Clinical characteristics and outcomes of aortic prosthetic valve endocarditis: comparison between transcatheter and surgical bioprostheses.

PURPOSE: Most data regarding infective endocarditis (IE) after transcatheter aortic valve implantation (TAVI) comes from TAVI registries, rather than IE dedicated cohorts. The objective of our study was to compare the clinical and microbiological profile, imaging features and outcomes of patients with IE after SAVR with a biological prosthetic valve (IE-SAVR) and IE after TAVI (IE-TAVI) from 6 centres with an Endocarditis Team (ET) and broad experience in IE. METHODS: Retrospective analysis of prospectively collected data. From the time of first TAVI implantation in each centre to March 2021, all consecutive patients admitted for IE-SAVR or IE-TAVI were prospectively enrolled. Follow-up was monitored during admission and at 12 months after discharge. RESULTS: 169 patients with IE-SAVR and 41 with IE-TAVI were analysed. Early episodes were more frequent among IE-TAVI. Clinical course during hospitalization was similar in both groups, except for a higher incidence of atrioventricular block in IE-SAVR. The most frequently causative microorganisms were S. epidermidis, Enterococcus spp. and S. aureus in both groups. Periannular complications were more frequent in IE-SAVR. Cardiac surgery was performed in 53.6% of IE-SAVR and 7.3% of IE-TAVI (p=0.001), despite up to 54.8% of IE-TAVI patients had an indication. No differences were observed about death during hospitalization (32.7% vs 35.0%), and at 1-year follow-up (41.8% vs 37.5%), regardless of whether the patient underwent surgery or not. CONCLUSION: Patients with IE-TAVI had a higher incidence of early prosthetic valve IE. Compared to IE-SAVR, IE-TAVI patients underwent cardiac surgery much less frequently, despite having surgical indications. However, in-hospital and 1-year mortality rate was similar between both groups.

Neuronal and astrocytic tetraploidy is increased in drug-resistant epilepsy.

AIMS: Epilepsy is one of the most prevalent neurological diseases. A third of patients with epilepsy remain drug-resistant. The exact aetiology of drug-resistant epilepsy (DRE) is still unknown. Neuronal tetraploidy has been associated with neuropathology. The aim of this study was to assess the presence of tetraploid neurons and astrocytes in DRE. METHODS: For that purpose, cortex, hippocampus and amygdala samples were obtained from patients subjected to surgical resection of the epileptogenic zone. Post-mortem brain tissue of subjects without previous records of neurological, neurodegenerative or psychiatric diseases was used as control. RESULTS: The percentage of tetraploid cells was measured by immunostaining of neurons (NeuN) or astrocytes (S100ß) followed by flow cytometry analysis. The results were confirmed by image cytometry (ImageStream X Amnis System Cytometer) and with an alternative astrocyte biomarker (NDRG2). Statistical comparison was performed using univariate tests. A total of 22 patients and 10 controls were included. Tetraploid neurons and astrocytes were found both in healthy individuals and DRE patients in the three brain areas analysed: cortex, hippocampus and amygdala. DRE patients presented a higher number of tetraploid neurons (p = 0.020) and astrocytes (p = 0.002) in the hippocampus than controls. These results were validated by image cytometry. CONCLUSIONS: We demonstrated the presence of both tetraploid neurons and astrocytes in healthy subjects as well as increased levels of both cell populations in DRE patients. Herein, we describe for the first time the presence of tetraploid astrocytes in healthy subjects. Furthermore, these results provide new insights into epilepsy, opening new avenues for future treatment.

Intraoperative Cortico-Cortical Evoked Potentials for Monitoring Language Function during Brain Tumor Resection in Anesthetized Patients.

BACKGROUND: Cortico-cortical evoked potentials (CCEPs) have been used to map the frontal (FLA) and parietal (PLA) cortical regions related to language function. However, they have usually been employed as a complementary method during sleep-awake surgery. METHODS: Five male and two female patients received surgery for tumors located near language areas. Six patients received general anesthesia and the sleep-awake method was used for patients with tumors located near the cortical language areas. We performed motor and somatosensory mapping with CCEPs to identify language areas and we monitored responses during surgery based on the mapping results. Electrocorticography was performed throughout the surgery. Single pulses of 1 ms duration at 5-20 mA were delivered by direct cortical stimulation using one grid at one region (e.g., FLA) and then recording using a second gird at another area (i.e., PLA). Next, reversed stimulation (from PLA to FLA) was performed. The charge density for electrical stimulation was computed. Sensibility, specificity, predictive positive values, and predicted negative values were also computed for warning alterations of CCEPs. RESULTS: Gross tumor resection was achieved in four cases. The first postsurgical day showed language alterations in three patients, but one year later six patients remained asymptomatic and one patient showed the same symptomatology as previously. Seizures were observed in two patients that were easily jugulated. CCEPs predicted warning events with high sensibility and specificity. Postsurgical language deficits were mostly transitory. Although the latency between frontal and parietal regions showed symmetry, the amplitude and the relationship between amplitude and latency were different for FLA than for PLA. The charge density elicited by CCEPs ranged from 442 to 1768 µC/cm2. CONCLUSIONS: CCEPs have proven to be a reliable neurophysiological technique for mapping and monitoring the regions associated with language function in a small group of anesthetized patients. The high correlation between warning events and postsurgical outcomes suggested a high sensitivity and specificity and CCEPs can be used systematically in patients under general anesthesia. Nevertheless, the small number of studied patients suggests considering these results cautiously.

Image guidance in transdiscal fixation for high-grade spondylolisthesis in adults with correct spinal balance.

OBJECTIVE Spondylolisthesis is a prevalent spine disease that recent studies estimate could be detected in 9% of the population. High-grade spondylolisthesis (HGS), however, is much less frequent, which makes it difficult to develop a general recommendation for its treatment. Posterior transdiscal fixation was proposed in 1994 for HGS, and the use of spine navigation could make this technique more accessible and reduce the morbidity associated with the procedure. The purpose of this study was to present a case series involving adult patients with HGS and correct spinal alignment who were treated with transdiscal pedicle screw placement guided with neuronavigation and compare the results to those achieved previously without image guidance. METHODS The authors reviewed all cases in which adult patients with correct spinal alignment were treated for HGS with posterior transdiscal instrumentation placement guided with navigation between 2014 and 2016 at their institution. The authors compared preoperative and postoperative spinopelvic parameters on standing radiographs as well as Oswestry Disability Index (ODI) scores and visual analog scale (VAS) scores for low-back pain. Follow-up CT and MRI studies and postoperative radiographs were evaluated to identify any screw malplacement or instrumentation failure. Any other intraoperative or postoperative complications were also recorded. RESULTS Eight patients underwent posterior transdiscal navigated instrumentation placement during this period, with a mean duration of follow-up of 16 months (range 9-24 months). Six of the patients presented with Meyerding grade III spondylolisthesis and 2 with Meyerding grade IV. In 5 cases, L4-S1 instrumentation was placed, while in the other 3 cases, surgery consisted of transdiscal L5-S1 fixation. There was no significant difference between preoperative and postoperative spinopelvic parameters. However, there was a statistically significant improvement in the mean VAS score for low-back pain (6.5 ± 1.5 vs 4 ± 1.7) and the mean ODI score (49.2 ± 19.4 vs 37.7 ± 22) (p = 0.01 and p = 0.012, respectively). Six patients reduced their use of pain medication. There were no intraoperative or postoperative complications during the hospital stay, and as of the most recent follow-up, no complications related to pseudarthrosis or hardware failure had been observed. CONCLUSIONS Treatment with posterior transdiscal pedicle screws with in situ fusion achieved good clinical and radiological outcomes in patients with HGS and good sagittal spinal balance. The use of navigation and image guidance was associated with improved results in this technique, including a reduction in postoperative and intraoperative complications related to screw malplacement, pseudarthrosis, and instrumentation failure.

Clinical Profile and Prognosis of Patients with Left-Sided Infective Endocarditis with Surgical Indication Who Are Not Operated.

Approximately a quarter of patients with infective endocarditis (IE) who have surgical indication only receive antibiotic treatment. Their short-term prognosis is dismal. We aimed to describe the characteristics of this group of patients to evaluate the mortality according to the cause of rejection and type of surgical indication and to analyze their prognostic factors of mortality. From 2005 to 2022, 1105 patients with definite left-sided IE were consecutively attended in three tertiary hospitals. Of them, 912 (82.5%) had formal surgical indication according to the most recent European Guidelines available in each period of the study and 303 (33%) only received medical treatment. These were older, had more comorbidities and higher in-hospital (46% vs. 24%; p < 0.001) and one year mortality (57.1% vs. 27.6%; p < 0.001) than operated patients. The main reason for surgical rejection was high surgical risk (57.1%) and the highest mortality when the cause were severe neurological conditions (76%). When the endocarditis team took the decision not to operate (25.5% of the patients), in-hospital (7%) and one-year mortality (17%) were low. In-hospital mortality associated with each surgical indication was 67% in heart failure, 53% in uncontrolled infection and 45% in prevention of embolisms (p < 0.001). Heart failure (OR: 2.26 CI95%: 1.29-3.96; p = 0.005), Staphylococcus aureus (OR: 3.17; CI95%: 1.72-5.86; p < 0.001) and persistent infection (OR: 5.07 CI95%: 2.85-9.03) are the independent risk factors of in-hospital mortality. One third of the patients with left-sided IE and formal surgical indication are rejected for surgery. In-hospital mortality is very high, especially when heart failure is the indication for surgery and when severe neurological conditions the reason for rejection. Short term prognosis of patients rejected by a specialized endocarditis team is favorable.

Role of intraoperative neurophysiological monitoring during fluorescence-guided resection surgery.

BACKGROUND: Fluorescence-guided resection (FGR) using 5-aminolevulinic acid (5-ALA) exhibits a potential risk of permanent neurological deficits that can be minimized using intraoperative neurophysiological monitoring (IONM). We assessed the role of IONM in FGR surgery in patients harboring tumors in or near eloquent areas. METHODS: IONM and FGR surgeries were performed on 34 patients (49.8 ± 2.4 years) harbored malignant primary gliomas near eloquent cortical areas or semioval center. Different combinations of neurophysiological techniques were used depending on each patient. RESULTS: Gross total resection (GTR) was achieved in 66.7 % of the patients, mean 90.4 ± 3.7 % without neurological deficits. Resection in four patients was stopped by the occurrence of severe warning criteria despite the presence of fluorescence. Hemispheric transcranial electrical stimulation was safe and confident even in cortical surgery. Notably, a significant percentage of patients exhibited clinical improvement after the surgery. One week after surgery, only one patient worsened, and seven patients improved. At 3 months, 27.8 % of the patients improved, and the other patients maintained a similar status to their pre-surgery condition. Warning common criteria (amplitude reduction and/or latency increase) appeared in 68.2 and 50.0 % of patients during cortical or semioval surgery, respectively, with neither a false-negative nor a false-positive clinical outcome. Although 5-ALA exhibits phototoxicity, VEP did not induce any secondary effects in the visual system, including eyelids. CONCLUSIONS: IONM can be helpful during surgery to maximize the tumor resection, meanwhile help to avoid neurological deficits and, therefore, to improve the quality of life of these patients.

Measurement of vegetations in infective endocarditis: An inaccurate method to decide the therapeutical approach.

BACKGROUND: The European Society of Cardiology and American Heart Association guidelines give a central role to the maximal vegetation diameter in the indication for surgery to prevent embolism in left sided infective endocarditis. Vegetation measuring is likely to be inaccurate. The hypothesis herein, is that the vegetation diameter is not an appropriate surgical criterion given the variability of its measurement. METHODS: Two trained echocardiographers independently measured the maximal vegetation diameter by transesophageal echocardiogram of 76 vegetations in 67 consecutive patients with definite infective endocarditis in an off-line workstation. The interobserver variability was calculated by the interclass correlation coefficient. The relationship between the strength of agreement for the cut-off points of 10 and 15 mm was also calculated. Finally, the number of patients whose surgical indication would have changed depending on which operator measured the vegetation was evaluated. RESULTS: Interobserver interclass correlation coefficient in the measurement of the maximal longitudinal diameter of the vegetations was 0.757 (0.642-0.839). The strength of agreement of the interobserver analysis for the cut-off point of 10 mm was 0.533 (0.327-0.759). For the cut-off point of 15 mm it was 0.475 (0.270-0.679). If heart failure or uncontrolled infections had been absent, the surgical indication would have changed in a total of 33 patients (33/76; 43%) depending on which operator measured the vegetation. CONCLUSIONS: The variability in the measurements of the maximal longitudinal diameter by transesophageal echocardiogram is high. Surgical indications based on the cut-off points recommended by the international guidelines should be revised.

Contemporary Clinical Profile of Left-Sided Native Valve Infective Endocarditis: Influence of the Causative Microorganism.

Studies focused on the clinical profile of native valve endocarditis are scarce and outdated. In addition, none of them analyzed differences depending on the causative microorganism. Our objectives are to describe the clinical profile at admission of patients with left-sided native valve infective endocarditis in a contemporary wide series of patients and to compare them among the most frequent etiologies. To do so, we conducted a prospective, observational cohort study including 569 patients with native left-sided endocarditis enrolled from 2006 to 2019. We describe the modes of presentation and the symptoms and signs at admission of these patients and compare them among the five more frequent microbiological etiologies. Coagulase-negative Staphylococci and Enterococci endocarditis patients were the oldest (71 ± 11 years), and episodes caused by Streptococci viridans were less frequently nosocomial (4%). The neurologic, cutaneous or renal modes of presentation were more typical in Staphylococcus aureus endocarditis (28%, p = 0.002), the wasting syndrome of Streptococcus viridans (49%, p < 0.001), and the cardiac in Coagulase-negative Staphylococci, Enterococci and unidentified microorganism endocarditis (45%, 49% and 56%, p < 0.001). The clinical signs agreed with the mode of presentation. In conclusion, the modes of presentation and the clinical picture at admission were tightly associated with the causative microorganism in patients with left-sided native valve endocarditis.

DNA Methylation Description of Hippocampus, Cortex, Amygdala, and Blood of Drug-Resistant Temporal Lobe Epilepsy.

Epigenetic changes such as DNA methylation were observed in drug-resistant temporal lobe epilepsy (DR-TLE), a disease that affects 25-30% of epilepsy patients. The main objective is to simultaneously describe DNA methylation patterns associated with DR-TLE in hippocampus, amygdala, surrounding cortex to the epileptogenic zone (SCEZ), and peripheral blood. An Illumina Infinium MethylationEPIC BeadChip array was performed in 19 DR-TLE patients and 10 postmortem non-epileptic controls. Overall, 32, 59, and 3210 differentially methylated probes (DMPs) were associated with DR-TLE in the hippocampus, amygdala, and SCEZ, respectively. These DMP-affected genes were involved in neurotrophic and calcium signaling in the hippocampus and voltage-gated channels in SCEZ, among others. One of the hippocampus DMPs (cg26834418 (CHORDC1)) showed a strong blood-brain correlation with BECon and IMAGE-CpG, suggesting that it could be a potential surrogate peripheral biomarker of DR-TLE. Moreover, in three of the top SCEZ's DMPs (SHANK3, SBF1, and MCF2L), methylation status was verified with methylation-specific qPCR. The differentially methylated CpGs were classified in DMRs: 2 in the hippocampus, 12 in the amygdala, and 531 in the SCEZ. We identified genes that had not been associated to DR-TLE so far such as TBX5, EXOC7, and WRHN. The area with more DMPs associated with DR-TLE was the SCEZ, some of them related to voltage-gated channels. The DMPs found in the amygdala were involved in inflammatory processes. We also found a potential surrogate peripheral biomarker of DR-TLE. Thus, these results provide new insights into epigenetic modifications involved in DR-TLE.

Neurosurgical Treatment of Pain.

The aim of this review is to draw attention to neurosurgical approaches for treating chronic and opioid-resistant pain. In a first chapter, an up-to-date overview of the main pathophysiological mechanisms of pain has been carried out, with special emphasis on the details in which the surgical treatment is based. In a second part, the principal indications and results of different surgical approaches are reviewed. Cordotomy, Myelotomy, DREZ lesions, Trigeminal Nucleotomy, Mesencephalotomy, and Cingulotomy are revisited. Ablative procedures have a limited role in the management of chronic non-cancer pain, but they continues to help patients with refractory cancer-related pain. Another ablation lesion has been named and excluded, due to lack of current relevance. Peripheral Nerve, Spine Cord, and the principal possibilities of Deep Brain and Motor Cortex Stimulation are also revisited. Regarding electrical neuromodulation, patient selection remains a challenge.

Reassessment of Vegetation Size as a Sole Indication for Surgery in Left-Sided Infective Endocarditis.

BACKGROUND: Guidelines recommend surgery for left-sided infective endocarditis (LSIE) that is associated with large vegetations. Given that most patients who undergo surgery also have other indications (heart failure and/or uncontrolled infection), it is not settled whether surgery should be routinely recommended in patients with large vegetations but no other predictors of poor outcome. METHODS: A total of 726 patients with definitive LSIE were included in our analysis. The mean age was 64.9 years, and 61% were male. Multivariate analysis of all patients was performed to determine whether vegetation size is related to death in LSIE. Then patients were divided into two groups according to vegetation size: group A (>10 mm, n = 420) and group B (≤10 mm, n = 306). Univariate and multivariate analyses of group A patients were carried out to identify the variables related to death in this group. The impact of surgery on mortality in group A patients without heart failure or uncontrolled local infection (n = 139) was assessed. RESULTS: Age, Staphylococcus aureus, perivalvular complications, heart failure, kidney failure, and septic shock, but not vegetation size, were associated with death. Patients with large vegetations showed increased mortality (31.7% in group A vs 24.8% in group B; P = .045). Group A had more valve rupture and valve regurgitation than group B, but heart failure (55% vs 53%; P = .678), stroke (22% vs 17.0%, P = .091), systemic embolism (39% vs 32%; P = .074), perivalvular complication (28% vs 28%; P = .865), and septic shock (15% vs 13%; P = .288) were similar in both groups. In patients from group A without heart failure or uncontrolled infection, mortality was similar with and without surgery (n = 139; n = 70 with surgery and n = 69 without surgery; mortality, 18.6% vs 11.6%, respectively; P = .251). CONCLUSIONS: Large vegetations identify patients with poor outcomes in the context of LSIE. However, surgery is not associated with a better prognosis in patients with large vegetations if they do not present with another predictor of poor outcome such as heart failure or uncontrolled infection. These findings challenge whether vegetation size alone should be an indication for surgery in LSIE.

Simulation with 3D Neuronavigation for Learning Cortical Bone Trajectory Screw Placement.

BACKGROUND AND OBJECTIVE: Learning a new technique in neurosurgery is a big challenge especially for trainees. In recent years, simulations and simulators got into the focus as a teaching tool. Our objective is to propose a simulator for placement of cortical bone trajectory (CBT) screws to improve results and reduce complications. METHODS: We have created a platform consisting of a sawbone navigated with a 3D fluoroscope to familiarize our trainees and consultants with CBT technique and later implement it in our department. Objective Structured Assessment of Technical Skills (OSATS) and Physician Performance Diagnostic Inventory Scale (PPDI) were obtained before and after the use of the simulator by the five participants in the study. Patients who were operated on after the implementation of the technique were retrospectively reviewed. RESULTS: During the simulation, there were 4 cases of pedicle breach out of 24 screws inserted (16.6%). After having completed simulation, participants demonstrated an improvement in OSATS and PPDI (p = 0.039 and 0.042, respectively). Analyzing the answers to the different items of the tests, participants mainly improved in the knowledge (p = 0.038), the performance (p = 0.041), and understanding of the procedure (p = 0.034). In our retrospective series, eight patients with L4-L5 instability were operated on using CBT, improving their Oswestry Disability Index (ODI) score (preoperative ODI 58.5 [SD 16.7] vs. postoperative ODI 31 [SD 13.4]; p = 0.028). One intraoperative complication due to a dural tear was observed. In the follow-up, we found a case of pseudoarthrosis and a facet joint violation, but no other complications related to misplacement, pedicle fracture, or hardware failure. CONCLUSION: The simulation we have created is useful for the implementation of CBT. In our study, consultants and trainees have valued very positively the learning obtained using the system. Moreover, simulation facilitated the learning of the technique and the understanding of surgical anatomy. We hope that simulation helps reducing complications in the future.

Prognostic impact of cardiac surgery in left-sided infective endocarditis according to risk profile.

OBJECTIVE: To evaluate the prognostic impact of urgent cardiac surgery on the prognosis of left-sided infective endocarditis (LSIE) and its relationship to the basal risk of the patient and to the surgical indication. METHODS: 605 patients with LSIE and formal surgical indication were consecutively recruited between 2000 and 2020 among three tertiary centres: 405 underwent surgery during the active phase of the disease and 200 did not despite having indication. The prognostic impact of urgent surgery was evaluated by multivariable analysis and propensity score analysis. We studied the benefit of surgery according to baseline mortality risk defined by the ENDOVAL score and according to surgical indication. RESULTS: Surgery is an independent predictor of survival in LSIE with surgical indication both by multivariable analysis (OR 0.260, 95% CI 0.162 to 0.416) and propensity score (mortality 40% vs 66%, p<0.001). Its greatest prognostic benefit is seen in patients at highest risk (predicted mortality 80%-100%: OR 0.08, 95% CI 0.021 to 0.299). The benefit of surgery is especially remarkable for uncontrolled infection indication (OR 0.385, 95% CI 0.194 to 0.765), even in combination with heart failure (OR 0.220, 95% CI 0.077 to 0.632). CONCLUSIONS: Surgery during active LSIE seems to significantly reduce in-hospital mortality. The higher the risk, the higher the improvement in outcome.

Monitoring of motor and somatosensory systems in a 26-week pregnant woman.

INTRODUCTION: We report the case of a 34-year-old woman who was 26 weeks pregnant and needed a brain surgery. METHODS: We performed intraoperative neurophysiological monitoring (IONM) with motor-evoked potentials (MEP) elicited by transcranial electrical stimulation and somatosensory-evoked potentials (SSEP). Additionally, uterine myometric tone from the mother and fetal heart rate were also monitored. Forty-three MEP and 35 SSEP trains were applied (energy delivered, 2.35 and 0.45 J, respectively). FINDINGS: No changes related to electrical stimulation in either uterine muscle tone or fetal heart rate were observed. No motor or new somatosensory deficits appeared. CONCLUSION: Our findings suggest that IONM can be safely applied in pregnant women.

Language hemispheric dominance analyzed with magnetic resonance DTI: correlation with the Wada test.

OBJECTIVE: Language lateralization is a major concern in some patients with pharmacoresistant epilepsy who will face surgery; in these patients, hemispheric dominance testing is essential to avoid further complications. The Wada test is considered the gold standard examination for language localization, but is invasive and requires many human and material resources. Functional MRI and tractography with diffusion tensor imaging (DTI) have demonstrated that they could be useful for locating language in epilepsy surgery, but there is no evidence of the correlation between the Wada test and DTI MRI in language dominance. METHODS: The authors performed a retrospective review of patients who underwent a Wada test before epilepsy surgery at their institution from 2012 to 2017. The authors retrospectively analyzed fractional anisotropy (FA), number and length of fibers, and volume of the arcuate fasciculus and uncinate fasciculus, comparing dominant and nondominant hemispheres. RESULTS: Ten patients with temporal lobe epilepsy were reviewed. Statistical analysis showed that the mean FA of the arcuate fasciculus in the dominant hemisphere was higher than in the nondominant hemisphere (0.369 vs 0.329, p = 0.049). Also, the number of fibers in the arcuate fasciculus was greater in the dominant hemisphere (881.5 vs 305.4, p = 0.003). However, no differences were found in the FA of the uncinate fasciculus or number of fibers between hemispheres. The length of fibers of the uncinate fasciculus was longer in the dominant side (74.4 vs 50.1 mm, p = 0.05). Volume in both bundles was more prominent in the dominant hemisphere (12.12 vs 6.48 cm3, p = 0.004, in the arcuate fasciculus, and 8.41 vs 4.16 cm3, p = 0.018, in the uncinate fasciculus). Finally, these parameters were compared in patients in whom the seizure focus was situated in the dominant hemisphere: FA (0.37 vs 0.30, p = 0.05), number of fibers (114.4 vs 315.6, p = 0.014), and volume (12.58 vs 5.88 cm3, p = 0.035) in the arcuate fasciculus were found to be statistically significantly higher in the dominant hemispheres. Linear discriminant analysis of FA, number of fibers, and volume of the arcuate fasciculus showed a correct discrimination in 80% of patients (p = 0.024). CONCLUSIONS: The analysis of the arcuate fasciculus and other tract bundles by DTI could be a useful tool for language location testing in the preoperative study of patients with refractory epilepsy.

Prediction of Memory Impairment in Epilepsy Surgery by White Matter Diffusion.

OBJECTIVE: To analyze the relationship between cognitive performance and white matter integrity in patients with temporal lobe epilepsy (TLE) to establish radiologic criteria to help with patient selection for surgery. METHODS: The study included 19 adults with temporal lobe epilepsy. A tractography analysis of fractional anisotropy and mean diffusivity (MD) of the following fascicles was performed: arcuate fascicle, cingulum, fornix, inferior fronto-occipital fascicle, inferior longitudinal fascicle, parahippocampal fibers of the cingulum, and uncinate fascicle. The Wechsler Memory Scale-Third Edition neuropsychological test was performed to evaluate short- and long-term verbal (Logical Memory I and II subtests) and nonverbal (Visual Reproduction I and II subtests) memory. Relationships between memory scores and diffusion were calculated. RESULTS: Lower Logical Memory I subtest scores were correlated with lower MD of the right inferior fronto-occipital fascicle, while lower Logical Memory II subtest scores were related to higher values of fractional anisotropy in bilateral cingulum, right uncinate, and right parahippocampal fibers of the cingulum and lower MD in left cingulum fascicle. Finally, lower values in Visual Reproduction I subtest scores were associated with lower values in MD in right cingulum and inferior fronto-occipital fascicles. CONCLUSIONS: Structural changes of some white matter tracts were associated with deterioration of both short- and long-term memory. These alterations were more associated with verbal memory than with nonverbal memory. These changes mainly consist of an increase in fractional anisotropy and a decrease in MD, which could be interpreted as reorganization phenomena. Diffusion tensor imaging could be a useful tool for cognitive assessment in surgical candidates with temporal lobe epilepsy who are not suitable for neuropsychological testing or in whom their results do not lead to definitive conclusions.

Potential EEG biomarkers of sedation doses in intensive care patients unveiled by using a machine learning approach.

OBJECTIVE: Sedation of neurocritically ill patients is one of the most challenging situation in ICUs. Quantitative knowledge on the sedation effect on brain activity in that complex scenario could help to uncover new markers for sedation assessment. Hence, we aim to evaluate the existence of changes of diverse EEG-derived measures in deeply-sedated (RASS-Richmond agitation-sedation scale -4 and -5) neurocritically ill patients, and also whether sedation doses are related with those eventual changes. APPROACH: We performed an observational prospective cohort study in the intensive care unit of the Hospital de la Princesa. Twenty-six adult patients suffered from traumatic brain injury and subarachnoid hemorrhage were included in the present study. Long-term continuous electroencephalographic (EEG) recordings (2141 h) and hourly annotated information were used to determine the relationship between intravenous sedation infusion doses and network and spectral EEG measures. To do that, two different strategies were followed: assessment of the statistical dependence between both variables using the Spearman correlation rank and by performing an automatic classification method based on a machine learning algorithm. MAIN RESULTS: More than 60% of patients presented a correlation greater than 0.5 in at least one of the calculated EEG measures with the sedation dose. The automatic classification method presented an accuracy of 84.3% in discriminating between different sedation doses. In both cases the nodes' degree was the most relevant measurement. SIGNIFICANCE: The results presented here provide evidences of brain activity changes during deep sedation linked to sedation doses. Particularly, the capability of network EEG-derived measures in discriminating between different sedation doses could be the framework for the development of accurate methods for sedation levels assessment.

Morphometrical evaluation of decompression obtained through corpectomy. Heading towards to posterior approaches. / Evolución morfométrica de descompresión obtenida tras corpectomía. Dirigiéndonos hacia abordajes posteriores.

INTRODUCTION: We analysed the decompression obtained by dorsal or dorsolumbar corpectomy measured by Cobb angle and the spinal area prior to and after surgery and compared the evolution of the technique over the last five years of the study. MATERIAL AND METHOD: A retrospective review of patients operated between 2005 and 2015 through anterior or posterior approaches was performed. RESULTS: 24 patients were studied and a significant improvement was observed between the preoperative and postoperative morphometrical measurement (4.18° correction of the kyphosis and an increase of 130.8mm2 in the spinal canal, p<.001 in both cases) and in clinical parameters (45.8% of patients improved in ASIA, and Karnofsky showed 13 points of improvement, p<.001 in both cases). However, there was no correlation between clinical and morphological parameters. We also observed that in the last five years of the study posterior approaches were more frequently used with good results. CONCLUSIONS: Dorsal corpectomy allows significant spinal decompression, with neurological improvement but this does not correlate with the measurement of decompression. Thanks to technical improvements, less invasive techniques (posterior approaches and MISS) allow good clinical results, which are similar to those obtained by anterior techniques.

Identifying causal relationships between EEG activity and intracranial pressure changes in neurocritical care patients.

OBJECTIVE: To explore and assess the relationship between electroencephalography (EEG) activity and intracranial pressure (ICP) in patients suffering from traumatic brain injury (TBI) and subarachnoid hemorrhage (SAH) during their stay in an intensive care unit. APPROACH: We performed an observational prospective cohort study of adult patients suffering from TBI or SAH. Continuous EEG-ECG was performed during ICP monitoring. In every patient, variables derived from the EEG were calculated and the Granger causality (GC) methodology was employed to assess whether, and in which direction, there is any relationship between EEG and ICP. MAIN RESULTS: One-thousand fifty-five hours of continuous multimodal monitoring were analyzed in 21 patients using the GC test. During 37.88% of the analyzed time, significant GC statistic was found in the direction from the EEG activity to the ICP, with typical lags of 25-50 s between them. When recordings were adjusted by sedation-perfusion and/or bolus-and handling, these percentages hardly changed. SIGNIFICANCE: Long-lasting, continuous and simultaneous EEG and ICP recordings from TBI and SAH patients provide highly rich and useful information, which has allowed for uncovering a strong relationship between both signals. The use of this relationship could lead to developing a medical device to measure ICP in a non-invasive way.

Validation of Grading Scores and Outcome Prognostic Factors in Intracranial Meningiomas in Elderly Patients.

OBJECTIVE: Meningiomas are the most frequent benign intracranial tumors and they are becoming more frequent because of the aging population and advances in diagnostics and neurosurgical treatment. Therefore, there will be an increase of this disease in the coming years. METHODS: We performed a retrospective analysis of patients older than 70 years who underwent surgery for intracranial meningiomas, and we established risk factors related to outcome, morbidity, and mortality. We compared 3 previously described scores (Geriatric Scoring System [GSS], Clinico-Radiological Grading System [CRGS], and Sex, Karnofsky, ASA, Location and Edema [SKALE] score). RESULTS: We identified 110 patients older than 70 years. In the univariate analysis, postoperative Karnofsky Performance Status (KPS) was related to the presence of edema (P = 0.036), tumor size (P = 0.043), previous neurologic impairment (P = 0.012), and preoperative American Society of Anesthesiologists (ASA) physical status classification (P = 0.029). In the multivariable logistic regression model, ASA classification (odds ratio, 0.324; P = 0.04) and preoperative KPS (odds ratio, 1.042; P = 0.05) were also statistically significant. In all cases, better survival curves in the Kaplan-Meier survival test appear in patients with lower scores (CRGS, P = 0.015; GSS, P = 0.014; SKALE, P < 0.001). Also, morbidity measured as postoperative KPS correlated with these scores (CRGS, P < 0.001; SKALE, P < 0.001; GSS, P < 0.001). However, only SKALE correlated with perioperative morbidity, mortality, and 1-year mortality. CONCLUSIONS: Meningioma resection in patients older than 70 years is safe, with an acceptable rate of mortality and morbidity. Patients who should undergo surgery must be selected in relation to their comorbidities, such as ASA classification or preoperative KPS. However, SKALE could be a useful tool as an initial approach.