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.

High efficacy of rituximab for myasthenia gravis: a comprehensive nationwide study in Austria.

BACKGROUND: Most patients with myasthenia gravis (MG) need long-term immunosuppressive therapy. However, conventional agents may have intolerable side effects, take too long or fail to achieve disease control. Rituximab (RTX) has emerged as an off-label treatment for refractory MG, but data on its use are still sparse. METHODS: We conducted a retrospective nationwide study contacting all Austrian neurologists to provide anonymized data of all adult MG patients treated with RTX and minimum follow-up of 3 months. The Myasthenia Gravis Foundation of America Postintervention Status scale was used to assess outcomes. RESULTS: 34 (60.7%) of a total of 56 patients were women. Median (IQR) age at diagnosis of MG and start of RTX were 41.5 (24.3; 65.8) and 47.5 (33; 71) years, respectively. Antibodies (ab) against acetylcholine receptor (AchR) and muscle-specific tyrosine kinase (MuSK) were present in 69.6% and 25% of patients, respectively (seronegative: 5.4%). Before RTX, 47 (83.9%) patients had had plasma exchange, immune adsorption or immunoglobulins. Three months after RTX, 14 of 53 (26.4%) patients were in remission. At last follow-up after a median of 20 (10; 53) months, remission was present in 42.9% of patients and another 25% had minimal manifestations. Remission was more frequent in patients with MuSK ab vs. those with AchR ab (71.4% vs. 35.9%, p = 0.022). RTX was safe. The presence of MuSK ab independently predicted remission after RTX. CONCLUSION: In this retrospective study on RTX for MG, the largest to date, RTX appeared safe, efficacious and fast acting. Benefit from RTX was greatest in MuSK ab + MG.

Neuromyelitis optica in Austria in 2011: to bridge the gap between neuroepidemiological research and practice in a study population of 8.4 million people.

BACKGROUND: In 2008 the Austrian Task Force for Neuromyelitis Optica (NMO) started a nation-wide network for information exchange and multi-centre collaboration. Their aim was to detect all patients with NMO or NMO spectrum disorders (NMO-SD) in Austria and to analyse their disease courses and response to treatment. METHODS: (1) As of March 2008, 1957 serum samples (of 1557 patients) have been tested with an established cell based immunofluorescence aquaporin-4 antibody (AQP4-ab) assay with a high sensitivity and specificity (both >95%). All tests were performed in a single reference laboratory (Clinical Dept. of Neurology of the Innsbruck Medical University). (2) A nation-wide survey with several calls for participation (via email newsletters, articles in the official journal of the Austrian Society of Neurology, and workshops) was initiated in 2008. All collected data will be presented in a way that allows that every individual patient can be traced back in order to ensure transparency and to avoid any data distortion in future meta-analyses. The careful and detailed presentation allows the visualization and comparison of the different disease courses in real time span. Failure and response to treatment are made visible at one glance. Database closure was 31 December 2011. All co-operators were offered co-authorship. RESULTS: All 71 NMO- or NMO-SD patients with AQP4-ab positivity (age range 12.3 to 79.6 years) were analysed in detail. Sex ratio (m:f = 1:7) and the proportion of patients without oligoclonal bands in cerebrospinal fluid (86.6%) were in line with previously published results. All identified patients were Caucasians. CONCLUSIONS: A nationwide collaboration amongst Austrian neurologists with good network communications made it possible to establish a database of 71 AQP4-ab positive patients with NMO/NMO-SD. This database is presented in detail and provides the basis for further studies and international cooperation in order to investigate this rare disease.