Introduction Tinnitus is a symptom commonly associated with idiopathic intracranial hypertension ... more Introduction Tinnitus is a symptom commonly associated with idiopathic intracranial hypertension (IIH) that can have a profound effect on quality of life. We aim to determine tinnitus symptom response after dural venous sinus stenting (DVSS) or CSF diversion with a shunt, in patients with both pulsatile (PT) and non-pulsatile tinnitus (NPT). Methods Single-centre cohort of IIH patients (2006-2016) who underwent 24-h ICP monitoring (ICPM). An un-paired t test compared ICP and pulse amplitude (PA) values in IIH patients with PT vs. NPT. Results We identified 59 patients with IIH (56 F:3 M), mean age 32.5 ± 9.49 years, 14 of whom suffered from tinnitus. Of these 14, seven reported PT and seven reported NPT. Patients with tinnitus had a mean 24-h ICP and PA of 9.09 ± 5.25 mmHg and 6.05 ± 1.07 mmHg respectively. All 7 patients with PT showed symptom improvement or resolution after DVSS (n = 4), secondary DVSS (n = 2) or shunting (n = 1). In contrast, of the 7 with NPT, only 1 improved post intervention (DVSS), despite 2 patients having shunts and 5 having DVSS. Conclusions NPT and PT were equally as common in our group of IIH patients. DVSS appears to be an effective management option for IIH patients with a clear history of pulsatile tinnitus. However, non-pulsatile tinnitus was more persistent and did not respond well to either DVSS or CSF diversion.
BACKGROUND CONTEXT: Cerebrospinal fluid (CSF) leak following spinal surgery is a relatively commo... more BACKGROUND CONTEXT: Cerebrospinal fluid (CSF) leak following spinal surgery is a relatively common surgical complication. A small group of CSF leak patients require multiple surgical repairs and prolonged hospital admission. Spinal CSF leaks are usually classically associated with symptoms of low intracranial pressure (ICP). However, there is a paucity of literature investigating the associated CSF dynamics. PURPOSE: Scientific investigation of persistent spinal CSF leak post-surgery. STUDY DESIGN/SETTING: Retrospective cohort study. PATIENT SAMPLE: Patients with persistent CSF leak referred to the hydrocephalus service in our unit for intracranial pressure monitoring. OUTCOME MEASURES: Physiological and clinical outcome. METHODS: Retrospective case series study of patients with persistent CSF leak referred to the hydrocephalus service in our unit for intracranial pressure monitoring. Medical notes were reviewed for clinical presentation, management and outcome. Images were reviewed and ICP data were analysed. All patients underwent continuous ICP monitoring using Spiegelberg ICP bolts. RESULTS: Three patients had spinal fixation surgery, complicated by prolonged CSF leaks (mean of 56 days). Each patient required two reexploration spinal surgeries and multiple lumbar drains insertions prior to 24 hours of ICP monitoring. All patients were shown to have raised ICP (>15.2 mmHg). One patient underwent a right transverse venous sinus stent insertion. Two patients underwent insertion of ventriculoperitoneal shunts (VPS). All three had resolution of their CSF leaks immediately post intervention. CONCLUSIONS: Our results suggest that abnormal cerebrospinal fluid dynamics should be explored in patients with persistent CSF leak post spinal surgery. Whether abnormal pressure and dynamics represent a pre-existing abnormality or is induced by spinal surgery should be subject for further studies. CONFLICTS OF INTEREST: Nil. FUNDING SOURCES: Nil.
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
The optimal management of patients with ventriculoperitoneal or lumboperitoneal shunts undergoing... more The optimal management of patients with ventriculoperitoneal or lumboperitoneal shunts undergoing abdominal or pelvic surgery for unrelated reasons is often unclear due to the paucity of guidelines in this field. In this review, we outline key issues in managing these patients. Specifically, we address issues relating to pre-operative planning, avoidance of shunt-related complications such as infection and malfunction, and specific management of neurological symptoms in the post-operative period. A retrospective study was carried out analysing correspondence between general surgeons and a specialist hydrocephalus unit over a 4-year period relating to management of patients with ventriculoperitoneal and lumboperitoneal shunts undergoing abdominal or pelvic surgery. A literature review was carried out to identify available evidence in this field. 30 queries from general surgeons were identified comprising 12 main themes. 16 relevant publications were identified. We summarised these to answer these queries. The management of shunted patients may present challenges and uncertainties in an abdominal or pelvic surgery setting. This paper provides guidelines and clarity in this field by discussing and summarising reported data in the literature.
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Raised white cell count (WCC) in lumbar CSF is a commonly used marker of meningitis. The effect o... more Raised white cell count (WCC) in lumbar CSF is a commonly used marker of meningitis. The effect of cranial neurosurgery per se on lumbar WCC is not established. At this single centre, many patients undergo ICPM followed by lumboperitoneal shunt (LPS), with lumbar CSF WCC samples taken during insertion. We aimed to determine the effect of ICP bolt insertion on lumbar CSF WCC. We undertook a retrospective analysis of lumbar CSF samples in patients who had recently undergone 24-h ICPM. Thirty-three patients (16F:7M) aged 43.31 ± 12.1 years (mean ± SD) had lumbar CSF samples after ICPM. Fourteen had CSF sampled within 6 weeks and 19 after 6 weeks of ICPM. Twenty-five samples were taken during LPS insertion, 5 during lumbar drainage/puncture and 3 during LPS revision. All 33 patients were afebrile at the point of CSF sampling. The mean lumbar WCC within 6 weeks of ICPM was significantly higher than the mean lumbar WCC after 6 weeks, being 15.4 ± 18.0 and 2.32 ± 1.79 cells/microlitre respectively respectively. There was no significant increase in RBC. In patients with raised CSF WCC, 60% of raised WCC were predominantly lymphoctyes and 40% predominantly neutrophils. Only one patient grew an organism (S. aureus). We conclude that lumbar CSF WCC can be raised following minor intracranial surgery, despite no clinical sign of infection. We caution against using lumbar CSF WCC values independently as the only marker of infection following neurosurgery.
Background Elective intraparenchymal intracranial pressure (ICP) monitoring is useful for the dia... more Background Elective intraparenchymal intracranial pressure (ICP) monitoring is useful for the diagnosis and treatment of hydrocephalus and cerebrospinal fluid (CSF) disorders. This retrospective study analyzes median ICP and pulse amplitude (PA) recordings in neurosurgically naïve patients undergoing elective ICP monitoring for suspected CSF disorders. Methods Retrospective review of prospectively collated database of neurosurgically naïve patients undergoing elective ICP monitoring for suspected hydrocephalus and CSF disorders. Following extraction of the median ICP and PA values (separated into all, day and night time recordings), principal component analysis (PCA) was performed to identify the principal factors determining the spread of the data. Exploratory comparisons and correlations of ICP and PA values were explored, including by post hoc diagnostic groupings and age. Results A total of 198 patients were identified in six distinct diagnostic groups (n = 21-47 in each). The PCA suggested that there were two main factors accounting for the spread in the data, with 61.4% of the variance determined largely by the PA and 33.0% by the ICP recordings. Exploratory comparisons of PA and ICP between the diagnostic groups showed significant differences between the groups. Specifically, significant differences were observed in PA between a group managed conservatively and the Chiari/ syrinx, IIH, and NPH/LOVA groups and in the ICP between the conservatively managed group and high-pressure, IIH, and low-pressure groups. Correlations between ICP and PA revealed some interesting trends in the different diagnostic groups and correlations between ICP, PA, and age revealed a decreasing ICP and increasing PA with age. Conclusions This study provides insights into hydrodynamic disturbances in different diagnostic groups of patients with CSF hydrodynamic disorders. It highlights the utility of analyzing both median PA and ICP recordings, stratified into day and night time recordings.
Objective To evaluate the utility of brain MRI and ophthalmic biomarkers for the prediction of in... more Objective To evaluate the utility of brain MRI and ophthalmic biomarkers for the prediction of intracranial hypertension, we have studied the association between 6 biomarkers and 24-hour intracranial pressure (ICP) monitoring results in 45 patients.Methods This single-center observational study includes patients who underwent 24-hour ICP monitoring, brain MRI (within 3 months), and ophthalmic assessment (during ICP monitoring). Six biomarkers were investigated: pituitary gland shape, vertical tortuosity of the optic nerve, distension of the optic nerve sheath, optic disc protrusion (MRI), papilledema (slit lamp biomicroscopy), and spontaneous venous pulsations (SVP, infrared video recordings).Results Forty-five patients (mean age 39 ± 14 years, 38 women) met the inclusion criteria. All 6 biomarkers had a significant association with 24-hour ICP. Concave pituitary gland was observed with moderately elevated median ICP. Protrusion of the optic disc (MRI), papilledema, and absence of SVP were associated with the highest median ICP values. Twenty patients had raised ICP (median 24-hour ICP >5.96 mm Hg, cutoff obtained through Youden index calculation). Patients with all normal biomarkers had normal median ICP in 94% (standard error 6%) of the cases. All patients with ≥3 abnormal biomarkers had intracranial hypertension. The combination of at least 1 abnormal biomarker in MRI and ophthalmic assessments was highly suggestive of intracranial hypertension (area under the curve 0.94, 95% confidence interval 0.93–0.94)Conclusions Brain MRI and ophthalmic biomarkers can noninvasively guide the management of patients with suspected CSF dynamics abnormalities. Patients with multiple abnormal biomarkers (≥3) or a combination of abnormal MRI and ophthalmic biomarkers are likely to have intracranial hypertension and should be managed promptly.
Background Cerebrospinal fluid (CSF) leak following spinal surgery is a relatively common surgica... more Background Cerebrospinal fluid (CSF) leak following spinal surgery is a relatively common surgical complication. A disturbance in the underlying CSF dynamics could be the causative factor in a small group of patients with refractory CSF leaks that require multiple surgical repairs and prolonged hospital admission. Methods A retrospective case series of patients with persistent post spinal surgery CSF leak referred to the hydrocephalus service for continuous intracranial pressure (ICP) monitoring. Patients' notes were reviewed for medical history, ICP data, radiological data, and subsequent management and outcome. Results Five patients (two males/three females, mean age, 35.4 years) were referred for ICP monitoring over a 12month period. These patients had prolonged CSF leak despite multiple repair attempts 252 ± 454 days (mean ± SD). On ICP monitoring, all five patients had abnormal results, with the mean ICP 8.95 ± 4.41 mmHg. Four had abnormal pulse amplitudes, mean 6.15 mmHg ± 1.22 mmHg. All five patients underwent an intervention. Three patients underwent insertion of ventriculoperitoneal (VP) shunts. One patient had venous sinus stent insertion and one patient underwent medical management with acetazolamide. All five of the patients' CSF leak resolved post intervention. The mean time to resolution of CSF leak post intervention was 10.8 ± 12.9 days. Conclusions Abnormal cerebrospinal fluid dynamics could be the underlying factor in patients with a persistent and treatment-refractory CSF leak post spinal surgery. Treatments aimed at lowering ICP may be beneficial in this group of patients. Whether abnormal pressure and dynamics represent a pre-existing abnormality or is induced by spinal surgery should be a subject of further study.
OBJECTIVEChronic ventriculomegaly in the absence of raised intracranial pressure (ICP) is a known... more OBJECTIVEChronic ventriculomegaly in the absence of raised intracranial pressure (ICP) is a known entity in adult hydrocephalus practice. The natural history and indication for treatment is, however, poorly defined. A highly heterogeneous group, some adults with ventriculomegaly are asymptomatic, while others have life-threatening deteriorations. The authors hypothesized that the various presentations can be subtyped and represent different stages of decompensation. A cluster analysis was performed on a cohort of patients with chronic ventriculomegaly with the aim of elucidating typical clinical characteristics and outcomes in chronic ventriculomegaly in adults.METHODSData were collected from 79 patients with chronic ventriculomegaly referred to a single center, including demographics, presenting symptoms, and 24-hour ICP monitoring (ICPM). A statistical cluster analysis was performed to determine the presence of subgroups.RESULTSFour main subgroups and one highly dissimilar group were identified. Patients with ventriculomegaly commonly have a perinatal event followed by one of four main presentations: 1) incidental ventriculomegaly with or without headache; 2) highly symptomatic presentation (including reduced consciousness) and raised ICP; 3) early presenting with symptoms of headache and nausea (with abnormal pulsatility); and 4) late presenting with features common to normal pressure hydrocephalus. Each symptomatic group has characteristic radiological features, ICPM, and responses to treatment.CONCLUSIONSCluster analysis has identified subgroups of adult patients with ventriculomegaly. Such groups may represent various degrees of decompensation. Surgical interventions may not be equally effective across the subgroups, presenting an avenue for further research. The identified subtypes provide further insight into the natural history of this lesser studied form of hydrocephalus.
BACKGROUND: Complex hydrocephalus affecting lateral and fourth ventricles separately is occasiona... more BACKGROUND: Complex hydrocephalus affecting lateral and fourth ventricles separately is occasionally managed with cerebrospinal fluid diversion via supratentorial and infratentorial ventricular catheters. The optimal configuration to reduce complications is currently unknown in adults. We describe a consistently similar clinical presentation of patients with complex hydrocephalus and a fourth ventricle separately drained by infratentorial shunt insertion.-METHODS: This was a retrospective single-center case series. Medical notes were reviewed for clinical presentation, brain imaging, and neurophysiologic tests results. All patients underwent intracranial pressure monitoring (ICPM). Outcomes were determined by ventricular appearance on brain imaging computed tomography and symptomatic improvements postoperatively.-RESULTS: Five adult patients referred to the hydrocephalus service had separate infratentorial and supratentorial shunt systems. A common clinical presentation was observed, including lower motor neuron facial palsy (confirmed with electrophysiology), ophthalmoplegia, dysarthria, impaired gait headache, and nausea. We refer to this as transtentorial distortion syndrome. Twenty-four-hour ICPM demonstrated clear low pressures. All patients underwent shunt revision connecting the transtentorial shunts via a Y-connector and the addition of a distal valve. All subjects had improved ventricular appearance on computed tomography scans post revision, and normalization of ICPM was observed. In the follow-up period of 6 months, no patient required further shunt revision.-CONCLUSION: To prevent transtentorial distortion syndrome, supratentorial and infratentorial shunt constructs in adults with encysted fourth ventricles should be similar to the shunt systems widely known in the pediatric population with Dandy-Walker syndrome (i.e., joint output to a single valve distal to the connection of the 2 proximal drainage catheters).
Background Idiopathic Normal Pressure Hydrocephalus (NPH) is a condition of the elderly treated b... more Background Idiopathic Normal Pressure Hydrocephalus (NPH) is a condition of the elderly treated by ventriculoperitoneal shunt (VP) insertion. A subset of NPH patients respond only temporarily to shunt insertion despite low valve opening pressure. This study aims to describe our experience of patients who benefit from further CSF drainage by adding adjustable anti-gravity valves and draining CSF at ultra-low pressure. Methods Single-centre retrospective case series of patients undergoing shunt valve revision from an adjustable differential pressure valve with fixed antigravity unit to a system incorporating an adjustable gravitational valve (Miethke proSA). Patients were screened from a database of NPH patients undergoing CSF diversion over 10 consecutive years (April 2008-April 2018). Clinical records were retrospectively reviewed for interventions and clinical outcomes. Results Nineteen (10F:9M) patients underwent elective VP shunt revision to a system incorporating an adjustable gravitational valve. Mean age 77.1 7.1 years (mean SD). Eleven patients (58%) showed significant improvement in walking speed following shunt revision. Fourteen patients/carers (74%) reported subjective improvements in symptoms following shunt revision. Conclusions Patients presenting symptoms relapse following VP shunting may represent a group of patients with ultra-lowpressure hydrocephalus, for whom further CSF drainage may lead to improvement in symptoms. These cases may benefit from shunt revision with an adjustable gravitational valve, adjustment of which can lead to controlled siphoning of CSF and drain CSF despite ultra-low CSF pressure.
I n recent years, intracranial pressure (ICP) monitoring has gained an important role in the diag... more I n recent years, intracranial pressure (ICP) monitoring has gained an important role in the diagnosis and treatment of patients affected by chronic cerebrospinal fluid (CSF) dynamics disturbances, such as normal pressure hydrocephalus (NPH), idiopathic intracranial hypertension (IIH), Chiari malformation type I (CM-I), and various forms of hydrocephalus. 1 Compared to patients in the acute setting, patients with chronic CSF dynamics disorders are most commonly mobile and provide a unique opportunity to study the changes of ICP and pulse amplitude (PA) in different body positions. Most studies on ICP monitoring describe ICP in the supine position, despite the fact that humans spend most of their time in an upright posture. Better insight into the ABBREVIATIONS CM-I = Chiari malformation type I; CSF = cerebrospinal fluid; ICP = intracranial pressure; IIH = idiopathic intracranial hypertension; NHNN = The National Hospital for Neurology and Neurosurgery; NPH = normal pressure hydrocephalus; PA = pulse amplitude.
Papilloedema is a clinical manifestation of chronically raised ICP, often seen in idiopathic intr... more Papilloedema is a clinical manifestation of chronically raised ICP, often seen in idiopathic intracranial hypertension (IIH). However, the extent of intracranial hypertension required to produce papilloedema is not known. We compare ICP values in IIH patients who developed papilloedema and those who did not. We aim identify a pathological ICP threshold predictive of the development of papilloedema in IIH patients. Materials and Methods Single centre cohort of IIH patients (2006-2016) who underwent 24-hour ICP monitoring (ICPM) and ophthalmology assessments, prior to intervention. Papilloedema was graded according to the Frisén scale. An unpaired t-test compared 24-hour ICPM between papilloedema and no-papilloedema groups. Fisher's exact test was used to determine predictive value of ICP. Results Thirty-six patients with IIH (35 F: 1M), mean age 32.5 ± 9.49 years (mean ± SD). Patients with papilloedema had a mean median 24-hour ICP of 10.4 ± 5.32 mmHg (n=25), significantly higher than the group without papilloedema 6.31 ± 3.30 mmHg (n=11) (p <0.05). The papilloedema group were exposed to higher pressures (10mmHg) for 30 minutes or more. Using 24-hour median ICP of 10 mmHg as a minimum cutoff predictive value gives a specificity=91%, sensitivity=48%, PPV=92% and NPV=44% of detecting papilloedema. Conclusions A 24-hour ICP of 10 mmHg or more is a good predictor for papilloedema and reflects a pathological threshold. The range varied widely suggesting papilloedema can occur at even lower pressures. These results are consistent with emerging evidence suggest that pathologically 'high' 24 hrs ICP is lower than previously quoted.
The ever present need to balance over drainage with under drainage in hydrocephalus has required ... more The ever present need to balance over drainage with under drainage in hydrocephalus has required innovations including adjustable valves with antigravity devices. These are activated in the vertical position to prevent siphoning. We describe a group of bedridden patients who presented with unexplained under drainage caused by activation of antigravity shunt components produced by peculiar head/body position. Retrospective single centre case series of hydrocephalus patients, treated with ventriculo-peritoneal (VP) shunt insertion between April 2014 - February 2016. These patients presented with clinical and radiological under drainage syndrome. Medical notes were reviewed for clinical picture and outcome. Radiological studies were reviewed assessing shunt placement and ventricular size. Seven patients presented with clinical and radiological under drainage syndrome. A consistent posturing of long term hyper-flexion of the neck whilst lying supine was observed. All patients had similar shunt construct (adjustable Miethke ProGAV valve and shunt assistant anti-gravity component). In each of those patients a hypothesis was formulated that neck flexion was activating the shunt assistance anti-gravity component in supine position. Five patients underwent shunt revision surgery removing the shunt assistant device from the cranium and adding an anti-gravity component to the shunt system at the chest. One had the shunt assistant completely removed and one patient was managed conservatively with mobilisation. All patients had clinical and radiological improvement. Antigravity shunt components implanted cranially in bedridden hydrocephalus patients will produce underdrainage due to head flexion induced anti-gravity device activation. In these patients, anti-gravity devices should be placed at the chest. Alternatively, special nursing attention should be paid to head-trunk angle.
Journal of Neurosurgical Anesthesiology, Dec 3, 2019
Background: Patients with normal pressure hydrocephalus (NPH) are often elderly, frail and affect... more Background: Patients with normal pressure hydrocephalus (NPH) are often elderly, frail and affected by multimorbidity. Treatment is surgical with cerebrospinal diversion shunts. The selection of patients that are of an acceptable level of risk to be treated surgically has been a matter of debate for years and has deprived some patients of life-changing surgery. The aim of this service evaluation was to investigate the preoperative risk factors and early postoperative morbidity of patients with NPH using a standardized postoperative survey. Materials and Methods: Consecutive NPH patients admitted for neurosurgical management of NPH between May 2017 and May 2018 were included in this prospective service evaluation. In addition to the collection of traditional outcome measures, the cardiac version of the Postoperative Morbidity Survey (C-POMS) was conducted on postoperative days 4, 7, and 10 to identify postoperative morbidity. Results: Eighty-eight patients (63 males, age mean±SD, 75±7 y) underwent 106 surgical procedures (61 lumbar drains, 45 ventriculoperitoneal shunts). There was no 30-day mortality and no unexpected return to the operating room or admission to intensive care unit. There was 1 conservatively managed surgical complication. On postoperative day 4, the C-POMS identified no postoperative morbidity in 72% of the patients, and mild morbidity (postoperative nausea and mobility issues) in 28%. There was a delay in discharge in 50% of the patients with no postoperative morbidity on day 4, highlighting areas of our service requiring improvement. Conclusions: Early postoperative outcomes of NPH patients are good after both ventriculoperitoneal shunt insertion and lumbar drainage. This evaluation provides initial evidence on the utility of the C-POMS as a service evaluation tool in the standardized assessment postoperative outcomes in neurosurgery patients.
Treatment for a large symptomatic syrinx associated with a Chiari 1 is predominately surgical, vi... more Treatment for a large symptomatic syrinx associated with a Chiari 1 is predominately surgical, via a foramen magnum decompression (FMD), with the aim to normalise cerebrospinal fluid (CSF) movement. Whilst theories of underlying hyperdynamic states in Chiari 1 and Syringomyelia exist, to date there is no effective medical treatment to reverse Syringomyelia. A 17-year-old female was referred with a seven-month history of gradually progressive impaired temperature sensation in her left upper limb. She had also been concomitantly diagnosed with thyrotoxicosis. Magnetic resonance imaging (MRI) confirmed a Chiari 1 with a large syrinx. The patient preferred to avoid surgery in the first instance. She underwent treatment for her thyrotoxicosis. The eightmonth, 20-and 36-month follow-up MRI scans demonstrated a gradual resolution of the Chiari 1 malformation and the syrinx. Whilst there have been reports of Chiari 1 malformation association with hyperthyroidism, this is the first report describing syrinx resolution following treatment of thyrotoxicosis. Hyperdynamic circulation can result in syrinx formation through various mechanisms. We hypothesise that the treatment of thyrotoxicosis resulted in normalisation of CSF pulse amplitude and subsequent syrinx resolution. Hyperthyroidism evaluation may be explored in studies of CM1 and Syrinx or other CSF disorders.
Introduction Tinnitus is a symptom commonly associated with idiopathic intracranial hypertension ... more Introduction Tinnitus is a symptom commonly associated with idiopathic intracranial hypertension (IIH) that can have a profound effect on quality of life. We aim to determine tinnitus symptom response after dural venous sinus stenting (DVSS) or CSF diversion with a shunt, in patients with both pulsatile (PT) and non-pulsatile tinnitus (NPT). Methods Single-centre cohort of IIH patients (2006-2016) who underwent 24-h ICP monitoring (ICPM). An un-paired t test compared ICP and pulse amplitude (PA) values in IIH patients with PT vs. NPT. Results We identified 59 patients with IIH (56 F:3 M), mean age 32.5 ± 9.49 years, 14 of whom suffered from tinnitus. Of these 14, seven reported PT and seven reported NPT. Patients with tinnitus had a mean 24-h ICP and PA of 9.09 ± 5.25 mmHg and 6.05 ± 1.07 mmHg respectively. All 7 patients with PT showed symptom improvement or resolution after DVSS (n = 4), secondary DVSS (n = 2) or shunting (n = 1). In contrast, of the 7 with NPT, only 1 improved post intervention (DVSS), despite 2 patients having shunts and 5 having DVSS. Conclusions NPT and PT were equally as common in our group of IIH patients. DVSS appears to be an effective management option for IIH patients with a clear history of pulsatile tinnitus. However, non-pulsatile tinnitus was more persistent and did not respond well to either DVSS or CSF diversion.
BACKGROUND CONTEXT: Cerebrospinal fluid (CSF) leak following spinal surgery is a relatively commo... more BACKGROUND CONTEXT: Cerebrospinal fluid (CSF) leak following spinal surgery is a relatively common surgical complication. A small group of CSF leak patients require multiple surgical repairs and prolonged hospital admission. Spinal CSF leaks are usually classically associated with symptoms of low intracranial pressure (ICP). However, there is a paucity of literature investigating the associated CSF dynamics. PURPOSE: Scientific investigation of persistent spinal CSF leak post-surgery. STUDY DESIGN/SETTING: Retrospective cohort study. PATIENT SAMPLE: Patients with persistent CSF leak referred to the hydrocephalus service in our unit for intracranial pressure monitoring. OUTCOME MEASURES: Physiological and clinical outcome. METHODS: Retrospective case series study of patients with persistent CSF leak referred to the hydrocephalus service in our unit for intracranial pressure monitoring. Medical notes were reviewed for clinical presentation, management and outcome. Images were reviewed and ICP data were analysed. All patients underwent continuous ICP monitoring using Spiegelberg ICP bolts. RESULTS: Three patients had spinal fixation surgery, complicated by prolonged CSF leaks (mean of 56 days). Each patient required two reexploration spinal surgeries and multiple lumbar drains insertions prior to 24 hours of ICP monitoring. All patients were shown to have raised ICP (>15.2 mmHg). One patient underwent a right transverse venous sinus stent insertion. Two patients underwent insertion of ventriculoperitoneal shunts (VPS). All three had resolution of their CSF leaks immediately post intervention. CONCLUSIONS: Our results suggest that abnormal cerebrospinal fluid dynamics should be explored in patients with persistent CSF leak post spinal surgery. Whether abnormal pressure and dynamics represent a pre-existing abnormality or is induced by spinal surgery should be subject for further studies. CONFLICTS OF INTEREST: Nil. FUNDING SOURCES: Nil.
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
The optimal management of patients with ventriculoperitoneal or lumboperitoneal shunts undergoing... more The optimal management of patients with ventriculoperitoneal or lumboperitoneal shunts undergoing abdominal or pelvic surgery for unrelated reasons is often unclear due to the paucity of guidelines in this field. In this review, we outline key issues in managing these patients. Specifically, we address issues relating to pre-operative planning, avoidance of shunt-related complications such as infection and malfunction, and specific management of neurological symptoms in the post-operative period. A retrospective study was carried out analysing correspondence between general surgeons and a specialist hydrocephalus unit over a 4-year period relating to management of patients with ventriculoperitoneal and lumboperitoneal shunts undergoing abdominal or pelvic surgery. A literature review was carried out to identify available evidence in this field. 30 queries from general surgeons were identified comprising 12 main themes. 16 relevant publications were identified. We summarised these to answer these queries. The management of shunted patients may present challenges and uncertainties in an abdominal or pelvic surgery setting. This paper provides guidelines and clarity in this field by discussing and summarising reported data in the literature.
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Raised white cell count (WCC) in lumbar CSF is a commonly used marker of meningitis. The effect o... more Raised white cell count (WCC) in lumbar CSF is a commonly used marker of meningitis. The effect of cranial neurosurgery per se on lumbar WCC is not established. At this single centre, many patients undergo ICPM followed by lumboperitoneal shunt (LPS), with lumbar CSF WCC samples taken during insertion. We aimed to determine the effect of ICP bolt insertion on lumbar CSF WCC. We undertook a retrospective analysis of lumbar CSF samples in patients who had recently undergone 24-h ICPM. Thirty-three patients (16F:7M) aged 43.31 ± 12.1 years (mean ± SD) had lumbar CSF samples after ICPM. Fourteen had CSF sampled within 6 weeks and 19 after 6 weeks of ICPM. Twenty-five samples were taken during LPS insertion, 5 during lumbar drainage/puncture and 3 during LPS revision. All 33 patients were afebrile at the point of CSF sampling. The mean lumbar WCC within 6 weeks of ICPM was significantly higher than the mean lumbar WCC after 6 weeks, being 15.4 ± 18.0 and 2.32 ± 1.79 cells/microlitre respectively respectively. There was no significant increase in RBC. In patients with raised CSF WCC, 60% of raised WCC were predominantly lymphoctyes and 40% predominantly neutrophils. Only one patient grew an organism (S. aureus). We conclude that lumbar CSF WCC can be raised following minor intracranial surgery, despite no clinical sign of infection. We caution against using lumbar CSF WCC values independently as the only marker of infection following neurosurgery.
Background Elective intraparenchymal intracranial pressure (ICP) monitoring is useful for the dia... more Background Elective intraparenchymal intracranial pressure (ICP) monitoring is useful for the diagnosis and treatment of hydrocephalus and cerebrospinal fluid (CSF) disorders. This retrospective study analyzes median ICP and pulse amplitude (PA) recordings in neurosurgically naïve patients undergoing elective ICP monitoring for suspected CSF disorders. Methods Retrospective review of prospectively collated database of neurosurgically naïve patients undergoing elective ICP monitoring for suspected hydrocephalus and CSF disorders. Following extraction of the median ICP and PA values (separated into all, day and night time recordings), principal component analysis (PCA) was performed to identify the principal factors determining the spread of the data. Exploratory comparisons and correlations of ICP and PA values were explored, including by post hoc diagnostic groupings and age. Results A total of 198 patients were identified in six distinct diagnostic groups (n = 21-47 in each). The PCA suggested that there were two main factors accounting for the spread in the data, with 61.4% of the variance determined largely by the PA and 33.0% by the ICP recordings. Exploratory comparisons of PA and ICP between the diagnostic groups showed significant differences between the groups. Specifically, significant differences were observed in PA between a group managed conservatively and the Chiari/ syrinx, IIH, and NPH/LOVA groups and in the ICP between the conservatively managed group and high-pressure, IIH, and low-pressure groups. Correlations between ICP and PA revealed some interesting trends in the different diagnostic groups and correlations between ICP, PA, and age revealed a decreasing ICP and increasing PA with age. Conclusions This study provides insights into hydrodynamic disturbances in different diagnostic groups of patients with CSF hydrodynamic disorders. It highlights the utility of analyzing both median PA and ICP recordings, stratified into day and night time recordings.
Objective To evaluate the utility of brain MRI and ophthalmic biomarkers for the prediction of in... more Objective To evaluate the utility of brain MRI and ophthalmic biomarkers for the prediction of intracranial hypertension, we have studied the association between 6 biomarkers and 24-hour intracranial pressure (ICP) monitoring results in 45 patients.Methods This single-center observational study includes patients who underwent 24-hour ICP monitoring, brain MRI (within 3 months), and ophthalmic assessment (during ICP monitoring). Six biomarkers were investigated: pituitary gland shape, vertical tortuosity of the optic nerve, distension of the optic nerve sheath, optic disc protrusion (MRI), papilledema (slit lamp biomicroscopy), and spontaneous venous pulsations (SVP, infrared video recordings).Results Forty-five patients (mean age 39 ± 14 years, 38 women) met the inclusion criteria. All 6 biomarkers had a significant association with 24-hour ICP. Concave pituitary gland was observed with moderately elevated median ICP. Protrusion of the optic disc (MRI), papilledema, and absence of SVP were associated with the highest median ICP values. Twenty patients had raised ICP (median 24-hour ICP >5.96 mm Hg, cutoff obtained through Youden index calculation). Patients with all normal biomarkers had normal median ICP in 94% (standard error 6%) of the cases. All patients with ≥3 abnormal biomarkers had intracranial hypertension. The combination of at least 1 abnormal biomarker in MRI and ophthalmic assessments was highly suggestive of intracranial hypertension (area under the curve 0.94, 95% confidence interval 0.93–0.94)Conclusions Brain MRI and ophthalmic biomarkers can noninvasively guide the management of patients with suspected CSF dynamics abnormalities. Patients with multiple abnormal biomarkers (≥3) or a combination of abnormal MRI and ophthalmic biomarkers are likely to have intracranial hypertension and should be managed promptly.
Background Cerebrospinal fluid (CSF) leak following spinal surgery is a relatively common surgica... more Background Cerebrospinal fluid (CSF) leak following spinal surgery is a relatively common surgical complication. A disturbance in the underlying CSF dynamics could be the causative factor in a small group of patients with refractory CSF leaks that require multiple surgical repairs and prolonged hospital admission. Methods A retrospective case series of patients with persistent post spinal surgery CSF leak referred to the hydrocephalus service for continuous intracranial pressure (ICP) monitoring. Patients' notes were reviewed for medical history, ICP data, radiological data, and subsequent management and outcome. Results Five patients (two males/three females, mean age, 35.4 years) were referred for ICP monitoring over a 12month period. These patients had prolonged CSF leak despite multiple repair attempts 252 ± 454 days (mean ± SD). On ICP monitoring, all five patients had abnormal results, with the mean ICP 8.95 ± 4.41 mmHg. Four had abnormal pulse amplitudes, mean 6.15 mmHg ± 1.22 mmHg. All five patients underwent an intervention. Three patients underwent insertion of ventriculoperitoneal (VP) shunts. One patient had venous sinus stent insertion and one patient underwent medical management with acetazolamide. All five of the patients' CSF leak resolved post intervention. The mean time to resolution of CSF leak post intervention was 10.8 ± 12.9 days. Conclusions Abnormal cerebrospinal fluid dynamics could be the underlying factor in patients with a persistent and treatment-refractory CSF leak post spinal surgery. Treatments aimed at lowering ICP may be beneficial in this group of patients. Whether abnormal pressure and dynamics represent a pre-existing abnormality or is induced by spinal surgery should be a subject of further study.
OBJECTIVEChronic ventriculomegaly in the absence of raised intracranial pressure (ICP) is a known... more OBJECTIVEChronic ventriculomegaly in the absence of raised intracranial pressure (ICP) is a known entity in adult hydrocephalus practice. The natural history and indication for treatment is, however, poorly defined. A highly heterogeneous group, some adults with ventriculomegaly are asymptomatic, while others have life-threatening deteriorations. The authors hypothesized that the various presentations can be subtyped and represent different stages of decompensation. A cluster analysis was performed on a cohort of patients with chronic ventriculomegaly with the aim of elucidating typical clinical characteristics and outcomes in chronic ventriculomegaly in adults.METHODSData were collected from 79 patients with chronic ventriculomegaly referred to a single center, including demographics, presenting symptoms, and 24-hour ICP monitoring (ICPM). A statistical cluster analysis was performed to determine the presence of subgroups.RESULTSFour main subgroups and one highly dissimilar group were identified. Patients with ventriculomegaly commonly have a perinatal event followed by one of four main presentations: 1) incidental ventriculomegaly with or without headache; 2) highly symptomatic presentation (including reduced consciousness) and raised ICP; 3) early presenting with symptoms of headache and nausea (with abnormal pulsatility); and 4) late presenting with features common to normal pressure hydrocephalus. Each symptomatic group has characteristic radiological features, ICPM, and responses to treatment.CONCLUSIONSCluster analysis has identified subgroups of adult patients with ventriculomegaly. Such groups may represent various degrees of decompensation. Surgical interventions may not be equally effective across the subgroups, presenting an avenue for further research. The identified subtypes provide further insight into the natural history of this lesser studied form of hydrocephalus.
BACKGROUND: Complex hydrocephalus affecting lateral and fourth ventricles separately is occasiona... more BACKGROUND: Complex hydrocephalus affecting lateral and fourth ventricles separately is occasionally managed with cerebrospinal fluid diversion via supratentorial and infratentorial ventricular catheters. The optimal configuration to reduce complications is currently unknown in adults. We describe a consistently similar clinical presentation of patients with complex hydrocephalus and a fourth ventricle separately drained by infratentorial shunt insertion.-METHODS: This was a retrospective single-center case series. Medical notes were reviewed for clinical presentation, brain imaging, and neurophysiologic tests results. All patients underwent intracranial pressure monitoring (ICPM). Outcomes were determined by ventricular appearance on brain imaging computed tomography and symptomatic improvements postoperatively.-RESULTS: Five adult patients referred to the hydrocephalus service had separate infratentorial and supratentorial shunt systems. A common clinical presentation was observed, including lower motor neuron facial palsy (confirmed with electrophysiology), ophthalmoplegia, dysarthria, impaired gait headache, and nausea. We refer to this as transtentorial distortion syndrome. Twenty-four-hour ICPM demonstrated clear low pressures. All patients underwent shunt revision connecting the transtentorial shunts via a Y-connector and the addition of a distal valve. All subjects had improved ventricular appearance on computed tomography scans post revision, and normalization of ICPM was observed. In the follow-up period of 6 months, no patient required further shunt revision.-CONCLUSION: To prevent transtentorial distortion syndrome, supratentorial and infratentorial shunt constructs in adults with encysted fourth ventricles should be similar to the shunt systems widely known in the pediatric population with Dandy-Walker syndrome (i.e., joint output to a single valve distal to the connection of the 2 proximal drainage catheters).
Background Idiopathic Normal Pressure Hydrocephalus (NPH) is a condition of the elderly treated b... more Background Idiopathic Normal Pressure Hydrocephalus (NPH) is a condition of the elderly treated by ventriculoperitoneal shunt (VP) insertion. A subset of NPH patients respond only temporarily to shunt insertion despite low valve opening pressure. This study aims to describe our experience of patients who benefit from further CSF drainage by adding adjustable anti-gravity valves and draining CSF at ultra-low pressure. Methods Single-centre retrospective case series of patients undergoing shunt valve revision from an adjustable differential pressure valve with fixed antigravity unit to a system incorporating an adjustable gravitational valve (Miethke proSA). Patients were screened from a database of NPH patients undergoing CSF diversion over 10 consecutive years (April 2008-April 2018). Clinical records were retrospectively reviewed for interventions and clinical outcomes. Results Nineteen (10F:9M) patients underwent elective VP shunt revision to a system incorporating an adjustable gravitational valve. Mean age 77.1 7.1 years (mean SD). Eleven patients (58%) showed significant improvement in walking speed following shunt revision. Fourteen patients/carers (74%) reported subjective improvements in symptoms following shunt revision. Conclusions Patients presenting symptoms relapse following VP shunting may represent a group of patients with ultra-lowpressure hydrocephalus, for whom further CSF drainage may lead to improvement in symptoms. These cases may benefit from shunt revision with an adjustable gravitational valve, adjustment of which can lead to controlled siphoning of CSF and drain CSF despite ultra-low CSF pressure.
I n recent years, intracranial pressure (ICP) monitoring has gained an important role in the diag... more I n recent years, intracranial pressure (ICP) monitoring has gained an important role in the diagnosis and treatment of patients affected by chronic cerebrospinal fluid (CSF) dynamics disturbances, such as normal pressure hydrocephalus (NPH), idiopathic intracranial hypertension (IIH), Chiari malformation type I (CM-I), and various forms of hydrocephalus. 1 Compared to patients in the acute setting, patients with chronic CSF dynamics disorders are most commonly mobile and provide a unique opportunity to study the changes of ICP and pulse amplitude (PA) in different body positions. Most studies on ICP monitoring describe ICP in the supine position, despite the fact that humans spend most of their time in an upright posture. Better insight into the ABBREVIATIONS CM-I = Chiari malformation type I; CSF = cerebrospinal fluid; ICP = intracranial pressure; IIH = idiopathic intracranial hypertension; NHNN = The National Hospital for Neurology and Neurosurgery; NPH = normal pressure hydrocephalus; PA = pulse amplitude.
Papilloedema is a clinical manifestation of chronically raised ICP, often seen in idiopathic intr... more Papilloedema is a clinical manifestation of chronically raised ICP, often seen in idiopathic intracranial hypertension (IIH). However, the extent of intracranial hypertension required to produce papilloedema is not known. We compare ICP values in IIH patients who developed papilloedema and those who did not. We aim identify a pathological ICP threshold predictive of the development of papilloedema in IIH patients. Materials and Methods Single centre cohort of IIH patients (2006-2016) who underwent 24-hour ICP monitoring (ICPM) and ophthalmology assessments, prior to intervention. Papilloedema was graded according to the Frisén scale. An unpaired t-test compared 24-hour ICPM between papilloedema and no-papilloedema groups. Fisher's exact test was used to determine predictive value of ICP. Results Thirty-six patients with IIH (35 F: 1M), mean age 32.5 ± 9.49 years (mean ± SD). Patients with papilloedema had a mean median 24-hour ICP of 10.4 ± 5.32 mmHg (n=25), significantly higher than the group without papilloedema 6.31 ± 3.30 mmHg (n=11) (p <0.05). The papilloedema group were exposed to higher pressures (10mmHg) for 30 minutes or more. Using 24-hour median ICP of 10 mmHg as a minimum cutoff predictive value gives a specificity=91%, sensitivity=48%, PPV=92% and NPV=44% of detecting papilloedema. Conclusions A 24-hour ICP of 10 mmHg or more is a good predictor for papilloedema and reflects a pathological threshold. The range varied widely suggesting papilloedema can occur at even lower pressures. These results are consistent with emerging evidence suggest that pathologically 'high' 24 hrs ICP is lower than previously quoted.
The ever present need to balance over drainage with under drainage in hydrocephalus has required ... more The ever present need to balance over drainage with under drainage in hydrocephalus has required innovations including adjustable valves with antigravity devices. These are activated in the vertical position to prevent siphoning. We describe a group of bedridden patients who presented with unexplained under drainage caused by activation of antigravity shunt components produced by peculiar head/body position. Retrospective single centre case series of hydrocephalus patients, treated with ventriculo-peritoneal (VP) shunt insertion between April 2014 - February 2016. These patients presented with clinical and radiological under drainage syndrome. Medical notes were reviewed for clinical picture and outcome. Radiological studies were reviewed assessing shunt placement and ventricular size. Seven patients presented with clinical and radiological under drainage syndrome. A consistent posturing of long term hyper-flexion of the neck whilst lying supine was observed. All patients had similar shunt construct (adjustable Miethke ProGAV valve and shunt assistant anti-gravity component). In each of those patients a hypothesis was formulated that neck flexion was activating the shunt assistance anti-gravity component in supine position. Five patients underwent shunt revision surgery removing the shunt assistant device from the cranium and adding an anti-gravity component to the shunt system at the chest. One had the shunt assistant completely removed and one patient was managed conservatively with mobilisation. All patients had clinical and radiological improvement. Antigravity shunt components implanted cranially in bedridden hydrocephalus patients will produce underdrainage due to head flexion induced anti-gravity device activation. In these patients, anti-gravity devices should be placed at the chest. Alternatively, special nursing attention should be paid to head-trunk angle.
Journal of Neurosurgical Anesthesiology, Dec 3, 2019
Background: Patients with normal pressure hydrocephalus (NPH) are often elderly, frail and affect... more Background: Patients with normal pressure hydrocephalus (NPH) are often elderly, frail and affected by multimorbidity. Treatment is surgical with cerebrospinal diversion shunts. The selection of patients that are of an acceptable level of risk to be treated surgically has been a matter of debate for years and has deprived some patients of life-changing surgery. The aim of this service evaluation was to investigate the preoperative risk factors and early postoperative morbidity of patients with NPH using a standardized postoperative survey. Materials and Methods: Consecutive NPH patients admitted for neurosurgical management of NPH between May 2017 and May 2018 were included in this prospective service evaluation. In addition to the collection of traditional outcome measures, the cardiac version of the Postoperative Morbidity Survey (C-POMS) was conducted on postoperative days 4, 7, and 10 to identify postoperative morbidity. Results: Eighty-eight patients (63 males, age mean±SD, 75±7 y) underwent 106 surgical procedures (61 lumbar drains, 45 ventriculoperitoneal shunts). There was no 30-day mortality and no unexpected return to the operating room or admission to intensive care unit. There was 1 conservatively managed surgical complication. On postoperative day 4, the C-POMS identified no postoperative morbidity in 72% of the patients, and mild morbidity (postoperative nausea and mobility issues) in 28%. There was a delay in discharge in 50% of the patients with no postoperative morbidity on day 4, highlighting areas of our service requiring improvement. Conclusions: Early postoperative outcomes of NPH patients are good after both ventriculoperitoneal shunt insertion and lumbar drainage. This evaluation provides initial evidence on the utility of the C-POMS as a service evaluation tool in the standardized assessment postoperative outcomes in neurosurgery patients.
Treatment for a large symptomatic syrinx associated with a Chiari 1 is predominately surgical, vi... more Treatment for a large symptomatic syrinx associated with a Chiari 1 is predominately surgical, via a foramen magnum decompression (FMD), with the aim to normalise cerebrospinal fluid (CSF) movement. Whilst theories of underlying hyperdynamic states in Chiari 1 and Syringomyelia exist, to date there is no effective medical treatment to reverse Syringomyelia. A 17-year-old female was referred with a seven-month history of gradually progressive impaired temperature sensation in her left upper limb. She had also been concomitantly diagnosed with thyrotoxicosis. Magnetic resonance imaging (MRI) confirmed a Chiari 1 with a large syrinx. The patient preferred to avoid surgery in the first instance. She underwent treatment for her thyrotoxicosis. The eightmonth, 20-and 36-month follow-up MRI scans demonstrated a gradual resolution of the Chiari 1 malformation and the syrinx. Whilst there have been reports of Chiari 1 malformation association with hyperthyroidism, this is the first report describing syrinx resolution following treatment of thyrotoxicosis. Hyperdynamic circulation can result in syrinx formation through various mechanisms. We hypothesise that the treatment of thyrotoxicosis resulted in normalisation of CSF pulse amplitude and subsequent syrinx resolution. Hyperthyroidism evaluation may be explored in studies of CM1 and Syrinx or other CSF disorders.
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Papers by Claudia Craven