Poster 197: Inflammatory Myopathy in a Diabetic Presenting With Foot Drop: A Case Report

Abstract

Setting: Outpatient clinic. Patient: A 29-year-old man referred for electrodiagnostics with 1 year complaint of progressive foot drop and ataxia. Case Description: Patient has medical history of poorly controlled diabetes type 1 (diagnosed 14 years prior), hyperlipidemia (with current statin use), hypertension, and depression. History of present illness revealed proximal and distal weakness in upper and lower extremities and numbness in stocking and glove distribution. Lumbar magnetic resonance imaging showed disk herniations with no stenosis. The patient denied back pain, radicular pain, muscle aches, or family history of neurologic conditions. Physical exam revealed diffuse atrophy, proximal and distal weakness with trace bilateral ankle dorsiflexion, absent reflexes, and normal muscle tone. Electrodiagnostics revealed a sensorimotor peripheral polyneuropathy with neuropathic findings on electromyography (EMG) without specific myopathic features. Lab studies revealed CPK greater than 1000, elevated aldolase, ESR greater than 100, and a negative rheumatologic panel. Muscle biopsy was suggestive of a chronic myopathy, possibly inflammatory, with features of neurogenic atrophy. Assessment/Results: This patient's clinical picture and diagnostics are suggestive of multifactorial weakness—due to a chronic inflammatory myopathy—polymyositis versus statin-induced myopathy, with a superimposed diabetic neuropathy. The patient has been discontinued from statins, started on corticosteroids and azathioprine, fitted with bilateral ankle foot orthoses, and treated with physical therapy. His functional status remains stable with ongoing treatment. Conclusions: Correlation of thorough history, physical exam, and diagnostics is essential for appropriate diagnosis and treatment. EMG findings for this patient were suggestive of a neuropathic process, while physical exam also suggested a myopathic process. Through laboratory and histologic studies a more complete pathophysiology and treatment plan was formed. It is important to remember that weakness can be multifactorial. Complex cases where history and physical do not correlate with findings necessitate further diagnostic investigation, consideration, and cross-specialty physician collaboration to achieve the best patient outcomes.