The ERK phosphorylation levels in the amygdala predict anxiety symptoms in humans and MEK/ERK inhibition dissociates innate and learned defensive behaviors in rats.

We demonstrate that the rate of extracellular signal-related kinase phosphorylation (P-ERK1,2/Total-ERK1,2) in the amygdala is negatively and independently associated with anxiety symptoms in 23 consecutive patients with drug-resistant mesial temporal lobe epilepsy that was surgically treated. In naive Wistar rats, the P-ERK1,2/Total-ERK1,2 ratio in the amygdala correlates negatively with innate anxiety-related behavior on the elevated plus maze (n = 20) but positively with expression of defensive-learned behavior (i.e., freezing) on Pavlovian aversive (fear) conditioning (n = 29). The microinfusion of ERK1/2 inhibitor (FR180204, n = 8-13/group) or MEK inhibitor (U0126, n = 8-9/group) into the basolateral amygdala did not affect anxiety-related behavior but impaired the evocation (anticipation) of conditioned-defensive behavior (n = 9-11/group). In conclusion, the P-ERK1,2/Total-ERK1,2 ratio in the amygdala predicts anxiety in humans and the innate anxiety- and conditioned freezing behaviors in rats. However, the ERK1/2 in the basolateral AMY is only required for the expression of defensive-learned behavior. These results support a dissociate ERK-dependent mechanism in the amygdala between innate anxiety-like responses and the anticipation of learned-defensive behavior. These findings have implications for understanding highly prevalent psychiatric disorders related to the defensive circuit manifested by anxiety and fear. HIGHLIGHTS: The P-ERK1,2/Total-ERK1,2 ratio in the amygdala (AMY) correlates negatively with anxiety symptoms in patients with mesial temporal lobe epilepsy. The P-ERK1,2/Total-ERK1,2 in the amygdala correlates negatively with the anxiety-like behavior and positively with freezing-learned behavior in naive rats. ERK1,2 in the basolateral amygdala is required for learned-defensive but not for the anxiety-like behavior expression in rats.

Amygdala levels of the GluA1 subunit of glutamate receptors and its phosphorylation state at serine 845 in the anterior hippocampus are biomarkers of ictal fear but not anxiety.

Fear is a conscious state caused by exposure to real or imagined threats that trigger stress responses that affect the body and brain, particularly limbic structures. A sub-group of patients with mesial temporal lobe epilepsy related to hippocampus sclerosis (MTLE-HS) have seizures with fear, which is called ictal fear (IF), due to epileptic activity within the brain defensive survival circuit structures. Synaptic transmission efficacy can be bi-directionally modified through potentiation (long-term potentiation (LTP)) or depression (long-term depression (LTD)) as well as the phosphorylation state of Ser831 and Ser845 sites at the GluA1 subunit of the glutamate AMPA receptors, which has been characterized as a critical event for this synaptic plasticity. In this study, GluA1 levels and the phosphorylation at Ser845 and Ser831 in the amygdala (AMY), anterior hippocampus (aHIP) and middle gyrus of temporal neocortex (CX) were determined with western blots and compared between MTLE-HS patients who were showing (n = 06) or not showing (n = 25) IF. Patients with IF had an 11% decrease of AMY levels of the GluA1 subunit (p = 0.05) and a 21.5% decrease of aHIP levels of P-GluA1-Ser845 (p = 0.009) compared to patients not showing IF. The observed associations were not related to imbalances in the distribution of other concomitant types of aura, demographic, clinical or neurosurgical variables. The lower levels of P-GluA1-Ser845 in the aHIP of patients with IF were not related to changes in the levels of the serine/threonine-protein phosphatase PP1-alpha catalytic subunit or protein kinase A activation. Taken together, the GluA1 subunit levels in AMY and P-GluA1-Ser845 levels in the aHIP show an overall accuracy of 89.3% (specificity 95.5% and sensitivity 66.7%) to predict the presence of IF. AMY levels of the GluA1 subunit and aHIP levels of P-GluA1-Ser845 were not associated with the psychiatric diagnosis and symptoms of patients. Taken together with previous findings in MTLE-HS patients with IF who were evaluated by stereotactic implanted depth electrodes, we speculate our findings are consistent with the hypothesis that AMY is not a centre of fear but together with other sub-cortical and cortical structures integrates the defensive circuit that detect and respond to threats. This is the first report to address neuroplasticity features in human limbic structures connected to the defensive survival circuits, which has implications for the comprehension of highly prevalent psychiatric disorders and symptoms.

Determinants for Meaningful Clinical Improvement of Pain and Health-Related Quality of Life After Spinal Cord Stimulation for Chronic Intractable Pain.

OBJECTIVES: Previous studies demonstrated significant improvement in mean pain scores and quality of life (QOL) scales in patients with chronic pain who underwent spinal cord stimulation (SCS). However, the number of individuals who experience relevant improvements in QOL, termed the meaningful clinical improvement (MCI), is not known. The present study investigated changes in pain measurements based on MCI after SCS. MATERIALS AND METHODS: Thirty-four patients with chronic intractable pain completed scales of pain (visual analogue scale [VAS]), QOL (SF-36), and psychological dimensions during a 22-month follow-up period (mean). Patient-centered MCI of the VAS and SF-36 domain scores were determined based on the MacNab criteria of surgical global effectiveness. Independent presurgical predictors for MCI in the VAS and SF-36 domains were analyzed using multiple binary logistic regression. RESULTS: There was significant improvement of pain and QOL after the SCS (p < 0.00001). Twenty-three patients (67.6%) reached an MCI of pain, and 16 (47.7%)-23 (67.7%) reported an MCI of QOL. Predictors of MCI included ≥80% paresthesia coverage of the painful area, lower levels of anxiety and catastrophizing symptoms, shorter pain duration, female gender and no use of opioids before surgery. MCI of pain and QOL was observed in 50%-70% of patients with chronic pain after SCS. CONCLUSIONS: The identification of determinants for MCI is a challenge to improve the accuracy of prognostic models in SCS for patients with chronic pain. Our results, if confirmed in other populations with a larger sample size, have implications for patients with chronic pain who are candidates for SCS treatment.

Evaluation of high-grade astrocytoma recurrence patterns after radiotherapy in the era of temozolomide: A single institution experience.

AIM: Evaluating the recurrence patterns of high-grade astrocytomas in patients who were treated with radiotherapy (RT) plus temozolomide (TMZ). BACKGROUND: The current literature suggests that reducing the margins added to the CTV does not significantly change the risk of recurrence and overall survival; thus, we decided to analyze our data and to examine the possibility of changing the adopted margins. MATERIALS AND METHODS: From February 2008 till September 2013, 55 patients were treated for high-grade astrocytomas, 20 patients who had been confirmed to have recurrence were selected for the present study. Post-operative MRI was superimposed on the planning CT images in order to correlate the anatomical structures with the treatment targets. Recurrences were defined according to the Response Assessment Criteria for Glioblastoma. The mean margins of the PTVinitial and PTVboost were 1.2 cm and 1.4 cm, respectively. The analysis of the percentage of the recurrence volume (Volrec) within the 100% isodose surface was based on the following criteria: (I) Central: >95% of the Volrec; (II) In-field: 81-95% of the Volrec; (III) Marginal: 20-80% of the Volrec; and (IV) Outside: <20% of the Volrec. RESULTS: Of the 20 patients, 13 presented with central recurrences, 3 with in-field recurrences, 2 with marginal recurrences and 2 with outside recurrences. Therefore, the lower Volrec within 100% of the prescribed dose was considered in the classification. CONCLUSIONS: Of the selected patients, 80% had ≥81-95% of the Volrec within 100% of the prescribed dose and predominantly had central or in-field recurrences. These results are comparable with those from the literature.

Predictors of meaningful improvement in quality of life after temporal lobe epilepsy surgery: A prospective study.

OBJECTIVES: To investigate prospectively the independent predictors of a minimum clinically important change (MCIC) in quality of life (QOL) after anterior temporal lobectomy (ATL) for drug-resistant mesial temporal lobe epilepsy related to hippocampal sclerosis (MTLE-HS) in Brazilian patients. METHODS: Multiple binary logistic regression analysis was performed to identify the clinical, demographic, radiologic, and electrophysiologic variables independently associated with MCIC in the Quality of Life in Epilepsy-31 Inventory (QOLIE-31) overall score 1 year after ATL in 77 consecutive patients with unilateral MTLE-HS. RESULTS: The overall QOLIE-31 score and all its subscale scores increased significantly (p < 0.0001) 1 year after ATL. In the final logistic regression model, absence of presurgical diagnosis of depression (adjusted odds ratio [OR] 4.4, 95% confidence interval [CI] 1.1-16.1, p = 0.02) and a complete postoperative seizure control (adjusted OR 4.1, 95% CI 1.2-14.5, p = 0.03) were independently associated with improvement equal to or greater than the MCIC in QOL after ATL. The overall model accuracy for MCIC improvement in the QOL was 85.6%, with a 95.2% of sensitivity and 46.7% of specificity. SIGNIFICANCE: These results in Brazilian patients reinforce the external validation of previous findings in Canadian patients showing that presurgical depression and complete seizure control after surgery are independent predictors for meaningful improvement in QOL after ATL, and have implications for the surgical management of MTLE patients.

Decline in word-finding: The objective cognitive finding most relevant to patients after mesial temporal lobe epilepsy surgery.

PURPOSE: The purpose of this study was to investigate the following: i) the objective impairment in neuropsychological tests that were associated with the subjective perception of cognitive function decline in Brazilian patients who underwent mesial temporal lobe epilepsy (MTLE) surgery and ii) the predictive variables for those impaired objective neuropsychological tests. METHODS: Forty-eight adults with MTLE (27 right HS and 23 male) were divided according to their perception of changes (Decline or No-decline) of cognitive function domain of the QOLIE-31 questionnaire applied before and 1year after the ATL. The mean (SD) of changes in the raw score difference of the neuropsychological tests before and after the ATL was compared between Decline and No-decline groups. Receiver Operating Characteristic curves, sensitivity, specificity, and predictive values were used to assess the optimum cutoff points of neuropsychological test score changes to predict patient-reported subjective cognitive decline. KEY FINDINGS: Six (12.5%) patients reported a perception of cognitive function decline after ATL. Among the 25 cognitive tests analyzed, only changes in the Boston Naming Test (BNT) were associated with subjective cognitive decline reported by patients. A reduction of ≥8 points in the raw score of BNT after surgery had 91% of sensitivity and 45% specificity for predicting subjective perception of cognitive function decline by the patient. Left side surgery and age older than 40years were more associated with an important BNT reduction with overall accuracy of 91.7%, 95% predictive ability for no impairment, and 75% for impairment of cognitive function. SIGNIFICANCE: Impairment in word-finding seems to be the objective cognitive finding most relevant to Brazilian patients after mesial temporal lobe epilepsy surgery. Similar to American patients, the side of surgery and age are good predictors for no decline in the BNT, but shows a lower accuracy to predict its decline. If replicated in other populations, the results may have wider implications for the surgical management of patients with drug-resistant MTLE.

Mitochondrial Respiration Chain Enzymatic Activities in the Human Brain: Methodological Implications for Tissue Sampling and Storage.

Mitochondrial respiratory chain complexes enzymatic (MRCCE) activities were successfully evaluated in frozen brain samples. Epilepsy surgery offers an ethical opportunity to study human brain tissue surgically removed to treat drug resistant epilepsies. Epilepsy surgeries are done with hemodynamic and laboratory parameters to maintain physiology, but there are no studies analyzing the association among these parameters and MRCCE activities in the human brain tissue. We determined the intra-operative parameters independently associated with MRCCE activities in middle temporal neocortex (Cx), amygdala (AMY) and head of hippocampus (HIP) samples of patients (n = 23) who underwent temporal lobectomy using multiple linear regressions. MRCCE activities in Cx, AMY and HIP are differentially associated to trans-operative mean arterial blood pressure, O2 saturation, hemoglobin, and anesthesia duration to time of tissue sampling. The time-course between the last seizure occurrence and tissue sampling as well as the sample storage to biochemical assessments were also associated with enzyme activities. Linear regression models including these variables explain 13-17 % of MRCCE activities and show a moderate to strong effect (r = 0.37-0.82). Intraoperative hemodynamic and laboratory parameters as well as the time from last seizure to tissue sampling and storage time are associated with MRCCE activities in human samples from the Cx, AMYG and HIP. Careful control of these parameters is required to minimize confounding biases in studies using human brain samples collected from elective neurosurgery.

Variables associated with physical health-related quality of life in Parkinson's disease patients presenting for deep brain stimulation.

Deep brain stimulation (DBS) benefits Parkinson's disease (PD) patient's quality of life specially in domains as mobility, activities of daily living (ADL) and bodily discomfort (BD), but little is known about the variables associated with these HRQOL domains in patients presenting for DBS. The objective is to evaluate variables associated with of HRQOL in a Brazilian sample of PD patients presenting for DBS treatment, specifically in the domains related with motor symptoms. In a cross-sectional study of 59 PD patients evaluated at outpatient Unit for Movement Disorders, multiple linear regression analysis was performed to identify independent variables associated with mobility, ADL and BD domains of the 39-item Parkinson's disease questionnaire (PDQ-39). UPDRS III "on" scores, duration of the disease, age, presence of comorbidities and anxiety and depressive symptoms quantified by hospital anxiety and depression scale (HADS), were the independent variables. In our results, HADS scores were independently associated to mobility domain: ß coefficient 1.36 (95 % CI 0.55-2.15) and BD domain: ß coefficient 1.57 (95 % CI 0.67-2.48). UPDRS III "on" scores were independently associated to mobility domain: 0.42 (95 % CI 0.03-0.81). The model of each multiple linear regression analysis explains 25 % of the mobility domain variability (p < 0.01) and 24 % of the BD domain variability (p < 0.01). Psychiatric symptoms were at least as relevant to quality of life as motor symptoms in PD patients presenting for DBS treatment. The effect of treating these psychiatric symptoms on patients' HRQOL deserves further investigation.

Role of hormonal levels on hospital mortality for male patients with severe traumatic brain injury.

INTRODUCTION: Changes in hormone blood levels during the acute phase of traumatic brain injury (TBI) have been described in the literature. The objective was to investigate the association among several hormones plasma levels in the acute phase of severe TBI and the hospital mortality rate of male patients. METHODS: The independent association among plasma levels of TSH, LH, FSH, GH, free T4, cortisol, IGF-1 and total testosterone was measured 10 hours and 30 hours after severe TBI and the hospital mortality of 60 consecutive male patients was evaluated. RESULTS: At least one hormonal level abnormality was demonstrated in 3.6-73.1% of patients. The multiple logistic regressions showed a trend for an independent association among hospital mortality and normal or elevated LH levels measured at 10 hours (OR = 3.7, 95% CI = 0.8-16.3, p = 0.08) and 30 hours (OR = 3.9, 95% CI = 0.9-16.7, p = 0.06). Admission with abnormal pupils and a lower Glasgow Coma Score also were independently associated with hospital mortality. CONCLUSION: The hormonal changes are frequent in the acute phase of severe TBI. The hormones plasma levels, excepting the LH, are not highly consistent with the hospital mortality of male patients.

Predictors of quality of life in patients with refractory mesial temporal lobe epilepsy.

PURPOSE: The identification of variables associated with health-related quality of life (HRQoL) in patients with mesial temporal lobe epilepsy related to hippocampal sclerosis (MTLE-HS) would improve surgical decision-making and post-operatory follow-up in this group of patients. METHODS: We analyzed the independent association between the Quality of Life in Epilepsy Inventory-31 (QOLIE-31) of 81 consecutive patients with refractory MTLE-HS. The clinical, demographic, radiological and electrophysiological variables were analyzed by multiple linear regression analysis. KEY FINDINGS: Approximately 36% (adjusted R(2)=0.36; R coefficient=0.66) of the QOLIE-31 overall score variance was explained by the history of initial precipitant injury, family history of epilepsy, disease duration, age of epilepsy onset, seizure frequency and presence of psychiatric axis-II diagnosis. The variance of QOLIE-31 sub-scales was: seizure worry=7%; overall QOL=11%; emotional well-being=32%; energy/fatigue=38%; cognitive function=13%; medication effects=7%; social function=13% (R coefficient between 0.30 and 0.65). SIGNIFICANCE: The pre-surgical variables studied had relatively low prediction capacity for the overall QOLIE-31 score and its sub-scales in this set of Brazilian patients with refractory MTLE-HS.

Hospital mortality of patients with severe traumatic brain injury is associated with serum PTX3 levels.

BACKGROUND: Traumatic brain injury (TBI) is a worldwide cause of morbidity and mortality. Pentraxin 3 (PTX3) is a humoral component of the innate immune system which has been studied as a marker of inflammatory, infections or cardiovascular pathologies. To investigate the association between serum levels of PTX3 and the hospital mortality of patients with severe TBI. METHODS: The independent association between serum PTX3 levels after severe TBI (Glasgow Coma Scale, GCS ≤ 8) and hospital mortality was analyzed in a prospective study of 83 consecutive patients by a multiple logistic regression analysis. The leukocyte count in the same sample was analyzed as another marker of inflammatory response. RESULTS: The mean age of patients was 35 years and 85% were male. Serum PTX3 levels were determined 18.0 (SD ± 17.0) h after TBI. Patients who died showed a mean serum PTX3 level of 9.95 µg/ml (SD ± 6.42) in comparison to 5.46 µg/ml (SD ± 4.87) of the survivor group (P = 0.007). Elevated serum PTX3 levels remain significantly associated with mortality (P = 0.04) in the subset of patients with isolated TBI (n = 34). There were no differences in the leukocytes count measured in the same blood sample used for PTX3 determination in survivors and non-survivors (P = 0.56). The final multiple logistic regression model including age, pupillary examination, GCS, associated trauma, and PTX3 levels shows that serum levels of PTX3 which were higher than 10 µg/ml were independently associated with the patients mortality (adjusted OR 3.06, CI 95% 1.03-9.15, P = 0.04). CONCLUSIONS: Serum PTX3 levels after severe TBI are independently associated with higher hospital mortality and may be a useful marker of TBI and its prognosis.

AMPAr GluA1 Phosphorylation at Serine 845 in Limbic System Is Associated with Cardiac Autonomic Tone.

The central autonomic network, which is connected to the limbic system structures including the amygdala (AMY) and anterior hippocampus (aHIP), regulates the sympathetic and parasympathetic modulation of visceromotor, neuroendocrine, pain, and behavior manifestations during stress responses. Heart rate variability (HRV) is useful to estimate the cardiac autonomic tone. The levels of phosphorylation on the Ser831 and Ser845 sites of the GluA1 subunit of the AMPAr (P-GluA1-Ser845 and P-GluA1-Ser831) are useful markers of synaptic plasticity. The relation between synaptic plasticity in the human limbic system structures and autonomic regulation in humans is unknown. This study investigated the association between HRV and neurochemistry biomarkers of synaptic plasticity in AMY and aHIP. HRV indices were obtained from the resting state electrocardiogram of patients with drug-resistant mesial temporal lobe epilepsy (MTLE, n = 18) and the levels of P-GluA1-Ser845 and P-GluA1-Ser831 in the AMY and aHIP resected during the epilepsy surgery. A backward stepwise multiple linear regression models were used to analyze the association between HRV and synaptic plasticity biomarkers controlling for imbalances in the distribution of sociodemographic, clinical, neuroimaging, and neurosurgical variables. P-GluA1-Ser845 levels in AMY show a negative association (p < 0.05) with the 3 investigated parasympathetic autonomic HRV indices (SDNN, rMSSD, and HF) predicting 24 to 40% of their variation. The final multiple linear regression models include disease duration and levels of P-GluA1-Ser845 and predict 24 to 56% of cardiac autonomic tone variation (p < 0.01). P-GluA1-Ser845 levels in AMY and aHIP are negatively associated with the resting HRV in MTLE-HS indicating that increased synaptic efficiency in amygdala is associated with a parasympathetic cardiac autonomic tone impairment. The results suggest that specific changes in synaptic plasticity may be involved in the brain-heart axis regulation by the limbic system.

Sporadic intramedullary spinal cord hemangioblastoma in a newborn.

BACKGROUND: Hemangioblastomas (HB) are rare lesions accounting for 2% of all spinal cord tumors. They are highly vascular, benign tumors that occur either sporadically or in the presence of von Hippel-Lindau disease. Spinal cord HB are usually diagnosed in adult patients and their incidence in early infancy is an extreme rarity. METHODS: We present a case of a 1-month-old male with a back deformity and left leg hypomotility. MRI of the spine revealed an intramedullary tumor extending from level T6 to T12. RESULTS: The tumor was excised completely, using standard microsurgical techniques via a posterior approach. The histological diagnosis was spinal cord HB. CONCLUSION: A review of the literature revealed that this neoplasm is composed of 3 major cell types: endothelial cells, pericytes and stromal cells. Complete microsurgical removal is the treatment of choice for spinal cord HB because the tumor is benign. To the best of our knowledge, sporadic spinal cord HB at this age has not been reported so far.

Mortality in severe traumatic brain injury: a multivariated analysis of 748 Brazilian patients from Florianópolis City.

BACKGROUND: Traumatic brain injury (TBI) is a major cause of incapacity and mortality worldwide, with most of the burden occurring in low-income and middle-income countries. A number of clinical, demographic, and neurosurgical variables of patients with TBI were associated with their outcome. METHODS: We investigated the mortality of Brazilian patients with severe TBI at the time of discharge, using a multiple logistic regression analysis. Clinical, demographic, radiologic, and neurosurgical variables, and mortality at time of discharge of all consecutive patients (n = 748) with severe TBI (admission Glasgow scale < or = 8) treated in our intensive care unit were analyzed. The variables were collected in a prospective manner between January 1994 and December 2003. RESULTS: Eighty-four percent (n = 631) of the patients were men. The mean age was 34.8 (+/-16.3) years and the mortality was 33.3%. After the multiple logistic regression, the adjusted odds ratio (OR) for death was higher in older (> 60 years) than younger (up to 30 years) patients (OR = 2.51, 95% confidence interval [CI] 1.31-4.79, p = 0.006). The mortality was also associated with sub-arachnoid hemorrhage (OR = 1.86, 95% CI = 1.23-2.81, p = 0.003) on computed tomography (CT) scan; admission Glasgow Scale of 3 or 4 in comparison to 7 or 8 (OR = 3.97, 95% CI = 2.49- 6.31, p < 0.001); bilateral midryasis (OR = 11.52, 95% CI = 5.56-23.87, p < 0.0001), or anisocoria (OR = 2.65, 95% CI = 1.69-4.17, p < 0.0001) in comparison to isocoric pupils. There was a trend for higher mortality in patients with type III injury on the Marshall classification of CT (OR = 3.63, 95% CI = 0.84-15.76, p = 0.08) than in patients with normal CT. Patients without thoracic trauma disclose higher mortality than patients with associated thoracic trauma do (OR = 2.02, 95% CI = 1.19-3.41, p = 0.009). The final model presented disclosed 76.9% of overall correct prediction with the survival and death predicted at 87.6% and 55.6%, respectively. CONCLUSION: Age, CT findings, Glasgow coma scale, pupil examination, and the presence of thoracic trauma at admission were independently associated with mortality at the time of discharge in Brazilian patients with severe TBI.

Predictors of Pain Recurrence After Lumbar Facet Joint Injections.

INTRODUCTION: Facet joint injections (FJIs) of anesthetic and corticosteroids are useful for the diagnosis and treatment of low back pain (LBP). In the current study, we evaluated the efficacy of FJI on LBP treatment and the predictive variables of pain recurrence after FJI. METHODS: We included and followed prospectively forty-three consecutive patients with chronic LBP treated with FJI. Clinical assessments were carried out at a baseline 1 week before FJIs and after a 6-month follow-up visit using the visual analog scale (VAS) for pain, Oswestry Disability Index (ODI) for disability-specific measure and MacNab criteria for global effectiveness, and compared through analysis using paired-samples "t" tests. Multiple cox-regression analysis was used to identify the presurgical variables independently associated with pain recurrence anytime during the follow-up. In addition to the demographic, clinical, and surgical data, we also analyzed psychometric scales: Pain Catastrophizing Scale (PCS), Beck Anxiety Inventory (BAI), and Beck Depression Inventory (BDI). RESULTS: After a 6-month follow-up, thirty-two patients (74.4%) showed a clinically significant reduction of pain and twenty-seven (62.8%) reported a clinically significant improvement of disability. Presurgical catastrophizing (PCS score ≥ 5, adjusted HR 4.4, CI 95% 1.7-11.3, p = 0.002) and smoking (Adjusted HR 12.5, CI 95% 1.1-138.9, p = 0.04) remains associated with pain recurrence. CONCLUSION: FJI reduces LBP and disability of patients with unresponsive LBP. Pain-related cognitive and behavioral factors determined by pain catastrophizing and smoking were independently associated with pain recurrence after lumbar FJI. The results support the need of a multidisciplinary approach for presurgical evaluation of patients with chronic pain.

Neuropsychological functioning and brain energetics of drug resistant mesial temporal lobe epilepsy patients.

Interictal hypometabolism is commonly measured by 18-fluoro-deoxyglucose Positron Emission Tomography (FDG-PET) in the temporal lobe of patients with mesial temporal lobe epilepsy (MTLE-HS). Left temporal lobe interictal FDG-PET hypometabolism has been associated with verbal memory impairment, while right temporal lobe FDG-PET hypometabolism is associated with nonverbal memory impairment. The biochemical mechanisms involved in these findings remain unknown. In comparison to healthy controls (n=21), surgically treated patients with MTLE-HS (n=32, left side=17) had significant lower scores in the Rey Auditory Verbal Learning Test (RAVLT retention and delayed), Logical Memory II (LMII), Boston Naming test (BNT), Letter Fluency and Category Fluency. We investigated whether enzymatic activities of the mitochondrial enzymes Complex I (C I), Complex II (C II), Complex IV (C IV) and Succinate Dehydrogenase (SDH) from the resected samples of the middle temporal neocortex (mTCx), amygdala (AMY) and hippocampus (HIP) were associated with performance in the RAVLT, LMII, BNT and fluency tests of our patients. After controlling for the side of hippocampus sclerosis, years of education, disease duration, antiepileptic treatment and seizure outcome after surgery, no independent associations were observed between the cognitive test scores and the analyzed mitochondrial enzymatic activities (p>0.37). Results indicate that memory and language impairment observed in MTLE-HS patients are not strongly associated with the levels of mitochondrial CI, CII, SDH and C IV enzymatic activities in the temporal lobe structures ipsilateral to the HS lesion.

Prevalence of trigeminal neuralgia: A systematic review.

BACKGROUND: The aim of this systematic review was to answer the focused question, "What are the prevalence and the epidemiological characteristics of trigeminal neuralgia in the general population?" TYPES OF STUDIES REVIEWED: This systematic review included observational population-based studies reporting the prevalence of trigeminal neuralgia (TN). The authors developed specific search strategies for LILACS, PubMed, ScienceDirect, Scopus, Web of Science, and Google Scholar. The authors evaluated the methodological quality of the included studies using criteria from the Agency for Healthcare Research and Quality. RESULTS: Among 728 studies, the authors selected only 3 for inclusion. Two studies were classified as having low risk of bias and 1 as having moderate risk. The sample size ranged from 1,838 to 13,541 adults. This review identified a higher prevalence of TN in women, ranging from 0.03% (95% confidence interval [CI], 0.01-0.08) to 0.3% (95% CI, 0.16-0.55). The maxillary and mandibular branches of the trigeminal nerve were the most affected. The proportion between women and men who had TN was 3 to 1, and those in the age bracket between 37 and 67 years were the most affected. CONCLUSIONS AND PRACTICAL IMPLICATIONS: The authors of this review identified a higher prevalence of TN in women older than 40 years that usually affected the maxillary and mandibular branches. Further research is required to validate the prevalence of TN in a well-structured, population-based study without a convenience sample.

Normal brain mitochondrial respiration in adult mice lacking cellular prion protein.

Cellular prion protein (PrP(c)) gene (Prnp) null mice (Prnp0/0) show higher sensitivity to seizures, enhanced brain oxidative stress, and their neurons exhibit higher excitability "in vitro". Mitochondrial respiration is a useful parameter for the determination of cellular metabolic rate and it is a major source of reactive oxygen species (ROS). In the present study, we investigated the mitochondrial function of different brain areas of Prnp0/0 adult mice and then compared this to normal control animals. Baseline mitochondrial respiration (stages 3 and 4), respiratory control ratio (RCR) and membrane potential were evaluated in the neocortex, entorhinal cortex, hippocampus, and cerebellum. No differences in these parameters were detected between Prnp0/0 and wild-type mice. Thus, we concluded that baseline mitochondrial respiration might not be directly related with the higher oxidative stress previously observed in brains from Prnp0/0 mice.

Limited predictive power of hospitalization variables for long-term cognitive prognosis in adult patients with severe traumatic brain injury.

OBJECTIVES: Traumatic brain injury (TBI) is a main cause of mortality and morbidity. Association studies between hospitalization variables and cognitive impairment after TBI are frequently retrospective, including non-consecutive patients showing variable degrees of TBI severity, and poor management of missing (drop out) cases. METHODS: We assessed prospectively the demographic and hospitalization variables of 234 consecutive patients with severe TBI (admission Glasgow Coma Scale [GCS] ≤8) and determined their independent association with cognitive performance in a representative sample (n = 46) of surviving patients (n = 172) evaluated 3 (±1.8) years after hospitalization. RESULTS: In all, 85% of patients were male and the mean age was 34 (SD ±13) years. The education level was 9 (±4.7) years. As expected, education and age showed a moderately to strong linear relationship with the cognitive performance in 14 of 15 neuropsychological tests (R coefficient = 0.6-0.8). The cognitive test scores were not independently associated with gender, admission GCS, associated trauma, and Marshal CT classification. Admission-elevated blood glucose levels and the presence of sub-arachnoid haemorrhage were independently associated with lower scores on Rey Auditory Verbal Learning retention and Logical Memory-I tests, respectively. CONCLUSIONS: After correction for education and age distribution, the variables that are commonly associated with mortality or Glasgow Outcome Scale including admission pupils' examination, Marshal CT Classification, GCS, and serum glucose showed a limited predictive power for long-term cognitive prognosis. Identification of clinical, radiological, and laboratory variables as well as new biomarkers independently associated with cognitive outcome remains an important challenge for further work involving severe TBI patients.