Short ReportAdult-Onset Acid Maltase Deficiency With Isolated Axial Muscle InvolvementSalem, Bassel MD*; Thaisetthawatkul, Pariwat MD*; Fernandes, J Americo MD*; McComb, Rodney D MD†Author Information From the Departments of *Neurological Sciences; and †Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE. Reprints: Pariwat Thaisetthawatkul, MD, 982045 Nebraska Medical Center, Omaha, NE 68198-2045 (e-mail: [email protected]). Journal of Clinical Neuromuscular Disease: September 2010 - Volume 12 - Issue 1 - p 30-35 doi: 10.1097/CND.0b013e3181d7c323 Buy Metrics Abstract Introduction: We report a patient with acid maltase deficiency who presented with subacute respiratory failure as the first symptom without significant extremity weakness. Methods and Results: Electromyography of extremities was normal but showed myopathic changes and myotonic discharges limited to axial muscles only. Muscle biopsy confirmed the diagnosis. Conclusion: It is essential to examine axial muscles during electromyography if a patient presents with respiratory failure of unclear etiology even if the clinical examination does not show significant weakness in the extremities and electromyographic findings in the extremities are unremarkable. © 2010 Lippincott Williams & Wilkins, Inc.