ПРИЧИНЫ, ФАКТОРЫ РИСКА, КЛИНИЧЕСКИЕ ПРЕДИКТОРЫ РАЗВИТИЯ КРИЗОВ У БОЛЬНЫХ МИАСТЕНИЕЙ

We analyzed the main causes of myasthenic crisis in 54 patients with myasthenia gravis. It is shown that myasthenic crisis can appear at any age both in men and women with the same incidence in old age patients and with higher prevalence in woman in young age patients (5:1). The crisis can appear acutely, subacutely and as the fi rst manifestation of the disease. Myasthenic crisis in the debut of myasthenia gravis was revealed in 5 cases of disease with late onset (age 58- 85 years) and was misdiagnosed in all the cases. Crisis in patients with myasthenia gravis occurred frequently within the fi rst year after disease onset and was associated with late diagnosis and inadequate treatment. Occurrence of myasthenic crisis after the fi rst year of disease was signifi cantly more often associated with cessation of corticosteroid therapy or excessive reduction of its dose. Respiratory infection was the most common primary provoker of crisis in 1/3 patients. There are several important predictors of severe myasthenia gravis with myasthenic crisis: craniobulbar clinical pattern, low sensitiveness to anti-cholinesterase drugs, combination of myasthenia and thymoma, ineffective thymectomy. Detecting in serum the antibodies to specifi c tyrosine kinase muscle and marked decrease of compound motor action potential (CMAP) to a single supramaximal stimulus in clinically affected muscles are unfavorable prognostic factor. Titer of antibodies to acetylcholine receptors and degree of the decrement of CMAP to low-frequency stimulation in repetitive stimulation had no predictive value in the development of myasthenic crisis.