Assessment of neural alterations in obstructive sleep apnoea syndrome: can apparent diffusion coefficient measurements be useful?

Background and Aims Our aim was to investigate whether neurological alteration in patients with obstructive sleep apnoea syndrome (OSAS) with apparently normal cerebral and cerebellar structures can be assessed by means of apparent diffusion coefficient (ADC) measurement and to investigate the association between OSAS severity and ADC values. Methods Following the acquisition of diffusion‐weighted cranial magnetic resonance imaging, ADC measurements were performed in 24 different apparently normal cerebral and cerebellar structures, including the bilateral frontal and parietal cortices, insulae, cingulate gyri, hippocampi, frontal and parieto‐occipital periventricular white matter (PWM), caudate nuclei, putamen, thalami, cerebellar hemispheres, pons and mesencephalon in 47 OSAS patients and 20 control subjects. The ADC values of the patients and the control group were compared. The association between the apnoea–hypopnoea index (AHI) and the ADC values of the patients were investigated. Results The ADC values in the bilateral frontal PWM were lower in the patient group than those in the control subjects (P