STROKE AND MYASTHENIA GRAVIS LEAD TO CRISIS IN THE ELDERLY

Abstract

SESSION TITLE: Tuesday Medical Student/Resident Case Report Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: 10/22/2019 01:00 PM - 02:00 PM INTRODUCTION: Myasthenia gravis (MG) is frequently underdiagnosed especially in the elderly population with comorbid illness [1]. Late-onset MG is defined as onset after the age of 50 [2]. MG is especially difficult to identify in patients with recent stroke given overlapping signs and symptoms. We present here a case of late-onset MG preceded by an acute stroke that pursued a rapid downhill course leading to myasthenic crisis and acute respiratory failure. CASE PRESENTATION: The patient was a 75 year old male who presented for inpatient rehabilitation after an acute medullary stroke. During rehab, the patient developed new onset diplopia and bilateral ptosis which was initially thought to be due to progression of his stroke. His symptoms continued to worsen, however, and infection, thyroid dysfunction, electrolyte abnormalities, and stroke progression was ruled out by appropriate laboratory and radiographic studies. The patient was subsequently found to have positive AChR antibodies with a positive pyridostigmine test confirming the diagnosis of MG. A CT thorax was negative for thymoma. Despite aggressive treatment with IVIG and systemic steroids, the patient’s disease progressed to the development of a myasthenic crisis. Even with the initiation of plasmapheresis the patient developed acute hypercapneic respiratory failure necessitating endotracheal intubation and mechanical ventilation. The patient failed to respond to therapy and was ultimately withdrawn from life support at the request of the DPOA. DISCUSSION: We present an unusual scenario of late onset MG confounded by the presence of an acute medullary stroke. Acute stroke and MG rarely coincide in the same patient; in fact only a single case is reported that had both conditions concurrently [3]. To our knowledge, this is the first case report of a rare presentation of combined acute stroke and MG progressing to acute myasthenic crisis. With our aging population, prevalence of late-onset MG is on the rise [2]. Although difficult due to physiological changes that occur with aging, prompt diagnosis is crucial especially in the elderly population. Delayed diagnosis can be catastrophic as seen in our patient with abrupt decline. We postulate that the rapid progression of the patient’s respiratory failure and inability to successfully liberate from mechanical ventilation was due to the simultaneous insults to the medullary respiratory center and respiratory musculature from the two neurologic disorders. CONCLUSIONS: MG should remain in the differential diagnosis especially in elderly patients presenting with sudden onset of ocular symptoms even in post stroke patients. Patients can have rapid progression to myasthenia crisis when the respiratory system is already compromised by medullary stroke. Reference #1: Aarli JA. Myasthenia gravis in the elderly: is it different? Ann N Y Acad Sci 2008;1132:238-43. Reference #2: Aarli JA. Late-onset myasthenia gravis: a changing scene. Arch Neurol. 1999;56:25–27. Reference #3: Kim SJ, Park GY, Choi YM, Sohn DG, Kang SR, Im S. Bulbar Myasthenia Gravis Superimposed in a Medullary Infarction Diagnosed by a Fiberoptic Endoscopic Evaluation of Swallowing With Simultaneous Tensilon Application. Ann Rehabil Med. 2017;41(6):1082-1087. DISCLOSURES: No relevant relationships by Nemer Dabage-Forzoli, source=Web Response No relevant relationships by Sana Khan, source=Web Response No relevant relationships by Nick Meyerkord, source=Web Response No relevant relationships by Charles Schroeder, source=Web Response No relevant relationships by Yunna Sinskey, source=Web Response No relevant relationships by Shashank Varakantam, source=Web Response