CD8A and Fatigable weakness: In contrast, electromyography predominantly revealed subacute myogenic findings, with one patient exhibiting a neurogenic pattern. Muscle biopsies demonstrated CD8+-predominant inflammatory infiltration. The diagnosis of coexisting myasthenia was supported based on fluctuating symptoms and ventilator requirements, such as tidal volume and inspiratory pressure, as well as pyridostigmine responsiveness, rather than serologic findings.