An Unusual Presentation of Dermatomyositis With Muscle Hypertrophy

Area of Science:

• Neurology
• Immunology
• Clinical Electrophysiology

Background:

• Peripheral nerve hyperexcitability is a rare neurological disorder.
• It is characterized by spontaneous motor unit activity.
• While associated with various immune-mediated conditions, its link to dermatomyositis is seldom reported.

Observation:

• A 65-year-old woman presented with serological and muscle biopsy findings consistent with dermatomyositis.
• She experienced significant muscle hypertrophy, stiffness, and delayed muscle relaxation.
• Electrodiagnostic studies revealed peripheral nerve hyperexcitability.

Findings:

• The patient's presentation included features characteristic of Isaacs syndrome.
• This suggests a rare overlap between dermatomyositis and peripheral nerve hyperexcitability.

Implications:

• This case expands the known clinical spectrum of dermatomyositis.
• It underscores the importance of considering peripheral nerve hyperexcitability in dermatomyositis patients with specific symptoms.
• Further research may elucidate shared pathophysiological mechanisms between these conditions.