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1.
Jt Comm J Qual Patient Saf ; 49(9): 450-457, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37193611

RESUMO

PURPOSE: Evidence suggests in-person multidisciplinary rounds can help reduce length of stay (LOS) and improve throughput, but there are limited studies about the effectiveness of virtual multidisciplinary rounds on these measures. The authors hypothesized that virtual multidisciplinary rounds could help reduce LOS, improve throughput, promote accountability, and reduce provider variation. METHODS: The research team designed and implemented virtual multidisciplinary rounds by a phone conference call with key stakeholders, including hospitalists, case managers, the clinical documentation improvement team, physical and occupational therapy, and nursing leaders. To track progress in real time, dashboards were created using data from electronic medical records. After several months, unit-based discharge huddles were also implemented to supplement the process and sustain the improvement. RESULTS: The interventions led to more than 60% of discharges below geometric mean LOS after starting the initiative, compared to approximately 52% before the initiative. Mean observation hours went from around 44 hours to 31.9 hours, and the change was sustained for more than a year. In fiscal year 2021, 3,813 excess days were reduced in 10 months, resulting in combined savings of $6.7 million. A decrease in hospitalist provider variation is noted with the initiative, which is a crucial contributor to the results. CONCLUSION: Virtual multidisciplinary rounds combined with other interventions can effectively reduce LOS and observation hours. Decreasing variation among hospitalists and improved key stakeholder engagement can be achieved with virtual multidisciplinary rounds. More studies to test the effectiveness of virtual multidisciplinary rounds in various patient care settings would provide more insights.


Assuntos
Equipe de Assistência ao Paciente , Alta do Paciente , Humanos , Tempo de Internação , Estudos Interdisciplinares , Responsabilidade Social
2.
Sci Rep ; 12(1): 6493, 2022 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-35444245

RESUMO

In parkinsonism, subthalamic nucleus (STN) electrical deep brain stimulation (DBS) improves symptoms, but may be associated with side effects. Adaptive DBS (aDBS), which enables modulation of stimulation, may limit side effects, but limited information is available about clinical effectiveness and efficaciousness. We developed a brain-machine interface for aDBS, which enables modulation of stimulation parameters of STN-DBS in response to γ2 band activity (80-200 Hz) of local field potentials (LFPs) recorded from the primary motor cortex (M1), and tested its effectiveness in parkinsonian monkeys. We trained two monkeys to perform an upper limb reaching task and rendered them parkinsonian with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine. Bipolar intracortical recording electrodes were implanted in the M1, and a recording chamber was attached to access the STN. In aDBS, the M1 LFPs were recorded, filtered into the γ2 band, and discretized into logic pulses by a window discriminator, and the pulses were used to modulate the interval and amplitude of DBS pulses. In constant DBS (cDBS), constant stimulus intervals and amplitudes were used. Reaction and movement times during the task were measured and compared between aDBS and cDBS. The M1-γ2 activities were increased before and during movements in parkinsonian monkeys and these activities modulated the aDBS pulse interval, amplitude, and dispersion. With aDBS and cDBS, reaction and movement times were significantly decreased in comparison to DBS-OFF. The electric charge delivered was lower with aDBS than cDBS. M1-γ2 aDBS in parkinsonian monkeys resulted in clinical benefits that did not exceed those from cDBS. However, M1-γ2 aDBS achieved this magnitude of benefit for only two thirds of the charge delivered by cDBS. In conclusion, M1-γ2 aDBS is an effective therapeutic approach which requires a lower electrical charge delivery than cDBS for comparable clinical benefits.


Assuntos
Estimulação Encefálica Profunda , Córtex Motor , Transtornos Parkinsonianos , Núcleo Subtalâmico , Animais , Estimulação Encefálica Profunda/métodos , Haplorrinos , Córtex Motor/fisiologia , Núcleo Subtalâmico/fisiologia
3.
Spine (Phila Pa 1976) ; 45(24): 1736-1742, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-33230084

RESUMO

STUDY DESIGN: Retrospective review. OBJECTIVE: The aim of this study was to analyze the political contributions and strategies of the Political Action Committee (PACs) lobbying for the political interests of spine surgeons. SUMMARY OF BACKGROUND DATA: In 2016, a presidential election year, $514,224,628 was spent on health care lobbying. Only 16% ($85,061,148) was on behalf of health professionals providing care. Below we chronicle the overlapping contributions between the three different physician-based Political Action Committee (PAC) lobbying entities as it relates specifically to spine surgery. METHODS: Data were abstracted for the PACs of the American Association of Neurological Surgeons (AANS), American Association of Orthopedic Surgeons (AAOS), and the North American Spine Society (NASS). These data were obtained using OpenSecrets (opensecrets.org), and the Federal Election Commission (fec.gov) website. All data points were collected biannually from 2006 to 2018 and statistically analyzed as appropriate. RESULTS: In 2016, the AAOS PAC contributed $2,648,218, the AANS PAC $348,091, and the NASS PAC $183,612. After accounting for respective group size, the AAOS spent >2.34 times that of the AANS. Orthopedists were 3.84 times (95% confidence interval 3.42-4.3) more likely to donate to their PAC than neurosurgeons (P < 0.001) during the 2016 election. The majority of contributions among the three different lobbyist organizations were to federal candidates, followed by fundraising committees, and finally to the national party. Eighty-eight percent of AANS donations went to Republican candidates, whereas AAOS and NASS were 63% and 67%, respectively. From 2008 to 2016, the AAOS PAC had a highest political contributions spend per active member of parent organization ($126.39) as compared to AANS ($80.52) and NASS ($17.81). The AAOS had five surgeons for every donor to the AAOS PAC, whereas the AANS had 14 surgeons and NASS 38 members per each donor. The AANS had a higher percentage of Republican donations with 78.9% of donations going to Republicans as compared to 61.8% of AAOS contributions and 67.9% of NASS contributions. CONCLUSION: Spine surgery is unique in that three different physician-based lobbyist organizations seek to influence legislative priorities with the AAOS having the most substantial fiscal impact and greatest participation. Choreography of donation strategies is essential to maximize physician voice at the policy level. LEVEL OF EVIDENCE: 5.


Assuntos
Manobras Políticas , Neurocirurgiões/economia , Ativismo Político , Sociedades Médicas/economia , Doenças da Coluna Vertebral/economia , Doenças da Coluna Vertebral/cirurgia , Atenção à Saúde/economia , Atenção à Saúde/métodos , Humanos , Estudos Retrospectivos , Doenças da Coluna Vertebral/epidemiologia , Estados Unidos/epidemiologia
4.
Front Surg ; 7: 55, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33062638

RESUMO

Background: Deep brain stimulation (DBS) is a therapy for movement disorders and psychiatric conditions. In the peri-operative period, brain shift occurs as the consequence of events related to the brain surgery which results in post-operative lead deformation. Objective: To quantify post-operative 3-dimensional DBS lead deformation after implantation. Methods: In 13 patients who had DBS lead implantation, we performed preoperative magnetic resonance imaging (MRI), preoperative computed tomography (CT) scans after placement of fiducial markers, and post-operative CT scans immediately, 24-48 h, and 7 days after implantation. The MRI scans were used to define brain orientation and merged with CT scans. Lead deviation was determined relative to a theoretical linear lead path defined by the skull entry and target lead tip points. Results: In the sagittal plane, we distinguished an initial period after surgery (<48 h) characterized by a deviation of the lead toward the rostral direction and a late period (over 1 week) characterized by a lead deviation toward the caudal direction. In the coronal plane, there was higher probability of lead deviation in the lateral than medial direction. During 7 days after implantation, there was net movement of the center of the lead anteriorly, and the half of the lead close to the entry point moved medially. These deviations appeared normative since all patients included in this study had benefits from DBS therapy with total power of charged comparable to those described in literature. Conclusion: DBS lead deviation occurs during 7 days after implantation. The range of deviation described in this study was not associated to adverse clinical effects and may be considered normative. Future multicenter studies would be helpful to define guide lines on DBS lead deformation and its contribution to clinical outcome.

5.
Front Neurol ; 11: 439, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32582003

RESUMO

Background and Purpose: The growth and eventual rupture of intracranial aneurysms may be due to an underlying inflammatory process as evidenced by pathological examination of aneurysm walls. We hypothesize that unruptured aneurysms have an increased inflammatory milieu within their lumen in comparison to the rest of the cerebral arterial vascular system. Methods: Blood was sampled from unruptured aneurysms in patients presenting for aneurysm coil embolization and C3 and C4 complement values from this serum were compared with complement values in the parent artery. Results: Ten patients were enrolled over 32 months with a mean aneurysm size of 9.1 mm. Compared to control samples drawn from peripheral circulation, there were significant decreases of both C3 (p = 0.0003) and C4 (p = 0.0063) levels in aneurysmal blood samples. Conclusions: A state of decreased complement indicative of classic pathway activation was found in all tested aneurysms, thus providing evidence of an ongoing process of complement activation in the blood of live, unruptured aneurysm sacs.

6.
Int J Neural Syst ; 30(2): 2050010, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32019380

RESUMO

The changes in neuronal firing activity in the primary motor cortex (M1) and supplementary motor area (SMA) were compared in monkeys rendered parkinsonian by treatment with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine. The neuronal dynamic was characterized using mathematical tools defined in different frameworks (rate, oscillations or complex patterns). Then, and for each cortical area, multivariate and discriminate analyses were further performed on these features to identify those important to differentiate between the normal and the pathological neuronal activity. Our results show a different order in the importance of the features to discriminate the pathological state in each cortical area which suggests that the M1 and the SMA exhibit dissimilarities in their neuronal alterations induced by parkinsonism. Our findings highlight the need for multiple mathematical frameworks to best characterize the pathological neuronal activity related to parkinsonism. Future translational studies are warranted to investigate the causal relationships between cortical region-specificities, dominant pathological hallmarks and symptoms.


Assuntos
Potenciais de Ação , Córtex Motor/fisiopatologia , Neurônios/fisiologia , Transtornos Parkinsonianos/fisiopatologia , 1-Metil-4-Fenil-1,2,3,6-Tetra-Hidropiridina , Potenciais de Ação/fisiologia , Animais , Ondas Encefálicas , Feminino , Modelos Lineares , Macaca fuscata , Masculino , Microeletrodos , Análise Multivariada , Dinâmica não Linear , Análise de Componente Principal , Processamento de Sinais Assistido por Computador
7.
Neurosci Res ; 156: 66-79, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31991205

RESUMO

The present study compares the cortical local field potentials (LFPs) in the primary motor cortex (M1) and the supplementary motor area (SMA) of non-human primates rendered Parkinsonian with administration of dopaminergic neurotoxin, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine. The dynamic of the LFPs was investigated under several mathematical frameworks and machine learning was used to discriminate the recordings based on these features between healthy, parkinsonian with off-medication and parkinsonian with on-medication states. The importance of each feature in the discrimination process was further investigated. The dynamic of the LFPs in M1 and SMA was affected regarding its variability (time domain analysis), oscillatory activities (frequency domain analysis) and complex patterns (non-linear domain analysis). Machine learning algorithms achieved accuracy near 0.90 for comparisons between conditions. The TreeBagger algorithm provided best accuracy. The relative importance of these features differed with the cortical location, condition and treatment. Overall, the most important features included beta oscillation, fractal dimension, gamma oscillation, entropy and asymmetry of amplitude fluctuation. The importance of features in discriminating between normal and pathological states, and on- or off-medication states depends on the pair-comparison and it is region-specific. These findings are discussed regarding the refinement of current models for movement disorders and the development of on-demand therapies.


Assuntos
Córtex Motor , Transtornos Parkinsonianos , Animais , Macaca mulatta , Aprendizado de Máquina
8.
Remote Sens Environ ; 2332019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31708597

RESUMO

The Ice, Cloud, and land Elevation Satellite - 2 (ICESat-2) observatory was launched on 15 September 2018 to measure ice sheet and glacier elevation change, sea ice freeboard, and enable the determination of the heights of Earth's forests. ICESat-2's laser altimeter, the Advanced Topographic Laser Altimeter System (ATLAS) uses green (532 nm) laser light and single-photon sensitive detection to measure time of flight and subsequently surface height along each of its six beams. In this paper, we describe the major components of ATLAS, including the transmitter, the receiver and the components of the timing system. We present the major components of the ICESat-2 observatory, including the Global Positioning System, star trackers and inertial measurement unit. The ICESat-2 Level 1B data product (ATL02) provides the precise photon round-trip time of flight, among other data. The ICESat-2 Level 2A data product (ATL03) combines the photon times of flight with the observatory position and attitude to determine the geodetic location (i.e. the latitude, longitude and height) of the ground bounce point of photons detected by ATLAS. The ATL03 data product is used by higher-level (Level 3A) surface-specific data products to determine glacier and ice sheet height, sea ice freeboard, vegetation canopy height, ocean surface topography, and inland water body height.

9.
J Neurosurg ; 131(1): 304-310, 2019 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-30771763

RESUMO

On May 5, 1961, Alan B. Shepard Jr. piloted the Freedom 7 craft into a suborbital flight to become the first American man in space. His promising astronautical career was soon scuttled by spells of dizziness and tinnitus later diagnosed as Ménière's disease, until William F. House-considered the father of neurotology and a pioneer in surgery for vestibular schwannomas-intervened. In 1968 House implanted an endolymphatic-subarachnoid shunt, which at the time was a virtually experimental procedure. Shepard's debilitating Ménière's disease was cured, but not quite in time for him to pilot the doomed Apollo 13 mission; he was reassigned to Apollo 14 and as a result would step foot on the moon on February 5, 1971. This historical vignette depicts the tale of how the career trajectories of Shepard and House-two notable figures in their respective fields-fatefully intersected.

10.
J Neurosurg Spine ; 31(1): 87-92, 2019 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-30797203

RESUMO

In 1961, President John F. Kennedy declared that the United States would send a man to the moon and safely bring him home before the end of the decade. Astronaut Michael Collins was one of those men. He flew to the moon on the historic flight of Apollo 11 while Neil Armstrong and Buzz Aldrin walked on its surface. However, this was not supposed to be the case.Astronaut Collins was scheduled to fly on Apollo 8. While training, in 1968, he started developing symptoms of cervical myelopathy. He underwent evaluation at Wilford Hall Air Force Hospital in San Antonio and was noted to have a C5-6 disc herniation and posterior osteophyte on myelography. Air Force Lieutenant General (Dr.) Paul W. Myers performed an anterior cervical discectomy with placement of iliac bone graft. As a result, Astronaut James Lovell took his place on Apollo 8 flying the uncertain and daring first mission to the moon. This had a cascading effect on the rotation of astronauts, placing Michael Collins on the Apollo 11 flight that first landed men on the moon. It also placed Astronaut James Lovell in a rotation that exposed him to be the Commander of the fateful Apollo 13 flight.Here, the authors chronicle the history of Astronaut Collins' anterior cervical surgery and the impact of his procedure on the rotation of astronaut flight selection, and they review the pivotal historic nature of the Apollo 8 spaceflight. The authors further discuss the ongoing issue of cervical disc herniation among astronauts.


Assuntos
Astronautas , Vértebras Cervicais/cirurgia , Pessoas Famosas , Voo Espacial/história , Fusão Vertebral/história , Adulto , História do Século XX , Humanos , Deslocamento do Disco Intervertebral/etiologia , Deslocamento do Disco Intervertebral/história , Deslocamento do Disco Intervertebral/cirurgia , Masculino , Doenças da Medula Espinal/etiologia , Doenças da Medula Espinal/história , Doenças da Medula Espinal/cirurgia , Estados Unidos
11.
J Pediatr Neurosci ; 14(4): 225-227, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31908665

RESUMO

Schizencephaly is a rare type of neuronal migration disorder characterized by the presence of a cerebral hemispheric cleft that extends from lateral ventricles to the cortical surface of the brain. We report a rare case of prenatally diagnosed unilateral schizencephaly in a late preterm infant who manifested with rapidly progressive hydrocephalus with massive enlargement of posterior cerebrospinal fluid spaces with tonsillar herniation that was successfully treated with placement of a ventriculoperitoneal shunt.

12.
J Neurosci Methods ; 309: 55-59, 2018 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-30171882

RESUMO

BACKGROUND: Deep brain stimulation is an effective treatment for movement disorders and psychiatric conditions. Intra-operative and post-operative events can result in brain tissue deformation (i.e. subdural gaps) which may cause lead deformation and its displacement from optimal target. We developed a method to quantify postoperative lead deformation and we present two DBS cases to illustrate the phenomena of lead deformation resulting from the development of subdural gaps. NEW METHOD: We present a semi-automatic computational algorithm using Computed Tomography scanning with reconstruction to determine lead curvature relative to a theoretical straight lead between the skull entry site and lead tip. Subdural gap was quantified from the CT scan. RESULTS: In 2 patients who had leads implanted, analysis of CT scans was completed within 5 min each. The maximum deviation of the observed lead from the theoretical linear path was 1.1 and 2.6 mm, and the subdural gap was 5.5 and 9.6 mL, respectively. COMPARISON WITH EXISTING METHOD(S): This is the first method allowing a comprehensive characterization of the lead deformation in situ. CONCLUSIONS: The computational algorithms provide a simple, semiautomatic method to characterize in situ lead curvature related to brain tissue deformation after lead placement.


Assuntos
Estimulação Encefálica Profunda/instrumentação , Estimulação Encefálica Profunda/métodos , Eletrodos Implantados , Tomografia Computadorizada por Raios X/métodos , Adulto , Algoritmos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Procedimentos Neurocirúrgicos/métodos , Adulto Jovem
13.
World Neurosurg ; 108: 317-324, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28887282

RESUMO

BACKGROUND: Burst fractures involve the anterior and middle columns with an intact posterior column. Deforming forces are magnified at areas of transition, making the thoracolumbar junction highly susceptible to injury. METHODS: This is a retrospective review of 42 consecutive patients who underwent single-level anterior lumbar corpectomy using an obelisc expandable titanium cage and lateral fixation for traumatic lumbar burst fractures. RESULTS: Myelopathy and sensory dysfunction were the most frequent neurologic deficits initially, occurring in 16 (38%) and 15 (36%) patients, respectively, which both decreased to 5 (13%). At follow-up, 26 patients (68%) were able to ambulate independently. No patient had significant cage displacement or needed cage replacement. Subsidence was minimal in 32 of 39 patients (82%). There were no hardware infections or surgical site infections. Options for stabilization include posterior instrumentation and fusion, anterior corpectomy with interbody fusion, and combination procedures. We believe anterior stabilization is superior because the aim is structural restoration of anterior and middle columns. The aim of posterior fixation is to replace the posterior tension band, which is not affected. There are 3 major surgical components to consider. First is anterior versus posterior decompression of the spinal canal. Second is the choice of autograft or titanium graft. Third is whether to stabilize posteriorly or anterolateral. CONCLUSIONS: Anterior corpectomy with an expandable titanium cage and lateral rod fixation is safe and effective with minimal complications. It is a viable alternative to posterior decompression and instrumentation.


Assuntos
Fixação Interna de Fraturas , Fixadores Internos , Vértebras Lombares/cirurgia , Procedimentos de Cirurgia Plástica , Fraturas da Coluna Vertebral/cirurgia , Titânio , Adolescente , Adulto , Idoso , Descompressão Cirúrgica , Discotomia , Desenho de Equipamento , Feminino , Seguimentos , Humanos , Vértebras Lombares/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Doenças da Medula Espinal/diagnóstico por imagem , Doenças da Medula Espinal/etiologia , Doenças da Medula Espinal/cirurgia , Fraturas da Coluna Vertebral/complicações , Fraturas da Coluna Vertebral/diagnóstico por imagem , Resultado do Tratamento , Adulto Jovem
14.
Front Hum Neurosci ; 10: 431, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27625601

RESUMO

This study describes a cost-effective screening protocol for parkinsonism based on combined objective and subjective monitoring of balance function. Objective evaluation of balance function was performed using a game industry balance board and an automated analyses of the dynamic of the center of pressure in time, frequency, and non-linear domains collected during short series of stand up tests with different modalities and severity of sensorial deprivation. The subjective measurement of balance function was performed using the Dizziness Handicap Inventory questionnaire. Principal component analyses on both objective and subjective measurements of balance function allowed to obtained a specificity and selectivity for parkinsonian patients (vs. healthy subjects) of 0.67 and 0.71 respectively. The findings are discussed regarding the relevance of cost-effective balance-based screening system as strategy to meet the needs of broader and earlier screening for parkinsonism in communities with limited access to healthcare.

16.
J Reprod Med ; 61(11-12): 609-11, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-30230290

RESUMO

Background: Folate supplementation in women of reproductive age has a well-established role in the prevention of neural tube defects. Methotrexate is a commonly used drug which functions by inhibiting normal folate metabolism in active cells. An association between fetal methotrexate exposure and myelomeningocele might be expected, considering this relationship. However, to our knowledge, no cases of myelomeningocele secondary to in utero methotrexate exposure have been reported. Case: We present the case of a gravid patient who, having received methotrexate for management of an ectopic pregnancy, was lost to follow-up and returned several weeks later carrying an intrauterine pregnancy. The fetus was found prenatally to be suffering from multiple congenital anomalies. At birth the infant demonstrated many of the abnormalities commonly associated with fetal methotrexate syndrome, including craniosynostosis and talipes equinovarus. Most interestingly, the newborn was also diagnosed with a lumbar myelomeningocele and concomitant type II Chiari malformation, as is often associated with such a neural tube defect. Conclusion: Methotrexate exposure may impact the fetal risk of myelomeningocele. Patients should be counseled thoroughly on the importance of follow-up care.


Assuntos
Anencefalia/induzido quimicamente , Antagonistas do Ácido Fólico/efeitos adversos , Meningomielocele/induzido quimicamente , Metotrexato/efeitos adversos , Anormalidades Induzidas por Medicamentos , Anencefalia/diagnóstico por imagem , Feminino , Humanos , Lactente , Recém-Nascido , Metotrexato/administração & dosagem , Gravidez , Gravidez Ectópica
17.
Am J Perinatol ; 31(4): 345-52, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23873117

RESUMO

In extremely low birth weight (ELBW) infants, levels of hypercapnia (Paco 2) > 60 mm Hg are considered a risk factor for severe intraventricular hemorrhage (IVH). Since cerebral vasoreactivity depends on arterial pH (apH) rather than Paco 2, we hypothesize that the role of mild-to-moderate hypercapnia (45-60 mm Hg) in the occurrence of severe IVH is modulated by the metabolic component of acid-base status. ELBW infants (n = 580, born < 28 wk gestation, and BW < 1,000 g) were separated into "high-base deficit (BD)" (n = 291) and "low-BD" (n = 289) groups if infants' median BD were > 4 mEq/L or ≤4 mEq/L, respectively. Rates of severe IVH were higher in "high-BD" (16%) than "low-BD" (9%) group. Although adjusted risk for severe IVH increased with higher Paco 2 and higher BD, apH was the sole predictor of severe IVH. In ELBW infants, higher degree of acidemia, rather than hypercapnia per se, during the first 48 hours of life, is associated with higher occurrences of severe IVH.


Assuntos
Acidose/epidemiologia , Hemorragia Cerebral/epidemiologia , Ventrículos Cerebrais , Hipercapnia/epidemiologia , Feminino , Humanos , Recém-Nascido de Peso Extremamente Baixo ao Nascer , Lactente Extremamente Prematuro , Recém-Nascido , Masculino , Estudos Retrospectivos , Fatores de Risco , Índice de Gravidade de Doença
18.
Biomed Res Int ; 2013: 742671, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23762856

RESUMO

During this last decade, nonlinear analyses have been used to characterize the irregularity that exists in the neuronal data stream of the basal ganglia. In comparison to linear parameters for disparity (i.e., rate, standard deviation, and oscillatory activities), nonlinear analyses focus on complex patterns that are composed of groups of interspike intervals with matching lengths but not necessarily contiguous in the data stream. In light of recent animal and clinical studies, we present a review and commentary on the basal ganglia neuronal entropy in the context of movement disorders.


Assuntos
Gânglios da Base/fisiopatologia , Entropia , Modelos Neurológicos , Transtornos dos Movimentos/fisiopatologia , Animais , Humanos , Neurônios/patologia , Dinâmica não Linear
20.
Front Neurol ; 4: 211, 2013 Dec 25.
Artigo em Inglês | MEDLINE | ID: mdl-24399994

RESUMO

Over the last 30 years, the functions (and dysfunctions) of the sensory-motor circuitry have been mostly conceptualized using linear modelizations which have resulted in two main models: the "rate hypothesis" and the "oscillatory hypothesis." In these two models, the basal ganglia data stream is envisaged as a random temporal combination of independent simple patterns issued from its probability distribution of interval interspikes or its spectrum of frequencies respectively. More recently, non-linear analyses have been introduced in the modelization of motor circuitry activities, and they have provided evidences that complex temporal organizations exist in basal ganglia neuronal activities. Regarding movement disorders, these complex temporal organizations in the basal ganglia data stream differ between conditions (i.e., parkinsonism, dyskinesia, healthy control) and are responsive to treatments (i.e., l-DOPA, deep brain stimulation). A body of evidence has reported that basal ganglia neuronal entropy (a marker for complexity/irregularity in time series) is higher in hypokinetic state. In line with these findings, an entropy-based model has been recently formulated to introduce basal ganglia entropy as a marker for the alteration of motor processing and a factor of motor inhibition. Importantly, non-linear features have also been identified as a marker of condition and/or treatment effects in brain global signals (EEG), muscular activities (EMG), or kinetic of motor symptoms (tremor, gait) of patients with movement disorders. It is therefore warranted that the non-linear dynamics of motor circuitry will contribute to a better understanding of the neuronal dysfunctions underlying the spectrum of parkinsonian motor symptoms including tremor, rigidity, and hypokinesia.

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