title: Fibrous myopathy as a complication of repeated intramuscular injections for chronic headache.
abstract: Two cases of fibrous myopathy associated with repeated, long-term intramuscular injections for treatment of chronic temporomandibular joint pain and chronic headache, respectively, are described. Both patients developed severe, function-limiting contractures in upper and lower extremity muscles used as injection sites. In one of the cases, the contractures were painful. Electrophysiological testing, magnetic resonance imaging and muscle biopsy results were all consistent with myopathy and replacement of skeletal muscle with noncontractile fibrous tissue. These cases are presented to increase awareness of fibrous myopathy and to promote surveillance for this serious potential complication of long-term intramuscular injections in chronic headache and other pain patients.
authors.affiliation: University of Alberta, Division of Physical Medicine and Rehabilitation, Edmonton, Alberta.
authors.forename: R
authors.initials: R
authors.lastname: Burnham
authors.forename: S
authors.initials: S
authors.lastname: McNeil
authors.forename: C
authors.initials: C
authors.lastname: Hegedus
authors.forename: D S
authors.initials: DS
authors.lastname: Gray
mesh_terms: D000328:Adult; D018450:Disease Progression; D005260:Female; D020773:Headache Disorders / Q000150:complications*; D006801:Humans; D007273:Injections, Intramuscular / Q000009:adverse effects*; D008279:Magnetic Resonance Imaging / Q000379:methods; D018485:Muscle Fibers, Skeletal / Q000473:pathology*; D009135:Muscular Diseases / Q000209:etiology* / Q000473:pathology; D013705:Temporomandibular Joint Disorders / Q000188:drug therapy