Cerebrospinal Fluid Pressure Monitoring Research Articles

Anesthesia management for thoracoscopic resection of a huge intrathoracic meningocele: a case report

BackgroundDiagnosed intrathoracic meningocele is an uncommon complication of neurofibromatosis type 1. We report an anesthesia management for a rare case undergoing thoracoscopic resection of a huge intrathoracic meningocele.Case presentationA 51-year-old woman was scheduled for thoracoscopic meningectomy under general anesthesia. We monitored intrathecal pressure during anesthesia to prevent a decrease in intrathecal pressure. During surgery, the intrathecal pressure occasionally increased by around 5 cmH2O immediately after the insertion of the drainage tube and occasionally decreased by up to 10 cmH2O during the careful slow aspiration of the cerebrospinal fluid (CSF). The pressure rapidly recovered after the interruption of the procedures. She was discharged on postoperative day 4 without major complications.ConclusionsThe CSF pressure was fluctuated by procedures during thoracoscopic resection of a huge meningocele. A CSF pressure monitoring was useful to detect the sudden change of CSF pressure immediately, which can cause intracranial hemorrhage.

Optic Nerve Head and Retinal Changes in Idiopathic Intracranial Hypertension: Correlation with Short-Term Cerebrospinal Fluid Pressure Monitoring.

We aimed to assess the status of the optic nerve and retina by optical coherence tomography (OCT) in a group of patients with idiopathic intracranial hypertension (IIH) on the basis of dynamic changes in intracranial pressure. This observational and cross-sectional study included patients affected by idiopathic intracranial hypertension with papilledema (IIHWP) and patients with idiopathic intracranial hypertension without papilledema (IIHWOP). All participants underwent an OCT examination of the macula and optic nerve head. Parameters related to intracranial pressure, including cerebrospinal fluid (CSF) opening pressure (oCSFp), CSF mean pressure (mCSFp), and pulse wave amplitude (PWA), were included in the analysis. Out of the 22 subjects enlisted for the study, a total of 16 patients suggestive of IIH were finally enrolled. Papilledema was detected in nine subjects (56.2%) and seven patients were affected by IIHWOP (43.7%). The OCT examination showed a higher mean RNFL thickness in IIHWP patients in comparison to IIHWOP in both eyes (p < 0.05 and p < 0.01, respectively). Intracranial pressure (ICP) measurements showed that IIHWP had higher values of oCSFp, mCSFp, and PWA compared to IIHWOP (p = 0.0001, p = 0.0001, and p = 0.0001, respectively). In addition, ICP parameters significantly correlated with RNFL. Clinical parameters suggestive of idiopathic intracranial hypertension are associated with retina and optic nerve OCT parameters. OCT is a useful tool to detect these alterations in a non-invasive fashion.

Papilloedema: a highly specific predictor of raised intracranial pressure in a complex neurosurgical paediatric cohort.

Papilloedema is recognised as an indicator of raised intracranial pressure, although there is a paucity of literature describing the utility of fundoscopy in screening for raised ICP in children with craniofacial synostosis, particularly young children. We sought to investigate the association of optic disc morphology with ICP in children, and to define the sensitivity and specificity of papilloedema as a clinical indicator of raised ICP and determine if age, or underlying conditions impact the findings. Retrospective analysis of all patients undergoing ICP monitoring at a designated paediatric neurosurgical and craniofacial unit in the United Kingdom between October 2009 and October 2018. The fundoscopy findings and ICP monitoring data were analysed for 31 children with craniosynostosis and 29 children without craniosynostosis. All children who had papilloedema had raised ICP confirmed with monitoring. Across the 60-patient cohort, confirmed papilloedema on fundoscopy had Positive Predictive Value (PPV) of 1.00, Negative Predictive Value (NPV) of 0.64 with sensitivity 48% and specificity 100% for the presence of raised ICP (p = < 0.0001). In the craniosynostosis group, PPV was 1.00, NPV was 0.39, sensitivity 48% and specificity 100% (p = < 0.03). There is no correlation between severity of optic disc swelling using Frisen grading and elevation of ICP. Age did not affect the presence of papilloedema in those with raised ICP. The presence of papilloedema is a strong indicator of raised ICP in a child, regardless of underlying aetiology. Detailed fundoscopy can prevent the need for further investigations including imaging-related radiation and invasive CSF pressure monitoring.

Pressure-Volume Relationships in the Spinal Canal and Potential Neurological Complications After Epidural Fluid Injections.

High-volume fluid injections into the spinal canal may lead to severe neurological complications. But when anatomical or pathological conditions in the spinal canal are unfavorable, even small volume epidural injections can cause dangerously high epidural, subarachnoid, and intracranial pressures or pressure gradients. Data obtained from the scientific literature and direct clinical observation are used to derive a first-order approximation of epidural, subarachnoid, and intracranial pressure responses to epidural fluid injections. Maximum allowable fluid volumes for single or multiple divided fluid injections over time are calculated. In the presence of spinal pathology, 10 ml of fluids may increase epidural pressure to >100 mmHg. Injection speed >4 ml per second may also generate dangerously high intraspinal and intracranial pressures. Intermitted bolus injections provide limited protection, but intraspinal pressures may rise very fast when a critical total injected volume is reached. Potential complications of increased intracranial pressures or large pressure waves include nerve palsies, tinnitus, blindness, stroke, and death. Spinal injections or endoscopy should be performed in an awake responsive patient or with direct cerebrospinal fluid pressure monitoring. A set of guidelines for epidural fluid management is given.

Intraoperative Monitoring of CSF Pressure in Patients with Degenerative Cervical Myelopathy (COMP-CORD Study): A Prospective Cohort Study.

Degenerative cervical myelopathy (DCM) is hallmarked by spinal canal narrowing and related cord compression and myelopathy. Cerebrospinal fluid (CSF) pressure dynamics are likely disturbed due to spinal canal stenosis. The study aimed to investigate the diagnostic value of continuous intraoperative CSF pressure monitoring during surgical decompression. This prospective single center study (NCT02170155) enrolled DCM patients who underwent surgical decompression between December 2019 and May 2021. Data from n = 17 patients were analyzed and symptom severity graded with the modified Japanese Orthopedic Score (mJOA). CSF pulsations were continuously monitored with a lumbar intrathecal catheter during surgical decompression. Mean patient age was 62 ± 9 years (range 38-73; 8 female), symptoms were mild-moderate in most patients (mean mJOA 14 ± 2, range 10-18). Measurements were well tolerated without safety concerns. In 15/16 patients (94%), CSF pulsations increased at the time of surgical decompression. In one case, responsiveness could not be evaluated for technical reasons. Unexpected CSF pulsation decrease was related to adverse events (i.e., CSF leakage). Median CSF pulsation amplitudes increased from pre-decompression (0.52 mm Hg, interquartile range [IQR] 0.71) to post-decompression (0.72 mm Hg, IQR 0.96; p = 0.001). Mean baseline CSF pressure increased with lower magnitude than pulsations, from 9.5 ± 3.5 to 10.3 ± 3.8 mm Hg (p = 0.003). Systematic relations of CSF pulsations were confined to surgical decompression, independent of arterial blood pressure (p = 0.927) or heart rate (p = 0.102). Intraoperative CSF pulsation monitoring was related to surgical decompression while in addition adverse events could be discerned. Further investigation of the clinical value of intraoperative guidance for decompression in complex DCM surgery is promising.

Cervical Vestibular Evoked Myogenic Potentials in Idiopathic Intracranial Hypertension.

Idiopathic intracranial hypertension (IIH) is raised intracranial pressure without any identifiable etiology. The inner ear structures are susceptible to cerebrospinal fluid (CSF) pressure changes because of connections between the CSF space and the labyrinth to explain the audiovestibular symptoms, such as pulsatile tinnitus or dizziness, reported in 50% to 60% of these patients. The aim of this study was to investigate the vestibular functions using cervical vestibular evoked myogenic potentials (cVEMPs) in IIH. cVEMPs were recorded in 30 patients with IIH before lumbar puncture. Thirty healthy volunteers constituted the control group. The latencies of peaks p13 and n23 and peak-to-peak amplitude of p13-n23 were measured. Responses were gathered bilaterally from all healthy controls. In 30 patients with IIH, 49 responses could be gathered from 60 tests (81.7%). The potential was absent bilaterally in five and unilaterally in one patient. When recorded, the latency and amplitude values of the responses of the patients were not significantly different from the healthy controls (P > 0.005). A correlation between CSF pressure and response persistence could not be determined. cVEMPs are affected in patients with IIH and the main finding is the absence of the responses. Increased intracranial pressure causing sound transmission changes within the inner ear can affect the saccular afferents and may end up with absent responses on air-conducted cVEMP recordings. To comment on the correlation between the CSF pressure and cVEMP changes, successive cVEMP recordings with longitudinal CSF pressure monitoring seem necessary.

Study protocol for an observational study of cerebrospinal fluid pressure in patients with degenerative cervical myelopathy undergoing surgical deCOMPression of the spinal CORD: the COMP-CORD study

IntroductionDegenerative cervical myelopathy (DCM) is a disabling spinal disorder characterised by sensorimotor deficits of upper and lower limbs, neurogenic bladder dysfunction and neuropathic pain. When suspected, cervical MRI helps to...

Transcranial Doppler for Monitoring and Evaluation of Idiopathic Intracranial Hypertension.

Background Idiopathic intracranial hypertension (IIH) is a disorder of unknown origin, characterized by features of raised intracranial pressure (ICP). Existing literature is inconclusive about the role of transcranial Doppler (TCD) in the management of IIH. Objective To study the TCD changes in IIH patients, pre- and post-cerebrospinal fluid (CSF) drainage. Materials and Methods This was a prospective study, conducted between July 2017 and December 2019, in a tertiary care referral center in South India. Sixteen consecutive patients, suspected to have IIH, underwent magnetic resonance imaging ofthe brain, a baseline TCD, and lumbar puncture with CSF drainage and pressure monitoring. Post-CSF drainage, TCD was repeated and mean flow velocities, peak systolic velocities, end-diastolic velocities, and pulsatility index (PI), in the middle cerebral artery (MCA), vertebral artery, and basilar artery (BA) were noted. Thirteen patients had elevated CSF pressure, and fulfilled the diagnostic criteria for IIH. These patients were included in the final analysis and pre- and post-CSF drainage TCD blood flow velocities and PI were compared. Results The mean age of study participants was 29.92 ± 6.92 years. There was a significant reduction in the cerebral flow velocities in bilateral MCA, after CSF drainage and normalization of ICP. Flow velocities in posterior circulation and PI in MCA, PCA, and BA showed an insignificant reduction. Two patients, who did not show any reduction in flow velocities after CSF drainage, developed optic atrophy on follow-up. Conclusion TCD-derived systolic blood flow velocities can be used in the management and follow-up of patients with IIH.

Application of tap test and continuous monitoring of intracranial pressure in the treatment of idiopathic normal pressure hydrocephalus

Objective To reveal the value of cerebrospinal fluid (CSF) tap test and continuous monitoring of intracranial pressure in the treatment of idiopathic normal pressure hydrocephalus (iNPH). Methods Clinical data of 253 patients with iNPH admitted to Department of Neurosurgery, Renji Hospital, School of Medicine, Shanghai Jiaotong University from January 2013 to June 2018 were retrospectively analyzed. Patients with positive results of tap test underwent shunt operation. One month after 12 hours of continuous CSF pressure monitoring test, patients with negative results of tap test underwent shunt operation. We evaluated the clinical and prognostic value of RAP [correlation coefficient (R) between AMP amplitude (A) and mean pressure (P)] index in the diagnosis and treatment of iNPH. Results A total of 189 patients underwent shunt operation out of 253 patients. Among them, 161 patients showed improvement post surgery and 28 patients reported no improvement. The overall surgical rate was 74.7% and the surgical efficiency was 85.2 %. The tap test was positive in 160 patients and 149 patients underwent shunt operation. There were 147 cases with improvement of clinical symptoms after shunting while 2 cases had no improvement. The tap test was negative in 93 cases and 40 accepted 12 hours of continuous CSF pressure monitoring test and shunt operation. Improvement was reported in 12 after shunting and 4 remained unchanged among 16 patients with RAP index>0.6, while 2 were improved after operation and 22 were unchanged out of 24 patients with RAP index≤0.6. The outcome difference between those 2 groups (RAP index >0.6 and RAP index ≤0.6) of patients (χ2=24.350, P<0.01). Conclusion The RAP index >0.6 could also be used as an effective supplement of surgical indication for therapeutic effect of shunting in patients with iNPH.It has clinical application value. Key words: Hydrocephalus, normal pressure; Ventriculoperitoneal shunt; Intracranial pressure; Cerebrospinal fluid tap test; Prognostic value

Sphenopalatine ganglion block for post-dural puncture headache after invasive cerebrospinal fluid pressure monitoring. Case report

ABSTRACT BACKGROUND AND OBJECTIVES: Post-dural puncture headache is a common complication in neuraxial anesthesia and lumbar puncture diagnostic procedures. The pathogenesis of the headache is thought to be due to a leak of cerebrospinal fluid from the puncture site that exceeds the rate of cerebrospinal fluid production, causing a downward traction of the meninges and vasodilation of the meningeal vessels mediated by the autonomous nervous system. Nowadays, the conservative treatment involves hydration, and the use of caffeine, analgesics, hydrocortisone, gabapentin, and theophylline. However, an autologous epidural blood patch is considered the definitive treatment for post-dural puncture headache and has an efficacy of up to 75%. Since this procedure comes with intrinsic risks, an alternative is the sphenopalatine ganglion block. CASE REPORT: We describe a case report using a sphenopalatine ganglion block to treat post-dural puncture headache in a patient submitted to cerebrospinal fluid pressure monitoring with a subarachnoidal catheter inserted with a low-gauge needle. CONCLUSION: This is the first case report of a post-dural puncture headache caused by a subarachnoid monitoring catheter successfully treated with sphenopalatine ganglion block. This technique can be a non-invasive option in the management of post-dural puncture headache, which requires more study to evaluate its efficacy and safety.

Cerebrospinal Fluid Pressure-Related Features in Chronic Headache: A Prospective Study and Potential Diagnostic Implications.

Objective: To identify the pressure-related features of isolated cerebrospinal fluid hypertension (ICH) in order to differentiate headache sufferers with ICH from those with primary headache disorder.Methods: In this prospective study, patients with refractory chronic headaches and suspected of having cerebrospinal fluid-pressure elevation without papilledema or sixth nerve palsy, together with controls, underwent 1-h lumbar cerebrospinal fluid pressure monitoring via a spinal puncture needle.Results: We recruited 148 consecutive headache patients and 16 controls. Lumbar cerebrospinal fluid pressure monitoring showed high pressure and abnormal pressure pulsations in 93 (63 %) patients with headache: 37 of these patients with the most abnormal pressure parameters (opening pressure above 250 mm H2O, mean pressure 301 mm H2O, mean peak pressure 398 mm H2O, and severe abnormal pressure pulsations) had the most severe headaches and associated symptoms (nocturnal headache, postural headache, transient visual obscuration); 56 patients with the less abnormal pressure parameters (opening pressure between 200 and 250 mm H2O, mean pressure 228 mm H2O, mean peak pressure 316 mm H2O, and abnormal pressure pulsations) had less severe headaches and associated symptoms.Conclusions: Nocturnal and postural headache, and abnormal pressure pulsations are the more common pressure-related features of ICH in patients with chronic headache. Abnormal pressure pulsations may be considered a marker of ICH in chronic headache.

Vascular parkinsonism or idiopathic NPH? New insights from CSF pressure analysis.

Differential diagnosis between vascular parkinsonism (VP) and idiopathic normal pressure hydrocephalus (iNPH) is particularly challenging due to similar clinical and neuroradiological features. The objective of this study is to differentiate VP with radiological evidence of ventricular enlargement (REVE) from iNPH on the basis of cerebrospinal fluid (CSF) hydrodynamics. CSF pressure components were investigated in patients with a clinical diagnosis of VP and REVE. Data of eight patients (seven men; age 76±3.9years; disease duration 26.5±15.6months) were evaluated. CSF opening pressure values were normal in all patients. Also, mean CSF pressure values during short-term monitoring were normal, except in one patient. Four out of the eight patients had raised values of pulse wave amplitude (PWA) during the opening phase (mean±SD 57.1±19.9mmH2O), meanwhile during short-term monitoring, seven out of the eight patients showed raised values of mean PWA (76.8±23mmH2O). We found that most of patients with clinical characteristics of VP and REVE showed elevated PWA during the short-term monitoring of CSF pressure as observed in iNPH patients. Patients clinically identified as VP may be part of the clinical spectrum of iNPH.

Perioperative continuous cerebrospinal fluid pressure monitoring in patients with spontaneous cerebrospinal fluid leaks.

Elevated intracranial pressure (ICP) is an inciting factor for cerebrospinal fluid (CSF) leaks and can be measured by CSF pressure (CSFP) monitoring. Current CSFP literature is limited to the assessments of opening pressure. This study reinvestigates a previously discussed monitoring approach that evaluates continuous CSFP parameters, physiologic measurements, and treatment outcomes in patients undergoing endoscopic repair of spontaneous CSF leaks. Retrospective review of patients undergoing endoscopic endonasal repair of spontaneous CSF leaks. All participants had a lumbar catheter placed for 24-hour continuous preoperative pressure monitoring, and 24 hours of continuous monitoring starting 48 hours after repair. In addition to patient characteristics, mean and peak CSFP, pulse waveform amplitudes (PWAs), and related parameters were calculated. Twenty-five patients underwent monitoring between 2004 and 2013, with a mean follow-up of 526 days. The mean age was 49.2 years, the mean body mass index (BMI) 38.5, and 8 of 25 (32%) had obstructive sleep apnea. Although mean CSFP and PWA decreased after the repair, mean peak CSFP increased by 1.56 cmH2O (1.15 mmHg). Six patients (24%) had elevation in their CSFP >25 cmH2O (18.4 mmHg) for a minimum of 4% of the recording time. Based on their continuous pressure monitoring data, 9 patients (36%) underwent treatment for high ICP, either with acetazolamide or a ventricular shunt. There were no CSF leak recurrences. Continuous perioperative CSFP monitoring provides valuable insight into multiple physiologic parameters. Systematic continuous CSFP monitoring can identify individuals in need of ICP-lowering therapy, possibly improving the outcomes in CSF leak repair surgeries.

Association between Physiologic Parameters and Anatomic Location in Spontaneous Cerebrospinal Fluid Leaks

Objectives: Although a relationship between elevated cerebrospinal fluid (CSF) pressure and spontaneous CSF leaks has been reported, analyses by anatomic sub-site are lacking. This study seeks to elucidate the association between physiologic parameters and CSF leak location. Methods: Prospective case series of patients undergoing endoscopic endonasal repair of spontaneous CSF leak between 2004 and 2013. All participants had a lumbar drain placed for 24-hour continuous preoperative pressure monitoring, and 24 hours of continuous monitoring starting 48 hours after the repair. In addition to patient characteristics, mean and peak CSF pressures by anatomic location were calculated and compared. Results: Twenty-five patients underwent perioperative CSF pressure monitoring, with a mean follow-up of 526 days. Nine patients had CSF leaks along the cribiform plate, 4 in the ethmoid roof, 8 in the sphenoid, 2 in the posterior table of the frontal sinus, and 2 with multiple leaks. Patients with cribiform leaks had the lowest mean body mass index (BMI) and prevalence of obstructive sleep apnea (22.2%), while those with multiple sites of leak had the highest mean BMI and prevalence of obstructive sleep apnea (50%). Patients with frontal sinus leaks had the highest postoperative mean (14.47 mmHg) and peak (42.5 mmHg) CSF pressures, while ethmoid roof had the lowest mean (0.43 mmHg) and peak (16.45 mmHg) CSF pressures. Conclusions: CSF pressure and other physiologic characteristics differ among patients with spontaneous CSF leaks by anatomic location. Understanding these differences may enable treatment approaches tailored by leak site, thereby improving repair outcomes.

Idiopathic intracranial hypertension in pediatric population: Case series from India

Idiopathic intracranial hypertension (IIH) is a well described entity in adults. In pediatric age group the presentation of disease can vary depending on the age of patients and is less frequently reported. The aim of this study is to describe the clinical features, investigations, treatment and outcome of IIH in pediatric population (age <18 years). This retrospective hospital based study was carried out on 25 children with diagnosis of IIH based on modified Dandys criteria. Their clinical, investigation, treatment, outcome and follow-up for 2 year period were analyzed. Out of the 25 children, the youngest child was 4-month-old infant. The commonest symptom was headache (76%) followed by vomiting and papilledema (72%). The mean cerebrospinal fluid (CSF) pressure was 330 mm of H 2 O. In Infants irritability and bulging anterior fontanelle was seen. A total of 24 patients showed a complete resolution of symptom. None of patient had recurrence over a period of 2 years follow-up. IIH can present at any age group. This is the largest series of IIH reported in pediatric population in India. The clinical features are similar to adult patients except in infants. Absence of papilledema does not exclude the diagnosis of IIH. CSF pressure monitoring is needed in suspected cases of IIH. Early and prompt treatment can prevent deficits.

Paraplegia prevention branches: A new adjunct for preventing or treating spinal cord injury after endovascular repair of thoracoabdominal aneurysms

In this report, we describe a technique that could potentially be used for both prevention and treatment of spinal cord ischemia (SCI) in endovascular repair of thoracoabdominal aneurysms. This technique involves using a specially designed endograft with side branches (paraplegia prevention branches [PPBs]), which are left patent to perfuse the aneurysmal sac and any associated lumbar or intercostal arteries in the early postoperative period. The use of PPBs with this technique is feasible and allows for a temporary controlled endoleak that may be useful for preventing or reversing spinal cord injury. This technique may be considered as an adjunct to the more standard perioperative physiological manipulations such as permissive hypertension and spinal fluid drainage.

Evaluation of the cerebrovascular pressure reactivity index using non-invasive finapres arterial blood pressure

A pressure reactivity index (PRx) can be assessed in patients with continuous monitoring of arterial blood pressure (ABP) and intracranial pressure (ICP) as a moving correlation coefficient between slow fluctuations of these two signals within a low frequency bandwidth. The study aimed to investigate whether the invasive ABP monitoring can be replaced with non-invasive measurement of ABP using a Finapres plethysmograph (fABP) to calculate the fPRx. There is a well-defined group of patients, suffering from hydrocephalus and undergoing CSF pressure monitoring, which may benefit from such a measurement. 41 simultaneous day-by-day monitoring of ICP, ABP and fABP were performed for about 30 min in 10 head injury patients. A Bland–Altman assessment for agreement was used to compare PRx and fPRx calculations. Performance metrics and the McNemary test were used to determine whether fPRx is sensitive enough to distinguish between functioning and disturbed cerebrovascular pressure reactivity. The fPRx correlated with PRx (RSpearman = 0.92, p < 0.001; bias = −0.04; lower and upper limits of agreement: −0.26 and 0.17, respectively). The fPRx distinguished between active and passive reactivity in more than 89% cases. The fPRx can be used with care for assessment of cerebrovascular reactivity in patients for whom invasive ABP measurement is not feasible. The fPRx is sensitive enough to distinguish between functional and deranged reactivity.

Intracranial hypertension, headache and obesity: Insights from magnetic resonance venography

Idiopathic intracranial hypertension without papilloedema (IIHWOP) is uncommon, accounting for, at most, 5% of patients with IIH evaluated by neuroophthalmologists (1). In contrast to patients with IIH and papilloedema, patients with IIHWOP are less obese, have lower cerebrospinal fluid pressures, and are more likely to have non-organic visual loss (1). This entity is perhaps more readily diagnosed among headache specialists than neuro-ophthalmologists and is suspected in obese women with intractable or chronic daily headaches (2). The integral relationship between the central venous system and intracranial pressure has been emphasised over the past several years with the discovery of venous sinus abnormalities in patients with IIH (3). Morphological irregularities and abnormal pressure gradients within the transverse sinuses are well described. In most cases, transverse venous sinus stenosis appears to be a result of high intracranial pressure rather than its cause (4). The transverse sinuses are asymmetric in most individuals and a unilateral hypoplastic sinus is considered a normal variant. However, bilateral transverse sinus stenosis (BTSS) may be associated with intracranial hypertension. In this issue of Cephalalgia, Bono and colleagues studied 98 patients with chronic migraine and chronic tension type headache using magnetic resonance venography and 1-h continuous lumbar CSF pressure monitoring (5). Their findings are notable in several respects. Strikingly, their patients were obese, regardless of CSF pressure status. Patients with normal CSF pressure (Group 1) were less overweight than in the groups with either intermittently (Group 2) or consistently (Group 3) elevated CSF pressure, and some patients in Group 1 had a normal body mass index (BMI), but overall this cohort was overweight. There was no different in BMI between subjects in Groups 2 and 3. Obesity is a risk factor for both IIH and the development of chronic daily headache (6). Although there was a statistically significant difference in both mean CSF pressure and opening pressure between the three groups, only some of the patients in Group 3 met criteria for the diagnosis of IIH by current standards (7). Pressures between 201–249mm CSF are non-diagnostic (8). BTSS has been noted in a majority of patients with IIH by various investigators. It is less commonly encountered in a typical practice setting, even in patients with papilloedema. The high prevalence of BTSS in this cohort is perhaps attributable to the imaging technique used, which the investigators previously found to have a very high detection rate of transverse sinus stenosis (three dimensional phase contrast images with 15 cm/s velocity encoding). Conventional MR venography is often performed using two dimensional time of flight, and the images are likely subjected to less scrutiny in the practice setting than the research setting. All subjects in Groups 2 and 3 had BTSS, whereas only four of 54 patients in group 1 had BTSS. As previously noted, unilateral transverse sinus stenosis was not associated with abnormal intracranial pressure. One-hour monitoring showed mean pressures that were consistently higher than the opening pressure in all groups. The importance of this finding cannot be overemphasised. An isolated CSF pressure measurement is but a ‘snapshot in time’ and may be spuriously high or low, depending on the situation and technique employed. Prolonged monitoring also revealed B-waves in Groups 2 and 3; B-waves are frequently recorded with increased intracranial pressure of various aetiologies, although there is far greater experience defining pressure wave abnormalities with intracranial pressure monitoring systems than with lumbar recording methods. Digre and colleagues (1) found that treatment of patients with IIHWOP with agents conventionally

Abnormal pressure waves in headache sufferers with bilateral transverse sinus stenosis

Bilateral transverse sinus stenosis (BTSS) has been reported to be associated with idiopathic intracranial hypertension without papilloedema in headache sufferers. To test the accuracy of short-term cerebrospinal fluid (CSF) pressure monitoring through a lumbar needle for detection of elevated intracranial pressure in headache sufferers with BTSS, we prospectively performed lumbar puncture in order to measure lumbar CSF opening pressures and to monitor, for 1 h, the CSF pressure in 48 consecutive headache sufferers with BTSS and in 50 consecutive headache sufferers with normal appearance of transverse sinuses or stenosis of one transverse sinus. Of the 48 headache sufferers with BTSS, 18 (37.5%) had elevated CSF opening pressure and abnormal pressure waveforms, but short-term CSF pressure monitoring revealed abnormal pressure waves associated with elevated mean CSF pressure also in 26 (86.6%) out of 30 patients who had normal opening pressures. None of the 50 headache sufferers with normal appearance of transverse sinuses or stenosis of one transverse sinus had abnormal pressure waves and elevated CSF pressures. In this study, short-term CSF pressure monitoring through a lumbar needle revealed abnormal pressure waves and elevated mean CSF pressures in the majority of headache sufferers with BTSS who had normal CSF opening pressures. These findings demonstrate the accuracy of short-term CSF pressure monitoring through a lumbar needle in estimating CSF pressure; they also highlight that a single-spot opening pressure measurement has a low accuracy for recognition of increased intracranial pressure in headache sufferers with BTSS.

Perioperative Continuous Cerebrospinal Fluid Pressure Monitoring in Patients with Spontaneous Cerebrospinal Fluid Leaks: Presentation of a Novel Technique

A few studies have used direct measurements of cerebral spinal fluid pressure (CSFP) using either lumbar punctures or pressure transducers to evaluate CSFP elevations as a potential etiology in patients with spontaneous CSF leaks. Limitations of these techniques include positional variation, inadequate duration of measurement, and insufficient analysis of waveforms. We propose a novel technique for more accurate measurement of CSFP in patients with spontaneous CSF leaks. Patients with spontaneous CSF rhinorrhea had a lumbar catheter placed for 24-hour CSFP recording before and 72 hours after their endoscopic surgical repair. Heart rate, electrocardiogram, respirations, and oxygen saturation are recorded in addition to CSFP. Mean CSFP as well as the pulse waveform amplitude were calculated. Twelve patients with spontaneous CSF rhinorrhea underwent continuous CSFP monitoring. Seven patients had elevations in their CSFP of >25 cm H(2)O for at least 4% of their recording time during their continuous monitoring. Nine patients had significant oxygen desaturations associated with elevated CSFP. Pulse waveform amplitudes could average 20 cm H(2)O over several minutes in patients with mean CSFP of <10 cm H(2)O. Perioperative CSFP monitoring provides continuous data including mean and transient elevations in CSFP that can be correlated to other measurements such as oxygen saturation. This data may more accurately identify those CSF leak patients with elevated CSFP as well as correlate these elevations to prognostic clinical information that may improve treatment and outcome after their surgical repair.