Postoperative cognitive dysfunction (POCD) is one of the most common complications after surgery under general anesthesia and usually manifests as newly presented cognitive impairment. However, the mechanism of POCD is still unclear. In addition to neurons, glial cells including microglia, astrocytes and oligodendrocytes, represent a large cell population in the nervous system. The bi-directional communication between neurons and glia provides basis for neural circuit function. Recent studies suggest that glial dysfunctions may contribute to the occurrence and progress of POCD. In this paper, we review the relevant work on POCD, which may provide new insights into the mechanism and therapeutic strategy for POCD.
ObjectiveTo investigate the changes in the nerve fiber layer of the cornea in patients with demyelinating optic neuritis (DON) and its correlation with visual acuity. MethodsA cross-sectional study. From March 2021 to July 2022, 27 cases (39 eyes) of DON patients diagnosed in the Department of Neurology and Ophthalmology of Beijing Tongren Hospital Affiliated to Capital Medical University were enrolled in this study. According to the serological test results, the patients were divided into aquaporin 4 antibody associated optic neuritis (AQP4-ON group) and myelin oligodendrocyte glycoprotein antibody associated optic neuritis (MOG-ON group), with 15 cases (19 eyes) and 12 cases (20 eyes) respectively. According to previous history of glucocorticoid treatment, the patients were divided into glucocorticoid treated group and non-glucocorticoid treated group, with 17 cases (27 eyes) and 10 cases (12 eyes) respectively. Twenty healthy volunteers (20 eyes) with age- and gender-matched were selected as the control group. All eyes underwent best corrected visual acuity (BCVA) and in vivo confocal microscopy (IVCM) examinations. BCVA was performed using Snellen's standard logarithmic visual acuity chart, which was converted into logarithmic minimum angle resolution (logMAR) visual acuity during statistics. The corneal nerve fiber length (CNFL), corneal nerve fiber density (CNFD), corneal nerve fiber branch length (CNBL), corneal nerve fiber branch density (CNBD) and the density of corneal dendritic cells (DC) were detected by IVCM examination. Parameter comparison between groups by t-test and Kruskal-Wallis rank sum test. The correlation between logMAR BCVA and pamameters of corneal nerve fibers were analyzed using Spearman analysis. ResultsThe CNFL, CNFD, and CNBL of the DON group and the control group were (10.67±2.55) mm/mm2, (57.78±12.35) root/mm2, (3.27±1.34) mm/mm2, and (13.74±3.05) mm/mm2, (70.95±13.14) root/mm2, and (4.22±1.03) mm/mm2, respectively; the difference in CNFL, CNFD, and CNBL between the two groups were statistically significant (t=4.089, 3.795, 2.773; P＜0.05). The CNFL, CNBL, and CNBD of the affected eyes in the MOG-ON group and AQP4-ON group were (12.02±2.13) mm/mm2, (3.80±1.19) mm/mm2, (47.97±8.86) fibers/mm2, and (9.25±2.19) mm/mm2, (2.72±1.19) mm/mm2, (39.43±13.86) fibers/mm2, respectively; the differences in CNFL, CNBL, and CNBD between the two groups were statistically significant (t=－4.002, －2.706, －2.306; P＜0.05). The corneal DC density of the patients in the hormone treated group and the non-hormone treated group was (24.43±8.32) and (41.22±9.86) cells/mm2, respectively. The difference in corneal DC density between the two subgroups was statistically significant (P＜0.001). Correlation analysis showed that there was a significant negative correlation between logMAR BCVA and CNBL and CNFL in patients with DON (r=－0.422, －0.456; P＜0.05). ConclusionsThere are different degrees of corneal nerve fiber damage in patients with different types of DON. There was a negative correlation between BCVA and the length of corneal nerve fibers.
ObjectiveTo analyze the prognostic factors of vision of myelin oligodendrocyte glycoprotein (MOG) antibody positive associated optic neuritis (ON) after methylprednisolone pulse therapy. MethodsA clinical observational study. A total of 32 patients (47 eyes) with MOG antibody positive ON were observed and followed up in the ophthalmology department of Beijing Tongren Hospital Affiliated to Capital Medical University and Beijing Puren Hospital from March 2019 to January 2022. Clinical data including the best corrected visual acuity (BCVA) and orbital magnetic resonance imaging were recorded. The BCVA was examined by Snellen visual acuity chart, which was finally converted into the logarithm of the minimal angle of resolution (logMAR) for statistical analysis. There were 22 case (38 eyes) with complete image data. All patients were treated with intravenous methylprednisolone pulse (IVMP) for 3-5 days. According to the intervention time (from onset to glucocorticoid treatment), the patients were divided into three groups: ＜7 d group, 7-14 d and ＞14 d group, with 16, 13, 11 eyes, respectively. The median follow-up time was 28 months. After 1 week, 1, 3 and 6 months treatment, the same equipment and methods were used for relevant examinations to observe the changes of visual acuity and the factors influencing the prognosis of visual acuity after IVMP treatment. Logistic regression and linear regression were used to analyze the prognostic correlation factors. Receiver operating characteristic (ROC) curve was used to determine the critical cut-off point of intervention timing. ResultsAmong the patients, 16 were male and 16 were female. The median onset age was 26 years. The onset duration time was 5-60 days. There were 18 cases (56.3%, 18/32) with abnormal serum immune indexes. The initial symptom was decreased vision with unilateral or bilateral ON. Seventeen (53.1%, 17/32) cases had unilateral ON and 15 (46.9%, 15/32) cases with bilateral ON. Thirty-six eyes (76.6%, 36/47) got optic disc edema, 37 eyes (78.7%, 37/47) accompanied by pain of ocular movement. The nadir logMAR BCVA was mean 1.69±0.13. Long T2WI signals with segmental thickening in the orbital segment of the optic nerve were obtained in 27 eyes (71.1%, 27/38) and in 24 eyes (63.2%, 24/38) with optic nerve and sheath enhancement. During the follow-up period, there were 10 cases of relapse (31.3%, 10/32). The logMAR BCVA of attacked eyes were 0.52±0.09, 0.22±0.06, 0.12±0.06, 0.10±0.06 at 1 week and 1, 3 and 6 months after IVMP treatment, respectively. The rate of BCVA improvement was the fastest at 1 week after treatment, and BCVA returned to stability at 3 months. Logistic regression analysis showed that the timing of intervention was significantly correlated with the prognosis of vision in primary onset patients (odds ratio=12.17, P=0.006), with a negative linear regression relationship (r=－0.48, 95% confidence interval －0.71-－0.17, P=0.008). Comparing the logMAR BCVA between the intervention time ＞14 group with the ＜7 group and the 7-14 group, there were statistically significant difference (P=0.017, 0.037), respectively. The cut-off point of ROC curve to predict the optimal intervention time was 13.5 days. Other factors such as: gender, age, predisposing factor, pain of eye motion, edema of optic disc, bilateral ON, imaging changes, abnormal autoimmune indicators were not associated with the prognosis of visual acuity. ConclusionThe timing of hormone intervention in primary onset patients is an important factor affecting the prognosis of vision and the optimal intervention time window of IVMP is two weeks.