Abnormality of the myocardial sympathetic nervous system in a patient with Becker muscular dystrophy detected with iodine-123 metaiodobenzylguanidine scintigraphy.
OBJECTIVE
This study was performed to determine whether I-123 metaiodobenzylguanidine (MIBG) scintigraphy can depict myocardial sympathetic nerve abnormalities in Becker muscular dystrophy.


METHODS
A 34-year-old man with Becker muscular dystrophy underwent Tl-201 and I-123 MIBG scintigraphy sequentially before and 4 months after the beginning of oral administration of enalapril maleate, an angiotensin-converting enzyme inhibitor.


RESULTS
Before and during treatment, stress Tl-201 scintigraphy revealed nonreversible myocardial perfusion defects in the anterior, inferoposterior, and apical walls, and I-123 MIBG scintigraphy depicted a region with decreased sympathetic nerve function or innervation. Before treatment, the I-123 MIBG heart count- mediastinum count (H:M) ratio was 2.1 and the washout rate was 21% on delayed images obtained 4 hours after the injection of I-123 MIBG, indicating hyperactivity of the sympathetic nervous system in the myocardium. During treatment, the H:M ratio was 3.0 and the washout rate was 15%.


CONCLUSIONS
With I-123 MIBG scintigraphy it is possible to evaluate an abnormality of the myocardial sympathetic nervous system and the efficacy of administration of an angiotensin-converting enzyme inhibitor in this disease.
Kaminaga
T
T
Department of Radiology, Teikyo University School of Medicine, Tokyo, Japan. kami@med.teikyo-u.ac.jp
Matsumura
K
K
Hatanaka
H
H
Shimizu
T
T
D000328:Adult; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000008:administration & dosage; D001342:Autonomic Nervous System Diseases / Q000000981:diagnostic imaging* / Q000209:etiology; D004656:Enalapril / Q000008:administration & dosage; D005080:Exercise Test; D005500:Follow-Up Studies; D006321:Heart / Q000000981:diagnostic imaging* / Q000294:innervation*; D006801:Humans; D007457:Iodine Radioisotopes; D007462:Iodobenzenes; D008297:Male; D020388:Muscular Dystrophy, Duchenne / Q000150:complications / Q000000981:diagnostic imaging* / Q000188:drug therapy; D011877:Radionuclide Imaging; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index
D000806:Angiotensin-Converting Enzyme Inhibitors; D007457:Iodine Radioisotopes; D007462:Iodobenzenes; D004656:Enalapril