DOUBLE SERO-NEGATIVE MYASTHENIA GRAVIS ASSOCIATED WITH THYMIC HYPERPLASIA AND AUTOIMMUNE THYROIDITIS IN A YOUNG PATIENT

Myasthenia gravis is an autoimmune disorder affecting the postsynaptic neuromuscular junction. Clinically it evolves with fluctuating muscle weakness. In 13-22% of the reported cases, another autoimmune disorder is associated. We report the case of a 21 years old woman presenting at 4 months after delivrence, global muscle weakness, dysphonia, dysartria and dysphagia. Biological tests reveal: AchR antibodies and anti-MUSK antibodies – negative, TSH 4,68 μIU/ml (normal range: 0,4-4 μIU/ml), FT4 0,785 ng/dl (normal range: 0,89-1,76 ng/dl), anti thyroglobulin antibodies 183,01 IU/mL (normal range: <4,11 IU/mL), Chest CT – thymic hyperplasia and EMG – decremental response at repetitive stimulation. It is established the diagnosis: myasthenia gravis Osserman stage IIb. After treatment with acetylcholine esterase inhibitors and corticosteroids the patient`s symptomathology has improved.