165 research outputs found
Assessing a 600-mg Loading Dose of Clopidogrel 24 Hours Prior to Pipeline Embolization Device Treatment
Background:
Clopidogrel/aspirin antiplatelet therapy routinely is administered 7-10 days before pipeline aneurysm treatment. Our study assessed the safety and efficacy of a 600-mg loading dose of clopidogrel 24 hours before Pipeline Embolization Device (PED) treatment.
Methods: In this retrospective cohort study, we included patients treated with PED from October 2010 to May 2016. A total of 39.7% (n = 158) of patients were dispensed a loading dose of 650 mg of aspirin plus at least 600 mg of clopidogrel 24 hours preceding PED deployment, compared to 60.3% (n = 240) of patients who received 81-325 mg of aspirin daily for 10 days with 75 mg of clopidogrel daily preprocedurally. The mean follow-up was 15.8 months (standard deviation [SD] 12.4 months). modified Rankin Scale (mRS) was registered before the discharge and at each follow-up visit. To control confounding, we used multivariable logistic regression and propensity score conditioning.
Results: Of 398 patients, the proportion of female patients was ~16.5% (41/240) in both groups and shared the same mean of age ~56.46 years. ~12.2% (mean = 0.09; SD = 0.30) had a subarachnoid hemorrhage. 92% (mean = 0.29; SD = 0.70) from the pretreatment group and 85.7% (mean = 0.44; SD = 0.91) of the bolus group had a mRS ≤2. In multivariate analysis, bolus did not affect the mRS score, P = 0.24. Seven patients had a long-term recurrence, 2 (0.83%; mean = 0.01; SD = 0.10) of which from the pretreatment group. In a multivariable logistic regression, bolus was not associated with a long-term recurrence rate (odds ratio [OR] 1.91; 95% confidence interval [CI] 0.27-13.50; P = 0.52) or with thromboembolic accidents (OR 0.99; 95% CI 0.96-1.03; P = 0.83) nor with hemorrhagic events (OR 1.00; 95% CI 0.97-1.03; P = 0.99). Three patients died: one who received a bolus had an acute subarachnoid hemorrhage. The mean mortality rate was parallel in both groups ~0.25 (SD = 0.16). Bolus was not associated with mortality (OR 1.11; 95% CI 0.26-4.65; P = 0.89). The same associations were present in propensity score-adjusted models.
Conclusions: In a cohort receiving PED, a 600-mg loading dose of clopidogrel should be safe and efficacious in those off the standard protocol or showing \u3c30% platelet inhibition before treatment
The Use of Prasugrel and Ticagrelor in Pipeline Flow Diversion
Background:
Despite the routine clopidogrel/aspirin anti-platelet therapy, complications like thromboembolism, continue to be encountered with PED. We studied the safety and the efficacy of prasugrel in the management of clopidogrel non-responders treated for intracranial aneurysms.
Methods:
437 consecutive neurosurgery patients were identified between January 2011 and May 2016. Patients allergic or having \u3c30% platelet-inhibition with a daily 75mg of clopidogrel were dispensed 10mg of prasugrel daily (n=20) or 90mg of ticagrelor twice daily (n=2). The average follow-up was 15.8 months (SD=12.4 months). Patient clinical well being was evaluated with the modified Rankin Scale (mRS) registered before the discharge and at each follow-up visit. To control confounding we used multivariable mixed-effects logistic regression and propensity score conditioning.
Results:
26 of 437(5.9%) patients (mean of age 56.3 years; 62 women [14,2%]) presented with a sub-arachnoid hemorrhage. 1 patient was allergic to clopidogrel and prasugrel simultaneously. All the patients receiving prasugrel (n=22) had a mRS\u3c2 on their latest follow-up visit (mean=0.67; SD=1.15). In a multivariate analysis, clopidogrel did not affect the mRS on last follow-up, p=0.14. Multivariable logistic regression showed that clopidogrel was not associated with an increased long-term recurrence rate (odds ratio[OR], 0.17; 95%Confidence Interval [CI95%], 0.01-2.70; p=0.21) neither with an increased thromboembolic accident rate (OR, 0.46; CI95%, 0.12-1.67; p=0.36) nor with an increased hemorrhagic event rate (OR, 0.39; CI95%,0.91-1.64; p=0.20). None of the patients receiving prasugrel deceased or had a long-term recurrence nor a hemorrhagic event, only 1 patient suffered from mild aphasia subsequent to a thromboembolic event. 3 patients on clopidogrel passed during the study: (2) from acute SAH and (1) from intra-parenchymal hemorrhage. Clopidogrel was not associated with an increased mortality rate (OR, 2.18; CI95%,0.11-43.27; p=0.61). The same associations were present in propensity score adjusted models.
Conclusion:
In a cohort of patients treated with PED for their intracranial aneurysms, prasugrel (10mg/day) is a safe alternative to clopidogrel resistant, allergic or non-responders
Transmission des voies olfactives aux cellules réticulospinales de la lamproie
Les informations olfactives sont connues pour leur capacité à induire des comportements moteurs spécifiques. En dépit de nombreuses observations comportementales chez les vertébrés, on ne connaît toujours pas les mécanismes et les voies nerveuses qui sous-tendent ces phénomènes de transformation olfacto-locomotrices. Chez la lamproie, des travaux récents ont permis de décrire cette voie, et les mécanismes responsables de la transformation des entrées olfactives en activité locomotrice (Derjean et al., 2010). Cette voie prend origine dans la partie médiane du bulbe olfactif, et envoie des projections vers le tubercule postérieur, une région qui se trouve dans le diencéphale. De là, les neurones projettent directement vers la Région Locomotrice Mésencéphalique, connue pour envoyer des connexions vers les neurones réticulospinaux, et activer la locomotion.
L’objectif de cette étude était d’établir si l’ensemble des neurones réticulospinaux répond aux stimulations olfactives. Pour ce faire, nous avons utilisé sur une préparation de cerveau isolé de lamproie des techniques d’électrophysiologie et d’imagerie calcique.
La stimulation électrique des nerfs olfactifs, de la région médiane du bulbe olfactif ou du tubercule postérieur a provoqué une activation de toutes les cellules réticulospinales qui se retrouvent dans les quatre noyaux réticulaires (ARRN : Noyau Réticulaire Rhombencéphalique Antérieur; MRN : Noyau Réticulaire Mésencéphalique; MRRN : Noyau Réticulaire Rhombencéphalique Moyen; PRRN : Noyau Réticulaire Rhombencéphalique Postérieur). Seule la partie médiane du bulbe olfactif est impliquée dans le passage de l’information olfactive vers les neurones réticulospinaux. Nous avons aussi découvert que le blocage des récepteurs GABAergiques dans la partie médiane du bulbe olfactif augmentait les réponses olfactives de façon considérable dans les cellules réticulospinales. Nous avons montré ainsi qu’il existe un tonus inhibiteur impliqué dans la dépression modulatrice de la voie olfacto-locomotrice.
Ce travail a permis de montrer que la stimulation des afférences sensorielles olfactives active simultanément l’ensemble des populations de neurones réticulospinaux qui commandent la locomotion. De plus, il existerait un tonus inhibiteur GABAergique, au niveau de la partie médiane du bulbe olfactif, responsable d’une dépression modulatrice dans la voie olfacto-locomotrice.Olfactory inputs are known for their ability to induce specific motor behaviors. Despite numerous behavioral observations in vertebrates, the mechanisms and the neural pathways underlying the olfactory-locomotor transformation are still unknown. In lamprey, recent studies have described this pathway and the mechanism underlying the transformation of olfactory input into a locomotor activity (Derjean et al., 2010). This pathway originates in the medial part of the olfactory bulb, sends projections to the posterior tuberculum, a diencephalic region. From there, the neurons project directly to the mesencephalic locomotor region that is known to send projections to the reticulospinal neurons to activate locomotion.
Using lamprey brain preparation, electrophysiology and calcium imaging, the aim of this study was to establish whether all reticulospinal neurons respond to olfactory stimuli. Electrical stimulation of the olfactory nerves, the medial part of the olfactory bulb or the posterior tuberculum activates all reticulospinal cells in the four reticular nuclei (ARRN: Anterior rhombencephalic reticular nucleus; MRN: middle mesencephalic reticular nucleus; MRRN: middle rhombencephalic reticular nucleus; PRRN: posterior rhombencephalic reticular nucleus). The medial part of the olfactory bulb is the only region that is implicated in transmitting the olfactory information to reticulospinal neurons. We also discovered that when blocking the GABAergic receptors in the medial part of the olfactory bulb, the reticulospinal neurons have a stronger response to olfactory stimulation. Thus we showed that a tonic inhibition is involved in the modulating depression of the olfacto-locomotor pathway.
Altogether, this work shows that stimulation of the olfactory sensory inputs activates simultaneously the entire population of reticulospinal neurons that control locomotion. In addition, there is a GABAergic tonic inhibition at the level of the medial part of the olfactory bulb that causes a modulating depression in the olfacto-locomotor pathway
Endoscopic Transventricular Inside-Out Corpus Callosotomy: Illustrative Case
BACKGROUND: Tonic and atonic drop attack seizures are a classic and morbid semiology in Lennox-Gastaut syndrome, resulting in frequent injuries and emergency room visits, in addition to neurocognitive sequelae. Recent years have seen a growing interest in less invasive techniques for performing the classic surgical treatment for drop attacks in Lennox-Gastaut syndrome, that is, corpus callosotomy.
OBSERVATIONS: A 5-year-old boy with Lennox-Gastaut syndrome presented for surgical evaluation. He experienced up to 20 daily tonic seizures despite multiple antiseizure medications. Preoperative imaging revealed highly abnormal anatomy with severe ventriculomegaly and thinning of the cortex and corpus callosum. Open microsurgery or an interhemispheric bimanual endoscopic approach to corpus callosotomy posed a risk for ventricular collapse and subdural hematoma, and the corpus callosum was too thin for laser ablation. A fully endoscopic transventricular inside-out complete corpus callosotomy was performed through a 7-mm burr hole via a single working channel without intraoperative complications. The patient continues to experience daily seizures but with a reduced frequency and intensity and a family-reported increased quality of life.
LESSONS: In cases of drug-resistant tonic and atonic seizures associated with ventriculomegaly, a fully endoscopic transventricular complete corpus callosotomy can be performed safely, potentially limiting the risk of ventricular collapse and subdural bleeding. https://thejns.org/doi/10.3171/CASE24160
Rare Case of Diffuse Spinal Arachnoiditis Following a Complicated Vertebral Artery Dissection
Spinal arachnoiditis (SA) is an extremely rare and delayed complication of intracranial subarachnoid hemorrhage (SAH). SA is an inflammatory process leading to chronic fibrosis of the spinal cord. Possible pathophysiology is a two-staged disease of initial inflammatory reaction secondary to SAH, followed by a “free interval phase” prior to delayed adhesive phase (i.e. SA). The clinical course can be complicated and is the cause of major morbidity.https://jdc.jefferson.edu/neurosurgeryposters/1009/thumbnail.jp
Gastric Perforation From a Migrating Ventriculoperitoneal Shunt: A Case Report and Review of Literature
Ventriculoperitoneal (VP) shunts represent a surgical option for patients affected by increased intracranial hypertension when medical management fails or is contraindicated. Complications following implantation include shunt obstruction, infection, over and under drainage, migration or disconnection of the tube, formation of a pseudocyst, and allergy to the silicone tube. We report the case of a 31-year-old woman who presented to the emergency room with nausea and generalized malaise, found to have the distal segment of the VP catheter perforating her gastric wall into the stomach lumen which required surgical intervention. In this report, we describe a rare complication associated with the implantation of ventriculoperitoneal shunt (VPS) catheters and the subsequent management plan
Multi-messenger observations of a binary neutron star merger
On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta
Multifocal electroretinography in amblyopia
Purpose: To identify whether there are functional abnormalities in the retina of amblyopic eyes using multifocal electroretinography (mfERG). Methods: This is a prospective study of patients ≥ 7 years of age identified with unilateral amblyopia (strabismic or anisometropic). Multifocal ERG and flash ERG were performed to compare parameters between the amblyopic and non-amblyopic fellow eyes. A complete analysis of the five ring averages was done including the central ring. Results: Thirty-eight patients were included: mean age was 14.3 ± 7.3 years; 18 patients were strabismic and 20 were anisometropic. Amblyopic eye responses across the rings in multifocal ERG were diminished compared with fellow non-amblyopic eyes with significant differences detected in the central rings (p = 0.001). On the other hand, flash ERG did not show any consistently significant differences. When divided by severity, amplitudes of central rings were significantly lower in severely amblyopic eyes compared with non-amblyopic eyes (p = 0.001), while in mild amblyopia, no significant differences were observed. No significant difference was observed between anisometropic and strabismic amblyopic eyes. Conclusions: Using multifocal ERG, significantly decreased amplitudes were observed in amblyopic eyes compared with normal fellow eyes in the central ring. This correlated with the severity of amblyopia. No difference was observed when comparing the two groups of amblyopia (strabismic and anisometropic). Those findings may help clarify the pathophysiology of amblyopia better and open the door for new objective ways to monitor the response to amblyopia treatment but this needs to be further studied. © 2020, Springer-Verlag GmbH Germany, part of Springer Nature
Long-Term Outcomes Following Posterior Fossa Decompression in Pediatric Patients with Chiari Malformation Type 1, a Population-Based Cohort Study
OBJECTIVE: Posterior fossa decompression for Chiari malformation type I (Chiari 1) is effective and associated with a low risk of complication. However, up to 20% of patients may experience continued deficits or recurring symptoms after surgical intervention. For pediatric patients, there are no established tools to predict outcomes, and the risk factors for unfavorable postoperative outcomes are poorly understood. Hence, our aim was to investigate baseline data and early postoperative predictors of poor outcomes as determined by the Chicago Chiari outcome scale (CCOS).
METHODS: All pediatric patients (\u3c 18 years) receiving a posterior fossa decompression for Chiari 1 between the years of 2005 and 2020 at the study center were eligible for inclusion. Patients with congenital anomalies were excluded.
RESULTS: Seventy-one pediatric patients with a median age of 9 years were included. Most patients (58%) were females. Chiari 1 was associated with syringomyelia (51%), scoliosis (37%), and hydrocephalus (7%). Perioperative complications occurred in 13 patients (18%) of which two required additional procedures under general anesthesia. On multivariable proportional odds logistic regression, motor deficits (OR: 0.09; CI95%: [0.01-0.62]; p = 0.015), and surgical complications (OR: 0.16; CI95%: [0.41-0.66]; p = 0.011) were significant predictors of worse outcomes. The presence of syringomyelia was identified as a predictor of better outcomes (OR: 4.42 CI95% [1.02-19.35]; p = 0.048). A persistent hydrocephalus during the early postoperative period after posterior fossa decompression was a strong predictor of worse long-term CCOS (OR: 0.026; CI95%: [0.002-0.328]; p = 0.005).
CONCLUSION: Results from this study indicate that the existence of motor deficits and syringomyelia prior to surgery, and surgical complications and persistent hydrocephalus despite posterior fossa decompression, were useful predictors of long-term outcome
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