Near-infrared brain functional characteristics of mild cognitive impairment with sleep disorders

BACKGROUND Mild cognitive impairment (MCI) has a high risk of progression to Alzheimer’s disease. The disease is often accompanied by sleep disorders, and whether sleep disorders have an effect on brain function in patients with MCI is unclear. AIM To explore the near-infrared brain function characteristics of MCI with sleep disorders. METHODS A total of 120 patients with MCI (MCI group) and 50 healthy subjects (control group) were selected. All subjects underwent the functional near-infrared spectroscopy test. Collect baseline data, Mini-Mental State Examination, Montreal Cognitive Assessment scale, fatigue severity scale (FSS) score, sleep parameter, and oxyhemoglobin (Oxy-Hb) concentration and peak time of functional near-infrared spectroscopy test during the task period. The relationship between Oxy-Hb concentration and related indexes was analyzed by Pearson or Spearmen correlation. RESULTS Compared with the control group, the FSS score of the MCI group was higher (t = 11.310), and the scores of Pittsburgh sleep quality index, sleep time, sleep efficiency, nocturnal sleep disturbance, and daytime dysfunction were higher (Z = -10.518, -10.368, -9.035, -10.661, -10.088). Subjective sleep quality and total sleep time scores were lower (Z = -11.592, -9.924). The sleep efficiency of the MCI group was lower, and the awakening frequency, rem sleep latency period, total sleep time, and oxygen desaturation index were higher (t = 5.969, 5.829, 2.887, 3.003, 5.937). The Oxy-Hb concentration at T0, T1, and T2 in the MCI group was lower (t = 14.940, 11.280, 5.721), and the peak time was higher (t = 18.800, 13.350, 9.827). In MCI patients, the concentration of Oxy-Hb during T0 was negatively correlated with the scores of Pittsburgh sleep quality index, sleep time, total sleep time, and sleep efficiency (r = -0.611, -0.388, -0.563, -0.356). It was positively correlated with sleep efficiency and total sleep time (r = 0.754, 0.650), and negatively correlated with oxygen desaturation index (r = -0.561) and FSS score (r = -0.526). All comparisons were P < 0.05. CONCLUSION Patients with MCI and sleep disorders have lower near-infrared brain function than normal people, which is related to sleep quality. Clinically, a comprehensive assessment of the near-infrared brain function of patients should be carried out to guide targeted treatment and improve curative effect.