Consequences of misdiagnosing mitochondrial disorder.
Diagnosing mitochondrial disorder remains a challenge. In a 75-year-old women, with short stature, muscle cramps, ptosis, fasciculations and progressive, proximal limb weakness and wasting, hyponatriemia, abnormal lactate-stress-test, and slightly abnormal electromyography, muscle biopsy suggested granulomatous myositis. Corticosteroids and azathioprin were ineffective. After a second work-up amyotrophic-lateral-sclerosis was diagnosed. Riluzole was started, without effect. She developed respiratory insufficiency, requiring mechanical ventilation. Apical ballooning was found. After switching to non-invasive positive pressure ventilation and physiotherapy, she markedly improved. After a third diagnostic work-up, mitochondrial disorder was suspected. Unfortunately, she died suddenly from a cardiac arrhythmia at home. Mitochondrial disorder may mimic motor neuron disease, muscle biopsy may mimic myositis, and may show only little evidence for respiratory chain disorder.
Finsterer
Josef
J
Krankenanstalt Rudolfstiftung, Vienna, Austria. duarte@aonmail.at
D000368:Aged; D000690:Amyotrophic Lateral Sclerosis / Q000175:diagnosis; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D028361:Mitochondrial Diseases / Q000175:diagnosis* / Q000188:drug therapy / Q000503:physiopathology; D011175:Positive-Pressure Respiration / Q000379:methods; D012131:Respiratory Insufficiency / Q000175:diagnosis / Q000209:etiology* / Q000628:therapy