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Studies focused on the clinical profile of native valve endocarditis are scarce and outdated.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.

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 (S100β) 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.

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.

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 in left-sided infective endocarditis (LSIE) 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. Mean age was 64.9 years, 61% were male. Multivariate analysis of all patients was performed to determine if vegetation size is related to death in LSIE. Then, patients were divided in 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. Impact of surgery on mortality of 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=0.045). Group A had more valve rupture and valve regurgitation than group B, but heart failure (55% vs 53%, p=0.678), stroke (22% vs 17.0%, p=0.091), systemic embolism (39% vs 32%, p=0.074), perivalvular complication (28% vs 28%, p=0.865) or septic shock (15% vs 13%, p=0.288) 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, n=69 without surgery; mortality 18.6% vs 11.6% respectively, p=0.251).

CONCLUSIONS

large vegetations identify patients with poor outcome in 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.

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.

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.

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

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.

[Experience of implementing the ISO 9001:2015 standard for the accreditation of a paediatric hospital emergency department]

OBJECTIVE

The aim of this paper was to describe the process for accrediting a paediatric hospital emergency department to ISO 9001:2015 standards. The implementation process began in February 2015 and lasted 18months.

MATERIAL AND METHODS

The project started with the decision by the Head of Department to improve service quality. A Quality Committee was established with representation of the medical, nursing and administrative staff. Training sessions were held on quality management systems and ISO standards for employees. A meeting took place among members of the Emergency Department to define the main processes, and 14 were identified, documented and included in the processes map. Workgroups were then created to review and redesign the medical and nurse protocols.

RESULTS

Thirty-five medical and fifteen nursing protocols were incorporated into the management system, and quality indicators were established that allowed the whole process to be monitored. A risk register was created to record identified risks, their severity, likelihood of occurrence, and actions taken to prevent or reduce those risks. The Emergency Department underwent an external audit during June 2016, and was certified to the requirements demanded by the international ISO 9001:2015 standard.

CONCLUSIONS

The conclusion is that implementation of a quality management system on ISO and its certification is completely achievable, and has contributed to better patient management.

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.

Usefulness of Reintervention in Recurrent Glioblastoma: An Indispensable Weapon for Increasing Survival

BACKGROUND

Glioblastoma is the most frequent primary brain tumor and despite of complete treatment survival is still poor. The aim of this study is to define the utility of reoperation for improving survival in patients with recurrent glioblastoma, and determine other prognostic factors associated with longer survival.

METHODS

We performed a retrospective analysis of those patients who underwent surgery and compared those who were operated two or more times and those who received surgery only once. We studied overall survival (OS), progression-free survival (PFS), and clinical variables that could be related with higher survival.

RESULTS

A total of 121 patients were eligible for the study, of whom 31 (25%) underwent reoperation. The reoperation group had a mean and median increase survival of 10.5 and 16.4 months in OS and 3.5 and 2.7 months for PFS compared with the non-reoperation group (P < 0.001 and 0.01, respectively). Although complications were higher in patients that underwent reintervention (19.3%) there was no statistical difference with complication rate in first surgery (12.4%, χ² = 1.86; P = 0.40). Cox multivariable analysis revealed that age (hazard ratio [HR] 1.03; 95% confidence interval [CI], 1.006-1.055; P = 0.013), reoperation (HR, 0.48; 95% CI, 0.285-0.810; P = 0.006), extent of resection >95% (HR, 0.547; 95% CI, 0.401-0.748; P < 0.001), and complete adjuvant therapy (HR, 0.389; 95% CI, 0.208-0.726; P = 0.003) were correlated with a higher OS.

CONCLUSIONS

Reoperation and the extent of resection (EOR) are the only surgical variables that neurosurgeons can modify to improve survival in our patients. Higher EOR and reoperation rates in patients who can be candidates for second surgery, will increase OS and PFS.

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.

[Posthemorrhagic hydrocephalus in the preterm infant: current evidence in diagnosis and treatment]

Intraventricular haemorrhage and posthemorrhagic hydrocephalus are the most important neurological complications in preterm infants during the neonatal period. The prevalence of germinal matrix intraventricular haemorrhage widely varies depending on the population of study, but it is in any case increasing due both to the higher incidence of multiple and preterm deliveries as well as the longer survival of preterm infants favoured by recent advances in perinatal care. It is therefore of the utmost convenience to be familiar with the most important clinical evidence regarding this entity. However, the available evidence is often incomplete and piecemeal. The objective of the present review is to summarise the main diagnostic and therapeutic points regarding preterm related posthemorrhagic hydrocephalus. The participants of the working-group in Pediatric Neurosurgery of the Spanish Society of Neurosurgery were asked to write these recommendations down. This hopefully represents the first step towards the definition of a clinical guide in the treatment of complications related to periventricular hemorrhage of the preterm infants.

Morbidity associated with the use of foramen ovale electrodes

PURPOSE

The identification of the epileptic zone in patients with mesial temporal lobe epilepsy sometimes requires intracranial recordings, for example, with foramen ovale electrodes (FOE). This paper reviews and analyzes the resulting complications in a series of patients studied with bilateral FOE for presurgical evaluation.

METHODS

The clinical records of 331 consecutive FOE implantations in 329 patients were reviewed. Complications related to FOE were divided into two groups: those that were non-life-threatening or not directly attributable to FOE, or life-threatening complications and those clearly related to FOE.

RESULTS

The mean length of hospital stay in the v-EEG unit with FOE was 5.8 +/- 0.2 days (range 1-19) following a bimodal distribution (peaks at 4 and 8 days). Complications were observed in 6.64% of patients, but in 4.83% of cases, complications were non-life-threatening (moderate disaesthesia, cheek bleeding, FOE expulsion). Complications were only severe in 1.81% of patients (clotting or intracranial hemorrhage). One patient died more than 20 days after FOE removal and after several episodes of status epilepticus. Patients suffering from life-threatening complications were more likely to be female (83.3%) than patients experiencing no complications or non-life-threatening complications. Patients with life-threatening complications had a more prolonged stay in the v-EEG unit during monitoring with FOE (8.2 +/- 0.7; n = 6) than the group without complications (5.7 +/- 0.2; n = 309; p < 0.01; Kruskal-Wallis test).

DISCUSSION

FOE is a reasonably safe intracranial technique for v-EEG monitoring with low rates of potentially severe complications, but its indication should be carefully evaluated, especially if monitoring for more than 8 days is expected.

Surgical treatment of symptomatic cavernous malformations of the brainstem

INTRODUCTION AND OBJECTIVES

Cavernous malformations (CM) at the level of the brainstem, continue to present a challenge in therapeutic terms and are an important source of controversy. Here we present our experience and the results obtained by adopting surgical treatment.

MATERIALS AND METHODS

The results of a consecutive series of 17 patients were studied. The surgical intervention was designed after: 1. A neurological examination. 2. MRI and cerebral angiography. 3. Correlation with anatomical brainstem maps. The surgical intervention was approached from the most damaged zone or through a zone which was functionally least important.

RESULTS

Complete extirpation was achieved in 15 patients without mortality. In a few patients the surgical intervention temporarily aggravated the prior lesion of the cranial nerves (2/17) or damage new sensory tracts (2/17). The functional post-operative recovery was good, in terms of consciousness (4/5), cranial nerves (11/17), the pyramidal tract (3/5) and the cerebellum (2/4). Of the patients that were operated, 14 of 17 returned to their professional activities.

CONCLUSIONS

The results of surgery can surpass the morbidity-mortality of the natural history or treatment with radiosurgery. There is a clear consensus in recommending surgical intervention for CMs that are superficially located, in young patients and in those with a risk of further bleeding. It is probably best that the surgery is performed during the subacute period, when the MRI offers a clear image confirming the presence of the CM.

[Epidural fat in various diseases: contribution of magnetic resonance imaging and potential implications for neuro axial anesthesia]

Epidural fat is a reservoir of lipophilic substances that cushions the pulsatile movements of the dural sac, protects nerve structures, and facilitates the movement of the dural sac over the periosteum of the spinal canal during flexion and extension. Excessive epidural fat can compress the underlying structures, however, and affect the placement of catheters and the distribution of injected solutions. This review discusses changes in epidural fat related to various diseases and events: lipomatosis, epidural lymphoma, arachnoid cysts, epidural hematoma, meningiomas, angiolipomas, spondylolysis, scoliosis, spinal stenosis, and liposarcoma. Also discussed are the sequencing and protocols for magnetic resonance imaging that enable epidural fat to be observed and distinguished from neighboring structures. The relevance of epidural fat in spinal surgery is considered. Finally, we discuss the possible anesthetic implications of the abnormal deposition of epidural fat, to explain the unexpected complications that can arise during performance of epidural anesthesia.

[Characteristics and distribution of normal human epidural fat]

Epidural fat provides sufficient cushion for the pulsatile movements of the dural sac, protects nerve structures, facilitates the movement of the dural sac over the periosteum of the spinal column during flexion and extension, and forms a pharmacologic reservoir of lipophilic substances. We review epidural fat and related structures, including their development during the fetal period when the epidural space is filled by undifferentiated loose, areolar mesenchymal tissue that surrounds the dural sac. In the adult, epidural fat has a continuous distribution and follows a certain metameric pattern. It is located mainly on the dorsal side of the epidural space, where it is organized in triangular capsules joined to the midline of the ligamentum flavum by a vascular pedicle. We consider the distribution of epidural fat in the axial and sagittal planes; its presence in the anterior, lateral and posterior epidural space; its presence in the cervical, thoracic and lumbar portions of the spinal column; and its characteristics and variations according to differing body habits and sex. Finally, we speculate on the possible anesthetic implications of epidural fat in terms of the pharmacokinetics of drugs injected into the epidural space and the tasks of locating the epidural space and inserting an epidural catheter during anesthetic procedures.

Mobile phone text messaging in the management of diabetes

We conducted a trial of mobile phone text messaging (short message service; SMS) for diabetes management. In an eight-month period, 23 diabetic patients used the service. Patients used SMS to transmit data such as blood glucose levels and body weight to a server. The server automatically answered with an SMS acknowledgement message. A monthly calculated glycosylated haemoglobin result was also automatically sent to the patient by SMS. During the trial the patients sent an average of 33 messages per month. Although users showed good acceptance of the SMS diabetes system, they expressed various concerns, such as the inability to enter data from previous days. Nonetheless, the trial results suggest that SMS may provide a simple, fast and efficient adjunct to the management of diabetes. It was particularly useful for elderly persons and teenagers, age groups that are known to have difficulty in controlling their diabetes.

Web-based diabetes control

We developed a diabetes management system with a Web interface that allowed patients to transmit their physiological data using either a PC Web browser or a mobile phone capable of working with the WAP protocol. The system could generate automatic responses to input values in accordance with a set of ranges previously defined for each user. User analysis was carried out with personal and online questionnaires. During a nine-month study period on the island of Tenerife, 12 patients were recruited. On average, they used the system every 2.0 days (SD 2.1) and the doctors reviewed their patient data every 4.0 days (SD 3.9). The average number of visits to the Website was 477 per month. Users were satisfied with the continuity and self-efficacy of care, but lack of time was a drawback for 38% of them and 75% expressed a preference for sending their data via the mobile phone short message service (SMS).

[Intracranial and spinal subdural hematoma: a rare complication of epidural and subarachnoid anesthesia]

Subdural and epidural hematomas complicating central blocks are rare but serious complications that can lead to permanent neurological deficits. This review discusses cranial and spinal subdural hematomas, including the history of this complication in the literature. Theories to explain the mechanisms by which hematomas are formed are presented and risk factors are analyzed. The associations between such hematomas and the design of the various needles used for lumbar puncture are evaluated and the most common cranial and spinal locations are discussed. The anatomy of tissues that envelop and contain chronic subdural hematomas are described and the various neurological alterations that can develop are mentioned. Finally, diagnostic imaging options and corrective surgical techniques are reviewed.

In vivo changes after mechanical injury

Chondrocytes undergo apoptosis in response to mechanical injury in vitro. The current clinical study correlates arthroscopic and magnetic resonance imaging results with biopsy specimens of cartilage from patients with knee injury. Twenty patients were evaluated at a mean 2.7 months after acute knee injury. The mean age of the patients was 32 years and the mean weight was 83 kg. Cartilage lesions were graded separately on magnetic resonance images and arthroscopy in a blinded manner. During arthroscopy, a 1.8 mm diameter biopsy specimen was obtained from the edge of cartilage lesion. The biopsy specimen underwent histologic examination by safranin O staining and detection of chondrocyte apoptosis by the presence of deoxyribonucleic acid fragmentation. There was a positive correlation in 50% (10 of 20) when the presence or absence of cartilage lesions by magnetic resonance imaging was correlated with arthroscopy. All cases of partial thickness or full-thickness cartilage loss that were seen by arthroscopy also were detected by magnetic resonance images. Apoptotic cells were significantly more numerous in biopsy specimens from lesions compared with control biopsy specimens. The findings of reduced cell viability attributable to apoptosis may have profound implications for cartilage repair. This opens potential therapeutic avenues for the treatment of posttraumatic cartilage lesions through apoptosis prevention.

[A study of the motor and sensory cortex using functional magnetic resonance: tasks of active and passive movement]

INTRODUCTION AND OBJECTIVE

The objective of this study was to locate the rolandic area (pre- and post-central) by means of functional magnetic resonance imaging (FMRI) and define its correspondence on a Talairach map, whilst active and passive movements of the dominant hand were performed.

MATERIAL AND METHODS

Ten healthy volunteers were found, 6 men and 4 women, of an average age of 26 years (range 22-33). Two appropriate tasks were designed: one involving active and one passive movement. The examination was carried out using a 1.5 Tesla (General Electric) MRI apparatus. An echo-sequence of planar echo-gradient (BOLD technique) was used, making sagittal and axial planes, parallel to the AC-PC line (anterior commissure-posterior commissure). Subsequently an anatomofunctional Talairach map was drawn for each subject, to include the information obtained on FMRI.

RESULTS

In all subjects central activity was detected in the rolandic area during the tasks involving selected active and passive movements. Overlap was seen between the pre- and post-rolandic areas with both types of tasks.

CONCLUSION

There is good correlation between the image obtained of motor-sensory activity in the rolandic zone and the Talairach anatomofunctional map.

[Memory disorders in epileptic patients. A study of pre-postsurgical follow-up]

In general terms, epileptic patients with temporal lobe epilepsy (TLE) show mnesic deficits. In the case of medically intractable epilepsy (around 20%) the neurosurgery intervention is a widely accepted treatment. The cognitive effects of surgery have been reported in last years; they emphasize the mnesic positive changes of contralateral area. In the same sense they have reported a negative change on mnesic modality in ipsilateral area. This paper present a study in which the mnesic deficits of twenty eight pharmaco resistant epileptic patients have been evaluated and followed up. These patients have been submittes to a surgical treatment at the Epilepsy Surgical Unit of the Hospital de La Princesa (Madrid). The assessment pre and postoperative tested six months apart. The most common cognitive deficit affect bimodally to mnesic functions: so in the verbal as in the visospatial modality. This deficit correlated with the years epilepsy. Meanwhile, the following up study indicates that a relevant numbers of these patients show an improvement in the function of the contralateral hemisphere with respect to the area surgically treated. This finding probably is the consequence of seizure free.

Inhibitory neurons in the human epileptogenic temporal neocortex. An immunocytochemical study

Immunocytochemical methods were used to study alterations in inhibitory neuronal circuits in human neocortex resected during surgical treatment of intractable temporal epilepsy associated or not with brain tumours. The epileptogenic cortex was characterized and divided into spiking or non-spiking zones by intraoperative electrocorticography (ECOG). The resected cortex was cut into blocks, sectioned and stained immunocytochemically for visualization of glutamic acid decarboxylase (GAD), the calcium-binding protein, parvalbumin (PV) and glial fibrillary acidic protein (GFAP). A variety of alterations in cortical neuronal circuits as revealed by immunocytochemical and histological methods were found. Similar alterations in inhibitory neuronal circuits appear to occur independently of the primary epileptogenic site and pathology associated with epilepsy, which suggests that there is possibly a common basic underlying mechanism that leads to seizure activity. These changes were apparently unrelated to ECOG findings at surgery, which bring into question the value of the use of interictal epileptic discharges recorded by ECOG to guide cortical resections. The most conspicuous and common change was the loss of chandelier cells. The finding that these cells are among the most vulnerable types of GABAergic interneurons in the epileptogenic temporal cortex indicates that they might be of great functional importance, since the axon terminals of chandelier cells are likely to exert powerful regulation of impulse generation in cortical pyramidal cells. Therefore, these cells might represent a key component in the aetiology of human epilepsy.

Selective changes in the microorganization of the human epileptogenic neocortex revealed by parvalbumin immunoreactivity

The microanatomy of the human lateral temporal cortex removed from patients with intractable temporal lobe epilepsy was studied using correlative light and electron microscopic immunocytochemical methods for the localization of the calcium-binding protein parvalbumin (PV). PV immunostaining was mainly used to label a subpopulation of powerful cortical inhibitory interneurons that have been shown to be lost at epileptic foci in certain animal models of epilepsy. In the human neocortex with normal appearance, we identified the same local neuronal circuitry as in the normal monkey cortex, but in some regions of the same cortex, a fine disorganization of neuronal circuits (loss of inhibitory neurons and presumptive thalamocortical terminals) was found. This abnormal circuitry may interfere with normal cerebral activity in epileptic patients. These results also indicate that PV immunoreactivity can be a useful tool to study normal and abnormal synaptic circuits in the human cerebral cortex.

The immediate and long-term effects of mannitol and glycerol. A comparative experimental study

A prolonged experimental situation of focal vasogenic oedema, producing mild intracranial hypertension, was developed. The aim was to study the immediate and long-term effects of repeated infusions of mannitol and glycerol on intracranial pressure (ICP) and cerebral blood flow (CBF). Eighteen goats were operated on twice to implant: an epidural latex balloon in each cerebral hemisphere to measure ICP; an electromagnetic flowmeter around both internal maxillary arteries (the only cerebral blood input), after tying the extracranial branches, to measure the CBF; and two femoral catheters to measure blood pressure (BP) and for intravenous infusion (IV). Three groups of 6 goats each were formed: A) control; the BP and bilateral ICPs and CBFs were recorded under basal conditions and every 4 hours for 3 days after a cold injury (CI) was provoked; B) 20% mannitol solution 1 g/kg body weight injected every 12 hr starting at 24 hr post-CI; and C) 10.1% glycerol solution 0.5 g/kg body weight, administered as mannitol. Glycerol, as compared to mannitol, presents the following major differences among its immediate post infusion effects: a lesser decrease in ICP, but no rebound phenomenon; lesser elevation of BP; CBF increases more gradually and constantly. Long-term effects with mannitol consisted of a rebound phenomenon observed in ICP during the last 12 hr. In all 3 groups, it was observed that CBF increases in relation to the ICP level.

Trans-fissural or trans-sulcal approach versus combined stereotactic-microsurgical approach

The combined stereotactic-microsurgical approach has been used mainly to allow the removal of small subcortical lesions, determining their location and the route to be followed. In our experience, this approach has been most useful in 5 cases of small paraventricular AVMs and another 6 small deep-seated tumoural lesions. Since the availability of MRI, we have systematically applied Yasargil's proposal to perform dissection of the cisterns or sulci to reach a lesion with minimal or no injury to normal neuroanatomy. Assisted by Computer Aided Design software, we can superimpose the MR images with those provided by conventional or digital angiography (mainly the venous phase). MRI allows us to select a route or pathway through a sulcus, and angiography helps us in locating it on the brain surface. We have applied this technique systematically during the past year, and can report 20 cases (1 AVM, 12 tumoural lesions, 1 abscess and 6 haematomas). This trans-fissural or trans-sulcal approach has allowed us resection with minimal surgical damage, after a prompt and precise location. We think that both methods are not mutually exclusive, although the trans-sulcal approach is more adequate because of less discomfort for the patient, the smaller cerebral parenchyma injury and greater anatomofunctional information for the surgeon.

[A comparative study of myelography and CAT in patients with lumbo-sciatica]

One hundred patients with acute lumbo sciatica symptoms probably due to disc hernia, have been studied. A CT scan and a myelography was performed in all patients. The clinical and radiologic (myelography and CT scan) findings have been evaluated in three categories based on their intensity and a correlation between these three parameters has been performed. Our results show a positivity of 94% in the clinical signs, 87% in the myelography findings and 88% in CT scan findings. The correlation results show that in very severe lumbo sciatica syndromes there is a greater positivity in the myelography than in CT scan findings and that there could be big radiologic changes without a clear clinical repercussion.