Lumbar drain trial outcomes of normal pressure hydrocephalus: a single-center experience of 254 patients

Prediction of Surgical Outcomes in Normal Pressure Hydrocephalus by MR Elastography

BACKGROUND AND PURPOSE

Normal pressure hydrocephalus is a treatable cause of dementia associated with distinct mechanical property signatures in the brain as measured by MR elastography. In this study, we tested the hypothesis that specific anatomic features of normal pressure hydrocephalus are associated with unique mechanical property alterations. Then, we tested the hypothesis that summary measures of these mechanical signatures can be used to predict clinical outcomes.

MATERIALS AND METHODS

MR elastography and structural imaging were performed in 128 patients with suspected normal pressure hydrocephalus and 44 control participants. Patients were categorized into 4 subgroups based on their anatomic features. Surgery outcome was acquired for 68 patients. Voxelwise modeling was performed to detect regions with significantly different mechanical properties between each group. Mechanical signatures were summarized using pattern analysis and were used as features to train classification models and predict shunt outcomes for 2 sets of feature spaces: a limited 2D feature space that included the most common features found in normal pressure hydrocephalus and an expanded 20-dimensional (20D) feature space that included features from all 4 morphologic subgroups.

RESULTS

Both the 2D and 20D classifiers performed significantly better than chance for predicting clinical outcomes with estimated areas under the receiver operating characteristic curve of 0.66 and 0.77, respectively (P < .05, permutation test). The 20D classifier significantly improved the diagnostic OR and positive predictive value compared with the 2D classifier (P < .05, permutation test).

CONCLUSIONS

MR elastography provides further insight into mechanical alterations in the normal pressure hydrocephalus brain and is a promising, noninvasive method for predicting surgical outcomes in patients with normal pressure hydrocephalus.

Improving Quality Care and Patient Safety With Implementation of an Oversew Stitch in Lumbar Drains

ABSTRACT

The lumbar drain exit site purse string oversew stitch is a well-described bedside intervention to stop or prevent cerebrospinal fluid (CSF) leak. It is not routinely placed at the time of lumbar drain placement. Via four plan-do-study-act (PDSA) cycles, we test the effect of prophylactic utilization of the lumbar drain exit site oversew stitch on house officers' paging burden, need to redress the drain, need to oversew the drain to stop a CSF leak, and need to replace the drain. We found that the simple act of placing an oversew stitch at the time of lumbar drain placement significantly reduced paging burden and reduced the frequency at which an oversew stitch was required to stop a CSF leak. Subjectively, during PDSA cycles during which overstitches were placed prophylactically, in-house residents perceived that there were less lumbar drains on service, although objectively, the overall number was unchanged. We conclude that prophylactic lumbar drain exit site stitch placement reduces risk and bedside interventions for patients and also reduces overall call burden on house officers. This simple intervention may therefore provide a more widespread improvement in care quality beyond lumbar drain care because house officers experience less burnout during their call shifts.

Neurocognitive change over the course of a multiday external lumbar drain trial in patients with suspected normal pressure hydrocephalus

Objective: To characterize neurocognitive response to cerebrospinal fluid (CSF) diversion during a multiday external lumbar drainage (ELD) trial in patients with suspected normal pressure hydrocephalus (NPH). Methods: Inpatients (N = 70) undergoing an ELD trial as part of NPH evaluation participated. Cognition and balance were assessed using standardized measures before and after a three-day ELD trial. Cognitive change pre- to post-ELD trial was assessed in relation to change in balance, baseline neuroimaging findings, NPH symptoms, demographics, and other disease-relevant clinical parameters. Results: Multiday ELD resulted in significant cognitive improvement (particularly on measures of memory and language). This improvement was independent of demographics, test-retest interval, number of medical and psychiatric comorbidities, NPH symptom duration, estimated premorbid intelligence, baseline level of cognitive impairment, cerebrovascular disease burden, degree of ventriculomegaly, or other NPH-related morphological brain alterations. Balance scores evidenced a greater magnitude of improvement than cognitive scores and were weakly, but positively correlated with cognitive change scores. Conclusions: Findings suggest that cognitive improvement associated with a multiday ELD trial can be sufficiently captured with bedside neurocognitive testing. These findings support the utility of neuropsychological consultation, along with balance assessment, in informing clinical decision-making regarding responsiveness to temporary CSF diversion for patients undergoing elective NPH evaluation. Implications for the understanding of neuroanatomical and cognitive underpinnings of NPH are discussed.

Cerebrospinal fluid flushing as a means of neuroprotection

Central nervous system (CNS) injury or disease states are often difficult to treat due to the closed system of the dura mater/blood-brain barrier and the bony skull and vertebrae. The closed system results in at least partial containment of any pro-inflammatory molecules, pathogens, or toxic byproducts in the case of brain or spinal cord lesions, which can result in a destructive feedback loop. Cervical-approach access techniques (lateral C1-C2, suboccipital and lateral atlanto-occipital space punctures) are less-common methods of cerebrospinal fluid (CSF) sampling due to the relative ease and safety of lumbar spinal taps. However, with improved image-guidance, these cervical-level CSF access points are still useful when there are certain contraindications and difficulties when attempting to sample the CSF via the typical lumbar spinal approach. With the advent of microcatheters and minimally invasive techniques, combined with body fluid filtration technology, the question arises: could dual microcatheters be introduced for inflow and outflow of purified or artificial CSF to break the destructive feedback loop and thus diminish CNS damage?. We hypothesize that intrathecal spinal catheters could be placed in 2 positions (e.g., via a cervical route and the typical lumbar spinal route) to allow for both an input and output to more effectively filter or "flush" the CSF. This could have broad implications in the treatment of strokes, traumatic brain or spinal cord injury, infections, autoimmune diseases, and even malignancies within the CNS-in short, any disease with abnormalities detectable in the CSF.

External Lumbar Drainage for Refractory Intracranial Hypertension in Traumatic Brain Injury: A Systematic Review

Considerable variation exists in the clinical practice of cerebrospinal fluid diversion for medically refractory intracranial hypertension in patients with acute traumatic brain injury (TBI), which is achievable via lumbar or ventricular drainage. This systematic review sought to compile the available evidence for the efficacy and safety of the use of lumbar drains for intracranial pressure (ICP) control.

A systematic review of the literature was performed with the search and data extraction performed by two reviewers independently in duplicate. Nine independent studies were identified, enrolling 230 patients, 159 with TBI. Efficacy for ICP control was observed across all studies, with immediate and sustained effect, reducing medical therapy requirements. Lumbar drainage with medical therapy appears effective when used alone and as an adjunct to ventricular drainage. Safety reporting varied in quality. Clinical or radiological incidents of cerebral herniation (with an unclear relationship to lumbar drainage) were observed in 14/230 patients resulting in one incident of morbidity without adverse patient outcome.

The available data is generally poor in quality and volume, but supportive of the efficacy of lumbar drainage for ICP control. Few reports of adverse outcomes are suggestive of, but are insufficient to confirm, the safety of use in the appropriate patient and clinical setting. Further large prospective observational studies are required to generate sufficient support of an acceptable safety profile.

Ultrasonography for Serial Monitoring and Management of Cerebrospinal Fluid Dynamic Disorders After Decompressive Craniectomy

Decompressive craniectomy (DC) is widely used to treat intracranial hypertension following severe head injury. However, impairments of cerebrospinal fluid (CSF) hydrodynamics such as hydrocephalus and subdural effusion are common complications that occur after DC. Therefore, monitoring of intracranial pressure is a staple of neurocritical care post-DC. The aim of this study was to assess the usefulness of transcranial duplex sonography (TDS) for serial monitoring and management of CSF disorders after DC.

Cerebrospinal Fluid Diversion for Refractory Intracranial Hypertension: A United Kingdom and Ireland Survey on Practice Variation

Introduction

Diversion of cerebrospinal fluid (CSF) in a traumatic brain injury (TBI) is an established means for achieving control of intracranial pressure (ICP), aimed at improving intracranial homeostasis. The literature and anecdotal reports suggest a variation in practice between neurosurgical centres internationally, with current guidelines advocating ventricular drainage over lumbar drainage. We sought to establish the current neurosurgical practice in the United Kingdom regarding the methods of ICP control in TBI.

Methods

A 20-point survey was distributed electronically to British and Irish neurosurgeons after ratification by the Society of British Neurological Surgeons. Questions were directed at the clinician’s opinion and experience of lumbar drain usage in patients with TBI: frequency, rationale, and experience of complications. Questions on lumbar drain usage in neurovascular patients were asked for practice comparison.

Results

Thirty-six responses from 21 neurosurgical centres were returned. Twenty-three per cent (23%) of responders reported using lumbar drains for refractory ICP in TBI patients: six units use lumbar drains and 15 do not. Three units showed partial usage, with mixed “yes/no” responses between consultants. Concerns of tonsillar herniation and familiarity with EVD were commonly given reasons against the usage of lumbar drains. Fifty-six per cent (56%) reported use in neurovascular patients.

Conclusion

This contemporary practice survey demonstrates mixed practice across the UK and within some centres. Responses and survey feedback demonstrate that the use of lumbar drains in TBI is a polarising topic. The variety of practice between and within neurosurgical units supports consideration of the prospective study of CSF diversion methods for control of refractory ICP in patients with TBI.

Case Series of Rapid Surgical Interventions in Fulminant Intracranial Hypertension

AIMS

Examine ophthalmologic outcomes and complications of lumbar drain and cerebrospinal fluid shunts in pediatric fulminant intracranial hypertension.

METHODS

Patients under 21 years of age with a diagnosis of fulminant intracranial hypertension with temporary lumbar drain only, shunt after lumbar drain, and shunt only were included. Parameters investigated include lumbar drain data, medication freedom, time to resolution of papilledema, improvement in cranial nerve palsy, afferent pupillary defects, visual fields, visual acuity, and complications of each intervention.

RESULTS

Four patients had temporary lumbar drain, 2 temporary lumbar drain and cerebrospinal fluid shunt, and 3 shunt only. All achieved medication freedom and resolution of papilledema and cranial nerve palsies (if present). Most had resolution of preprocedure afferent pupillary defects. Minor residual visual field deficits occurred in 67%, and all had visual acuity improvement. One patient's lumbar drain dislodged, and one patient had 2 cerebrospinal fluid shunt revisions.

CONCLUSION

Temporary lumbar drain with medical therapy may be a viable first approach to fulminant intracranial hypertension.

Minimally invasive intrathecal spinal cord imaging with optical coherence tomography

SIGNIFICANCE

Imaging of the spinal cord is challenging due to the surrounding bony anatomy, physiologic motion, and the small diameter of the spinal cord. This precludes the use of non-invasive imaging techniques in assessing structural changes related to trauma and evaluating residual function.

AIM

The purpose of our research was to apply endovascular technology and techniques and construct a preclinical animal model of intrathecal spinal cord imaging using optical coherence tomography (OCT).

APPROACH

Five animals (2 Yorkshire Swine and 3 New Zealand Rabbits) were utilized. Intrathecal access was gained using a 16-guage Tuohy, and an OCT catheter was advanced under roadmap technique into the cervical canal. The OCT catheter has a motorized pullback, and a total length of 54 mm of the spinal canal is imaged.

RESULTS

Image acquisition was successful for all animals. There were no instances of difficult catheter navigation, enabling OCT imaging rostrally to C2. The thecal sac provided excellent thoroughfare for the OCT catheter. The clear cerebrospinal fluid also provided an excellent medium for image acquisition, with no detectable artifact from the contents of the cerebrospinal fluid. The anatomical space of the spinal canal could be readily appreciated including: dural lining of the thecal sac, epidural veins, pial lining of the spinal cord, arachnoid bands, dentate ligaments, and nerve rootlets/roots.

CONCLUSION

Minimally invasive intrathecal imaging using endovascular OCT was feasible in this preclinical animal study. The repurposing of an endovascular device for spinal imaging comes with limitations, and a spine-specific device is necessary.

iNPH with parkinsonism: response to lumbar CSF drainage and ventriculoperitoneal shunting

OBJECTIVES

To evaluate clinical response after external lumbar drainage (ELD) and ventriculoperitoneal shunting (VPS) in a cohort of patients with idiopathic normal pressure hydrocephalus associated with parkinsonism (iNPH-P), considering parkinsonism as clinical primary outcome.

METHODS

Patients underwent long-term 72-h intracranial pressure-controlled CSF ELD. Clinical motor response before and after ELD was evaluated using changes in UPDRS-ME as outcome measure. A standardized cognitive assessment was also performed. iNPH-P patients who underwent VPS were clinically followed-up after surgery.

RESULTS

Fourteen iNPH-P patients (age: 69.3 ± 11.6 years) were studied. The time of evaluation after ELD removal was 3.5 ± 1.8 days. We observed a significant motor improvement after the drainage in eight (57.1%) patients. Percent clinical motor response was 18.4 ± 6.7%. Twelve (85.7%) patients underwent VPS. Nine patients were examined after surgery at 31.6 ± 7 months. Four (44.4%) patients presented a clinically detectable improvement in motor response after VPS. No significant changes in cognitive performances were detected.

CONCLUSIONS

A clinically detectable motor response on parkinsonian signs was observed in a consistent part of iNPH-P patients few days after ELD as well as over two and half years after VPS. Parkinsonism should be considered as outcome measure for the clinical management of patients with iNPH-P.

Secondary deterioration in patients with normal pressure hydrocephalus after ventriculoperitoneal shunt placement: a proposed algorithm of treatment

Background

After ventriculoperitoneal shunt surgery for idiopathic normal pressure hydrocephalus (iNPH) with adjustable gravitational valves, a certain proportion of patients develop secondary clinical worsening after initial improvement of clinical symptoms. The aim of this study was to analyze this group of patients with secondary deterioration and to evaluate the performed shunt management.

Methods

For this investigation, we retrospectively reviewed our NPH registry for patients included between 1999 and 2013 with a decrease by a minimum of two points in the Kiefer score in the first year of follow up and an increase of two points in the Kiefer score between the second and the fifth year after shunt surgery (secondary deterioration). Then, we analyzed the patient’s shunt management (adapting the valve pressure setting, shuntography, valve replacement, catheter replacement, implant an adjustable gravitational unit). Additionally, we searched for risk factors for secondary deterioration.

Results

Out of 259 iNPH patients, 53 (20%) patients showed secondary deterioration on an average of 2.7 (2–4 years) years after shunt surgery. Fourteen (26%) patients with secondary deterioration improved after shunt or valve management and 58% remained without clinical benefit after management. We had a drop-out rate of 15% due to incomplete datasets. Our shunt management reduced the rate of secondary deterioration from 20 to 15%. On the basis of our findings, we developed an algorithm for shunt management. Risk factors for secondary deterioration are the age of the patient at the time of shunting, newly diagnosed neurodegenerative diseases, and overdrainage requiring adjusting the valve to higher-pressure levels.

Conclusion

Twenty percent of patients with iNPH were at risk for secondary clinical worsening about 3 years after shunt surgery. About one-fourth of these patients benefited for additional years from pressure level management and/or shunt valve revision. Our findings underline the need for long-term follow-ups and intensive shunt management to achieve a favorable long-term outcome for patients with iNPH and VPS.

Schizophrenia-related microdeletion causes defective ciliary motility and brain ventricle enlargement via microRNA-dependent mechanisms in mice

Progressive ventricular enlargement, a key feature of several neurologic and psychiatric diseases, is mediated by unknown mechanisms. Here, using murine models of 22q11-deletion syndrome (22q11DS), which is associated with schizophrenia in humans, we found progressive enlargement of lateral and third ventricles and deceleration of ciliary beating on ependymal cells lining the ventricular walls. The cilia-beating deficit observed in brain slices and in vivo is caused by elevated levels of dopamine receptors (Drd1), which are expressed in motile cilia. Haploinsufficiency of the microRNA-processing gene Dgcr8 results in Drd1 elevation, which is brought about by a reduction in Drd1-targeting microRNAs miR-382-3p and miR-674-3p. Replenishing either microRNA in 22q11DS mice normalizes ciliary beating and ventricular size. Knocking down the microRNAs or deleting their seed sites on Drd1 mimicked the cilia-beating and ventricular deficits. These results suggest that the Dgcr8-miR-382-3p/miR-674-3p-Drd1 mechanism contributes to deceleration of ciliary motility and age-dependent ventricular enlargement in 22q11DS.

Structural volumetry in NPH diagnostics and treatment-future or dead end?

To assess automated volumetric analysis as a potential presurgical diagnostic tool or as a method to potentially shed light on normal pressure hydrocephalus (NPH) pathophysiology. MRI imaging according to our protocol was performed in 29 NPH patients, 45 non-NPH (but suspected) patients and 15 controls. Twenty patients underwent a second MRI 3 months after ventriculoperitoneal (VP) shunt surgery. All structures relevant to NPH diagnosis were automatically segmented using commercial software. The results were subsequently tested using ANOVA analysis. Significant differences in the volumes of the corpus callosum, left hippocampus, internal globus pallidus, grey and white matter and ventricular volumes were observed between NPH group and healthy controls. However, the differences between NPH and non-NPH groups were non-significant. Three months after, VP shunt insertion decreased ventricular volume was the only clearly significant result (p value 0.0001). Even though a detailed volumetric study shows several significant differences, volumetric analysis as a standalone method does not provide a simple diagnostic biomarker, nor does it shed a light on an unknown NPH aetiology.