Coexistance of Probable Neurosarcoidosis and Generalized Myasthenia Gravis: Case Report

Objective NA. Background Sarcoidosis is an immune mediated disorder characterized by the formation of non-necrotizing granulomas in multiple organs. The broad range of manifestations of sarcoidosis in the nervous system includes cranial neuropathy, meningitis or myelopathy. Generalized Myasthenia Gravis is a neuromuscular disorder characterized by the formation of antibodies against the acetylcholine receptor, and typically presents with muscle weakness and fatigue. Association of Myasthenia Gravis and Neurosarcoidosis is infrequent. Design/Methods NA. Results Case report: A thirty-five year old woman, natural from Senegal was admitted to the hospital with a two month history of left peripheral facial nerve palsy, progressive dysphonia and dysphagia, associated with fever, headache and asthenia. Examination revealed, left facial numbness and weakness (V and VII nerve) and right vocal cord paresis (X nerve). Chest ray showed bilateral hilar lymphadenopathy and cranial MRI revealed enhancement of both Meckel cavum, bilateral trigeminal nerves and canalicular segment of the left facial nerve. CSF examination detected elevated protein and lymphocytic pleocytosis. For further study a PET/TC was done which revealed supradiaphragmatic and infradiaphragmatic hypermetabolic adenopathies. Biopsy of an adenopathy was performed objecting non-caseating granulomas consistent with the diagnosis of probable neurosarcoidosis. Moreover, the patient explained weakness and muscle fatigue since she was 18 years old, which was observed at proximal limb muscles. Acetylcholine receptor antibodies were detected and electromyographic study showed a decremental response to repeated nerve stimulation. Conclusions It is well known that autoimmune disorders may coexist in some patients. Neurosarcoidosis and Myasthenia Gravis are two rare diseases with different pathogenesis. Although their coexistance could be coincidental it may also suggest immunologic mechanisms triggering the occurrence of these diagnoses together.