Clinical and Electrophysiological Evaluation of Patients with Thymic Pathology in Terms of Myasthenia Gravis
Beyza Arslan1, Pınar Kahraman2, Kayıhan Uluc2
1Marmara University, School of Medicine, Department of Neurology, 2Acıbadem Ataşehir Hospital, Department of Neurology
Objective:
Myasthenia Gravis (MG) is an autoimmune disease known to be often associated with thymic pathologies. This study aimed to evaluate the clinical, serological and electrophysiological data of patients with thymic pathology in terms of possible accompanying MG.
Background:
MG is an autoimmune disease known to be often associated with thymic pathologies. This study aimed to evaluate the clinical, serological and electrophysiological data of patients with thymic pathology in terms of possible accompanying MG.
Design/Methods:
In our study, patients who were consulted to the neurology unit by the thoracic surgery unit in 2021-2022 for possible accompanying MG due to diagnoses of thymic hyperplasia or thymoma were evaluated. Clinical findings of the patients, acetylcholine receptor antibody(AChR-ab) levels and electrophysiological data of repetitive nerve stimulation(RNS) and single fiber electromyography(SFEMG) examinations performed with concentric needle electrode(CNE) were examined.
Results:
- No significant incremental response was observed in ASU in any of the 33(13 female, 20 male) patients. In SFEMG performed with CNE, the mean jitter(MJ) increased in 12.1% of the patients. There were MG-related findings in the clinical examination of all patients with increased MJ. AChR-ab was positive in only 1 patient. The pathologies of those who were operated on(63.6%) were thymoma in 42.8%, thymic hyperplasia in 33.3%, thymic cyst in 9.5%, thymic remnant in 9.5%, diffuse large B-cell lymphoma in 4.7%, typical carcinoid tumor in 4.7% and adenomatous nodule in 4.7%. Although no significant relationship was observed between pathological subtypes and electrophysiological findings, the patient with the highest mean jitter value had diffuse large B-cell lymphoma.
Conclusions:
This study has shown that in patients consulted with thymic pathologies and neurological clinics, in the absence of clinical symptoms related to MG, serological and electrophysiological tests may increase the diagnostic burden. Furthermore, if there are clinical suspicions, relying solely on ASU evaluations is not sufficient; TLEMG test is necessary.