Severe Preeclampsia in the Setting of Myasthenia Gravis

Intravenous magnesium sulfate inducing acute respiratory failure in a patient with myasthenia gravis

A woman in her 90s with a background of myasthenia gravis and atrial fibrillation presented to hospital following a fall. While in the emergency department it was noted that she was in atrial fibrillation with a fast-ventricular response and as part of her management was given intravenous magnesium. Following this she developed acute respiratory failure and required intubation and ventilation. The patient recovered quickly and was extubated in the intensive care unit the next day. On subsequent days, the patient received two further doses of intravenous magnesium before the link was identified. On both of these occasions she again developed respiratory failure which were managed with non-invasive ventilation. This case highlights the importance of all members of the team being aware of the drugs that can induce a myasthenic crisis. It also stimulates further research into the development of a guide of how to safely treat symptomatic hypomagnesaemia in patients with myasthenia gravis.

Neurocritical Care of the Pregnant Patient

Purpose of review

To summarize recent changes in management and emerging therapies for pregnant neurocritical care patients.

Recent findings

Diagnostic and treatment options for managing neurologic emergencies in pregnant patients have expanded with both greater understanding of the effects of imaging modalities and medications on pregnancy and application of standard treatments for non-pregnant patients to pregnant populations. Specifically, this includes cerebrovascular diseases (pregnancy-associated ischemic stroke, pregnancy-associated intracerebral hemorrhage, cerebral venous sinus thrombosis), post-maternal cardiac arrest care, seizures and status epilepticus, myasthenia gravis, and fetal somatic support in maternal death by neurologic criteria.

Summary

With the exception of direct abdominal computed tomography (CT), most imaging studies are reasonably safe in pregnancy. When emergent imaging is needed to prevent maternal morbidity or mortality, any CT sequence with or without contrast is appropriate to pursue. Though new safety data on antiplatelets, antihypertensives, thrombolytics, and antiepileptic drugs have increased options for disease management in pregnancy, unfractionated and low-molecular weight heparin remain the safest options for anticoagulation. Early studies on hypothermia, ketamine, and immunomodulating therapies in pregnancy are promising. In myasthenia gravis, new data on adjunct devices may allow more patients to undergo safe vaginal delivery, avoiding cesarean section and the associated risk of crisis. When difficult decisions regarding preterm delivery arise, recent outcome studies can help inform discussion. Lastly, when the feared complication of maternal death by neurologic criteria occurs, fetal somatic support may help to save at least one life.

Italian recommendations for the diagnosis and treatment of myasthenia gravis

Myasthenia gravis is a well-treatable disease, in which a prompt diagnosis and an adequate management can achieve satisfactory control of symptoms in the great majority of patients. Improved knowledge of the disease pathogenesis has led to recognition of patient subgroups, according to associated antibodies, age at onset and thymus pathology, and to a more personalized treatment. When myasthenia gravis is suspected on clinical grounds, diagnostic confirmation relies mainly on the detection of specific antibodies. Neurophysiological studies and, to a lesser extent, clinical response to cholinesterase inhibitors support the diagnosis in seronegative patients. In these cases, the differentiation from congenital myasthenia can be challenging. Treatment planning must consider weakness extension and severity, disease subtype, thymus pathology, together with patient characteristics and comorbidities. Since most subjects with myasthenia gravis require long-term immunosuppressive therapy, surveillance of expected and potential adverse events is critical. For patients refractory to conventional immunosuppression, the use of biologic agents is highly promising. These recommendations are addressed to non-experts on neuromuscular transmission disorders. The diagnostic procedures and therapeutic approaches hereafter described are largely accessible in Italy.

Myasthenia Gravis and Crisis: Evaluation and Management in the Emergency Department

BACKGROUND

Myasthenia gravis (MG) is an uncommon autoimmune disorder affecting the neuromuscular junction and manifesting as muscle weakness. A multitude of stressors can exacerbate MG. When symptoms are exacerbated, muscle weakness can be severe enough to result in respiratory failure, a condition known as myasthenic crisis (MC).

OBJECTIVE

This review discusses risk factors, diagnosis, management, and iatrogenic avoidance of MC.

DISCUSSION

MC can affect any age, ethnicity, or sex and can be precipitated with any stressor, infection being the most common. MC is a clinical diagnosis defined by respiratory failure caused by exacerbation of MG. Muscle weakness can involve any voluntary muscle. MC can be differentiated from other neuromuscular junction diseases by the presence of normal reflexes, normal sensation, lack of autonomic symptoms, lack of fasciculations, and worsening weakness with repetitive motion. Treatment should target the inciting event and airway support. All acetylcholinesterase inhibitors should be avoided in crisis, including edrophonium testing and corticosteroids initially. Respiratory support can begin with noninvasive positive-pressure ventilation, as this has been successful even in patients with bulbar weakness. If intubation is necessary, consider avoiding paralytics or use a reduced dose of nondepolarizing agents.

CONCLUSIONS

MC should be in the differential of any patient with muscular weakness and respiratory compromise. Emergency department management of MC should focus on ruling out infection and respiratory support. Strong consideration should be given to beginning with noninvasive positive-pressure ventilation for ventilatory support. Corticosteroids, depolarizing paralytics, and acetylcholinesterase inhibitors should be avoided in patients with MC in the emergency department.