Myasthenia Gravis Mimicking Acute Cerebrovascular Events

Abstract

Background and Objective: Myasthenia gravis (MG) is an immune-mediated disorder that can sometimes present acutely with a focal neurological deficit and thus mimic a cerebrovascular event. The objective of this study was to describe the clinical characteristics in a large cohort of patients who were initially misdiagnosed with an acute vascular event and later diagnosed with MG.
 Methods: This is a retrospective chart review of patients who were initially diagnosed with an acute cerebrovascular event but subsequently found to have MG. The chart review was done for the period from January 2013 to December 2017, and patients with at least one-year follow-up included. Data are reported as means ± SEM, and the results reported using prevalence rates.
 Results: Twenty-one patients met our inclusion criteria. Among them, 13 (61.9%) were female with a mean age of 56.7 ± 4.07 years. Ten were MGFA class 3a; seven were MGFA class 2b, 3 were MGFA 3b. Eighteen patients were acetylcholine receptor antibody positive; one was MuSK positive, and the rest two seronegative. Slurred speech (8 patients, 38.1%) was the most common symptom that resulted in misdiagnosis, followed by hemibody weakness (7 patients, 33.3%) and dysphagia (3, 14.3%). Smoking (12, 57.1%) and hypertension (11, 52.4%) were common risk factors for cerebrovascular disease. Small vessel disease was suspected the most common etiology (15, 71.4%) of the vascular event. Ten patients had received thrombolytic therapy, and 16 patients were on antiplatelets. 4 patients who presented recurrent symptoms placed on anticoagulants. 
 Conclusion: Acute presentation of bulbar symptoms and hemibody weakness resulted in the misdiagnosis of MG.

Analysis of events from sudden isolated dysarthria to diagnosis of myasthenic crisis: myasthenia gravis mimicking acute lacunar stroke—a case report

“…Due to its broad spectrum of manifestations diagnosis can be difficult with such diverse manifestations, and clinical suspicion is paramount. Ptosis is the leading indicator of MG. With age-related changes in eyelid appearance making it more noticeable in younger individuals, diagnosing it in older individuals may be challenging due to overlapping visual symptoms with age-related ocular conditions such as macular degeneration or cataracts [ 9 ]. In a Southern China report, 82.0% of MG-diagnosed individuals exhibited only ocular symptoms at onset, emphasizing the prevalence of ocular manifestations of MG [ 10 ].…”

“…Another retrospective review of twenty-one cases of elderly patients initially treated as an acute cerebrovascular event for stroke-like symptoms that were subsequently diagnosed with new-onset MG. Among this group, slurred speech (8 among 21 cases, 38.1%) was the most common symptom that resulted in misdiagnosis of stroke in the first place [ 9 ]. It is crucial to remember that although MG commonly occurs in younger populations, it can also manifest later in life.…”