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1.
J Child Neurol ; 39(1-2): 55-60, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38351705

RESUMO

Background: Chronic migraine in children has been a challenging condition to treat, prompting the investigation of alternative therapies. This retrospective single-center chart review aimed to evaluate the efficacy and safety of Botox injections for managing chronic migraine in children. Methods: The study included children with chronic daily headaches and chronic migraine who were medically refractory to previous treatments at OSF Healthcare/Illinois Neurological Institute, Peoria, between 2015 and 2021. Botox injections were administered quarterly following a specific protocol. Data were obtained from electronic medical records by manual review. Results: Twenty-four patients met the inclusion criteria (median age 15.4 years, 87% female). Comorbidities included depression (41.6%) and sleep disturbances (33.2%). Prior to Botox treatment, patients had been tried on a median number of 5 (interquartile range [IQR] 4, 7) medications. Botox injections resulted in a significant reduction in headache frequency, with a mean difference (6 months vs pretreatment) in the Headache Impact Test (HIT 3) scores of -19.6 (95% CI -24.8, -14.3), P < .001, and mean difference in the Migraine Disability Assessment (MIDAS) scores of -50.8 (95% CI -62.6, -39.0, P < .001). Subjective improvements included mood enhancement (13/24, 54.2%) and improved concentration (12/24, 50%). Treatment-related side effects were reported by 5/24 (20%) of patients and were mostly mild to moderate. Conclusions: Botox injections offer a promising therapeutic option for managing chronic migraine in children who have not responded to traditional medications. Future controlled trials and long-term follow-up studies are needed to further evaluate Botox treatment's benefits and adverse effects in children with chronic migraine.


Assuntos
Toxinas Botulínicas Tipo A , Transtornos da Cefaleia , Qualidade de Vida , Humanos , Toxinas Botulínicas Tipo A/uso terapêutico , Toxinas Botulínicas Tipo A/administração & dosagem , Toxinas Botulínicas Tipo A/efeitos adversos , Feminino , Masculino , Adolescente , Estudos Retrospectivos , Transtornos da Cefaleia/tratamento farmacológico , Criança , Resultado do Tratamento , Fármacos Neuromusculares/uso terapêutico , Fármacos Neuromusculares/administração & dosagem , Fármacos Neuromusculares/efeitos adversos , Transtornos de Enxaqueca/tratamento farmacológico
2.
Crit Care Explor ; 5(10): e0981, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37753239

RESUMO

OBJECTIVES: A number of trials related to critical care pharmacotherapy were published in 2022. We aimed to summarize the most influential publications related to the pharmacotherapeutic care of critically ill patients in 2022. DATA SOURCES: PubMed/Medical Literature Analysis and Retrieval System Online and the Clinical Pharmacy and Pharmacology Pharmacotherapy Literature Update. STUDY SELECTION: Randomized controlled trials, prospective studies, or systematic review/meta-analyses of adult critically ill patients assessing a pharmacotherapeutic intervention and reporting clinical endpoints published between January 1, 2022, and December 31, 2022, were included in this article. DATA EXTRACTION: Articles from a systematic search and the Clinical Pharmacy and Pharmacology Pharmacotherapy Literature Update were included and stratified into clinical domains based upon consistent themes. Consensus was obtained on the most influential publication within each clinical domain utilizing an a priori defined three-round modified Delphi process with the following considerations: 1) overall contribution to scientific knowledge and 2) novelty to the literature. DATA SYNTHESIS: The systematic search and Clinical Pharmacy and Pharmacology Pharmacotherapy Literature Update yielded a total of 704 articles, of which 660 were excluded. The remaining 44 articles were stratified into the following clinical domains: emergency/neurology, cardiovascular, gastroenterology/fluids/nutrition, hematology, infectious diseases/immunomodulation, and endocrine/metabolic. The final article selected from each clinical domain was summarized following a three-round modified Delphi process and included three randomized controlled trials and three systematic review/meta-analyses. Article topics summarized included dexmedetomidine versus other sedatives during mechanical ventilation, beta-blocker treatment in the critically ill, restriction of IV fluids in septic shock, venous thromboembolism prophylaxis in critically ill adults, duration of antibiotic therapy for Pseudomonas aeruginosa ventilator-associated pneumonia, and low-dose methylprednisolone treatment in severe community-acquired pneumonia. CONCLUSIONS: This concise review provides a perspective on articles published in 2022 that are relevant to the pharmacotherapeutic care of critically ill patients and their potential impact on clinical practice.

3.
Crit Care Explor ; 5(7): e0943, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37396931

RESUMO

Self-fulfilling prophecy bias occurs when a perceived prognosis leads to treatment decisions that inherently modify outcomes of a patient, and thus, overinflate the prediction performance of prognostic methods. The goal of this series of systematic reviews is to characterize the extent to which neuroprognostic studies account for the potential impact of self-fulfilling prophecy bias in their methodology by assessing their adequacy of disclosing factors relevant to this bias. Methods: Studies evaluating the prediction performance of neuroprognostic tools in cardiac arrest, malignant ischemic stroke, traumatic brain injury, subarachnoid hemorrhage, and spontaneous intracerebral hemorrhage will be identified through PubMed, Cochrane, and Embase database searches. Two reviewers blinded to each other's assessment will perform screening and data extraction of included studies using Distiller SR and following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We will abstract data pertinent to the methodology of the studies relevant to self-fulfilling prophecy bias. Results: We will conduct a descriptive analysis of the data. We will summarize the reporting of mortality according to timing and mode of death, rates of exposure to withdrawal of life-sustaining therapy, reasoning behind limitations of supportive care, systematic use of standardized neuroprognostication algorithms and whether the tool being investigated is part of such assessments, and blinding of treatment team to results of neuroprognostic test being evaluated. CONCLUSIONS: We will identify if neuroprognostic studies have been transparent in their methodology to factors that affect the self-fulfilling prophecy bias. Our results will serve as the foundation for standardization of neuroprognostic study methodologies by refining the quality of the data derived from such studies.

4.
Stroke ; 54(1): 189-197, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36314124

RESUMO

BACKGROUND: Targeting a cerebral perfusion pressure optimal for cerebral autoregulation (CPPopt) has been gaining more attention to prevent secondary damage after acute neurological injury. Brain tissue oxygenation (PbtO2) can identify insufficient cerebral blood flow and secondary brain injury. Defining the relationship between CPPopt and PbtO2 after aneurysmal subarachnoid hemorrhage may result in (1) mechanistic insights into whether and how CPPopt-based strategies might be beneficial and (2) establishing support for the use of PbtO2 as an adjunctive monitor for adequate or optimal local perfusion. METHODS: We performed a retrospective analysis of a prospectively collected 2-center dataset of patients with aneurysmal subarachnoid hemorrhage with or without later diagnosis of delayed cerebral ischemia (DCI). CPPopt was calculated as the cerebral perfusion pressure (CPP) value corresponding to the lowest pressure reactivity index (moving correlation coefficient of mean arterial and intracranial pressure). The relationship of (hourly) deltaCPP (CPP-CPPopt) and PbtO2 was investigated using natural spline regression analysis. Data after DCI diagnosis were excluded. Brain tissue hypoxia was defined as PbtO2 <20 mmHg. RESULTS: One hundred thirty-one patients were included with a median of 44.0 (interquartile range, 20.8-78.3) hourly CPPopt/PbtO2 datapoints. The regression plot revealed a nonlinear relationship between PbtO2 and deltaCPP (P<0.001) with PbtO2 decrease with deltaCPP <0 mmHg and stable PbtO2 with deltaCPP ≥0mmHg, although there was substantial individual variation. Brain tissue hypoxia (34.6% of all measurements) was more frequent with deltaCPP <0 mmHg. These dynamics were similar in patients with or without DCI. CONCLUSIONS: We found a nonlinear relationship between PbtO2 and deviation of patients' CPP from CPPopt in aneurysmal subarachnoid hemorrhage patients in the pre-DCI period. CPP values below calculated CPPopt were associated with lower PbtO2. Nevertheless, the nature of PbtO2 measurements is complex, and the variability is high. Combined multimodality monitoring with CPP/CPPopt and PbtO2 should be recommended to redefine individual pressure targets (CPP/CPPopt) and retain the option to detect local perfusion deficits during DCI (PbtO2), which cannot be fulfilled by both measurements interchangeably.


Assuntos
Lesões Encefálicas Traumáticas , Isquemia Encefálica , Hemorragia Subaracnóidea , Humanos , Estudos Retrospectivos , Oxigênio , Encéfalo/diagnóstico por imagem , Infarto Cerebral , Pressão Intracraniana , Circulação Cerebrovascular/fisiologia , Hipóxia , Lesões Encefálicas Traumáticas/diagnóstico
5.
Hosp Pediatr ; 12(11): 945-953, 2022 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-36193689

RESUMO

OBJECTIVES: Evaluate the implementation of a pharmacist-managed opioid weaning regimen and objective opioid withdrawal assessment tool in pediatric patients requiring an opioid wean. We hypothesized that this combination would be associated with a reduction in the wean duration and length of stay and decrease episodes of opioid withdrawal. METHODS: Retrospective cohort study utilizing pediatric inpatients requiring an inpatient opioid medication wean. The study was conducted in 3 phases from chart review of patients admitted from 2012 to 2020: baseline preintervention (phase 1), pharmacist-managed weaning regimen (phase 2), and addition of an objective assessment tool, the Withdrawal Assessment Tool-1 (phase 3). Data collection included the total wean duration, total duration of hospital admission, and number of episodes of opioid withdrawal. RESULTS: The study included 115 patients with 36 patients in phases 1 and 3 and 43 patients in phase 2. Median age ranged from 0.46 to 0.84 years and the majority of children were males. No significant differences in patient characteristics such as age, weight, sex, and previous opioid exposure were found between phases. Length of stay, wean duration, and episodes of withdrawal with need for rescue dose all decreased significantly from phase 1 to phase 3. CONCLUSIONS: Use of a pharmacist-managed weaning regimen combined with the Withdrawal Assessment Tool-1 tool was associated with significantly shorter methadone weans and overall length of stay. This has implications for wide spread dissemination and standardization of this approach in tertiary care children's hospitals caring for patients after ICU admission.


Assuntos
Analgésicos Opioides , Síndrome de Abstinência a Substâncias , Masculino , Criança , Humanos , Lactente , Feminino , Analgésicos Opioides/uso terapêutico , Estudos Retrospectivos , Atenção Terciária à Saúde , Metadona/uso terapêutico , Síndrome de Abstinência a Substâncias/tratamento farmacológico , Hospitais
6.
Neurocrit Care ; 37(3): 670-677, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-35750930

RESUMO

BACKGROUND: Prolonged external ventricular drainage (EVD) in patients with subarachnoid hemorrhage (SAH) leads to morbidity, whereas early removal can have untoward effects related to recurrent hydrocephalus. A metric to help determine the optimal time for EVD removal or ventriculoperitoneal shunt (VPS) placement would be beneficial in preventing the prolonged, unnecessary use of EVD. This study aimed to identify whether dynamics of cerebrospinal fluid (CSF) biometrics can temporally predict VPS dependency after SAH. METHODS: This was a retrospective analysis of a prospective, single-center, observational study of patients with aneurysmal SAH who required EVD placement for hydrocephalus. Patients were divided into VPS-dependent (VPS+) and non-VPS dependent groups. We measured the bicaudate index (BCI) on all available computed tomography scans and calculated the change over time (ΔBCI). We analyzed the relationship of ΔBCI with CSF output by using Pearson's correlation. A k-nearest neighbor model of the relationship between ΔBCI and CSF output was computed to classify VPS. RESULTS: Fifty-eight patients met inclusion criteria. CSF output was significantly higher in the VPS+ group in the 7 days post EVD placement. There was a negative correlation between delta BCI and CSF output in the VPS+ group (negative delta BCI means ventricles become smaller) and a positive correlation in the VPS- group starting from days four to six after EVD placement (p < 0.05). A weighted k-nearest neighbor model for classification had a sensitivity of 0.75, a specificity of 0.70, and an area under the receiver operating characteristic curve of 0.80. CONCLUSIONS: The correlation of ΔBCI and CSF output is a reliable intraindividual biometric for VPS dependency after SAH as early as days four to six after EVD placement. Our machine learning model leverages this relationship between ΔBCI and cumulative CSF output to predict VPS dependency. Early knowledge of VPS dependency could be studied to reduce EVD duration in many centers (intensive care unit length of stay).


Assuntos
Hidrocefalia , Hemorragia Subaracnóidea , Humanos , Estudos Retrospectivos , Estudos Prospectivos , Derivação Ventriculoperitoneal , Hidrocefalia/cirurgia , Vazamento de Líquido Cefalorraquidiano , Hemorragia Subaracnóidea/cirurgia , Drenagem/métodos , Derivações do Líquido Cefalorraquidiano
7.
Neurocrit Care ; 37(Suppl 2): 230-236, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35352273

RESUMO

BACKGROUND: Dysfunctional cerebral autoregulation often precedes delayed cerebral ischemia (DCI). Currently, there are no data-driven techniques that leverage this information to predict DCI in real time. Our hypothesis is that information using continuous updated analyses of multimodal neuromonitoring and cerebral autoregulation can be deployed to predict DCI. METHODS: Time series values of intracranial pressure, brain tissue oxygenation, cerebral perfusion pressure (CPP), optimal CPP (CPPOpt), ΔCPP (CPP - CPPOpt), mean arterial pressure, and pressure reactivity index were combined and summarized as vectors. A validated temporal signal angle measurement was modified into a classification algorithm that incorporates hourly data. The time-varying temporal signal angle measurement (TTSAM) algorithm classifies DCI at varying time points by vectorizing and computing the angle between the test and reference time signals. The patient is classified as DCI+ if the error between the time-varying test vector and DCI+ reference vector is smaller than that between the time-varying test vector and DCI- reference vector. Finally, prediction at time point t is calculated as the majority voting over all the available signals. The leave-one-patient-out cross-validation technique was used to train and report the performance of the algorithms. The TTSAM and classifier performance was determined by balanced accuracy, F1 score, true positive, true negative, false positive, and false negative over time. RESULTS: One hundred thirty-one patients with aneurysmal subarachnoid hemorrhage who underwent multimodal neuromonitoring were identified from two centers (Columbia University: 52 [39.7%], Aachen University: 79 [60.3%]) and included in the analysis. Sixty-four (48.5%) patients had DCI, and DCI was diagnosed 7.2 ± 3.3 days after hemorrhage. The TTSAM algorithm achieved a balanced accuracy of 67.3% and an F1 score of 0.68 at 165 h (6.9 days) from bleed day with a true positive of 0.83, false positive of 0.16, true negative of 0.51, and false negative of 0.49. CONCLUSIONS: A TTSAM algorithm using multimodal neuromonitoring and cerebral autoregulation calculations shows promise to classify DCI in real time.


Assuntos
Isquemia Encefálica , Hemorragia Subaracnóidea , Isquemia Encefálica/diagnóstico , Infarto Cerebral , Circulação Cerebrovascular/fisiologia , Humanos , Pressão Intracraniana
8.
Neurohospitalist ; 11(4): 342-347, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34567395

RESUMO

BACKGROUND AND PURPOSE: With the surge of critically ill COVID-19 patients, neurology and neurosurgery residents and advanced practice providers (APPs) were deployed to intensive care units (ICU). These providers lacked relevant critical care training. We investigated whether a focused video-based learning curriculum could effectively teach high priority intensive care topics in this unprecedented setting to these neurology providers. METHODS: Neurocritical care clinicians led a multidisciplinary team in developing a 2.5-hour lecture series covering the critical care management of COVID-19 patients. We examined whether provider confidence, stress, and knowledge base improved after viewing the lectures. RESULTS: A total of 88 residents and APPs participated across 2 academic institutions. 64 participants (73%) had not spent time as an ICU provider. After viewing the lecture series, the proportion of providers who felt moderately, quite, or extremely confident increased from 11% to 72% (60% difference, 95% CI 49-72%) and the proportion of providers who felt nervous/stressed, very nervous/stressed, or extremely nervous/stressed decreased from 78% to 48% (38% difference, 95% CI 26-49%). Scores on knowledge base questions increased an average of 2.5 out of 12 points (SD 2.1; p < 0.001). CONCLUSION: A targeted, asynchronous curriculum on critical care COVID-19 management led to significantly increased confidence, decreased stress, and improved knowledge among resident trainees and APPs. This curriculum could serve as an effective didactic resource for neurology providers preparing for the COVID-19 ICU.

9.
J Cereb Blood Flow Metab ; 40(6): 1290-1299, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-31296131

RESUMO

The association between impaired brain perfusion, cerebrovascular reactivity status and the risk of ictal events in patients with subarachnoid hemorrhage is unknown. We identified 13 subarachnoid hemorrhage (SAH) patients with seizures and 22 with ictal-interictal continuum (IIC), and compared multimodality physiological recordings to 38 similarly poor-grade SAH patients without ictal activity. We analyzed 10,179 cumulative minutes of seizure and 12,762 cumulative minutes of IIC. Cerebrovascular reactivity (PRx) was not different between subjects with seizures, IIC, or controls. Cerebral perfusion pressure (CPP) was higher in patients with seizures [99 ± 6.5, p = .005] and IIC [97 ± 8.5, p = .007] when compared to controls [89 ± 12.3]. DeltaCPP, defined as actual CPP minus optimal CPP (CPPopt), was also higher in the seizure group [8.3 ± 7.9, p = .0003] and IIC [8.1 ± 10.3, p = .0006] when compared to controls [-0.1 ± 5]. Time spent with supra-optimal CPP was higher in the seizure group [342 ± 213 min/day, p = .002] when compared to controls [154 ± 120 min/day]. In a temporal examination, a supra-optimal CPP preceded increased seizures and IIC in SAH patients, an hour before and continued to increase during the events [p < .0001].


Assuntos
Encéfalo/irrigação sanguínea , Hiperemia/fisiopatologia , Convulsões/etiologia , Hemorragia Subaracnóidea/fisiopatologia , Idoso , Encéfalo/fisiopatologia , Circulação Cerebrovascular/fisiologia , Feminino , Homeostase/fisiologia , Humanos , Hiperemia/etiologia , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Hemorragia Subaracnóidea/complicações
10.
Physiol Meas ; 40(1): 015002, 2019 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-30562165

RESUMO

OBJECTIVE: Intracranial pressure (ICP) is an important and established clinical measurement that is used in the management of severe acute brain injury. ICP waveforms are usually triphasic and are susceptible to artifact because of transient catheter malfunction or routine patient care. Existing methods for artifact detection include threshold-based, stability-based, or template matching, and result in higher false positives (when there is variability in the ICP waveforms) or higher false negatives (when the ICP waveforms lack complete triphasic components but are valid). APPROACH: We hypothesized that artifact labeling of ICP waveforms can be optimized by an active learning approach which includes interactive querying of domain experts to identify a manageable number of informative training examples. MAIN RESULTS: The resulting active learning based framework identified non-artifactual ICP pulses with a superior AUC of 0.96 + 0.012, compared to existing methods: template matching (AUC: 0.71 + 0.04), ICP stability (AUC: 0.51 + 0.036) and threshold-based (AUC: 0.5 + 0.02). SIGNIFICANCE: The proposed active learning framework will support real-time ICP-derived analytics by improving precision of artifact-labelling.


Assuntos
Pressão Intracraniana , Aprendizado de Máquina , Processamento de Sinais Assistido por Computador , Artefatos , Lesões Encefálicas/diagnóstico , Lesões Encefálicas/fisiopatologia , Reações Falso-Positivas , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
11.
Neurosurg Focus ; 32(2): E1, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22296678

RESUMO

The overall incidence of neurological complications due to infective endocarditis is as high as 40%, with embolic infarcts more common than hemorrhagic strokes. The standard of care for typical strokes does not apply to infective endocarditis because there is a substantial risk of hemorrhage with thrombolysis. In the last decade there have been multiple case reports of intravenous and intraarterial thrombolysis with successful outcomes for acute strokes with related infective endocarditis, but successful endovascular interventions for acute strokes associated with infective endocarditis are rarely reported. To the authors' knowledge, this report is the first case in the literature to use a mechanical retrieval device in successful vegetation retrieval in an infective endocarditis acute stroke. Although an interventional approach for treatment of acute stroke related to infective endocarditis is a promising option, it is controversial and a cautious clinical decision should be made on a case-by-case basis. The authors conclude that this approach can be tested in a case series with matched controls, because this condition is rare and a randomized clinical trial is not a realistic option.


Assuntos
Endocardite/complicações , Endocardite/cirurgia , Procedimentos Endovasculares/métodos , Acidente Vascular Cerebral/etiologia , Acidente Vascular Cerebral/cirurgia , Idoso , Endocardite/diagnóstico , Feminino , Humanos , Acidente Vascular Cerebral/diagnóstico
12.
Pharmacol Biochem Behav ; 101(1): 62-8, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22182462

RESUMO

The majority of smokers relapse during the acute withdrawal phase when withdrawal symptoms are most severe. The goal of the present studies was to investigate the role of corticotropin-releasing factor (CRF) and noradrenergic transmission in the central nucleus of the amygdala (CeA) in the dysphoria associated with smoking cessation. It was investigated if blockade of CRF1 receptors, blockade of α1-adrenergic receptors, or stimulation of α2-adrenergic receptors in the CeA diminishes the deficit in brain reward function associated with nicotine withdrawal in rats. Nicotine dependence was induced by implanting minipumps that delivered a nicotine solution. Withdrawal was precipitated with the nicotinic acetylcholine receptor antagonist mecamylamine. A discrete-trial intracranial self-stimulation procedure was used to assess the negative affective aspects of nicotine withdrawal. Elevations in brain reward thresholds are indicative of a deficit in brain reward function. In all the experiments, mecamylamine elevated the brain reward thresholds of the rats chronically treated with nicotine and did not affect the brain reward thresholds of the saline-treated control rats. Intra-CeA administration of the CRF1 receptor antagonist R278995/CRA0450 completely prevented the mecamylamine-induced elevations in brain reward thresholds in the nicotine-treated rats and did not affect the brain reward thresholds of the saline-treated control rats. R278995/CRA0450 has also been shown to block sigma-1 receptors but there is no evidence that this could affect negative mood states. Intra-CeA administration of the α1-adrenergic receptor antagonist prazosin or the α2-adrenergic receptor agonist clonidine did not affect the brain reward thresholds of the nicotine or saline-treated rats. These studies suggest that CRF1 receptor antagonists may diminish the dysphoria associated with smoking cessation by blocking CRF1 receptors in the CeA.


Assuntos
Tonsila do Cerebelo/efeitos dos fármacos , Nicotina/farmacologia , Agonistas Nicotínicos/farmacologia , Receptores de Hormônio Liberador da Corticotropina/antagonistas & inibidores , Abandono do Hábito de Fumar/psicologia , Síndrome de Abstinência a Substâncias/psicologia , Tabagismo/psicologia , Antagonistas de Receptores Adrenérgicos alfa 1/farmacologia , Antagonistas de Receptores Adrenérgicos alfa 2/farmacologia , Animais , Benzenossulfonatos/farmacologia , Clonidina/farmacologia , Eletrodos Implantados , Masculino , Mecamilamina/farmacologia , Antagonistas Nicotínicos/farmacologia , Prazosina/farmacologia , Quinolinas/farmacologia , Ratos , Ratos Wistar , Recompensa , Síndrome de Abstinência a Substâncias/tratamento farmacológico
13.
Psychopharmacology (Berl) ; 212(4): 485-99, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20697697

RESUMO

RATIONALE: Tobacco withdrawal is characterized by a negative mood state and relatively mild somatic symptoms. Increased noradrenergic transmission has been reported to play an important role in opioid withdrawal, but little is known about the role of noradrenergic transmission in nicotine withdrawal. OBJECTIVES: The aim of these experiments was to investigate the effects of prazosin, clonidine, and propranolol on the negative mood state and somatic signs associated with nicotine withdrawal in rats. METHODS: A discrete-trial intracranial self-stimulation procedure was used to assess the negative affective state of nicotine withdrawal. Elevations in brain reward thresholds are indicative of a deficit in brain reward function. RESULTS: In all the experiments, the nicotinic acetylcholine receptor antagonist mecamylamine (3 mg/kg) elevated the brain reward thresholds of the nicotine-treated rats and did not affect those of the control rats. The α1-adrenergic receptor antagonist prazosin (0.0625 and 0.125 mg/kg) dose-dependently attenuated the elevations in brain reward thresholds associated with precipitated nicotine withdrawal. The α2-adrenergic receptor agonist clonidine (10-40 µg/kg) and the nonselective ß-adrenergic receptor antagonist propranolol (2.5-10 mg/kg) did not attenuate the elevations in brain reward thresholds associated with nicotine withdrawal. Furthermore, mecamylamine (2 mg/kg) induced more somatic signs in the nicotine-treated rats than in the control rats. Clonidine and propranolol, but not prazosin, decreased the total number of somatic signs associated with nicotine withdrawal. CONCLUSION: Blockade of α1-adrenergic receptors attenuates the deficit in brain reward function associated with nicotine withdrawal. Antagonism of ß-adrenergic receptors or stimulation of α2-adrenergic receptors attenuates the somatic symptoms of nicotine withdrawal.


Assuntos
Antagonistas de Receptores Adrenérgicos alfa 1/farmacologia , Agonistas de Receptores Adrenérgicos alfa 2/farmacologia , Antagonistas Adrenérgicos beta/farmacologia , Comportamento Animal/efeitos dos fármacos , Clonidina/farmacologia , Nicotina/efeitos adversos , Agonistas Nicotínicos/efeitos adversos , Prazosina/farmacologia , Propranolol/farmacologia , Recompensa , Síndrome de Abstinência a Substâncias/tratamento farmacológico , Tabagismo/tratamento farmacológico , Animais , Relação Dose-Resposta a Droga , Masculino , Antagonistas Nicotínicos/farmacologia , Ratos , Ratos Wistar , Tempo de Reação/efeitos dos fármacos , Reforço Psicológico , Síndrome de Abstinência a Substâncias/etiologia , Síndrome de Abstinência a Substâncias/psicologia , Tabagismo/psicologia
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