Rapid weaning from mechanical ventilator in acute cervical cord multiple sclerosis lesion after steroids

Multiple Sclerosis and related disorders

Multiple Sclerosis (MS) is a common neuroinflammatory disorder which is associated with disabling clinical consequences. The MS disease process may involve neural centers implicated in the control of breathing, leading to ventilatory disturbances during both wakefulness and sleep. In this chapter, a brief overview of MS disease mechanisms and clinical sequelae including sleep disorders is provided. The chapter then focuses on obstructive sleep apnea-hypopnea (OSAH) which is the most prevalent respiratory control abnormality encountered in ambulatory MS patients. The diagnosis, prevalence, and clinical consequences as well as data on effects of OSAH treatment in MS patients are discussed, including the impact on the disabling symptom of fatigue and other clinical sequelae. We also review pathophysiologic mechanisms contributing to OSAH in MS, and in turn mechanisms by which OSAH may impact on the MS disease process, resulting in a bidirectional relationship between these two conditions. We then discuss central sleep apnea, other respiratory control disturbances, and the pathogenesis and management of respiratory muscle weakness and chronic hypoventilation in MS. We also provide a brief overview of Neuromyelitis Optica Spectrum Disorders and review current data on respiratory control disturbances and sleep-disordered breathing in that condition.

The neurology of acutely failing respiratory mechanics

Forces involved in breathing-which effectively pull in air-are the diaphragmatic, intercostal, spine, and neck muscles. Equally important is the bulbar musculature maintaining the architecture of a patent airway conduit and abdominal wall and internal intercostal muscles providing cough. Acute injury along a neural trajectory from brainstem to muscle will impair the coordinated interaction between these muscle groups. Acutely failing respiratory mechanics can be caused by central and peripheral lesions. In central lesions, the key lesion is in the nucleus ambiguus innervating the dilator muscles of the soft palate, pharynx, and larynx, but abnormal respiratory mechanics rarely coincide with abnormalities of the respiratory pattern generator. In peripheral lesions, diaphragmatic weakness is a main element, but in many neuromuscular disorders mechanical upper airway obstruction from oropharyngeal weakness contributes equally to an increased respiratory load. The neurology of breathing involves changes in respiratory drive, rhythm, mechanics, and dynamics. This review focuses on the fundamentals of abnormal respiratory mechanics in acute neurologic conditions, bedside judgment, interpretation of additional laboratory tests, and initial stabilization, with practical solutions provided. Many of these respiratory signs are relevant to neurologists, who in acute situations may see these patients first. Ann Neurol 2017;81:485-494.

Respiratory dysfunction in multiple sclerosis

Respiratory dysfunction frequently occurs in patients with advanced multiple sclerosis (MS), and may manifest as acute or chronic respiratory failure, disordered control of breathing, respiratory muscle weakness, sleep disordered breathing, or neurogenic pulmonary edema. The underlying pathophysiology is related to demyelinating plaques involving the brain stem or spinal cord. Respiratory complications such as aspiration, lung infections and respiratory failure are typically seen in patients with long-standing MS. Acute respiratory failure is uncommon and due to newly appearing demyelinating plaques extensively involving areas of the brain stem or spinal cord. Early recognition of MS patients at risk for respiratory complications allows for the timely implementation of care and measures to decrease disease associated morbidity and mortality.