Are Dynamic Arterial Spin-Labeling MRA and Time-Resolved Contrast-Enhanced MRA Suited for Confirmation of Obliteration following Gamma Knife Radiosurgery of Brain Arteriovenous Malformations?

BACKGROUND AND PURPOSE

Intra-arterial DSA has been traditionally used for confirmation of cure following gamma knife radiosurgery for AVMs. Our aim was to evaluate whether 4D arterial spin-labeling MRA and contrast-enhanced time-resolved MRA in combination can be an alternative to DSA for confirmation of AVM obliteration following gamma knife radiosurgery.

MATERIALS AND METHODS

In this prospective study, 30 patients undergoing DSA for confirmation of obliteration following gamma knife radiosurgery for AVMs (criterion standard) also underwent MRA, including arterial spin-labeling MRA and contrast-enhanced time-resolved MRA. One dataset was technically unsatisfactory, and the case was excluded. The DSA and MRA datasets of 29 patients were independently and blindly evaluated by 2 observers regarding the presence/absence of residual AVMs.

RESULTS

The mean time between gamma knife radiosurgery and follow-up DSA/MRA was 53 months (95% CI, 42-64 months; range, 22-168 months). MRA total scanning time was 9 minutes and 17 seconds. Residual AVMs were detected on DSA in 9 subjects (obliteration rate = 69%). All residual AVMs were detected on at least 1 MRA sequence. Arterial spin-labeling MRA and contrast-enhanced time-resolved MRA showed excellent specificity and positive predictive values individually (100%). However, their sensitivity and negative predictive values were suboptimal due to 1 false-negative with arterial spin-labeling MRA and 2 with contrast-enhanced time-resolved MRA (sensitivity = 88% and 77%, negative predictive values = 95% and 90%, respectively). Both sensitivity and negative predictive values increased to 100% if a composite assessment of both MRA sequences was performed. Diagnostic accuracy (receiver operating characteristic) and agreement (κ) are maximized using arterial spin-labeling MRA and contrast-enhanced time-resolved MRA in combination (area under receiver operating characteristic curve = 1, P < .001; κ = 1, P < .001, respectively).

CONCLUSIONS

Combining arterial spin-labeling MRA with contrast-enhanced time-resolved MRA holds promise as an alternative to DSA for confirmation of obliteration following gamma knife radiosurgery for brain AVMs, having provided 100% sensitivity and specificity in the study. Their combined use also enables reliable characterization of residual lesions.

Implementation of duty of candour within neurosurgery: a national survey and framework for improved application in clinical practice

INTRODUCTION

Statutory duty of candour was introduced in November 2014 for NHS bodies in England. Contained within the regulation were definitions regarding the threshold for what constitutes a notifiable patient safety incident. However, it can be difficult to determine when the process should be implemented. The aim of this survey was to evaluate the interpretation of these definitions by British neurosurgeons.

MATERIALS AND METHODS

All full (consultant) members of the Society of British Neurological Surgeons were electronically invited to participate in an online survey. Surgeons were presented with 15 cases and asked to decide in the case of each one whether they would trigger the process of duty of candour. Cases were stratified according to their likelihood and severity.

RESULTS

In all, 106/357 (29.7%) members participated in the survey. Responses varied widely, with almost no members triggering the process of duty of candour in cases where adverse events were common (greater than 10% likelihood) and required only outpatient follow-up (7/106; 6.6%), and almost all members doing so in cases where adverse events were rare (less than 0.1% likelihood) and resulted in death (102/106; 96.2%). However, there was clear equipoise in triggering the process of duty of candour in cases where adverse events were uncommon (0.1-10% likelihood) and resulted in moderate harm (38/106; 35.8%), severe harm (57/106; 53.8%) or death (49/106; 46.2%).

CONCLUSION

There is considerable nationwide variation in the interpretation of definitions regarding the threshold for duty of candour. To this end, we propose a framework for the improved application of duty of candour in clinical practice.

FP1-2 Implementation of duty of candor regulation within neurosurgery: a national cross-sectional survey

Objectives

Statutory Duty of Candor was introduced in 2014 for NHS bodies in England. Contained within the regulation were definitions regarding the threshold for what constitutes a notifiable patient safety incident. The aim of this survey was to evaluate the interpretation of these definitions by British neurosurgeons.

Methods

Full members of the SBNS were electronically invited to participate in an online survey. Surgeons were presented with 15 cases and asked to decide in each one whether they would trigger the process of Duty of Candor. Cases were stratified according to their likelihood and severity.

Results

In all, 106/357 (29.7%) members participated in the survey. Responses varied widely with almost no members triggering the process of Duty of Candor in cases where adverse events were likely (>10% likelihood) and required only outpatient follow up (7/106; 6.6%), and almost all members doing so in cases where adverse events were rare (<0.1% likelihood) and resulted in death (102/106; 96.2%). However, there was clear equipoise in triggering the process of Duty of Candor in cases where adverse events were unlikely (0.1%–10% likelihood) and resulted in moderate harm (38/106; 35.8%), severe harm (57/106; 53.8%), or death (49/106; 46.2%).

Conclusions

There is considerable nationwide variation in the interpretation of definitions regarding the threshold for Duty of Candor; this has important implications with some providers at risk of penalties, and others unduly burdened by the associated administrative processes.

TM1-3 Improved prediction of surgical resectability in patients with glioblastoma multiforme using an artificial neural network

Objectives

In managing a patient with glioblastoma multiforme (GBM), a surgeon must weigh up whether sufficient tumour can be removed so that the patient can enjoy the benefits of decompression and cytoreduction, without impacting on the patient’s neurological status. In a previous study we identified the five most important anatomical features on a pre-operative MRI that are predictive of surgical resectability and used them to develop a grading system. The aim of this study was to apply an artificial neural network (ANN) to improve the prediction of surgical resectability.

Methods

A prospectively maintained database was searched between February and August 2017 to identify all adult patients with supratentorial GBM that underwent resection. Pre-operative MRI scans were scored using the aforementioned grading system and post-operative scans assessed to determine the extent of resection. Performance of the standard grading system and ANN were then evaluated by analysing their Receiver Operator Characteristic curves; Area Under Curve (AUC) and accuracy were calculated and compared using the t-­test with a value of p<0.05 considered significant.

Results

In all, 47 patients were included, of which 18 (38.3%) were found to have complete excision. The AUC and accuracy were significantly greater using the ANN compared to the standard grading system (0.87 vs. 0.79 and 0.81 vs. 0.77 respectively; p<0.01 in both cases).

Conclusions

An ANN allows for improved prediction of surgical resectability in patients with GBM.

WP1-15 Computer-assisted versus manual planning for stereotactic brain biopsy: retrospective comparative pilot study

Objectives

Stereotactic brain biopsy is among the most common neurosurgical procedures. Planning a safe surgical trajectory requires careful attention to a number of features including:

traversing the skull perpendicularly;

avoiding critical neurovascular structures; and

minimising trajectory length.

The aim of this study was to develop a platform, SurgiNav, for automated trajectory planning in stereotactic brain biopsy.

Methods

A prospectively maintained database was searched between February and August 2017 to identify all adult patients that underwent stereotactic brain biopsy in whom post-operative imaging was available. In each case, the standard pre-operative T1-weighted gadolinium-enhanced MRI was used to generate models of the cortex and vasculature. A surgical trajectory was then generated using automated computer-assisted planning (CAP) and metrics compared to the trajectory of the implemented manual plan (MP) using the paired T-test.

Results

15 consecutive patients were identified; who had a diagnostic biopsy and there were no immediate complications. Feasible trajectories were generated using CAP in 12 patients, and in these the mean trajectory length using CAP was comparable to MP (31.7 mm vs. 37.1 mm; p=0.3), and mean angle was similarly perpendicular from orthogonal (9.3° vs. 15.3° p=0.1), but the risk-metric was significantly lower (0.16 vs. 0.48; p=0.03).

Conclusions

Computer-assisted planning for stereotactic brain biopsy appears feasible in most cases and may be safer in selected cases.

The longitudinal profile of bilirubin and ferritin in the cerebrospinal fluid following a subarachnoid hemorrhage: diagnostic implications

BACKGROUND

Cerebrospinal fluid (CSF) spectrophotometry for bilirubin is a highly sensitive test in the diagnostic work up of a suspected subarachnoid hemorrhage (SAH).

CASES

We report two cases suffering from an aneurysmal SAH in which extraventricular drainage for acute hydrocephalus was required. Longitudinal analyses of the CSF samples demonstrated that CSF bilirubin was detectable in all cases during the first week, becoming undetectable in one case in the second week. Importantly, CSF ferritin levels rose substantially (>1,000 ng/ml) after 6 days, peaking around 3,000 ng/ml after 2 weeks (normal upper reference range 12 ng/ml). In both cases blood was visible on the initial CT brain scan, disappearing on a later scan.

CONCLUSION

CSF ferritin levels may be an important additional laboratory test in the diagnostic work-up of patients with a suspected SAH. CSF ferritin levels may prove particularly helpful in cases with late presentation if the CT brain scan is normal and CSF bilirubin level is undetectable.

Free phenytoin concentration measurement in brain extracellular fluid: a pilot study

This article investigates the relationship between brain extracellular fluid free phenytoin concentration and plasma free phenytoin concentration in adults with acute brain injury. Daily cerebral microdialysate free phenytoin concentration was measured in eight adults with acute brain injury and compared with simultaneous measurement of plasma free phenytoin concentration. The group data revealed no significant correlation between microdialysate and plasma free phenytoin concentration (r = 0.34, p = 0.41). However, in two patients, with a sufficient number of samples for intra-individual analysis, there was a significant correlation between microdialysate and plasma free phenytoin concentration (r = 0.92, p < 0.001 and r = 0.88, p < 0.01). In vitro microdialysis relative recovery for phenytoin was 2.1%. In the context of acute brain injury, measurement of free plasma phenytoin concentration may not provide an accurate reflection of regional brain extracellular fluid free phenytoin concentration and may have limitations with respect to achieving reproducible brain extracellular fluid free phenytoin concentrations. This has implications for dosing regimens relying on plasma phenytoin levels.

Improving the recovery of S100B protein in cerebral microdialysis: implications for multimodal monitoring in neurocritical care

INTRODUCTION

Cerebral microdialysis is an established research tool that is used by an increasing number of neurocritical care units as a component of bedside multimodality monitoring. Body fluid biomarkers are an emerging tool for the assessment of brain injury. The correct interpretation of body fluid biomarker levels depends on the degree of recovery, i.e. relative recovery and the accuracy of the analytical technique.

METHODS

In vitro recovery experiments were performed on 100mL volumes of cerebrospinal fluid and solutions of S100B, glucose, lactate and pyruvate comparing relative recoveries using commercially available 20 kDa (CMA70) and 100 kDa (CMA71) microdialysis catheters. We also compared the CMA 600 microdialysis analyzer with a YSI 2003 STAT Plus analyzer for glucose and lactate to determine its reliability.

RESULTS

Significantly, we demonstrate the improved recovery of the protein S100B using a larger molecular weight (MW) cut-off catheter (20 kDa range: 0.1-9%; 100 kDa range: 1.7-18.3%) while maintaining comparable performance for the conventional markers glucose, lactate and pyruvate. Additionally we found that the CMA 600 analyzer may be prone to overestimation of lactate readings at higher concentration with implications for clinical decision-making.

CONCLUSION

Our data demonstrates that the 100 kDa MW cut-off catheter allows for the improved recovery of macromolecules in cerebral microdialysis research while maintaining the value of existing MD data for routine clinical use.

Metabolic failure precedes intracranial pressure rises in traumatic brain injury: a microdialysis study

BACKGROUND

Cerebral microdialysis (MD) is able to detect markers of tissue damage and cerebral ischaemia and can be used to monitor the biochemical changes subsequent to head injury. In this prospective, observational study we analysed the correlation between microdialysis markers of metabolic impairment and intracranial pressure (ICP) and investigated whether changes in biomarker concentration precede rises in ICP.

METHODS

MD and ICP monitoring was carried out in twenty-five patients with severe TBI in Neurointensive care. MD samples were analysed hourly for lactate:pyruvate (LP) ratio, glutamate and glycerol. Abnormal values of microdialysis variables in presence of normal ICP were used to calculate the risk of intracranial hypertension developing within the next 3 h.

FINDINGS

An LP ratio >25 and glycerol >100 micromol/L, but not glutamate >12 micromol/L, were associated with significantly higher risk of imminent intracranial hypertension (odds ratio: 9.8, CI 5.8-16.1; 2.2, CI 1.6-3.8; 1.7, CI 0.6-3, respectively). An abnormal LP ratio could predict an ICP rise above normal levels in 89% of cases, whereas glycerol and glutamate had a poorer predictive value.

CONCLUSIONS

Changes in the compound concentrations in microdialysate are a useful tool to describe molecular events triggered by TBI. These changes can occur before the onset of intracranial hypertension, suggesting that biochemical impairment can be present before low cerebral perfusion pressure is detectable. This early warning could be exploited to expand the window for therapeutic intervention.

The interleukin-6 gene -174G>C and -572G>C promoter polymorphisms are related to cerebral aneurysms

BACKGROUND AND AIMS

An important part is played by inflammation in intracranial aneurysm formation. The hypothesis that there is an association of the proinflammatory cytokine interleukin-6 (IL-6) genotypes (-572G>C and -174G>C) with intracranial aneurysms was tested.

METHODS

IL-6 genotypes were determined in 91 Caucasian patients with aneurysms and compared with 2720 healthy UK controls.

RESULTS

For both polymorphisms, the distribution of the genotypes and estimated allele frequency were different between the control group and the aneurysm group. For -572G>C, a higher frequency of the C allele (p = 0.001) and more people homozygous for the C allele were found among those with aneurysms than among the controls (4.4% v 0.3%, p = 0.001). For -174G>C, more people homozygous for the C allele were found among the controls than among those with aneurysm (18% v 7%, p = 0.007). The 572C/174G haplotype was associated with an increased risk of aneurysms, with the relative risk compared with the common haplotype being 1.89 and that for the -572G/174C haplotype being 0.58 (p<0.0005).

CONCLUSION

This is the first study to show that IL-6 promoter polymorphisms are associated with intracranial aneurysmal disease. Whether this association is with the development, progression or rupture of such aneurysms, or represents survivor bias, is unclear.

Polymorphism of the heme oxygenase-1 gene and cerebral aneurysms

Inflammation is thought to play an important role in intracranial aneurysm formation. Heme-oxygenase-1(HO-1) is a novel anti-inflammatory factor. A length polymorphic variant of the HO-1 gene promoter region, comprising (GT)n dinucleotide repeats, is associated with altered levels of gene transcription: long (= 36 GT) repeats are associated with decreased HO-1. We hypothesized that patients with aneurysmal subarachnoid haemorrhage were more likely to have long repeats than controls. Sixty-nine patients with aneurysms and 230 age-matched controls were genotyped, and allelic repeats were classed as <36 (short and medium repeats) and >36 (long repeats). Patients were more likely to have =36 repeats than controls (8 v. 4%, p = 0.037. Control patients without aneurysms were more likely to have short alleles. Thus, facilitated up-regulation of HO-1 may be a protective anti-inflammatory factor against the development of intracranial aneurysms, whilst a propensity to a more pro-inflammatory state may put individuals at risk. However, because of the relatively small sample size and modest statistical significance, the data must be interpreted with caution and the association needs to be confirmed in further samples.

Extracellular fluid S100B in the injured brain: a future surrogate marker of acute brain injury?

The authors describe the measurement of S100B protein in brain extracellular fluid (ECF) of patients with acute brain injury (traumatic brain injury and subarachnoid haemorrhage) using the technique of microdialysis. To our knowledge, this is the first report of S100B measurement in the human brain. Acute Brain Injury (ABI) is a leading cause of death and disability and the need for a practical and sensitive biochemical marker for monitoring these patients is urgent. The calcium binding astrocyte protein, S100B, may be a candidate for this role. Previous serum studies have shown S100B to be a sensitive predictor of mortality and rise in intracranial pressure in ABI, but it has never before been measured directly within the brain. The ECF reflects the local biochemistry of the brain parenchyma, and the use of intracerebral microdialysis opens up the possibility of studying many novel surrogate markers of injury in the laboratory, in addition to the conventional markers it measures at the bedside (lactate, pyruvate, glucose, and glycerol). In this preliminary report of two cases, the authors demonstrate the quantification of S100B in ECF microdialysate, and investigate whether changes in hourly S100B profile can be related to secondary brain injury. It is shown that extracellular concentrations of S100B change markedly in response to secondary brain injury. Further investigation is required to determine whether extracellular S100B measurement in ABI could assist in patient management.

Axonal pathology in subarachnoid and intracerebral hemorrhage

Electrically active axons degenerate in the presence of nitric oxide (NO) in vitro. High CSF NO concentrations have been observed in patients with hemorrhagic brain injury such as subarachnoid hemorrhage (SAH) and intracerebral hemorrhage (ICH). This study investigated the evidence for axonal injury in SAH and ICH and related this to CSF NO levels. In this study, neurofilament phosphoforms (NfH(SMI34), NfH(SMI35), NfH(SMI38), NfH(SMI310)), surrogate markers for axonal injury, and NO metabolites (nitrate, nitrite = NOx) were measured by ELISA in cerebrospinal fluid (CSF) from patients with SAH and ICH and from a group of controls. Injury severity was classified using the Glasgow Coma Scale, and survival was used as the outcome measure. Compared to the control group, a higher proportion of patients with SAH and ICH had elevated NfH(SMI34) levels from day 0 to day 6 (p < 0.001), elevated NfH(SMI35) levels from day 1 to 6 (p < 0.001), and elevated NfH(SMI310) levels at day 0, 1, 4, and 6 (p < 0.001). The NOx levels were higher in the SAH and ICH patients than in the controls (p < 0.05) and distinguished the non-survivors from the survivors (p < 0.05). No direct correlation was found for NOx with any of the NfH phosphoforms. This study provides evidence for primary and secondary axonal injury in patients with SAH and ICH, with non-survivors also having higher NOx levels. CSF NfH phosphoforms might emerge as a putative surrogate marker for monitoring the development for secondary axonal degeneration in neurocritical care and guiding targeted neuroprotective strategies.

Psychosocial outcomes at 18 months after good neurological recovery from aneurysmal subarachnoid haemorrhage

OBJECTIVES

To evaluate functioning, 18 months after surgery, of 49 patients with good neurological recovery following aneurysmal subarachnoid haemorrhage (SAH), and to determine the extent of any improvements in disturbances of mood, cognitive functioning, and levels of activity and participation previously observed at 9 month follow up.

METHODS

SAH patients, matched for age, gender, and occupation with healthy control participants, completely quantitative measures of mood (HADS, FIES, BDI) and activity/participation (BICRO-39 scales), and a brief cognitive assessment battery (verbal fluency, digit span, prose recall). Controls completed the HADS and the BICRO-39.

RESULTS

Patients showed some recovery of cognitive functioning, though impairments of prose recall persisted. Anxiety and depression symptoms were higher in patients than in controls, but fewer than 20% scored in the clinical range on any questionnaires except for RIES-Intrusive thoughts (22%); only three showed signs of full blown post-traumatic stress disorder. Almost half showed elevated dependence on others for domestic activities and organisation and abnormally low levels of employment. Very little variance in outcome was predicted by demographic variables, neurological or cognitive impairment, prior life stress, or mood. However, levels of social activity and self-organisation were related to persisting fatigue.

CONCLUSIONS

The observed decline in intrusive thoughts and avoidance over time is consistent with that seen after life threatening illness or trauma. The persistent reductions in independence and levels of employment may in some cases reflect considered lifestyle adjustments rather than adverse and unwanted changes but in others indicate a need for focused rehabilitation.

Trigeminal neuralgia presenting as Chiari I malformation

Chiari I malformation usually presents with headache, numbness, weakness and gait abnormalities. We present a 38-year-old female with trigeminal neuralgia who was found to have a Chiari I malformation. She had a foramen magnum decompression with complete resolution of her symptoms.

Role of serum S100B as an early predictor of high intracranial pressure and mortality in brain injury: a pilot study

OBJECTIVE

To investigate whether serum S100B is suitable as a sensitive biomarker for early prediction of increased intracranial pressure and mortality rates after brain injury.

DESIGN

A prospective, longitudinal study.

SETTING

Neurosurgical intensive care unit.

PATIENTS

Twenty-one patients with acute brain injury and 13 healthy controls.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We assessed Glasgow Coma Scale score and pupil reaction on admission and quantified serum S100B (in-house enzyme-linked immunosorbent assay) and intracranial pressure on admission and the subsequent 6 days. Serum S100B concentrations on admission and day 1 were significantly higher in patients with fatal outcome (p <.05, p<.01, respectively), with a sensitivity of 100% and a specificity of 75-83%. Patients with high serum S100B on admission had an eight-fold and on day 1 a 12-fold increased relative risk of a fatal outcome. Subsequent serum S100B values predicted the development of high intracranial pressure in patients with traumatic brain injury (p <.01). Patients with high intracranial pressure on day 5 had an 11-fold and on day 6 a nine-fold increased risk of fatal outcome.

CONCLUSIONS

Serum S100B is a sensitive biomarker for early prediction of the development of high intracranial pressure and fatal outcome following acute brain injury. Monitoring S100B concentrations could contribute to early detection of patients at risk of secondary increases in intracranial pressure and subsequent mortality. This would allow earlier targeting of therapy in selected patients.

Psychosocial outcomes at three and nine months after good neurological recovery from aneurysmal subarachnoid haemorrhage: predictors and prognosis

OBJECTIVES

To investigate (1) the prevalence of various aspects of cognitive and psychosocial dysfunction, including post-traumatic stress symptoms, over nine months after subarachnoid haemorrhage (SAH); (2) whether SAH is preceded by increased life stress; (3) to what extent adverse outcomes may be predicted from preillness life stress, early neurological impairment, age, and sex; and (4) relations between emotional and functional outcomes.

METHODS

52 patients with good neurological recovery after surgery for SAH were each matched for age, sex, and occupation with a healthy control participant. SAH patients were assessed three and nine months postdischarge on measures of cognitive functioning, mood, and social functioning. Objective stressors and subjective life change during the preceding year were rated retrospectively. Controls completed measures of mood and social functioning once only.

RESULTS

Compared with controls, SAH patients showed increased mood disturbance, subtle cognitive impairment, and abnormally low independence and participation on measures of social functioning. 60% showed clinically significant post-traumatic stress symptomatology (intrusive thoughts or avoidance of reminders) at three months and 30% at nine months. Independence in activities of daily living was greatly reduced in half to a third of the sample at both three and nine months. Productive employment was below the 10th percentile of the control group for 75% of patients at three months and for 56% at nine months; this outcome could not be predicted from selected demographic, premorbid, or clinical variables but dependence on others for organisational activities was predicted by impaired prose recall. Mood at nine months was strongly predicted by prior mental health problems, poor physical health, dysphasia, and impaired prose recall at three months. There was no evidence of an abnormally high level of stressful life events in the year before SAH, although patients rated their subjective level of stress in this period slightly more highly than did the control participants.

CONCLUSIONS

These findings highlight the need for structured support and treatment after surgery for SAH to reduce persisting mood disturbance and increase independence and participation.

Primary malignant melanoma of the cerebellopontine angle

BACKGROUND

Malignant tumors of the cerebellopontine angle are very rare, accounting for less than 1% of lesions at this site. These may be primary or secondary tumors of the temporal bone, central nervous system (CNS), or leptomeninges. Malignant melanoma is uncommon, accounting for 1.5% of all types of malignant tumors. Metastatic melanoma is a frequent cause of CNS metastasis, often with leptomeningeal spread. Primary leptomeningeal melanoma is, however, rare and even more so at the cerebellopontine angle. The prognosis for CNS malignant melanoma is generally very poor.

PATIENT

The authors describe the case of a 29-year-old woman with unilateral hearing loss and facial paresis. Magnetic resonance imaging (MRI) demonstrated a mass that was thought to be an acoustic neuroma but was seen to involve the cochlea as well as the internal auditory meatus and cerebellopontine angle. The lesion was subsequently excised completely by a trans-labyrinthine approach, with facial nerve preservation, and was shown on histologic examination to be a malignant melanoma. Further comprehensive investigation did not reveal a primary extracranial site or any sign of CNS spread. The clinical features of this case, including the radiologic and histologic findings, are described, and literature concerning management is reviewed.

Phase I clinical trial of the chimeric monoclonal antibody (c30.6) in patients with metastatic colorectal cancer

The murine antibody 30.6 recognizes an antigen that is expressed on a high proportion of colorectal carcinomas and their metastases. We report the results of single-dose escalation studies of the chimeric 30.6 (c30.6) monoclonal antibody in metastatic colorectal cancer, to evaluate its safety, pharmacokinetics, and biodistribution. Recombinant c30.6 (IgG1kappa) antibody was secreted from Chinese hamster ovary cells and purified by a multistep chromatography process. Seventeen patients with metastatic colorectal cancer were enrolled in this dose escalation study. The first four patients were treated with 3 mg of 123I-labeled c30.6, whereas the next 13 received a single dose of unlabeled antibody (maximum dose, 50 mg/m2). The most frequent side effect was a novel syndrome of severe burning and erythema of the face, chest, neck, ears, palms, soles, and genitalia. The frequency of this syndrome was markedly reduced in those patients premedicated with high doses of histamine receptor 1 and histamine receptor 2 blockers. Other side effects were mild and predictable. Biodistribution studies showed a rapid and intensive hepatic uptake. At the 50 mg/m2 level the half-life and maximum serum concentration were 81 +/- 15 h and 7.9 microg/ml, respectively. One patient developed a low-level human anti-c30.6 response. Tumor response was assessed by computed tomography, positron emission tomography scanning, and serial carcinoembryonic antigen measurements. There were no partial responses, although positron emission tomography scanning demonstrated some reduction in tumor activity in three individuals. The chimerized c30.6 antibody is not immunogenic in humans and appears worthy of further study. It does, however, produce a unique profile of side effects that can be well controlled with premedication.

Surgical treatment of epilepsy resistant to medical therapy

Epilepsy is a chronic brain disorder characterized by the spontaneous occurrence of seizures, the clinical characteristics of which depend on the regions of the brain involved at the beginning of, during and after the ictal event. The prevalence of epilepsy in UK ranges between 0.5 and 1% and of these about 20% are considered to be refractory to pharmacotherapy.

Contrast-enhanced MR angiography in patients with carotid artery stenosis: comparison of two different techniques with an unenhanced 2D time-of-flight sequence

Conventional time-of-flight (TOF) MR angiography (MRA) in carotid artery stenosis relies on flow-related enhancement to produce signal from vascular structures. Intravoxel phase dispersion, due to vortices, causes loss of signal and is the reason for the tendency to overestimate the degree of stenosis. In contrast-enhanced MRA, intravascular signal is mainly dependent on T1 shortening of the blood. We compared first-pass contrast-enhanced MRA (contrast-enhanced 3D gradient echo, ce3D GRE) and contrast-enhanced 2D TOF (ce2D TOF) sequences with an unenhanced 2D TOF in 13 patients with carotid artery stenosis, assessing delineation of the carotid bifurcation, enhancement of veins and grade of stenosis. The contrast-enhanced techniques produced more morphological detail, the ce3D GRE being superior to the ce2D TOF. Four carotid arteries were reclassified into lesser stenosis categories using the ce3D GRE technique. However, seven carotid arteries (27%) were rated as nondiagnostic on the ce3D GRE, mainly due to masking of the carotid bifurcation by veins. The latter can be avoided by decreasing the acquisition time; on our 1.5-T system we could achieve a minimum time of 23 s per 3D GRE. Further reduction of acquisition time would be necessary to incorporate this method into clinical routine, requiring higher-performance gradients, which are not available in many UK hospitals.

Unruptured cerebral aneurysms causing seizure disorder (report of two cases)

Seizures as a presenting feature of unruptured cerebral aneurysm are unusual. We report two cases of unruptured cerebral aneurysm presented with seizures. In both cases the seizures controlled following surgical ablation of the aneurysm.

Pre-operative planning and intra-operative guidance in modern neurosurgery: a review of 300 cases

Operative neurosurgery has recently entered an exciting era of image guided surgery or neuronavigation and application of this novel technology is beginning to have a significant impact in many ways in a variety of intracranial procedures. In order to fully assess the advantages of image guided techniques over conventional planning and surgery in selected cases, detailed prospective evaluation has been carried out during the advanced development of an optically tracked neuronavigation system. Over a 2-year period, 300 operative neurosurgical procedures have been performed with the assistance of interactive image guidance, as well as the development of new software applications and hardware tools. A broad range of intracranial neurosurgical procedures were seen to benefit from image guidance, including 163 craniotomies, 53 interactive stereotactic biopsies, 7 tracked neuroendoscopies and 37 complex skull base procedures. The most common pathological diagnoses were cerebral glioma in 98 cases, meningioma in 64 and metastasis in 23. Detailed analysis of a battery of postoperative questions revealed benefits in operative planning, appreciation of anatomy, lesion location, safety of surgery and greatly enhanced surgical confidence. The authors believe that image guided surgical technology, with new developments such as those described, has a significant role to play in contemporary neurosurgery and its widespread adoption in practice will be realised in the near future.

Supratentorial cavernous haemangiomas and epilepsy: a review of the literature and case series

OBJECTIVES

To characterise the clinical features and response to treatment of supratentorial cavernomas associated with epilepsy.

METHODS

A systematic review of the literature was carried out and a retrospective case series of patients with cavernoma diagnosed by MRI and/or histology was compiled. Patient selection biases in the literature review were reduced as far as possible by selection of unbiased publications.

RESULTS

In the literature, cavernomas were relatively less common in the frontal lobes. There were multiple cavernomas in 23% of cases. The main clinical manifestations were seizures (79%) and haemorrhage (16%). The annual haemorrhage rate was 0.7%. The outcome after excision was good with improvement in seizures in 92% of patients. In the case series the surgical outcome was less favourable, reflecting inclusion of a higher proportion of patients with intractable epilepsy. In both the literature review and the case series, outcome was poorer in cases with a longer duration of seizures at the time of surgery.

CONCLUSIONS

The good surgical results, particularly in cases treated earlier, and the significant cumulative haemorrhage rate, suggest that excision is the optimum treatment. However, these factors have not been examined prospectively and, despite the availability of several retrospective studies, the optimum treatment, particularly for non-intractable cases, will only be determined by a prospective study.

Image-guided neurosurgery

Accurate localization of lesions and minimization of trauma to the surrounding brain are of paramount importance in intracranial surgery. Stereotactic frame systems provide highly accurate methods of localization, which has been further enhanced by the introduction of sophisticated imaging modalities, and recently by the development of interactive image-guided neurosurgical technology.

Neurenteric cyst of the cerebellopontine angle: case report

OBJECTIVE AND IMPORTANCE

We report a case of a neurenteric cyst of the cerebellopontine angle and review the five previously reported cases. The pathology and classification of these cysts are discussed.

CLINICAL PRESENTATION

The patient presented with a 1-month history of nausea, vomiting, vertigo, and sudden hearing loss.

INTERVENTION

The cyst was decompressed by a retrosigmoid approach. After recurrence of symptoms at 2 months, further decompression was required.

CONCLUSION

The patient achieved a good outcome after the second operation, with cessation of her vomiting and vertigo, although she had residual hearing loss. Four of the five previously reported patients experienced satisfactory outcomes after surgery. The definitive diagnosis of these rare lesions is made using immunocytochemical techniques.

Trigeminal neuralgia in patients with multiple sclerosis: lesion localization with magnetic resonance imaging

We performed conventional T2-weighted brain MRI examinations in six patients with multiple sclerosis (MS) and trigeminal neuralgia. In all patients brainstem lesions in positions expected to involve trigeminal fibers, particularly the entry zone of sensory fibers, were demonstrated. Compression of the trigeminal nerve by ectatic vessels, a recognized cause of idiopathic trigeminal neuralgia, was not observed. We conclude that in MS trigeminal neuralgia is usually caused by demyelinating lesions affecting pontine trigeminal pathways.

Incidence of postdural puncture headache following spinal anaesthesia for lower segment caesarean section with the 25 gauge polymedic spinal needle

The incidence of postdural puncture headache (PDPH) was studied in in-patients after spinal anaesthesia with 25 gauge Polymedic needle (Sprotte-like), for lower segment caesarean section (LSCS). A total of 281 women who underwent LSCS were studied, at the maternity unit of St. Peter's Hospital, Chertsey, Surrey, U.K. Of these, 125 women had a spinal, 93 general and 63 epidural anaesthesia. All the women were questioned about the presence of headache between the second and fourth post-operative day. Its severity was assessed with a visual analogue scale. Women who had an epidural or a general anaesthesia were used as controls. Out of 281 women studied, none complained of PDPH. Four women in the spinal anaesthetic group, complained of headache which did not have the characteristics of PDPH. The 25 gauge Polymedic spinal needle appears to be safe and satisfactory for performing spinal anaesthesia for LSCS.

Experimental and clinical studies on the putative therapeutic efficacy of cerebral irradiation (radiotherapy) in epilepsy

1. The majority of the published literature on the radiotherapeutic treatment of epilepsy suffers because it has involved neither radiotherapists nor epileptologists. 2. Papers have either been written describing an incidental beneficial effect (these suffer from being retrospective analyses) or by enthusiasts (where one must question patient selection). In addition there are a small number of very detailed and useful individual case reports. 3. Despite the reservations it would appear that radiation can have beneficial effects on seizures, and this effect has been described for a wide variety of conditions using a wide variety of treatment modalities. 4. There are grounds for prospective clinical trials to test the putative therapeutic efficacy of cerebral irradiation. However, it is essential that these are carried out by a group involving an established epilepsy surgery programme and a radiotherapy department conversant with the complex issues involved in focussed radiation treatment.

The scope of neurosurgery for elderly people

Patients treated by a single neurosurgeon over a period of 17 years have been reviewed in order to assess the volume and nature of neurosurgical work performed on patients aged over 65 years. Based on this data we report: (1) The age distribution of the principal neurosurgical conditions, drawing attention to those conditions which are over- and under-represented in elderly patients. (2) A steady increase in the number of patients over 65 admitted over the last 15 years. (3) The numbers and types of neurosurgical operations carried out on elderly patients at the present time compared with 10 years ago. (4) The outcome of first-time surgery for intracranial meningiomas in 144 patients analysed by age. It is clear that a large and increasing proportion of neurosurgical work is carried out on persons over the age of 65. Age by itself appears to be no bar to a good outcome after a major neurosurgical operation provided that the surgery is elective and is not accompanied by a diffuse neurological disturbance.

Occult spinal pseudomeningocele following a trivial injury successfully treated with a lumboperitoneal shunt: a case report

A patient with a traumatic occult spinal pseudomeningocele is presented. The possible etiology and the use of a lumboperitoneal shunt in this situation are discussed.