The role of ICP monitoring in patients with persistent cerebrospinal fluid leak following spinal surgery: a case series

Ambulatory intracranial pressure in humans: ICP increases during movement between body positions

Introduction

Positional changes in intracranial pressure (ICP) have been described in humans when measured over minutes or hours in a static posture, with ICP higher when lying supine than when sitting or standing upright. However, humans are often ambulant with frequent changes in position self-generated by active movement.

Research question

We explored how ICP changes during movement between body positions.

Material and methods

Sixty-two patients undergoing clinical ICP monitoring were recruited. Patients were relatively well, ambulatory and of mixed age, body habitus and pathology. We instructed patients to move back and forth between sitting and standing or lying and sitting positions at 20 s intervals after an initial 60s at rest. We simultaneously measured body position kinematics from inertial measurement units and ICP from an intraparenchymal probe at 100 Hz.

Results

ICP increased transiently during movements beyond the level expected by body position alone. The amplitude of the increase varied between participants but was on average ∼5 mmHg during sit-to-stand, stand-to-sit and sit-to-lie movements and 10.8 mmHg [95%CI: 9.3,12.4] during lie-to-sit movements. The amplitude increased slightly with age, was greater in males, and increased with median 24-h ICP. For lie-to-sit and sit-to-lie movements, higher BMI was associated with greater mid-movement increase (β = 0.99 [0.78,1.20]; β = 0.49 [0.34,0.64], respectively).

Discussion and conclusion

ICP increases during movement between body positions. The amplitude of the increase in ICP varies with type of movement, age, sex, and BMI. This could be a marker of disturbed ICP dynamics and may be particularly relevant for patients with CSF-diverting shunts in situ.

Patient-specific automated cerebrospinal fluid pressure control to augment spinal wound closure: a case series using the LiquoGuard®

OBJECTIVE

Spinal cerebrospinal fluid (CSF) leaks are common, and their management is heterogeneous. For high-flow leaks, numerous studies advocate for primary dural repair and CSF diversion. The LiquoGuard7® allows automated and precise pressure and volume control, and calculation of patient-specific CSF production rate (prCSF), which is hypothesized to be increased in the context of durotomies and CSF leaks.

METHODS

This single-centre illustrative case series included patients undergoing complex spinal surgery where: 1) a high flow intra-operative and/or post-operative CSF leak was expected and 2) lumbar CSF drainage was performed using a LiquoGuard7®. CSF diversion was tailored to prCSF for each patient, combined with layered spinal wound closure.

RESULTS

Three patients were included, with a variety of pathologies: T7/T8 disc prolapse, T8-T9 meningioma, and T4-T5 metastatic spinal cord compression. The first two patients underwent CSF diversion to prevent post-op CSF leak, whilst the third required this in response to post-op CSF leak. CSF hyperproduction was evident in all cases (mean >/=140ml/hr). With patient-specific CSF diversion regimes, no cases required further intervention for CSF fistulae repair (including for pleural CSF effusion), wound breakdown or infection.

CONCLUSIONS

Patient-specific cerebrospinal fluid drainage may be a useful tool in the management of high-flow intra-operative and post-operative CSF leaks during complex spinal surgery. These systems may reduce post-operative CSF leakage from the wound or into adjacent body cavities. Further larger studies are needed to evaluate the comparative benefits and cost-effectiveness of this approach.

Impact of delay extubation on the reintubation rate in patients after cervical spine surgery: a retrospective cohort study

BACKGROUND

The incidence of cervical airway obstruction after cervical spine surgery (CSS) ranges from 1.2 to 14%, and some require reintubation. If not addressed promptly, the consequences can be fatal. This study investigated delayed extubation's effect on patients' reintubation rate after cervical spine surgery.

METHODS

We performed a retrospective case-control analysis of cervical spine surgery from our ICU from January 2021 to October 2022. Demographic and preoperative characteristics, intraoperative data, and postoperative clinical outcomes were collected for all 94 patients. Univariable analysis and multivariable logistic regression were used to analyze postoperative unsuccessful extubation risk factors following cervical spine surgery.

RESULTS

The patients in the early extubation (n = 73) and delayed extubation (n = 21) groups had similar demographic characteristics. No significant differences were found in the reintubation rate (0 vs. 6.8%, p = 0.584). However, the delayed extubation group had significantly more patients with 4 and more cervical fusion segments (42.9 vs. 15.1%, p = 0.013),more patients with an operative time greater than 4 h (33.3 vs. 6.8%, p = 0.004)and all patients involved C2-4 (78 vs. 100%, p = 0.019).Also, patients in the delayed extubation group had a longer duration of ICU stay (152.9 ± 197.1 h vs. 27.2 ± 45.4 h, p < 0.001) and longer duration of hospital stay (15.2 ± 6.9 days vs. 11.6 ± 4.1 days, p = 0.003). Univariate and multivariate analysis identified the presences of cervical spondylotic myelopathy (CSM) (OR 0.02, 95% CI 0-0.39, p = 0.009) and respiratory diseases (OR: 23.2, 95% CI 2.35-229.51, p = 0.007) as unfavorable prognostic factor for reintubation.

CONCLUSIONS

Our analysis of patients with cervical spondylosis who received CSS indicated that delayed extubation was associated with the presence of respiratory diseases and CSM, longer operative time, more cervical fusion segments, and longer duration of ICU and hospital stays.

Spontaneous intracranial hypotension complicated by diffuse cerebral edema and episodes of severely elevated intracranial pressure: illustrative case

BACKGROUND

Spontaneous intracranial hypotension (SIH) is a well-documented condition that typically follows a defined clinical course. Previously published studies describing the pathophysiology of SIH have demonstrated extensive evidence of low intracranial pressure (ICP) driving the clinical features of the condition. Through lumbar puncture and use of intracranial monitoring devices, however, both low and normal cerebrospinal fluid (CSF) pressures have been documented. This report outlined and discussed the unique finding of elevated ICP associated with clinical features of SIH.

OBSERVATIONS

Here, the authors presented a case of a patient with spontaneous spinal CSF leak who developed tonsillar herniation, cerebral edema, and subsequent episodes of elevated ICP. Although more diverse presentations of SIH are being reported, the authors believed the case to be unique because SIH was accompanied by elevated ICP.

LESSONS

This case adds to the growing body of literature surrounding SIH by demonstrating that patients can develop elevated CSF pressures associated with acute encephalopathy.

Spontaneous Spinal Cerebrospinal Fluid Leak: Review and Management Algorithm

Spontaneous spinal cerebrospinal fluid (CSF) leak is a condition that commonly presents with debilitating positional headaches. Often, the cause of the leak is located in the spine. Although often cured with conservative management, including epidural blood patching, a subset of patients are refractory to this initial management. Determining the focal location of the spinal leak can, in some patients, require several imaging modalities. Treatment similarly involves multiple options, including targeted epidural blood and/or fibrin patching as well as surgical closure. In this article, we review the current literature regarding this challenging condition and present an algorithm for management.

Extracranial versus intracranial hydro-hemodynamics during aging: a PC-MRI pilot cross-sectional study

Background

Both aging and changes in blood flow velocity between the extracranial (intraspinal) and intracranial regions of cerebral vessels have an impact on brain hydro-hemodynamics. Arterial and venous cerebral blood flows interact with cerebrospinal fluid (CSF) in the both the cranial and spinal systems. Studies suggest that increased blood and CSF flow pulsatility plays an important role in certain neurological diseases. Here, we investigated the changes in blood-CSF flow pulsatility in the cranial and spinal systems with age as well as the impact of the intracranial compartment on flow patterns.

Method

Phase-contrast magnetic resonance imaging (PC-MRI) was performed in 16 young and 19 elderly healthy volunteers to measure the flows of CSF and blood. CSF stroke volume (SV), blood SV, and arterial and venous pulsatility indexes (PIs) were assessed at intra- and extracranial levels in both samples. Correlations between ventricular and spinal CSF flow, and between blood and CSF flow during aging were also assessed.

Results

There was a significant decrease in arterial cerebral blood flow and intracranial venous cerebral blood flow with aging. We also found a significant increase of intracranial blood SV, spinal CSF SV and arterial/venous pulsatility indexes with aging. In regard to intracranial compartment impact, arterial and venous PIs decreased significantly at intracranial level in elderly volunteers, while young adults exhibited decrease in venous PI only. Intracranial venous PI was paradoxically lower than extracranial venous PI, regardless of age. In both sample groups, spinal CSF SV and aqueductal CSF SV were positively correlated, and so were extracranial blood and spinal CSF SVs.

Conclusion

The study demonstrates that aging changes blood flow but preserves blood and CSF interactions. We also showed that many parameters related to blood and CSF flows differ between young and elderly adults.

Extradural Compressive Spinal Cerebrospinal Fluid Leak in Ehlers-Danlos Syndrome

Ehlers-Danlos syndrome can be associated with cerebrospinal fluid (CSF) disturbances including recurrent CSF leak and Chiari I malformations. Persistent pseudomeningoceles are known to be associated with raised intracranial pressure. We present an unusual case of a compressive epidural CSF collection occurring after a computed tomography-guided L5 nerve root block and describe an effective management strategy.

An odd and serious "disc bulging"!

BACKGROUND AND IMPORTANCE

Cauda equina syndrome is a common acute medical condition, usually caused by large degenerative disc herniation or metastatic lumbar disease. We describe a patient who presented with a lesion featuring both discal and tumoral characteristics.

CLINICAL PRESENTATION

A 41-year-old woman presented with ongoing back pain, progressive lower-limb weakness and sphincter disorder. Magnetic resonance imaging showed a very odd-looking large anterior epidural lesion originating from the L3-L4 space and severely compressing the roots of the cauda equina. Partial surgical decompression was performed in emergency. At a later time, redo surgery was performed to maximize resection, and was unfortunately followed by several complications. After 6 surgical procedures including a ventriculo-peritoneal shunt insertion and intensive rehabilitation, the patient could walk independently with the aid of one crutch. Following collegial review, the diagnosis of low-grade chondrosarcoma of the intervertebral disc was suggested.

CONCLUSION

We report on a very unusual and therapeutically challenging spinal tumor diagnosed as low-grade chondrosarcoma of discal origin, an entity never previously described.

Clinical and Magnetic Resonance Imaging Characteristics of Postfenestration Optic Nerve Sheath Pseudomeningoceles

PURPOSE

The clinical significance of postoperative pseudomeningocele formation following optic nerve sheath fenestration (ONSF) has not been fully characterized. A literature review identifies 9 previously published cases the authors believe demonstrate pseudomeningocele formation and approximately 19 other similar findings that were either transient or less defined blebs. This study was undertaken to more clearly define the clinical, radiographic, and histopathologic features associated with this entity.

METHODS

Sixteen-year, single-center, retrospective chart review of all ONSF cases performed by 2 surgeons. Clinical data, intracranial pressure, radiographic imaging, and histopathology of clinically detected pseudomeningoceles after ONSF were reviewed.

RESULTS

Eighty-six eyes in 57 patients underwent ONSF (28 unilateral, 12 bilateral sequential, 17 bilateral simultaneous). Forty-nine of 57 patients had elevated intracranial pressure preoperatively (41 idiopathic intracranial hypertension, 4 venous thrombosis, 2 meningitis, 1 arteriovenous malformation, and 1 sarcoid). In 32 patients undergoing postoperative imaging, 4 eyes (4.7%) in 4 patients developed well-defined pseudomeningoceles, of which 3 were symptomatic and 2 required surgical revision. Each pseudomeningocele developed in the setting of elevated preoperative intracranial pressure (350, 360, 430, 500 mm H20). Magnetic resonance imaging and/or computed tomography revealed sharply demarcated fluid-filled sacs adjacent to the optic nerve. The contents of these sacs were hypointense on T1-weighted imaging, hyperintense on T2-weighting, variably enhanced with contrast, and hypointense on fluid attenuated inversion recovery, and were thus consistent with cerebrospinal fluid. Histopathologic analysis of one of these outpouchings demonstrated an acellular, fibrocollagenized lining consistent with pseudomeningocele. Three eyes in 3 additional patients had less well-defined findings on imaging interpreted as bleb-like or cyst-like change.

CONCLUSIONS

Pseudomeningoceles following ONSF may be asymptomatic or may cause symptomatic orbital mass effect and rarely visual loss, amendable to surgical excision. Post-ONSF pseudomeningoceles are identified on computed tomography or magnetic resonance imaging to occur at the locations of fenestration sites and contain cerebrospinal fluid communicating with the subdural space that may act as a "filtration" bleb in some cases. Imaging findings may represent a spectrum spanning intraorbital cerebrospinal fluid leakage, partial walling off of bleb, or fully developed cysts. Resection of optic nerve pseudomeningoceles is considered in symptomatic cysts or eyes with papilledema that fails to improve.