Journal of neurosurgery
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Journal of neurosurgery · Oct 2019
Case ReportsModulation of neural oscillations by vagus nerve stimulation in posttraumatic multifocal epilepsy: case report.
The putative mechanism of vagus nerve stimulation (VNS) for medically refractory epilepsy is desynchronization of hippocampal and thalamocortical circuitry; however, the nature of the dose-response relationship and temporal dynamics is poorly understood. For greater elucidation, a study in a nonepileptic rat model was previously conducted and showed that rapid-cycle (RC) VNS achieved superior desynchrony compared to standard-cycle (SC) VNS. Here, the authors report on the first in-human analysis of the neuromodulatory dose-response effects of VNS in a patient with posttraumatic, independent, bilateral mesial temporal lobe epilepsy refractory to medications and SC-VNS who was referred as a potential candidate for a responsive neurostimulation device. ⋯ Spectral analysis revealed a global reduction of power in the theta (4-8 Hz) and alpha (8-15 Hz) bands with both SC- and RC-VNS compared to the stimulation off setting (p < 0.001). Furthermore, in the alpha band, both SC- and RC-VNS were associated with greater global desynchrony compared to the off setting (p < 0.001); and, specifically, in the bilateral epileptogenic hippocampi, RC-VNS further reduced spectral power compared to SC-VNS (p < 0.001). The dose-response and temporal effects suggest that VNS modulates regional and global dynamics differently.
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Journal of neurosurgery · Oct 2019
Case ReportsIntracranial hypertension after Chiari decompression resolving after removal of a levonorgestrel-releasing intrauterine device: case report.
Levonorgestrel-releasing intrauterine devices (LIUDs) are thought to release this progestin locally in the uterus to limit side effects. Authors here present a case of treatment-refractory hydrocephalus and pseudomeningocele (PMC), both of which fully resolved after LIUD removal. A 35-year-old woman with an implanted LIUD developed symptomatic PMC and hydrocephalus after suboccipital craniectomy for Chiari malformation type I. ⋯ This case indicates that a persistent problem (PMC and intracranial hypertension) that may be associated with the LIUD rapidly resolves after its removal. Implication of LIUDs as the cause of intracranial hypertension is still a matter of controversy. Further studies are needed to evaluate any potential causal relationship between LIUDs and intracranial hypertension, and physicians are advised to consider this scenario in their differential diagnosis.
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Journal of neurosurgery · Oct 2019
Nationwide analysis of hospital-to-hospital transfer in patients with aneurysmal subarachnoid hemorrhage requiring aneurysm repair.
Aneurysmal subarachnoid hemorrhage (aSAH) has devastating consequences. The association between higher institutional volumes and improved outcomes for aSAH patients has been studied extensively. However, the literature exploring patterns of transfer in this context is sparse. Expansion of the endovascular workforce has raised concerns about the decentralization of care, reduced institutional volumes, and worsened patient outcomes. In this paper, the authors explored various patient and hospital factors associated with the transfer of aSAH patients by using a nationally representative database. ⋯ A relatively high percentage of patients with aSAH are transferred between acute care hospitals. Race and income were associated with transfer status. White patients are more likely to be transferred than other races. Patients from zip codes with the highest income transferred at lower rates than those from the lowest income quartile. Transfer patients were preferentially sent to urban teaching hospitals. The modality of aneurysm treatment was not associated with transfer status.
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Journal of neurosurgery · Oct 2019
Endoscopic transorbital surgery for Meckel's cave and middle cranial fossa tumors: surgical technique and early results.
Tumors involving Meckel's cave remain extremely challenging because of the surrounding complex neurovascular structures and deep-seated location. The authors investigated a new minimal-access technique using the endoscopic transorbital approach (eTOA) through the superior eyelid crease to Meckel's cave and middle cranial fossa lesions and reviewed the most useful surgical procedures and pitfalls of this approach. ⋯ The eTOA affords a direct route to access Meckel's cave and middle cranial fossa lesions. With experience, this novel approach can be successfully applied to selected skull base lesions. To achieve successful removal of the tumor, emphasis should be placed on the importance of adequately removing the greater sphenoid wing and vertical crest. However, because of limited working space eTOA may not be an ideal approach for posterior fossa lesions.
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Journal of neurosurgery · Oct 2019
Validation of corpus callosotomy after laser interstitial thermal therapy: a multimodal approach.
Disconnection of the cerebral hemispheres by corpus callosotomy (CC) is an established means to palliate refractory generalized epilepsy. Laser interstitial thermal therapy (LITT) is gaining acceptance as a minimally invasive approach to treating epilepsy, but this method has not been evaluated in clinical series using established methodologies to assess connectivity. The goal in this study was to demonstrate the safety and feasibility of MRI-guided LITT for CC and to assess disconnection by using electrophysiology- and imaging-based methods. ⋯ MRI-guided LITT provides an effective minimally invasive alternative method for CC in the treatment of seizures associated with drop attacks, bilaterally synchronous onset, and rapid secondary generalization. The disconnection is confirmed using anatomical and functional neuroimaging and electrophysiological measures.