The Application Value Of Magnetic Resonance Spectroscopy In Evaluating The Cognitive Function Of Adult OSAHS Patients

1 ObjectiveAt present,the assessment of cognitive function of patients with obstructive sleep apnea-hypopnea syndrome（OSAHS）is mainly made with through a variety of cognitive scales.However,there are same subjective interference factors in these scales.Magnetic resonance spectroscopy（MRS）can objectively analyze the metabolism of living tissue,but it is seldom used in cognitive function research.The value of MRS in evaluating the cognitive function in OSAHS patients were discussed in this study.2 MethodsA total of 90 patients aged 40 to 60 years old were selected from December 2016 to May2017 at the sleep medical center of Gansu Provincial People’s Hospital.According to Polysomnography（PSG）,the results were divided into 60 cases of OSAHS and 30 cases of non-OSAHS.All patients were analyzed by magnetic resonance spectroscopy in the hippocampus.The area under the curve of N-acetyl aspartic acid（NAA）,choline（Cho）,and creatine（Cr）were automatically calculated by the magnetic resonance system.Finally,the general data of the experimental group and the control group,the Montreal cognitive assessment（MoCA）score,and the changes of MRS metabolism in the hippocampus were respectively calculated.3 Results（1）The baseline data of the two groupsIn the two groups,the body mass index（BMI）,the lowest oxygen saturation（SaO₂）,the mean oxygen saturation（SaO₂）,and the apnea hypopnea index（AHI）were statistical difference（all P<0.05）.（2）Comparison of two groups of Montreal cognitive assessment scale（MoCA）The total score of MoCA,visuospatial and executive ability,delayed memory and attention scores in OSAHS group were lower than non-OSAHS group（all P<0.05）.（3）Comparison of the incidence of cognitive dysfunction in two groups of cognitive impairment and OSAHS patients with different degreesThe incidence of cognitive dysfunction in the two groups was statistical difference,and the incidence of cognitive dysfunction in OSAHS patients with different degrees had statistical difference,and the incidence of cognitive dysfunction between mild and severe was statistical difference.（all P<0.05）.（4）Logistic Regression analysis of influencing factors of cognitive impairment in patients Age might be a risk factor for cognitive dysfunction in OSAHS patients and the lowest SaO₂might be a protective factor for cognitive dysfunction in OSAHS patients（P<0.05）.（5）Comparison of MRS results in the hippocampus of two groups of patients The value of NAA/Cr,Cho/Cr and NAA/Cho in the hippocampus of OSAHS group were all decreased,There was statistical difference in the two groups（all P<0.05）.（6）Comparison of metabolic ratios of magnetic resonance spectroscopy in hippocampus of patients with different degrees of OSAHSThe NAA/Cr and Cho/Cr value of mild,moderate and severe were statistical difference.NAA/Cr value in mild and moderate,mild and severe,moderate and severe were statistical difference,Cho/Cr value in mild and severe were statistical difference（all P<0.05）.（7）Linear regression analysis of MoCA total score and MRS in the hippocampus There was a positive correlation relationship between the total score of MoCA and the value of NAA/Cr,and the results were statistical difference（P<0.05）.（8）Linear regression analysis of MoCA and MRS in the hippocampus The visual space was positively correlated with the execution force and NAA/Cho value.Delayed memory was positively correlated with NAA/Cr value.Attention was positively correlated with NAA/Cr value,and the results were statistical difference（all P<0.05）.4 ConclusionsAdult OSAHS cognitive dysfunction is mainly manifested in visual space and executive ability,delayed memory,attention and so on.The incidence of cognitive dysfunction in OSAHS group was significantly higher than non-OSAHS group,and severe OSAHS patients were more likely to develop cognitive impairment.The lower the age and the lowest SaO₂,the greater the risk of cognitive dysfunction in OSAHS patients.The value of NAA/Cr,Cho/Cr,NAA/Cho of the OSAHS group in the hippocampal decreased and The value of NAA/Cr,Cho/Cr decreased with the severity of OSAHS.The NAA/Cr value decreases with the reduction of the total MoCA score.The NAA/Cho value decreases with the decrease of visual space and executive power,and the NAA/Cr value decreases with delayed memory and decreased attention.It indicates that MRS in hippocampal has important application value in objective assessment of cognitive function in OSAHS patients.