Dynamic interaction between cerebrospinal fluid and sinovenous pressure in idiopathic intracranial hypertension: a case report

BACKGROUND

Idiopathic intracranial hypertension (IIH) is a common neurosurgical condition, and the exact pathophysiology remains elusive. Cerebral sinovenous stenosis (CSS) and the resultant decreased venous outflow have been labelled as a potential contributors to the pathophysiology of IIH. We describe the effect of cerebrospinal fluid (CSF) drainage on sinovenous pressure in a patient with IIH and a radiographic evidence of CSS.

CASE DESCRIPTION

A patient in their 40s with a diagnoses of IIH and imaging finding of focal stenosis of the distal left transverse sinus. To assess the nature of the stenosis, we performed venous sinus pressure monitoring with concurrent CSF drainage (5 ml at one minute intervals) through a lumbar drain with continuous mean sinovenous pressures recording. We observed a progressive decline in the pressure recording while draining CSF, after draining 40 ml of CSF, the final pressure gradient recording of the TS-SS trans-stenotic was (7 mm Hg from 27 mm Hg), mean SSS pressure (37 mm Hg from 60 mm Hg), and mean TS pressure (35 mm Hg from 56 mm Hg). The mean SS pressure remained relatively unperturbed.

CONCLUSION

Our findings indicate that the cerebral sinovenous pressure response to CSF removal generally conforms to a monophasic exponential decay model.

Transverse Venous Sinus Stenosis in Patients With Nasal Cerebrospinal Fluid Leak and Idiopathic Intracranial Hypertension

OBJECTIVE

Spontaneous nasal cerebrospinal fluid (CSF) leaks are frequently linked to idiopathic intracranial hypertension (IIH). The objectives of our study were: (1) to determine the rate of transverse venous sinus stenosis (TVSS) in patients with spontaneous nasal CSF leak and in patients with IIH without CSF (controls), and (2) to study the correlation between spontaneous nasal CSF leak and brain imaging features.

STUDY DESIGN

A multicenter retrospective case-control study.

SETTING

Six French tertiary hospitals.

METHODS

Patients with spontaneous nasal CSF leaks and patients with IIH without nasal CSF leaks (controls) were included. The transverse venous sinus patency was analyzed by magnetic resonance imaging to identify possible stenosis or hypoplasia.

RESULTS

Thirty-two patients with spontaneous nasal CSF leaks and 32 controls were included. TVSS was significantly more frequent in patients with spontaneous nasal CSF leaks than in controls (p = .029). Univariate analysis indicated that TVSS (odds ratio, OR: 4.2; 95% confidence interval, CI [1.352-14.915]; p = .017) and arachnoid granulations (OR: 3; 95% CI [1.065-8.994]; p = .042) were risk factors for spontaneous nasal CSF leak. In multivariate analysis, TVSS and arachnoid granulations were independent risk factors of nasal CSF leak (OR: 5.577, 95% CI [1.485-25.837], p = .016; and OR: 4.35, 95% CI [1.234-17.756], p = .029, respectively).

CONCLUSION

This multicenter case-control study shows that TVSS is an independent risk factor for CSF leak in patients with IIH. Stenosis management by interventional radiology may be proposed postoperatively to increase the success of IIH surgical treatment or preoperatively to reduce the need for surgery.

Cranial decompression and expansion surgery for the treatment of refractory idiopathic intracranial hypertension: case report and systematic review

OBJECTIVE

The purpose of this study is to systematically review the literature on the clinical outcomes following different surgical techniques in patients with refractory idiopathic intracranial hypertension (IIH).

BACKGROUND

IIH is a condition characterised by increased cranial pressure (ICP) in the absence of an intracranial lesion that does not adequately respond to different medical and surgical therapies. Cranial decompression or expansion surgeries are a last resort therapy for patients with refractory IIH.

METHODS

A systematic literature search of the databases of PubMed, Embase and Medline from inception to 2019 was performed. Searches were limited to the English language and to clinical studies. Studies were included if clinical outcomes following different cranial decompression or expansion techniques were reported. We also add one case of our own experience with performing a bilateral frontoparietal expansion craniotomy and subtemporal craniectomy.

RESULTS

Five manuscripts, describing 38 procedures, met the inclusion criteria. Thirty-one patients were female (82%). The mean age was 26.2 years. The techniques studied included subtemporal craniectomy (27/38, 71%), internal cranial expansion (10/38, 26%), and cranial morcellation decompression (1/38, 3%). Thirty-five patients presented with headaches of which 17 noted postoperative improvement or resolution (49%). Visual deficits were documented in 30 patients and 25 reported postoperative improvement (83%). Papilledema disappeared in 23 of 32 patients with this sign at presentation (72%). In our patient, symptoms completely resolved postoperatively and a 6% increase in intracranial volume was measured.

CONCLUSIONS

Cranial vault decompression or expansion surgeries may be an effective last resort therapy for patients with refractory IIH. These surgeries expand the intracranial volume, and thus may normalise ICP, leading to clinical improvement.

Degree of basal cisterns compression predicting mortality and functional outcome after craniotomy and primary decompressive craniectomy in acute subdural hematoma population

OBJECTIVES

The compression of basal cisterns on CT is one of the signs of intracranial hypertension in TBI population. This study evaluates the relationship between the degree of basal cisterns effacement and outcomes in aSDH population.

METHODS

The study includes prospectively collected data from 290 patients who underwent osteoplastic craniotomy (OC) or primary decompressive craniectomy (pDC) for aSDH from 2016 to 2021. Univariate and multivariate regression analyses were performed to evaluate the association of baseline characteristics and extent of basal cisterns compression on pre-operative and post-operative CT scans with the outcomes at the time of discharge. Outcomes were dichotomized into mortality (and unfavourable (GOS 1-3 vs GOS 4-5). The degree of cisternal compression was evaluated using the cisternal effacement score of perimesencephalic and quadrigeminal cisternal components. Critical thresholds associated with the outcomes were calculated.

RESULTS

Age and pre-/post-operative degree of cisternal compression were the strongest independent predictors of intrahospital mortality in a whole sample and separately in OC and pDC subgroups. The unfavourable outcome was independently predicted by age, pre-/post-operative status of cisternal compression and initial GCS. Critical thresholds associated with the mortality and poor functional outcome were, respectively, age ≥ 70 (OR 3.14 [CI 95% 1.82-5.46], p < 0.001) and ≥ 67 (OR 3.87 [CI 95% 2.33-6.54], p < 0.001), pre-operative cisternal effacement score ≥ 9 (OR 6.39 [CI 95% 3.62-11.53], p < 0.001) and ≥ 7 (OR 4.93 [CI 95% 2.96-8.38], p < 0.001), post-operative cisternal effacement score ≥ 6 (OR 20.6 [CI 95% 10.08-45.10], p < 0.001) and ≥ 3 (OR 7.47 [CI 95% 3.87-15.73], p < 0.001) and initial GCS ≤ 8 (OR 0.24 [CI 95% 0.13-0.43], p < 0.001 and OR 0.12 [CI 95% 0.07-0.21], p < 0.001).

CONCLUSIONS

After adjusting for baseline characteristics, age and degree of cisternal compression remained the independent predictors of mortality, whereas unfavourable outcomes were associated with age, cisternal obliteration and GCS on presentation.

Impact of early external ventricular drainage on functional outcome after traumatic brain injury: a bicentric retrospective cohort analysis

PURPOSE

Several studies have confirmed that external ventricular drain decreases intracranial pressure (ICP) after traumatic brain injury (TBI). Considering its impact on ICP control and cerebral waste metabolites clearance, timing of external ventricular drain (EVD) insertion could improve CSF drainage efficiency. The aim of the study was to evaluate the impact of early EVD versus a later one on the 3-month outcome.

METHODS

For this retrospective cohort study conducted in two regional trauma-center (Caen CHU Côte de Nacre and Beaujon Hospital) between May 2011 and March 2019, all patients with intracranial hypertension following TBI and treated with EVD were included. We defined the early EVD by drainage within the 24 h of the hospital admission and the late EVD insertion by drainage beyond 24 h. A poor outcome was defined as a Glasgow Outcome Scale of one or two at 3 months.

RESULTS

Among the cohort of 671 patients, we analyzed 127 patients. Sixty-one (48.0%) patients had an early insertion of EVD. In the early EVD group, the mean time to insertion was 10 h versus 55 h in the late EVD group. Among the analyzed patients, 69 (54.3%) had a poor outcome including 39 (63.9%) in the early group and 30 (45.5%) in the later one. After adjustment on prognostic factors, early EVD insertion was not associated with a decrease in a poor outcome at 3-months (OR = 1.80 [0.73-4.53]).

CONCLUSION

Early insertion of EVD (<24 h) for intracranial hypertension after TBI was not associated with improved outcome at 3 months.

Oxycephaly-systematic review, case presentation, and diagnostic clarification

PURPOSE

Oxycephaly is a specific phenotype of multi-suture craniosynostosis that is often misrepresented. This study aims to review the relevant literature, clarify the diagnostic criteria, and present an alternate approach to its management.

METHODS

Published literature regarding oxycephaly was reviewed from 1997, when the largest series was published, until 2022. All cases at a single institution were then retrospectively reviewed.

RESULTS

Over the last 25 years, four studies met the inclusion criteria, none of which specifically defined oxycephaly. One case, in one study, was potentially consistent with the phenotype. An institutional review yielded two patients who met the original diagnostic criteria set forth by Renier and Marchac. Both patients had unexplained speech delays, mild retinal nerve fiber layer thickening, and diffuse inner table scalloping, along with the characteristic oxycephalic phenotype. One patient also had a direct intracranial pressure (ICP) measurement of 25 mmHg, and the other had a Chiari I malformation. Both were treated with posterior vault distraction osteogenesis (PVDO) to alleviate the cephalo-cranial disproportion while simultaneously allowing for turricephaly correction.

CONCLUSIONS

Oxycephaly presents with late onset multi-suture fusion. Patients have patent sutures at birth. Midface hypoplasia and known syndromic associations are absent. Patients demonstrate supraorbital recession, an obtuse fronto-nasal angle, and turricephaly without substantial brachycephaly. Over 60% of patients have symptomatic ICP elevation, the presentation of which ranges from headaches to rapidly progressive blindness. This rare form of craniosynostosis is particularly virulent and likely often missed due to diagnostic ambiguity and its relatively mild phenotype.

Diagnostic Value of the Combination of Ultrasonographic Optic Nerve Sheath Diameter and Width of Crural Cistern with Respect to the Intracranial Pressure in Patients Treated with Decompressive Craniotomy

BACKGROUND

The monitoring of intracranial pressure (ICP) and detection of increased ICP are crucial because such increases may cause secondary brain injury and a poor prognosis. Although numerous ultrasound parameters, including optic nerve sheath diameter (ONSD), width of the crural cistern (WCC), and the flow velocities of the central retinal artery and middle cerebral artery, can be measured in patients after hemicraniectomy, researchers have yet to determine which of these is better for evaluating ICP. This study aimed to analyze the correlation between ICP and ultrasound parameters and investigate the best noninvasive estimator of ICP.

METHODS

This observational study enrolled 50 patients with brain injury after hemicraniectomy from January 2021 to December 2021. All patients underwent invasive ICP monitoring with microsensor, transcranial, and ocular ultrasound postoperatively. We measured the ONSD including the dura mater (ONSDI), the ONSD excluding the dura mater, the optic nerve diameter (OND), the eyeball transverse diameter (ETD), the WCC, and the flow velocities in the central retinal artery and middle cerebral artery. Then, we calculated the ONSDI-OND (the difference between ONSDI and OND) and ONSDI/ETD (the ratio of ONSDI to ETD). Patients were divided into a normal ICP group (n = 35) and an increased ICP group (≥ 20 mm Hg, n = 15) according to the ICP measurements. Correlations were then assessed between the values of the ultrasound parameters and ICP.

RESULTS

The ONSDI, ONSDI-OND, and ONSDI/ETD were positively associated with ICP (r = 0.455, 0.482, 0.423 and p = 0.001, < 0.001, 0.002, respectively), whereas the WCC was negatively associated with ICP (r = - 0.586, p < 0.001). The WCC showed the highest predictive power for increased ICP (area under the receiver operating characteristic curve [AUC] = 0.904), whereas the ONSDI-OND and ONSDI also presented with acceptable predictive power among the ONSD-related parameters (AUC = 0.831, 0.803, respectively). The cutoff values for increased ICP prediction for ONSDI, ONSDI-OND, and WCC were 6.29, 3.03, and 3.68 mm, respectively. The AUC of the combination of ONSDI-OND and WCC was 0.952 (95% confidence interval 0.896-1.0, p < 0.001).

CONCLUSIONS

The ONSDI, ONSDI-OND, and WCC were correlated with ICP and had acceptable accuracy levels in estimating ICP in patients after hemicraniectomy. Furthermore, WCC showed a higher diagnostic value than ONSD-related parameters, and the combination of ONSDI-OND and WCC was a satisfactory predictor of increased ICP.

Comparison of Cerebral Autoregulation Above and Below the Tentorium of the Cerebellum In Neurosurgical Patients with Transtentorial ICP Gradient

INTRODUCTION

Cerebral autoregulation is an essential mechanism for maintaining cerebral blood flow stability. The phenomenon of transtentorial intracranial pressure (ICP) gradient after neurosurgical operations, complicated by edema and intracranial hypertension in the posterior fossa, has been described in clinical practice but is still underinvestigated. The aim of the study was to compare autoregulation coefficients (i.e., pressure reactivity index [PRx]) in two compartments (infratentorial and supratentorial) during the ICP gradient phenomenon.

METHODS

Three male patients, aged 24 years, 32 years, and 59 years, respectively, were involved in the study after posterior fossa surgery. Arterial blood pressure and ICP were invasively monitored. Infratentorial ICP was measured in the cerebellar parenchyma. Supratentorial ICP was measured either in the parenchyma of the cerebral hemispheres or through the external ventricular drainage. Cerebral autoregulation was evaluated by the PRx coefficient (ICM + , Cambridge, UK).

RESULTS

In all patients, ICP was higher in the posterior fossa, and the transtentorial ICP gradient in each patient was 5 ± 1.6 mm Hg, 8.5 ± 4.4 mm Hg, and 7.7 ± 2.2 mm Hg, respectively. ICP in the infratentorial space was 17 ± 4 mm Hg, 18 ± 4.4 mm Hg, and 20 ± 4 mm Hg, respectively. PRx values in the supratentorial and infratentorial spaces had the smallest difference (- 0.01, 0.02, and 0.01, respectively), and the limits of precision were 0.1, 0.2, and 0.1 in the first, second, and third patients, respectively. The correlation coefficient between the PRx values in the supratentorial and infratentorial spaces for each patient was 0.98, 0.95, and 0.97, respectively.

CONCLUSIONS

A high degree of correlation was established between the autoregulation coefficient PRx in two compartments in the presence of transtentorial ICP gradient and persistent intracranial hypertension in the posterior fossa. Cerebral autoregulation, according to the PRx coefficient in both spaces, was similar.

Emergent cerebral venous stenting: A valid treatment option for fulminant idiopathic intracranial hypertension

BACKGROUND

Fulminant idiopathic intracranial hypertension (FIIH) is characterized by rapid, severe, progressive vision loss and often treated surgically. Cerebral transverse venous stenting (CTVS) is efficacious in IIH patients, but emergent CTVS in FIIH is rarely reported. We present our experience with emergent CTVS in patients with FIIH.

METHODS

Since 01/2019, an institutional protocol allowed emergent CTVS in FIIH patients with bilateral transverse sinus stenosis and gradient pressure > 15 on digital subtraction angiography (DSA). We retrospectively analyzed a prospective registry of all IIH patients with details of neurological and neuro-ophthalmological assessments before and after treatment, and subjective assessments of headache and tinnitus were made pre-and post-procedure.

RESULTS

259 IIH patients, including 49 who underwent CTVS, were registered. Among them, five female patients met inclusion criteria for FIIH and underwent emergent CTVS. FIIH patients were younger (18.8 ± 1.64 vs 27.7 ± 4.85, p < 0.01), mean BMI was lower (30.8 ± 10.57 vs 34.6 ± 4.3, p < 0.01), and lumbar puncture opening pressure higher (454 ± vs 361 ± 99.4, p < 0.01) than that of IIH patients. They presented with acute visual loss, severe headache, papilledema, significant bilateral transverse sinus stenosis on CT-venography, and mean dominant side gradient pressure of 26.4 ± 6.2 on DSA. CTVS was performed without significant complications, resulting in remarkable improvement in headache, optical coherence tomography, and visual fields within 1 week. At 1-year follow-up (four patients) and 6-month follow-up (1 patient), there was complete resolution of papilledema and headache, and marked improvement in visual acuity.

CONCLUSIONS

In these patients, emergent-CTVS was a safe and effective treatment option for FIIH. Further evaluation is warranted.

National Trends of Cerebral Venous Sinus Stenting for the Treatment of Idiopathic Intracranial Hypertension

OBJECTIVES

Cerebral venous sinus stenting (VSS) has emerged as a new surgical procedure for the treatment of severe idiopathic intracranial hypertension (IIH), and its popularity has been anecdotally on the rise. This study explores recent temporal trends of VSS and other surgical IIH treatments in the United States.

METHODS

Adult patients with IIH were identified from the 2016-2020 National Inpatient Sample databases, and surgical procedures and hospital characteristics were recorded. Temporal trends of procedure numbers for VSS, CSF shunts, and optic nerve sheath fenestrations (ONSFs) were assessed and compared.

RESULTS

A total of 46,065 (95% CI 44,710-47,420) patients with IIH were identified, of whom 7,535 patients (95% CI 6,982-8,088) received surgical IIH treatments. VSS procedures increased 80% (150 [95% CI 55-245] to 270 [95% CI 162-378] per year, p < 0.001). Concurrently, the number of CSF shunts decreased by 19% (1,365 [95% CI 1,126-1,604] to 1,105 [95% CI 900-1,310] per year, p < 0.001), and ONSF procedures decreased by 54% (65 [95% CI 20-110] to 30 [95% CI 6-54] per year, p < 0.001).

DISCUSSION

Practice patterns for surgical IIH treatment in the United States are rapidly evolving, and VSS is becoming increasingly common. These findings highlight the urgency of randomized controlled trials to investigate the comparative effectiveness and safety of VSS, CSF shunts, ONSF, and standard medical treatments.

Cerebrospinal Fluid Diversion for Refractory Intracranial Hypertension in Traumatic Brain Injury: A Single Center Experience

BACKGROUND

Diversion of cerebrospinal fluid (CSF) is a common neurosurgical procedure for control of intracranial pressure (ICP) in the acute phase after traumatic brain injury (TBI), where medical management is insufficient. CSF can be drained via an external ventricular drain (EVD) or, in selected patients, via a lumbar (external lumbar drain [ELD]) drainage catheter. Considerable variability exists in neurosurgical practice on their use.

METHODS

A retrospective service evaluation was completed for patients receiving CSF diversion for ICP control after TBI, from April 2015 to August 2021. Patients were included whom fulfilled local criteria deeming them suitable for either ELD/EVD. Data were extracted from patient notes, including ICP values pre/postdrain insertion and safety data including infection or clinically/radiologically diagnosed tonsillar herniation.

RESULTS

Forty-one patients were retrospectively identified (ELD = 30 and EVD = 11). All patients had parenchymal ICP monitoring. Both modalities affected statistically significant decreases in ICP, with relative reductions at 1, 6, and 24 hour pre/postdrainage (at 24-hour ELD P < 0.0001, EVD P < 0.01). Similar rates of ICP control failure, blockage and leak occurred in both groups. A greater proportion of patients with EVD were treated for CSF infection than with ELD. One event of clinical tonsillar herniation is reported, which may have been in part attributable to ELD overdrainage, but which did not result in adverse outcome.

CONCLUSIONS

The data presented demonstrate that EVD and ELD can be successful in ICP control after TBI, with ELD limited to carefully selected patients with strict drainage protocols. The findings support prospective study to formally determine the relative risk-benefit profiles of CSF drainage modalities in TBI.

Comparison of extraperitoneal and intraperitoneal laparoscopic procedures for intracranial pressure increase: a prospective clinical study

OBJECTIVE

According to the literature, higher levels of both intracranial pressure (ICP) and intraabdominal pressure (IAP) are related in a way that suggests a causal relationship. An increase in ICP can cause major neurological problems both during and after laparoscopic surgery. In this study, we aimed to examine the increase in ICP between totally extraperitoneal (TEP) inguinal hernia repair and laparoscopic cholecystectomy.

PATIENTS AND METHODS

We investigated 52 individuals who underwent laparoscopic surgery for the treatment of inguinal hernia (n = 26) or had a laparoscopic cholecystectomy (n = 26). The optic nerve sheath diameter (ONSD) was assessed before the procedure (T0), 10 minutes after carbon dioxide insufflation (T1), and immediately before extubation (T2).

RESULTS

There were significant differences in the ONSD values between the two groups as a function of time (p = 0.001). In terms of ONSD, the laparoscopic cholecystectomy value (LV) group showed a greater shift from T0 to T1 and T2 than the inguinal hernia value (HV) group. At T1, the ONSD values of both groups were considerably higher than those of T0 and T2. The impact of the extraperitoneal and transperitoneal laparoscopic methods on ICP was investigated. The ONSD value reached its maximum at T1 in both groups. At all measurement periods, the ONSD values of the LV group were noticeably higher than those of the HV group.

CONCLUSIONS

The diagnostic accuracy of ONSD ultrasonography is an important approach for determining the ICP level. During the decision-making process of TEP inguinal hernia repair, this study can guide medical professionals in the evaluation of elevated ICP.

External ventricular drainage for intracranial hypertension after traumatic brain injury: is it really useful?

PURPOSES

External ventricular drainage (EVD) is frequently used to control raised intracranial pressure after traumatic brain injury. However, the available evidence about its effectiveness in this context is limited. The aim of this study is to evaluate the effectiveness of EVD to control intracranial pressure and to identify the clinical and radiological factors associated with its success.

METHODS

For this retrospective cohort study conducted in a Level 1 traumacenter in Paris area between May 2011 and March 2019, all patients with intracranial hypertension and treated with EVD were included. EVD success was defined as an efficient and continuous control of intracranial hypertension avoiding the use of third tier therapies (therapeutic hypothermia, decompressive craniectomy, and barbiturate coma) or avoiding a decision to withdraw life sustaining treatment due to both refractory intracranial hypertension and severity of brain injury lesions.

RESULTS

83 patients with EVD were included. EVD was successful in 33 patients (40%). Thirty-two patients (39%) required a decompressive craniectomy, eight patients (9%) received barbiturate coma. In ten cases (12%) refractory intracranial hypertension prompted a protocolized withdrawal of care. Complications occurred in nine patients (11%) (three cases of ventriculitis, six cases of catheter occlusion). Multivariate analysis identified no independent factors associated with EVD success.

CONCLUSION

In a protocol-based management for traumatic brain injury, EVD allowed intracranial pressure control and avoided third tier therapeutic measures in 40% of cases with a favorable risk-benefit ratio.

Delayed recovery from severe refractory intracranial hypertension due to expansion of skin and pericranium stretch after decompressive craniectomy

PURPOSE

Decompressive craniectomy immediately reduces intracranial pressure by increasing space to accommodate brain volumes. Any delay in reduction of pressure and signs of severe intracranial hypertension requires explanation.

CLINICAL FEATURES

We present the case of a 13-yr-old boy presenting with a ruptured arteriovenous malformation resulting in a massive occipito-parietal hematoma and increased intracranial pressure (ICP) refractory to medical management. This patient ultimately underwent a decompressive craniectomy (DC) for alleviation of increased ICP, despite which the patient's hemorrhage continued to worsen to the point of brainstem areflexia suggestive of possible progression to brain death. Within hours of the decompressive craniectomy, the patient displayed a relatively sudden, marked improvement in clinical status, most notably a return in pupillary reactivity and significant decrease in measured ICP. A review of postoperative images after the decompressive craniectomy suggested increases in brain volume that continued beyond the initial postoperative period.

CONCLUSION

We urge caution to be taken in the interpretation of the neurologic examination and measured ICP in the context of a decompressive craniectomy. In the patient described in this Case Report, we propose that ongoing expansion of brain volume following a decompressive craniectomy beyond the initial postoperative period, possibly secondary to the stretch of skin or pericranium (used as a dural substitute for expansile duraplasty), can explain further clinical improvements beyond the initial postoperative period. We call for routine serial analyses of brain volumes after decompressive craniectomy to confirm these findings.