Surgical evacuation of acute subdural hematoma in octogenarians: a ten-year experience from a single trauma center.

BACKGROUND: Elderly patients presenting with an acute subdural hematoma (aSDH) have historically had unfavorable outcomes. METHODS: We retrospectively reviewed patient records from 2005 through 2015 that were ≥80 years of age and underwent surgical evacuation of aSDH. RESULTS: Thirty-four patients met inclusion criteria, with a mean age of 84 years (range 80-91). Glascow Outcome Scale (GOS) of 4-5 was deemed a good outcome and a GOS 1-3 was deemed to be a poor outcome. Six patients had good outcome at last follow up and 27 patients had poor outcome. Patients with a higher presenting Glascow Coma Scale (GCS) trended towards better outcome [(good: mean 13.1, median 14.5, IQR 12.5-15) vs. (poor: mean 9.6, median 10, IQR 6-14) p = 0.06]. Patients with a higher in-hospital post-operative GCS score had significantly better overall outcome than patients who left the hospital with a lower GCS score [(good: mean 14.5, median 14.5, IQR 14-15) vs. (poor: mean 8.4, median 9, IQR 4-11) p = 0.001]. Patients with a good outcome had a median aSDH thickness of 17mm (IQR 12.75-19.75) while patients with a poor outcome had a median thickness of 20mm (IQR 16-24.5); p = 0.17. In addition, patients with a good outcome had a median midline shift of 10mm (IQR 6-12.5), while patients with a poor outcome had a median midline shift of 14mm (IQR 10-20); p = 0.07. CONCLUSIONS: The prognosis for elderly patients with large aSDH remains poor, but a subset of patients can benefit from surgical intervention.

Older Stroke Patients with High Stroke Scores Have Delayed Door-To-Needle Times.

INTRODUCTION: The timely administration of intravenous (IV) tissue plasminogen activator (t-PA) to acute ischemic stroke patients from the period of symptom presentation to treatment, door-to-needle (DTN) time, is an important focus for quality improvement and best clinical practice. METHODS: A retrospective review of our Get With The Guidelines database was performed for a 5-hospital telestroke network for the period between January 2010 and January 2015. All acute ischemic stroke patients who were triaged in the emergency departments connected to the telestroke network and received IV t-PA were included. Optimal DTN time was defined as less than 60 minutes. Logistic regression was performed with clinical variables associated with DTN time. Age and National Institutes of Health Stroke Scale (NIHSS) score were categorized based on clinically significant cutoffs. RESULTS: Six-hundred and fifty-two patients (51% women, 46% White, 45% Hispanic, and 8% Black) were included in this study. The mean age was 70 years (range 29-98). Of the variables analyzed, only arrival mode, initial NIHSS score, and the interaction between age and initial NIHSS score were significant. DTN time more than or equal to 60 minutes was most common in patients aged more than 80 years with NIHSS score higher than 10. CONCLUSIONS: The cause of DTN time delay for older patients with higher NIHSS score is unclear but was not related to presenting blood pressure or arrival mode. Further study of this subgroup is important to reduce overall DTN times.

Prenatal betamethasone exposure has sex specific effects in reversal learning and attention in juvenile baboons.

OBJECTIVE: We investigated effects of 3 weekly courses of fetal betamethasone (ßM) on motivation and cognition in juvenile baboon offspring utilizing the Cambridge Neuropsychological Test Automated Battery. STUDY DESIGN: Pregnant baboons (Papio species) received 2 injections of saline control or 175 µg/kg ßM 24 hours apart at 0.6, 0.65, and 0.7 gestation. Offspring (saline control female, n = 7 and saline control male, n = 6; ßM female [FßM], n = 7 and ßM male [MßM], n = 5) were studied at 2.6-3.2 years with a progressive ratio test for motivation, simple discriminations and reversals for associative learning and rule change plasticity, and an intra/extradimensional set-shifting test for attention allocation. RESULTS: ßM exposure decreased motivation in both sexes. In intra/extradimensional testing, FßM made more errors in the simple discrimination reversal (mean difference of errors [FßM - MßM] = 20.2 ± 9.9; P ≤ .05), compound discrimination (mean difference of errors = 36.3 ± 17.4; P ≤ .05), and compound reversal (mean difference of errors = 58 ± 23.6; P < .05) stages as compared to the MßM offspring. CONCLUSION: This central nervous system developmental programming adds growing concerns of long-term effects of repeated fetal synthetic glucocorticoid exposure. In summary, behavioral effects observed show sex-specific differences in resilience to multiple fetal ßM exposures.

Differences in performance between Sprague-Dawley and Fischer 344 rats in positive reinforcement tasks.

This experimental investigation tested two different strains of rat, Sprague-Dawley (SD) and Fischer 344 (F344), in their ability to learn lever pressing for food (autoshaping) or intracranial self-administration (ICSA) of dextroamphetamine (AMPH) into the nucleus accumbens (NAcc). Additionally, a unique method of intracranial drug delivery was utilized, via reverse dialysis, by the use of a microdiaylsis probe. The experiments revealed definite behavioral differences between SD and F344 animals. The autoshaping data indicated that SD rats, on average, acquired lever pressing for food in fewer training days than F344 rats. Also, the ICSA experiment revealed that SD rats self-administered AMPH at a 30 mug/mul concentration. Lever pressing was significantly greater in those SD rats receiving AMPH than in the F344 drug group. Furthermore, the F344 rats never acquired lever pressing for intra-NAcc delivery of AMPH under our testing regime. These data reveal differences in performance of positively reinforced operant tasks between the inbred F344 rats as compared to the outbred SD strain.

Correction: The impact of tackle football injuries on the American healthcare system with a neurological focus.

[This corrects the article DOI: 10.1371/journal.pone.0195827.].

The impact of tackle football injuries on the American healthcare system with a neurological focus.

BACKGROUND: Recent interest in the study of concussion and other neurological injuries has heightened awareness of the medical implications of American tackle football injuries amongst the public. OBJECTIVE: Using the National Emergency Department Sample (NEDS) and the National Inpatient Sample (NIS), the largest publicly available all-payer emergency department and inpatient healthcare databases in the United States, we sought to describe the impact of tackle football injuries on the American healthcare system by delineating injuries, specifically neurological in nature, suffered as a consequence of tackle football between 2010 and 2013. METHODS: The NEDS and NIS databases were queried to collect data on all patients presented to the emergency department (ED) and/or were admitted to hospitals with an ICD code for injuries related to American tackle football between the years 2010 and 2013. Subsequently those with football-related neurological injuries were abstracted using ICD codes for concussion, skull/face injury, intracranial injury, spine injury, and spinal cord injury (SCI). Patient demographics, length of hospital stay (LOS), cost and charge data, neurosurgical interventions, hospital type, and disposition were collected and analyzed. RESULTS: A total of 819,000 patients presented to EDs for evaluation of injuries secondary to American tackle football between 2010 and 2013, with 1.13% having injuries requiring inpatient admission (average length of stay 2.4 days). 80.4% of the ED visits were from the pediatric population. Of note, a statistically significant increase in the number of pediatric concussions over time was demonstrated (OR = 1.1, 95% CI 1.1 to 1.2). Patients were more likely to be admitted to trauma centers, teaching hospitals, the south or west regions, or with private insurance. There were 471 spinal cord injuries and 1,908 total spine injuries. Ten patients died during the study time period. The combined ED and inpatient charges were $1.35 billion. CONCLUSION: Injuries related to tackle football are a frequent cause of emergency room visits, specifically in the pediatric population, but severe acute trauma requiring inpatient admission or operative interventions are rare. Continued investigation in the long-term health impact of football related concussion and other repetitive lower impact trauma is warranted.

Data Sharing in Neurosurgery and Neurology Journals.

In this era of high health care cost and limited research resources, open access to de-identified clinical research study data may promote increased scientific transparency and rigor, allow for the combination and re-analysis of similar data sets, and decrease un-necessary replication of unpublished negative studies. Driven by expanded computing capabilities, advocacy for data sharing to maximize research value is growing in both translational and clinical research communities. The focus of this study is to report on the current status of publicly available research data from studies published in the top 40 neurology and neurosurgery clinical research journals by impact factor. The top journals were carefully reviewed for data sharing policies. Of the journals with data sharing policies, the 10 most current original research papers from December 2015 - February 2016 were reviewed for data sharing statements and data availability. A data sharing policy existed for 48% (19/40) of the 40 journals investigated. Of the 19 journals with an existing data sharing policy, 58% (11/19) of the policies stated that data should be made available to interested parties upon request and 21% (4/19) of these journals encouraged authors to provide a data sharing statement in the article of what data would be available upon request. Of the 190 articles reviewed for data availability, 21% (40/190) of these articles included some source data in the results, figures, or supplementary sections. This evaluation highlights opportunities for neurology and neurosurgery investigators and journals to improve access to study data and even publish the data prospectively for the betterment of clinical outcome analysis and patient care.

Limitations of multidetector computed tomography angiography for the diagnosis of blunt cerebrovascular injury.

OBJECTIVE Blunt cerebrovascular injuries (BCVIs) following trauma carry risk for morbidity and mortality. Since patients with BCVI are often asymptomatic at presentation and neurological sequelae often occur within 72 hours, timely diagnosis is essential. Multidetector CT angiography (CTA) has been shown to be a noninvasive, cost-effective, reliable means of screening; however, the false-positive rate of CTA in diagnosing patients with BCVI represents a key drawback. Therefore, the authors assessed the role of DSA in the screening of BCVI when utilizing CTA as the initial screening modality. METHODS The authors performed a retrospective analysis of patients who experienced BCVI between 2013 and 2015 at 2 Level I trauma centers. All patients underwent CTA screening for BCVI according to the updated Denver Screening Criteria. Patients who were diagnosed with BCVI on CTA underwent confirmatory digital subtraction angiography (DSA). Patient demographics, screening indication, BCVI grade on CTA and DSA, and laboratory values were collected. Comparison of false-positive rates stratified by BCVI grade on CTA was performed using the chi-square test. RESULTS A total of 140 patients (64% males, mean age 50 years) with 156 cerebrovascular blunt injuries to the carotid and/or vertebral arteries were identified. After comparison with DSA findings, CTA findings were incorrect in 61.5% of vessels studied, and the overall CTA false-positive rates were 47.4% of vessels studied and 47.9% of patients screened. The positive predictive value (PPV) for CTA was higher among worse BCVI subtypes on initial imaging (PPV 76% and 97%, for BCVI Grades II and IV, respectively) compared with Grade I injuries (PPV 30%, p < 0.001). CONCLUSIONS In the current series, multidetector CTA as a screening test for blunt cerebrovascular injury had a high-false positive rate, especially in patients with Grade I BCVI. Given a false-positive rate of 47.9% with an estimated average of 132 patients per year screening positive for BCVI with CTA, approximately 63 patients per year would potentially be treated unnecessarily with antithrombotic therapy at a busy United States Level I trauma center. The authors' data support the use of DSA after positive findings on CTA in patients with suspected BCVI. DSA as an adjunctive test in patients with positive CTA findings allows for increased diagnostic accuracy in correctly diagnosing BCVI while minimizing risk from unnecessary antithrombotic therapy in polytrauma patients.

JWH-018 in rhesus monkeys: differential antagonism of discriminative stimulus, rate-decreasing, and hypothermic effects.

Several effects of the abused synthetic cannabinoid JWH-018 were compared to those of Δ9-tetrahydrocannabinol (Δ9-THC) in rhesus monkeys. JWH-018 (0.1 mg/kg i.v.) was established as a discriminative stimulus and rimonabant was used to examine mechanisms responsible for discrimination as well as operant response rate-decreasing and hypothermic effects. JWH-018 dose-dependently increased drug-lever responding (ED50=0.01 mg/kg) and decreased response rate (ED50=0.064 mg/kg). Among various cannabinoids, the relative potency for producing discriminative stimulus and rate-decreasing effects was the same: CP-55940=JWH-018>Δ9-THC=WIN-55212-2=JWH-073. The benzodiazepine agonist midazolam and the NMDA antagonist ketamine did not exert JWH-018 like discriminative stimulus effects up to doses that disrupted responding. JWH-018 and Δ9-THC decreased rectal temperature by 2.2 and 2.8°C, respectively; the doses decreasing temperature by 2°C were 0.21 and 1.14 mg/kg, respectively. Antagonism did not differ between JWH-018 and Δ9-THC, but did differ among effects. The apparent affinities of rimonabant calculated in the presence of JWH-018 and Δ9-THC were not different from each other for antagonism of discriminative stimulus effects (6.58 and 6.59, respectively) or hypothermic effects (7.08 and 7.19, respectively). Apparent affinity estimates are consistent with the same receptors mediating the discriminative stimulus and hypothermic effects of both JWH-018 and Δ9-THC. However, there was more limited and less orderly antagonism of rate-decreasing effects, suggesting that an additional receptor mechanism is involved in mediating the effects of cannabinoids on response rate. Overall, these results strongly suggest that JWH-018 and Δ9-THC act at the same receptors to produce several of their shared psychopharmacological effects.

Discriminative stimulus and hypothermic effects of some derivatives of the nAChR agonist epibatidine in mice.

RATIONALE: Receptor mechanisms underlying the in vivo effects of nicotinic acetylcholine receptor (nAChR) drugs need to be determined to better understand possible differences in therapeutic potential. OBJECTIVE: This study compared the effects of agonists that are reported either to differ in intrinsic activity (i.e., efficacy) at α4ß2 nAChR in vitro or to have in vivo effects consistent with differences in efficacy. The drugs included nicotine, varenicline, cytisine, epibatidine, and three novel epibatidine derivatives: 2'-fluoro-3'-(4-nitrophenyl)deschloroepibatidine (RTI-7527-102), 2'-fluorodeschloroepibatidine (RTI-7527-36), and 3'-(3″-dimethylaminophenyl)-epibatidine (RTI-7527-76). METHODS: Mice discriminated nicotine base (1 mg/kg base) from saline; other mice were used to measure rectal temperature. RESULTS: In the nicotine discrimination assay, the maximum percentage of nicotine-appropriate responding varied: 92 % for nicotine, 84 % for epibatidine, 77 % for RTI-7527-36, and 71 % for varenicline and significantly less for RTI-7527-76 (58 %), RTI-7527-102 (46 %), and cytisine (33 %). Each drug markedly decreased rectal temperature by as much as 12 ºC. The rank-order potency in the discrimination and hypothermia assays was epibatidine > RTI-7527-36 > nicotine > RTI-7527-102 > varenicline = cytisine = RTI-7527-76. The nAChR antagonist mecamylamine (3.2 mg/kg) antagonized the discriminative stimulus effects of epibatidine and RTI-7527-102, as well as the hypothermic effects of every drug except cytisine. The ß2-subunit selective nAChR antagonist dihydro-ß-erythroidine (DHßE; up to 10 mg/kg) antagonized hypothermic effects but less effectively so than mecamylamine. CONCLUSIONS: The marked hypothermic effects of all drugs except cytisine are due in part to agonism at nAChR containing ß2-subunits. Differential substitution for the nicotine discriminative stimulus is consistent with differences in α4ß2 nAChR efficacy; however, collectively the current results suggest that multiple nAChR receptor subtypes mediate the effects of the agonists.

Poor nutrition during pregnancy and lactation negatively affects neurodevelopment of the offspring: evidence from a translational primate model.

BACKGROUND: Studies of the effects of prenatal nutrition on neurodevelopment in humans are complicated because poor nutrition occurs in the context of psychosocial stressors and other risk factors associated with poor developmental outcomes. OBJECTIVE: Under controlled experimental conditions, we tested an effect of prenatal nutrition on neurodevelopmental outcomes in the nonhuman primate. DESIGN: Juvenile offspring of 19 female baboons, whose diets were either restricted [maternal nutrition restriction (MNR)] or who were fed ad libitum (control), were administered the progressive ratio task from the Cambridge Neuropsychological Test Automated Battery. Activity, persistence, attention, and emotional arousal were coded from videotapes. These established, reliable methods were consistent with those used to assess individual differences in the behaviors of school-age children. RESULTS: MNR offspring (3 female and 4 male offspring) had significantly fewer responses and received fewer reinforcements on the progressive ratio task than did control offspring (8 female and 4 male offspring). MNR offspring showed a more variable activity level and less emotional arousal than did control offspring. Female MNR offspring showed more variable and lower levels of persistence and attention than did female control offspring. Thus, under controlled experimental conditions, data support a main effect of prenatal nutrition on highly translatable neurodevelopmental outcomes. CONCLUSIONS: Nutritional interventions during pregnancy have been successfully used to target neurodevelopmental problems, such as increasing folic acid intake during pregnancy to decrease the incidence of neural tube defects. Results from the current study can be used to support the testing of nutritional preventive interventions for the most-common childhood behavior problems.

Sex-dependent cognitive performance in baboon offspring following maternal caloric restriction in pregnancy and lactation.

In humans a suboptimal diet during development has negative outcomes in offspring. We investigated the behavioral outcomes in baboons born to mothers undergoing moderate maternal nutrient restriction (MNR). Maternal nutrient restriction mothers (n = 7) were fed 70% of food eaten by controls (CTR, n = 12) fed ad libitum throughout gestation and lactation. At 3.3 ± 0.2 (mean ± standard error of the mean [SEM]) years of age offspring (controls: female [FC, n = 8], male [MC, n = 4]; nutrient restricted: female [FR, n = 3] and male [MR, n = 4]) were administered progressive ratio, simple discrimination, intra-/extra-dimension set shift and delayed matching to sample tasks to assess motivation, learning, attention, and working memory, respectively. A treatment effect was observed in MNR offspring who demonstrated less motivation and impaired working memory. Nutrient-restricted female offspring showed improved learning, while MR offspring showed impaired learning and attentional set shifting and increased impulsivity. In summary, 30% restriction in maternal caloric intake has long lasting neurobehavioral outcomes in adolescent male baboon offspring.

CANTAB delayed matching to sample task performance in juvenile baboons.

This study reports the administration of the Cambridge Neuropsychological Test Automated Battery system's delayed matching to sample (DMTS) task to juvenile baboons. Nine subjects (female=5, male=4) were trained with delay intervals ranging from 0 to 80s. Trial unique stimuli were utilized in combination with matching to sample, in contrast to non-matching to sample, to more accurately assess components of medial temporal lobe (hippocampal formation) mediated working memory. These parameters force subjects to rely on recognition for matching stimuli and overcome their innate tendency to choose novel stimuli (non-matching), thus increasing task difficulty. Testing with delays intervals of 0-2, 4, 8, and 16s revealed decreased percent correct responding as delay intervals increased. An effect of 1 vs. 3 distractor stimuli on accuracy was also noted. Increasing the number of distractors resulted in decreased observing response latencies. The increase in choice response latency seen with increasing delay interval was independent of number of distractor stimuli presented. There were no sex differences in task performance. Our laboratory is focused on understanding the functional consequences of suboptimal conditions during pregnancy and early postnatal life in offspring. The ability of juvenile baboons to perform the DMTS task demonstrates the utility of this non-human primate model in examining pre- and post-natal conditions that impact the development of working memory. Evaluation of causes and consequences of impaired working memory in a variety of human diseases will be assisted by the use of this task in nonhuman primate models of human health and disease.

Local pretreatment with the cannabinoid CB1 receptor antagonist AM251 attenuates methamphetamine intra-accumbens self-administration.

The endocannabinoid system is a potential target for therapeutic intervention of substance abuse. Cannabinoid CB1 receptor antagonist decreases intravenous methamphetamine self-administration in animal models. This study examined whether the nucleus accumbens (NAcc) is a site of interaction between methamphetamine and the CB1 receptor antagonist AM251. Male Sprague-Dawley rats were trained to lever press and then were surgically implanted with a guide cannula into the right NAcc. Rats were allowed one week to recover and then AM251 (0.1 or 1.0 µg/µL) was reverse dialyzed directly into the NAcc prior to methamphetamine (10 µg/µL) intra-accumbens self-administration. AM251 (1.0 µg/µL) reduced methamphetamine self-administration while AM251 (0.1 µg/µL) had an intermediary effect. The mechanism of self-administration attenuation is not known but could be mediated by AM251 affecting the negative feedback from the NAcc to the ventral tegmental area (VTA). This study provides evidence that the endocannabinoid system is involved with rewarding effects of methamphetamine and suggests a possible therapeutic intervention for methamphetamine abuse.

Performance of juvenile baboons on neuropsychological tests assessing associative learning, motivation and attention.

The CANTAB (Cambridge Neuropsychological Test Automated Battery), a system developed for human neuropsychological testing, has previously been used to assess cognitive function in two species of nonhuman primates, common marmoset monkeys and rhesus macaques. We describe the application of the system to the juvenile baboon, a nonhuman primate species offering specific investigative advantages. Juvenile baboons were trained and tested on a progressive ratio task to assess motivation, simple discrimination and simple reversal tasks to assess associative learning, and intra- and extra-dimensional set-shifting tasks to assess selective attention and attentional set-shifting, respectively. Study subjects were 8 juvenile baboons (Papio sp.), 4 females and 4 males aged 3.0+/-0.1 (mean+SEM) years and weight 8.2+/-0.4 kg. All baboons were easily trained, readily learned the neuropsychological tests and exhibited a stable performance. Applying a method such as the CANTAB has significant implications for expanding on the translational utility of the baboon in studies of neurodevelopment.