Risk Of Permanent Neurological Deficit Research Articles

Impact of reimplantation technique of supra-aortic branches in total arch replacement on stroke rate and survival: results from the ARCH registry.

Our objective was to evaluate the impact of reimplantation techniques of the supra-aortic branches in total arch replacement on the rates of permanent neurological deficit (PND) and survival. We identified patients enrolled in the ARCH registry who underwent total arch replacement between 2000 and 2015 with either en bloc or separate reimplantation of the supra-aortic branches. A total of 3345 patients were included in the present analysis. From this cohort, 686 patients underwent en bloc and 2659 patients had separate reimplantation of the supra-aortic branches. Propensity score analysis identified 461 matched patient pairs. In the matched cohort, there were no differences regarding the mortality rate (15.6% vs 15.7%, P = 0.710) or PND (9.2% vs 12.1%, P = 0.231). Although separate reimplantation of the supra-aortic branches was not associated with an increased mortality rate on multivariable logistic regression, it increased the risk of PND [odds ratio (OR) 1.56, 95% confidence interval (CI) 1.06-2.29; P = 0.023]. Propensity-adjusted regression confirmed these findings and found a similar risk for PND with separate reimplantation of the supra-aortic branches (OR 1.50, 95% CI 1.01-2.23; P = 0.047), although this significance was not found with conditional logistic regression (P = 0.20). No significant differences between survival were seen between the 2 matched cohorts (stratified log rank P = 0.35). Separate reimplantation of the supra-aortic branches in total arch replacement is a significant predictor of stroke in the overall group, although comparable stroke rates were observed in the matched cohort. The current trend towards separate reimplantation of supra-aortic branches may expose certain subgroups of patients to an increased risk of stroke, e.g. those with a high atherosclerotic burden.

The role of embolization before surgery for Spetzler-Ponce Class B and C brain AVMs: a prospective cohort series.

There is uncertainty of the benefit of preoperative embolization for Spetzler-Ponce Class (SPC) B and C arteriovenous malformations of the brain (bAVM). We examined whether or not preoperative embolization reduces the risk of permanent neurological deficits in SPC B and C bAVM surgery. A prospective bAVM database (between1989 and 2015) was analyzed by regression for factors associated with a new permanent neurological deficit arising as a consequence of surgery or preoperative embolization with a modified Rankin Scale (mRS) score >1 at 12 months after surgery (adverse outcome). From a cohort of 785 patients with bAVM, 277 patients with SPC B or C bAVM were planned for treatment by surgery with (N.=67) or without (N.=210) preoperative embolization. There were significant differences (embolization versus no embolization) in: permanent neurological deficits leading to a mRS>1 (45% versus 20%, P<0.01); permanent neurological deficits leading to a mRS>2 (22% versus 8.1%, P=0.04); perioperative transfusion of 2.5 liters of blood or more (31% versus 16%, P<0.01); and, delayed postoperative hemorrhage (19% versus 8.1%, P=0.01). Regression analysis identified the following factors to be associated with increased likelihood of an adverse outcome: infratentorial location (odds ratio 0.441, P=0.045); SPC C bAVM (OR=0.501, P=0.034); earlier rank order of surgery (OR=0.994, P<0.01); and, preoperative embolization (OR=0.313, P<0.01). The use of preoperative embolization does not reduce adverse outcomes in SPC B and C bAVM. The role of embolization in the preoperative management of complex bAVM by surgery deserves further study.

Training residents and fellows in the procedure of diagnostic cervicocerebral angiography: Techniques to avoid complications.

We examine the problems arising when training residents/fellows (RFs) initiate the learning of diagnostic cervicocerebral angiography (DCCA) and describe the steps on how to facilitate the learning process while avoiding complications. The risk of permanent neurological deficit as a result of DCCA ranges from 0.3-0.5%. Factors that correlated with complications include the following: the history of cerebral infarction, infusion of a large amount of contrast medium, a prolonged fluoroscopic time (>80 min) and the efficiency of training received. These findings suggest that the neurological morbidity depends largely upon the technique of catheterization of the patient. In order to reduce the complications arising from the lack of training, a personalised mentorship with a careful supervision of trainees is necessary. To ensure a good patient outcome, a decreased procedural time, awareness of complications at every step of the procedure and their avoidance, as well as the provision of good quality images is necessary. A mentorship program with a close supervision of the RFs is also one of the prerequisites for obtaining a good result.

Awake Craniotomy: First-Year Experiences and Patient Perception

Awake craniotomy for brain lesions in or near eloquent brain regions enables neurosurgeons to assess neurologic functions of patients intraoperatively, reducing the risk of permanent neurologic deficits and increasing the extent of resection. A retrospective review was performed of a consecutive series of patients with awake craniotomies in the first year of their introduction to our tertiary non-university-affiliated neurosurgery department. Operation time, complications, and neurologic outcome were assessed, and patient perception of awake craniotomy was surveyed using a mailed questionnaire. There were 24 awake craniotomies performed in 22 patients for low-grade/high-grade gliomas, cavernomas, and metastases (average 2 cases per month). Mean operation time was 205 minutes. Failure of awake craniotomy because of intraoperative seizures with subsequent postictal impaired testing or limited cooperation occurred in 2 patients. Transient neurologic deficits occurred in 29% of patients; 1 patient sustained a permanent neurologic deficit. Of the 18 patients (82%) who returned the questionnaire, only 2 patients recalled significant fear during surgery. Introducing awake craniotomy to a tertiary non-university-affiliated neurosurgery department is feasible and resulted in reasonable operation times and complication rates and high patient satisfaction.

MNGO-13INCREASED RISK OF PERMANENT NEUROLOGIC DEFICITS FOLLOWING MENINGIOMA RESECTION IN THE ELDERLY

INTRODUCTION: Recent studies have inconsistently identified increased age as a predictor of higher perioperative morbidity and mortality in patients surgically treated for a meningioma. We sought to quantify the occurrence of permanent neurologic deficits after operative treatment of meningiomas and to analyze the association of such deficits with patient age. METHODS: We conducted a retrospective cohort study on 223 patients who underwent primary meningioma resection at our institution between 2001-2013. All postoperative entries in the medical record were reviewed for each patient and all new neurological deficits were recorded. Postoperative deficits were defined as permanent if clinically evident at one-year postoperatively. Temporary neurological deficits, non-neurological complications, and pre-existing neurological deficits were not included in our analysis. Patients were stratified into two groups, young and elderly, based on age at time of operation of less than 60 years and 60 years and above respectively. Pearson's correlation and Fisher's exact test were utilized to examine the association of age with the rate of postoperative neurologic deficits. RESULTS: Average age at time of operation was 55.0 ± 14.5 years. 137 and 86 patients were included in the young and elderly subgroups respectively. Overall, 27 (12%) patients suffered from permanent neurological deficits postoperatively. There was a significant positive correlation between increased patient age and risk of permanent neurologic deficits (r = 0.17, p = 0.012). The risk of a new neurologic deficit was 7.3% in the young subgroup of patients versus 20.0% in the elderly subgroup. The increased risk of permanent neurologic deficits postoperatively was significantly higher in the elderly group (relative risk = 2.7, p = 0.010). CONCLUSIONS: Increased age is associated with a higher risk of permanent postoperative neurologic deficits after meningioma resection. Elderly patients are at increased risk of postoperative deterioration and this should be carefully considered before proposing resection of a meningioma in this patient subgroup.

Spontaneous spinal epidural haematoma

SummarySpontaneous spinal epidural haematoma (SSEH) is a rare clinical condition with unknown aetiology. Prompt diagnosis and treatment are paramount because of the risk of permanent neurological deficits without appropriate intervention. We described a case of a 48-year-old man presenting with complete quadriplegia and hypoesthesia. Magnetic resonance imaging revealed cervical cord compression due to a haematoma posterior to the spinal cord. Surgical decompression and evacuation of the haematoma was performed within 12 hours after admission to the authors' hospital. Both the patient's motor and sensory functions recovered soon after the operation. Early surgical decompression for SSEH with neurologic impairment is therefore recommended for the recovery of this patient and also serves as a relevant reference for orthopaedic clinics.Foundation number: CXZZ20140414170821148.

Primo non nocere or maximum survival in grade 2 gliomas? A medical ethical question.

Maximum safe resection is the "gold standard" in surgical treatment of grade 2 gliomas (G2Gs), aiming to achieve maximal survival benefit with minimal risk of functional deficit. To investigate the attitude of patients and experts towards more extensive surgery with a trade-off between neurological function and survival time. Eight patients and seven experts participated in semi-structured focus group interviews. Both patients and experts accepted the premise of balancing neurological function versus longevity. Some patients would accept an increased risk of permanent neurological deficits in order to obtain a chance of increased survival. There was a significant variance in what constituted "quality of life" both between patients and for the individual patient over time. In important life-changing decisions there is no "one size fits all". We find that it is ethically acceptable to offer more extensive surgery than is possible within the concept of maximal safe surgery as a treatment option, when balancing the principles of beneficence, non-maleficience, autonomy and justice supports the decision. At the same time it must be remembered that even when the patients have made a well-informed decision, some will regret it. In that situation it will be our job as healthcare professionals to support them and help carry some of this burden.

Pediatric awake craniotomy and intra-operative stimulation mapping

The indications for operating on lesions in or near areas of cortical eloquence balance the benefit of resection with the risk of permanent neurological deficit. In adults, awake craniotomy has become a versatile tool in tumor, epilepsy and functional neurosurgery, permitting intra-operative stimulation mapping particularly for language, sensory and motor cortical pathways. This allows for maximal tumor resection with considerable reduction in the risk of post-operative speech and motor deficits. We report our experience of awake craniotomy and cortical stimulation for epilepsy and supratentorial tumors located in and around eloquent areas in a pediatric population (n=10, five females). The presenting symptom was mainly seizures and all children had normal neurological examinations. Neuroimaging showed lesions in the left opercular (n=4) and precentral or peri-sylvian regions (n=6). Three right-sided and seven left-sided awake craniotomies were performed. Two patients had a history of prior craniotomy. All patients had intra-operative mapping for either speech or motor or both using cortical stimulation. The surgical goal for tumor patients was gross total resection, while for all epilepsy procedures, focal cortical resections were completed without any difficulty. None of the patients had permanent post-operative neurologic deficits. The patient with an epileptic focus over the speech area in the left frontal lobe had a mild word finding difficulty post-operatively but this improved progressively. Follow-up ranged from 6 to 27months. Pediatric awake craniotomy with intra-operative mapping is a precise, safe and reliable method allowing for resection of lesions in eloquent areas. Further validations on larger number of patients will be needed to verify the utility of this technique in the pediatric population.

Choroid artery occlusion after treatment of ICA termination aneurysm: was it caused by stent induced vasospasm?

Dear Sirs: Endovascular occlusion has become the main treatment for cerebral aneurysms in the last decade. This development was much facilitated by the ISAT trial [1] for ruptured aneurysms, but coiling, stenting and flow diversion are now also widely used for unruptured cases. While endovascular treatment is usually less invasive than surgical aneurysm clipping, coil occlusion of an aneurysm seems less durable. This has led to the increasing use of stents to reconstruct the vessel wall for the prevention of recurrences. If an elective stent placement is performed under appropriate antiplatelet medication, stentrelated complications such as thrombotic stent occlusion and embolic events are infrequent [2, 3]. We report on a rare complication after placement of a selfexpanding endovascular stent, leading to a disabling stroke in a young patient with an unruptured internal carotid artery (ICA) aneurysm. A 27-year-old female patient, who had delivered a healthy daughter 6 weeks previously, presented to her local hospital with transient left-sided weakness. Vascular risk factors included obesity (BMI=35 kg/m) and smoking. A probable transient ischaemic attack (TIA) was diagnosed, and the patient was investigated accordingly. While no obvious aetiologywas found for the TIA, her brain imaging had shown an incidental lesion, which was suggestive of a left ICA aneurysm with a diameter of around 10 mm. A subsequent CT angiogram (CTA) done at the local neurosciences centre confirmed the presence of a broad-based left ICA termination aneurysm with a maximum diameter of 12 mm, mostly extending on to the left M1 segment, but also slightly affecting the A1. No other aneurysm was seen. Given the size of the aneurysm, the patient was offered endovascular treatment. She was quoted a risk of permanent neurological deficit of 3 % or less. Because of the large neck size, a stent-assisted coil embolisation was planned, and the patient was asked to take 75 mg of aspirin and clopidogrel each starting 5 days before the planned procedure. The patient was admitted on the morning of the intervention and clerked by the clinical team. She confirmed having taken her dual antiplatelet therapy as prescribed. She also stated that she was only smoking occasionally, but her frequent absences from the ward suggested higher nicotine consumption on that morning. The procedure was performed under general anaesthetic (GA). However, bronchospasm and a sudden severe drop in blood saturation levels complicated the induction of the anaesthesia. The patient had no background of respiratory problems, and according to the anaesthetist, heavy smoking prior to the GAwas the most likely explanation. A diagnostic angiogram after intubation confirmed the presence of a large left carotid terminus aneurysm (Fig. 1a). No other abnormalities were seen. The patient received IV heparin under ACT monitoring (>250 s), but platelet function inhibition was not tested. Over an exchange wire, a 6-F 90-cm Terumo Destination sheath was placed into the left proximal ICA, and a Fargomax distal access catheter was advanced into the petrous segment of the ICA. This was complicated by vasospasm at the tip of the long sheath, and therefore, 2 mg of nimodipine was added to the saline flush. W. Kuker (*) Department of Neuroradiology, West Wing, John Radcliffe Hospital, Headley Way, Oxford OX3 9DU, UK e-mail: wilhelm.kuker@ndcn.ox.ac.uk

Surgical Management of Solitary Nerve Sheath Tumors of the Cervical Spine: A Retrospective Case Analysis Based on Tumor Location and Extension

Complete resection of spinal nerve sheath tumors (NSTs) does not always result in significant neurological deficit. The purpose of this retrospective case analysis was to discuss the optimal surgical strategy for spinal NST of the cervical spine. Twenty-four patients who underwent surgery for solitary cervical NST over the past decade were included in this retrospective study. Patients with neurofibromatosis or schwannomatosis were excluded. Seventeen of the 24 cases (70.8%) showed extradural dumbbell extension, most frequently at the C1 or C2 vertebral level. Neurological condition was assessed using the modified McCormick functional schema and sensory pain scale. Total removal of the tumor was achieved in 20 of 24 cases (83.3%). Staged surgery using combined anterior and posterior approaches was applied for 2 of 17 cases with extradural dumbbell extension. Tumor involvement with nerve root fibers critical for upper extremity function (C5–C8) was recognized in 6 of 24 cases (25.0%), with complete resection in all 6 cases. Final assessment of neurological function revealed satisfactory or acceptable recovery in all 6 patients. Spinal NSTs with extradural dumbbell extension are a common condition in the cervical spine. Complete removal of spinal NST of the cervical spine may carry a risk of permanent neurological deficit, but such sequelae appeared to be the exception in the present case analysis. A radical and safe surgical strategy, including staged surgery combining anterior and posterior approaches, should be tailored to the individual case.

Role of intraoperative neurophysiological monitoring during fluorescence-guided resection surgery

Fluorescence-guided resection (FGR) using 5-aminolevulinic acid (5-ALA) exhibits a potential risk of permanent neurological deficits that can be minimized using intraoperative neurophysiological monitoring (IONM). We assessed the role of IONM in FGR surgery in patients harboring tumors in or near eloquent areas. IONM and FGR surgeries were performed on 34 patients (49.8 ± 2.4 years) harbored malignant primary gliomas near eloquent cortical areas or semioval center. Different combinations of neurophysiological techniques were used depending on each patient. Gross total resection (GTR) was achieved in 66.7 % of the patients, mean 90.4 ± 3.7 % without neurological deficits. Resection in four patients was stopped by the occurrence of severe warning criteria despite the presence of fluorescence. Hemispheric transcranial electrical stimulation was safe and confident even in cortical surgery. Notably, a significant percentage of patients exhibited clinical improvement after the surgery. One week after surgery, only one patient worsened, and seven patients improved. At 3 months, 27.8 % of the patients improved, and the other patients maintained a similar status to their pre-surgery condition. Warning common criteria (amplitude reduction and/or latency increase) appeared in 68.2 and 50.0 % of patients during cortical or semioval surgery, respectively, with neither a false-negative nor a false-positive clinical outcome. Although 5-ALA exhibits phototoxicity, VEP did not induce any secondary effects in the visual system, including eyelids. IONM can be helpful during surgery to maximize the tumor resection, meanwhile help to avoid neurological deficits and, therefore, to improve the quality of life of these patients.

Hypofractionated stereotactic radiotherapy for large or involving critical organs cerebral arteriovenous malformations

BackgroundThe treatment of large arteriovenous malformations (AVMs) or AVMs involving eloquent regions of the brain remains a challenge. For inoperable lesions, observation, volume-staged radiosurgery or hypofractionated stereotactic radiotherapy (HFSRT) are proposed. The aim of our study was to assess the safety and efficiency of HFSRT for large AVMs located in eloquent areas of the brain.Materials and methodsAn analysis of records of 49 patients irradiated for cerebral AVMs with a mean dose of 19.9 Gy (12–28 Gy) delivered in 2–4 fractions with planned gap (at least one week) between fractions. Actuarial obliteration rates and annual bleeding hazard were calculated using Kaplan-Meier survival analysis and life tables.ResultsAnnual bleeding hazard rates were 4.5% and 1.6% after one and two years of the follow-up, respectively. Actuarial total obliteration rates were 7%, 11%, and 21% and total response rate (total and partial obliterations) 22%, 41%, and 55% after one, two and three years of the follow-up, respectively. There was a trend towards larger total obliteration rate in patients irradiated with fraction dose ≥ 8 Gy and total dose > 21 Gy for lesions of volume ≤ 8.18 cm3 which was not observed in case of partial obliterations.ConclusionsHFSRT results with relatively low obliteration rate but is not associated with a significant risk of permanent neurological deficits if both total and fraction doses are adjusted to size and location of the lesion. Predictive factors for total and partial obliterations can be different; this observation, however, is not firmly supported and requires further studies.

Vitamin B1 in the treatment of Wernicke’s encephalopathy due to hyperemesis after gastroplasty

Wernicke’s encephalopathy (WE) is a severe brain disorder, first described in 1881, and is caused by a nutritional deficiency of thiamine (vitamin B1) found mostly in patients suffering from chronic alcoholism. In addition, WE can also complicate bariatric surgery if adequate vitamin supplementation is not insured. Without immediate treatment, the prognosis is poor and the mortality rate is high. Most patients present with atypical neurological symptoms, which hampers rapid diagnosis. We present a 40-year-old woman who underwent gastroplasty combined with gastric banding for severe obesity. She experienced repetitive vomiting and her diet was without vitamin supplementation. After three months she developed convergent strabismus, apathy and urinary incontinence, which was diagnosed as WE and treated as such. Six months later her recovery was incomplete, still showing gait difficulties and nystagmus. We aim to show that adequate vitamin supplementation in patients undergoing gastroplasty is necessary, especially considering the risk of permanent neurological deficits.

Aortic arch surgery with a mild-to-moderate circulatory arrest: the significance of aortic arch pathology

We read with great interest the article by Urbanski et al. [1] about aortic arch surgery using a mild-to-moderate hypothermic circulatory arrest. They evaluated a large series of patients who underwent aortic arch surgery in an elective setting. The mean temperature at circulatory arrest was 29.9°C and the mean duration of circulatory arrest was only 18 min. Surgical results were remarkable. Thirty-day mortality was only 0.9%, permanent neurological deficits and temporary neurological deficits were both also 0.9%, respectively, and there was no paraplegia. They showed quite a low incidence of postoperative acute renal failure and respiratory failure. In this series, an acute aortic dissection was excluded and most of the patients’ indication for surgery was degenerative or atherosclerotic disease. Interestingly, 299 (86%) patients had aortic valve disease and 312 (90%) patients underwent concomitant aortic valve surgery, although the reports of other large series showed that only 8% of patients had an aortic root replacement and 3.8% of patients had an aortic valve replacement [2]. Probably, in these authors’ report, many patients had aortic valve stenosis and/or regurgitation with an ascending aortic aneurysm. For this pathology, it is often an aneurysm which extends to the proximal aortic arch; therefore, sometimes a proximal arch replacement is required in addition to aortic valve or root surgery. In this setting, open distal anastomosis is an appropriate procedure to repair the proximal aortic arch. However, compared to a distal aortic arch aneurysm, the atherosclerotic change in the anastomosis site would be mild and the anastomsis technique would not be as complex and time-consuming. For repairing the distal aortic arch aneurysm, the distal anastomosis site could be deep inside the chest cavity and the aortic arch usually has significant atherosclerotic changes. Therefore, selective cerebral perfusion time and circulatory arrest time could be longer than the proximal arch repair and the risk of permanent neurological deficit could be higher. We believe that it is difficult to generalize the authors’ technique and strategy to all kinds of patient pathologies, because patient characteristics are extraordinary in this report.

Low-Threshold Monopolar Motor Mapping for Resection of Primary Motor Cortex Tumors

Microsurgery within eloquent cortex is a controversial approach because of the high risk of permanent neurological deficit. Few data exist showing the relationship between the mapping stimulation intensity required for eliciting a muscle motor evoked potential and the distance to the motor neurons; furthermore, the motor threshold at which no deficit occurs remains to be defined. To evaluate the safety of low threshold motor evoked potential mapping for tumor resection close to the primary motor cortex. Fourteen patients undergoing tumor surgery were included. Motor threshold was defined as the stimulation intensity that elicited motor evoked potentials from target muscles (amplitude > 30 μV). Monopolar high-frequency motor mapping with train-of-5 stimuli (HF-TOF; pulse duration = 500 microseconds; interstimulus interval = 4.0 milliseconds; frequency = 250 Hz) was used to determine motor response--negative sites where incision and dissection could be performed. At sites negative to 3-mA HF-TOF stimulation, the tumor was resected. HF-TOF mapping localized the motor neurons within the precentral gyrus by using variable, low-stimulation intensities. The lowest motor thresholds after final resection ranged from 3 to 6 mA, indicating close proximity of motor neurons. Postoperatively, 12 patients had no new motor deficit, 1 patient had a minor new temporary deficit (M4+, National Institutes of Health Stroke Scale 1), and another patient had a minor new permanent deficit (M4+, National Institutes of Health Stroke Scale 2). Thirteen patients had complete or gross total resection. These preliminary data demonstrate that a monopolar HF-TOF threshold > 3 mA was not associated with a significant new motor deficit.

HydroCoils, Occlusion Rates, and Outcomes: A Large Single-Center Study

The HydroCoil is an expansile hydrogel coil designed to produce a greater degree of volumetric packing within cerebral aneurysms when compared with bare platinum coils. This increased packing is, in turn, believed to decrease the risk of recurrence within aneurysms and hence the risk of their rupture in the long term. The aim of this work was to assess whether the use of HydroCoils and the proportion of HydroCoil used have any influence on the subsequent occlusion and recurrence rates of treated aneurysms. A retrospective study was performed of 328 patients during 5 years at a single institution. The initial angiographic and follow-up angiographic occlusion rates were recorded as were any procedural complications. The proportion of HydroCoil used was described as the relative amount of HydroCoil length to the total coil length used during an aneurysm treatment, thus forming 4 groups: 0%-19%, 20%-49%, 50%-69%, 70%-100%, and the subgroups with 100%. Two hundred seventy patients had angiographic follow-up during an average of 13 months. The overall risk of permanent neurologic deficit and death was 3%. The rate of complete occlusion was 31% immediately postcoiling and 64.8% on follow-up. At the latest follow-up, 25.6% had residual necks and 9.6% had residual aneurysms. There was a statistically significant trend for HydroCoils to produce greater occlusion rates on follow-up when >70% HydroCoil was used (P = .025). The overall rate of recurrence for all aneurysms as a group was 15.5%. The retreatment rate was 6.6%. There has been 1 rebleed in the 328 patients. The overall results following the use of HydroCoils to occlude aneurysms compare well with those in other reported series. HydroCoils do produce a statistically significantly greater rate of occlusion when >70% of total aneurysm coil length is HydroCoil compared with coiling with <20% HydroCoil. There was no significant difference, however, in the recurrence or retreatment rate when comparing these groups.

Epidural Hematoma Nine Days After Removal of a Labor Epidural Catheter

Timely recognition and surgical decompression are crucial to minimize risk of permanent neurologic deficit from epidural hematoma. We present the case of a patient who developed acute back pain, sensory deficit, and ascending weakness 9 days after removal of a labor epidural catheter. Magnetic resonance imaging revealed a heterogeneous fluid collection extending from C6-7 through the lumbar region, with cord deformity at T9-11. Decompression laminectomy was performed within 4 hours of symptom onset. Twelve hours later, her motor function had fully recovered. Subsequent anatomic and hematologic workup was inconclusive. This presentation is atypical given the delayed presentation of symptoms after epidural placement.

Single-port endoscopic removal of intraventricular central neurocytoma

Central neurocytoma is a rare benign intraventricular tumor which occurs in young adults. Craniotomy with tumor removal is associated with relatively high rates of morbidity and mortality. To improve the efficiency of endoscopic surgery for removal of this tumor, we used a polypropylene tube combined with a working channel endoscope. From January 2006 to October 2008, three patients with intraventricular central neurocytoma with acute hydrocephalus were treated by endoscopic surgery in our hospital. The tumor was almost totally removed. At 6-month follow-up no recurrence was found. One patient required a permanent ventriculoperitoneal shunt due to hydrocephalus during follow-up. We report that a working channel endoscope combined with a polypropylene endoscopic sheath facilitates the removal of intraventricular central neurocytoma. Endoscopic neurosurgery is a safe method for removing a central neurocytoma with low risk of permanent neurological deficits.

Intraoperative use of somatosensory-evoked potentials: is general anaesthesia comparable to awake condition?

Editor, We have read with great interest the article by Fielmuth and Uhlig [1] on the role of somatosensory-evoked potentials (SSEPs) in detecting cerebral ischaemia during carotid endarterectomy. The authors made an assessment of the validity of SSEP monitoring during carotid endarterectomy in awake patients under locoregional anaesthesia. They correctly reported the current substantial variety of SSEP parameters and thresholds related to these SSEP parameters used to detect critical deterioration in cerebral blood flow (CBF). Their study was designed to compare SSEP tracings with the objective clinical–neurological examination in order to evaluate the reliability of the different SSEP-generated criteria. They referred to Shapiro and Aidinis [2], who developed a model, which can be seen as the methodological basis for current neuromonitoring during carotid surgery. This model correlates neuronal integrity and electrical activity with CBF. Using this approach to interpret changes in SSEP tracing as a perfusion-dependent neuronal metabolic situation, different parameters and values have been established to detect a relevant reduction in CBF.

TUMORS OF THE LATERAL AND THIRD VENTRICLE

Intraventricular tumors usually are managed by approaches and microsurgical techniques that need retraction and dissection of important brain structures. Minimally invasive endoscopic procedures achieve a remarkable alternative to conventional microneurosurgical techniques. Endoscope-assisted microneurosurgery may be a minimally invasive technique with maximally effective treatment. Using the keyhole concept for planning the surgical strategy, the reduction of the brain retraction is achieved, which is one of the main benefits of this technique. We treated 35 patients (16 female patients and 19 male patients) with tumors in the lateral (n = 8) and the third (n = 27) ventricle. Patient age at the date of surgery ranged from 5 to 73 years. The follow-up period ranged from 6 to 83 months. The tumors were operated on using transcortical, transcallosal, or suboccipital transtentorial or infratentorial supracerebellar approaches after precise planning of the skin incision, the trephination, and the trajectory to the center of the tumor, performed earlier with a magnetic resonance imaging scan. Total removal of the tumor was achieved in 28 patients (78.5%). In 2 patients (6.5%), recurrent tumor occurred. In 5 patients (15%), parts of the tumors remained because of infiltration of eloquent areas. Overall clinical improvement was achieved in 31 patients (87%). Three patients (10%) were unchanged and 1 patient (3%) deteriorated. Endoscope-assisted keyhole neurosurgery seems to be a safe method of removing tumors in all regions inside the ventricular system with a low risk of permanent neurological deficits. The exact surgical corridor planning on the basis of the keyhole strategy offers less traumatic exposure of even deep-seated endoventricular tumors.