Myasthenia Gravis Associated with Diabetes about an Observation in Dakar, Senegal (West Africa) and Review of the Literature

Myasthenia gravis is a rare disease with very few confirmed cases described in the African setting. We report the case of a 41-year-old woman with a history of type 2 diabetes, high blood pressure (well monitored), and migraine with aura. She was received at the outpatient neurology consultation for a left ptosis, diplopia, chewing and walking difficulties. She reported abnormal and fluctuating muscle fatigability at effort, responsible for several falls. These symptoms were marked at evening, and were evolving since four years before her consultation in our center. She also reported a history of palpitations, exertional dyspnea, dysphonia, dysphagia and 20 kg weight loss. Neurological examination found a horizontal diplopia, a left ptosis and abnormal weakness at dynamic eyes and limb muscles testing. Otherwise the remaining neurological examination was unremarkable. Repetitive nerve stimulation found a significant compound muscle action potentials decrement. The immunological tests showed a very high level of antibodies to acetylcholine receptors (anti-AChR) at 1220.00 nmol/l (normal value <0.40 nmol/l). Thyroid tests and the remaining biological tests were normal. Thorax CT-scan was normal, with no thymoma. Considering these results, the diagnosis of anti-AchR myasthenia gravis was established. She was started on pyridostigmine 60 mg four times daily associated to her previous hypertension and diabetes therapy. Outcome after five months of treatment was marked by a complete recovery of muscle weakness and weight. Myasthenia gravis is a rare disease, frequently leading to a misdiagnosis. His association with diabetes is well established. It is worth to think about it when dealing with patients presenting fatigue with a history of diabetes.