Proposal for a prospective multi-centre audit of chronic subdural haematoma management in the United Kingdom and Ireland.

BACKGROUND. Chronic subdural haematoma (CSDH) is a common condition that increases in incidence with rising age. Evacuation of a CSDH is one of the commonest neurosurgical procedures; however the optimal peri-operative management, surgical technique, post-operative care and the role of adjuvant therapies remain controversial. AIM. We propose a prospective multi-centre audit in order to establish current practices, outcomes and national benchmarks for future studies. METHODS. Neurosurgical units (NSU) in the United Kingdom and Ireland will be invited to enrol patients to this audit. All adult patients aged 16 years and over with a primary or recurrent CSDH will be eligible for inclusion. OUTCOME MEASURES AND ANALYSIS. The proposed outcome measures are (1) clinical recurrence requiring re-operation within 60 days; (2) modified Rankin scale (mRS) score at discharge from NSU; (3) morbidity and mortality in the NSU; (4) destination at discharge from NSU and (5) length of stay in the NSU. Audit standards have been derived from published systematic reviews and a recent randomised trial. The proposed standards are clinical recurrence rate < 20%; unfavourable mRS (4-6) at discharge from NSU < 30%; mortality rate in NSU < 5%; morbidity rate in NSU < 10%. Data will be submitted directly into a secure online database and analysed by the study's management group. CONCLUSIONS. The audit will determine the contemporary management and outcomes of patients with CSDH in the United Kingdom and Ireland. It will inform national guidelines, clinical practice and future studies in order to improve the outcome of patients with CSDH.

A report from the inaugural meeting of the British Neurosurgical Trainee Research Collaborative held in the Royal College of Surgeons of England, 19 October 2012.

Clinical research, which is essential for improving patient outcomes, is increasingly carried out in the context of networks established between multiple institutions. Research is also considered an important component of training curricula. The recent successful completion of a randomised trial (ROSSINI), which was led by general surgical trainees of the West Midlands Research Collaborative, has established the feasibility of trainee collaborative research networks. A research network for neurosurgical trainees in the UK and Ireland was, therefore, established following the meeting of the British Neurosurgical Trainee Association (BNTA) in Aberdeen on 19 April 2012. This BNTA initiative quickly gained the full support from the Society of British Neurological Surgeons and the UK Neurosurgical Research Network. The inaugural meeting of the British Neurosurgical Trainee Research Collaborative took place at the Royal College of Surgeons of England, London, on 19 October 2012. The purpose of this report is both to record progress to date and to promote this concept.

An unusual aneurysm of a basilar perforating artery presenting with a subarachnoid haemorrhage.

A 65-year-old man had a perimesencephalic subarachnoid haemorrhage with normal angiography initially. After a rebleed 5 days later, a repeat angiogram revealed a pea-like aneurysm a short distance behind and below the basilar bifurcation. It was not amenable to endovascular treatment and the feeding vessel was coagulated and divided at open surgery via a sub temporal approach. He developed a right hemiparesis and dysphasia, from which he slowly recovered. Basilar perforating artery aneurysms are extremely rare, with only 4 previous cases reported.

Endovascular treatment of ruptured intracranial aneurysms during pregnancy: is this the best way forward? Case report and review of the literature.

OBJECTIVE AND IMPORTANCE: Subarachnoid haemorrhage in pregnancy has traditionally been treated by surgical clipping however lately cases of successful coiling have been reported. Nevertheless, the long-term outcome of coiling is not well known in pregnant women. Mortality due to rebleeding of an incompletely treated aneurysm remains high. Only 15 cases of successful endovascular coiling during pregnancy have been reported so far. CLINICAL PRESENTATION: We report the case of a pregnant woman who presented with aneurysmal subarachnoid hemorrhage (WFNS Grade III) due to rupture of a right posterior communicating artery aneurysm. INTERVENTION: The patient underwent endovascular coiling successfully followed by an elective caesarian section and delivery of a healthy baby. However, during the course of a 2-year follow up the patient had suffered two relapses of the coiled aneurysm which required additional treatment. These events have affected her choice of extending her family. CONCLUSION: The small risk of recurrence and the potential impact on future pregnancies should be explicitly communicated to patients in cases of endovascular coiling.

Virchow-Robin spaces in idiopathic normal pressure hydrocephalus: a surrogate imaging marker for coexisting microvascular disease?

BACKGROUND: Virchow-Robin spaces (VRSs) surround perforating cerebral arteries and are reported to be found with increasing frequency with advancing age. In addition, some studies indicate an association between VRSs and vascular dementias. The present study examined the incidence of VRSs in patients with idiopathic normal pressure hydrocephalus (INPH) and considered their use as a potential surrogate imaging marker of coexisting microvascular disease in patients with this condition. METHODS: The MRI incidence of VRS in the centrum semiovale (CS), basal ganglia (BG), mesencephalon (MES), and the subinsular (SI) region was measured in 12 patients with INPH and in 12 control subjects, using the scoring system proposed by Patankar et al. (Am J Neuroradiology 26:1512, 2005). Historical control data were also used for further comparison. RESULTS: All 12 INPH patients had clearly visible VRSs, distributed in the CS (all 12), basal ganglia (11/12), SI region (9/12), and MES region (6/12). The mean Patankar scores of the INPH group were BG 2.25, CS 1.66, SI 0.91, and ME 0.5. The respective scores for our control group were 1.41, 1.5, 1.16, and 0.16, and for historical controls were 1.46, 0.51, 0.96, and 0.51. There were, however, no statistically significant differences between the INPH patients and either of the control groups. No correlation was found between age and the overall incidence of VRS. CONCLUSION: This preliminary study suggests that there may be a higher incidence of VRSs in patients with INPH, when compared with normal patients of similar age, but our small numbers prevent us from demonstrating statistical significance, and larger studies are clearly required.

Cognitive, biochemical, and imaging profile of patients suffering from idiopathic normal pressure hydrocephalus.

INTRODUCTION: It has still not been clearly established whether the cognitive deficits of idiopathic normal pressure hydrocephalus (iNPH) are caused by a disturbance in cerebrospinal fluid (CSF) dynamics or an underlying metabolic disturbance. OBJECTIVE: To identify the possible associations between biochemical markers, the neuroimaging characteristics, and cognitive deficits of patients undergoing investigations for possible iNPH. METHODS: A CSF sample obtained during a lumbar puncture from 10 patients with iNPH was analyzed for several biochemical markers (lactate, 8-isoprostane, vascular endothelial growth factor [VEGF], neurofilament heavy protein, glial fibrillary acidic protein, amyloid beta 1-42, and total tau). All patients underwent a battery of neuropsychological testing and imaging as part of their selection process for their suitability for CSF diversion surgical procedure. Volumetric analysis of imaging was carried out measuring the ventricular volume (VV), intracranial volume (ICV), periventricular lucencies, deep white matter hyperintensities, and white matter (WM) volume, as well as their ratios. RESULTS: A significant negative correlation of preoperative symptom duration and total tau levels (R = -0.841, P = .002) was found. There was a significant positive correlation (R = 0.648, P = .043) between the levels of VEGF and the VV/ICV ratio. There was a significant positive correlation of the levels of glial fibrillary acidic protein and the VV/deep white matter hyperintensities ratio (R = 0.828, P = .006). A significant negative correlation was observed between the levels of neurofilament heavy protein and the VV/ICV ratio (R = -0.657, P = .039) and the WM volume (R = -0.778, P = .023). Lactate levels were lower for patients performing in the normal range on the Recognition Memory Test for faces. Patients who performed better in the Recognition Memory Test words test had higher ICV volumes. All the patients in this study showed below normal performance when the subcortical function was assessed. CONCLUSION: The positive correlation of VEGF with the severity of ventriculomegaly may indicate that this is because of the transmantle pressure gradient; this response may not be because of hypoxia but represents an attempt at neuroregeneration. The degree of reactive gliosis correlates inversely with the severity of WM lesions. Neuronal degeneration is negatively correlated with the volume of the WM in these patients. The small association of volumetry and the cognitive profile of these patients may be consistent with a direct biochemical disturbance being responsible for the cognitive deficit observed. Ongoing studies with set protocols for neuropsychological assessment and volumetric analysis are warranted to further elucidate on the preliminary results of the current study.

Use of the proGAV shunt valve in normal-pressure hydrocephalus.

BACKGROUND: Overdrainage is a common complication associated with shunt insertion in normal-pressure hydrocephalus (NPH) patients. Using adjustable valves with antigravity devices has been shown to reduce its incidence. The optimal starting setting of an adjustable shunt valve in NPH is debatable. OBJECTIVE: To audit our single-center practice of setting adjustable valves. METHODS: We performed a retrospective review of clinical records of all NPH patients treated in our unit between 2006 and 2009 by the insertion of shunts with a proGAV valve, recording demographic and clinical data, shunt complications, and revision rates. Radiological reports of postoperative follow-up computed tomography scans of the brain were reviewed for detected subdural hematomas. RESULTS: A proGAV adjustable valve was inserted in 50 probable NPH patients between July 2006 and November 2009. Mean ± SD age was 76 ± 7 years. Mean follow-up was 15 months. The initial shunt setting was 6 ± 3 cm H2O, and the final setting was 4.9 ± 1.9 cm H2O. Nineteen patients required 24 readjustment procedures (readjustment rate, 38%; readjustment number, 0.48 times per patient). One patient (2%) developed delayed bilateral subdural hematoma after readjustment of his shunt valve setting as an outpatient. CONCLUSION: Starting with a low opening pressure setting on a proGAV adjustable shunt valve does not increase the chances of overdrainage complications and reduces the need for repeated readjustments.

Is there a difference in outcomes of patients with idiopathic intracranial hypertension with the choice of cerebrospinal fluid diversion site: a single centre experience.

UNLABELLED: The visual and headache outcomes in patients with idiopathic intracranial hypertension (IIH) undergoing cerebrospinal fluid diversion with a lumboperitoneal (LPS) or ventriculoperitoneal shunting (VPS) have not been well reported. The aims of this study were to: (a) to assess outcomes of CSF diversion in IIH, (b) to understand influence of the type of shunt in outcomes, and (c) to understand factors predisposing in shunt failure. METHODS: The medical records of 34 patients who underwent cerebrospinal fluid diversion (CSFD) between 1996 and 2007 were retrieved and epidemiological and clinical data was collected. RESULTS: The mean age was 35 (±7.9) years. Thirty-four patients underwent 63 shunt placements in total. 85% follow-up was achieved. The mean follow-up for the entire group was 28.9 (±31.8) months. Headaches improved more than visual disturbances. There was no significant difference between the groups that received a VPS and those receiving an LPS in both headache and visual outcomes. The rate of complications was 20.5% and the need for revision was 35% for the whole group. Patients with LPS suffered more complications and first time revisions than patients with VPS. No factor recorded could predict the need for revision or final outcomes. The shunts of patients receiving a VPS tend to survive longer than those receiving primarily an LPS, however the difference is not statistically significant. CONCLUSIONS: Predicting which patients will improve is not possible at present. The influence of site diversion is not critical but patients with VPS have less complications and revisions than those receiving a LPS.

Use of cerebrospinal fluid amyloid-ß and total tau protein to predict favorable surgical outcomes in patients with idiopathic normal pressure hydrocephalus.

OBJECT: The prognostic value of CSF biomarkers in patients with idiopathic normal pressure hydrocephalus (iNPH) has not been adequately studied to date. The aim of this study was to identify CSF markers of favorable surgical outcome in patients with iNPH undergoing the insertion of a ventriculoperitoneal shunt. METHODS: Ventricular CSF was collected intraoperatively from 22 patients with iNPH and enzyme-linked immunosorbent assay was used to analyze the levels of amyloid-ß 1-42 (Aß(1-42)) and total tau protein. The Black grading scale was used to assess outcomes at 6 months. Receiver operating characteristic (ROC) curves were obtained and discriminant function analysis was undertaken to provide sensitivity and specificity figures for each marker as well as their combination. RESULTS: The mean age of the patients was 71.45 years (± 9.5 years [SD]). Follow-up was achieved in 21 patients. Seventeen patients had a favorable outcome and 4 patients had unfavorable outcome at 6 months. An Aß(1-42) level of 180 pg/ml had a sensitivity of 35% and a specificity of 20% for predicting a favorable outcome at 6 months. A total tau level of 767 pg/ml will have a sensitivity of 17% and a specificity of 20% for predicting a favorable outcome at 6 months. A combination of Aß(1-42) and total tau levels predicted favorable outcomes with a sensitivity of 80% and specificity of 82.4%. CONCLUSIONS: In this pilot study a combination of Aß(1-42) levels and total tau protein levels predicted favorable surgical outcomes at 6 months with adequate accuracy to be of clinical use. Further study in a larger group with longer follow-up is warranted.

Working towards patient oriented outcome assessment in normal pressure hydrocephalus, what is the most important?

OBJECTIVE: To date, there is no standard outcome assessment scale for shunt treatment in normal pressure hydrocephalus (NPH). In designing such scale, the relative weight of each of the common presentations of the condition from the patient's or his/her carer's point of view should be taken into consideration. METHODS: A questionnaire was sent to 24 patients treated for NPH and their family/carer, assessing the patient and carer categorization of the preoperative main complaint, the weight they give to each of the common presentations of NPH and their satisfaction with treatment. RESULTS: Twenty-two patients and 20 carers replied. Gait disturbance was the main complaint from both patient's (86%) and carer's (75%) point of view. Similarly, gait disturbance was considered as the most important problem that needs improvement by both patients (77%) and carers (65%). Incontinence was considered the second most important area by 11 (50%) patients and seven (35%) carers. When asked to quantify their satisfaction out of 10, patients had a mean of 7.2 while carers gave a mean of 7.5. Comparing subjective perspective of improvement with that of objective improvement on 10 m walking test and neuropsychological assessment, all patients who improved objectively were perceived as improved to a satisfactory degree by carers. CONCLUSION: Walking/balance should be given far greater weight than other components of the NPH triad in future outcome assessment scales in accordance with patient/family perception.

Rostrocaudal dynamics of CSF biomarkers.

The rostrocaudal gradient (RCG) of markers present in cerebrospinal fluid (CSF) has not been studied adequately due to lack of appropriate control populations and ethical restrictions. The aim of this study is to understand the rostrocaudal gradient of CSF biomarkers. We contacted a study comparing CSF levels of seven biomarkers from cisternal (rostral) and lumbar (caudal) CSF obtained from patients with trigeminal neuralgia and tension-type headache. The RCGs of CSF/serum albumin ratio, 8-isoprostane. GFAP, total tau and beta amyloid protein were higher than one. The RCGs of lactate, VEGF and the heavy chain of neurofilament protein were lower than one. The study provides new values for several commonly examined markers of cisternal CSF. Knowledge of the RCG gradient of different CSF markers is important in interpreting studies reporting ventricular CSF values.

Investigating shunt function using continuous intracranial pressure monitoring in adults: single center experience.

OBJECT: Managing symptomatic ventriculoperitoneal shunts with no clear evidence of shunt malfunction either clinically or radiologically can be a difficult task. The aim of this study was to assess intracranial pressure (ICP) monitoring as a method of investigating shunt function. METHODS: The authors performed a retrospective analysis of 38 continuous ICP monitoring procedures done in patients with ventriculoperitoneal shunts and suspected shunt malfunction. RESULTS: Thirty-eight procedures were performed in 31 patients between January 2005 and October 2008. Sixteen recordings were normal, 6 revealed overdrainage or low pressure, 11 indicated underdrainage or high pressure, and 5 showed variable shunt function. Based on the findings after 20 procedures (53%), patients were treated conservatively: 4 by readjusting the valve setting and 16 by referral to the headache neurologist for medical treatment. Forty-five percent of the conservatively treated patients improved. Surgical exploration was undertaken following 18 procedures (47%); 72% of the surgically treated patients improved. CONCLUSIONS: Continuous ICP monitoring using an intraparenchymal probe is a safe and effective method of investigating adult hydrocephalus.

Continuous intracranial pressure monitoring in pseudotumour cerebri: Single centre experience.

OBJECTIVE: Investigating pseudotumour cerebri (PTC) patients who do not fulfil the diagnostic criteria, or those presenting post-shunt insertion with recurrent symptoms and signs, with no clear evidence of shunt malfunction, present a diagnostic challenge. PTC patients who underwent continuous intracranial pressure (ICP) monitoring in our unit were reviewed retrospectively. RESULTS: Twenty-six ICP monitoring procedures were done on 20 patients. Eleven patients had normal pressure, 2 overdrainage/low pressure, 11 underdrainage/high pressure and 2 variable pressures. On the basis of these results 12 patients were managed conservatively: 11 patients were referred to headache team and 1 patient had readjustment of an adjustable valve shunt setting; of those 3 patients had improved symptoms on their first post-operative clinic review. On the other hand, 14 patients had surgery: 5 had shunt revision and 9 had shunt insertion; of those 5 patients improved. CONCLUSION: ICP monitoring using an intraparenchymal probe is a safe and effective diagnostic technique in investigating PTC when indicated. A multidisciplinary approach achieves best results in terms of successful management and follow-up.

Ventriculosinus shunt.

Hydrocephalus can be managed successfully with cerebrospinal fluid shunting to extracranial compartments, most commonly the peritoneum. However, current shunt systems are not ideal with high revision rates on long-term follow-up. Draining the cerebrospinal fluid from the cerebral ventricles to the cerebral venous sinuses could mimic the physiological conditions with the added advantages of avoiding overdrainage and extracranial recipient site complications. A literature search was carried out using the keywords hydrocephalus, shunt, venous sinus and sagittal sinus. Seven clinical series of ventriculosinus shunts with a total of 265 patients were found. None of the patients developed venous sinus thrombosis, air embolism or intra-operative sinus bleeding. Ventriculosinus shunt is a potential alternative that can be done under local anaesthetic in ill patients where traditional shunts recipient sites are not feasible. However, further studies with extended follow-up period would provide better understanding of the suitability and indications of this technique.

Adjustable shunt valve-induced magnetic resonance imaging artifact: a comparative study.

OBJECT: In this paper, the authors' goal was to compare the artifact induced by implanted (in vivo) adjustable shunt valves in spin echo, diffusion weighted (DW), and gradient echo MR imaging pulse sequences. METHODS: The MR images obtained in 8 patients with proGAV and 6 patients with Strata II adjustable shunt valves were assessed for artifact areas in different planes as well as the total volume for different pulse sequences. RESULTS: Artifacts induced by the Strata II valve were significantly larger than those induced by proGAV valve in spin echo MR imaging pulse sequence (29,761 vs 2450 mm(3) on T2-weighted fast spin echo, p = 0.003) and DW images (100,138 vs 38,955 mm(3), p = 0.025). Artifacts were more marked on DW MR images than on spin echo pulse sequence for both valve types. CONCLUSIONS: Adjustable valve-induced artifacts can conceal brain pathology on MR images. This should influence the choice of valve implantation site and the type of valve used. The effect of artifacts on DW images should be highlighted pending the development of less MR imaging artifact-inducing adjustable shunt valves.

Noninvasive biomarkers in normal pressure hydrocephalus: evidence for the role of neuroimaging.

OBJECT: Normal pressure hydrocephalus (NPH) represents a treatable form of dementia. Recent estimates of the incidence of this condition are in the region of 5% of patients with dementia. The symptoms of NPH can vary among individuals and may be confused with those of patients with multi-infarct dementia, dementia of the Alzheimer type, or even Parkinson disease. Traditionally the diagnosis of NPH could only be confirmed postoperatively by a favorable outcome to surgical diversion of CSF. The object of this literature review was to examine the role of structural and functional imaging in providing biomarkers of favorable surgical outcome. METHODS: A Medline search was undertaken for the years 1980-2006, using the following terms: normal pressure hydrocephalus, adult hydrocephalus, chronic hydrocephalus, imaging, neuroimaging, imaging studies, outcomes, surgical outcomes, prognosis, prognostic value, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy. RESULTS: The query revealed 16 studies that correlated imaging with surgical outcomes offering accuracy results. Three studies fulfilled the statistical criteria of a biomarker. A dementia Alzheimer-type pattern on SPECT in patients with idiopathic NPH, the presence of CSF flow void on MR imaging, and the N-acetylaspartate/choline ratio in patients with the secondary form are able to predict surgical outcomes with high accuracy. CONCLUSIONS: There is at present Level A evidence for using MR spectroscopy in patients with secondary NPH, and Level B evidence for using SPECT and phase-contrast MR imaging to select patients with idiopathic NPH for shunt placement. The studies, however, need to be repeated by other groups. The current work should act as a platform to design further studies with larger sample sizes.

Ongoing search for diagnostic biomarkers in idiopathic normal pressure hydrocephalus.

Idiopathic normal pressure hydrocephalus is a syndrome, which typically has a clinical presentation of gait/balance disturbance, often accompanied by cognitive decline and/or urinary incontinence. Its diagnosis is based on relevant history and clinical examination, appropriate imaging findings and physiological testing. The clinical picture of idiopathic normal pressure hydrocephalus may occasionally be difficult to distinguish from that of Alzheimer's dementia, subcortical ischemic vascular dementia and Parkinson's disease. The aim of this article is to systematically review the literature from the last 29 years in order to identify cerebrospinal fluid (CSF) or imaging biomarkers that may aid in the diagnosis of the syndrome. The authors concluded that no CSF or imaging biomarker is currently fulfilling the criteria required to aid in the diagnosis of the condition. However, a few studies have revealed promising CSF and imaging markers that need to be verified by independent groups. The reasons that the progress in this field has been slow so far is also commented on, as well as steps required to apply the current evidence in the design of future studies within the field.