The transient intraluminal filament Middle Cerebral Artery Occlusion stroke model in rats. A step by step guide and technical considerations

OBJECTIVE

Stroke is a leading cause of disability and mortality worldwide. Related research, although already providing significant insights on the underlying pathophysiology and potential treatment strategies, is far from conclusive. In this respect, stroke models are proving of extreme significance for laboratories around the world. The scope of this article is to present in detail the most popular to date focal stroke model, the tifMCAO model in rats. This model mimics reliably stroke in humans and also approximates endovascular thrombectomy.

METHODS

The tifMCAO model was performed on Wistar rats with a weight of 300-400 gr. The surgical technique is described in a step-wise manner, while pictures and/or HD video accompany each step. Complete arteriotomy of the ECA stump is introduced during the procedure.

RESULTS

We performed the tifMCAO in 65 rats (male and female) involved in various experimental protocols. Although that initial mortality was 48%, practice reduced this number to10%. The mean procedural time was 53 min (range, 38 - 85 min). Stroke was confirmed in 87.5% of the cases.

CONCLUSIONS

The tifMCAO stroke model in rats is the most commonly utilized experimental model of focal ischemia because of its clinical relevance. We revisited the procedure and divided it, for instructional purposes, in 15 consecutive distinct steps.

Neuro-inflammatory Sequelae of Minimal Trauma in the Non-traumatized Human Brain: A Microdialysis Study

Cytokine measurement directly from the brain parenchyma by means of microdialysis has documented the activation of certain procedures in vivo, after brain trauma in humans. However, the intercalation of the micro-catheter insertion with the phenomena triggered by the head trauma renders the assessment of the findings problematic. The present study attempts to elucidate the pure effect of minimal trauma, represented by the insertion of the micro-catheter, on the non-traumatized human brain. Microdialysis catheters were implanted in 12 patients with drug-resistant epilepsy, and subjected to invasive electroencephalography with intracranial electrodes. Samples were collected during the first 5 days of monitoring. The dialysate was analyzed using bead flow cytometry, and the concentrations of interleukin (IL)-1, IL-6, IL-8, IL-10, IL-12, and tumor necrosis factor-α (TNF-α) were measured. The levels of IL-1 and IL-8 were found to be raised until 48 h post-implantation, and thereafter they reached a plateau of presumably baseline values. The temporal profile of the IL-6 variation was different, with the increase being much more prolonged, as its concentration had not returned to baseline levels at the fifth day post-insertion. TNF-α was found to be significantly raised only 2 h after implantation. IL-10 and IL-12 did not have any significant response to micro-trauma. These findings imply that the reaction of the neuro-inflammatory mechanisms of the brain exist even after minimal trauma, and is unexpectedly intense for IL-6. Questions may arise regarding the objectivity of findings attributed by some studies to inflammatory perturbation after head injury.

Deep Brain Stimulation-Related Surgical Site Infections: A Systematic Review and Meta-Analysis

BACKGROUND

Over the last decades, the increased use of deep brain stimulation (DBS) has raised concerns about the potential adverse health effects of the treatment. Surgical site infections (SSIs) following an elective surgery remain a major challenge for neurosurgeons. Few studies have examined the prevalence and risk factors of DBS-related complications, particularly focusing on SSIs.

OBJECTIVES

We systematically searched published literature, up to June 2020, with no language restrictions.

MATERIALS AND METHODS

Eligible were studies that examined the prevalence of DBS-related SSIs, as well as studies that examined risk and preventive factors in relation to SSIs. We extracted information on study characteristics, follow-up, exposure and outcome assessment, effect estimate and sample size. Summary odds ratios (sOR) and 95% confidence intervals (CI) were calculated from random-effects meta-analyses; heterogeneity and small-study effects were also assessed.

RESULTS

We identified 66 eligible studies that included 12,258 participants from 27 countries. The summary prevalence of SSIs was estimated at 5.0% (95% CI: 4.0%-6.0%) with higher rates for dystonia (6.5%), as well as for newer indications of DBS, such as epilepsy (9.5%), Tourette syndrome (5.9%) and OCD (4.5%). Similar prevalence rates were found between early-onset and late-onset hardware infections. Among risk and preventive factors, the perioperative implementation of intra-wound vancomycin was associated with statistically significantly lower risk of SSIs (sOR: 0.26, 95% CI: 0.09-0.74). Heterogeneity was nonsignificant in most meta-analyses.

CONCLUSION

The present study confirms the still high prevalence of SSIs, especially for newer indications of DBS and provides evidence that preventive measures, such as the implementation of topical vancomycin, seem promising in reducing the risk of DBS-related SSIs. Large clinical trials are needed to confirm the efficacy and safety of such measures.

Telemetric intracranial pressure monitoring: our experience with 22 patients investigated for intracranial hypertension

INTRODUCTION

We present the application of the Raumedic^® P-tel telemetric device that monitors Intracranial Pressure (ICP) over long periods, in 22 patients, with suspected intracranial hypertension.

METHODS

A telemetric device (Raumedic^®, Neurovent^® P-tel) was surgically implanted in 22 patients aged between 21 and 65 years. Among the patients, the inconclusive diagnosis of benign intracranial hypertension was set in 10, the possible diagnosis of postoperative hydrocephalus in 3, and the possible diagnosis of aqueduct stenosis in 2. Additionally, shunt malfunction and Normal Pressure Hydrocephalus (NPH) were investigated in 1 and 3 patients, respectively. Finally, 3 patients presented ventricular dilatation of unknown origin. All the individuals underwent a 3-day ICP recording within the nursing unit. Three more recordings were obtained over a period of 2-6 months at the outpatient base.

RESULTS

Analysis of the data excluded the diagnosis of intracranial hypertension in 12 patients. Elevated ICP values were confirmed in 10 patients. Subsequently, 7 of them underwent shunts' implantation, while 2 refused further neurosurgical treatment and 1 was treated with acetazolamide. Additionally, 1 patient who demonstrated normal ICP values, thus confirmed with NPH, underwent VP shunt implantation, while another 2 with similar characteristics refused further surgery. In our series the overall clinical complication rate after P-tel implantation was insignificant.

CONCLUSIONS

The telemetric device is safely implanted via a rather simple procedure. In selected patients, it could provide long-term ICP recordings, which are necessary to confirm diagnosis and guide to the appropriate treatment.

Anterior Cervical Discectomy and Fusion combined with thyroid gland surgery, a tailored case and literature review

Background

Nowadays, Anterior Cervical Discectomy and Fusion (ACDF) is considered a routine procedure. However, unexpected difficulties do occasionally arise, especially when anterior neck pathologies or anatomical variations are encountered. In such cases, proactive thinking will allow surgeons to tailor appropriately their approach and eliminate surgical risks.

Case presentation

We present the case of a 50-year-old male patient suffering from left upper limb radiculopathy that underwent a C7-T1 ACDF combined with a hemithyroidectomy. Excision of the right thyroid lobe was offered to the patient because of a goiter found during the preoperative work-up. Furthermore, the hemithyroidectomy provided a wide surgical field so the ACDF performed without excreting excessive traction to the adjacent neck structures.

Conclusions

The patient had an uncomplicated post-operative. To our knowledge this is the first report of a planned hemithyroidectomy being carried out as the first step towards an ACDF procedure.

Intrathecal Baclofen Therapy for Painful Muscle Spasms in a Patient with Friedreich's Ataxia

Friedreich's ataxia (FA) is the most frequent hereditary ataxia syndrome, while painful muscle spasms and spasticity have been reported in 11-15% of FA patients. This report describes the successful management of painful spasms in a 65-year-old woman with FA via intrathecal baclofen (ITB) therapy following unsuccessful medical treatments. To our knowledge, this is the third reported case in the literature. Unfortunately, the pathophysiological characteristics of muscle spasms in FA are not well explored and understood while the therapeutic mechanisms of the different treatments are rather vague. Taking into consideration the suggested spinal atrophy in FA, the clinical resemblance of FA and chronic spinal injury muscle spasms, together with the rapid ITB therapy effectiveness in alleviating FA muscle spasms, we attempted to suggest a putative pathophysiological mechanism acting at the spinal level and possibly explained by the presence of independent spinal locomotor systems producing muscle spasms. Specifically, overexcitement of these centers, due to loss of normal regulation from upper CNS levels, may result in the uncontrolled firing of secondary motor neurons and may be the key to producing muscle spasms. However, further research under experimental and clinical settings seems to be necessary.

A giant pseudoaneurysm of the occipital artery

Background

Pseudoaneurysms of the occipital artery (OA) are extremely rare and can occur following head trauma or iatrogenic injury; OA anatomy seems to play a crucial role in their pathogenesis.

Case Description

This report describes the case of a 76-year-old patient with a giant OA pseudoaneurysm secondary to a head injury the patient had sustained 1 month earlier. After radiological confirmation via ultrasonography (US) and computed tomography angiography (CTA), the patient underwent surgery for resection of the lesion. An uneventful postoperative course with no recurrence was confirmed at 1 and 2-month follow-up visits.

Conclusions

Despite their rarity, pseudoaneurysms of the OA should be considered in the differential diagnosis of patients presenting with an occipital pulsatile mass. Prompt management reduces the risk of a serious hemorrhage. In our case, considering the size of the lesion, surgical resection seemed to be the only reasonable option.

Epidemiology of First Epileptic Seizures in the Northern Aegean Island of Lesvos, Greece

We aimed at establishing the epidemiologic profile of first epileptic seizures (FES) in the Greek island of Lesvos. During a 1-year period (01/06/2010 to 31/05/2011), cases of FES admitted to the Lesvos General Hospital/addressed by general practitioners/private neurologists were prospectively identified. A total of 45 cases (30 males and 15 females; mean age ± SD of 59.4 ± 28.4 and 58.9 ± 26.8 years, respectively), were collected. The FES incidence rate was 52.1 (95% CI 37-67) per 10⁵ persons. Provoked and unprovoked FES had an incidence of, 16.2 and 35.9 cases per 10⁵ persons, respectively. Following age-adjustment to the 2000 US census population, incidence rates of FES (all types combined) were, 40.5 (95% CI 28-56) per 10⁵ persons. Cerebrovascular disease (CVD) was the most prevalent etiologic factor. The present findings indicate a low-ranking incidence of FES in the studied population and highlight CVD as a leading causative factor.

The Insertion of Electrodes in the Brain for Electrophysiological Recording or Chronic Stimulation Is Not Associated With Any Biochemically Detectable Neuronal Injury

OBJECTIVE

The aim of this study was to evaluate the degree of brain tissue injury that could be potentially induced by the introduction of a) microrecording electrodes, b) macrostimulation electrodes, or c) chronic stimulation electrodes. We aimed to evaluate whether the use of five simultaneous microrecording tracks is associated with any brain injury not detectable by conventional imaging such as CT or MRI.

MATERIALS AND METHODS

The study included 61 patients who underwent surgery for implantation of 121 DBS leads. In all cases, five simultaneous tracts were utilized for microelectrode recordings. All patients underwent measurements of serum S-100b at specific time points as follows: a) prior to the operation, and b) intraoperatively at specific stages of the procedure: 1) after opening the burr hole, 2) after the insertion of microrecording electrodes, 3) during macrostimulation, 4) at the end of the operation, and 5) on the first postoperative day.

RESULTS

The levels of serum S-100B protein remained within the normal range during the entire period of investigation in all patients with the exception of two cases. In both patients, the procedure was complicated by intraparenchymal hemorrhage visible in neuro-imaging. The first patient developed a small intraparenchymal hemorrhage, visible on the postoperative MRI, with no neurological deficit. The second patient experienced a focal epileptic seizure after the insertion of the right DBS chronic lead and the postoperative CT scan revealed a right frontal lobe hemorrhage.

CONCLUSION

These results strongly indicate that the insertion of either multiple recording electrodes or the implantation of chronic electrodes in DBS does not increase the risk of brain hemorrhage or of other intracranial complications, and furthermore it does not cause any biochemically detectable brain tissue damage.

Approaching the Atrium Through the Intraparietal Sulcus: Mapping the Sulcal Morphology and Correlating the Surgical Corridor to Underlying Fiber Tracts

BACKROUND: Although the operative corridor used during the intraparietal transsulcal approach to the atrium has been previously investigated, most anatomical studies focus on its relationship to the optic radiations.

OBJECTIVE: To study the intraparietal sulcus (IPS) morphology and to explore the subcortical anatomy with regard to the surgical trajectory used during the intraparietal transsulcal tranventricular approach.

METHODS: Twenty-five adult, formalin fixed, cerebral hemispheres were investigated. Fifteen underwent the Klingler procedure and were dissected in a lateromedial direction using the fiber microdissection technique. The trajectory of the dissection resembled that of real operative settings. The remaining 10 hemispheres were cut along the longitudinal axis of the sulcus in order to correlate its surface anatomy to corresponding parts of the ventricular system.

RESULTS: IPS demonstrated an interrupted course in 36% of the specimens while its branching pattern was variable. The sulcus anterior half was found to overly the atrium in all occasions. Four discrete, consecutive white matter layers were identified en route to the atrium, ie, the arcuate fibers, the arcuate segment of the superior longitudinal fasciculus, the corona radiata and tapetum, with the arcuate segment being near to the dissection trajectory.

CONCLUSION: Given the angle of brain transgression during the intraparietal approach, we found the optimal dissection area to be the very middle of the sulcus. The IPS–postcentral sulcus meeting point, in contrast to previous thought, proved to risk potential injury to the arcuate segment of the superior longitudinal fasciculus, thus affecting surgical outcome.

Algorithmic design of a noise-resistant and efficient closed-loop deep brain stimulation system: A computational approach

Advances in the field of closed-loop neuromodulation call for analysis and modeling approaches capable of confronting challenges related to the complex neuronal response to stimulation and the presence of strong internal and measurement noise in neural recordings. Here we elaborate on the algorithmic aspects of a noise-resistant closed-loop subthalamic nucleus deep brain stimulation system for advanced Parkinson’s disease and treatment-refractory obsessive-compulsive disorder, ensuring remarkable performance in terms of both efficiency and selectivity of stimulation, as well as in terms of computational speed. First, we propose an efficient method drawn from dynamical systems theory, for the reliable assessment of significant nonlinear coupling between beta and high-frequency subthalamic neuronal activity, as a biomarker for feedback control. Further, we present a model-based strategy through which optimal parameters of stimulation for minimum energy desynchronizing control of neuronal activity are being identified. The strategy integrates stochastic modeling and derivative-free optimization of neural dynamics based on quadratic modeling. On the basis of numerical simulations, we demonstrate the potential of the presented modeling approach to identify, at a relatively low computational cost, stimulation settings potentially associated with a significantly higher degree of efficiency and selectivity compared with stimulation settings determined post-operatively. Our data reinforce the hypothesis that model-based control strategies are crucial for the design of novel stimulation protocols at the backstage of clinical applications.

Efficacy, complications and cost of surgical interventions for idiopathic intracranial hypertension: a systematic review of the literature

BACKGROUND

To define the efficacy, complication profile and cost of surgical options for treating idiopathic intracranial hypertension (IIH) with respect to the following endpoints: vision and headache improvement, normal CSF pressure restoration, papilloedema resolution, relapse rate, operative complications, cost of intervention and quality of life.

METHODS

A systematic review of the surgical treatment of IIH was carried out. Cochrane Library, MEDLINE and EMBASE databases were systematically searched from 1985 to 2014 to identify all relevant manuscripts written in English. Additional studies were identified by searching the references of retrieved papers and relative narrative reviews.

RESULTS

Forty-one (41) studies were included (36 case series and 5 case reports), totalling 728 patients. Three hundred forty-one patients were treated with optic nerve sheath fenestration (ONSF), 128 patients with lumboperitoneal shunting (LPS), 72 patients with ventriculoperitoneal shunting (VPS), 155 patients with venous sinus stenting and 32 patients with bariatric surgery. ONSF showed considerable efficacy in vision improvement, while CSF shunting had a superior headache response. Venous sinus stenting demonstrated satisfactory results in both vision and headache improvement along with the best complication profile and low relapse rate, but longer follow-up periods are needed. The complication rate of bariatric surgery was high when compared to other interventions and visual outcomes have not been reported adequately. ONSF had the lowest cost.

CONCLUSIONS

No surgical modality proved to be clearly superior to any other in IIH management. However, in certain contexts, a given approach appears more justified. Therefore, a treatment algorithm has been formulated, based on the extracted evidence of this review. The traditional treatment paradigm may need to be re-examined with sinus stenting as a first-line treatment modality.

Preoperative neuropsychological presentation of patients with refractory frontal lobe epilepsy

BACKGROUND

This study investigated whether certain cognitive deficits are associated with frontal lobe epilepsy (FLE) aiming to contribute with localization data to the preoperative assessment of epilepsy surgery candidates.

METHODS

We evaluated 34 patients with refractory FLE, 37 patients with refractory medial temporal lobe epilepsy (MTLE), and 22 healthy individuals in attention, psychomotor speed, motor function, verbal memory span, verbal fluency, response inhibition/interference, concept formation and set shifting, anticipation and planning, global memory.

RESULTS

Neuropsychological performances of FLE and MTLE were similar, with the only exception the WCST-number of categories index, measuring mental flexibility, in which MTLE patients performed significantly worse than FLE patients. Left-FLE patients presented more perseverative responding compared to both other patient groups and healthy controls (HCs), while left-MTLE patients showed worse sorting abilities than the other epilepsy groups.

CONCLUSIONS

Our findings suggest a weak cognitive differentiation between FLE and MTLE, probably attributed to the intricate nature of fronto-temporal connectivity frequently resulting in overlapping deficits as well as the confounding effects of seizure-related variables. In clinical practice, a highly individualized (idiographic) neuropsychological approach along with the inclusion of concurrent EEG recordings (e.g., interictal coupling) may be of help for neuropsychologists in identifying FLE patients from those with medial temporal pathology presenting frontal dysfunction as a secondary cognitive symptom.

The incidence of the first-ever stroke in a Mediterranean island population: the isle of Lesvos stroke study

BACKGROUND

There is a paucity of research on the incidence and distribution of stroke types in Greece. This is the first study investigating stroke incidence in a Greek island, the Northern Aegean island of Lesvos (Eastern Mediterranean Sea).

METHODS

A multisource, prospective population-based register was established and subjects with first-ever stroke (FES) between June 1st 2010 and May 31st 2011 were identified.

RESULTS

197 FES subjects registered, 112 males and 85 females (mean age ± SD = 75 ± 12 years). Cerebral infarction was diagnosed in 77.7%, intracerebral hemorrhage in 12.7%, subarachnoid hemorrhage in 2.5%; undetermined stroke accounted for 7.1%. The crude annual incidence rates of FES were 227.9 (95% CI 196-260) per 100,000. Following age- and gender-standardization to the 'European' population, FES incidence rates were 117 (95% CI 99-136). Early case fatality was 20.81% (95% CI 16-27%).

CONCLUSIONS

The present findings indicate that the incidence of FES in the studied Mediterranean population is at the low end of the range of estimates established by recent European registers. The results of the present study extend the limited epidemiological data on stroke in Greece and can help guide future monitoring, prevention and treatment strategies.

Dynamics of regional brain activity in epilepsy: a cross-disciplinary study on both intracranial and scalp-recorded epileptic seizures

OBJECTIVE

Recent cross-disciplinary literature suggests a dynamical analogy between earthquakes and epileptic seizures. This study extends the focus of inquiry for the applicability of models for earthquake dynamics to examine both scalp-recorded and intracranial electroencephalogram recordings related to epileptic seizures.

APPROACH

First, we provide an updated definition of the electric event in terms of magnitude and we focus on the applicability of (i) a model for earthquake dynamics, rooted in a nonextensive Tsallis framework, (ii) the traditional Gutenberg and Richter law and (iii) an alternative method for the magnitude-frequency relation for earthquakes. Second, we apply spatiotemporal analysis in terms of nonextensive statistical physics and we further examine the behavior of the parameters included in the nonextensive formula for both types of electroencephalogram recordings under study.

MAIN RESULTS

We confirm the previously observed power-law distribution, showing that the nonextensive formula can adequately describe the sequences of electric events included in both types of electroencephalogram recordings. We also show the intermittent behavior of the epileptic seizure cycle which is analogous to the earthquake cycles and we provide evidence of self-affinity of the regional electroencephalogram epileptic seizure activity.

SIGNIFICANCE

This study may provide a framework for the analysis and interpretation of epileptic brain activity and other biological phenomena with similar underlying dynamical mechanisms.

Intrathecal baclofen associated with improvement of consciousness disorders in spasticity patients

OBJECTIVE

Intrathecal baclofen (ITB) pump is a therapeutic option for persistent vegetative state and minimal conscious state patients that have associated spasticity. We investigated whether this treatment modality can affect their level of consciousness.

METHOD

In this prospective, open label, observational study, we implanted ITB pumps for the treatment of spasticity in eight patients with disorders of consciousness (vegetative state and minimally conscious state) and we followed them with the Coma Recovery Scale-Revised, the Eastern Cooperative Oncology Group (ECOG) performance scale, and the Modified Ashworth spasticity scale. Baclofen dose and complications also were noted.

RESULTS

The offending pathologies were traumatic brain injury in six, anoxia due to cardiac arrest in one, acute obstructive hydrocephalus in one. Two of the patients showed a marked, persistent improvement that fulfilled the criteria of emergence from minimally conscious state. Two of patients had their ITB pumps prematurely removed because of complications. The ECOG score was 4 for all patients and did not change during the study.

CONCLUSION

ITB might be associated with a significant improvement in the disorder of consciousness of two patients from a total of six that had a chronic ITB treatment.

Simulating memory outcome before right selective amygdalohippocampectomy

In this paper we present the case of a left-sided speech dominant patient with right medial temporal sclerosis (RMTS) and pharmacoresistant epilepsy who showed improved verbal memory during intracarotid amobarbital test (IAT) at his right hemisphere as compared with his own performance before the drug injection (baseline), as well as after right selective amygdalohippocampectomy. We suggest that the defective verbal memory shown by this patient is due to abnormal activity of his right hippocampus that interfered with the function of his left hippocampus. This hypothesis was demonstrated by the fact that disconnection of the two hippocampi, either by anesthetisation or by resection of the right hippocampus, disengaged the left hippocampus and, consequently improved its function. This paper main objective is twofold: first to contribute to the field of neuropsychology of epilepsy surgery by emphasising on postoperative memory outcomes in right medial temporal lobe epilepsy (RMTLE) patients, particularly those undergoing amygdalohippocampectomy, as the pattern of memory changes after resection of the right temporal lobe is less clear; second, by focusing on memory performance asymmetries during IAT, and comparatively considering them with neuropsychological memory performance, because of their possible prognostic-simulating value.

The Evangelismos hospital central nervous system tumor registry: Analysis of 1414 cases (1998-2009)

Background:

The Evangelismos Hospital central nervous system (CNS) Tumor Registry represents the current effort of the Departments of Neurosurgery and Pathology to collect data for primary and metastatic CNS tumor patients. In the present study, 12-year hospital data (1998-2009) were reviewed and analyzed.

Methods:

Patients that underwent surgery for CNS tumors for the first time were identified. Histologically confirmed tumor rates by age and gender were compared. Time trends in annual rates for specific tumor types were investigated. In-hospital mortality rates and length of hospital stay were analyzed by age and gender and their putative variations across the study period investigated.

Results:

A total of 1414 patients (age 15-89 years) were identified. The most frequently encountered histologies were gliomas and meningiomas, accounting for, respectively, 32.8% and 29.1% of the total sample. A greater proportion of meningiomas was found in women; the proportion of glioblastomas and metastatic tumors, as well as of mixed gliomas, were greater in men. Increased rates of glioblastoma and meningioma with advancing age at diagnosis were also apparent. There were no significant variations in time trends for specific tumor types. In-hospital mortality was significantly higher for older patients (≥70 years). An increase in the length of hospital stay was apparent between the first and middle third of the study period.

Conclusions:

Analysis of tumor rates in relation to age at diagnosis and gender showed significant bias in accordance with salient literature. Available data indicated no significant variations in time trends for specific tumor types across the study period, while an adverse effect of advanced age on in-hospital mortality was shown. The present findings can guide the formulation of future treatment programs and preventive strategies and provide the basis for further intra- and/or interdepartmental research.

PlGF and sVEGFR-1 in chronic subdural hematoma: implications for hematoma development

Object

A considerable body of evidence indicates that inflammation and angiogenesis play a significant role in the development and progression of chronic subdural hematoma (CSDH). While various experimental and clinical studies have implicated placental growth factor (PlGF) in the processes that underpin pathological angiogenesis, no study has thus far investigated its expression in CSDH. The actions of PlGF and its related proangiogenic vascular endothelial growth factor (VEGF) are antagonized by a high-affinity soluble receptor, namely soluble VEGF receptor–1 (sVEGFR-1), and thus the ratio between sVEGFR-1 and angiogenic factors provides an index of angiogenic capacity.

Methods

In the present study, using an automated electrochemiluminescence assay, levels of PlGF and sVEGFR-1 were quantified in serum and hematoma fluid obtained in 16 patients with CSDH.

Results

Levels of PlGF and sVEGFR-1 were significantly higher in hematoma fluid than in serum (p < 0.0001). In serum, levels of sVEGFR-1 were higher than those of PlGF (p < 0.0001), whereas in hematoma fluid this difference was not apparent. Furthermore, the ratio of sVEGFR-1 to PlGF was significantly lower in hematoma fluid than in serum (p < 0.0001).

Conclusions

Given previous evidence indicating a role for PlGF in promoting angiogenesis, inflammatory cell chemotaxis, and stimulation, as well as its ability to amplify VEGF-driven signaling under conditions favoring pathological angiogenesis, enhanced expression of PlGF in hematoma fluid suggests the involvement of this factor in the mechanisms of inflammation and angiogenesis in CSDH. Furthermore, a reduced ratio of sVEGFR-1 to PlGF in hematoma fluid is consistent with the proangiogenic capacity of CSDH. Future studies are warranted to clarify the precise role of PlGF and sVEGFR-1 in CSDH.

Ictal intracranial recording from a 'burned-out hippocampus'

OBJECTIVE

To present a case involving a discrepancy in the presurgical data of a patient suffering from pharmacoresistant mesial temporal lobe epilepsy.

CLINICAL PRESENTATION AND INTERVENTION

A 47-year-old, female patient with complex partial seizures since her twenties came to be evaluated in the Epilepsy Surgery Unit. The ictal electroencephalogram suggested a left temporal epileptogenic zone and the magnetic resonance image showed an abnormality in the right mesial temporal lobe. Intracranial monitoring revealed a pacemaker zone in the right hippocampus that discharged fast spreading to the left mesial temporal lobe, a phenomenon known as 'burned-out hippocampus'.

CONCLUSION

The intracranial recording, even though it is an invasive procedure, was necessary for the presurgical evaluation of our patient. This case demonstrates the risks of using surface electroencephalography to determine localization of epileptogenic zones.

The Hellenic and Hippocratic origins of the spinal terminology

Numerous Hellenic terms have been gradually adopted during the development of modern medical science. Moreover, there are a significant number of words that derive directly from the Hippocratic texts. Hippocrates (ca. 460-ca. 377 BC), revered as the father of medicine, and his followers left behind a valuable heritage of medical knowledge that, practically, laid the foundations of Western medicine. Their theories, collected in Corpus Hippocraticum, transformed medicine by adding, mainly, clinical observation and inductive reasoning as significant parts of medical diagnosis and treatment. Additionally, Hippocratic writings have provided an invaluable heritage of medical terms for all medical fields. The present article examines the Hellenic and Hippocratic terminology referring to the spine and how this vocabulary has influenced and dominated upon modern spinal onomatology.

Malignant neuroleptic syndrome following deep brain stimulation surgery: a case report

Background

The neuroleptic malignant syndrome is an uncommon but dangerous complication characterized by hyperthermia, autonomic dysfunction, altered mental state, hemodynamic dysregulation, elevated serum creatine kinase, and rigor. It is most often caused by an adverse reaction to anti-psychotic drugs or abrupt discontinuation of neuroleptic or anti-parkinsonian agents. To the best of our knowledge, it has never been reported following the common practice of discontinuation of anti-parkinsonian drugs during the pre-operative preparation for deep brain stimulation surgery for Parkinson's disease.

Case presentation

We present the first case of neuroleptic malignant syndrome associated with discontinuation of anti-parkinsonian medication prior to deep brain stimulation surgery in a 54-year-old Caucasian man.

Conclusion

The characteristic neuroleptic malignant syndrome symptoms can be attributed to other, more common causes associated with deep brain stimulation treatment for Parkinson's disease, thus requiring a high index of clinical suspicion to timely establish the correct diagnosis. As more centers become eligible to perform deep brain stimulation, neurologists and neurosurgeons alike should be aware of this potentially fatal complication. Timely activation of the deep brain stimulation system may be important in accelerating the patient's recovery.

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.

Infected internal pulse generator: Treatment without removal

Background:

One of the rare but devastating complications of deep brain stimulation (DBS) is internal pulse generator (IPG) infection. In the majority of the cases, removal of the device is required, despite appropriate antibiotic therapy. We demonstrate that eradication of an IPG infection is feasible without removal of the IPG device.

Case Description:

This article reports the authors’ experience on two patients who underwent DBS for advanced Parkinson's disease (PD) and, subsequently, suffered from infection and skin breakdown over the IPG. The patients were treated with antibiotic therapy, surgical revision of the wound, intraoperative disinfection of the IPG and relocation of the subcutaneous pocket. In both cases, the infection was eradicated and DBS therapy was continued uninterrupted.

Conclusion:

Although not generally recommended, DBS IPG may be salvaged in selected cases of superficial device infection. Our experience suggests that it is possible to treat the infection without removing the device. Such an approach decreases the morbidity, duration of hospital stay and health care costs.

The future of peripheral nerve stimulation

The field of peripheral nerve stimulation (PNS) is now experiencing a phase of rapid growth in number of patients, number of implanters, number of indications, and procedure types. This, however, appears to be only a beginning of major developments that could revolutionize the field of PNS. It is expected that the progress in PNS will continue simultaneously in several directions as new indications, new stimulation targets and new device designs evolve in the foreseeable future. Responding to a major need for safe and effective pain treatments and following a general trend toward less-invasive and nondestructive interventions, PNS has the potential of becoming a premier pain-relieving modality that will be used instead of or in combination with existing more established approaches such as spinal cord stimulation and pharmacological pain control. Recent technological advancements are cause for considerable optimism regarding the development of PNS and are likely to be a beginning of a major overhaul in our perception of PNS approaches. Expanding the number of applications will without question strengthen the field of PNS. The turning point, however, will not occur until sufficient scientific evidence is gathered to unequivocally prove its safety, clinical efficacy and cost-effectiveness, and when PNS applications become officially endorsed through regulatory approval of each indication. Such changes will allow implanters to use approved devices for approved indications--instead of the contemporary 'off-label' use--and at the same time give device manufacturers a chance to market these devices and support education on their appropriate use.

Bifocal cortical electrical stimulation for pain by interdural implantation of the electrodes

Chronic electrical cortical stimulation (ECS) is an evolving therapy for alleviating treatment-refractory chronic pain syndromes. In this report, the authors describe a modified technique of ECS that involves resection of dural strips and interdural placement of the electrodes as a patch, and bifocal stimulation by implanting 2 electrode strips, that is, one over the motor and one over the sensory cortices.

The technique was used in 4 patients with treatment-refractory pain syndromes: a 76-year-old woman with poststroke central pain, 2 women, (71 and 73 years old) with trigeminal pain, and a 44-year-old man with phantom limb pain. All 4 patients experienced a sustained significant improvement in the intensity of pain and have gained a substantially improved functionality and quality of life. An important finding in these patients was the constancy of impedance within a narrow values range throughout the postoperative period. For the cases, the follow-up exceeds 24, 15, 12, and 9 months. The factors affecting the efficacy of ECS are discussed. In the authors' opinion, interdural implantation of the electrodes holds the promise to improve the efficacy and consistency of ECS compared with the standard epidural or subdural implantation without increasing the risk of the procedure. The technical considerations and the potential therapeutic advantages of the interdural bifocal approach are discussed.

Surgical and hardware complications of deep brain stimulation. A seven-year experience and review of the literature

PURPOSE

Deep brain stimulation (DBS) has been established as a safe and efficient method for the treatment of various movement disorders. As the emerging applications continue to expand and more centers become eligible for the procedure, complication rates and complication avoidance become increasingly important. Our aim was to report the DBS-related complication in our department over the last 7 years, compare our rates with those reported in the literature, and highlight those practices that will aid complications avoidance.

PATIENTS AND METHODS

Since 2003, 106 patients underwent DBS for various pathologies in our department. There were 38 (36%) females and 68 (64%) males with a mean age of 57 years. Preoperative diagnoses included Parkinson's disease (n = 88), dystonia (n = 12), tremor (n = 3), epilepsy (n = 1), obsessive-compulsive disorder (n = 1), and central pain syndrome (n = 1). Surgical and hardware-related complications, their treatment, and outcome were recorded and compared with those reported in the literature.

RESULTS

There were 12 procedure-related complications (11.3% of patients, 5.7% of the procedures). These included death (n = 1), aborted procedure (n = 1), postoperative respiratory distress (n = 3), intracranial hemorrhage (n = 2), epilepsy (n = 1), postoperative confusion or agitation (n = 3), and malignant neuroleptic syndrome (n = 1). Hardware-related complications presented in 4.3% of the procedures and included infection (five patients, 4.7%), electrode breakage (0.94%), lead migration or misplacement (0.94%), and stricture formation (two patients, 1.9%).

CONCLUSIONS

Complication rates after DBS surgery remain low, proving that DBS is not only effective but also safe. Certain strategies do exist in order to minimize complications.

Predictors of long-term outcome in an elderly group after laminectomy for lumbar stenosis

Object

This is a retrospective long-term outcome study of results after laminectomy for lumbar spinal stenosis in an elderly group of patients. The study was designed to evaluate possible demographic, comorbidity, and clinical prognosticators for pain reduction and functional improvement in this population. Because the assessment of functional outcome in the elderly is complicated by several specific factors, the use of outcome measurement parameters should be revised and refined. Moreover, despite numerous relevant studies, the results of various techniques remain equivocal, particularly among the elderly, which renders the implementation of focused studies necessary. New data could be used to refine patient selection and choice of technique to improve prognosis.

Methods

During a 5-year period, lumbar laminectomies were performed in 182 elderly patients. Of these 182, 125 patients (68.8%) were followed up for a mean period of 60.8 months. The outcome was assessed by means of pain visual analog scale (VAS) pain score, Oswestry Disability Index (ODI), and patient satisfaction questionnaire, and results were correlated to demographic (age, sex), comorbidity (Charlson Comorbidity Index, diabetes, depression, and history of lumbar spine surgery), and clinical (main preoperative complaint, preoperative VAS score, and ODI) factors.

Results

In terms of the VAS score, 106 patients (84.8%) exhibited improvement at follow-up. The corresponding ODI improvement rate was 69.6% (87 patients). The mean VAS and ODI differences were 5.1 and 29.1, respectively. One hundred two patients (81.6%) were satisfied with the results of the operation. Univariate analysis for possible prognostic factors revealed the significant influence of low-back pain on VAS score (p = 0.024) and ODI (p < 0.001) not improving, while the ODI was also affected by sex (females had a poorer outcome [p = 0.019]). In contrast, patient satisfaction was not related to any of the preoperative parameters recorded; nevertheless, it was strongly related to all functional measurements on follow-up.

Conclusions

Considering the methodological issues of such studies, particularly in elderly patients, the authors conclude that the ODI is more sensitive than the VAS score in assessing prognostic value and that patient satisfaction is difficult to prognosticate, underscoring the particularities that this population presents regarding functionality assessment. Considering the prognostic value of preoperative factors, a negative influence of low-back pain and female sex is reported.

Restoration of erect posture by deep brain stimulation of the globus pallidus in disabling dystonic spinal hyperextension

Dystonia is a movement disorder notoriously difficult to treat. While primary dystonia is classically considered to respond well to deep brain stimulation (DBS), treatment of secondary dystonia yields variable results. Patient selection should be done on a case-by-case basis. Clearly, there is a need to accumulate additional information with regard to prognostic factors that may aid neurosurgeons in selecting those patients in whom the disorder is most likely to respond favorably to pallidal DBS.

The authors report the case of a 29-year-old man with secondary dystonia due to perinatal hypoxia. The most prominent symptom was what we have termed ectatocormia—that is, severe, fixed truncal hyperextension and retrocollis, exacerbated by phasic, twisting movements of the trunk and head. This made it impossible for the patient to maintain a normal upright posture or to walk. The patient underwent bilateral DBS of the globus pallidus internus (GPi), and the authors observed impressive improvement in motor abilities and function. The patient's body adopted the normal upright posture and he became able to walk again, 4 months after the commencement of GPi stimulation.

This report, along with others, emphasizes that the GPi as an ideal target for alleviating axial tonic symptoms. The presence of normal MR imaging findings, a phenotypical purity of predominantly dystonic symptoms, and a younger age seem to favor a positive outcome.

Restoration of erect posture in idiopathic camptocormia by electrical stimulation of the globus pallidus internus

The authors report on 2 young patients who developed drug-resistant idiopathic dystonic camptocormia (bent spine) and were treated successfully by deep brain stimulation (DBS) of the globus pallidus internus (GPi). The first patient, a 26-year-old woman, suffered for 3 years from such severe camptocormia that she became unable to walk and was confined to bed or a wheelchair. The second patient, a 21-year-old man, suffered for 6 months from less severe camptocormia; he was able to walk but only for short distances with a very bent spine, the arms in a parallel position to the legs, and the hands almost approaching the floor to potentially support him in case of a forward fall. Within a few days following DBS, both patients experienced marked clinical improvement. At most recent follow-up (44 months in one case and 42 in the other), the patients' ability to walk upright remained normal. Similar findings have only been reported recently in a few cases of camptocormia secondary to Parkinson disease or tardive dyskinesia. On the basis of the experience of these 2 idiopathic cases and the previously reported cases of secondary camptocormia with a favorable response to GPi DBS, the authors postulate that specific patterns of oscillatory activity in the GPi are vital for the maintenance of erect posture and the adoption of bipedal walking by humans.

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.

Complex neurobehavioural syndrome due to bilateral thalamic glioma

We present a 65-year-old female with bilateral thalamic astrocytoma. The unusual long survival of this patient allowed the manifestation of a complex neurobehavioural syndrome due to gradual involvement of several thalamic nuclei. An attempt is made to approach the complexity of symptoms according to the anatomical areas, nuclei and thalamic connections infiltrated.

Symptomatic syringomyelia secondary to clinically obscure infratentorial tumour

The formation of a cervical spinal cord syrinx as a result of an infratentorial mass, even though uncommon, has been reported in international literature. In such cases, syringomyelia is usually asymptomatic, while the tumour-related symptoms and signs predominate. We report a patient with a posterior fossa tumour and secondary syringomyelia. In this patient, syringomyelia symptoms and signs were present, and a cervical spine Magnetic Resonance Imaging (MRI) showed a large cervical syrinx. A more careful clinical examination though, revealed a sub-clinical posterior fossa syndrome and brain MRI revealed a large infratentorial meningioma. A posterior fossa craniotomy was performed, followed by complete tumour resection and almost complete remission of the syrinx and its related symptoms. The authors discuss the role of posterior fossa tumour induced tonsillar herniation in the development of secondary syringomyelia, the mechanisms leading to syrinx formation and the conditions that must be fulfilled for that to happen.

Occult traumatic dissection of vertebral artery with an excellent outcome

We present the case of a young male with severe head injury, cervico-thoracic fractures, and an initially unrecognized brainstem infarct due to unilateral dissection of vertebral artery, who made an unusually excellent recovery. This report stresses the importance of prompt clinico-imaging diagnosis and prophylactic anticoagulant treatment in such cases.

Slight and short-lasting increase of serum S-100B protein in extra-cranial trauma

OBJECTIVE

Serum S-100B protein is an established biochemical marker of traumatic brain injury. At the same time, the question of extra-cranial S-100B release has been raised. This study evaluates the post-traumatic and post-operative release kinetics of S-100B in 45 trauma victims without head injury.

METHOD

Serum S-100B protein was measured on admission and every 24 hours for 4 consecutive days.

RESULTS

Initial S-100B was slightly increased (median: 0.54 microg L-1) and correlated with the severity of extra-cranial trauma (p = 0.0004, Mann-Whitney test). Both severely (abdominal or chest trauma with or without bone fractures) and mildly (long bone fractures) injured showed a rapid decline of S-100B (< 0.2 microg L-1) around 72 hours post-trauma. Extra-cranial surgery caused a secondary increase of S-100B, especially in the mildly injured group (p = 0.004, Wilcoxon signed rank test).

CONCLUSIONS

Extra-cranial injury results in a mild elevation of serum S-100B protein that declines rapidly (1-3 days after injury).

Treatment of idiopathic head drop (camptocephalia) by deep brain stimulation of the globus pallidus internus

Deep brain stimulation of the globus pallidus internus has been shown to be beneficial in a small number of patients suffering from axial dystonias. However, it has not yet been reported as an effective treatment for the alleviation of idiopathic head drop. The authors describe a 49-year-old woman with idiopathic cervical dystonia (camptocephalia) who was unable to raise her head > 30° when standing or sitting; her symptoms would abate when lying down. This disabling neurological condition was treated successfully with bilateral chronic electrical stimulation of the globus pallidus internus.