Inclusion body myositis: diagnosis, pathogenesis, and treatment options.

Inclusion body myositis (IBM) is the most common acquired myopathy in people older than 50 years. IBM typically presents with distal upper extremity weakness accompanied by proximal lower extremity muscle weakness. Associated clinical findings include asymmetric weakness, foot drop, and dysphagia. The pathogenesis of IBM is not clear. In this article the authors briefly discuss postulated pathogenic mechanisms. Although no proven pharmacotherapy exists, some promising candidates are discussed.