Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 200
Filtrar
2.
World Neurosurg ; 2020 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-32036068

RESUMO

Anterior cervical spine surgeries have low morbidity, sufficient surgical corridor, and quick recovery times. While largely considered a safe and effective procedure to address cervical myelopathy, radiculopathy, and deformity, dysphagia is a frequent yet poorly understood adverse event. One treatment is a cricopharyngeal myotomy (CPM), which aids in swallowing for patients with refractory issues after ACDF. Here we describe our experience with 6 patients requiring revision ACDF with preoperative dysphagia who were treated with concurrent revision and CPM. Our series demonstrated that CPM is an effective and safe procedure used in combination with an ACDF. In our series we had six patients with dysphagia preoperatively who were all able to undergo ACDF without worsening of their dysphagia despite having risk factors predisposing them to this complication. In our series, 83% of patients either improved or experienced resolution of their symptoms with only one patient failing to improve. Given its efficacy and safety, patients planned for ACDF with preoperative dysphagia should be evaluated by ENT for potential CPM.

3.
J Neurosci ; 2020 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-31974207

RESUMO

The medial temporal lobe (MTL) is known as the locus of spatial coding and episodic memory, but the interaction between these cognitive domains, as well as the extent to which they rely on common neurophysiological mechanisms is poorly understood. Here, we use intracranial EEG and a hybrid spatial-episodic memory task (29 subjects, 15 female) to determine how spatial information is dynamically reactivated in sub-regions of the human MTL and how this reactivation guides recall of episodic information. Our results implicate theta oscillations across the MTL as a common neurophysiological substrate for spatial coding in navigation and episodic recall. We further show that our index of retrieved spatial context is high in the hippocampus (HC) in an early time window preceding recall. Closer to recall, it decreases in the HC and increases in the parahippocampal gyrus (PHG). Finally, we demonstrate that hippocampal theta phase modulates parahippocampal gamma amplitude during retrieval of spatial context, suggesting a role for cross frequency coupling in coding and transmitting retrieved spatial information.SIGNIFICANCE STATEMENTBy recording from the human MTL while subjects recall items experienced in a virtual environment, we establish a direct relation between the strength of theta activity during memory search and the extent to which memories are organized by their spatial locations. We thereby pinpoint a role for theta oscillations in accessing the 'cognitive map' during episodic retrieval and further highlight the dynamic interplay of hippocampus and extra-hippocampal MTL in representing retrieved spatial context. Our results provide an important step towards a unified theory of MTL function encompassing its role in spatial navigation and episodic memory.

4.
Neuroimage Clin ; 25: 102174, 2020 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-31982679

RESUMO

BACKGROUND: Anterior two-thirds corpus callosotomy is an effective palliative neurosurgical procedure for drug-refractory epilepsy that is most commonly used to treat drop-attacks. Laser interstitial thermal therapy is a novel stereotactic ablative technique that has been utilised as a minimally invasive alternative to resective and disconnective open neurosurgery. Case series have reported success in performing laser anterior two-thirds corpus callosotomy. Computer-assisted planning algorithms may help to automate and optimise multi-trajectory planning for this procedure. OBJECTIVE: To undertake a simulation-based feasibility study of computer-assisted corpus callostomy planning in comparison with expert manual plans in the same patients. METHODS: Ten patients were selected from a prospectively maintained database. Patients had previously undergone diffusion-weighted imaging and digital subtraction angiography as part of routine SEEG care. Computer-assisted planning was performed using the EpiNav™ platform and compared to manually planned trajectories from two independent blinded experts. Estimated ablation cavities were used in conjunction with probabilistic tractography to simulate the expected extent of interhemispheric disconnection. RESULTS: Computer-assisted planning resulted in significantly improved trajectory safety metrics (risk score and minimum distance to vasculature) compared to blinded external expert manual plans. Probabilistic tractography revealed residual interhemispheric connectivity in 1/10 cases following computer-assisted planning compared to 4/10 and 2/10 cases with manual planning. CONCLUSION: Computer-assisted planning successfully generates multi-trajectory plans capable of LITT anterior two-thirds corpus callosotomy. Computer-assisted planning may provide a means of standardising trajectory planning and serves as a potential new tool for optimising trajectories. A prospective validation study is now required to determine if this translates into improved patient outcomes.

5.
Curr Biol ; 30(2): 245-253.e4, 2020 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-31902728

RESUMO

The hippocampus and surrounding medial-temporal-lobe (MTL) structures are critical for both memory and spatial navigation, but we do not fully understand the neuronal representations used to support these behaviors. Much research has examined how the MTL neurally represents spatial information, such as with "place cells" that represent an animal's current location or "head-direction cells" that code for an animal's current heading. In addition to behaviors that require an animal to attend to the current spatial location, navigating to remote destinations is a common part of daily life. To examine the neural basis of these behaviors, we recorded single-neuron activity from neurosurgical patients playing Treasure Hunt, a virtual-reality spatial-memory task. By analyzing how the activity of these neurons related to behavior in Treasure Hunt, we found that the firing rates of many MTL neurons during navigation significantly changed depending on the position of the current spatial target. In addition, we observed neurons whose firing rates during navigation were tuned to specific heading directions in the environment, and others whose activity changed depending on the timing within the trial. By showing that neurons in our task represent remote locations rather than the subject's own position, our results suggest that the human MTL can represent remote spatial information according to task demands.

6.
World Neurosurg ; 133: e842-e849, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31562965

RESUMO

BACKGROUND: Modern science and healthcare generate vast amounts of data, and, coupled with the increasingly inexpensive and accessible computing, a tremendous opportunity exists to use these data to improve care. A better understanding of data science and its relationship to neurosurgical practice will be increasingly important as we transition into this modern "big data" era. METHODS: A review of the literature was performed for key articles referencing big data for neurosurgical care or related topics. RESULTS: In the present report, we first defined the nature and scope of data science from a technical perspective. We then discussed its relationship to the modern neurosurgical practice, highlighting key references, which might form a useful introductory reading list. CONCLUSIONS: Numerous challenges exist going forward; however, organized neurosurgery has an important role in fostering and facilitating these efforts to merge data science with neurosurgical practice.


Assuntos
Big Data , Neurocirurgia , Procedimentos Neurocirúrgicos , Humanos , Neurocirurgiões
7.
Neuroscience ; 425: 194-216, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31786346

RESUMO

High gamma activity (HGA) of verbal-memory encoding using invasive-electroencephalogram has laid the foundation for numerous studies testing the integrity of memory in diseased populations. Yet, the functional connectivity characteristics of networks subserving these memory linkages remains uncertain. By integrating this electrophysiological biomarker of memory encoding from IEEG with resting-state BOLD fluctuations, we estimated the segregation and hubness of HGA-memory regions in drug-resistant epilepsy patients and matched healthy controls. HGA-memory regions express distinctly different hubness compared to neighboring regions in health and in epilepsy, and this hubness was more relevant than segregation in predicting verbal memory encoding. The HGA-memory network comprised regions from both the cognitive control and primary processing networks, validating that effective verbal-memory encoding requires integrating brain functions, and is not dominated by a central cognitive core. Our results demonstrate a tonic intrinsic set of functional connectivity, which provides the necessary conditions for effective, phasic, task-dependent memory encoding.

8.
Cureus ; 11(10): e5900, 2019 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-31763102

RESUMO

Introduction Interprofessional collaboration (IPC) increases patient safety. IPC is learned through task-based exercises, such as ultrasound (U/S)-guided arterial lines. We set out to teach U/S-guided arterial lines as a framework to improve IPC between emergency medicine and neurosurgery residents. The objectives of the study were to provide a U/S session to teach the proper arterial line placement technique, to assess post-workshop arterial line placement competency and attitude toward U/S for procedural guidance, and to improve interdepartmental relationships through IPC. Methods The course was completed in 2018 and consisted of pre-workshop assignments, the workshop, a competency assessment, and a post-workshop survey for neurosurgical residents. After a didactic and hands-on training session, trainees completed a simulated U/S-guided arterial line placement. Trainees then completed a post-workshop assessment. Results There were a total of 21 participants out of 24 total residents, an 87.5% participation rate. Prior to the workshop, on a 5-point Likert scale, where 1 is not at all likely and 5 is very likely, the residents reported they would use U/S 1.7/5, with 57% of respondents answering 1 out of 5. After the workshop, on the same Likert scale, the residents reported using U/S first 3.6/5 (P < 0.05) with 52% of the respondents answering 4 out of 5. After the course, the belief that the landmark technique is non-inferior decreased to 28.6% of respondents. Conclusions The overall goal of this workshop was to improve patient care through continuing education. Using IPC as the framework, the workshop significantly increased the reported likelihood of using U/S for arterial line placement.

9.
Nat Neurosci ; 22(12): 2078-2086, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31712776

RESUMO

The medial temporal lobe is critical for both spatial navigation and memory. Although single neurons in the medial temporal lobe activate to represent locations in the environment during navigation, how this spatial tuning relates to memory for events involving those locations remains unclear. We examined memory-related changes in spatial tuning by recording single-neuron activity from neurosurgical patients performing a virtual-reality object-location memory task. We identified 'memory-trace cells' with activity that was spatially tuned to the retrieved location of the specific object that participants were cued to remember. Memory-trace cells in the entorhinal cortex, in particular, encoded discriminable representations of different memories through a memory-specific rate code. These findings indicate that single neurons in the human entorhinal cortex change their spatial tuning to target relevant memories for retrieval.


Assuntos
Córtex Entorrinal/fisiologia , Rememoração Mental/fisiologia , Neurônios/fisiologia , Percepção Espacial/fisiologia , Atenção/fisiologia , Humanos , Memória/fisiologia , Estimulação Luminosa , Células de Lugar/fisiologia
10.
World Neurosurg ; 131: 264-274.e3, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31369885

RESUMO

In the United States, chronic low back pain affects up to 37% of adults and is a multibillion dollar health care expenditure. Spinal cord simulation (SCS) has been established as an effective treatment alternative for chronic neuropathic low back and leg pain, especially for patients with failed back surgery syndrome or chronic regional pain syndrome. The field of SCS has rapidly advanced such that analgesia can now be achieved through numerous different waveforms, each claiming to offer improved outcomes. These waveforms include traditional paresthesia-based SCS (<100 Hz), paresthesia-free high-frequency SCS (5-10 kHz), burst SCS, and subperception SCS (1-5 kHz). Level 1 evidence critically evaluating the efficacy of these different waveforms is lacking. We conducted a systematic review of the literature in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to identify all randomized controlled trials of SCS in the treatment of chronic neuropathic low back and leg pain, failed back surgery syndrome, or chronic regional pain syndrome. Of 38 eligible studies reviewed, 13 randomized controlled trials were finally included in our systematic review. We reviewed evidence from randomized controlled trials in the field of SCS that have established paresthesia-based SCS, paresthesia-free high-frequency SCS, burst SCS, and subperception SCS as viable treatment options for chronic neuropathic low back and leg pain. We critically evaluated evidence that claims to support the use of one waveform over another and reviewed the literature on patient preference for different waveforms.


Assuntos
Síndromes da Dor Regional Complexa/terapia , Síndrome Pós-Laminectomia/terapia , Dor Lombar/terapia , Estimulação da Medula Espinal/métodos , Dor Crônica/terapia , Humanos , Perna (Membro) , Preferência do Paciente , Ensaios Clínicos Controlados Aleatórios como Assunto , Resultado do Tratamento
12.
Neurosurgery ; 66(Suppl 1): 1-12, 2019 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-31428759
13.
Neurosurgery ; 66(Suppl 1): N3, 2019 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-31428764
14.
Epilepsia ; 60(9): 1949-1959, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31392717

RESUMO

OBJECTIVE: Laser interstitial thermal therapy (LITT) is a novel minimally invasive alternative to open mesial temporal resection in drug-resistant mesial temporal lobe epilepsy (MTLE). The safety and efficacy of the procedure are dependent on the preplanned trajectory and the extent of the planned ablation achieved. Ablation of the mesial hippocampal head has been suggested to be an independent predictor of seizure freedom, whereas sparing of collateral structures is thought to result in improved neuropsychological outcomes. We aim to validate an automated trajectory planning platform against manually planned trajectories to objectively standardize the process. METHODS: Using the EpiNav platform, we compare automated trajectory planning parameters derived from expert opinion and machine learning to undertake a multicenter validation against manually planned and implemented trajectories in 95 patients with MTLE. We estimate ablation volumes of regions of interest and quantify the size of the avascular corridor through the use of a risk score as a marker of safety. We also undertake blinded external expert feasibility and preference ratings. RESULTS: Automated trajectory planning employs complex algorithms to maximize ablation of the mesial hippocampal head and amygdala, while sparing the parahippocampal gyrus. Automated trajectories resulted in significantly lower calculated risk scores and greater amygdala ablation percentage, whereas overall hippocampal ablation percentage did not differ significantly. In addition, estimated damage to collateral structures was reduced. Blinded external expert raters were significantly more likely to prefer automated to manually planned trajectories. SIGNIFICANCE: Retrospective studies of automated trajectory planning show much promise in improving safety parameters and ablation volumes during LITT for MTLE. Multicenter validation provides evidence that the algorithm is robust, and blinded external expert ratings indicate that the trajectories are clinically feasible. Prospective validation studies are now required to determine if automated trajectories translate into improved seizure freedom rates and reduced neuropsychological deficits.

15.
Neuromodulation ; 2019 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-31215711

RESUMO

BACKGROUND: The use of implantable pulse generators (IPG) for spinal cord stimulation (SCS) in patients with chronic pain has been well established. Although IPG-related complications have been reported on, the association between IPG site and SCS complications has not been well studied. OBJECTIVE: To investigate whether IPG placement site in buttock or flank is associated with SCS complications and, hence, revision surgeries. METHOD: A retrospective cohort study was performed that included 330 patients (52% female) treated at a single institution who underwent permanent implantation of an SCS system between 2014 and 2018. Patients ranged between 20 and 94 years of age (mean: 57.54 ± 13.25). Statistical analyses were conducted using IBM SPSS Statistics. Tests included independent samples t test, chi-square test, Mann-Whitney U test, Spearman's rank correlation coefficient, and logistic regression. RESULTS: There was a total of 93 revision surgeries (rate of 28%), where 71 out of 330 patients (rate of 21.5%) had had at least one revision surgery. Univariate tests demonstrated a significant association between IPG site and revision surgeries (p = 0.028 [chi-square test] and p = 0.031 [Mann-Whitney U test]); however, multivariate logistic regression demonstrated that neither IPG site was more likely than the other to require revision surgeries (p = 0.286). CONCLUSION: Although this study found a significant association between IPG site and revision surgeries, the effect of IPG site was not found to be predictive. The IPG site likely influences whether a patient will require revision surgery, but further investigation is required to establish this association.

16.
Neurourol Urodyn ; 38(6): 1669-1675, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31107559

RESUMO

INTRODUCTION: Commercially approved implantable systems for sacral neuromodulation require the implantation of a multipolar lead subcutaneously connected to an implantable pulse generator (IPG). Eliminating the need for an IPG would eliminate the need for tunneling of the lead, reduce procedure time, infection risk, and the need for IPG replacement. The objective was to demonstrate the feasibility of implanting the AHLeveeS System in the S3 Foramen to stimulate the S3 sacral nerve. MATERIALS AND METHODS: A first-in-human, prospective, single center, nonrandomized, acute feasibility clinical investigation at the Maastricht University Medical Center+. Patients with refractory overactive bladder underwent acute implantation of the AHLeveeS neurostimulator before the InterStim procedure. Outcome measurements included motor responses, procedural time and a scoring of the difficulty of the implant and explant procedure. Retrospectively, qualitative responses to the stimulation protocol were assessed by video motion analyses. Only descriptive statistics were used. RESULTS: During the stimulation a motor response to stimulation was seen in four of the five subjects. In all implantations the AHLeveeS was correctly placed. The median time for complete procedure was 24 minutes. The implant and explant procedures were successfully performed and no device or procedure related adverse events occurred. CONCLUSIONS: The results from this acute first-in-human study demonstrate the feasibility of implantation and acute stimulation of the sacral nerve with this mid-field powered system. Future clinical studies will focus on safety and efficacy of a chronically implanted device.

17.
Epilepsia ; 60(6): 1171-1183, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31112302

RESUMO

OBJECTIVE: Laser interstitial thermal therapy (LITT) for mesial temporal lobe epilepsy (mTLE) has reported seizure freedom rates between 36% and 78% with at least 1 year of follow-up. Unfortunately, the lack of robust methods capable of incorporating the inherent variability of patient anatomy, the variability of the ablated volumes, and clinical outcomes have limited three-dimensional quantitative analysis of surgical targeting and its impact on seizure outcomes. We therefore aimed to leverage a novel image-based methodology for normalizing surgical therapies across a large multicenter cohort to quantify the effects of surgical targeting on seizure outcomes in LITT for mTLE. METHODS: This multicenter, retrospective cohort study included 234 patients from 11 centers who underwent LITT for mTLE. To investigate therapy location, all ablation cavities were manually traced on postoperative magnetic resonance imaging (MRI), which were subsequently nonlinearly normalized to a common atlas space. The association of clinical variables and ablation location to seizure outcome was calculated using multivariate regression and Bayesian models, respectively. RESULTS: Ablations including more anterior, medial, and inferior temporal lobe structures, which involved greater amygdalar volume, were more likely to be associated with Engel class I outcomes. At both 1 and 2 years after LITT, 58.0% achieved Engel I outcomes. A history of bilateral tonic-clonic seizures decreased chances of Engel I outcome. Radiographic hippocampal sclerosis was not associated with seizure outcome. SIGNIFICANCE: LITT is a viable treatment for mTLE in patients who have been properly evaluated at a comprehensive epilepsy center. Consideration of surgical factors is imperative to the complete assessment of LITT. Based on our model, ablations must prioritize the amygdala and also include the hippocampal head, parahippocampal gyrus, and rhinal cortices to maximize chances of seizure freedom. Extending the ablation posteriorly has diminishing returns. Further work is necessary to refine this analysis and define the minimal zone of ablation necessary for seizure control.

18.
Brain Res ; 1718: 231-241, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31034813

RESUMO

BACKGROUND: The sphenopalatine ganglion (SPG) is a vasoactive mediator of the anterior intracranial circulation in mammals. SPG stimulation has been demonstrated to alter blood-brain barrier (BBB) permeability, although this phenomenon is not well characterized. OBJECTIVE: To determine the effect of SPG stimulation on the BBB using rat models. METHODS: Extravasation of fluorescent tracer 70 kDa FITC-dextran into rat brain specimens was measured across a range of stimulation parameters to assess BBB permeability. Tight junction (TJ) morphology was compared by assessing differences in the staining of proteins occludin and ZO-1 and analyzing ultrastructural changes on transmission electron microscopy (TEM) between stimulated and unstimulated specimens. RESULTS: SPG stimulation at 10 Hz maximally increased BBB permeability, exhibiting a 6-fold increase in fluorescent traceruptake (1.66% vs 0.28%, p < 0.0001). This effect was reversed 4-hours after stimulation (0.36% uptake, p = 0.99). High-frequency stimulation at 20 Hz and 200 Hz did not increase tracer extravasation, (0.26% and 0.28% uptake, p = >0.999 and p = 0.998, respectively). Stimulation was associated a significant decrease in the colocalization of occludin and ZO-1 with endothelial markers in stimulated brains compared to control (74.6% vs. 39.7% and 67.2% vs. 60.4% colocalization, respectively, p < 0.0001), and ultrastructural changes in TJ morphology associated with increased BBB permeability were observed on TEM. CONCLUSION: This study is the first to show a reversible, frequency-dependent increase in BBB permeability with SPG stimulation and introduces a putative mechanism of action through TJ disruption. Bypassing the BBB with SPG stimulation could enable new paradigms in delivering therapeutics to the CNS. Further study of this technology is needed.

19.
JAMA Neurol ; 76(6): 690-700, 2019 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-30855662

RESUMO

Importance: A functional area associated with the piriform cortex, termed area tempestas, has been implicated in animal studies as having a crucial role in modulating seizures, but similar evidence is limited in humans. Objective: To assess whether removal of the piriform cortex is associated with postoperative seizure freedom in patients with temporal lobe epilepsy (TLE) as a proof-of-concept for the relevance of this area in human TLE. Design, Setting, and Participants: This cohort study used voxel-based morphometry and volumetry to assess differences in structural magnetic resonance imaging (MRI) scans in consecutive patients with TLE who underwent epilepsy surgery in a single center from January 1, 2005, through December 31, 2013. Participants underwent presurgical and postsurgical structural MRI and had at least 2 years of postoperative follow-up (median, 5 years; range, 2-11 years). Patients with MRI of insufficient quality were excluded. Findings were validated in 2 independent cohorts from tertiary epilepsy surgery centers. Study follow-up was completed on September 23, 2016, and data were analyzed from September 24, 2016, through April 24, 2018. Exposures: Standard anterior temporal lobe resection. Main Outcomes and Measures: Long-term postoperative seizure freedom. Results: In total, 107 patients with unilateral TLE (left-sided in 68; 63.6% women; median age, 37 years [interquartile range {IQR}, 30-45 years]) were included in the derivation cohort. Reduced postsurgical gray matter volumes were found in the ipsilateral piriform cortex in the postoperative seizure-free group (n = 46) compared with the non-seizure-free group (n = 61). A larger proportion of the piriform cortex was resected in the seizure-free compared with the non-seizure-free groups (median, 83% [IQR, 64%-91%] vs 52% [IQR, 32%-70%]; P < .001). The results were seen in left- and right-sided TLE and after adjusting for clinical variables, presurgical gray matter alterations, presurgical hippocampal volumes, and the proportion of white matter tract disconnection. Findings were externally validated in 2 independent cohorts (31 patients; left-sided TLE in 14; 54.8% women; median age, 41 years [IQR, 31-46 years]). The resected proportion of the piriform cortex was individually associated with seizure outcome after surgery (derivation cohort area under the curve, 0.80 [P < .001]; external validation cohorts area under the curve, 0.89 [P < .001]). Removal of at least half of the piriform cortex increased the odds of becoming seizure free by a factor of 16 (95% CI, 5-47; P < .001). Other mesiotemporal structures (ie, hippocampus, amygdala, and entorhinal cortex) and the overall resection volume were not associated with outcomes. Conclusions and Relevance: These results support the importance of resecting the piriform cortex in neurosurgical treatment of TLE and suggest that this area has a key role in seizure generation.

20.
Neurosurg Clin N Am ; 30(2): 231-242, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30898274

RESUMO

There are a significant number of patients with epilepsy who are drug-resistant and for whom resective procedures are not an option. For these patients, neuromodulation may be an option, including closed-loop stimulation, such as responsive neurostimulation (RNS). The RNS System is a programmable and responsive device that consists of leads, a pulse generator, and an external programmer. An algorithm detects specific patterns of epileptogenic activity and triggers focal stimulation to interrupt a seizure. RNS is an effective and safe adjunctive therapy that in addition to seizure frequency reduction may have other applications, such as drug-response evaluation and long-term electrocorticography recording.


Assuntos
Estimulação Encefálica Profunda/métodos , Epilepsia/terapia , Convulsões/terapia , Humanos , Resultado do Tratamento
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA