Neurovascular effects of cocaine: relevance to addiction.

Cocaine is a highly addictive drug, and its use is associated with adverse medical consequences such as cerebrovascular accidents that result in debilitating neurological complications. Indeed, brain imaging studies have reported severe reductions in cerebral blood flow (CBF) in cocaine misusers when compared to the brains of healthy non-drug using controls. Such CBF deficits are likely to disrupt neuro-vascular interaction and contribute to changes in brain function. This review aims to provide an overview of cocaine-induced CBF changes and its implication to brain function and to cocaine addiction, including its effects on tissue metabolism and neuronal activity. Finally, we discuss implications for future research, including targeted pharmacological interventions and neuromodulation to limit cocaine use and mitigate the negative impacts.

A double-hit: End-stage renal disease patients suffer worse outcomes in intracerebral hemorrhage.

BACKGROUND: Intracerebral hemorrhage (ICH) carries significant morbidity and mortality. Previous single-center retrospective analysis suggests that end-stage renal disease (ESRD) is a risk factor for severe ICH and worse outcomes. This investigation aims to examine the impact of ESRD on ICH severity, complications, and outcomes using a multicenter national database. METHODS: The International Classification of Disease, Ninth and Tenth Revision Clinical Modification codes were used to query the National Inpatient Sample for patients with ICH and ESRD between 2010 and 2019. Primary endpoints were the functional outcome, length of stay (LOS), and in-hospital mortality. Multivariate variable regression models and a propensity-score matched analysis were established to analyze patient outcomes associated with baseline patient characteristics. RESULTS: We identified 211,266 patients with ICH, and among them, 7,864 (3.77%) patients had a concurrent diagnosis of ESRD. Patients with ESRD were younger (60.85 vs. 67.64, P < 0.01) and demonstrated increased ICH severity (0.78 vs. 0.77, P < 0.01). ESRD patients experienced higher rates of sepsis (15.9% vs. 6.15%, P < 0.01), acute myocardial infarction (8.05% vs. 3.65%, P < 0.01), and cardiac arrest (5.94% vs. 2.4%, P < 0.01). In addition, ESRD predicted poor discharge disposition (odds ratio [OR]: 2.385, 95% confidence interval [CI]: 2.227-2.555, P < 0.01), longer hospital LOS (OR: 1.629, 95% CI: 1.553-1.709, P < 0.01), and in-hospital mortality (OR: 2.786, 95% CI: 2.647-2.932, P < 0.01). CONCLUSIONS: This study utilizes a multicenter database to analyze the effect of ESRD on ICH outcomes. ESRD is a significant predictor of poor functional outcomes, in-hospital mortality, and prolonged stay in the ICH population.

Effect of chronic antiplatelet therapy on clinical outcomes of endovascular thrombectomy for treatment of acute ischemic stroke.

OBJECTIVE: The objective of this study was to investigate the prognostic significance of chronic antiplatelet therapy (APT) usage in acute ischemic stroke (AIS) treated with endovascular thrombectomy (EVT). Long-term APT may enhance recanalization but may also predispose patients to an increased risk of hemorrhagic transformation. METHODS: Weighted hospitalizations for anterior-circulation AIS treated with EVT were identified in a large United States claims-based registry. Baseline clinical characteristics and outcomes were compared between patients with and without chronic APT usage prior to admission. Multivariable logistic regression analysis was performed to assess adjusted associations between APT and study endpoints. RESULTS: This analysis identified 36,560 patients, of whom 8170 (22.3%) were on a chronic APT regimen prior to admission. These patients were older and demonstrated a higher burden of comorbid disease, but had similar stroke severity on presentation in comparison with those not on APT. On unadjusted analysis, patients with prior APT demonstrated higher rates of favorable outcomes (24.3% vs 21.5%, p < 0.001), lower rates of mortality (7.0% vs 10.1%, p < 0.001), and lower rates of any intracranial hemorrhage (ICH; 20.3% vs 24.2%, p < 0.001), but no difference in rates of symptomatic ICH (sICH). Following multivariable adjustment for baseline clinical characteristics including age, acute stroke severity, and comorbidity burden, prior APT was associated with favorable outcome (adjusted odds ratio [aOR] 1.21, 95% CI 1.17-1.24, p < 0.001) and a lower likelihood of mortality (aOR 0.73, 95% CI 0.70-0.77, p < 0.001), without an increased likelihood of ICH (any ICH aOR 0.84, 95% CI 0.81-0.87, p < 0.001; sICH aOR 0.92, 95% CI 0.82-1.03, p = 0.131). CONCLUSIONS: Retrospective evaluation of patients with AIS treated with EVT using registry-based data demonstrated an association of prior APT usage with favorable outcomes, without an increased risk of hemorrhagic transformation.

Incidence, Characteristics, and Outcomes of Stroke in Pediatric Patients with Celiac Disease.

(1) Background: Celiac disease (CD) can cause long-term inflammation and endothelial dysfunction and has been cited as a risk factor for acute ischemic stroke (AIS) in pediatric patients. However, the rate and outcomes of AIS in pediatric patients with CD has not been explored in a large population. Our objective is to explore the rate, severity, and outcomes of CD amongst pediatric AIS patients on a nationwide level. (2) Methods: The National Inpatient Sample (NIS) database was queried from 2016 to 2020 for pediatric patients with a principal diagnosis of AIS. Patients with a concurrent diagnosis of CD (AIS-CD) were compared to those without (AIS). Baseline demographics and comorbidities, clinical variables of severity, hospital complications, and the rates of tissue plasminogen activator (tPA) and mechanical thrombectomy were compared between the two groups. The main outcomes studied were mortality, discharge disposition, length of stay (LOS), and total hospital charges. (3) Results: Of 12,755 pediatric patients with a principal diagnosis of AIS, 75 (0.6%) had concurrent CD. There were no differences in the severity, discharge disposition, or mortality between the AIS-CD and AIS patients. Patients with AIS-CD were more likely to receive tPA at an outside hospital within 24 h of admission (p < 0.01) and more likely to undergo mechanical thrombectomy (p < 0.01) compared to the AIS patients. (4) Conclusions: CD patients made up only 0.6% of all pediatric AIS patients. No differences in the severity, mortality, or discharge disposition suggests a minimal to absent role of CD in the etiology of stroke. The CD-AIS patients were more likely to receive a tPA or undergo a mechanical thrombectomy; studies are needed to confirm the safety and efficacy of these interventions in pediatric patients.

Aneurysmal Subarachnoid Hemorrhage and Cardiac Related Fatality: Who Dies and Why?

Medical complications are a notable source of in-hospital death following aneurysmal subarachnoid hemorrhage (aSAH). However, there is a paucity of literature examining medical complications on a national scale. This study uses a national dataset to analyze the incidence rates, case fatality rates, and risk factors for in-hospital complications and mortality following aSAH. We found that the most common complications in aSAH patients (N = 170, 869) were hydrocephalus (29.3%) and hyponatremia (17.3%). Cardiac arrest was the most common cardiac complication (3.2%) and was associated with the highest case fatality rate overall (82%). Patients with cardiac arrest also had the highest odds of in-hospital mortality [odds ratio (OR), 22.92; 95% confidence interval (CI), 19.24-27.30; P < 0.0001], followed by patients with cardiogenic shock (OR, 2.96; 95% CI, 2.146-4.07; P < 0.0001). Advanced age and National Inpatient Sample-SAH Severity Score were found to be associated with an increased risk of in-hospital mortality (OR, 1.03; 95% CI, 1.03-1.03; P < 0.0001 and OR, 1.70; 95% CI, 1.65-1.75; P < 0.0001, respectively). Renal and cardiac complications are significant factors to consider in aSAH management, with cardiac arrest being the strongest indicator of case fatality and in-hospital mortality. Further research is needed to characterize factors that have contributed to the decreasing trend in case fatality rates identified for certain complications.

Significant increase in mortality and risk of acute ischemic stroke in infective endocarditis patients with subarachnoid hemorrhage secondary to mycotic aneurysms.

Infective Endocarditis (IE) patients are known to have a variety of complications with one of the rarest, but serious being cerebral mycotic aneurysm, which can result in subarachnoid hemorrhage (SAH). Using the National In-Patient Sample database, we sought to determine the rate of acute ischemic stroke (AIS) and outcomes in IE- patients with and without SAH. In total, we identified 82,844 IE-patients from 2010 to 2016, of which 641 had a concurrent diagnosis of SAH. IE patients with SAH had a more complicated course, higher mortality rate (OR 4.65 CI 95% 3.9-5.5, P < 0.001), and worse outcomes. This patient population also had a significantly higher rate of AIS (OR 6.3 CI 95% 5.4-7.4, P < 0.001). Overall, 41.5% of IE-patients with SAH had AIS during their hospitalization as compared to 10.1% of IE only patients. IE-patients with SAH were more likely to undergo endovascular treatment (3.6%) with 0.8% of the IE patients with AIS undergoing mechanical thrombectomy. While IE-patients are at risk for various complications, our study suggests a significant increase in the mortality and risk of AIS in those with SAH.

Early tracheostomy in patients undergoing mechanical thrombectomy for acute ischemic stroke.

PURPOSE: Respiratory failure following mechanical thrombectomy (MT) for acute ischemic stroke (AIS) is a known complication, and requirement of tracheostomy is associated with worse outcomes. Our objective is to evaluate characteristics associated with tracheostomy timing in AIS patients treated with MT. METHODS: The National Inpatient Sample was queried for adult patients treated with MT for AIS from 2016 to 2019. Baseline demographic characteristics, comorbidities, and inpatient outcomes were analyzed for associations in patients who received tracheostomy. Timing of early tracheostomy (ETR) was defined as placement before day 8 of hospital stay. RESULTS: Of 3505 AIS-MT patients who received tracheostomy, 915 (26.1%) underwent ETR. Patients who underwent ETR had shorter length of stay (LOS) (25.39 days vs 32.43 days, p < 0.001) and lower total hospital charges ($483,472.07 vs $612,362.86, p < 0.001). ETR did not confer a mortality benefit but was associated with less acute kidney injury (OR, 0.697; p = 0.013), pneumonia (OR, 0.449; p < 0.001), and sepsis (OR, 0.536; p = 0.002). CONCLUSION: An expected increase in complications and healthcare resource utilization is seen in AIS-MT patients receiving tracheostomy, likely reflecting the severity of patients' post-stroke neurologic injury. Among these high-risk patients, ETR was predictive of shorter LOS and fewer complications.

The gut-brain connection: Inflammatory bowel disease increases risk of acute ischemic stroke.

OBJECTIVES: Chronic inflammation of the gastrointestinal tract is a hallmark of inflammatory bowel disease (IBD). This increased inflammation is thought to induce a hypercoagulable state that increases the risk for stroke. However, few studies have examined the association between IBD and acute ischemic stroke (AIS). Thus, this study aims to investigate the incidence, treatments, complications, and outcomes of AIS in patients with IBD. MATERIALS & METHODS: ICD-9-CM and ICD-10-CM codes were used to query the National Inpatient Sample for AIS and IBD diagnosis. Baseline demographics, clinical characteristics, complications, treatments, and outcomes were assessed through descriptive statistics, multivariate regression, and propensity score matching (PSM) analysis. Acute stroke severity was assessed using the National Institute of Heath's Stroke Severity Score (SSS) as a template. RESULTS: 1,609,817 patients were diagnosed with AIS between 2010 through 2019. 7468 (0.46%) had concomitant diagnoses of IBD. AIS patients with IBS were younger, more likely to be white and female, but less likely to be obese. Although IBD patients had comparable stroke severities (p = 0.64) to their non-IBS counterparts, they received stroke intervention at statistically different rates than their non-IBD counterparts. Additionally, IBD patients had higher rates of in-hospital complications (p < 0.01) and longer lengths of stay (LOS) (p < 0.01). CONCLUSIONS: IBD patients develop AIS at a younger age with similar rates of stroke severity to their non-IBD counterparts, but receive higher rates of tissue plasminogen activator administration and decreased rates of mechanical thrombectomy. Our research shows that patients with IBD are at risk for AIS at an earlier age and are more likely to have complications. This underlies a connection between IBD and a hypercoagulable state that could predispose patients to AIS.

Ruptured arteriovenous malformation mortality: Incidence, risk factors, and inpatient outcome score.

BACKGROUND: Limited literature exists on the morbidity and mortality of AVM associated intracerebral hemorrhage (ICH) compared with non-AVM ICH. OBJECTIVE: We examine morbidity and mortality in cAVM in a large nationwide inpatient sample to create a prognostic inpatient ruptured AVM mortality score. METHODS: This retrospective cohort study from 2008 to 2014 compares outcomes in cAVM related hemorrhages and ICH utilizing the National Inpatient Sample database. Diagnostic codes for ICH and AVM underlying ICH were identified. We compared case fatality according to medical complications. Multivariate analysis was used to derive hazard ratios and 95% confidence intervals to assess odds of mortality. RESULTS: We identified 6496 patients with ruptured AVMs comparing them to 627,185 admitted with ICH. Mortality was lower for ruptured AVMs (11%) compared to ICH (22%) [p < 0.01]. Mortality associated factors were liver disease (OR 2.64, CI 1.81-3.85, p < .001), diabetes mellitus (OR 2.42, CI 1.38-4.22, p = 0.002), alcohol abuse (OR 1.81, CI 1.31-2.49, p = 0.001), hydrocephalus (OR 3.35 CI 2.81-4.00, p < 0.001), cerebral edema (OR 1.5, 1.25-1.85, p < 0.001), cardiac arrest (OR 15, CI 7.9-30, p < 0.001), and pneumonia (OR 1.93, CI 1.51-2.47, p < 0.001). A 0-5 ruptured AVM mortality score was developed: Cardiac arrest (=3), age >60 (=1), Black race (=1), chronic liver failure (=1) diabetes mellitus (=1), pneumonia (=1), alcohol abuse (=1) and cerebral edema (=1). Mortality increased with score. No patient with 5 or more points survived. CONCLUSION: The Ruptured AVM Mortality Score allows for risk stratification on patients with ICH due to ruptured AVM. This scale could prove useful in prognostication and patient education.

Complication Rates Following Cerebral and Coronary Angiography: Nationwide Analysis 2008-2014.

Catheter-based angiography is an essential procedure for the diagnosis and treatment of vascular complications in patients. Since cerebral and coronary angiography are similar techniques that utilize the same access sites and general principles, the associated risks overlap and should be identified to help direct patient care. The purpose of this study was to determine complication rates in a combined cohort of cerebral and coronary angiography patients, as well as conduct a comparative analysis of coronary and cerebral angiography complications. The National Inpatient Sample was queried from 2008 to 2014 to identify patients who underwent coronary or cerebral angiography. After assessment of baseline characteristics, complication rates, and disposition in the combined cohort, propensity matching was utilized to create sub-cohorts of coronary and cerebral angiography patients based on demographics and comorbidities. Comparative analysis of procedural complications and disposition was then performed. A total of 3,763,651 hospitalizations were included in our study cohort (3,505,715 coronary angiographies and 257,936 cerebral angiographies). The median age was 62.9 years, with females being 46.42%. The most prevalent comorbidities in the overall cohort were hypertension (69.92%), coronary artery disease (69.48%), smoking (35.64%), and diabetes mellitus (35.13%). Propensity matching demonstrated that the cerebral angiography cohort had lower rates of acute and unspecified renal failure (5.4% vs 9.2%, OR 0.57, 95% CI, 0.53-0.61, P < 0.001), hemorrhage/hematoma formation (0.8% vs 1.3%, OR 0.63, 95% CI, 0.54-0.73, P < 0.001), and equivalent rates of retroperitoneum hematoma formation (0.03% vs 0.04%, OR 1.49, 95% CI, 0.76-2.90, P = 0.247) and arterial embolism/ thrombus formation (0.3% vs 0.3%, OR 1.01, 95% CI, 0.81-1.27, P = 0.900). Our study showed both cerebral and coronary angiography have generally low rates of procedural complications. Matched cohort analysis demonstrated that cerebral angiography patients are at no greater risk for complications than coronary angiography patients.

Acute ischemic strokes in patients with developmental disabilities: A cross-sectional analysis.

OBJECTIVE: Patients with developmental disabilities (DD) are frequently excluded from acute ischemic stroke (AIS) randomized control trials. We sought to evaluate the impact of having DD on this patient cohort. METHODS: The National Inpatient Sample was analyzed to explore the impact of AIS and treatment on discharge dispositions in patients with DD. Clinical characteristics, treatments, and outcomes were compared to fully-abled patients with AIS. RESULTS: 1,605,723 patients with AIS were identified from 2010-2019, of whom 4094 (0.30%) had a DD. AIS patients with DD were younger (60.31 vs 70.93 years, p < 0.01), less likely to be Caucasian (66.37%vs 68.09%, p = 0.01), and had higher AIS severity (0.63 vs 0.58, p < 0.01). Tissue plasminogen activator (tPA) was administered in 99,739 (6.2%) fully-abled patients and 196 (4.79%) of patients with DD (p < 0.01). Endovascular thrombectomy (EVT) was performed in 21,066 (1.31%) of fully-abled patients and 35 (0.85%) of patients with DD (p < 0.01). The presence of developmental disabilities were predictive of lower rates of tPA (OR:0.71,CI:0.56-0.87,p < 0.01) and EVT (OR:0.24,CI:0.16-0.36,p < 0.01). In a propensity score-matched cohort of all AIS patients who underwent EVT, there was no difference in functional outcome (p = 0.41), in-hospital mortality (0.10), and LOS (p = 0.79). CONCLUSION: AIS patients with DD were less likely to receive tPA and EVT compared to fully-abled patients. Individuals with DD had higher mortality and worse discharge disposition. There was no significant difference in post-EVT outcomes between fully-abled patients and patients with developmental disabilities. In the absence of prospective clinical trials, population based cross-sectional analyses such as the present study provide valuable clinical insight.

Significant Mortality Associated With COVID-19 and Comorbid Cerebrovascular Disease: A Quantitative Systematic Review.

We report the first quantitative systematic review of cerebrovascular disease in coronavirus disease 2019 (COVID-19) to provide occurrence rates and associated mortality. Through a comprehensive search of PubMed we identified 8 cohort studies, 5 case series, and 2 case reports of acute cerebrovascular disease in patients with confirmed COVID-19 diagnosis. Our first meta-analysis utilizing the identified publications focused on comorbid cerebrovascular disease in recovered and deceased patients with COVID-19. We performed 3 additional meta-analyses of proportions to produce point estimates of the mortality and incidence of acute cerebrovascular disease in COVID-19 patients. Patient's with COVID-19 who died were 12.6 times more likely to have a history of cerebrovascular disease. We estimated an occurrence rate of 2.6% (95% confidence interval, 1.2-5.4%) for acute cerebrovascular disease among consecutively admitted patients with COVID-19. While for those with severe COVID-19' we estimated an occurrence rate of 6.5% (95% confidence interval, 4.4-9.6%). Our analysis estimated a rate of 35.5% for in-hospital mortality among COVID-19 patients with concomitant acute cerebrovascular disease. This was consistent with a mortality rate of 34.0% which we obtained through an individual patient analysis of 47 patients derived from all available case reports and case series. COVID-19 patients with either acute or chronic cerebrovascular disease have a high mortality rate with higher occurrence of cerebrovascular disease in patients with severe COVID-19.

Cervical fusion for adult patients with atlantoaxial rotatory subluxation.

Background: Atlantoaxial rotatory subluxation (AARS) is a rare injury of the C1/C2 junction. It is often associated with trauma in adults. Treatment may depend on the duration of symptoms and clinical presentation, but there is no consensus regarding the ideal management of these injuries. Our objective is to ascertain the prevalence of neurological deficit, complications, and outcomes of patients diagnosed with AARS undergoing cervical fusion (CF) versus those treated without CF. Methods: The 2016-2019 National Inpatient Sample (NIS) was queried using International Classification of Diseases, 10th revision (ICD-10) for adult patients with C1/C2 subluxation. Patients undergoing CF were defined through ICD-10 procedure codes. Baseline health and acute illness severity was calculated using the 11-point modified frailty index (mFI-11). Presenting characteristics, treatment complications, and outcomes were evaluated of CF vs. non-CF patients. Results: Of 990 adult patients with AARS, 720 were treated without CF and 270 were treated with CF. CF patients were more often myelopathic. Patients that had undergone CF treatment were negatively associated with having had extensive trauma. Patients undergoing CF experienced significantly longer length of stay (LOS), increased healthcare resource utilization, and decreased inpatient mortality. Sepsis had a negative association with patients that underwent CF treatment while pneumonia had a positive association. Conclusions: Adult patients undergoing CF for AARS demonstrated an increase in healthcare resource utilization but also a significant decrease in mortality. Extent of acute injury appears to have a strong influence on decision making for CF. Further study of decision making for treatment of this rare injury in adults is warranted.

Memantine Attenuates Cocaine and neuroHIV Neurotoxicity in the Medial Prefrontal Cortex.

Individuals with substance use disorder are at a higher risk of contracting HIV and progress more rapidly to AIDS as drugs of abuse, such as cocaine, potentiate the neurotoxic effects of HIV-associated proteins including, but not limited to, HIV-1 trans-activator of transcription (Tat) and the envelope protein Gp120. Neurotoxicity and neurodegeneration are hallmarks of HIV-1-associated neurocognitive disorders (HANDs), which are hypothesized to occur secondary to excitotoxicity from NMDA-induced neuronal calcium dysregulation, which could be targeted with NMDA antagonist drugs. Multiple studies have examined how Gp120 affects calcium influx and how cocaine potentiates this influx; however, they mostly focused on single cells and did not analyze effects in neuronal and vascular brain networks. Here, we utilize a custom multi-wavelength imaging platform to simultaneously study the neuronal activity (detected using genetically encoded Ca2+ indicator, GcaMP6f, expressed in neurons) and hemodynamic changes (measured by total hemoglobin and oxygenated hemoglobin within the tissue) in the prefrontal cortex (PFC) of HIV-1 Tg rats in response to cocaine and evaluate the effects of the selective NMDA antagonist drug memantine on cocaine and HIV neurotoxicity compared to those of non-HIV-1 Tg animals (controls). Our results show that memantine improved cocaine-induced deficit in cerebral blood volume while also attenuating an abnormal increase of the neuronal calcium influx and influx duration in both control rats and HIV-1 Tg rats. Cocaine-induced neuronal and hemodynamic dysregulations were significantly greater in HIV-1 Tg rats than in control rats. With memantine pretreatment, HIV-1 Tg rats showed attenuated cocaine's effects on neuronal and hemodynamic responses, with responses similar to those observed in control rats. These imaging results document an enhancement of neuronal Ca2+ influx, hypoxemia, and ischemia with cocaine in the PFC of HIV-1 Tg rats that were attenuated by memantine pretreatment. Thus, the potential utility of memantine in the treatment of HAND and of cocaine-induced neurotoxicity deserves further investigation.

Cocaine's effects on the reactivity of the medial prefrontal cortex to ventral tegmental area stimulation: optical imaging study in mice.

BACKGROUND AND AIMS: The prefrontal cortex (PFC) is modulated by dopaminergic and glutamatergic neurons that project from the ventral tegmental area (VTA) and disruption of this modulation might facilitate impulsive behaviors during cocaine intoxication. Here, we assessed the effects of acute cocaine (30 mg/kg, i.p.) on the reactivity of the PFC to VTA stimulation. METHODS: Using a genetically encoded calcium indicator (GCaMP6f), we optically imaged the neuronal Ca2+ reactance in medial PFC (mPFC) in response to 'tonic-like' (5 Hz) and 'phasic-like' (50 Hz) electrical VTA stimulation. The high temporal and spatial resolutions of our optical system allowed us to capture single Ca2+ neuronal transients from individual stimuli with 'tonic-like' stimulation and to visualize single neuronal activation evoked by 'phasic-like' VTA stimulation. RESULTS: 'Tonic-like' VTA stimulation induced a rapid increase in mean neuronal Ca2+ in mPFC followed by a plateau and recovery upon termination of stimulation. After cocaine, the mPFC sensitivity to 'tonic-like' VTA stimulation was attenuated, with a 50.4% reduction (P = 0.03) in the number of Ca2+ transients corresponding to single electrical stimuli but the recovery time was lengthened (4.30 ± 0.25 sec to 5.41 ± 0.24 sec, P = 0.03). 'Phasic-like' stimulation evoked a rapid Ca2+ fluorescence increase in mPFC with an immediate decay process, and while cocaine did not affect the peak response (7.17 ± 1.07% versus 7.13 ± 0.96%, P = 0.98) it shortened the recovery time to baseline (3.27 ± 0.11 sec versus 2.38 ± 0.23 sec, P = 0.005). CONCLUSIONS: Acute cocaine impairs reactivity of medial prefrontal cortex (mPFC) to ventral tegmental area stimulation, decreasing its sensitivity to 'tonic-like' stimulation and lengthening the recovery time to return to baseline while shortening it for phasic stimulation. These changes in mPFC might contribute to cocaine binging during intoxication.

Safety and efficacy of a novel robotic transcranial doppler system in subarachnoid hemorrhage.

Delayed cerebral ischemia (DCI) secondary to vasospasm is a determinate of outcomes following non-traumatic subarachnoid hemorrhage (SAH). SAH patients are monitored using transcranial doppler (TCD) to measure cerebral blood flow velocities (CBFv). However, the accuracy and precision of manually acquired TCD can be operator dependent. The NovaGuide robotic TCD system attempts to standardize acquisition. This investigation evaluated the safety and efficacy of the NovaGuide system in SAH patients in a Neuro ICU. We retrospectively identified 48 NovaGuide scans conducted on SAH patients. Mean and maximum middle cerebral artery (MCA) CBFv were obtained from the NovaGuide and the level of agreement between CBFv and computed tomography angiography (CTA) for vasospasm was determined. Safety of NovaGuide acquisition of CBFv was evaluated based on number of complications with central venous lines (CVL) and external ventricular drains (EVD). There was significant agreement between the NovaGuide and CTA (Cohen's Kappa = 0.74) when maximum MCA CBFv ≥ 120 cm/s was the threshold for vasospasm. 27/48 scans were carried out with CVLs and EVDs present without negative outcomes. The lack of adverse events associated with EVDs/CVLs and the strong congruence between maximal MCA CBFv and CTA illustrates the diagnostic utility of the NovaGuide.

Cocaine Reduces the Neuronal Population While Upregulating Dopamine D2-Receptor-Expressing Neurons in Brain Reward Regions: Sex-Effects.

Addiction to cocaine is associated with dysfunction of the dopamine mesocortical system including impaired dopamine-2 receptor (D2r) signaling. However, the effects of chronic cocaine on neuronal adaptations in this system have not been systematically examined and data available is mostly from males. Here, we investigated changes in the total neuronal density and relative concentration of D2r-expressing neurons in the medial prefrontal cortex (mPFC), dorsal striatum (Dstr), nucleus accumbens (NAc), and ventral tegmental area (VTA) in both male and female mice passively exposed to cocaine for two weeks. In parallel experiments, we measured mRNA levels for Drd2 and for opioid peptides (mPenk and mPdyn). Through a combination of large field of view fluorescent imaging with BAC transgenic D2r-eGFP mice and immunostaining, we observed that cocaine exposed mice had a higher density of D2r-positive cells that was most prominent in mPFC and VTA and larger for females than for males. This occurred amidst an overall significant decrease in neuronal density (measured with NeuN) in both sexes. However, increases in Drd2 mRNA levels with cocaine were only observed in mPFC and Dstr in females, which might reflect the limited sensitivity of the method. Our findings, which contrast with previous findings of cocaine-induced downregulation of D2r binding availability, could reflect a phenotypic shift in neurons that did not previously express Drd2 and merits further investigation. Additionally, the neuronal loss particularly in mPFC with chronic cocaine might contribute to the cognitive impairments observed with cocaine use disorder.

Systematic elucidation of neuron-astrocyte interaction in models of amyotrophic lateral sclerosis using multi-modal integrated bioinformatics workflow.

Cell-to-cell communications are critical determinants of pathophysiological phenotypes, but methodologies for their systematic elucidation are lacking. Herein, we propose an approach for the Systematic Elucidation and Assessment of Regulatory Cell-to-cell Interaction Networks (SEARCHIN) to identify ligand-mediated interactions between distinct cellular compartments. To test this approach, we selected a model of amyotrophic lateral sclerosis (ALS), in which astrocytes expressing mutant superoxide dismutase-1 (mutSOD1) kill wild-type motor neurons (MNs) by an unknown mechanism. Our integrative analysis that combines proteomics and regulatory network analysis infers the interaction between astrocyte-released amyloid precursor protein (APP) and death receptor-6 (DR6) on MNs as the top predicted ligand-receptor pair. The inferred deleterious role of APP and DR6 is confirmed in vitro in models of ALS. Moreover, the DR6 knockdown in MNs of transgenic mutSOD1 mice attenuates the ALS-like phenotype. Our results support the usefulness of integrative, systems biology approach to gain insights into complex neurobiological disease processes as in ALS and posit that the proposed methodology is not restricted to this biological context and could be used in a variety of other non-cell-autonomous communication mechanisms.

Chronic cocaine induces HIF-VEGF pathway activation along with angiogenesis in the brain.

Cocaine induces vasoconstriction in cerebral vessels, which with repeated use can result in transient ischemic attacks and cerebral strokes. However, the neuroadaptations that follow cocaine's vasoconstricting effects are not well understood. Here, we investigated the effects of chronic cocaine exposure (2 and 4 weeks) on markers of vascular function and morphology in the rat brain. For this purpose we measured nitric oxide (NO) concentration in plasma, brain neuronal nitric oxide synthase (nNOS or NOS1), HIF-1α, and VEGF expression in different brain regions, i.e., middle prefrontal cortex, somatosensory cortex, nucleus accumbens, and dorsal striatum, using ELISA or Western blot. Additionally, microvascular density in these brain regions was measured using immunofluorescence microscopy. We showed that chronic cocaine significantly affected NOS1, HIF-1α and VEGF expression, in a region- and cocaine treatment-time- dependent manner. Cerebral microvascular density increased significantly in parallel to these neurochemical changes. Furthermore, significant correlations were detected between VEGF expression and microvascular density in cortical regions (middle prefrontal cortex and somatosensory cortex), but not in striatal regions (nucleus accumbens and dorsal striatum). These results suggest that following chronic cocaine use, as cerebral ischemia developed, NOS1, the regulatory protein to counteract blood vessel constriction, was upregulated; meanwhile, the HIF-VEGF pathway was activated to increase microvascular density (i.e., angiogenesis) and thus restore local blood flow and oxygen supply. These physiological responses were triggered presumably as an adaptation to minimize ischemic injury caused by cocaine. Therefore, effectively promoting such physiological responses may provide novel and effective therapeutic solutions to treat cocaine-induced cerebral ischemia and stroke.