Study of 1 H-MR spectroscopy in obstructive sleep apnea syndrome

Objective:Using 1 H magnetic resonance spectroscopy imaging(1H-MRSI)to investigate the cerebrai metabolic changes in patients with obstructive sleep apnea syndrome(OSAS).Methods:1H-MRS and was performed in 33 patients with OSAS and 20 control subjects,the patients were classified into two groups based on the results of polysomnography(PSG): mild OSAS(16 patients) or moderate to severe OSAS(17 patients).Cerebral metabolism was studied by assessing the ratios of nitro-acetyl aspartate to choline(NAA/Cho) as well as to creatine(NAA/Cr),and the ratio of choline to creatine(Cho/Cr) ratios for cerebral cortex and white matter were calculated separately.Results:In the patients with moderate to severe OSAS,the NAA/Cho ratio(1.56±0.21) for the white Matte was significantly different and lower than that in patients with mild OSAS(1.88±0.23) and healthy subjects(1.89±0.25)(P0.01).The ratios of NAA/Cr and Cho/Cr had no obvious changes(P0.05).However,no significant difference in the three metabolic ratios was found between patients with mild OSAS and control subjects for cerebral white matter,as well as three groups for cerebral cortex(P0.05).Conclusion:Abnormal cerebral metabohc changes in patients with OSAS could be demonstrated by 1 H-MRSI.