The Role of Sugammadex in Symptomatic Transient Neonatal Myasthenia Gravis: A Case Report.

We describe the case of a 3-week-old boy with pyloric stenosis who presented for laparoscopic pyloromyotomy in the setting of symptomatic transient neonatal myasthenia gravis. The patient received muscle relaxation with rocuronium, and neuromuscular blockade was successfully reversed with sugammadex with recovery guided by train-of-four monitoring. He was extubated uneventfully without complications. Because sugammadex binds directly to rocuronium rather than interfering with acetylcholine metabolism, it might provide a good option for reversal of neuromuscular blockade in transient neonatal myasthenia gravis.

Ephedrine for myasthenia gravis, neonatal myasthenia and the congenital myasthenic syndromes.

BACKGROUND: Myasthenia is a condition in which neuromuscular transmission is affected by antibodies against neuromuscular junction components (autoimmune myasthenia gravis, MG; and neonatal myasthenia gravis, NMG) or by defects in genes for neuromuscular junction proteins (congenital myasthenic syndromes, CMSs). Clinically, some individuals seem to benefit from treatment with ephedrine, but its effects and adverse effects have not been systematically evaluated. OBJECTIVES: To assess the effects and adverse effects of ephedrine in people with autoimmune MG, transient neonatal MG, and the congenital myasthenic syndromes. SEARCH METHODS: On 17 November 2014, we searched the Cochrane Neuromuscular Disease Group Specialized Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and EMBASE. We also searched reference lists of articles, conference proceedings of relevant conferences, and prospective trial registers. In addition, we contacted manufacturers and researchers in the field. SELECTION CRITERIA: We considered randomised controlled trials (RCTs) and quasi-RCTs comparing ephedrine as a single or add-on treatment with any other active treatment, placebo, or no treatment in adults or children with autoimmune MG, NMG, or CMSs. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed study design and quality, and extracted data. We contacted study authors for additional information. We collected information on adverse effects from included articles, and contacted authors. MAIN RESULTS: We found no RCTs or quasi-RCTs, and therefore could not establish the effect of ephedrine on MG, NMG and CMSs. We describe the results of 53 non-randomised studies narratively in the Discussion section, including observations of endurance, muscle strength and quality of life. Effects may differ depending on the type of myasthenia. Thirty-seven studies were in participants with CMS, five in participants with MG, and in 11 the precise form of myasthenia was unknown. We found no studies for NMG. Reported adverse effects included tachycardia, sleep disturbances, nervousness, and withdrawal symptoms. AUTHORS' CONCLUSIONS: There was no evidence available from RCTs or quasi-RCTs, but some observations from non-randomised studies are available. There is a need for more evidence from suitable forms of prospective RCTs, such as series of n-of-one RCTs, that use appropriate and validated outcome measures.

Update on juvenile myasthenia gravis.

PURPOSE OF REVIEW: Juvenile myasthenia gravis is a relatively rare autoimmune neuromuscular disorder. The pathophysiology of juvenile myasthenia gravis is similar to that of adult myasthenia gravis, though there remain important differences regarding presentation and therapeutic options. We review the pathophysiology, clinical presentation, and treatment options for juvenile myasthenia gravis. RECENT FINDINGS: Randomized clinical studies of myasthenia gravis have been carried out primarily in adult populations. As juvenile myasthenia gravis is rare, it has been difficult to collect prospective randomized controlled data to evaluate treatment outcomes and efficacy. A recent retrospective series suggests that, as in adult myasthenia gravis, thymectomy is a viable therapeutic option for selected cases of generalized juvenile myasthenia gravis. This is corroborated by the clinical experience of the authors in a referral center with a cohort of patients affected by juvenile myasthenia gravis over a number of years. SUMMARY: Recent studies illustrate that some, but not all, adult research on myasthenia gravis is applicable to children and adolescents with juvenile myasthenia gravis. Adult research can inform pediatric studies, but should not be regarded as a substitute for dedicated research in those populations.

Congenital myasthenic syndromes and transient myasthenia gravis.

Hypotonia in the neonatal period and early infancy is a common clinical finding. It can be caused by various heterogeneous disorders of different origin which might lead to diagnostic difficulties. Disorders of the neuromuscular junction, such as congenital myasthenic syndromes and neonatal transient myasthenia gravis are among the aetiologies. We report on a case of congenital myasthenia caused by mutation in the long cytoplasmic loop of the epsilon subunit of the acetylcholine receptor and a neonate of a myasthenic mother diagnosed with transient myasthenia gravis.

Prenatal immunomodulation treatment in neonatal myasthenia gravis.

Neonatal mysthenia gravis (NMG) is a rare cause of arthrogryposis multiplex congenita (AMC) due to diaplacental transfer of maternal acetylcholine receptors (AChR) antibodies. 2 cases of severe NMG complicated by chronic lung disease and pulmonary arterial hypertension are reported. With respect to the severe course of the index patient, prenatal diagnosis and immunomodulation treatment were offered during the 2nd pregnancy. The combination of prenatal immunoadsorption (IA) therapy, administration of intravenous immunoglobulin (IVIG) and prednisolone failed. Failure may be partly explained by immaturity of the infant. However, considering the successful treatment of fetal/neonatal alloimmune thrombocytopenia (AIT) reported in literature, a treatment approach with IVIG doses up to 1-2 g/kg per week plus prednisone/prednisolone at a higher dose up to 1 mg/kg/d might be more effective.

Transient neonatal myasthenia gravis in a baby born to a mother with new-onset anti-MuSK-mediated myasthenia gravis.

We describe a 30-year-old pregnant woman with undiagnosed weakness who delivered a severely weak neonate. Subsequent workup of the mother revealed myasthenia gravis with muscle-specific kinase antibodies. The infant responded to intravenous immunoglobulin and symptoms normalized. He was presumed to have an anti-muscle-specific kinase-mediated transient neonatal myasthenia gravis.

Seronegative neonatal myasthenia gravis in one of the twins.

Neonatal myasthenia gravis has been described as a transient condition affecting only a small percent of neonates. We report a twin gestation in a seronegative mother with myasthenia gravis, in which only one twin was affected.

The natural history and ophthalmic involvement in childhood myasthenia gravis at the hospital for sick children.

OBJECTIVE: To characterize signs, symptoms, and the natural history of myasthenic syndromes in pediatric patients. DESIGN: Retrospective noncomparative case series. PARTICIPANTS: Thirty-four patients with a diagnosis of myasthenia were identified from either the hospital's or treating physician's database. METHODS: Retrospective chart review, clinical examination, and telephone interview. MAIN OUTCOME MEASURES: Information pertaining to the ophthalmologic and neurologic examination, diagnostic interventions, and treatment was noted. Patients with active disease, attending during the study period, were examined at their outpatient visits. Those who no longer attended the hospital were contacted by means of a telephone interview to complete their follow-up. RESULTS: Thirty-four children were found to have myasthenia. Two had transient neonatal myasthenia, which resolved quickly. Seven (20.6%) patients had congenital myasthenic syndromes (CMS) and 25 (73.5%, 19 females) were affected with autoimmune myasthenia gravis (AMG). In those patients with severe CMS, three showed signs of generalized weakness, including failure to thrive, frequent apneas, and aspirations. In four patients with mild CMS, eye signs were relatively more prominent. In all patients with CMS, strabismus, ophthalmoplegia, and ptosis were the main ophthalmologic signs and remained relatively constant. Fourteen (56%) patients with AMG had ocular signs and symptoms, and five of them progressed to systemic involvement in 7.8 months on average (range, 1-23). The remaining nine patients with ocular AMG had either strabismus or ptosis and were treated with pyridostigmine (nine patients) and prednisone (two patients). Patients with ocular AMG were seen at 78 months on average, those with systemic AMG at 85.6 months. Systemic AMG was seen in 16 patients. No thymomas were found in 14 patients who underwent thymectomy. Of the 25 patients with AMG, 8 are still being treated, 8 are in remission for an average of 65.2 months and are asymptomatic, 4 patients are receiving long-term immunosuppressants (1 has likely sustained permanent damage to her extraocular muscles with complete ophthalmoplegia and ptosis), and 4 have been lost to follow-up. Finally, one patient died after aspiration because of bulbar weakness. CONCLUSIONS: Patients with CMS varied in the degree of severity. Apneic attacks, aspiration, and failure to thrive may obscure the diagnosis. Compared with AMG, their ophthalmologic signs and symptoms were usually permanent. Visual signs and symptoms were usually prominent in those patients with active AMG, but those in remission were asymptomatic. More than half of the patients with juvenile AMG had ocular symptoms. Generalization occurred in a minority in an average of 7.8 months. Patients entered remission after approximately 2 years of treatment and were visually asymptomatic. This study suggests that long-term permanent damage to the extraocular muscles as a result of juvenile AMG is rare. Myasthenia gravis is a life-threatening disease as evidenced by the death of one of our patients. Many of these patients are first seen by the ophthalmologist who can aid the diagnosis, screen for amblyopia, and monitor the patient's response to therapy.