Isaacs syndrome : A rare clinical entity

Abstract

Neuromyotonia is a rare syndrome of continuous motor unit activity of peripheral nerve origin that manifests as various combinations of muscle stiffness, cramps, twitching and weakness. Isaacs syndrome is a form of acquired neuromyotonia due to an underlying autoimmune or paraneoplastic mechanism. We wish to report a case of acquired paraneoplastic neuromyotonia presented in neurology outpatient department with painful twitching of muscles all over the body for the last 6 months. While searching for an underlying cause a mass lesion was found in anterior mediastinum on radio imaging suggestive of tumor. Patient was treated with antiepileptic drugs and intravenous immunoglobulins. Tumor was removed through thoracoscopic surgery, which on histopathological examination was confirmed as thymoma. Patient responded well to treatment and after a month patient was completely asymptomatic with no fresh complaints.