have been 304 reported individual patients with Susac's syndrome. Etiopathogenesis is not clear, although it is now thought that it is an immune-mediated endotheliopathy that affects the microvasculature of the brain, retina, and inner ear. Antiendothelial cell antibodies (AECAs) play an important role in mediating the endothelial cell injury with consequent deposition of thrombotic material in the lumen of the small vessel. In biopsies of the brain, microinfarcts with atrophy of the white and grey matter could be detected. These microinfarcts are caused by a microangiopathic process with arteriolar wall proliferation, lymphocytic infiltration and basal lamina thickening. At clinical onset, the most common manifestation was central nervous system symptoms, followed by visual symptoms and hearing disturbances. Diagnosis is based on Magnetic Resonance Imaging (MRI), retinal fluorescein angiography, and audiometry; these are considered crucial tests to enable diagnosis. Antiendothelial cell antibodies (AECAs) are also of diagnostic relevance. Based on the hypothesis of being an autoimmune disease, treatment has to be immunosuppressive. In addition, anticoagulation measures, antiplatelet agents and antivasospastic agents should be considered. The majority of patients did not initially present with the complete triad of symptoms. An appropriate approach would be to perform a search for absent components of the triad if the clinical presentation is suggestive of Susac's syndrome. Improved understanding of the presentation of Susac's syndrome will prevent misdiagnosis and ensure that patients receive the best possible care.

Diagnosis and classification of Susac syndrome.

Susac syndrome (SS) is an autoimmune disease characterized by the clinical triad of encephalopathy, branch retinal artery occlusions and neuro-sensorial hearing loss; it is due to a microangiopathy affecting the precapillary arterioles of the brain, retina and inner ear. SS is characterized by typical radiological features on magnetic resonance imaging (MRI) which, together with clinical symptoms, may permit a diagnosis. Branch retinal artery occlusions (BRAOs) are best evaluated using fluorescein angiography (FA) which may show the typical multifocal fluorescence. SS is an autoimmune endotheliopathy that requires treatment with immunosuppressive agents: steroids, azathioprine, mycophenolate mofetil, methotrexate, cyclophosphamide and intravenous immunoglobulin, usually in combination. Plasma exchange is also useful. In addition, antiplatelet agents may be a useful adjunct. Correct immunosuppressive therapy results in significant clinical and radiological improvement. An early diagnosis and treatment are important to delay the disease progression and prevent permanent disability.

Characteristics of Susac syndrome: a review of all reported cases.

In Susac syndrome, occlusions of microvessels--presumed to be mediated by an autoimmune response to an as yet unknown antigen--lead to a characteristic clinical triad of CNS dysfunction, branch retinal artery occlusions, and sensorineural hearing impairment. Susac syndrome is considered a rare but important differential diagnosis in numerous neurological, psychiatric, ophthalmological, and ear, nose and throat disorders. Improved understanding of this disorder is crucial, therefore, to ensure that patients receive appropriate treatment and care. Current knowledge on Susac syndrome is largely based on reports of single patients, small case series, and nonsystematic reviews. The aim of this Review is to extend these previous, primarily anecdotal findings by compiling data from all 304 cases of Susac syndrome that have been published worldwide, which were identified following a literature search with predefined search, inclusion and exclusion criteria. From this data, we present an overview of demographic, clinical and diagnostic data on Susac syndrome, providing a reliable basis for our current understanding of this rare disease. Where possible, we make recommendations for clinical diagnosis, differential diagnosis, and management of patients with suspected Susac syndrome.

Susac's syndrome: an update.

Susac's syndrome is an infrequent neurological disorder characterized by the clinical triad of encephalopathy, hearing loss, and branch retinal artery occlusions. Its pathophysiology is not entirely clear, although it is now thought that it is most probably an immune-mediated endotheliopathy that affects the microvasculature of the brain, retina, and inner ear. An early diagnosis is important as treatment can halt disease progression and prevent permanent disability.