Long-term brain metabolic alterations in exogenous Cushing's syndrome as monitored by proton magnetic resonance spectroscopy

The effects of exogenous Cushing's syndrome on the brain metabolism were in vestigated by proton magnetic resonance spectroscopy (MRS). Thirteen patien ts having been treated for 2 to 22 years with prednisone were recruited. On the average, none of the metabolites (NAA, Cr, Cho and ml) were significan tly different from those of 40 normal subjects in any of the three regions studied: frontal area, thalamus and temporal area. However, the Cho/H2O rat ios were found to decrease significantly in the thalamic area as a function of treatment period (-1.3%/year). In the frontal and temporal areas, decre ases of the Cho/H2O ratios were measured with treatment period but they did not reach statistical significance. Effects on Cho levels can be related t o those observed for patients with endogenous Cushing's syndrome and sugges t an impairment at the membrane level. The Cho/H2O reductions were not foun d to be dose- or age-dependent. Other metabolite ratios did not vary with t reatment period, dose or age. (C) 2001 Elsevier Science B.V. All rights res erved.