Studies in myasthenia gravis

https://acsjournals.onlinelibrary.wiley.com/doi/pdf/10.1002/1097-0142%28196509%2918%3A9%3C1131%3A%3AAID-CNCR2820180914%3E3.0.CO%3B2-F

Pathology and clinical behavior of thymomas. a survey of 51 cases.

The thymus has been an enigmatic organ for centuries. Some of the ancient Greeks considered it to be the seat of the soul. Galen, on the other hand, thought that it acted as a cushion to protect the great vessels from the bony sternum. Since then, contentions and controversies have involved most of the questions regarding its embryology, anatomy, physiology, and pathology. Indeed, \" has it yet fallen to the lot of any writer upon the thymus to write the truth and be believed ? \" (Beard, 1902).

https://www.bmj.com/content/bmj/2/5355/459.full.pdf

Role of the thymus in immunity.

For many years, myasthenia gravis was regarded primarily as a disorder of neuromuscular function; most research centered upon electrophysiological and pharmacological techniques. Since 1960, however, the concept tha t myasthenia may be an “autoimmune” disease has received much attention. The evidence for this rests primarily upon two recent findings: the presence of serological abnormalities, first demonstrated by Strauss, and coworkers‘ and evidence that the thymus plays a role in the development of immunological ~apac i ty . ‘ .~ Both subjects are discussed elsewhere in this volume. We have reviewed the series of patients a t Columbia-Presbyterian Medical Center to evaluate clinical features which might suggest immunological abnormality. I t is difficult to establish the kind of evidence which would support the concept of autoimmune pathogenesis, because there is no pathognomonic test to establish any disease in this category. We have tried to determine whether myasthenia occurs frequently in association with other diseases regarded as autoimmune, whether laboratory abnormalities of the kind seen in “autoimmune diseases” occur in myasthenia, whether therapy directed to alternation of immunological function is beneficial, and whether thymectomy is effective. Since no disease has been proven to have an autoimmune pathogenesis, comparison of myasthenia with other diseases may not be valid, and this deficiency is kept in mind.

Myasthenia as an autoimmune disease: clinical aspects*

Patients with myasthenia gravis (MG) may develop heart disease. Our data on 108 MG patients were examined to assess the type and frequency of this. 17 of 108 patients (16%) showed signs of heart disease which could be regarded as MG-related. 11 of these, of whom 5 died suddenly, had clinical symptoms, mainly arrhythmias. Signs of heart disease were most frequent in thymoma patients (5 of 10), and all 3 microscopically examined hearts from these patients showed a focal myocarditis. 44 spinal muscular atrophy patients serving as controls showed a 16% frequency of signs of heart disease of unknown etiology. However, only 1 of 44 spinal muscular atrophy patients (2%) had clinical symptoms as compared to 11 of 108 MG patients (10%). Together with the characteristic focal nature of the myocarditis and the microscopic similarities between lesions of heart and skeletal muscle, this indicates that the heart disease is specifically related to MG.

Mendelow H

Papers

Studies in myasthenia gravis: cardiac and associated pathology.