Background To investigate the frequency and characterize the clinical features of treatment-refractory myasthenia gravis in an Austrian cohort. Methods Patient charts of 126 patients with generalized myasthenia gravis and onset between 2000 and 2016 were analyzed retrospectively. Patients were classified as treatment-refractory according to strict, predefined criteria. These mandated patients being at least moderately symptomatic (i.e., MGFA class III) or needing either maintenance immunoglobulins or plasma exchange therapy for at least 1 year in spite of two adequately dosed immunosuppressive drugs. Clinical features and outcome at last follow-up were compared to treatment-responsive patients. Results 14 out of 126 patients (11.1%) met these criteria of treatment-refractory myasthenia gravis. Treatment-refractory patients had more frequent clinical exacerbations and more often received rescue treatments or a further escalation of immunosuppressive therapies. They also remained more severely affected at last follow-up. An early onset of myasthenia gravis was associated with a higher risk for a refractory course. Conclusion A small subgroup of patients with generalized myasthenia gravis do not respond sufficiently to standard therapies. Refractory disease has considerable implications for both patients and health care providers and highlights an unmet need for new treatment options.

Objective:To describe disease outcomes of myasthenia gravis (MG) subgroups and which factors influence outcomes by reviewing individual patient records of a representative cohort.Methods:We performed a retrospective analysis of 199 patients with generalized MG and a disease onset after the year 2000, who were treated at two tertiary referral centers in Austria. We stratified patients into early and late onset AChR-ab positive, MuSK-ab positive, seronegative patients and patients with thymoma regardless of antibody status. We evaluated patients’ symptom severity, treatment regimens and occurrence of life threatening events at yearly time points for up to ten years.Results:Minimal manifestation status or better was eventually achieved and sustained for longer than one year by 125 (63%) patients. 40% (66 of 165 patients) showed an early response to treatment, which predicted a benign disease course later on. In contrast, 19% of patients, who remained symptomatic for two years after disease onset despite immunosuppressive therapy, were more treatment resistant in the following years. The strongest predictor of outcome was the diagnostic subgroup. MuSK-MG had a much better outcome than previously reported.Conclusion:Our data give an update on the disease course of generalized myasthenia gravis in the new century. Diagnostic subgroups and response to treatment within the first two years help to predict the long term outcome.

Background and purposeNext‐generation sequencing has greatly improved the diagnostic success rates for genetic neuromuscular disorders (NMDs). Nevertheless, most patients still remain undiagnosed, and there is a need to maximize the diagnostic yield.MethodsA retrospective study was conducted on 72 patients with NMDs who underwent exome sequencing (ES), partly followed by genotype‐guided diagnostic reassessment and secondary investigations. The diagnostic yields that would have been achieved by appropriately chosen narrow and comprehensive gene panels were also analysed.ResultsThe initial diagnostic yield of ES was 30.6% (n = 22/72 patients). In an additional 15.3% of patients (n = 11/72) ES results were of unknown clinical significance. After genotype‐guided diagnostic reassessment and complementary investigations, the yield was increased to 37.5% (n = 27/72). Compared to ES, targeted gene panels (<25 kilobases) reached a diagnostic yield of 22.2% (n = 16/72), whereas comprehensive gene panels achieved 34.7% (n = 25/72).ConclusionExome sequencing allows the detection of pathogenic variants missed by (narrowly) targeted gene panel approaches. Diagnostic reassessment after genetic testing further enhances the diagnostic outcomes for NMDs.

The development of the neuromuscular synapse depends on signaling processes that involve protein phosphorylation as a crucial regulatory event. Muscle-specific kinase (MuSK) is the key signaling molecule at the neuromuscular synapse whose activity is required for the formation of a mature and functional synapse. However, the signaling cascade downstream of MuSK and the regulation of the different components are still poorly understood.In this study we used a quantitative phosphoproteomics approach to study the phosphorylation events and their temporal regulation downstream of MuSK. We identified a total of 10,183 phosphopeptides, of which 203 were significantly up-or down-regulated. Regulated phosphopeptides were classified into four different clusters according to their temporal profiles. Within these clusters we found an overrepresentation of specific protein classes associated with different cellular functions. In particular, we found an enrichment of regulated phosphoproteins involved in posttranscriptional mechanisms and in cytoskeletal organization. These findings provide novel insights into the complex signaling network downstream of MuSK and form the basis for future mechanistic studies. Molecular & Cellular

Objective To analyze characteristics associated with long-term pain relief after microvascular decompression (MVD) for trigeminal neuralgia (TGN). Description of associated morbidity and complication avoidance. Methods One hundred sixty-five patients with TGN underwent 171 MVD surgeries at the authors’ institution. Patient characteristics and magnetic resonance imaging (MRI) datasets were obtained through the hospital’s archiving system. Patients provided information about pre- and post-operative pain characteristics and neurologic outcome. Favorable outcome was defined as a Barrow Neurological Institute (BNI) pain intensity score of I to III with post-operative improvement of I grade. Results Type of TGN pain with purely paroxysmal pain (p = 0.0202*) and TGN classification with classical TGN (p = 0.0372*) were the only significant predictors for long-term pain relief. Immediate pain relief occurred in 90.6% of patients with a recurrence rate of 39.4% after 3.5 ± 4.6 years. MRI reporting of a neurovascular conflict had a low negative predictive value of 39.6%. Mortality was 0% with major complications observed in 8.2% of patients. Older age was associated with lower complication rates (p = 0.0009***). Re-MVD surgeries showed improved long-term pain relief in four out of five cases. Conclusions MVD is a safe and effective procedure even in the elderly. It has the unique potential to cure TGN if performed on a regular basis, and if key surgical steps are respected. Early MVD should be offered in case of medical treatment failure and paroxysmal pain symptoms. The presence of a neurovascular conflict on MRI is not mandatory. In case of recurrence, re-MVD is a good treatment option that should be discussed with patients. Highlights • Long-term analysis of pain relief after MVD. • Positive predictors for outcome: classical TGN and purely paroxysmal pain. • Presence of neurovascular conflict in MRI is not mandatory for MVD surgery. • Analysis of complications and surgical nuances for avoidance. • MVD is a safe procedure also in the elderly.