Inclusion body myositis presenting with isolated erector spinae paresis

Area of Science:

• Neurology
• Myology
• Pathology

Background:

• Inclusion body myositis (IBM) is a progressive, degenerative muscle disease affecting adults.
• Characterized by insidious onset of muscle weakness, typically in the quadriceps and forearm extensors.
• Diagnostic challenges include differentiating IBM from other myopathies.

Observation:

• A 70-year-old patient presented with a 4-year history of paravertebral muscle weakness.
• Electrodiagnostic studies showed a mixed neurogenic-myopathic pattern.
• Muscle biopsy revealed atrophic fibers with rimmed vacuoles.

Findings:

• Electron microscopy identified characteristic 16 nm cytoplasmic and intranuclear filaments, confirming inclusion body myositis.
• Corticosteroid therapy resulted in only mild and transient symptomatic improvement.
• Disease progression was observed over a 10-month follow-up period.

Implications:

• This case highlights the diagnostic features of inclusion body myositis, including electrodiagnostic and histopathological findings.
• The limited efficacy of corticosteroids underscores the need for novel therapeutic strategies for IBM.
• Understanding disease progression is crucial for patient management and future clinical trial design.