Inclusion Body Myositis

Etiology

  • Autoimmune d/o affecting muscles

Risk Factors

  • Age > 50
  • Male>female

Symptoms

  • Slowly progressive
  • Weakness w/o pain
  • No sensory impairment
  • Typically symmetric
  • Distal > proximal, in particular finger flexors (grip) and quadriceps (difficulty getting out of chairs, falls)
  • ~50% ultimately w/dysphagia
  • 20+% assoc w/connective tissue d/o

Physical Exam Findings

  • Progressive weakness, often finger flexors and quadriceps first
  • Atrophy of affected muscles
  • Distal > proximal
  • Reflexes diminish w/disease progression

Tests