Miastenia Gravis de Predominio Ocular

Abstract

Myasthenia gravis is a neuromuscular disorder, autoimmune mediated by antibodies (Ac) decreasing the number of acetylcholine receptors at neuromuscular junctions leading cause regarded as disturbances thymus. Globally the annual incidence is 1-5 / 10,000 inhabitants, is predominant in women 21-39 and men aged 50 – 69. In Ecuador Are null epidemiological studies. It is characterized by progressive muscle weakness and fatigue that starts in eye muscles and if in 3 years is not associated with extraocular symptoms, 90% were not widespread. Its main classification is ocular and generalized MG triggers that can reach a myasthenic crisis with 4.4% mortality. The treatment begins with anticholinesterase short term, it continues with long-term corticosteroid (best alternative) and in a few cases are associated immunomodulators; while in severe forms plasmapheresis and IV Ig is used, in MG with thymoma is used thymectomy. The current forecast is promising.

The case of a male patient of 20 years with no history who goes by more left eyelid ptosis and double vision, general weakness of 48 hours of evolution is presented. Physical examination is ptosis, bilateral horizontal nystagmus and paresis of cranial nerves IV and VI. We use neostigmine test: positive, mediastinal TAC without disturbances thymus, Ac ANA, ANCA and LE cells: negative. It is not used the repetitive stimulation test or single fiber electromyography due to lack of adequate equipment nor the AChR antibodies that were not managed are not made. It starts corticosteroid therapy with prednisone 20mg c / 8 hours evaluated at 2 weeks noticing relative remission. At 3 months comes back and inadvertently reduces the dose to 40mg / day for 1 month, further beneficial effect is maintained and no involvement of other muscle groups.

It is concluded that the characteristic symptoms of ocular MG comprises ptosis, diplopia and nystagmus and established with specified clinical tests, and pharmacological, serological and electrophysiological analysis according to their sensitivity contribute to the diagnosis of ocular MG predominantly available in our environment and finally similar tables should be well differentiated.