BRAIN ABNORMALITIES IN DUCHENNE MUSCULAR-DYSTROPHY - P-31 MAGNETIC-RESONANCE SPECTROSCOPY AND NEUROPSYCHOLOGICAL STUDY

Duchenne muscular dystrophy (DMD) is one of a range of muscular dystro phies caused by abnormalities of the short arm of the X chromosome (Xp 21), which often cause mental retardation in addition to progressive m uscular weakness. Normal dystrophin expression is lacking in both skel etal muscle and brain of affected subjects. Phosphorus-Si magnetic res onance spectroscopy has shown several abnormalities in skeletal muscle in DMD. We looked for similar abnormalities in brain in patients with DMD and related the findings to neuropsychological test results. We s tudied by magnetic resonance spectroscopy 19 boys (aged 76-167 months) diagnosed as having DMD and 19 control boys of similar age (87-135 mo nths). intelligence quotient (IQ) was assessed with the Wechsler Intel ligence Scale for children. The DMD patients had significantly higher values than the controls in the brain ratios of inorganic phosphate to adenosine triphosphate (mean 0.53 [SD 0.21] vs 0.36 [0.09], p=0.003), to phosphomonoesters (0.40 [0.07] vs 0.29 [0.07], p=0.0001), and to p hosphocreatine (0.44 [0.10] vs 0.37 [0.08], p=0.02). There were signif icant differences between the DMD patients and the controls in full-sc ale IQ (76 [16] vs 101 [16], p=0.0001), performance IQ (78 [17] vs 94 [14], p=0.003), and verbal IQ (78 [17] vs 106 [17], p=0.0001). These a ltered metabolite ratios parallel the findings in dystrophic muscle an d suggest bioenergetic similarities in tissues that lack dystrophin.