Resting-State EEG Signature of Early Consciousness Recovery in Comatose Traumatic Brain Injury Patients

Background Resting-state electroencephalogram (rsEEG) is usually obtained to assess seizures in comatose patients with traumatic brain injury (TBI) patients. We aim to investigate rsEEG measures and their prediction of early recovery of consciousness in comatose TBI patients. Methods This is a retrospective study of comatose TBI patients who were admitted to a level-1 trauma center (10/2013-1/2022). Demographics, basic clinical data, imaging characteristics, and EEG data were collected. We calculated using 10-minute rsEEGs: power spectral density (PSD), permutation entropy (PE - complexity measure), weighted symbolic-mutual-information (wSMI - global information sharing measure), Kolmogorov complexity (Kolcom - complexity measure), and heart-evoked potentials (HEP - the averaged EEG signal relative to the corresponding QRS complex on electrocardiogram). We evaluated the prediction of consciousness recovery before hospital discharge using clinical, imaging, rsEEG data via Support Vector Machine with a linear kernel (SVM). Results We studied 113 (out of 134, 84%) patients with rsEEGs. A total of 73 (65%) patients recovered consciousness before discharge. Patients who recovered consciousness were younger (40 vs. 50, p .01). Patients who recovered consciousness had higher Kolcom (U = 1688, p = 0.01,), increased beta power (U = 1652 p = 0.003), with higher variability across channels ( U = 1534, p = 0.034), and epochs (U = 1711, p = 0.004), lower delta power (U = 981, p = 0.04) and showed higher connectivity across time and channels as measured by wSMI in the theta band (U = 1636, p = .026, U = 1639, p = 0.024) than those who didn't recover. The ROC-AUC improved from 0.66 (using age, motor response, pupils' reactivity, and CT Marshall classification) to 0.69 (p < 0.001) when adding rsEEG measures. Conclusion We describe the rsEEG EEG signature in recovery of consciousness prior to discharge in comatose TBI patients. Resting-state EEG measures improved prediction beyond the clinical and imaging data.

Deep Brain Stimulation for an Unusual Presentation of Myoclonus Dystonia Associated with Russell-Silver Syndrome

Background

Myoclonus dystonia syndrome typically results from autosomal dominant mutations in the epsilon-sarcoglycan gene (SGCE) via the paternally expressed allele on chromosome 7q21. There is evidence that deep brain stimulation (DBS) is beneficial for this genotype, however, there are few prior case reports on DBS for myoclonus dystonia syndrome secondary to other confirmed genetic etiologies.

Case Report

A 20-year-old female with concomitant Russell-Silver syndrome and myoclonus dystonia syndrome secondary to maternal uniparental disomy of chromosome 7 (mUPD7) presented for medically refractory symptoms. She underwent DBS surgery targeting the bilateral globus pallidus interna with positive effects that persisted 16 months post-procedure.

Discussion

We present a patient with the mUPD7 genotype for myoclonus dystonia syndrome who exhibited a similar, if not superior, response to DBS when compared to patients with other genotypes.

Highlights

This report outlines the first described case of successful deep brain stimulation treatment for a rare genetic variant of myoclonus dystonia syndrome caused by uniparental disomy at chromosome 7. These findings may expand treatment options for patients with similar conditions.

Robotic-Assisted Stereoelectroencephalography: A Systematic Review and Meta-Analysis of Safety, Outcomes, and Precision in Refractory Epilepsy Patients

Robotic assistance in stereoelectroencephalography (SEEG) holds promising potential for enhancing accuracy, efficiency, and safety during electrode placement and surgical procedures. This systematic review and meta-analysis, following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and International Prospective Register of Systematic Reviews (PROSPERO) registration, delves into the latest advancements and implications of robotic systems in SEEG, while meticulously evaluating outcomes and safety measures. Among 855 patients suffering from medication-refractory epilepsy who underwent SEEG in 29 studies, averaging 24.6 years in age, the most prevalent robots employed were robotic surgical assistant (ROSA) (450 patients), Neuromate (207), Sinovation (140), and ISys1 (58). A total of 8,184 electrodes were successfully implanted, with an average operative time of 157.2 minutes per procedure and 15.1 minutes per electrode, resulting in an overall mean operative time of 157.7 minutes across all studies. Notably, the mean target point error (TPE) stood at 2.13 mm, the mean entry point error (EPE) at 1.48 mm, and postoperative complications occurred in 7.69% of robotically assisted (RA) SEEG cases (60), with 85% of these complications being asymptomatic. This comprehensive analysis underscores the safety and efficacy of RA-SEEG in patients with medication-refractory epilepsy, characterized by low complication rates, reduced operative time, and precise electrode placement, supporting its widespread adoption in clinical practice, with no discernible differences noted among the various robotic systems.

Navigated Dorsal Root Ganglion Stimulation (DRGS) for the Treatment of Chronic Refractory Coccygodynia: A Case Report

Sacral stimulation is a well-established therapy for urologic neuromodulation. After the advent of dorsal root ganglion (DRG) stimulation, pain surgeons have started to reach this target mostly for pelvic and sacral pain. For those without good surgical experience, sacral foramen puncture, especially S3 and S4, can be a challenge, due to its entry angle and limited C-arm image resolution. In this report, we describe a new technique to utilize sacral navigation using the O-arm approach to guide DRG stimulation implants. We discuss a case of a 53-year-old male patient with refractory coccygodynia, who underwent sacral DRG implantation using neuronavigation. Punctures could be done without the need for multiple attempts to reach the foramen in this patient.

Middle Meningeal Artery Embolization for Chronic Subdural Hematoma Related to Autosomal Dominant Polycystic Kidney Disease

Autosomal dominant polycystic kidney disease (ADPKD) is a connective tissue disease with vascular abnormalities involving multiple organs. The prevalence of ADPKD associated with a spontaneous subdural hematoma (SDH) is very low, with less than 10 cases reported in the literature to date. Symptomatic chronic SDH is classically treated with a twist drill, burr holes, or craniotomy. Recently, middle meningeal artery (MMA) embolization has emerged as an ancillary modality. We present the first case in the literature of a bilateral SDH in a young ADPKD patient successfully managed with MMA embolization. Moreover, we discuss the role of different treatment modalities on this subset of patients.

The Cost of Gunshot Wounds to the Head: An Unevenly Distributed Burden

BACKGROUND

Despite the significant clinical consequences and socioeconomic costs of gunshot wounds to the head (GSWH), studies examining prehospital risk factors, geospatial patterns, and economic cost are lacking.

METHODS

A retrospective analysis was performed for patients with GSWH (single or multiple injuries) presenting to the level one Ryder Trauma Center (hospital patients) as well as the Miami-Dade County Medical Examiner (ME) Department, from October 2013 to October 2015. In addition, ME data were queried from the previous decade (2008-2017) to analyze longitudinal trends.

RESULTS

A total of 402 consecutive patients met the inclusion criteria: 297 (74%) presented to the ME and 105 (26%) presented to the hospital. GSWH in our cohort had a case fatality rate of 89%, predominantly affecting males, whites, and individuals who committed suicide, with a mean age of 41.9 ± 20.6 years. Hospital patients were more likely to be black males from low socioeconomic status (SES) regions involved in assault. Older white males were overrepresented in patients attempting and completing suicide and thus comprised a higher percentage of ME cases. Geospatial analysis of hospital patient injury zip codes shows that GSWH are significantly clustered in low-income urban centers with greater poverty rates. In Miami-Dade County, the economic burden of GSWH, as measured by total health care costs and lifetime productivity losses, was estimated to be $11,867,415 and $246,179,498, respectively.

CONCLUSIONS

In the first analysis of GSWH with the inclusion of both hospital and ME data in a representative urban setting, our findings show prehospital risk factors and the unequal distribution of the significant economic costs of GSWH.

Source-sink connectivity: a novel interictal EEG marker for seizure localization

Over 15 million epilepsy patients worldwide have drug-resistant epilepsy. Successful surgery is a standard of care treatment but can only be achieved through complete resection or disconnection of the epileptogenic zone, the brain region(s) where seizures originate. Surgical success rates vary between 20% and 80%, because no clinically validated biological markers of the epileptogenic zone exist. Localizing the epileptogenic zone is a costly and time-consuming process, which often requires days to weeks of intracranial EEG (iEEG) monitoring. Clinicians visually inspect iEEG data to identify abnormal activity on individual channels occurring immediately before seizures or spikes that occur interictally (i.e. between seizures). In the end, the clinical standard mainly relies on a small proportion of the iEEG data captured to assist in epileptogenic zone localization (minutes of seizure data versus days of recordings), missing opportunities to leverage these largely ignored interictal data to better diagnose and treat patients. IEEG offers a unique opportunity to observe epileptic cortical network dynamics but waiting for seizures increases patient risks associated with invasive monitoring. In this study, we aimed to leverage interictal iEEG data by developing a new network-based interictal iEEG marker of the epileptogenic zone. We hypothesized that when a patient is not clinically seizing, it is because the epileptogenic zone is inhibited by other regions. We developed an algorithm that identifies two groups of nodes from the interictal iEEG network: those that are continuously inhibiting a set of neighbouring nodes ('sources') and the inhibited nodes themselves ('sinks'). Specifically, patient-specific dynamical network models were estimated from minutes of iEEG and their connectivity properties revealed top sources and sinks in the network, with each node being quantified by source-sink metrics. We validated the algorithm in a retrospective analysis of 65 patients. The source-sink metrics identified epileptogenic regions with 73% accuracy and clinicians agreed with the algorithm in 93% of seizure-free patients. The algorithm was further validated by using the metrics of the annotated epileptogenic zone to predict surgical outcomes. The source-sink metrics predicted outcomes with an accuracy of 79% compared to an accuracy of 43% for clinicians' predictions (surgical success rate of this dataset). In failed outcomes, we identified brain regions with high metrics that were untreated. When compared with high frequency oscillations, the most commonly proposed interictal iEEG feature for epileptogenic zone localization, source-sink metrics outperformed in predictive power (by a factor of 1.2), suggesting they may be an interictal iEEG fingerprint of the epileptogenic zone.

EPID-23. TRAUMATIC BRAIN INJURY AND SUBSEQUENT BRAIN TUMOR DEVELOPMENT: A SYSTEMATIC REVIEW OF THE LITERATURE

Background The role of prior head trauma in stimulating brain tumor development has been previously described in the literature but continues to be debated. The goal of this study was to conduct a systematic review interrogating the contemporary literature to delineate any possible relationship between traumatic brain injury and brain tumor development. Methods A systematic review exploring development of post-TBI brain tumor was conducted by searching electronic databases. Abstracts from articles were read and selected for full-text review according to criteria previously established in the scientific literature. Relevant full-text articles were divided into case reports and single-arm studies and epidemiological studies. Results Of 1070 resultant articles, 18 case reports and single-arm studies (level of evidence of IV and V) with 45 patients were included. The most common cause of TBI was traffic accidents. The average period between TBI and subsequent tumor diagnosis was 12.8 years. Meningiomas represented the largest share of tumors, followed by gliomas. Most post-TBI brain tumors developed in the frontal and temporal lobes. Fifteen epidemiological studies were also interrogated from a variety of countries (level of evidence of III). Case–control studies were more common than cohort studies. There were 9 of 15 studies proposed a possible relationship between history of head trauma and development of brain tumor. Conclusion The relationship between head trauma and neoplastic growth continues to be heavily debated. There are certainly case reports and epidemiological studies in the literature that suggest a correlational relationship between the two. However, there is no concrete evidence of a causal relationship between TBI and brain tumors. More research is needed to definitively delineate the extent of any such relationship.

Simple Wound Closure for Civilian Cranial Gunshot Wounds: A Systematic Literature Review

Civilian cranial gunshot wounds are common injuries associated with significant morbidity and mortality. Simple wound closure has been previously proposed as an alternative treatment option for a small subset of patients, but the exact outcomes of this strategy are not well-defined. The objective of this paper was to describe the scientific literature reporting simple wound closure of civilian cranial gunshot wounds, its effect on short-term and long-term neurologic outcomes, and rates of seizures and infections. A systematic literature review was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. The strength of evidence was assessed using the Grading of Recommendation, Assessment, Development, and Evaluation (GRADE) criteria. Seventeen studies were found that met inclusion criteria. There was very low strength of evidence that patients treated with simple wound closure can achieve good short and long-term neurologic outcomes. There was very low strength of evidence that simple wound closure has a higher incidence of mortality compared to operative intervention, especially in patients with initial low Glasgow Coma Scale (GCS) scores. There was very low strength of evidence that patients treated with simple wound closure have a small risk of subsequently developing infections or seizures. In conclusion, under most circumstances, neurosurgical operative intervention should be viewed as the optimal treatment for salvageable civilian cranial gunshot wound patients. However, our literature review showed that simple wound closure is safe and viable. More data are needed to determine the appropriate clinical scenario for using this alternative option.

Current Trends in Mild Traumatic Brain Injury

In this review, we provide an overview of the current research and treatment of all types of traumatic brain injury (TBI) before illustrating the need for improved care specific to mild TBI patients. Contemporary issues pertaining to acute care of mild TBI including prognostication, neurosurgical intervention, repeat radiographic imaging, reversal of antiplatelet and anticoagulation medications, and cost savings initiatives are reviewed. Lastly, the effect of COVID-19 on TBI is addressed.

Implantable brain-computer interface for neuroprosthetic-enabled volitional hand grasp restoration in spinal cord injury

Loss of hand function after cervical spinal cord injury severely impairs functional independence. We describe a method for restoring volitional control of hand grasp in one 21-year-old male subject with complete cervical quadriplegia (C5 American Spinal Injury Association Impairment Scale A) using a portable fully implanted brain-computer interface within the home environment. The brain-computer interface consists of subdural surface electrodes placed over the dominant-hand motor cortex and connects to a transmitter implanted subcutaneously below the clavicle, which allows continuous reading of the electrocorticographic activity. Movement-intent was used to trigger functional electrical stimulation of the dominant hand during an initial 29-weeks laboratory study and subsequently via a mechanical hand orthosis during in-home use. Movement-intent information could be decoded consistently throughout the 29-weeks in-laboratory study with a mean accuracy of 89.0% (range 78-93.3%). Improvements were observed in both the speed and accuracy of various upper extremity tasks, including lifting small objects and transferring objects to specific targets. At-home decoding accuracy during open-loop trials reached an accuracy of 91.3% (range 80-98.95%) and an accuracy of 88.3% (range 77.6-95.5%) during closed-loop trials. Importantly, the temporal stability of both the functional outcomes and decoder metrics were not explored in this study. A fully implanted brain-computer interface can be safely used to reliably decode movement-intent from motor cortex, allowing for accurate volitional control of hand grasp.

Intracranial Hypertension After Primary Decompressive Craniectomy for Head Trauma

BACKGROUND

Primary decompressive craniectomy (DC) is commonly performed for patients with traumatic brain injury (TBI). Some, but not all patients, will benefit from invasive monitoring of intracranial pressure (ICP) after surgery. We intended to identify risk factors for elevated ICP after primary DC to treat TBI.

METHODS

A retrospective chart review study identified all patients at our institution who underwent primary DC for TBI during the study period and who had ICP monitors placed at the time of surgery. Various preoperative and intraoperative variables were assessed for correlation with the presence of postoperative elevated ICP.

RESULTS

Postoperative elevated ICP occurred in 36% of patients after DC. In univariate analysis, Glasgow Coma Scale <8, abnormal pupillary examination, and intraoperative brain swelling were all associated with elevated postoperative ICP. However, in multivariate analysis only intraoperative brain swelling was associated with elevated postoperative ICP (incidence 56% vs. 5%, P = 0.0043).

CONCLUSIONS

Placement of an ICP monitor at the time of primary DC for patients with TBI should be considered if there is intraoperative brain swelling.

Neural fragility as an EEG marker of the seizure onset zone

Over 15 million patients with epilepsy worldwide do not respond to drugs. Successful surgical treatment requires complete removal or disconnection of the seizure onset zone (SOZ), brain region(s) where seizures originate. Unfortunately, surgical success rates vary between 30 and 70% because no clinically validated biological marker of the SOZ exists. We develop and retrospectively validate a new electroencephalogram (EEG) marker-neural fragility-in a retrospective analysis of 91 patients by using neural fragility of the annotated SOZ as a metric to predict surgical outcomes. Fragility predicts 43 out of 47 surgical failures, with an overall prediction accuracy of 76% compared with the accuracy of clinicians at 48% (successful outcomes). In failed outcomes, we identify fragile regions that were untreated. When compared to 20 EEG features proposed as SOZ markers, fragility outperformed in predictive power and interpretability, which suggests neural fragility as an EEG biomarker of the SOZ.

Hypothermia for Patients Requiring Evacuation of Subdural Hematoma: A Multicenter Randomized Clinical Trial

Background

Hypothermia is neuroprotective in some ischemia–reperfusion injuries. Ischemia–reperfusion injury may occur with traumatic subdural hematoma (SDH). This study aimed to determine whether early induction and maintenance of hypothermia in patients with acute SDH would lead to decreased ischemia–reperfusion injury and improve global neurologic outcome.

Methods

This international, multicenter randomized controlled trial enrolled adult patients with SDH requiring evacuation of hematoma within 6 h of injury. The intervention was controlled temperature management of hypothermia to 35 °C prior to dura opening followed by 33 °C for 48 h compared with normothermia (37 °C). Investigators randomly assigned patients at a 1:1 ratio between hypothermia and normothermia. Blinded evaluators assessed outcome using a 6-month Glasgow Outcome Scale Extended score. Investigators measured circulating glial fibrillary acidic protein and ubiquitin C-terminal hydrolase L1 levels.

Results

Independent statisticians performed an interim analysis of 31 patients to assess the predictive probability of success and the Data and Safety Monitoring Board recommended the early termination of the study because of futility. Thirty-two patients, 16 per arm, were analyzed. Favorable 6-month Glasgow Outcome Scale Extended outcomes were not statistically significantly different between hypothermia vs. normothermia groups (6 of 16, 38% vs. 4 of 16, 25%; odds ratio 1.8 [95% confidence interval 0.39 to ∞], p = .35). Plasma levels of glial fibrillary acidic protein (p = .036), but not ubiquitin C-terminal hydrolase L1 (p = .26), were lower in the patients with favorable outcome compared with those with unfavorable outcome, but differences were not identified by temperature group. Adverse events were similar between groups.

Conclusions

This trial of hypothermia after acute SDH evacuation was terminated because of a low predictive probability of meeting the study objectives. There was no statistically significant difference in functional outcome identified between temperature groups.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12028-021-01334-w.

Treatment strategies for patients with concurrent blunt cerebrovascular and traumatic brain injury

Patients who present with traumatic brain injury (TBI) combined with blunt cerebrovascular injuries (BCVI) are difficult to manage, in part because treatment for each entity may exacerbate the other. It is necessary to develop a treatment paradigm that ensures maximum benefit while mitigating the opposing risks. A cohort of 150 patients from 2015 to present, with either internal carotid artery (ICA) and/or vertebral artery (VA) dissections or pseudoaneurysms, was cross-referenced with those who had sustained TBI. Of the 38 patients identified with both TBI and BCVI, 25 suffered ICA injuries, 10 had VA injuries and 3 had combined ICA/VA injuries. Unilateral BCVI occurred in 30 patients, while 8 had bilateral BCVI. Two patients required surgical intervention for TBI, and 5 patients required endovascular intervention for BCVI. Positive emboli detection studies (EDS) on transcranial dopplers (TCD) were demonstrated in 19 patients, with 9 patients having radiographic evidence of stroke. Anti-platelet therapy was initiated in 32 patients, and anti-coagulation in 10 patients, without new or worsening intracranial hemorrhages (ICH). Overall, 76% of patients were able to be discharged home or to rehabilitation, with good recovery demonstrated in 73% of the patients who had appropriate follow-up. In the setting of concurrent TBI and BCVI, use of anti-platelet/coagulation to prevent stroke can be safe if monitored closely. Here we describe a treatment paradigm which weighs the risk and benefits of therapies based on severity of ICH and stroke prevention, which tended to result in good disposition and recovery.

Deep learning for robust detection of interictal epileptiform discharges

OBJECTIVE

Automatic detection of interictal epileptiform discharges (IEDs, short as ``spikes'') from an epileptic brain can help predict seizure recurrence and support the diagnosis of epilepsy. Developing fast, reliable and robust detection methods for IEDs based on scalp or intracortical EEG may facilitate online seizure monitoring and closed-loop neurostimulation.

APPROACH

We developed a new deep learning approach, which employs a long short-term memory (LSTM) network architecture (``IEDnet'') and an auxiliary classifier generative adversarial network (AC-GAN), to train on both expert-annotated and augmented spike events from intracranial electroencephalography (iEEG) recordings of epilepsy patients. We validated our IEDnet with two real-world iEEG datasets, and compared IEDnet with the support vector machine (SVM) and random forest (RF) classifiers on their detection performances.

MAIN RESULTS

IEDnet achieved excellent cross-validated detection performances in terms of both sensitivity and specificity, and outperformed SVM and RF. Synthetic spike samples augmented by AC-GAN further improved the detection performance. In addition, the performance of IEDnet was robust with respect to the sampling frequency and noise. Furthermore, we also demonstrated the cross-institutional generalization ability of IEDnet while testing between two datasets.

SIGNIFICANCE

IEDnet achieves excellent detection performances in identifying interictal spikes. AC-GAN can produce augmented iEEG samples to improve supervised deep learning.

Do Benzodiazepines Impair Motor and Nonmotor Symptoms in a Sample of Parkinson's Disease Patients?

Background Anxiety and sleep disturbances are prevalent in Parkinson's disease (PD). Benzodiazepines (BZDs) are commonly used to treat these symptoms; however, they are associated with unfavorable side effects such as falls and cognitive slowing in the general non-PD population. Examining the effects of BZDs in PD is imperative as these medications could pose an increased risk to PD patients who are already vulnerable to falls and cognitive deficits. Methods Eighty-four patients diagnosed with idiopathic PD, of which 60% were Hispanic, underwent clinical evaluations including the Unified Parkinson's Disease Rating Scale (UPDRS) and comprehensive neuropsychological testing examining global cognition, language, visuospatial skills, memory, executive function, mood, and sleep quality. Thirty-six patients taking BZDs (BZD+) were compared to forty-eight patients not using any BZDs (BZD-) employing appropriate statistical tests depending on the measures' characteristics. Results BZD+ PD patients performed below the BZD- group on short-term memory but not on delayed recall, and performed better on a measure of visuospatial judgment. The BZD+ group endorsed more symptoms of anxiety and depression as well as poorer sleep quality. No significant differences were noted on other measures of cognition or motor function. Conclusion PD patients taking BZDs may experience select changes in cognition and mood. These changes are isolated and mild, and suggest that for some patients, BZDs may be a viable pharmacologic intervention that does not alter cognitive and motor function compared to those not taking these medications.

The Effects of Lockdown During the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Pandemic on Neurotrauma-Related Hospital Admissions

Background

The response to the global severe acute respiratory syndrome coronavirus 2 pandemic culminated in mandatory isolation throughout the world, with nationwide confinement orders issued to decrease viral spread. These drastic measures were successful in “flattening the curve” and maintaining the previous rate of coronavirus disease 2019 infections and deaths. To date, the effects of the coronavirus disease 2019 pandemic on neurotrauma has not been reported.

Methods

We retrospectively analyzed hospital admissions from Ryder Trauma Center at Jackson Memorial Hospital, during the months of March and April from 2016 to 2020. Specifically, we identified all patients who had cranial neurotrauma consisting of traumatic brain injury and/or skull fractures, as well as spinal neurotrauma consisting of vertebral fractures and/or spinal cord injury. We then performed chart review to determine mechanism of injury and if emergent surgical intervention was required.

Results

Compared with previous years, we saw a significant decline in the number of neurotraumas during the pandemic, with a 62% decline after the lockdown began. The number of emergent neurotrauma surgical cases also significantly decreased by 84% in the month of April. Interestingly, although the number of vehicular traumas decreased by 77%, there was a significant 100% increase in the number of gunshot wounds.

Conclusions

Population seclusion had a direct effect on the frequency of neurotrauma, whereas the change in relative proportion of certain mechanisms may be associated with the psychosocial effects of social distancing and quarantine.

Revisiting eligibility for deep brain stimulation: Do preoperative mood symptoms predict outcomes in Parkinson's disease patients?

INTRODUCTION

Anxiety and depression are common in PD, occurring in an estimated 30%-40% of PD patients. However, the extent to which these emotional symptoms interfere with Deep Brain Stimulation (DBS) outcomes is not well established. This study examined the association between pre-operative emotional well-being and postsurgical cognitive, emotional, and motor performance in PD.

METHODS

Forty-nine PD patients underwent neurological, neuropsychological (global cognition, processing speed, language, visuospatial, memory), and emotional assessments pre- and post-DBS. Fifteen patients were administered the UPDRS. Patients were divided into Anxious (Anx; n = 21), Comorbid Anxious and Depressed (Anx + Dep; n = 15), and Emotionally Asymptomatic (EA; n = 13) based on BAI and BDI-II cutoffs, and compared on pre-post changes in neurocognitive, mood, and motor scores using analyses of covariance (ANCOVA), controlling for education, ethnicity, and disease duration.

RESULTS

Pre-DBS, there were no significant differences between the three groups on any neuropsychological measure. Overall change from pre-to post-DBS revealed declines on multiple cognitive measures and lower symptom endorsement on the BAI among all participants. No group differences were observed on neurocognitive measures, mood, or UPDRS.

CONCLUSIONS

PD patients with mild-moderate anxiety or comorbid anxiety/depression pre-DBS do not show greater cognitive, emotional, and motor changes post-DBS compared to emotionally asymptomatic patients. These data emphasize the importance of discussing potential DBS outcomes, while keeping in mind that psychiatric comorbidity should not necessarily exclude patients from DBS. The notion that premorbid mood symptoms could disqualify a candidate for surgery would be a disservice, as this group performs comparably to asymptomatic peers.

To Drain or Two Drains: Recurrences in Chronic Subdural Hematomas

BACKGROUND

Chronic subdural hematoma (cSDH) is a common neurosurgical condition, with an estimated incidence of 3-15.5 per 100,000 people, with significantly higher rates in the elderly population. Recurrence rates range from 2%-37% after surgical drainage. Studies have shown that leaving a drain postoperatively can reduce recurrence rates, but studies have not looked at whether there is a difference between leaving 1 or 2 drains.

METHODS

We analyzed 215 patients undergoing burr hole drainage for 261 cSDHs in terms of preoperative comorbidities and postoperative drain placement.

RESULTS

Recurrences requiring repeat evacuation occurred in 6.1% overall, in 6/110 patients (5.5%) with 1 burr hole, and in 11/151 patients (7.3%) who had 2 burr holes, which was not significantly different. Recurrences occurred in 1/15 patients (6.7%) with no drain, 13/210 patients (6.2%) with 1 drain, and in 2/36 patients (5.6%) with 2 drains, which was also not statistically significant. The only medical comorbidity associated with an increased risk of recurrence was liver disease (P = 0.014).

CONCLUSIONS

This study demonstrates that neither the number of burr holes nor the number of drains left after a burr hole drainage of cSDH appear to affect recurrence rates, whereas liver disease does make recurrence more likely.

Deep Brain Stimulation Utilizing Dexmedetomidine: A Clinical Report from the University of Miami Miller School of Medicine

Background: Deep brain stimulation (DBS) is an increasingly utilized technique to treat symptoms of neurological movement disorders, most commonly, Parkinson’s Disease. Patients and surgeons alike appreciate the minimally invasive nature of this procedure, as well as its reversibility. As these surgeries are being performed more often, it is becoming increasingly important to optimize our anesthetic management during these cases. Methods: We conducted a retrospective review of the DBS procedures that have been performed at our institution utilizing monitored anaesthesia care (MAC) via dexmedetomidine infusion to report on the frequency and type of perioperative complications as well as to assess the effectiveness of this technique. Results: A total of 150 patients and 174 lead placements were included in this study. Dexmedetomidine was the sole anaesthetic used in 85.6% of cases. The remaining cases used a combination of dexmedetomidine and adjuvant agents. A total of one perioperative complication was found in our series, resulting in a total complication rate percentage per patient of 0.6%.Conclusions: We found very few perioperative complications associated with the use of dexmedetomidine during these challenging cases. With its anxiolytic, sedative, and analgesic properties coupled with preservation of respiration and a short half-life, dexmedetomidine has ideal properties for DBS procedures.

Deep brain stimulation complicated by bilateral large cystic cavitation around the leads in a patient with Parkinson's disease

Deep brain stimulation (DBS) is an approved and effective therapy for patients suffering from advanced Parkinson's disease (PD). Several clinical trials have indicated significant motor function improvement in patients undergoing subthalamic nucleus stimulation. This therapy is, rarely, associated with complications, mostly related to infections, seizures or stimulation-induced side effects. We report a case of a 71-year-old man with a 10-year history of PD who underwent bilateral placement of subthalamic nucleus DBS. As a complication, the patient showed subjective postoperative cognitive decline, and subsequent MRI showed peri-lead oedema, which progressed to large cystic cavitation around the leads without indication of infection. The patient received steroid therapy and the cavitations regressed without surgical intervention.

Neuromonitoring with microdialysis in severe traumatic brain injury patients

BACKGROUND

Neuromonitoring with microdialysis has the potential for early detection of metabolic derangements associated with TBI.

METHODS

1,260 microdialysis samples from 12 TBI patients were analyzed for glucose, -lactate, pyruvate, lactate/pyruvate ratio (LPR), and lactate/glucose ratio (LGR). Analytes were correlated with the Glasgow Coma Scale (GCS) before surgery and with the Glasgow Outcome Scale (GOS) at the time of discharge. The patients were divided into two groups for GCS: 3-6 and 7-9, and for GOS 1-3 and 4-5. Chi-squared test was performed for correlations.

RESULTS

Glucose, lactate levels, and LGR were high in TBI patients with GCS 3-6 (p < 0.0001). Pyruvate level was lower in patients with GCS 7-9 (p < 0.001). LPR was higher in patients with GCS 3-6 (p < 0.05). High glucose, lactate level (p < 0.001), and LPR (p < 0.01) was observed in patients with GOS 1-3. Pyruvate level was low in patients with GOS 1-3 (p < 0.001). LGR was higher in patient with better outcome (GOS 4-5).

CONCLUSION

After craniotomy extracellular glucose and lactate were good "biomarkers" of cerebral damage in TBI patients. We consider that high extracellular lactate and low glucose is an indicator of severe neurological damage and poor outcome, because of impaired brain metabolism.

Whole-brain proton MR spectroscopic imaging of mild-to-moderate traumatic brain injury and correlation with neuropsychological deficits

Changes in the distribution of the magnetic resonance (MR)-observable brain metabolites N-acetyl aspartate (NAA), total choline (Cho), and total creatine (Cre), following mild-to-moderate closed-head traumatic brain injury (mTBI) were evaluated using volumetric proton MR spectroscopic imaging (MRSI). Studies were carried out during the subacute time period following injury, and associations of metabolite indices with neuropsychological test (NPT) results were evaluated. Twenty-nine subjects with mTBI and Glasgow Coma Scale (GCS) scores of 10-15 were included. Differences in individual metabolite and metabolite ratio distributions relative to those of age-matched control subjects were evaluated, as well as analyses by hemispheric lobes and tissue types. Primary findings included a widespread decrease of NAA and NAA/Cre, and increases of Cho and Cho/NAA, within all lobes of the TBI subject group, and with the largest differences seen in white matter. Examination of the association between all of the metabolite measures and the NPT scores found the strongest negative correlations to occur in the frontal lobe and for Cho/NAA. No significant correlations were found between any of the MRSI or NPT measures and the GCS. These results demonstrate that significant and widespread alterations of brain metabolites occur as a result of mild-to-moderate TBI, and that these measures correlate with measures of cognitive performance.

Clinical Outcomes Using Modest Intravascular Hypothermia After Acute Cervical Spinal Cord Injury

BACKGROUND

Although a number of neuroprotective strategies have been tested after spinal cord injury (SCI), no treatments have been established as a standard of care.

OBJECTIVE

We report the clinical outcomes at 1-year median follow-up, using endovascular hypothermia after SCI and a detailed analysis of the complications.

METHODS

We performed a retrospective analysis of American Spinal Injury Association and International Medical Society of Paraplegia Impairment Scale (AIS) scores and complications in 14 patients with SCI presenting with a complete cervical SCI (AIS A). All patients were treated with 48 hours of modest (33°C) intravascular hypothermia. The comparison group was composed of 14 age- and injury-matched subjects treated at the same institution.

RESULTS

Six of the 14 cooled patients (42.8%) were incomplete at final follow-up (50.2 [9.7] weeks). Three patients improved to AIS B, 2 patients improved to AIS C, and 1 patient improved to AIS D. Complications were predominantly respiratory and infectious in nature. However, in the control group, a similar number of complications was observed. Adverse events such as coagulopathy, deep venous thrombosis, and pulmonary embolism were not seen in the patients undergoing hypothermia.

CONCLUSION

This study is the first phase 1 clinical trial on the safety and outcome with the use of endovascular hypothermia in the treatment of acute cervical SCI. In this small cohort of patients with SCI, complication rates were similar to those of normothermic patients with an associated AIS A conversion rate of 42.8%.

Outcomes and management strategies after nondiagnostic stereotactic biopsies of brain lesions

BACKGROUND/AIMS

A significant minority of stereotactic biopsies (SBs) of brain lesions is nondiagnostic, yet there are no optimal strategies for preventing nondiagnostic SB (NDSB) and for managing patients after NDSB. We performed this study in order to identify risk factors for NDSB, to determine how diagnoses are eventually reached in these patients, and to ascertain whether NDSB affects clinical outcomes.

METHODS

Retrospective chart review of patients at our institution who underwent SB of brain lesions.

RESULTS

Twenty-four out of 100 SBs were nondiagnostic. NDSB was less likely in contrast-enhancing brain lesions in immunocompetent patients, with larger lesions and in the setting of diagnostic findings on intraoperative frozen section analysis. Of 16 patients with adequate postoperative follow-up, a diagnosis was eventually reached in 11, via further review of the pathology, retrieval of additional tissue specimens or additional noninvasive testing. Survival times for patients with NDSB and eventual tumor diagnoses were within expected ranges for patients with similar tumors. Three of the 5 patients who never received a final diagnosis enjoyed prolonged survival without progressive symptoms.

CONCLUSIONS

Surgeons should consider taking additional specimens in the case of nondiagnostic intraoperative frozen section during SB. If a tumor is suspected and final pathology is nondiagnostic, outside review of the slides may be helpful, and sampling further tissue should be considered. For diseases other than tumors, the diagnosis will generally be made without a repeat biopsy. The delays in diagnosis resulting from NDSB do not appear to affect survival, at least in patients eventually found to have brain tumors.

Detrimental effects of systemic hyperthermia on locomotor function and histopathological outcome after traumatic spinal cord injury in the rat

OBJECTIVE

Posttraumatic hyperthermia has been demonstrated to worsen neurological outcome in models of brain injury. The purpose of this study was to examine the effects of systemic hyperthermia on locomotor and morphological outcome measures after traumatic spinal cord injury (SCI) in the rat.

METHODS

After a T10 laminectomy, spinal cord contusions were produced from a height of 12.5 mm onto exposed cords (NYU Impactor; New York University Neurosurgery Laboratory, New York, NY) in adult rats that were divided into three groups. Group 1 (n = 9) underwent whole body hyperthermia (rectal temperature, 39.5 degrees C) 30 minutes postinjury for 4 hours, Group 2 (n = 8) underwent normothermia (rectal temperature, 37 degrees C) 30 minutes postinjury for 4 hours, and Group 3 (n = 10) underwent traumatic SCI with no postinjury thermal treatment. Twice-weekly assessments of locomotor function were made during a 6-week survival period using the Basso-Beattie-Breshnahan locomotor rating scale. Forty-four days after injury, animals were perfused, and their spinal cords serially sectioned. Sections were stained with hematoxylin, eosin, and Luxol fast blue for histopathological analysis. The percentage of tissue damage was quantitatively determined by using computer-aided image analysis.

RESULTS

The results showed that 4 hours of postinjury hyperthermia significantly worsened locomotor outcome (final Basso-Beattie-Breshnahan scores were 9.7 +/- 0.3 [Group 1] versus 10.8 +/- 0.4 [Group 2] versus 11.3 +/- 0.3 [Group 3]) and led to an increase in the percentage of tissue damage (32.9 + 3.2% [Group 1] versus 22.3 +/- 2.8% [Group 3]).

CONCLUSION

These data suggest that complications of SCI (e.g., fever, infection) leading to an elevation of systemic temperature may add to the severity of secondary injury associated with traumatic SCI and significantly affect neurological outcome.

Induction of Eph B3 after spinal cord injury

Spinal cord injury (SCI) in adult rats initiates a cascade of events producing a nonpermissive environment for axonal regeneration. This nonfavorable environment could be due to the expression of repulsive factors. The Eph receptor protein tyrosine kinases and their respective ligands (ephrins) are families of molecules that play a major role in axonal pathfinding and target recognition during central nervous system (CNS) development. Their mechanism of action is mediated by repellent forces between receptor and ligand. The possible role that these molecules play after CNS trauma is unknown. We hypothesized that an increase in the expression of Eph proteins and/or ephrins may be one of the molecular cues that restrict axonal regeneration after SCI. Rats received a contusive SCI at T10 and in situ hybridization studies 7 days posttrauma demonstrated: (i) a marked up-regulation of Eph B3 mRNA in cells located in the white matter at the lesion epicenter, but not rostral or caudal to the injury site, and (ii) an increase in Eph B3 mRNA in neurons in the ventral horn and intermediate zone of the gray matter, rostral and caudal to the lesion. Immunohistochemical analyses localizing Eph B3 protein were consistent with the mRNA results. Colocalization studies performed in injured animals demonstrated increased Eph B3 expression in white matter astrocytes and motor neurons of the gray matter. These results suggest that Eph B3 may contribute to the unfavorable environment for axonal regeneration after SCI.