Poussée myasthénique inaugurale en réanimation. Comment la reconnaître et la traiter ?

Myasthenia is an autoimmune disorder of the neuromuscular junction characterized by a muscular weakness and fatigability with a variable intensity and extension. Its evolution is characterized by acute exacerbation; swallowing impairment and respiratory failure are present in severe forms that are called “myasthenic crisis” when mechanical ventilation is required. This major expression of the disease can be inaugural. In that case, an important diagnostic orientation is mostly given by a rigorous clinical analysis, which allows to recognize the neuromuscular origin of the respiratory infringement and the particular characteristics of the other motors deficits almost constantly associated. An immediate additional argument can be supplied by a transient but strong clinical improvement after injection of an acetylcholine esterase blocker. But if the suspicion of myasthenia is important sufficient results of electromyographic examination and antibodies positivity against achetylcholine receptors or anti-Musk should not be waiting to start supportive or specific treatments, including immunomodulators, plasma exchanges, intravenous immunoglobulins and corticoids. Myasthenic crises, even observed with an increasing frequency in aged patients, have a relatively good prognosis (mortality rate 5%) conditioned by an early and appropriate management.