[Correlation between white matter lesion and memory impairment in patients with obstructive sleep apnea syndrome]

To investigate the nature of white matter lesion and correlation to memory impairment in patients with obstructive sleep apnea syndrome (OSAS) by diffusion tensor imaging ( DTI).

We conducted a cross-sectional study of 20 middle-aged male people (10 with OSAS and 10 healthy controls) group-matched by age, educational level, and socioeconomic status. DTI was performed on those people with OSAS and on matched controls. Fractional anisotropy(FA) and average diffusion coefficient(ADC) values were measured respectively in bilateral white matter of the frontal lobe, anterior cingulate gyrus, anterior cingulum, etc. At the same time, WMS values were detected respectively.

Relative to controls, patients with OSAS had a lower FA in the white matter of right frontal lobe (0.444-/+0.025), splenium of corpus callosum (0.776-/+0.028 ), left anterior cingulate gyrus (0.154-/+0.021), right anterior cingulate gyrus (0.152-/+0.017), left anterior cingulum (0.372-/+0.022), right anterior cingulum (0.351-/+0.029), left centrum semiovale (0.501-/+0.029), peripheric white matter of left anterior angle (0.242-/+0.031), peripheric white matter of left posterior angle (0.338-/+0.029), peripheric white matter of right posterior angle (0.360-/+0.022 ), left parahippocampal gyrus (0.167-/+0.027), right parahippocampal gyrus (0.177-/+0.023). Besides, FA values of OSAS patients in the white matter of right frontal lobe and left centrum semiovale were strongly positively correlated with WMS values. While in comparison with that of healthy controls, ADC of OSAS patients was significantly higher in the white matter of right frontal lobe (8.589-/+0.264 x e(-10) mm(2)/s), trunk of corpus callosum (8.197-/+0.253 x e(-10) mm(2)/s), splenium of corpus callosum (8.218-/+0.194 x e(-10) mm(2)/s), left anterior cingulate gyrus (12.151-/+0.454 x e(-10) mm(2)/s), right anterior cingulate gyrus (12.113-/+0.524 x e(-10) mm(2)/s), right anterior cingulum (8.954-/+0.177 x e(-10) mm(2)/s),left centrum semiovale (7.333-/+0.220 x e(-10) mm(2)/s) and peripheric white matter of left anterior angle (9.186-/+0.465 x e(-10) mm(2)/s).

This study indicated that white matter and gray matter was both remarkably damaged in OSAS patients, which could contribute to memory impairment.