Postoperative Cognitive Improvement Research Articles

Cerebrovascular dysregulation and postoperative cognitive alterations after carotid endarterectomy.

There are controversial data about the effect of carotid endarterectomy regarding postoperative cognitive function. Our aim was to analyze the effect of cerebral tissue saturation monitored by near-infrared spectroscopy (NIRS) on cognitive function. Perioperative data of 103 asymptomatic patients undergoing elective carotid surgery under general anesthesia were analyzed. Preoperatively and 3months after the operation, MMSE (Mini Mental State Examination) and MoCA (Montreal Cognitive Assessment) tests were conducted. For cerebral monitoring, NIRS was used, and the lowest rSO2 value and the degree of desaturation were calculated. Cognitive changes were defined as one standard deviation change from the preoperative test scores, defined as postoperative neurocognitive decline (PNCD) and cognitive improvement (POCI). PNCD was found in 37 patients (35.92%), and POCI was found in 18 patients (17.47%). Female gender, patients with diabetes, and the degree of desaturation were independently associated with PNCD. The degree of desaturation during the cross-clamp period negatively correlated with the change in the MoCA scores (R = - 0.707, p = 0.001). The 15.5% desaturation ratio had 86.5% sensitivity and 78.8% specificity for discrimination. For POCI, a desaturation of less than 12.65% had 72.2% sensitivity and 67.1% specificity. POCI was associated with lower preoperative MOCA scores and a lower degree of desaturation. We found a significant relation between the change of postoperative cognitive function proven by the MoCA test and cerebral tissue saturation during the clamping period in patients undergoing carotid endarterectomy.

Association between Preoperative Cortical Magnetic Susceptibility and Postoperative Changes in the Cerebral Blood Flow on Cognitive Improvement following Carotid Endarterectomy

Introduction: While patients who experience improved cognition following carotid endarterectomy (CEA) typically demonstrate restored brain perfusion after the procedure, it is worth noting that less than 50% of patients in whom postoperative cerebral blood flow (CBF) restoration is achieved actually show improved cognition after postoperatively. This suggests that factors beyond the mere restoration of CBF may play a role in postoperative cognitive improvement. Increased iron deposition in the cerebral cortex may cause neural damage, and quantitative susceptibility mapping (QSM) obtained using magnetic resonance imaging (MRI) quantifies magnetic susceptibility in the cerebral cortex, allowing for the assessment of iron deposition in vivo. The purpose of the present study was to determine whether preoperative cortical magnetic susceptibility as well as postoperative changes in CBF are associated with cognitive improvement after CEA. Methods: Brain MRI with a three-dimensional gradient echo sequence was preoperatively performed in 53 patients undergoing CEA for ipsilateral internal carotid artery stenosis (≥70%), and QSM with brain surface correction and vein removal was obtained. Cortical magnetic susceptibility was measured in the cerebral hemisphere ipsilateral to surgery on QSM. Preoperatively and at 2 months after the surgery, brain perfusion single-photon emission computed tomography and neuropsychological assessments were conducted. Using these collected data, we evaluated alterations in CBF within the affected hemisphere and assessed cognitive improvements following the operation. Results: A logistic regression analysis showed that a postoperative greater increase in CBF (95% confidence interval [CI], 1.06–1.90; p = 0.0186) and preoperative lower cortical magnetic susceptibility (95% CI, 0.03–0.74; p = 0.0201) were significantly associated with postoperatively improved cognition. Although sensitivity, specificity, and positive and negative predictive values with the cutoff value lying closest to the upper left corner of a receiver operating characteristic curve for the prediction of postoperatively improved cognition did not differ between postoperative changes in CBF and preoperative cortical magnetic susceptibility, the specificity and the positive predictive value were significantly greater for the combination of postoperative changes in CBF and preoperative cortical magnetic susceptibility (specificity, 95% CI, 93–100%; positive predictive value 95% CI, 68–100%) than for the former parameter alone (specificity, 95% CI, 63–88%; positive predictive value 95% CI, 20–64%). Conclusion: Preoperative cortical magnetic susceptibility as well as postoperative changes in CBF are associated with cognitive improvement after CEA.

Increased Parenchymal Free Water May Be Decreased by Revascularization Surgery in Patients with Moyamoya Disease.

Moyamoya disease (MMD) is a cerebrovascular disease associated with steno-occlusive changes in the arteries of the circle of Willis and with hemodynamic impairment. Previous studies have reported that parenchymal extracellular free water levels may be increased and the number of neurites may be decreased in patients with MMD. The aim of the present study was to investigate the postoperative changes in parenchymal free water and neurites and their relationship with cognitive improvement. Multi-shell diffusion MRI (neurite orientation dispersion and density imaging and free water imaging using a bi-tensor model) was performed in 15 hemispheres of 13 adult patients with MMD (11 female, mean age 37.9 years) who had undergone revascularization surgery as well as age- and sex-matched normal controls. Parameter maps of free water and free-water-eliminated neurites were created, and the regional parameter values were compared among controls, patients before surgery, and patients after surgery. The anterior and middle cerebral artery territories of patients showed higher preoperative free water levels (P ≤ 0.007) and lower postoperative free water levels (P ≤ 0.001) than those of normal controls. The change in the dispersion of the white matter in the anterior cerebral artery territory correlated with cognitive improvement (r = -0.75; P = 0.004). Our study suggests that increased parenchymal free water levels decreased after surgery and that postoperative changes in neurite parameters are related to postoperative cognitive improvement in adult patients with MMD. Diffusion analytical methods separately calculating free water and neurites may be useful for unraveling the pathophysiology of chronic ischemia and the postoperative changes that occur after revascularization surgery in this disease population.

Predictive Ability of Frontal Assessment Battery for Cognitive Improvement After Shunt Surgery in Individuals With Idiopathic Normal Pressure Hydrocephalus.

The predictive ability of the Frontal Assessment Battery (FAB) for postoperative cognitive improvement in idiopathic normal pressure hydrocephalus (iNPH) is unstudied. To compare the predictive ability of the FAB and the Mini-Mental State Examination (MMSE) for postoperative cognitive improvement in individuals with iNPH after shunt surgery. We retrospectively reviewed the medical records of individuals with iNPH who had shunt surgery between January 2016 and October 2018. Individuals had completed the tap test and clinical evaluations (FAB, MMSE, Timed Up and Go [TUG]) both before and 24-48 hours after CSF tapping and after surgery. We excluded individuals without complete clinical evaluations and those with shunt surgery performed >6 months after CSF tapping. Factors associated with postoperative FAB and MMSE improvement as per the 2011 iNPH guidelines were extracted using univariate and multivariate logistic regression analyses. Independent variables were baseline FAB and MMSE scores, FAB and MMSE score changes and TUG amelioration rate after CSF tapping, Evans index, age, and days from CSF tapping to surgery and from surgery to postoperative assessment. The mean number of days from CSF tapping to surgery and from surgery to postoperative assessment were 77.5 (SD = 36.0) and 42.0 (SD = 14.5), respectively. Logistic regression analyses showed significant associations in the univariate analyses of postoperative FAB improvement with baseline FAB scores ( P = 0.043) and with FAB score changes after CSF tapping ( P = 0.047). The FAB may help predict postoperative cognitive improvement after shunt surgery better than the MMSE.

Utility of sample entropy from intraoperative cerebral NIRS oximetry data in the diagnosis of postoperative cognitive improvement.

Background: Appropriate monitoring and early recognition of postoperative cognitive improvement (POCI) are essential. Near-infrared spectroscopy (NIRS) showed the predictive potential of POCI. Non-linear dynamical analysis is a powerful approach for understanding intraoperative regional cerebral oxygen saturation (rSO2). Objective: We hypothesized that the sample entropy (SampEn) value of intraoperative rSO2 has the potential to predict POCI. Methods: This retrospective cohort study was conducted from June 2019 and December 2020 in a tertiary hospital in Beijing, China. A total of 126 consecutive patients who underwent carotid endarterectomy (CEA) were screened. 57 patients were included in this analysis. The primary outcome was the diagnostic accuracy of rSO2 for the prediction of POCI. Results: 33 patients (57.9%) developed POCI on postoperative day. The SampEn values of rSO2 were significantly higher in the POCI group (p < 0.05). SampEn remained an independent predictor of POCI in multivariate analysis. The area under the ROC curve (AUC) value of SampEn of rSO2 for POCI were 0.706 (95% CI, 0.569–0.843; p = 0.008). Addition of preoperative MoCA assessment and blood pressure-lowering treatment increased the AUC to 0.808 (95% CI, 0.697–0.919; p < 0.001). Conclusions: The SampEn value of rSO2 showed promise as a predictor of POCI. Non-linear analysis could be used as a supplementary method for intraoperative physiological signals.

Connectomic Profiles and Cognitive Trajectories After Epilepsy Surgery in Children.

Neurocognitive outcomes after surgery for temporal lobe epilepsy in childhood are variable. Postoperative changes are not directly predicted by seizure freedom, and associations between epilepsy, neuropsychological function, and developing neural networks are poorly understood. Here, we leveraged whole-brain connectomic profiling in magnetoencephalography (MEG) to retrospectively study associations between brain connectivity and neuropsychological function in children with temporal lobe epilepsy undergoing resective surgery. Clinical and MEG data were retrospectively analyzed for children who underwent temporal lobe epilepsy surgery at the Hospital for Sick Children from 2000 to 2021. Resting-state connectomes were constructed from neuromagnetic oscillations via the weighted-phase lag index. Using a partial least-squares (PLS) approach, we assessed multidimensional associations between patient connectomes, neuropsychological scores, and clinical covariates. Bootstrap resampling statistics were performed to assess statistical significance. A total of 133 medical records were reviewed, and 5 PLS analyses were performed. Each PLS analysis probed a particular neuropsychological domain and the associations between its baseline and postoperative scores and the connectomic data. In each PLS analysis, a significant latent variable was identified, representing a specific percentage of the variance in the data and relating neural networks to clinical covariates, which included changes in rote verbal memory (n = 41, p = 0.01, σ2 = 0.38), narrative/verbal memory (n = 57, p = 0.00, σ2 = 0.52), visual memory (n = 51, p = 0.00, σ2 = 0.43), working memory (n = 44, p = 0.00, σ2 = 0.52), and overall intellectual function (n = 59, p = 0.00, σ2 = 0.55). Children with more diffuse, bilateral intrinsic connectivity across several frequency bands showed lower scores on all neuropsychological assessments but demonstrated a greater propensity for gains after resective surgery. Here, we report that connectomes characterized by diffuse connectivity, reminiscent of developmentally immature networks, are associated with lower preoperative cognition and postoperative cognitive improvement. These findings provide a potential means to understand neurocognitive function in children with temporal lobe epilepsy and expected changes postoperatively.

Differential Cognitive Functioning and Benefit From Surgery in Patients Undergoing Coronary Artery Bypass Grafting and Carotid Endarterectomy.

BackgroundStenosing atherosclerosis in both coronary and carotid arteries can adversely affect cognition. Also their surgical treatments, coronary artery bypass grafting (CABG) and carotid endarterectomy (CEA), are associated with cognitive changes, but the mechanisms of cognitive decline or improvement may not be the same. This study was designed to compare the cognitive profile and outcome in patients undergoing surgical treatment for coronary or carotid disease.MethodsA total of 100 CABG patients and 44 CEA patients were recruited in two previously reported studies. They were subjected to a comprehensive neuropsychological examination prior to surgery and in the acute (3–8 days) and stable (3 months) phase after operation. A group of 17 matched healthy controls were assessed with similar intervals. We used linear mixed models to compare cognitive trajectories within six functional domains between the CABG, CEA and control groups. Postoperative cognitive dysfunction (POCD) and improvement (POCI) were determined with the reliable change index method in comparison with healthy controls.ResultsBefore surgery, the CEA patients performed worse than CABG patients or healthy controls in the domains of executive functioning and processing speed. The CABG patients exhibited postoperative cognitive dysfunction more often than the CEA patients in most cognitive domains in the acute phase but had regained their performance in the stable phase. The CEA patients showed more marked postoperative improvement in executive functioning than the CABG group in the acute phase, but the difference did not reach significance in the stable phase.ConclusionOur findings suggest that anterior cerebral dysfunction in CEA patients impairs preoperative cognition more severely than global brain dysfunction in CABG patients. However, CEA may have more beneficial effects on cognition than CABG, specifically in executive functions mainly operated by the prefrontal lobes. In addition, the results underline that POCD is a heterogeneous condition and dependent on type of revascularization surgery.

Potential Neuroprotective Role of Sugammadex: A Clinical Study on Cognitive Function Assessment in an Enhanced Recovery After Cardiac Surgery Approach and an Experimental Study.

BackgroundPostoperative cognitive dysfunction affects the quality of recovery, particularly affecting the elderly, and poses a burden on the health system. We hypothesize that the use of sugammadex (SG) could optimize the quality of postoperative cognitive function and overall recovery through a neuroprotective effect.MethodsA pilot observational study on patients undergoing cardiac surgery with enhanced recovery after cardiac surgery (ERACS) approach, was designed to compare SG-treated (n = 14) vs. neostigmine (NG)-treated (n = 7) patients. The Postoperative Quality Recovery Scale (PQRS) was used at different times to evaluate cognitive function and overall recovery of the patients. An online survey among anesthesiologists on SG use was also performed. Additionally, an animal model study was designed to explore the effects of SG on the hippocampus.ResultsSugammadex (SG) was associated with favorable postoperative recovery in cognitive domains particularly 30 days after surgery in patients undergoing aortic valve replacement by cardiopulmonary bypass and the ERACS approach; however, it failed to demonstrate a short-term decrease in length of intensive care unit (ICU) and hospital stay. The survey information indicated a positive appreciation of SG recovery properties. SG reverts postoperative memory deficit and induces the expression of anti-inflammatory microglial markers.ConclusionThe results show a postoperative cognitive improvement by SG treatment in patients undergoing aortic valve replacement procedure by the ERACS approach. Additionally, experimental data from an animal model of mild surgery confirm the cognitive effect of SG and suggest a potential effect over glia cells as an underlying mechanism.

Application of transcutaneous electrical acupoint stimulation in perioperative period

Transcutaneous electrical acupoint stimulation (TEAS) has the characteristics of simple operation, non-invasive, and high patient acceptability, and is widely used in clinical practice. This article summarized the effects of TEAS on analgesia, gastrointestinal tract regulation, circulation regulation, postoperative cognitive function improvement, immune function regulation, anti-inflammatory and anti-stress during the perioperative period. At the same time, this article analyzed the problems of the application of TEAS in the perioperative period, and aimed to promote its clinical application.

Cognitive outcomes following frontal lobe resection for treatment of epilepsy in children and adolescents

ObjectiveTo use reliable change indices (RCIs) developed specifically for pediatric patients with epilepsy to examine cognitive outcomes after frontal lobe resection for pharmacoresistant epilepsy. MethodsForty-one pediatric patients (25 male, Mage = 10 years) completed comprehensive neuropsychological evaluations before and an average of 6.5 months after frontal lobe resections for treatment of epilepsy. Evaluations included tests of intelligence, attention/working memory, processing speed, language, visuospatial skills, executive function, and episodic memory. Practice effect-adjusted RCIs were used to determine clinically significant postoperative cognitive change. Demographic, disease, and surgical variables were examined to identify factors associated with postoperative cognitive decline or improvement. ResultsWithin each cognitive domain, there was a large proportion of patients (51–84%) who did not exhibit significant cognitive change. In terms of overall cognitive profile, 44% demonstrated improvement in at least one domain and 69% declined in at least one domain. Postoperative cognitive improvement occurred most commonly in the domain of processing speed, whereas postoperative cognitive decline occurred most frequently in the domain of visuospatial skills. Younger age at surgery was associated with cognitive improvement. Older age at seizure onset and higher baseline cognitive performance were associated with cognitive decline. SignificanceApproximately 6.5 months after frontal lobe resection, only 15% of our sample showed stable performance across all cognitive domains. Seventeen percent of patients showed improvements without declines, 42% showed declines without improvements, and 27% showed a mix of improvements and declines across different cognitive domains. Age and baseline abilities were associated with postoperative cognitive change on multiple measures. With 1 in 8 children demonstrating postoperative decline across three or more domains, further research is needed to identify factors associated with cognitive decline in order to inform clinical decision-making and patient/family counseling.

Cognitive Dysfunction and Mortality After Carotid Endarterectomy

Background: Carotid endarterectomy (CEA) has been associated with both postoperative cognitive dysfunction (POCD) and improvement (POCI). However, the prognostic significance of postoperative cognitive changes related to CEA is largely unknown. The aim of this study was to examine the associations between postoperative cognitive changes after CEA and long-term survival.Methods: We studied 43 patients 1 day before CEA as well as 4 days and 3 months after surgery with an extensive neuropsychological test array, and followed them for up to 14 years. POCD and POCI relative to baseline were determined with the reliable change index derived from 17 healthy controls. Associations between POCD/POCI and mortality within the patient group were studied with Cox regression analyses adjusted for confounders.Results: POCD in any functional domain was evident in 28% of patients 4 days after surgery and in 33% of patients 3 months after surgery. POCI was shown in 23% of patients at 4 days and in 44% of patients at 3 months. POCD at 3 months was associated with higher long-term mortality (hazard ratio 5.0, 95% CI 1.8–13.9, p = 0.002) compared with patients with no cognitive decline.Conclusions: Our findings suggest that POCD in a stable phase, 3 months after CEA predicts premature death. Evaluation of postoperative cognitive changes is essential, and POCD in a stable phase after CEA should prompt scrutiny of underlying factors and better adherence to therapies to prevent recurrences and to promote early intervention in imminent deterioration.

High frequency oscillations relate to cognitive improvement after epilepsy surgery in children

ObjectiveTo investigate how high frequency oscillations (HFOs; ripples 80–250 Hz, fast ripples (FRs) 250–500 Hz) and spikes in intra-operative electrocorticography (ioECoG) relate to cognitive outcome after epilepsy surgery in children. MethodsWe retrospectively included 20 children who were seizure free after epilepsy surgery using ioECoG and determined their intelligence quotients (IQ) pre- and two years postoperatively. We analyzed whether the number of HFOs and spikes in pre- and postresection ioECoGs, and their change in the non-resected areas relate to cognitive improvement (with ≥ 5 IQ points increase considered to be clinically relevant (=IQ+ group) and < 5 IQ points as irrelevant (=IQ− group)). ResultsThe IQ+ group showed significantly more FRs in the resected tissue (p = 0.01) and less FRs in the postresection ioECoG (p = 0.045) compared to the IQ− group. Postresection decrease of ripples on spikes was correlated with postoperative cognitive improvement (correlation coefficient = −0.62 with p = 0.01). ConclusionsPostoperative cognitive improvement was related to reduction of pathological HFOs signified by removing FR generating areas with subsequently less residual FRs, and decrease of ripples on spikes in the resection edge of the non-resected area. SignificanceHFOs recorded in ioECoG could play a role as biomarkers in the prediction and understanding of cognitive outcome after epilepsy surgery.

Postoperative change of neuropsychological function after indirect revascularization in childhood moyamoya disease: a correlation with cerebral perfusion study.

The relationships between postoperative functional improvement in various cognitive domains and regional hemodynamic change have not been sufficiently studied in childhood moyamoya disease (MMD). The present study aimed to examine the cognitive benefit of indirect revascularization, the underlying biological mechanism, and factors affecting surgical outcome in childhood MMD. Twenty-three patients with MMD aged under 20years received neuropsychological examinations before and after indirect revascularization surgery, evaluating intellectual function, verbal and visual memory, and executive function. Among them, 13 patients had magnetic resonance perfusion (MRP) studies, in which regional cerebral perfusion was rated. Postoperative improvement was observed in verbal memory performances (p = 0.02-0.03) and in cerebral perfusion at all 26 cerebral hemispheres (p = 0.003-0.005), especially in the middle cerebral artery (MCA) territories (p = 0.001-0.003). Hemodynamic improvement in the left MCA territories was significantly correlated with improvement of both verbal new learning (p = 0.01) and intellectual function (p = 0.004). Postoperative cognitive improvement of immediate recall and verbal intellectual function was associated with female sex (r = - 0.42) and symptom duration (p = - 0.03), respectively. Hemodynamic improvement in the MCA territories was related to longer follow-up intervals (p = 0.02). The findings revealed that the selective postoperative cognitive improvement was associated with increased regional perfusion in the MCA territories, and indicate the importance of early intervention and the potential of indirect revascularization regarding long-term outcome.

Impact of cerebral blood flow changes due to arterial bypass surgery on cognitive function in adult patients with symptomatic ischemic moyamoya disease.

Some adult patients with moyamoya disease (MMD) undergoing revascularization surgery show an improvement or decline in cognition postoperatively. Revascularization surgery for ischemic MMD augments cerebral blood flow (CBF) and improves cerebral oxygen metabolism. However, cerebral hyperperfusion, which is a short-term, major increase in ipsilateral CBF that is much greater than the metabolic needs of the brain, sometimes occurs as a complication. Cerebral hyperperfusion produces widespread, minimal injury to the ipsilateral white matter and cortical regions. The aim of the present prospective study was to determine how changes in CBF due to arterial bypass surgery affect cognitive function in adult patients with symptomatic ischemic MMD and misery perfusion. Thirty-two patients with cerebral misery perfusion, as determined on the basis of 15O gas positron emission tomography, underwent single superficial temporal artery-middle cerebral artery (M4 in the precentral region) anastomosis. Brain perfusion single-photon emission computed tomography (SPECT) studies were performed preoperatively, on the 1st postoperative day, and 2 months after surgery. Neuropsychological tests were also performed preoperatively and 2 months after surgery. Postoperative neuropsychological assessments demonstrated cognitive improvement in 10 cases (31%), no change in 8 cases (25%), and decline in 14 cases (44%). Based on brain perfusion SPECT and symptoms, 10 patients were considered to have cerebral hyperperfusion syndrome, and all of these patients exhibited a postoperative decline in cognition. Relative precentral CBF on the 1st postoperative day was significantly greater in patients with postoperative cognitive decline (167.3% ± 15.3%) than in those with improved (105.3% ± 18.2%; p < 0.0001) or unchanged (131.4% ± 32.1%; p = 0.0029) cognition. The difference between relative precentral CBF 2 months after surgery and that before surgery was significantly greater in patients with postoperative cognitive improvement (17.2% ± 3.8%) than in those with no postoperative change (10.1% ± 2.4%; p = 0.0003) or with postoperative decline (11.5% ± 3.2%; p = 0.0009) in cognition. Cerebral hyperperfusion in the acute stage after arterial bypass surgery impairs cognitive function. An increase in CBF in the chronic stage without acute-stage cerebral hyperperfusion improves cognitive function in adult patients with symptomatic ischemic MMD and misery perfusion.

Seizure and cognitive outcomes of posterior quadrantic disconnection: a series of 12 pediatric patients

Purpose: To evaluate surgical outcomes and cognitive improvements after posterior quadrantic disconnection (PQD) in children who had medically intractable epilepsy and to compare the various characteristics between the acquired group and the developmental group.Method: Between 2015 and 2017, we retrospectively enrolled all pediatric patients who underwent PQD. We used image post-processing techniques for preoperative evaluation. Seizure outcomes and postoperative cognitive improvements were analysed. The patients were divided into the acquired group and the developmental group depending on the pathology; we then compared groups regarding age at onset, surgery, history, and seizure and cognitive outcomes.Results: A total of 12 pediatric patients were enrolled, including 7 acquired patients and 5 developmental patients. After a median 28.9-month follow-up, 11 (91.7%) of 12 patients were seizure free. The image post-processing facilitated a better visualization on preoperative evaluation and helped with detection of the epileptogenic zone. There were significant linear relationships between improvements in IQ and operative age (R2=0.527, p = 0.007) and IQ and epileptic history (R2=0.696, p = 0.001). The median age at seizure onset was 4.86 ± 2.12 years in the acquired group and 2.40 ± 1.14 years in the developmental group (t = 2.344, p = 0.028). Epileptic histories, seizure outcomes and cognitive outcomes were not significantly different between groups.Conclusion: Posterior quadrantic disconnection is an effective epilepsy surgery in selected patients. The use of image post-processing is important for preoperative evaluation. The age at seizure onset and surgery in malformation of cortical development (MCD) patients was earlier; however, the seizure outcome was no better than in acquired pathology patients. Early surgery did not change seizure outcomes but improved cognition.

Parents' view of the cognitive outcome one year after pediatric epilepsy surgery

ObjectivesThe cognitive outcome of pediatric epilepsy surgery has mainly been examined on the basis of standardized tests. Here, we analyzed the outcome in six cognitive domains from the parents' view. MethodsIncluded were consecutive surgical pediatric patients whose parents filled-in a comprehensive questionnaire on cognitive problems in children and adolescents (Kognitive Probleme bei Kindern und Jugendlichen (KOPKIJ); Gleissner et al. 2006) at the preoperative baseline (T1) as well as twelve months thereafter (T2). All children also underwent standard neuropsychological assessments at T1 and T2. ResultsParents of 96 patients provided pre- and postoperative KOPKIJ data. Overall, 80% of the children became seizure-free at the follow-up. Group means indicated a strong positive effect of time on KOPKIJ and neuropsychological performance. We found postoperative improvements in five out of six cognitive domains (language, memory, executive functions, attention, school; unchanged: visuospatial abilities). Individually, improvements were twice as likely as declines. However, 33 patients (35%) experienced significant decline in at least one cognitive domain. Later onset of epilepsy resulted in better performance but had no effect on change scores. Seizure-free status, lower antiseizure drug load, and stronger drug reduction after surgery contributed to postoperative cognitive improvements as perceived by the parents; no other effects of clinical factors were obtained (e.g., localization/lateralization). Despite their similar outcome patterns, change scores as derived from parental ratings and neuropsychological assessment were not correlated. ConclusionsParents acknowledged the overall positive neurocognitive development after pediatric epilepsy surgery as previously shown by standardized tests. Seizure freedom and lower antiseizure drug load contributed to the beneficial cognitive outcome. Even if cognitive improvements outweighed declines, a risk for cognitive decline with impact on everyday functioning does exist.

Predicting Cognitive Improvement in Normal Pressure Hydrocephalus Patients Using Preoperative Neuropsychological Testing and Cerebrospinal Fluid Biomarkers.

Though it is well known that normal pressure hydrocephalus (NPH) patients can cognitively improve after ventriculoperitoneal shunting (VPS), one of the major dilemmas in NPH is the ability to prospectively predict which patients will improve. To prospectively assess preoperative predictors of postshunt cognitive improvement. This was a prospective observational cohort including 52 consecutive patients with approximately 1-yr follow-up. Patients underwent neuropsychological testing at baseline, postlumbar drainage, and postshunt. Cerebrospinal fluid (CSF) biomarkers and cortical biopsies were also collected to examine their relationship with postshunt cognitive improvement. Rey Auditory Verbal Learning Test-L (RAVLT-L) was the only neuropsychological test to demonstrate statistically significant improvement both postlumbar drain and postshunt. Improvement on the RAVLT-L postlumbar drain predicted improvement on the RAVLT-L postshunt. Patients with biopsies demonstrating Aβ+Tau+had lower ventricular CSF Aβ42 and higher lumbar CSF pTau compared to Aβ- Tau- patients. A receiver operating curve analysis using lumbar pTau predicted Aβ+Tau+biopsy status but was not related to neuropsychological test outcome. The RAVLT can be a useful preoperative predictor of postoperative cognitive improvement, and thus, we recommend using the RAVLT to evaluate NPH patients. CSF biomarkers could not be related to neuropsychological test outcome. Future research in a larger patient sample will help determine the prospective utility of CSF biomarkers in the evaluation of NPH patients.

Predictors of cognitive function in patients with hypothalamic hamartoma following stereotactic radiofrequency thermocoagulation surgery.

To determine the predictors of cognitive function in patients with drug-resistant gelastic seizures (GS) related to hypothalamic hamartoma (HH) before and after stereotactic radiofrequency thermocoagulation surgery (SRT). We studied 88 patients with HH who underwent SRT between October 1997 and December 2014. Patients received neuropsychological tests preoperatively and postoperatively. Based on the preoperative measures, patients were categorized as "high-functioning" (full-scale intelligence quotient [FSIQ] ≥70; n = 48) and "low-functioning" group (FSIQ <70; n = 40). Univariate and multivariate linear regression analyses determined the clinical, electroencephalography (EEG), and imaging factors associated with preoperative cognitive function as well as postoperative cognitive change. Eighty-seven patients (98.8%) were followed postoperatively for an average of 3.3 years, and 75 (85.2%) of them achieved GS remission at the last hospital visit. Neuropsychological performance was significantly improved after surgery in both groups. Multivariate linear regression analysis showed that a smaller HH size (p = 0.002) and a smaller number of antiepileptic drugs (p < 0.001) were preoperatively associated with better neuropsychological performance. Multivariate linear regression analysis showed that better postoperative improvement in cognition was associated with a shorter duration of epilepsy (p = 0.03). Cognitive impairment related to epileptic encephalopathy may improve following SRT in substantial proportions of HH patients. Reduced improvement in postoperative cognitive function in patients with longer duration of epilepsy warrants further studies to determine if earlier SRT provides a greater chance of postoperative cognitive improvement in patients with HH.

Liver Fibrosis Predicts Cognitive Function Following Bariatric Surgery: A Preliminary Investigation

Obesity is a well-established risk factor for poor neurological outcomes, and bariatric surgery has been shown to improve many aspects of cognitive function. Factors underlying improved cognition following surgery are not yet fully established. A recent study of bariatric surgery patients demonstrated lower preoperative alkaline phosphatase concentrations were linked to greater postoperative cognitive improvement, but this link has not been examined via liver biopsy. The current study examined postoperative cognitive function in individuals with and without fibrosis at the time of bariatric surgery. It expected that those with fibrosis would demonstrate poorer postoperative cognition. Thirty-six bariatric surgery patients underwent routine liver biopsy at the time of surgery and completed cognitive testing 1 month postoperatively. Bariatric surgery patients with fibrosis demonstrated poorer performance on a task of executive function (maze errors, P = 0.01) and verbal memory (recognition memory, P = 0.01). Bariatric surgery patients with fibrosis demonstrated poorer cognition following surgery, providing further evidence for the connection between liver disease and cognitive function. Future work examining mechanisms underlying bariatric postoperative cognitive changes should include examination of broader metabolic functions, particularly liver function.

The Association Between Reduced Inflammation and Cognitive Gains After Bariatric Surgery.

Bariatric surgery is associated with improved cognitive function, although the mechanisms are unclear. Elevated inflammation is common in obesity and associated with impaired cognition. Inflammation decreases after bariatric surgery, implicating it as a possible mechanism for cognitive improvement. The objective of this study was to examine whether reduced inflammation is a possible mechanism for postoperative cognitive improvement in bariatric surgery patients. Participants were 77 bariatric surgery patients who completed cognitive testing before surgery and 1 year postsurgery. Cognitive domains assessed were attention/executive function, language, and memory. High-sensitivity C-reactive protein (CRP) was assessed at both time points. Patients exhibited preoperative cognitive impairment, although improvements 1 year postsurgery were seen in both attention/executive function (mean [M; standard deviation {SD}]baseline = 53.57 [8.68] versus M (SD)follow-up= 60.32 [8.19]) and memory (M [SD]baseline= 44.96 [7.98] versus M [SD]follow-up= 51.55 [8.25]). CRP was elevated at baseline and fell into the normative range postsurgery (M [SD]baseline= 0.9 [0.7] versus M [SD]follow-up= 0.2 [0.3] mg/dl). Preoperative CRP was not associated with baseline cognitive function (β values = -0.10 to 0.02) and changes in CRP also did not correspond to changes in cognition postsurgery (β values = 0.02-0.11; p values > .05 for all domains). A trend was detected for smaller improvements in memory among participants with elevated baseline CRP (>0.30 mg/dl) versus those with normal levels (group × time: p = .083). Improvements in high-sensitivity CRP were not associated with postoperative cognitive benefits. Future studies are needed to explore other inflammatory markers and potential mechanisms of cognitive improvement after bariatric surgery, including improved glycemic control and neurohormone changes.