Training charter in epilepsy surgery added competence.

The present Training Charter in Epilepsy Surgery Added Competence constitutes the third stage of a program initiated by the European Society for Stereotactic and Functional Neurosurgery (ESSFN) and substantiated in close collaboration with the Union Européennedes Médecins Spécialists (UEMS) and the European Association of Neurosurgical Societies (EANS). This program aims to raise the standards of clinical practice by guiding education and quality control concepts. The particular sections of this Charter include: definitions and standards of added competence training, relations of the Epilepsy Unit with the Neurosurgical Department, duration of epilepsy surgery fellowship, institution and training program director requirements, operative totals for epilepsy surgery, educational program, individual requirements, and evaluation and qualification of the trainees. The specification of all these requirements is expected to improve harmonisation and quality of epilepsy surgery practice across Europe, and enhance the clinical activity and the scientific productivity of existing neurosurgical centres.

Transcranial alternating current stimulation reduces symptoms in intractable idiopathic cervical dystonia: a case study.

Idiopathic cervical dystonia (ICD) is a movement disorder often resulting in profound disability and pain. Treatment options include oral medications or other invasive procedures, whereas intractable ICD has been shown to respond to invasive (deep) brain stimulation. In the present blinded, placebo-controlled case study, transcranial direct current stimulation (tDCS) and transcranial alternating current stimulation (tACS) has been applied to a 54-year old patient with intractable ICD. Results showed that 15 Hz tACS had both immediate and cumulative effects in dystonic symptom reduction, with a 54% reduction in the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) total score, and a 75% in the TWSTRS Pain Scale. These effects were persistent at 30-days follow-up. This is the first report to demonstrate a significant and lasting therapeutic effect of non-invasive electrical brain stimulation in dystonia.

Twelve-year hospital outcomes in patients with idiopathic hydrocephalus.

OBJECTIVE: The aim of this study was to examine patients who were admitted for the first-ever shunting for idiopathic normal pressure hydrocephalus (INPH) during a 12-year period, in terms of variation rate, patient demographic characteristics, shunt procedures, postoperative complications, and hospital outcome. METHODS: An electronic database which included all shunted patients (1998 to 2009) was used to retrieve demographic, clinical, and hospital outcome data. INPH patient identification was based on clinical and imaging diagnostic criteria. RESULTS: INPH patients (n = 238) who had undergone shunting were identified. The mean age and male to female ratio of INPH patients were 73.3 (± 7) years and 1.28:1, respectively.The number of surgically managed INPH cases and proportion of INPH-related shunting procedures rose consecutively during the second and last third of the study period. Ventriculoperitoneal shunts (n = 129; 54.2%) were the most commonly used configurations, followed by ventriculoatrial (n = 108; 45.4%) and lumboperitoneal (n = 1; 0.4%). Intrahospital shunt-related complications were hematomas (0.84%), meningitis (0.42%), and status epilepticus (0.42%). A favorable outcome was reported for 66.8% of patients; 31.5% showed no change. Overall inpatient mortality was 1.7%. CONCLUSION: The quantitative findings indicate a progressive rise in the number of surgically managed INPH patients that parallels a rise in the proportion of INPH-related shunting procedures. Contributing factors are likely to include improved diagnosis and an increase in awareness of the INPH syndrome by referring physicians.

Current concepts on the mechanisms of dystonia and the beneficial effects of deep brain stimulation.

The application of lesioning procedures in the basal ganglia and, more recently, of deep brain stimulation (DBS) has revolutionalized dystonia treatment. However, our understanding of the mechanism of action of DBS is only minimal. This is largely due to a rudimentary understanding of dystonia pathophysiology itself, which in turn reflects an insufficient understanding of the functional significance of the cortico-striato-pallido-thalamocortical loops. The initial dystonia pathophysiology concept was one of changes in oscillation rate. Soon, it was realized that not only rate but also the pattern of basal ganglia activity is crucial in the etiology of the disease. The observations of altered somatosensory responsiveness and cortical neuroplasticity, along with the vast array of clinical phenotypes, imply the need for a wholistic neuronal pathophysiology model; one in which an underlying defect of basal ganglia function results in increased cortical excitability, misprocessing of sensory feedback, aberrant cortical plasticity, and ultimately clinical dystonia. This unified dystonia pathophysiology model, although simplistic, may provide the scaffold on which all incoming research and clinical data becomes united in a meaningful and practical way. In light of this model, the dramatic response of some forms of dystonia to pallidal stimulation, the time latency for the beneficial effect and even the presence of non-responders may be explained. Additionally, it may help in developing a rationale for more efficacious DBS programming, better selection of the timing of surgery, and more successful identification of those candidates that are most likely to respond to DBS.

Trigonal cavernous angioma: a short illustrated review.

PURPOSE: Intraventricular cavernomas are rare. Even more rare are those presenting in the trigone of the lateral ventricles. METHODS: We performed a search of the literature of the last 30 years and identified all cases of intraventricular cavernous angiomas. Trigonal cavernomas were separately identified and analysed. Our search yielded a total of 13 trigonal cavernomas. RESULTS: Of a total of 61 intraventricular cases, 13 were located in the trigone of the lateral ventricles. The most prominent presenting symptom was intracranial hypertension (68.9%), followed by seizures (18.2%) and hemorrhage (13.1%).The literature review revealed a trend of intraventricular cavernomas to present with intracranial hypertension rather than seizures or focal neurologic deficit, unlike their intraparenchymal counterparts. We feel that this difference has received little attention in the international literature. We discuss a possible pathogenetic mechanism for the presence of intracranial hypertension and address different aspects of diagnosis and treatment of this benign lesion. CONCLUSIONS: Trigonal cavernomas are benign lesions that have an excellent outcome after radical excision. Symptoms and signs of intracranial hypertension and hydrocephalus may be the prominent initial presentation of this rare ailment.

Serum biochemical markers of brain injury.

The diagnosis and assessment of brain damage is currently based on the clinical examination and the modern neuro-imaging techniques. Electrophysiology, haemodynamic monitoring and invasive neuromonitoring constitute additional tools for monitoring of the brain function and clinical course of the patient. However, despite the substantial progress, clinical and neuro-monitoring methods are quite often not sufficient to evaluate and quantify the severity of the initial and secondary destructive processes and hence they cannot guide efficient therapeutic measures and prognosticate effectively the outcome. During the last decades, researchers and clinicians have focused on specific markers of brain cell damage to improve the diagnosis and monitoring of neurological insults. Lactate dehydrogenase, creatine kinase, neuron specific enolase, have been proposed as potential markers of brain injury. More recently, other glial markers such as the Myelin Basic Protein, the glial fibrillary acidic protein and the S-100B protein have been measured in blood and used as surrogate biochemical markers for brain injury. This review summarizes published findings on the above brain specific serum biochemical markers with emphasis on those with clinical utility.

Cervical disc, mimicking nerve sheath tumor, with rapid spontaneous recovery: a case report.

The study design includes a case report and clinical discussion. The potential of acute disc herniations to regress spontaneously has been previously reported. However, the initial radiological presentation can be misleading, leading to therapeutic pitfalls, especially when the presence of myelopathy calls for early intervention. We present the case of a 46-year-old woman with a cervical intraspinal enhancing mass, associated enhancement of the C6 root and myelopathy, leading to the presumptive diagnosis of a nerve sheath tumor. The patient was offered surgery, which she denied. The patient returned 7 weeks later with significant clinical improvement. A subsequent magnetic resonance imaging depicted a herniated cervical disc and regression of myelopathy. Although spontaneous regression of disc prolapse and myelopathy have been previously reported, the initial radiological presentation and the short period of regression in this case highlight the need for a thorough understanding of the natural course of cervical disc herniations. Nonsurgical conservative observation should be considered an option for treatment for some cervical disc herniations that are likely to regress for very specific and predictable reasons.

Recurrence of trigeminal neuralgia due to an acquired arachnoid cyst.

We present the case of a 55-year-old female with pain recurrence after microvascular decompression for trigeminal neuralgia due to development of an arachnoid cyst. Radioimaging studies were inconclusive for vascular compression but showed evidence of fifth nerve distortion. The patient underwent surgical re-exploration, and a cystic lesion of thickened arachnoid containing cerebrospinal fluid was identified and excised. Postoperatively, the patient obtained pain relief. Arachnoid cyst formation may be a possible reason for pain recurrence after microvascular decompression for trigeminal neuralgia, especially when repeat neuroimaging does not show clear evidence of fifth nerve vascular compression. Direct compression from the cyst or arterial pulsation transmission through the cyst to the nerve may be the cause of recurrence.

Intracranial hemorrhagic arachnoid cyst: the role of diffusion-weighted imaging.

The majority of hemorrhagic arachnoid cysts are correlated with trauma or aneurysmal rupture. We report on a 35-year-old woman with acute headache and an intracranial mass lesion that was hyperdense in CT and hyperintense in conventional MRI images. The history and imaging were negative for trauma or vascular anomaly. Diffusion-weighted imaging (DWI) clearly demonstrated a large right anterior and middle cranial fossa arachnoid cyst with associated subacute intracystic hemorrhage without subdural hematoma. DWI offers invaluable information for the differential diagnosis of hemorrhagic arachnoid cysts from other extra-axial space-occupying lesions.

An introduction to neural networks surgery, a field of neuromodulation which is based on advances in neural networks science and digitised brain imaging.

Operative Neuromodulation is the field of altering electrically or chemically the signal transmission in the nervous system by implanted devices in order to excite, inhibit or tune the activities of neurons or neural networks and produce therapeutic effects. The present article reviews relevant literature on procedures or devices applied either in contact with the cerebral cortex or cranial nerves or in deep sites inside the brain in order to treat various refractory neurological conditions such as: a) chronic pain (facial, somatic, deafferentation, phantom limb), b) movement disorders (Parkinson's disease, dystonia, Tourette syndrome), c) epilepsy, d) psychiatric disease, e) hearing deficits, and f) visual loss. These data indicate that in operative neuromodulation, a new field emerges that is based on neural networks research and on advances in digitised stereometric brain imaging which allow precise localisation of cerebral neural networks and their relay stations; this field can be described as Neural networks surgery because it aims to act extrinsically or intrinsically on neural networks and to alter therapeutically the neural signal transmission with the use of implantable electrical or electronic devices. The authors also review neurotechnology literature relevant to neuroengineering, nanotechnologies, brain computer interfaces, hybrid cultured probes, neuromimetics, neuroinformatics, neurocomputation, and computational neuromodulation; the latter field is dedicated to the study of the biophysical and mathematical characteristics of electrochemical neuromodulation. The article also brings forward particularly interesting lines of research such as the carbon nanofibers electrode arrays for simultaneous electrochemical recording and stimulation, closed-loop systems for responsive neuromodulation, and the intracortical electrodes for restoring hearing or vision. The present review of cerebral neuromodulatory procedures highlights the transition from the conventional neurosurgery of resective or ablative techniques to a highly selective "surgery of networks". The dynamics of the convergence of the above biomedical and technological fields with biological restorative approaches have important implications for patients with severe neurological disorders.

Technical aspects and considerations of deep brain stimulation surgery for movement disorders.

Deep brain stimulation (DBS) represents one of the more recent advancements in Neurosurgery. Even though its most successful applications evolved in movement disorders (MDs), indications now include pain, psychiatric disorders, epilepsy, cluster headaches and Tourette syndrome. As this type of surgery gains popularity and the indications for DBS surgery increase, so it will certainly increase the number of neurosurgeons who will use this neuromodulatory technique. A detailed description of the technical aspects of the DBS procedure, as it is performed in our department, is presented. In our opinion, our method is a good combination of all the well-established necessary techniques in a cost-effective way. This technical article may be helpful to neurosurgeons considering to start performing this type of surgery. It could also prompt others who perform DBS regularly to express their views, and hence, lead to further refinement of this demanding procedure.

Vagus nerve stimulation for intractable epilepsy: outcome in two series combining 90 patients.

Vagus nerve stimulation (VNS) is the most widely used non-pharmacological treatment for medically intractable epilepsy and has been in clinical use for over a decade. It is indicated in patients who are refractory to medical treatment or who experience intolerable side effects, and who are not candidates for resective surgery. VNS used in the acute setting can both abort seizures and have an acute prophylactic effect. This effect increases over time in chronic treatment to a maximum at around 18 months. The evidence base supporting the efficacy of VNS is strong, but its exact mechanism of action remains unknown. A vagus nerve stimulator consists of two electrodes embedded in a silastic helix that is wrapped around the cervical vagus nerve. The stimulator is always implanted on the left vagus nerve in order to reduce the likelihood of adverse cardiac effects. The electrodes are connected to an implantable pulse generator (IPG) which is positioned subcutaneously either below the clavicle or in the axilla. The IPG is programmed by computer via a wand placed on the skin over it. In addition, extra pulses of stimulation triggered by a hand-held magnet may help to prevent or abort seizures. VNS is essentially a palliative treatment and the number of patients who become seizure free is very small. A significant reduction in the frequency and severity of seizures can be expected in about one third of patients and efficacy tends to improve with time. Vagus nerve stimulation is well tolerated and has few significant side effects. We describe our experience on the use of VNS on drug-resistant epilepsy in 90 patients treated in two departments (in Athens, Greece and Newcastle, England).

Neurosurgery for psychiatric disorders: from the excision of brain tissue to the chronic electrical stimulation of neural networks.

Neurosurgical treatment for psychiatric disorders has a long and controversial history dating back to antiquity. Both enthusiastic reports and social outcry have accompanied psychosurgical practice, particularly over the last century. Frontal lobotomy has probably been the only medical advance which was first awarded a Nobel prize in medicine and then irreparably stigmatized by scientific rejection and public criticism. In the present paper, the historical milestones of psychosurgery are briefly overviewed. The particular circumstances of the rise and fall of frontal lobotomy are also discussed. Furthermore, the clinical and surgical considerations of the four major psychosurgical procedures which are still in practice are presented. Over the last fifteen years, the advent of deep brain stimulation (DBS) methodology coupled with accurate stereotactic techniques and guided by elaborate neuroimaging methods have revolutionized neurosurgery, particularly for the alleviation of certain disabling movement disorders. Investigationally, chronic electrical stimulation of selected brain structures, clearly implicated in the pathophysiology of neuropsychiatric disorders, has already been applied with promising results. Given the tainted past of psychiatric neurosurgery, modern neuroscientists have to move forward cautiously, in a scientifically justified and ethically approved framework. The transition from the indiscriminate destruction of brain structures to the selected electrical modulation of neural networks lies ahead; contemporary neuroscientists would substantiate this aim but should remind the controversial history of the field.

Brain-computer interface: a reciprocal self-regulated neuromodulation.

Brain-computer interface (BCI) is a system that records brain activity and process it through a computer, allowing the individual whose activity is recorded to monitor this activity at the same time. Applications of BCIs include assistive modules for severely paralyzed patients to help them control external devices or to communicate, as well as brain biofeedback to self regulate brain activity for treating epilepsy, attention-deficit hyperactivity disorder (ADHD), anxiety, and other psychiatric conditions, or to enhance cognitive performance in healthy individuals. The vast majority of BCIs utilizes non-invasive scalp recorded electroencephalographic (EEG) signals, but other techniques like invasive intracortical EEG, or near-infrared spectroscopy measuring brain blood oxygenation are tried experimentally.

Connections of the basal ganglia with the limbic system: implications for neuromodulation therapies of anxiety and affective disorders.

The basal ganglia are best known for their role in motor planning and execution. However, it is currently widely accepted that they are also involved in cognitive and emotional behaviors. Parts of the basal ganglia play a key role in reward and reinforcement, addictive behaviors and habit formation. Pathophysiological processes underlying psychiatric disorders such as depression, obsessive compulsive disorder and even schizophrenia involve the basal ganglia and their connections to many other structures and particularly to the prefrontal cortex and the limbic system. In this article, we aim, on the basis of current research, to describe in a succinct manner the most important connections of the basal ganglia with the limbic system which are relevant to normal behaviors but also to psychiatric disorders. Currently, we possess sufficiently powerful tools that enable us to modulate brain networks such as cortex stimulation (CS) or deep brain stimulation (DBS). Notably, neuromodulation of basal ganglia function for the treatment of movement disorders has become a standard practice, which provides insights into the psychiatric problems that occur in patients with movement disorders. It is clear that a sound understanding of the currently available knowledge on the circuits connecting the basal ganglia with the limbic system will provide the theoretical platform that will allow precise, selective and beneficial neuromodulatory interventions for refractory psychiatric disorders.