A 48-year-old female with a history of undifferentiated CNS demyelination concerning for multiple sclerosis was brought to the emergency department by her spouse for a three-day history of irregular respirations. During inhalation, she exhibited frequent and irregular diaphragmatic contractions but no periods of apnea were noted. Her ability to phonate, swallow, manage secretions, and cough remained unchanged. Vital signs, blood count, metabolic panel, and arterial blood gas results were normal. Her neurological exam was pertinent for acute worsening of mild baseline chronic right hemiparesis and bilateral ataxia. 

Within several hours of admission, she decompensated and progressed to acute hypoxic and hypercapnic respiratory failure with the development of stridor. Flexible video laryngoscopy was performed which revealed   right greater than left vocal fold dysfunction, and the patient was emergently intubated. Contrasted magnetic resonance imaging of the brain demonstrated T2/FLAIR lesions in the pons, medulla, and right basal ganglia, with gadolinium enhancement of the right medulla indicating areas of active demyelination. The patient was started on high-dose intravenous solumedrol and plasmapheresis, leading to gradual improvement in her right-sided weakness. She remains intubated pending clinical resolution of her respiratory failure.