Background: Advances in blood biomarker discovery have enabled the improved diagnosis and prognosis of Alzheimer's disease (AD). Most branched-chain amino acids, except isoleucine (Ile), are correlated with both mild cognitive impairment (MCI) and AD. Therefore, this study investigated the association between serum Ile levels and MCI/AD. Methods: This study stratified 700 participants from the Alzheimer's Disease Neuroimaging Initiative database into four diagnostic groups: cognitively normal, stable MCI, progressive MCI, and AD. Analysis of covariance and chi-square analyses were used to test the demographic data. Receiver operating curve analyses were used to calculate the diagnostic accuracy of different biomarkers and were compared by MedCalc 20. Additionally, Cox proportional hazards models were used to measure the ability of serum Ile levels to predict disease conversion. Finally, a linear mixed-effects model was used to evaluate the associations between serum Ile levels and cognition, brain structure, and metabolism. Results: Serum Ile concentration was decreased in AD and demonstrated significant diagnostic efficacy. The combination of serum Ile and cerebrospinal fluid (CSF) phosphorylated tau (P-tau) improved the diagnostic accuracy in AD compared to total tau (T-tau) alone. Serum Ile levels significantly predicted the conversion from MCI to AD (cutoff value of 78.3 μM). Finally, the results of this study also revealed a correlation between serum Ile levels and the Alzheimer's Disease Assessment Scale cognitive subscale Q4. Conclusions Serum Ile may be a potential biomarker of AD. Ile had independent diagnostic efficacy and significantly improved the diagnostic accuracy of CSF P-tau in AD. MCI patients with a lower serum Ile level had a higher risk of progression to AD and a worse cognition assessment.

BACKGROUNDNeurophysiologic monitoring during surgery is to prevent permanent neurological injury resulting from surgical manipulation. To improve the accuracy and sensitivity of intraoperative neuromonitoring, combined monitoring of transcranial electrical stimulation motor evoked potentials (TES-MEPs), somatosensory evoked potentials (SSEPs) and brainstem auditory evoked potentials (BAEPs) was attempted in microsurgery for lesions adjacent to the brainstem and intracranial aneurysms.

METHODSMonitoring of combined TES-MEPs with SSEPs was attempted in 68 consecutive patients with lesions adjacent to the brainstem as well as intracranial aneurysms. Among them, 31 patients (31 operations, 28 of posterior cranial fossa tumors, 3 of posterior circulation aneurysms) were also subjected to monitoring of BAEPs. The correlation of monitoring results and clinical outcome was studied prospectively.

RESULTSCombined monitoring of evoked potentials (EPs) was done in 64 (94.1%) of the 68 patients. MEPs monitoring was impossible for 4 patients (5.9%). No complication was observed during the combined monitoring in all the patients. In 45 (66.2%) of the 68 patients, EPs were stable, and they were neurologically intact. Motor dysfunction was detected by MEPs in 8 patients, SSEPs in 5, and BAEPs in 4, respectively.

CONCLUSIONSA close relationship exists between postoperative motor function and the results of TES-MEPs monitoring. TES-MEPs are superior to SSEPs and BAEPs in detecting motor dysfunction, but combined EPs serve as a safe, effective and invasive method for intraoperative monitoring of the function of the motor nervous system. Monitoring of combined EPs during microsurgery for lesions adjacent to the brainstem and intracranial aneurysms may detect potentially hazardous maneuvers and improve the safety of subsequent procedures.

Adolescent ; Adult ; Aged ; Brain Stem ; physiopathology ; Evoked Potentials, Auditory, Brain Stem ; Evoked Potentials, Motor ; Evoked Potentials, Somatosensory ; Female ; Humans ; Intracranial Aneurysm ; physiopathology ; surgery ; Male ; Microsurgery ; Middle Aged ; Monitoring, Intraoperative ; Sensitivity and Specificity

Objective To investigate the efficacy of endoscopic Delta large channel unilateral laminotomy for bilateral decompression(ULBD)in the treatment of lumbar spinal stenosis(LSS),and the postoperative complications was analyzed.Methods A total of 100 patients with LSS in our hospital from January 2021 to February 2023 were selected and divided into the control group and the observation group according to random number table method,with 50 cases in each group.Patient in the control group were treated with bilateral or unilateral decompression through the median incision adjacent to the lateral spinous process,and patients in the observation group were treated with endoscopic Delta large channel ULBD.The visual analogue scale(VAS)scores,Japanese Orthopaedic Association(JOA)scores,Oswestry disability index(ODI)scores before surgery and 1 month,3 months,6 months after surgery,as well as clinical efficacy and incidence of postoperative complications of patients between the two groups were compared.Results Compared with preoperative results,the VAS scores of leg pain and low back pain and ODI scores of patients 1 month,3 months and 6 months after surgery in both groups were significantly lower(P<0.05),and JOA scores were significantly higher(P<0.05).Moreover,compared with the control group,the VAS scores of leg pain and low back pain and ODI scores of patients 1 month,3 months and 6 months after surgery in the observation group were lower(P<0.05),the JOA scores were higher(P<0.05).The total effective rate in the observation group was 98.00%,which was higher than 72.00%in the control group(P<0.05).The incidence of postoperative complications in the observation group was 4.00%,which was lower than 24.00%in the control group(P<0.05).Conclusion Endoscopic Delta large channel ULBD in the treatment of LSS can effectively reduce postopera-tive leg pain and low back pain,improve lumbar function,improve clinical therapeutic effect,and reduce postoperative complications.