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.

The longitudinal profile of CSF markers during external lumbar drainage.

BACKGROUND: External lumbar drainage (ELD) is known as a good predictor of favourable outcome in shunting patients suffering from idiopathic normal pressure hydrocephalus (iNPH). METHODS: Eleven patients suffering from iNPH had a lumbar drain (LD) inserted for 72 h and participated in a research study to quantify any improvement in their clinical symptoms. The lumbar cerebrospinal fluid (CSF) levels of lactate, 8-isoprostane, vascular endothelial growth factor (VEGF), glial fibrillar acidic protein (GFAP), neurofilament (heavy chain) protein (NF (h)), Abeta(1-42) (beta-amyloid) and total tau were assayed samples from all three time points. RESULTS: The concentrations of lactate, VEGF, GFAP and tau increased significantly during the 72 h of drainage. There were also increases in 8-isoprostane and Abeta(1-42) (non significant). The concentration of NF (h) was reduced significantly following 72 h of drainage. There was a significant positive correlation between Abeta(1-42) and total tau in the first sample. GFAP was negatively correlated in a significant fashion with both Abeta(1-42) and total tau. NF (h) was negatively correlated with VEGF. CONCLUSION: Evidence is provided that ELD is producing measurable changes in the CSF composition of patients with iNPH. The present paper discusses how such changes may be implicated in the pathophysiology of the condition.

Development of cavernous haemangioma following radical chemo-radiotherapy for nasopharyngeal carcinoma.

OBJECTIVE: We report an adult case of nasopharyngeal carcinoma treated with radical chemo-radiotherapy, with subsequent development of a histologically proved temporal cavernous haemangioma within the radiation field. METHOD: Case report and review of the current literature concerning radiation-induced, secondary, space-occupying lesions. CONCLUSION: The increasing role of radiotherapy in nasopharyngeal carcinoma treatment, together with improved patient survival, is likely to lead to radiation-induced, secondary, space-occupying lesions being encountered more frequently. We emphasise the need to be vigilant for this important but relatively rare complication, which has significant associated morbidity.

Does conservative management for brain stem cavernomas have better long-term outcome?

There has been a controversy in the last 15 years on the correct management of brain stem cavernomas. We have reviewed our experience of the last 10 years in a single Institution and reviewed related literature published in the last 15 years. We recorded the demographics, clinical presentation, rebleeding episodes, incidence of neurological events and outcome assessed by recording the change of the modified Rankin scale in 21 cases. Univariate analysis was applied to test the effect of demographics, and presentation on the incidence and timing of rebleeding, chance of having a new neurological event, the number of subsequent neurological events and outcomes. Six cases were treated with surgery and 15 cases were managed conservatively. We obtained follow-up data in 20 patients (95%). Mean follow-up period was 79.7 months (range: 6-244, median 70 months). There were 0.05 rebleeding events per patient-year and 0.1 episodes of neurological deterioration per patient-year. No mortality was noted in either the surgical or the non-surgical group. Three of the six surgical cases had a reoperation. The outcome was improved in one patient, unchanged in 1, and worse in 3 surgical patients. In the case of conservative management the outcome was improved in two patients, unchanged in five patients, and worse in eight patients. Outcome was worse in the case of multiple cavernomas (p = 0.012). Our findings suggest that conservative management may be appropriate in individual cases when compared with surgery, but this difference was not statistically significant enough in order to support a change in practice. The natural history of brain stem cavernomas appears more benign than previously thought.

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.

Mixed glioneuronal tumour of the fourth ventricle with prominent rosette formation.

We describe three unusual tumours characterized by a mixture of glial and neuronal differentiation, involvement of the posterior fossa and formation of rosettes. Mixed glial-neuronal tumours of the posterior fossa are rare and poorly described neoplasms. However, several distinctive entities have appeared in the literature over recent years under a variety of different names. Our cases demonstrate the morphological features of the 'rosette-forming glioneuronal tumour of the fourth ventricle', a recently identified tumour characterised by its unique location, neurocytic pseudo-rosette formation and the presence of a low grade astrocytoma component. The long term prognosis of these tumours remains unclear. However, the clinical data available including the cases presented here, along with the histological features, suggest that these are low grade tumours with a good prognosis after surgical resection.

ALK positive inflammatory myofibroblastic tumour of the pineal region.

Inflammatory myofibroblastic tumours (IMTs) are an uncommon spindle cell neoplasm with a dense inflammatory infiltrate, usually encountered in children. IMTs of the central nervous system are extremely rare. This report describes the case of an IMT in a 61 year old man, in the pineal region. The tumour was completely excised, and immunohistochemistry demonstrated anaplastic lymphoma kinase 1 expression. There was no tumour recurrence during 18 months of follow-up. Our case extends both the age range and sites of occurrence of this rare tumour.

Subdural haematoma associated with an arachnoid cyst after repetitive minor heading injury in ball games.

We report the case of a chronic subdural haematoma caused by repetitive heading of a football which led to the diagnosis of a middle fossa arachnoid cyst. The association between arachnoid cysts and subdural haematoma is discussed as are safety implications in sporting injuries.

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.

Rapid enlargement of a vestibular schwannoma following gamma knife treatment.

Stereotactic radiosurgery has been proposed as the first line treatment for acoustic tumours and has been particularly advocated in cases of Type 2 Neurofibromatosis (NF2) with bilateral acoustic nerve tumours. We present the case of a 22-year-old male with NF2 and bilateral acoustic nerve tumours. He underwent an uncomplicated excision of the larger, left sided lesion. Histology showed a benign acoustic schwannoma with no atypical features. One year later he underwent stereotactic radiosurgery (Gamma Knife 1500 cGy) to the right sided lesion. After initial swelling, within 12 months the tumour had reduced in size and undergone central necrosis. However, 2 years later MRI of the brain revealed a dramatic increase in the size of the right sided tumour, with considerable brain stem compression. The patient subsequently died. This highly unusual case highlights the need for careful clinical and radiological follow up. in patients with acoustic tumours, regardless of the treatment method employed.

Auditing patient experience and satisfaction with neurosurgical care: results of a questionnaire survey.

The objective of this study was to determine the current level of patient satisfaction with neurosurgical services from the time of initial referral to hospital discharge. The survey was camed out by a self-administered postal questionnaire survey from the National Hospital for Neurology and Neurosurgery, London, UK. The participants were 364 patients discharged from the unit within one calendar year. The main outcome measures were level of satisfaction with various aspects of care, as measured by fixed response and free text style questions. Most patients are happy with the waiting time to see a neurosurgeon and the wait for subsequent admission acceptable, but many would have preferred it to be shorter. Twenty-seven had their original admission date cancelled, but most were happy with the explanation offered. Weaknesses in the management of outpatient clinics were highlighted, 35% of patients waiting more than half an hour to be seen. The great majority were happy with various aspects of communication with the neurosurgical team. Few patients were given the opportunity to follow up their visit with literature provided or a visit to a specialist nurse (17 and 9%, respectively). However, both were considered very useful, in particular, 93% highly valued a meeting with the specialist nurse. There was a dichotomy of opinion over the course of the inpatient stay. While most aspects of care received 70-80% satisfaction, the management of discharge received the most criticism. This was thought to represent a pooling of resources around the most needy patients. The majority of patients were discharged home (76%), only a third feeling that staff did everything possible to help this process. Very few received printed information. Again, those who had seen the specialty nurse had much higher levels of satisfaction. Patient satisfaction audit gives useful data on patients' perception and satisfaction with care that may not be apparent on more traditional audit measures such as length of stay, which focus more on a unit's efficiency. This study shows generally high levels of patient satisfaction with neurosurgical practice but highlights areas needing attention and expansion, such as access to a specialist nurse and relevant literature. Dissatisfaction with various administrative arrangements are clearly shown and provide an opportunity for patient centred improvements.

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.

Interactive image-guided transcallosal microsurgery for anterior third ventricular cysts.

Although the treatment of colloid cysts remains controversial, high viscosity and small volume are poor prognostic indicators for successful burr hole aspiration and cortical incision via craniotomy may be associated with postoperative epilepsy. The anterior transcallosal approach provides a direct and adequate pathway to the lateral ventricles, where the foramen of Monro serves as a natural entrance into the anterior third ventricle, especially when the foramen is dilated by a lesion. When the midsuperior portion of the IIIrd ventricle cannot be reached, the interforniceal or the subchoroidal exposures have been advocated. Stereotactic techniques contribute to a minimal invasive approach and reduce morbidity. Nine patients harbouring anterior third ventricular cysts (seven colloids and two intrinsic craniopharyngiomas) underwent anterior transcallosal microsurgical excision assisted by an interactive infrared-based image guided system (EasyGuide, Neuro, Philips). There were 4 men and 5 women ranging in age from 15 to 42 years (mean 28.5). Transcallosal transforaminal (5 cases) or interforniceal (4 cases) approaches allowed total excision in eight patients and subtotal in one. Postoperative morbidity included a case of transient hemiparesis and a case of transient short-term memory disturbances; both resolved in the first months. Mortality was zero. Particular advantages of the method were accurate trajectory and position of callosotomy incision determination, visualisation and avoidance of superior saggital sinus, retraction of bridging veins and the often variable pericallosal arteries, spatial orientation within the ventricular system, and identification of the periventricular anatomical structures.

Giant temporo-occipital sinus pericranii. A case report.

A rare case of a giant, temporo-occipital sinus pericranii is presented. A 38-year-old male presented with minor symptoms of headache and heaviness over an enlarging temporo-occipital bone defect. Within the defect a soft, compressible, mass lesion was observed, which varied in size with changes in intracranial pressure. Radiological imaging demonstrated bone erosion around a fluid filled mass, which on angiography communicated via a series of channels with the transverse sinus. A diagnosis of sinus pericranii was made. Due to the risk of future complication the patient elected to undergo surgery, which successfully resected the mass and obliterated the venous communications with the diploic veins and transverse sinus. The classification, aetiology, differential diagnosis, radiological characteristics and management options relating to sinus pericranii are discussed.