Co-occurrence of multiple sclerosis and Thomsen's myotonia: a report of two cases

Abstract

Multiple sclerosis (MS) is a common demyelinating disease of the central nervous system in which an abnormal immune system response results in damage to the myelin sheaths surrounding nerves. The etiology of MS remains elusive, although it has been suggested to be influenced by both genetic and environmental factors. Here, we report two exceptional cases of patients affected by both MS and Thomsen's myotonia. Electromyography and MRI scans confirmed the presence of both diseases in the referred cases. Although the mechanisms underlying the co-occurrence of MS and Thomsen's disease are unclear, we have endeavored to offer plausible explanations for it.

Figure 1

The MRI scan of two MS patients suffering from Thomsen myotonia (A) Cranial FLAIR MRI (left) and spine MRI (right) showing numerous demyelinating plaques in periventricular and centrum semiovale areas of the brain and white matter of the spinal cord. (B) Brain FLAIR MRI demonstrating numerous periventricular hypersignal lesions.

Figure 2

The pedigrees of both patients show a dominant mode of inheritance indicating Thomsen form of myotonia congenita. (A) Three patients with MC were detected in the first pedigree (case 1). No other MS patient was observed in this family. (B) Seven MC patients were diagnosed in the second pedigree (case 2). No members of this family were affected by MS.