Proton MRS in Kennedy disease: absolute metabolite and macromolecular concentrations.

PURPOSE: To investigate whether glutamine and glutamate (Glx) were elevated in Kennedy Disease (KD), and whether pathological proteins were spectroscopically visible as altered macromolecular (MM) resonances.

MATERIALS AND

METHODS

Ten patients with KD and twelve healthy volunteers were investigated using a stimulated echo acquisition mode (STEAM) spectroscopy sequence with metabolite-nulling.

RESULTS

The concentrations of Glx remained unchanged in KD. An increased myo-inositol (Ins), and elevated MM at 0.9 ppm were found within the motor area. The N-acetyl-aspartate (NAA)/creatine (Cr) ratio was negatively correlated to the number of cytosine adenosine guanine (CAG) repeats in the motor area.

CONCLUSION

The elevated MM at 0.9 ppm may be attributed to a pathologically altered protein in KD. Additionally, the changes of Ins point to a clinically unexpected involvement of the motor cortex. The correlation of NAA/Cr with the number of CAG repeats indicates a link between metabolites and genetic failure.