phosphocreatine and Bulbo-Spinal-Atrophy--X-Linked

The purpose of this study was to investigate the metabolic abnormalities in Kennedy disease (KD) patients using proton magnetic resonance spectroscopy. Five patients with KD showing typical phenotype were compared with eight age-matched, healthy control subjects. Relative metabolite concentrations for N-acetyl-aspartate (NAA), choline (Cho) and phosphocreatine (Cr) and lactate (Lac) were measured in the motor cortex and the brainstem area. In the motor cortex, NAA/Cr ratio was significantly reduced in KD patients (P=0.04). In the brainstem area, metabolic ratios including NAA/Cho, NAA/Cr and Cho/Cr failed to show significant difference between KD patients and normal controls. No pathologic Lac signal was noted in patients and controls. These findings corroborate a previous study indicating an involvement of the motor cortices in patients with KD.

Topics: Adult; Aspartic Acid; Brain Stem; Bulbo-Spinal Atrophy, X-Linked; Choline; Humans; Lactic Acid; Magnetic Resonance Spectroscopy; Male; Middle Aged; Motor Cortex; Phosphocreatine; Protons

Diagnostic confidence in motor neuron disease may be improved by the use of advanced MR imaging techniques. Our aim was to assess the accuracy (sensitivity/specificity) and agreement of combined (1)H-MR spectroscopy (proton MR spectroscopy) and diffusion tensor imaging (DTI) at 3T in patients with suspected motor neuron disease regarding detection of upper motor neuron (UMN) dysfunction.. Eighteen patients with suspected motor neuron disease were studied with MR spectroscopy/DTI and clinically rated according to the El-Escorial and ALSFRS-R scales. For MR spectroscopy, absolute N-acetylaspartate (NAA), choline (Cho), and phosphocreatine (PCr) concentrations and relative NAA/Cho and NAA/PCr ratios of corresponding volumes of interest within the primary motor cortex were calculated. For DTI, fractional anisotropy (FA) and mean diffusivity (MD) were measured bilaterally at the level of the precentral gyrus, corona radiata, internal capsule, cerebral peduncles, pons, and pyramid. FA and MD statistics were averaged on the corticospinal tracts (CSTs) as a whole to account for a region-independent analysis.. MR spectroscopy indicated NAA reduction beyond the double SD of controls in 6 of 8 patients with clinical evidence for UMN involvement. Congruently, the mean FA of these patients was significantly lower in the upper 3 regions of measurements (P < .01). Overall, MR spectroscopy and DTI were concordant in all except 3 cases: 1 was correctly excluded from motor neuron disease by DTI (genetically proved Kennedy syndrome), whereas MR spectroscopy indicated CST involvement. MR spectroscopy and DTI each were false-positive for CST affection in 1 patient with lower motor neuron involvement only.. Combined MR spectroscopy/DTI at 3T effectively adds to the detection of motor neuron disease with a high degree of accordance.

Topics: Adult; Aged; Anisotropy; Aspartic Acid; Brain; Bulbo-Spinal Atrophy, X-Linked; Choline; Diagnosis, Differential; Diffusion Magnetic Resonance Imaging; Dominance, Cerebral; Female; Follow-Up Studies; Humans; Image Processing, Computer-Assisted; Magnetic Resonance Spectroscopy; Male; Middle Aged; Motor Cortex; Motor Neuron Disease; Neurologic Examination; Phosphocreatine; Sensitivity and Specificity