Clinical Report: Myokymia as a Presentation of Anti-IgLON5 Disease

Overview

This case report describes a 53-year-old male with anti-IgLON5 disease presenting with generalized myokymia. Laboratory tests revealed positive anti-IgLON5 IgG antibodies in serum (titer 1:100) and CSF (titer 1:1).

Background

Anti-IgLON5 disease is a rare autoimmune neurological disorder characterized by autoantibodies targeting the IgLON5 protein. It presents with diverse clinical manifestations, including neuromuscular symptoms like myokymia, which can be misdiagnosed.

Data Highlights

Laboratory tests revealed positive anti-IgLON5 IgG antibodies in serum (titer 1:100) and CSF (titer 1:1). The patient experienced symptom alleviation after treatment, with antibody titers declining to negative within 3 months.

Key Findings

• The patient had a history of intermittent generalized myokymia for 8 months prior to diagnosis.
• Myokymia was observed in multiple muscle groups and was exacerbated by emotional stress.
• Initial treatments with baclofen and acupuncture were ineffective.
• Combined treatment with efgartigimod and oral prednisone led to alleviation of symptoms.
• During an 18-month follow-up, symptoms abated within the first 6 months.
• Antibody titers fluctuated, with a mild recurrence of symptoms at 7 months post-treatment.

Clinical Implications

This case highlights the importance of screening for anti-IgLON5 antibodies in patients presenting with myokymia.

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