Factors of stroke misdiagnosis at the onset of myastenia gravis

BACKGROUND: Myasthenia gravis is a rare autoimmune disease,which is difficult to diagnose mainly in the initial stages, when there are single symptoms of the disease or an atypical course. Diagnostic errors are associated with the fact that myasthenia gravis and other diseases of the nervous system have similar symptoms. The most common misdiagnosis in the onset of myasthenia gravis is a stroke. However, the reasons for a false diagnosis remain unspecified and poorly understood. AIM: To determine the factors leading to misdiagnosis of a stroke in the onset of myasthenia gravis. MATERIALS AND METHODS: 133 patients diagnosed with myasthenia gravis were divided into two groups. Patients with misdiagnosed stroke at the onset of myasthenia gravis formed the first group, the rest of the patients – the second group. A comparative assessment was performed according to the age of myasthenia onset, the clinical variant of the onset, primary symptoms, the duration of diagnosis, and the severity of the disease at the time of the correct diagnosis, with the percentage of misdiagnosis calculation. RESULTS: Stroke as misdiagnosis was established more often than others (in 23% of all cases and in 44% of incorrect diagnoses). In the 1st group, complaints of dysarthria and dysphagia were significantly higher, myasthenia gravis began acutely more often, the age of myasthenia onset in patients of the 1st group was statistically higher than in the 2nd. There was no difference between the groups in terms of diagnosis duration, the disease severity, and the history of previous stroke. CONCLUSIONS: Factors leading to stroke misdiagnosis at the onset of myasthenia are advanced age and acute onset with bulbar disorders.