Navigated bedside implantation of external ventricular drains with mobile health guidance: technical note and case series.

PURPOSE: External ventricular drain (EVD) implantation is one of the fundamental procedures of emergency neurosurgery usually performed freehand at bedside or in the operating room using anatomical landmarks. However, this technique is frequently associated with malpositioning leading to complications or dysfunction. Here, we describe a novel navigated bedside EVD insertion technique, which is evaluated in a clinical case series with the aim of safety, accuracy, and efficiency in neurosurgical emergency settings. METHODS: From 2021 to 2022, a mobile health-assisted navigation instrument (Thomale Guide, Christoph Miethke, Potsdam, Germany) was used alongside a battery-powered single-use drill (Phasor Health, Houston, USA) for bedside EVD placement in representative neurosurgical pathologies in emergency situations requiring ventricular cerebrospinal fluid (CSF) relief and intracranial pressure (ICP) monitoring. RESULTS: In all 12 patients (8 female and 4 male), navigated bedside EVDs were placed around the foramen of Monro at the first ventriculostomy attempt. The most frequent indication was aneurysmal subarachnoid hemorrhage. Mean operating time was 25.8 ± 15.0 min. None of the EVDs had to be revised due to malpositioning or dysfunction. Two EVDs were converted into a ventriculoperitoneal shunt. Drainage volume was 41.3 ± 37.1 ml per day in mean. Mean length of stay of an EVD was 6.25 ± 2.8 days. Complications included one postoperative subdural hematoma and cerebrospinal fluid infection, respectively. CONCLUSION: Combining a mobile health-assisted navigation instrument with a battery-powered drill and an appropriate ventricular catheter may enable and enhance safety, accuracy, and efficiency in bedside EVD implantation in various pathologies of emergency neurosurgery without adding relevant efforts.

Lithium inhibits tryptophan catabolism via the inflammation-induced kynurenine pathway in human microglia.

Despite its decades' long therapeutic use in psychiatry, the biological mechanisms underlying lithium's mood-stabilizing effects have remained largely elusive. Here, we investigated the effect of lithium on tryptophan breakdown via the kynurenine pathway using immortalized human microglia cells, primary human microglia isolated from surgical specimens, and microglia-like cells differentiated from human induced pluripotent stem cells. Interferon (IFN)-γ, but not lipopolysaccharide, was able to activate immortalized human microglia, inducing a robust increase in indoleamine-2,3-dioxygenase (IDO1) mRNA transcription, IDO1 protein expression, and activity. Further, chromatin immunoprecipitation verified enriched binding of both STAT1 and STAT3 to the IDO1 promoter. Lithium counteracted these effects, increasing inhibitory GSK3ßS9 phosphorylation and reducing STAT1S727 and STAT3Y705 phosphorylation levels in IFN-γ treated cells. Studies in primary human microglia and hiPSC-derived microglia confirmed the anti-inflammatory effects of lithium, highlighting that IDO activity is reduced by GSK3 inhibitor SB-216763 and STAT inhibitor nifuroxazide via downregulation of P-STAT1S727 and P-STAT3Y705 . Primary human microglia differed from immortalized human microglia and hiPSC derived microglia-like cells in their strong sensitivity to LPS, resulting in robust upregulation of IDO1 and anti-inflammatory cytokine IL-10. While lithium again decreased IDO1 activity in primary cells, it further increased release of IL-10 in response to LPS. Taken together, our study demonstrates that lithium inhibits the inflammatory kynurenine pathway in the microglia compartment of the human brain.

Surgical revision after Vagus Nerve Stimulation. A case series.

With increasing use of vagus nerve stimulation (VNS) as an adjunct treatment for drug-resistant epilepsy, revision surgery of VNS grows in importance. Indications for revision surgery are diverse and extend of surgery varies. We report a retrospective review on indications and complications of VNS revision surgery at our center. Of 90 VNS procedures 54.4% were revision surgeries. Among those the vast majority was due to depletion of the battery. The entire system was explanted in 15 patients, due to no beneficial effect detected (n = 4), due to irritating side effects (n = 4), and so further diagnostics could cbe carried out (n = 7). Interestingly in three of the patients who underwent further diagnostics, resective epilepsy surgery was performed. Surgical complications occurred in 8.2%. In our experience, revision surgery of VNS was a frequent and safe procedure. There is a need to carefully reviewthe initial indication for VNS implantation prior to revision surgery.

High-throughput microcircuit analysis of individual human brains through next-generation multineuron patch-clamp.

Comparing neuronal microcircuits across different brain regions, species and individuals can reveal common and divergent principles of network computation. Simultaneous patch-clamp recordings from multiple neurons offer the highest temporal and subthreshold resolution to analyse local synaptic connectivity. However, its establishment is technically complex and the experimental performance is limited by high failure rates, long experimental times and small sample sizes. We introduce an in vitro multipatch setup with an automated pipette pressure and cleaning system facilitating recordings of up to 10 neurons simultaneously and sequential patching of additional neurons. We present hardware and software solutions that increase the usability, speed and data throughput of multipatch experiments which allowed probing of 150 synaptic connections between 17 neurons in one human cortical slice and screening of over 600 connections in tissue from a single patient. This method will facilitate the systematic analysis of microcircuits and allow unprecedented assessment of inter-individual variability.

Effects of vagus nerve stimulation on symptoms of depression in patients with difficult-to-treat epilepsy.

PURPOSE: Vagus nerve stimulation (VNS) is well established in the treatment of epilepsy and disorders of depression. The prevalence of depression is high in patients with epilepsy, but still it remains unclear how patients with a comorbidity of epilepsy and symptoms of depression respond to VNS. METHODS: We investigated 59 patients with different subtypes of disorders of depression as a comorbidity of epilepsy, who underwent VNS-surgery. Before and one year after VNS surgery, the severity of symptoms of depression was evaluated by a psychiatrist using Montgomery-Åsberg Depression Rating Scale (MADRS) and Beck-Depressions-Inventory (BDI). Response towards epilepsy was measured by a seizure reduction of at least 50%. RESULTS: Symptoms of depression ameliorated in response to VNS in the overall of all patients MADRS 29 to 18 (p < 0,001) and BDI 24 to 14 (p < 0,001) and all subtypes of disorders of depression. Seizure reduction of at least 50% was achieved in two out of three of all patients two years after VNS. CONCLUSION: We were able to show the beneficial effect of VNS in the treatment of patients with pharmacoresistant epilepsy and a comorbidity of symptoms of depression.

[Intrasylvian dermoid cysts of the pediatric patient: a case report and review].

OBJECTIVE: Supratentorial dermoid cysts are unusual benign mass lesions in pediatric patients, especially if located in a lateralized position such as in the lateral sulcus. Since these lesions often adhere tightly to circumjacent nerves or vessels, preoperative evaluation is important. Here we report on a pediatric patient with an intrasylvian dermoid cyst who underwent radical microsurgical resection and review the relevant literature. METHODS: An 8-year-old girl with a cystic space-occupying lesion in the right lateral sulcus was referred to our hospital. The lesion appeared similar to CSF on T1/T2 sequences on magnetic resonance imaging(MRI). However, diffusion-weighted imaging(DWI)indicated high diffusion restriction. During the operation, dermal appendage was found within the tumor capsule. Gross total resection was achieved and the patient was discharged without any deficits. Histological findings confirmed the diagnosis of a dermoid cyst. DISCUSSION: Only three cases of pediatric patients with dermoid cysts located in the lateral sulcus have been described. Due to its rarity and highly variable appearance on MRI, obtaining a differential diagnosis is difficult. Gross total resection should be the surgical goal;nevertheless, adjacent structures must be preserved. CONCLUSION: Here we described an additional rare case of intrasylvian dermoid cyst in childhood. The appearance of such cysts on DWI can aid with their preoperative diagnosis.

Extracranial posterior communicating artery bypass for revascularization of patients with common carotid artery occlusion.

BACKGROUND: Extracranial-intracranial bypass surgery provides blood flow augmentation in patients suffering from intracranial or long-distance conductance artery stenosis or occlusion that otherwise cannot be treated. The standard procedure for these cases is an anastomosis between the superficial temporal and middle cerebral arteries. However, in patients presenting with common carotid artery occlusion, the superficial temporal artery is no longer sufficiently perfused. For these patients, alternative revascularization strategies have to be applied. OBJECTIVE: To describe a novel strategy for revascularization of patients with common carotid artery occlusion, ie, the extracranial posterior communicating artery bypass. METHODS: Two patients with chronic cerebrovascular compromise resulting in transitory ischemic attacks and/or border-zone infarctions caused by common carotid artery occlusion were referred to our institution. A radial artery bypass was established between the third segment of the vertebral artery and an M3 branch of the middle cerebral artery. The vertebral artery was exposed between the vertebral lamina of C1 and occipital bone via a paramedian incision. The bypass was tunneled subcutaneously, conducted intracranially via a tailored extended burr-hole craniotomy, and anastomosed to a recipient M3 vessel. RESULTS: The postoperative course of both patients was uneventful in terms of cerebral ischemia or bleeding complications. In both patients, postoperative angiographic controls revealed an excellent bypass function with markedly improved hemispheric filling of multiple middle cerebral artery branches. The patients were discharged without new neurological symptoms. CONCLUSION: Our extracranial posterior communicating artery bypass using a radial artery transplant from the vertebral artery to the middle cerebral artery is a useful tool to treat patients suffering from hemodynamic cerebrovascular compromise caused by common carotid artery occlusion.