Ocular myasthenia gravis (OMG) is characterized by symptoms confined to the extraocular muscles and progresses to generalized myasthenia gravis (GMG) in approximately half of patients, most commonly within two years of onset. Several predictors of generalization have been identified, including anti-acetylcholine receptor (AChR) antibody seropositivity, abnormal repetitive nerve stimulation (RNS) findings, older age at onset, thymoma, and greater disease severity. However, the prognostic significance of early relapse frequency in OMG remains poorly defined. We report a patient with OMG marked by early, recurrent relapses who subsequently progressed to GMG. A 69-year-old male presented with a three-day history of diplopia. Neurological examination revealed no bulbar, respiratory, or limb weakness. Laboratory testing showed elevated anti-AChR antibody levels (12 nmol/L), and RNS demonstrated a significant decremental response in the trapezius and nasalis muscles. Imaging studies revealed no evidence of thymoma. Based on ocular symptoms and supportive serological and electrophysiological findings, a diagnosis of OMG was established. High-dose intravenous methylprednisolone led to complete resolution of symptoms. Despite maintenance therapy with low-dose oral prednisolone, the patient experienced relapses of diplopia and ptosis at two and four months after onset, each requiring additional courses of high-dose intravenous methylprednisolone. During this period, no generalized muscle weakness was observed, and anti-AChR antibody titers remained stable. Seven months after onset, the patient developed dyspnea and bulbar symptoms, accompanied by a marked increase in anti-AChR antibody levels (81 nmol/L). Clinical deterioration, abnormal respiratory parameters, and a positive edrophonium test confirmed progression to GMG. Plasma exchange resulted in rapid clinical improvement, and symptoms were subsequently controlled with prednisolone and tacrolimus. In this case, relapses at months two and four occurred in the absence of generalized weakness and preceded generalization at month seven, suggesting that early, frequent relapses may represent a potential predictor of generalization in OMG. These findings underscore the potential importance of relapse frequency as a clinical marker and emphasize the need for treatment strategies in OMG aimed not only at symptom control but also at preventing generalization.
Terai et al. (Fri,) studied this question.