Subthalamic Deep Brain Stimulation under General Anaesthesia for Parkinson's Disease: Institutional Experience and Outcomes.

Introduction: Direct targeting in deep brain stimulation (DBS) has remarkably impacted the patient's experience throughout the surgery and the overall logistics of the procedure. When the individualised plan is co-registered with a 3D image acquired intraoperatively, the electrodes can be safely placed under general anaesthesia. How this applies to a general practice scenery (outside clinical trials and in a moderate caseload centre) has been scarcely reported.

Understanding the Importance of Blood-Brain Barrier Alterations in Brain Arteriovenous Malformations and Implications for Treatment: A Dynamic Contrast-Enhanced-MRI-Based Prospective Study.

Background And Objectives: The major clinical implication of brain arteriovenous malformations (bAVMs) is spontaneous intracranial hemorrhage. There is a growing body of experimental evidence proving that inflammation and blood-brain barrier (BBB) dysfunction are involved in both the clinical course of the disease and the risk of bleeding. However, how bAVM treatment affects perilesional BBB disturbances is yet unclear.

Cerebral autoregulation derived blood pressure targets in elective neurosurgery.

Poor postoperative outcomes may be associated with cerebral ischaemia or hyperaemia, caused by episodes of arterial blood pressure (ABP) being outside the range of cerebral autoregulation (CA). Monitoring CA using COx (correlation between slow changes in mean ABP and regional cerebral O saturation-rSO) could allow to individualise the management of ABP to preserve CA. We aimed to explore a continuous automated assessment of ABP (ABP where CA is best preserved) and ABP at the lower limit of autoregulation (LLA) in elective neurosurgery patients.

MicroRNA cerebrospinal fluid profile during the early brain injury period as a biomarker in subarachnoid hemorrhage patients.

Introduction: Delayed cerebral ischemia (DCI) is a dreadful complication present in up to 30% of patients with spontaneous subarachnoid hemorrhage (SAH). Indeed, DCI is one of the main causes of long-term disability in SAH, yet its prediction and prevention are troublesome in poor-grade SAH cases. In this prospective study, we explored the potential role of micro ribonucleic acid (microRNA, abbreviated miRNAs)-small non-coding RNAs involved in clue gene regulation at the post-transcriptional level-as biomarkers of neurological outcomes in SAH patients.

Minimally Invasive Surgery for Spontaneous Intracerebral Hematoma. Real-Life Implementation Model and Economic Estimation.

Objective: Spontaneous intracerebral hemorrhage is characterized by high fatality outcomes, even under best medical treatment. Recently, minimally invasive surgical (MIS) evacuation of the hematoma has shown promising results and may soon be implemented in the clinical practice. Hereby, we intended to foresee the logistic requirements for an early hematoma evacuation protocol, as well as to evaluate in a real-life implementation model the cost-utility of the two main MIS techniques for hemorrhagic stroke (catheter evacuation plus thrombolysis and neuroendoscopic aspiration).

Venous tortuosity as a novel biomarker of rupture risk in arteriovenous malformations: ARI score.

Background: Risk of rupture in arteriovenous malformations (AVMs) varies considerably among series. Hemodynamic factors, especially within the venous side of the circuit, seem to be responsible but are not yet well defined. We analyzed tortuosity in the draining vein as a potential new marker of rupture in AVMs, and propose a simple index to predict AVM bleeding.

Hemodynamic Response, Coughing and Incidence of Cerebrospinal Fluid Leakage on Awakening with an Endotracheal Tube or Laryngeal Mask Airway in Place after Transsphenoidal Pituitary Surgery: A Randomized Clinical Trial.

We aimed to compare systemic and cerebral hemodynamics and coughing during emergence after pituitary surgery after endotracheal tube (ETT) extubation or after replacing ETT with a laryngeal mask airway (LMA). Patients were randomized to awaken with an ETT in place or after replacing it with an LMA. We recorded mean arterial pressure (MAP), heart rate, middle cerebral artery (MCA) flow velocity, regional cerebral oxygen saturation (SrO), cardiac index, plasma norepinephrine, need for vasoactive drugs, coughing during emergence, and postoperative cerebrospinal fluid (CSF) leakage.

Intraoperative magnetic resonance imaging for cerebral cavernous malformations: When is it maybe worth it?

Objective: Intraoperative magnetic resonance imaging (iMRI) can be useful for cerebral cavernous malformations (CCM) surgery. However, literature on this topic is scarce. We aim to investigate its clinical utility and propose criteria for the selection of patients who may benefit the most from iMRI.

Effects on cerebral blood flow of position changes, hyperoxia, CO2 partial pressure variations and the Valsalva manoeuvre: A study in healthy volunteers.

Background: Maintaining adequate blood pressure to ensure proper cerebral blood flow (CBF) during surgery is challenging. Induced mild hypotension, sitting position or unavoidable intra-operative circumstances such as haemorrhage, added to variations in carbon dioxide and oxygen tensions, may influence perfusion. Several of these circumstances may coincide and it is unclear how these may affect CBF.

Estimation of pulsatile cerebral arterial blood volume based on transcranial doppler signals.

Objective: Mathematical modeling of cerebral hemodynamics by descriptive equations can estimate the underlying pulsatile component of cerebral arterial blood volume (CaBV). This way, clinical monitoring of changes in cerebral compartmental compliances becomes possible. Our aim is to validate the most adequate method of CaBV estimation in neurocritical care.

Association between preoperative serum lactate concentrate with tumor cell proliferative index in primary brain tumor.

Background: Elevated preoperative lactate levels have been reported in patients admitted for resection of brain tumors. As histologic type and tumor grade have also been linked to lactate concentration, we hypothesized that preoperative lactate concentration in patients with brain tumors may be associated with tumor proliferation. We describe the relationship between preoperative plasma lactate levels, and the cell proliferation marker Ki-67 in brain tumor surgery.

Relationship Between Brain Pulsatility and Cerebral Perfusion Pressure: Replicated Validation Using Different Drivers of CPP Change.

Background: Determination of relationships between transcranial Doppler (TCD)-based spectral pulsatility index (sPI) and pulse amplitude (AMP) of intracranial pressure (ICP) in 2 groups of severe traumatic brain injury (TBI) patients (a) displaying plateau waves and (b) with unstable mean arterial pressure (MAP).

Methods: We retrospectively reviewed patients with severe TBI and continuous TCD monitoring displaying either plateau waves or unstable MAP from 1992 to 1998. We utilized linear and nonlinear regression techniques to describe both cohorts: cerebral perfusion pressure (CPP) versus AMP, CPP versus sPI, mean ICP versus ICP AMP, mean ICP versus sPI, and AMP versus sPI.

Experience with "Fast track" postoperative care after deep brain stimulation surgery.

Background: A 24-h-stay in the post-anesthesia care unit (PACU) is a common postoperative procedure after deep brain stimulation surgery (DBS).

Objective: We evaluated the impact of a fast-track (FT) postoperative care protocol.

Methods: An analysis was performed on all patients who underwent DBS in 2 periods: 2006, overnight monitored care (OMC group), and 2007-2013, FT care (FT group).

Laryngeal Mask Ventilation During Lumbar Spine Neurosurgery in Knee-Chest Position is Feasible.

Background: This study describes our experience with laryngeal mask (LM) inserted after anesthetic induction in patients already in knee-chest position for lumbar neurosurgery.

Methods: Airway management (need for LM repositioning, orotracheal intubation because of failed LM insertion), anticipated difficult airway, and airway complications were registered. Statistics were compared between groups with the t test or the χ test, as appropriate.

[Diagnostic yield and postoperative management of patients submitted to brain biopsy in a university hospital].

Objective: To assess the diagnostic yield and the incidence of perioperative complications in patients undergoing an open or closed cerebral biopsy and to determine the length of intensive care monitoring, for early diagnosis and fast management of perioperative complications.

Material And Method: This was a retrospective analysis of all the patients that underwent brain biopsy between January 2006 and July 2012. We recorded demographic data, comorbidities, modality of biopsy, intraoperative clinical data, histological results, computed tomography scanning findings and occurrence, and type of perioperative complications and moment of appearance.

ProSeal Laryngeal Mask Airway Attenuates Systemic and Cerebral Hemodynamic Response During Awakening of Neurosurgical Patients: A Randomized Clinical Trial.

Background: Extubation and emergence from anesthesia may lead to systemic and cerebral hemodynamic changes that endanger neurosurgical patients. We aimed to compare systemic and cerebral hemodynamic variables and cough incidence in neurosurgery patients emerging from general anesthesia with the standard procedure (endotracheal tube [ETT] extubation) or after replacement of the ETT with a laryngeal mask airway (LMA).

Materials And Methods: Forty-two patients undergoing supratentorial craniotomy under general anesthesia were included in a randomized open-label parallel trial.

Critical closing pressure during intracranial pressure plateau waves.

Background: Critical closing pressure (CCP) denotes a threshold of arterial blood pressure (ABP) below which brain vessels collapse and cerebral blood flow ceases. Theoretically, CCP is the sum of intracranial pressure (ICP) and arterial wall tension (WT). The aim of this study is to describe the behavior of CCP and WT during spontaneous increases of ICP, termed plateau waves, in order to quantify ischemic risk.

Reliability of the blood flow velocity pulsatility index for assessment of intracranial and cerebral perfusion pressures in head-injured patients.

Background: It has been postulated that the Gosling pulsatility index (PI) assessed with transcranial Doppler (TCD) has a diagnostic value for noninvasive estimation of intracranial pressure (ICP) and cerebral perfusion pressure (CPP).

Objective: To revisit this hypothesis with the use of a database of digitally stored signals from a cohort of head-injured patients.

Methods: We analyzed prospectively collected data of patients admitted to the Cambridge Neuroscience critical care unit who had continuous recordings of arterial blood pressure, ICP, and cerebral blood flow velocities (FVs) using TCD.

The relationship between cerebral blood flow autoregulation and cerebrovascular pressure reactivity after traumatic brain injury.

Background: Cerebrovascular pressure reactivity is the principal mechanism of cerebral autoregulation. Assessment of cerebral autoregulation can be performed by using the mean flow index (Mx) based on transcranial Doppler ultrasonography. Cerebrovascular pressure reactivity can be monitored by using the pressure reactivity index (PRx), which is based on intracranial pressure monitoring.

Ultrasound-guided popliteal sciatic block with a single injection at the sciatic division results in faster block onset than the classical nerve stimulator technique.

Background: For successful, fast-onset sciatic popliteal block (SPB), either a single injection above the division of the sciatic nerve, or 2 injections to block the tibial nerve (TN) and common peroneal nerve (CPN) separately have been recommended. In this study, we compared the traditional nerve stimulator (NS)-guided SPB above the division of the sciatic nerve with the ultrasound (US)-guided block with single injection of local anesthetic (LA) between the TN and CPN at the level of their division. We hypothesized that US-SPB with a single injection between TN and CPN would result in faster block onset than a single-injection NS-SPB.

Transcranial Doppler pulsatility index: what it is and what it isn't.

Background: Transcranial Doppler (TCD) pulsatility index (PI) has traditionally been interpreted as a descriptor of distal cerebrovascular resistance (CVR). We sought to evaluate the relationship between PI and CVR in situations, where CVR increases (mild hypocapnia) and decreases (plateau waves of intracranial pressure-ICP).

Methods: Recordings from patients with head-injury undergoing monitoring of arterial blood pressure (ABP), ICP, cerebral perfusion pressure (CPP), and TCD assessed cerebral blood flow velocities (FV) were analyzed.

Pressure inside the neuroendoscope: correlation with epidural intracranial pressure during neuroendoscopic procedures.

Background: During neuroendoscopic procedures, pressure inside the neuroendoscope (PIN) monitored through the irrigation channel correlates with the occurrence of postoperative complications. Our aim was to analyze the reliability of PIN measurement as a surrogate for intracranial pressure (ICP) by comparing PIN with simultaneously epidural ICP measurement as the standard.

Methods: Seventeen consecutive patients undergoing neuroendoscopy were studied prospectively.

Portal hyperperfusion: mechanism of injury and stimulus for regeneration in porcine small-for-size transplantation.

Understanding the pathogenesis of small-for-size (SFS) syndrome is critical to expanding the applicability of partial liver transplantation. We aimed to characterize its acute presentation and association with alterations in hepatic hemodynamics, microstructure, and regeneration in a porcine model. Eighteen SFS liver transplants were performed.