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1.
World Neurosurg ; 2020 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-32298832

RESUMO

BACKGROUND: Stereotactic localization of neurosurgical targets traditionally relies on computed tomography (CT), which is considered the optimal imaging modality for geometric accuracy. However, in-depth investigations that characterize the precision and accuracy of CT images are lacking. We used a CT phantom to examine interscanner precision and interprotocol accuracy in coordinate localization. METHODS: A polymethylacrylate phantom was scanned with Toshiba Aquilion 64 and GE Healthcare LightSpeed 16 CT scanners, using both helical and incremental single-slice (SS) image acquisition protocols. The X, Y, and Z coordinates of 94 points across 6 surfaces of the phantom were physically measured. The CT scan-derived coordinates were compared with the phantom coordinates and with each other to determine accuracy and precision, respectively. RESULTS: Using the SS imaging protocol, the mean (SD) interscanner disparity in localization was 0.93 (0.39) mm, given by the average Euclidean distance between the coordinates of the 2 scanners. This discrepancy significantly varied by axis and surface, with the greatest discrepancy in the Z-axis of 0.30 mm (95% confidence interval, 0.25-0.35; P = 0.05) and on the superior surface of 1.30 mm (95% confidence interval, 1.15-1.45; P = 0.05). SS acquisition was significantly more accurate than the helical protocol. CONCLUSIONS: We found evidence of clinically relevant inconsistency between 2 CT scanners used for stereotactic localization. SS image acquisition was superior to helical scanning with respect to localization accuracy. Interscanner consistency cannot be assumed. Institutions would benefit from identifying the errors inherent in their CT scanners.

2.
Neurosurg Focus ; 48(2): E2, 2020 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-32006952

RESUMO

OBJECTIVE: Stimulation of the primary somatosensory cortex (S1) has been successful in evoking artificial somatosensation in both humans and animals, but much is unknown about the optimal stimulation parameters needed to generate robust percepts of somatosensation. In this study, the authors investigated frequency as an adjustable stimulation parameter for artificial somatosensation in a closed-loop brain-computer interface (BCI) system. METHODS: Three epilepsy patients with subdural mini-electrocorticography grids over the hand area of S1 were asked to compare the percepts elicited with different stimulation frequencies. Amplitude, pulse width, and duration were held constant across all trials. In each trial, subjects experienced 2 stimuli and reported which they thought was given at a higher stimulation frequency. Two paradigms were used: first, 50 versus 100 Hz to establish the utility of comparing frequencies, and then 2, 5, 10, 20, 50, or 100 Hz were pseudorandomly compared. RESULTS: As the magnitude of the stimulation frequency was increased, subjects described percepts that were "more intense" or "faster." Cumulatively, the participants achieved 98.0% accuracy when comparing stimulation at 50 and 100 Hz. In the second paradigm, the corresponding overall accuracy was 73.3%. If both tested frequencies were less than or equal to 10 Hz, accuracy was 41.7% and increased to 79.4% when one frequency was greater than 10 Hz (p = 0.01). When both stimulation frequencies were 20 Hz or less, accuracy was 40.7% compared with 91.7% when one frequency was greater than 20 Hz (p < 0.001). Accuracy was 85% in trials in which 50 Hz was the higher stimulation frequency. Therefore, the lower limit of detection occurred at 20 Hz, and accuracy decreased significantly when lower frequencies were tested. In trials testing 10 Hz versus 20 Hz, accuracy was 16.7% compared with 85.7% in trials testing 20 Hz versus 50 Hz (p < 0.05). Accuracy was greater than chance at frequency differences greater than or equal to 30 Hz. CONCLUSIONS: Frequencies greater than 20 Hz may be used as an adjustable parameter to elicit distinguishable percepts. These findings may be useful in informing the settings and the degrees of freedom achievable in future BCI systems.

3.
Artigo em Inglês | MEDLINE | ID: mdl-31584102

RESUMO

BACKGROUND: Three-dimensional fluoroscopy via the O-arm (Medtronic, Dublin, Ireland) has been validated for intraoperative confirmation of successful lead placement in stereotactic electrode implantation. However, its role in registration and targeting has not yet been studied. After frame placement, many stereotactic neurosurgeons obtain a computed tomography (CT) scan and merge it with a preoperative magnetic resonance imaging (MRI) scan to generate planning coordinates; potential disadvantages of this practice include increased procedure time and limited scanner availability. OBJECTIVE: To evaluate whether the second-generation O-arm (O2) can be used in lieu of a traditional CT scan to obtain accurate frame-registration scans. METHODS: In 7 patients, a postframe placement CT scan was merged with preoperative MRI and used to generate lead implantation coordinates. After implantation, the fiducial box was again placed on the patient to obtain an O2 confirmation scan. Vector, scalar, and Euclidean differences between analogous X, Y, and Z coordinates from fused O2/MRI and CT/MRI scans were calculated for 33 electrode target coordinates across 7 patients. RESULTS: Marginal means of difference for vector (X = -0.079 ± 0.099 mm; Y = -0.076 ± 0.134 mm; Z = -0.267 ± 0.318 mm), scalar (X = -0.146 ± 0.160 mm; Y = -0.306 ± 0.106 mm; Z = 0.339 ± 0.407 mm), and Euclidean differences (0.886 ± 0.190 mm) remained within the predefined equivalence margin differences of -2 mm and 2 mm. CONCLUSION: This study demonstrates that O2 may emerge as a viable alternative to the traditional CT scanner for generating planning coordinates. Adopting the O2 as a perioperative tool may offer reduced transport risks, decreased anesthesia time, and greater surgical efficiency.

4.
J Clin Neurosci ; 68: 13-19, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31375306

RESUMO

Implantable neurostimulation devices provide a direct therapeutic link to the nervous system and can be considered brain-computer interfaces (BCI). Under this definition, BCI are not simply science fiction, they are part of existing neurosurgical practice. Clinical BCI are standard of care for historically difficult to treat neurological disorders. These systems target the central and peripheral nervous system and include Vagus Nerve Stimulation, Responsive Neurostimulation, and Deep Brain Stimulation. Recent advances in clinical BCI have focused on creating "closed-loop" systems. These systems rely on biomarker feedback and promise individualized therapy with optimal stimulation delivery and minimal side effects. Success of clinical BCI has paralleled research efforts to create BCI that restore upper extremity motor and sensory function to patients. Efforts to develop closed loop motor/sensory BCI is linked to the successes of today's clinical BCI.


Assuntos
Interfaces Cérebro-Computador/tendências , Estimulação Encefálica Profunda/tendências , Doenças do Sistema Nervoso/terapia , Estimulação do Nervo Vago/tendências , Estimulação Encefálica Profunda/instrumentação , Estimulação Encefálica Profunda/métodos , Humanos , Estimulação do Nervo Vago/instrumentação , Estimulação do Nervo Vago/métodos
5.
Front Neurosci ; 13: 832, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31440133

RESUMO

Recently, efforts to produce artificial sensation through cortical stimulation of primary somatosensory cortex (PSC) in humans have proven safe and reliable. Changes in stimulation parameters like frequency and amplitude have been shown to elicit different percepts, but without clearly defined psychometric profiles. This study investigates the functionally useful limits of frequency changes on the percepts felt by three epilepsy patients with subdural electrocorticography (ECoG) grids. Subjects performing a hidden target task were stimulated with parameters of constant amplitude, pulse-width, and pulse-duration, and a randomly selected set of two frequencies (20, 30, 40, 50, 60, and 100 Hz). They were asked to decide which target had the "higher" frequency. Objectively, an increase in frequency differences was associated with an increase in perceived intensity. Reliable detection of stimulation occurred at and above 40 Hz with a lower limit of detection around 20 Hz and a just-noticeable difference estimated at less than 10 Hz. These findings suggest that frequency can be used as a reliable, adjustable parameter and may be useful in establishing settings and thresholds of functionality in future BCI systems.

6.
J Clin Neurosci ; 64: 214-219, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31023574

RESUMO

Previous work in directional tuning for brain machine interfaces has primarily relied on algorithm sorted neuronal action potentials in primary motor cortex. However, local field potential has been utilized to show directional tuning in macaque studies, and inferior parietal cortex has shown increased neuronal activity in reaching tasks that relied on MRI imaging. In this study we utilized local field potential recordings from a human subject performing a delayed reach task and show that high frequency band (76-100 Hz) spectral power is directionally tuned to different reaching target locations during an active reach. We also show that during the delay phase of the task, directional tuning is present in areas of the inferior parietal cortex, in particular, the supramarginal gyrus.


Assuntos
Potenciais de Ação/fisiologia , Lobo Parietal/fisiologia , Desempenho Psicomotor/fisiologia , Adulto , Humanos , Masculino , Córtex Motor/fisiologia , Neurônios/fisiologia
7.
Neurosurg Clin N Am ; 30(2): 275-281, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30898278

RESUMO

Brain-computer interfaces (BCI) are implantable devices that interface directly with the nervous system. BCI for quadriplegic patients restore function by reading motor intent from the brain and use the signal to control physical, virtual, and native prosthetic effectors. Future closed-loop motor BCI will incorporate sensory feedback to provide patients with an effective and intuitive experience. Development of widely available BCI for patients with neurologic injury will depend on the successes of today's clinical BCI. BCI are an exciting next step in the frontier of neuromodulation.


Assuntos
Interfaces Cérebro-Computador , Encéfalo/fisiopatologia , Quadriplegia/reabilitação , Humanos , Quadriplegia/fisiopatologia
8.
World Neurosurg ; 126: 496, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30922896

RESUMO

Revascularization is an important strategy when treating cerebrovascular occlusive disease and complex aneurysms. Radial artery fascial flow-through free flaps (RAFFs) are flexible grafts that provide direct and indirect revascularization. RAFFs can be especially useful for large territory revascularization and can be combined with other direct bypasses. Although common in plastic and reconstructive surgery, RAFF neurosurgical applications have rarely been described. The 3-dimensional video presents a 47-year-old man with watershed infarcts on imaging who presented with right-sided weakness (Video 1). Vessel imaging was significant for bilateral internal carotid artery (ICA) terminus stenosis. The left middle cerebral artery (MCA) ended in a fusiform aneurysm of the M1 segment. The left anterior cerebral artery (ACA) also had a smaller fusiform aneurysm at the A1/2 junction. A perfusion study demonstrated an increased mean transit time in the left MCA territory. Given the patient's age, his symptomatic ischemia, and enlarging MCA aneurysm, he was recommended for a combined revascularization and left ICA occlusion. A left facial artery-to-MCA bypass using the right posterior tibial artery was performed for direct MCA revascularization. A left superficial temporal artery-to-ACA bypass with a RAFF was performed for direct ACA and indirect MCA territory revascularization. Postoperative angiography demonstrated patency of both direct grafts. The patient suffered small pericallosal infarcts because of retraction and perforator sacrifice at the revascularization site. At early follow-up, the patient was at his neurologic baseline, and at 1-year follow up, the patient had no additional infarcts on imaging and was living independently.


Assuntos
Revascularização Cerebral/métodos , Transtornos Cerebrovasculares/cirurgia , Aneurisma Intracraniano/cirurgia , Procedimentos Neurocirúrgicos/métodos , Procedimentos Cirúrgicos Vasculares/métodos , Artéria Cerebral Anterior/patologia , Artéria Carótida Interna/patologia , Transtornos Cerebrovasculares/complicações , Humanos , Aneurisma Intracraniano/complicações , Masculino , Pessoa de Meia-Idade , Artéria Cerebral Média/patologia , Resultado do Tratamento
9.
J Clin Neurosci ; 63: 116-121, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30711286

RESUMO

Somatosensory feedback is the next step in brain computer interface (BCI). Here, we compare three cortical stimulating array modalities for generating somatosensory percepts in BCI. We compared human subjects with either a 64-channel "mini"-electrocorticography grid (mECoG; 1.2-mm diameter exposed contacts with 3-mm spacing, N = 1) over the hand area of primary somatosensory cortex (S1), or a standard grid (sECoG; 1.5-mm diameter exposed contacts with 1-cm spacing, N = 1), to generate artificial somatosensation through direct electrical cortical stimulation. Finally, we reference data in the literature from a patient implanted with microelectrode arrays (MEA) placed in the S1 hand area. We compare stimulation results to assess coverage and specificity of the artificial percepts in the hand. Using the mECoG array, hand mapping revealed coverage of 41.7% of the hand area versus 100% for the sECoG array, and 18.8% for the MEA. On average, stimulation of a single electrode corresponded to sensation reported in 4.42 boxes (range 1-11 boxes) for the mECoG array, 19.11 boxes (range 4-48 boxes) for the sECoG grid, and 2.3 boxes (range 1-5 boxes) for the MEA. Sensation in any box, on average, corresponded to stimulation from 2.65 electrodes (range 1-5 electrodes) for the mECoG grid, 3.58 electrodes for the sECoG grid (range 2-4 electrodes), and 11.22 electrodes (range 2-17 electrodes) for the MEA. Based on these findings, we conclude that mECoG grids provide an excellent balance between spatial cortical coverage of the hand area of S1 and high-density resolution.


Assuntos
Interfaces Cérebro-Computador , Estimulação Elétrica/métodos , Córtex Somatossensorial/fisiologia , Mapeamento Encefálico/métodos , Eletrocorticografia/métodos , Eletrodos Implantados , Mãos/inervação , Humanos , Microeletrodos , Sensação
10.
Exp Brain Res ; 237(5): 1155-1167, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30796470

RESUMO

OBJECTIVE: Restoration of somatosensory deficits in humans requires a clear understanding of the neural representations of percepts. To characterize the cortical response to naturalistic somatosensation, we examined field potentials in the primary somatosensory cortex of humans. METHODS: Four patients with intractable epilepsy were implanted with subdural electrocorticography (ECoG) electrodes over the hand area of S1. Three types of stimuli were applied, soft-repetitive touch, light touch, and deep touch. Power in the alpha (8-15 Hz), beta (15-30 Hz), low-gamma (30-50 Hz), and high-gamma (50-125 Hz) frequency bands were evaluated for significance. RESULTS: Seventy-seven percent of electrodes over the hand area of somatosensory cortex exhibited changes in these bands. High-gamma band power increased for all stimuli, with concurrent alpha and beta band power decreases. Earlier activity was seen in these bands in deep touch and light touch compared to soft touch. CONCLUSIONS: These findings are consistent with prior literature and suggest a widespread response to focal touch, and a different encoding of deeper pressure touch than soft touch.


Assuntos
Ondas Encefálicas/fisiologia , Eletrocorticografia/métodos , Mãos/fisiologia , Córtex Somatossensorial/fisiologia , Adulto , Estimulação Elétrica , Eletrodos Implantados , Epilepsia/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
11.
J Neurosurg ; : 1-7, 2019 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-30684944

RESUMO

Closed-loop brain-responsive neurostimulation via the RNS System is a treatment option for adults with medically refractory focal epilepsy. Using a novel technique, 2 RNS Systems (2 neurostimulators and 4 leads) were successfully implanted in a single patient with bilateral parietal epileptogenic zones. In patients with multiple epileptogenic zones, this technique allows for additional treatment options. Implantation can be done successfully, without telemetry interference, using proper surgical planning and neurostimulator positioning.Trajectories for the depth leads were planned using neuronavigation with CT and MR imaging. Stereotactic frames were used for coordinate targeting. Each neurostimulator was positioned with maximal spacing to avoid telemetry interference while minimizing patient discomfort. A separate J-shaped incision was used for each neurostimulator to allow for compartmentalization in case of infection. In order to minimize surgical time and risk of infection, the neurostimulators were implanted in 2 separate surgeries, approximately 3 weeks apart.The neurostimulators and leads were successfully implanted without adverse surgical outcomes. The patient recovered uneventfully, and the early therapy settings over several months resulted in preliminary decreases in aura and seizure frequency. Stimulation by one of the neurostimulators did not result in stimulation artifacts detected by the contralateral neurostimulator.

12.
Epilepsy Res ; 137: 101-106, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28985613

RESUMO

BACKGROUND: Inpatient hospital stays for patients with epilepsy represent a significant burden on patients and society. Identifying factors that contribute to such costs aides in developing effective strategies to address this burden. July admissions have been associated with higher rates of complications and worse outcomes, attributed to the presence of new physicians. This study aims to evaluate whether epilepsy patients admitted in July have higher preventable complication rates and mortality than during the rest of the year. METHODS: Data was derived from the Nationwide Inpatient Sample (NIS) for epilepsy admissions for the years 2000-2010. Multivariable analyses assessed the effect of July against non-July admission on "hospital acquired complications" (HAC), which are complications identified as owing to preventable causes and mortality. Additionally, the total adjusted charges and prolonged length of stay (pLOS) for July admissions were compared to the 50th percentile. RESULTS: A total of 12,997,181 admissions for epilepsy were identified with 993,619 (8%) occurring in July, 10,810,900 (83%) were non-July months, and 1,192,662 (9%) were missing data. Patients admitted in July showed an increased association for HAC events (RR=1.02, [1.01,1.03], p<0.01), but a decrease in mortality (RR=0.96, [0.95,0.97], p<0.01). There was no difference in rates of higher total adjusted charges for July admissions (RR=1.00, [1.00,1.00], p<0.01) and a decrease in rates of pLOS (RR=0.99, [0.98,0.99], p<0.01). CONCLUSION: In the epilepsy population, although July admissions were associated with a slight increase in HAC events, there was a non-significant or decreased rate of mortality, LOS, and total charge. Our results suggest that although complications were increased in July, possibly due to new staff, supervision is sufficient to prevent significant burden on patients and hospitals.


Assuntos
Epilepsia/mortalidade , Epilepsia/terapia , Doença Iatrogênica/epidemiologia , Doença Iatrogênica/prevenção & controle , Admissão do Paciente , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Epilepsia/complicações , Feminino , Mortalidade Hospitalar , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Análise de Regressão , Estudos Retrospectivos , Estações do Ano , Fatores de Tempo , Adulto Jovem
13.
Pediatr Neurol ; 74: 24-31.e1, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28676248

RESUMO

BACKGROUND: Pediatric epilepsy is one of the most common neurological disorders with low mortality and high morbidity, often requiring hospitalization. Weekend admissions have been shown to be associated with worse outcomes compared with their weekday counterparts. To date, no study has assessed the impact of weekend admission on clinical and quality outcomes in the pediatric epilepsy population. METHODS: Children with epilepsy were identified from the 2000, 2003, 2006, and 2009 Kids Inpatient Database. Quality outcomes were identified using the Centers of Medicare and Medicaid Services' hospital acquired conditions International Classification of Diseases, Ninth Edition; Clinical Modification (ICD-9CM) codes. Multivariable analyses were conducted to assess the association between weekend admission and inpatient mortality and hospital acquired condition occurrence. RESULTS: A total of 526,765 pediatric epilepsy discharges were identified, with 80% occurring on weekdays and 20% on weekends. Overall, the hospital acquired condition rate was 3.6% (3.2% vs 5.2% for weekday versus weekend) and inpatient mortality was 1.5% (1.2% vs 1.7%). Patients admitted on the weekend had 28% higher rates of hospital acquired conditions and 21% higher inpatient mortality rates compared with their weekday counterparts. Patients seen at nonpediatric centers had 10% to 28% lower rates of mortality, but 5% to 13% higher hospital acquired condition rates than those at pediatric centers. CONCLUSIONS: Weekend admission is significantly associated with worse clinical and quality outcomes compared with weekday admissions among pediatric epilepsy inpatients. Weekend admissions likely represent unplanned, at risk admissions, coupled with less staffing. Further study is needed to isolate clinical and systemic factors to decrease this disparity in this highly comorbid pediatric subgroup.


Assuntos
Plantão Médico/métodos , Epilepsia/epidemiologia , Epilepsia/mortalidade , Mortalidade Hospitalar , Hospitalização , Adolescente , Fatores Etários , Criança , Pré-Escolar , Estudos de Coortes , Comorbidade , Bases de Dados como Assunto , Feminino , Hospitalização/estatística & dados numéricos , Humanos , Lactente , Tempo de Internação , Masculino , Pediatria , Fatores de Tempo
14.
Epilepsy Behav ; 70(Pt A): 50-56, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28410465

RESUMO

INTRODUCTION: Epilepsy affects approximately 1% of the population in the United States with frequent hospital admissions accounting for a significant burden on patients and society as a whole. Weekend admissions have generally been found to have poorer outcomes compared to weekday admissions with increased rates of preventable complications, such as nationally identified "hospital-acquired conditions" (HAC). OBJECTIVE: This study aimed to assess the impact of weekend admission on HACs and mortality in the adult epilepsy population. PARTICIPANTS: All adult patients with epilepsy hospitalized in the U.S. from 2000 to 2010 in the Nationwide Inpatient Sample. RESULTS: There were 12,997,181 admissions for epilepsy with 10,106,152 (78%) weekday, 2,891,019 (22%) weekend, and 10 (<0.1%) missing admissions. Weekend admissions saw a 10% increased likelihood of both HACs (RR=1.10, 95% CI:1.09, 1.11, p<0.01) and mortality (RR=1.10, 95% CI: 1.09, 1.11, p<0.01) compared to weekday admissions. The occurrence of HAC was associated with higher inpatient charges (RR=1.36, 95% CI: 1.35, 1.36, p<0.01), pLOS (RR=1.21, 95% CI: 1.21, 1.22, p<0.01), and higher mortality (RR=1.13, 95% CI: 1.12, 1.14, p<0.01). CONCLUSION: Prior studies have shown weekend admissions are usually associated with higher rates of complications leading to higher costs and a longer hospital stay. Likewise, weekend admissions for epilepsy were associated with increased rates of HACs and mortality; however, they were also negatively associated with LOS and total charge. Thus, weekend admissions for epilepsy should be considered high risk with greater effort made to mitigate these risks.


Assuntos
Epilepsia/mortalidade , Epilepsia/terapia , Mortalidade Hospitalar/tendências , Admissão do Paciente/normas , Admissão do Paciente/tendências , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Bases de Dados Factuais/tendências , Epilepsia/diagnóstico , Feminino , Humanos , Tempo de Internação/tendências , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Fatores de Tempo , Estados Unidos/epidemiologia , Adulto Jovem
15.
Stereotact Funct Neurosurg ; 95(1): 1-5, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28088802

RESUMO

Cortical spreading depolarization (CSD) is an electrophysiologic phenomenon found mostly in the setting of neurologic injury resulting in the disturbance of ion homeostasis and leading to changes in the local vascular response. The bioelectric etiology of CSD shares similarities to those in epileptic disorders, yet the relationship between seizures and CSD is unclear, with several studies observing cortical depression before, during, and after seizure activity, thus obscuring our understanding of whether CSD activity potentiates or limits seizures and vice versa. Cortical sampling has exhibited how the redistribution of ion concentrations in the intra- and extracellular environments interplay between the excitation of seizures and the electrical depression of CSD. Modeling of both environments has suggested that CSD synchronizes the affected tissue, creating a favorable environment for seizure activity; however, other studies have demonstrated the opposite: epileptiform activity initiating waves of CSD. Further studies have underscored the role of the vascular response and subsequent ischemia in CSD that contributes to epileptogenesis. Investigations in migraine, traumatic brain injury, and other neurologic injuries suggest that several drugs may target CSD. Manipulations in the occurrence and nature of CSD can potentially alter the threshold for seizure activity, and perhaps minimize immediate and long-term sequelae associated with epilepsy.


Assuntos
Córtex Cerebral/fisiopatologia , Depressão Alastrante da Atividade Elétrica Cortical/fisiologia , Convulsões/fisiopatologia , Eletrocorticografia , Humanos
17.
J Clin Neurosci ; 31: 152-6, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27424129

RESUMO

Over the past several decades, the rate of traumatic brain injury (TBI)-related emergency room visits in the United States has steadily increased, yet mortality in these patients has decreased. This improvement in outcome is largely due to advances in prehospital care, intensive care unit management, and the effectiveness of neurosurgical procedures, such as decompressive craniectomies. It is imperative to identify clinical factors predictive of patients who benefit from early mobilization of resources and operative treatment. Equally important is the identification of patients with good prognostic signs among patients receiving surgical intervention for TBI. We conducted a retrospective chart review of 181 patients requiring craniectomies and craniotomies for decompression or evacuation of an intracranial hemorrhage following TBI at a single level I trauma center between 2008-2010. Demographic features and perioperative clinical characteristics of these patients were examined in relation to favorable outcomes, defined as discharge to home or a rehabilitation facility, and unfavorable outcomes, defined as in-hospital mortality or discharge to step-down medical facilities. Younger age, greater Glasgow Coma Scale (GCS) score on admission, absence of preoperative coagulopathies, absence of hypernatremia, and absence of fever were all independent predictors of favorable outcome. Additionally, increased operative duration and increased length of hospital stay were identified as independent predictors of negative outcomes after surgery. This work supports some of the current prognostic models in the literature and identifies additional clinical variables with predictive value of early outcome and discharge status in patients undergoing surgical evacuation of traumatic intracranial hemorrhages.


Assuntos
Hemorragia Intracraniana Traumática/cirurgia , Adolescente , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Alta do Paciente , Prognóstico , Estudos Retrospectivos , Adulto Jovem
18.
Curr Treat Options Neurol ; 18(8): 38, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27325362

RESUMO

OPINION STATEMENT: New neuroprotective treatments aimed at preventing or minimizing "delayed brain injury" are attractive areas of investigation and hold the potential to have substantial beneficial effects on aneurysmal subarachnoid hemorrhage (aSAH) survivors. The underlying mechanisms for this "delayed brain injury" are multi-factorial and not fully understood. The most ideal treatment strategies would have the potential for a pleotropic effect positively modulating multiple implicated pathophysiological mechanisms at once. My personal management (RFJ) of patients with aneurysmal subarachnoid hemorrhage closely follows those treatment recommendations contained in modern published guidelines. However, over the last 5 years, I have also utilized a novel treatment strategy, originally developed at the University of Maryland, which consists of a 14-day continuous low-dose intravenous heparin infusion (LDIVH) beginning 12 h after securing the ruptured aneurysm. In addition to its well-known anti-coagulant properties, unfractionated heparin has potent anti-inflammatory effects and through multiple mechanisms may favorably modulate the neurotoxic and neuroinflammatory processes prominent in aneurysmal subarachnoid hemorrhage. In my personal series of patients treated with LDIVH, I have found significant preservation of neurocognitive function as measured by the Montreal Cognitive Assessment (MoCA) compared to a control cohort of my patients treated without LDIVH (RFJ unpublished data presented at the 2015 AHA/ASA International Stroke Conference symposium on neuroinflammation in aSAH and in abstract format at the 2015 AANS/CNS Joint Cerebrovascular Section Annual Meeting). It is important for academic physicians involved in the management of these complex patients to continue to explore new treatment options that may be protective against the potentially devastating "delayed brain injury" following cerebral aneurysm rupture. Several of the treatment options included in this review show promise and could be carefully adopted as the level of evidence for each improves. Other proposed neuroprotective treatments like statins and magnesium sulfate were previously thought to be very promising and to varying degrees were adopted at numerous institutions based on somewhat limited human evidence. Recent clinical trials and meta-analysis have shown no benefit for these treatments, and I currently no longer utilize either treatment as prophylaxis in my practice.

19.
Neurosurg Clin N Am ; 27(2): 155-66, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27012380

RESUMO

Endovascular embolization is a frequently used adjunct to operative resection of meningiomas. Embolization may decrease intraoperative blood loss, operative time, and surgical difficulty associated with resection. The specific clinical applications of this treatment have not been defined clearly. Procedural indications, preferred embolic agent, and latency until tumor resection all differ across operators. It is clear that strategic patient selection, comprehensive anatomic understanding, and sound operative technique are critical to the success of the embolization procedure. This article reviews the management and technical considerations associated with preoperative meningioma embolization.


Assuntos
Embolização Terapêutica/métodos , Procedimentos Endovasculares/métodos , Neoplasias Meníngeas/terapia , Meningioma/terapia , Encéfalo/irrigação sanguínea , Encéfalo/cirurgia , Embolização Terapêutica/efeitos adversos , Procedimentos Endovasculares/efeitos adversos , Humanos , Neoplasias Meníngeas/irrigação sanguínea , Meningioma/irrigação sanguínea , Cuidados Pré-Operatórios , Resultado do Tratamento
20.
J Clin Neurosci ; 24: 22-7, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26461911

RESUMO

Cortical spreading depolarization (CSD) is a spreading loss of ion homeostasis, altered vascular response, change in synaptic architecture, and subsequent depression in electrical activity following an inciting neurological injury. First described by Leão in 1944, this disturbance in neuronal electrophysiology has since been demonstrated in a number of animal studies, and recently a few human studies that examine the occurrence of this depolarizing phenomenon in the setting of a variety of pathological states, including migraines, cerebrovascular accidents, epilepsy, intracranial hemorrhages, and traumatic brain injuries. The onset of CSD has been demonstrated experimentally following a disruption in the neuronal environment leading to glutamate-induced toxicity. This initial event leads to pathological changes in the activity of ion channels that maintain membrane potential. Recovery mechanisms such as sodium-potassium pumps that aim to restore homeostasis fail, leading to osmolar shifts of fluid, swelling of the neuron, and ultimately a measurable depression in cortical activity that spreads in the order of millimeters per minute. Equally important is the resulting change in vascular response. In healthy tissue, increased electrical activity is coupled with release of vasodilatory factors such as nitric oxide and arachidonic acid metabolites that increase local blood flow to meet increased energy expenditure. In damaged tissue, not only is the restorative vascular response lacking but a vasoconstrictive response is promoted and the ischemia that follows adds to the severity of the initial injury. Tissue threatened by this ischemic response is then at elevated risk for CSD propagation and falls into a vicious cycle of electrical and hemodynamic disturbance. Efforts have been made to halt this spreading cortical depression using N-methyl-D-aspartate receptor antagonists and other ion channel blockers to minimize the damaging effects of CSD that can persist long after the triggering insult.


Assuntos
Encéfalo/fisiopatologia , Depressão Alastrante da Atividade Elétrica Cortical/fisiologia , Animais , Humanos
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