Platinum-iridium subdermal magnetic resonance imaging-compatible needle electrodes are suitable for intraoperative neurophysiological monitoring during image-guided surgery with high-field intraoperative magnetic resonance imaging: an experimental study.

Neurosurgery aims to achieve maximal tumor resection while preserving neurological function. Tools such as neuronavigation, high-field intraoperative magnetic resonance imaging (iMRI), and intraoperative neurophysiological monitoring (IOM) have consistently helped to achieve this goal, but integration has often been difficult. Surgery of eloquent areas requires IOM, which in an operating theater equipped with high-field (1.5-T) iMRI could present several issues. To identify the electrodes types more suitable for IOM in a high-field iMRI operating theater by performing an experimental study on phantoms, to report our experience with platinum-iridium (Pt/Ir) electrodes during surgery, and to prove that integration between IOM with Pt/Ir electrodes and high-field iMRI is safe and reliable. Electrodes of different materials (gold, Pt/Ir, and stainless steel) were tested on jelly phantom and apples to evaluate their safety and compatibility. Subsequently, electrodes were tested on 5 healthy volunteers before being used on patients. None of the different electrodes presented thermal instability, and no damage to the volunteers' skin occurred. Stainless steel electrodes caused severe imaging distortion. Gold electrodes had no distortion, but their high cost makes their use in routine surgery unaffordable. Pt/Ir electrodes are significantly less expensive than gold electrodes and were completely safe, compatible, and suitable for use in an operating theater with high-field iMRI, providing excellent IOM and mild interference that did not affect the quality of intraoperative imaging. We suggest the use of Pt/Ir electrodes for IOM in 1.5-T iMRI suites. DTI, diffusion tensor imagingiMRI, intraoperative magnetic resonance imagingIOM, intraoperative neurophysiological monitoring

Intraoperative DTI and brain mapping for surgery of neoplasm of the motor cortex and the corticospinal tract: our protocol and series in BrainSUITE

We report our preliminary series of patients treated for lesions involving the motor cortex and the corticospinal tract in BrainSuite, with intraoperative MRI, tractography and "neuronavigated" electrophysiological cortical and subcortical mapping. An exact localization of the cortical and subcortical functional areas is mandatory for executing surgery of intra-parenchymal neoplasm involving the motor cortex and the corticospinal tract. Nowadays modern technology offers a variety of tools to reduce as much as possible postoperative deficits during surgery of cerebral eloquent areas. From December 2008 and June 2010, 18 patients underwent functional surgery, for neoplasm involving the motor cortex and/or the subcortical pathway, in BrainSuite. Our preliminary series include 14 gliomas and 4 metastases; Table 1 summarizes all of the data. We included in this series patients with complete removal of lesions of eloquent areas with an average distance from the corticospinal tract of 4 mm. Six neoplasms were considered in contact and/or involving the motor cortex, while in 18 cases (100%) the tumour involved eloquent areas concerning the corticospinal tract. All of the patients underwent complete removal of the lesion as subsequently demonstrated by intraoperative postsurgical MRI. Our series highlights the good integration and the high compatibility between BrainSUITE with 1.5 T intraoperative magnetic field and neurophysiological monitoring. We strongly believe that intraoperative MRI with DTI allows us to treat complex surgery tumours that without its auxilium we would not be able to deal with

The effect of dexmedetomidine on status epilepticus in a patient with anti-NMDA receptor encephalitis

The effect of dexmedetomidine on status epilepticus in a patient with anti-NMDA receptor encephalitis A 35-yr-old Caucasian woman was hospitalized in psychiatry, after childbirth, for psychomotor agitation, visual hallucinations, and incoherent speech. On admission, electroencephalography, brain imaging and cerebrospinal fluid examination showed no abnormalities. On day 7, she was found unconscious, and admitted to the intensive care unit (ICU). She developed status epilepticus alternating with periods of agitation. SE persisted despite combined treatment with phenytoin sodium, levetiracetam, and delorazepam. Intravenous dexmedetomidine (0.4 lgkg-1hr-1) was administrated for conscious sedation, and improvement from the SE was observed in 30min,as documented with EEG tracings. Electroencephalography spectral analysis showed a significant increase in beta activity, which is typical of dexmedetomidine. SE relapsed after dexmedetomidine interruption and resolved when the infusion was restarted. Anti-N-methyl-D-aspartate receptor (NMDA-R) antibodies were detected in the CSF. N-methyl-D-aspartate receptor antibodies are a rare cause of autoimmune encephalitis, often misdiagnosed with psychosis, which typically leads to seizures and drugresistant SE. Contradictory results have been reported on the effects of the alpha-2 agonist dexmedetomidine in epilepsy. In animals, dexmedetomidine has been shown both to reduce and increase the seizure threshold in local anestheticinduced epilepsy. Another question is the exact relationship between dexmedetomidine and NMDA-R. N-methyl-Daspartate receptors are ionotropic glutamate receptors that play a key role in excitatory synaptic transmission. Dexmedetomidine can depress NMDA-R-mediated transmission. Dexmedetomidine exerts its activity on G-protein coupled alpha-2 adrenoreceptors through inhibition of cyclic adenosine monophosphate and Our observations suggest a possible role for dexmedetomidine in the management of drug-resistant SE in the ICU. In patients with NMDA-R encephalitis and seizures, dexmedetomidine could be a useful bridge between typical pharmacological approaches and plasmapheresis

Improvement of neuroanatomy learning in first/second year medical students using BrainSUITE-aided lessons

There is consensus that neuroanatomy is one of most difficult branches of the undergraduate medical core curriculum. Even though interactive and multimedia teaching has now become available for the study of neuroanatomy, it is still hard to achieve a deep three dimensional comprehension, as it would be desiderable. Therefore, in order to either improve neuroanatomy learning and students’ motivation, neurosurgical images acquired using the Brain SUITE® operating theatre have been illustrated within the context of integrated neuroanatomy, neuroradiology and neurosurgery lessons of second year-course medical students at Sapienza University of Rome. Students’ agreement and satisfaction were evaluated by means of an anonymous questionnaire, according to the Likert scale. The questionnaire showed that textbooks, atlases and CD-ROMs are useful didactic tools for the general neuroanatomical knowledge, and to a lesser degree for the comprehension of topography. Students much appreciated the integration of neuroanatomical and neurosurgical images with the aid of the Brain SUITE® which made lessons challenging and innovative. In addition, the global evaluation of real inpatients, their surgery and their pre- and post-operatory periods, make students feeling as part of their future professional reality, further stimulating them to a deeper study. This basic-clinical and multimedia integration thus represents a good example of translational teaching

Standard awake surgery versus hypnosis aided awake surgery for the management of high grade gliomas: A non-randomized cohort comparison controlled trial

Hypnosis could extend the time of Intraoperative Neuropsychological Testing and Brain Mapping in Awake Surgery. A clinical validation for the Hypnosis aided AS (HAs) is still ongoing and further evidences are required. The objective of the present study is to compare two homogeneous cohorts of patients undergoing AS, the first with the aid of the hypnosis and the second according to a standard AS (SAs) protocols. The clinical, radiological and surgical data of two comparable procedures cohorts were retrospectively examined for the present study. All surgeries in Group A were performed with a HAs protocol. Procedures belonging to Group B were performed with a SAs protocol. Endpoints: to compare 1. Incidence of complications in the immediate postoperative period, 2. Clinical and neurological status in the immediate postoperative period and 30 days after surgery, 3. Duration of surgical interventions, 4. Extent of Resection (EOR). The final cohort is composed of 15 procedures; 6 belonging to Group A and 9 to Group B. The different methods outline statistically comparable results from the clinical (Neurological outcomes) both in the postoperative period and one month after surgery and from the surgical point of view (comparable EOR). The incidence of complications is comparable either. The duration of the procedures was significantly longer in HAs group. Hypnosis is a promising approach to increasing the duration of intraoperative "testability" of patients at the price of a longer operative time. A specific professional is needed to induce hypnosis in the difficult intraoperative setting