Awake neurosurgery: an update.

Intraoperative brain mapping has the goal of aiding with maximal surgical resection of brain tumors while minimizing functional sequelae. Retrospective randomized studies on large populations have shown that this technique can optimize the surgical approach while reducing postoperative morbidity. During direct electrical stimulation of the language areas adjacent to the tumor, the patient should be collaborative and be able to speak to participate in language testing. Different anesthesiological protocols have been proposed to allow intraoperative brain mapping, which range from local anesthesia to conscious sedation or general anesthesia, with or without airway instrumentation. The most common intraoperative complications are seizure, respiratory depression, and patients' stress and discomfort. Since awake craniotomy carries both benefits and potential risks, the following factors are crucial in the management of patients: 1) careful selection of the patients and 2) communication between the anesthesiological and surgical teams. To date, there remains no consensus about the optimal anesthesiological regimen to use. Only prospective, multicentre randomized studies focused on evaluating the role of different anesthesiological techniques on intraoperative monitoring, postoperative deficits, and intraoperative complications can answer the question of which anesthesiological approach should be chosen when intraoperative brain mapping is requested.

Autologous transplantation of muscle-derived CD133+ stem cells in Duchenne muscle patients.

Duchenne muscular dystrophy (DMD) is a lethal X-linked recessive muscle disease due to defect on the gene encoding dystrophin. The lack of a functional dystrophin in muscles results in the fragility of the muscle fiber membrane with progressive muscle weakness and premature death. There is no cure for DMD and current treatment options focus primarily on respiratory assistance, comfort care, and delaying the loss of ambulation. Recent works support the idea that stem cells can contribute to muscle repair as well as to replenishment of the satellite cell pool. Here we tested the safety of autologous transplantation of muscle-derived CD133+ cells in eight boys with Duchenne muscular dystrophy in a 7-month, double-blind phase I clinical trial. Stem cell safety was tested by measuring muscle strength and evaluating muscle structures with MRI and histological analysis. Timed cardiac and pulmonary function tests were secondary outcome measures. No local or systemic side effects were observed in all treated DMD patients. Treated patients had an increased ratio of capillary per muscle fibers with a switch from slow to fast myosin-positive myofibers.

Cortical and subcortical motor mapping in rolandic and perirolandic glioma surgery: impact on postoperative morbidity and extent of resection.

AIM: Surgery for gliomas located inside or in proximity of motor cortex or tracts requires cortical and subcortical mapping to locate motor function; direct electrical stimulation of brain cortex or subcortical pathways allows identification and preservation of motor function. In this study we evaluated the effect which subcortical motor mapping had on postoperative morbidity and extent of resection in a series of patients with gliomas involving motor areas or pathways. METHODS: One hundred and forty-six patients were included in the study. Intraoperative findings of primary motor cortex or subcortical tracts were reported, together with incidence of new postoperative deficits at short (1 week) and long term (1 month) examination. The relationship between intraoperative identification of subcortical motor tracts and extent of resection was reported. RESULTS: The motor strip was found in 133 patients (91%) and subcortical motor tracts in 91 patients (62.3%). New immediate postoperative motor deficits were documented in 59.3% of patients in whom a subcortical motor tract was identified intra-operatively and in 10.9% of those in whom subcortical tracts were not observed; permanent deficits were observed in 6.5% and 3.5%, respectively. A total resection was achieved in 94.4% of patients with high-grade gliomas and in 46.1% of those with low-grade gliomas.

Early translaryngeal tracheostomy in patients with severe brain damage.

OBJECTIVES: To describe the effects of early translaryngeal tracheostomy on intracranial pressure (ICP), cerebral perfusion pressure (CPP), and jugular bulb saturation (SjO2); to identify the main mechanisms affecting ICP during tracheostomy; and to evaluate the long-term effects of tracheostomy on tracheal anatomy and function. DESIGN: Prospective, observational, clinical study. SETTING: Neurosurgical intensive care unit in a teaching hospital. PATIENTS: 20 patients admitted to the ICU because of head injury, subarachnoid hemorrhage, or brain tumor with a Glasgow Coma Scale less than 8. INTERVENTIONS: Patients underwent translaryngeal tracheostomy under strict neuromonitoring. MEASUREMENTS AND RESULTS: ICP rose significantly (p < 0.05) at the critical time of cannula placement while all other parameters remained stable. At this time five patients suffered intracranial hypertension (ICP > 20 mmHg). In one of them CPP dropped below 60 mmHg. Arterial CO2 tension (PaCO2) did not rise significantly. No other major complications were recorded during the procedures. Three months after tracheostomy normal findings were detected by tracheoscopy in all cases (11 patients could be examined). CONCLUSIONS: Translaryngeal tracheostomy, performed in selected patients when the risk of intracranial hypertension was reduced to the minimum, was well tolerated in the majority of cases and did not induce persistent intracranial disorders. However, ICP is affected by tracheostomy, and careful monitoring and patient selection is necessary. At follow-up no severe anatomical or functional damage was detected.

Neurophysiological consequences of three tracheostomy techniques: a randomized study in neurosurgical patients.

We describe the effects of different tracheostomy techniques on intracranial pressure (ICP), cerebral perfusion pressure (CPP), and cerebral extraction of oxygen. We attempted to identify the main mechanisms affecting intracranial pressure during tracheostomy. To do so we conducted a prospective, block-randomized, clinical study which took place in a neurosurgical intensive care unit in a teaching hospital. The patients studied consisted of thirty comatose patients admitted to the intensive care unit because of head injury, subarachnoid hemorrhage, or brain tumor. Ten patients per group were submitted to standard surgical tracheostomy, percutaneous dilatational tracheostomy or translaryngeal tracheostomy. In every technique a significant increase of ICP (P < .05) was observed at the time of cannula placement. Intracranial hypertension (ICP > 20 mm Hg) was more frequent in the percutaneous dilatational tracheostomy group (P < .05). Cerebral perfusion pressure dropped below 60 mm Hg in eleven cases, more frequently during surgical tracheostomy. Arterial tension of CO2 significantly increased in all three groups during cannula placement. No other major complications were recorded during the procedures. At follow-up no severe anatomic or functional damage was detected. We conclude that the three tracheostomy techniques, performed in selected patients where the risk of intracranial hypertension was reduced to the minimum, were reasonably tolerated but caused an intracranial pressure rise and cerebral perfusion pressure reduction in some cases.

Early postoperative seizures and endovenous phenytoin. Preliminary clinical data.

Early seizures represent a major complication in the post operative course of patients operated on for supratentorial tumors or AVMs. The real effectiveness of the AEDs prophylaxis to reduce the occurrence of post operative seizures is controversial. We proposed a prophylactic treatment with endovenous PHT consisting of two infusions of PHT (mean dosage of 18 mg/kg; mean time of 1 hr) perioperatively and during the first postoperative day. The interruption of the previous oral anticonvulsant treatment is not required. The endovenous route should permit a rapid reach of the therapeutical range. Sixty-six patients were treated. Fifty-one patients received two infusions and 15 patients only one infusion. The serum concentration of PHT performed at 24 hrs of operation was in most of patients (more than 80%) in the lower part of the therapeutical range while at 24 hrs of the second infusion was in the higher part or over the range. The overall prevalence of seizures was 10.6%. In the first group the incidence was 7.8%, in the second one was 20%. All the seizures appeared within 48 hrs of the operation. All the patients in the first group had single seizures, 2 patients of the second one experienced two seizures. No status epilepticus was observed. Alteration of consciousness and mild hypotension were the most common side effects. They never required major measurements and were mild, transient and completely reversible. We are starting with a randomized study based on a larger sample of patients which will allow a more reliable statistical analysis.

Efficacy and safety of flecainide in low-risk patients with chronic ventricular arrhythmias: a two-year follow-up.

The long-term efficacy and safety of flecainide (100 to 200 mg twice a day) were evaluated in 21 patients with high-grade, chronic ventricular arrhythmias who responded to and tolerated flecainide at a preliminary evaluation (200 mg, single oral dose). Antiarrhythmic response was evaluated at 3 days and 3, 6, 12, 18, and 24 months. The mean follow-up was 25 +/- 14 months (range 3 to 52). Four patients (19%) were excluded from efficacy analysis because of spontaneous decrease in baseline arrhythmia observed after 12 months of therapy. Effective arrhythmia suppression at both Holter monitoring and during exercise stress testing was maintained in 14 of 17 patients (82%). Mean frequency of premature ventricular contractions remained reduced by more than 95% throughout the follow-up. Five patients discontinued therapy between 3 and 18 months because of drug ineffectiveness (three patients, 18%) or side effects (two patients, 12%). In 12 patients (71%) long-term efficacy and tolerance were demonstrated. In no case was aggravation of arrhythmia or adverse cardiac effects observed. Side effects (5% to 29% of patients during follow-up) were usually minor and easily abolished by dosage reduction. In patients with chronic ventricular arrhythmias, flecainide maintained a favorable ratio between efficacy and side effects during a 2-year follow-up.