Impaired pulsation absorber mechanism in idiopathic normal pressure hydrocephalus

Park, Eun-Hyoung; Eide, Per Kristian; Zurakowski, David; Madsen, Joseph R.

doi:10.3171/2012.9.jns121227

Cited by 22 publications

(12 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The physiological role of the astrocytic endfeet is debated, but it may be proposed that the volume regulation of the endfeet may act as a pulsation absorber for the arterial blood pressure pulsations created by cardiac contractions. In previous studies, we proposed the existence of a cardiac pulsation absorbance from a biophysical and pressure signaling perspective [28], but without an underlying biological perspective.…”

Section: Discussionmentioning

confidence: 99%

Abnormal Intracranial Pulse Pressure Amplitude Despite Normalized Static Intracranial Pressure in Idiopathic Intracranial Hypertension Refractory to Conservative Medical Therapy

Eide

2021

Life

Self Cite

View full text Add to dashboard Cite

Idiopathic intracranial hypertension (IIH) incorporates symptoms and signs of increased intracranial pressure (ICP) and is diagnosed by increased lumbar cerebrospinal fluid pressure. However, our knowledge about the characteristics of ICP abnormality, e.g., changes in pulsatile versus static ICP, remains scarce. This study questioned how overnight pulsatile ICP (mean ICP wave amplitude, MWA) associates with static ICP (mean ICP) in IIH patients who were refractory to conservative medical treatment. The material included 80 consecutive IIH patients undergoing ICP monitoring prior to shunt, as part of work-up for failed conservative medical therapy. In this group, the overnight mean ICP was normalized in 52/80 patients, but with abnormal overnight MWA in 45 of the 52 patients. Even though there was a positive correlation between MWA and mean ICP at group level and within individual ICP recordings, the levels of MWA were abnormal in a high proportion of patients despite normalized mean ICP. Taken together, the present results disclosed lasting abnormal pulsatile ICP despite normalized static ICP in IIH patients refractory to conservative medical therapy, which may reflect the underlying pathophysiology. It is tentatively suggested that abnormal pulsatile ICP in IIH may reflect alterations at the glia–neurovascular interface, resulting in impaired astrocytic pulsation absorber mechanisms.

show abstract

Section: Discussionmentioning

confidence: 99%

Abnormal Intracranial Pulse Pressure Amplitude Despite Normalized Static Intracranial Pressure in Idiopathic Intracranial Hypertension Refractory to Conservative Medical Therapy

Eide

2021

Life

Self Cite

View full text Add to dashboard Cite

show abstract

“…Previous canine studies have demonstrated that brain compliance is dynamic and displays a frequency‐dependent function with enhanced pulsatility absorbance around cardiac frequency . This phenomenon is diminished in canine models of hydrocephalus as well as in INPH patients . In keeping with these experimental findings, Eide and Sorteberg demonstrated that 93% of patients with increased ICP pulsatility improved after shunt surgery compared with only 10% of patients without increased ICP pulsatility.…”

Section: Pathophysiologymentioning

confidence: 66%

“…Animal and hydrodynamic human studies have implicated elevations of CSF pressure as a core defect in INPH . The increased frequency of episodic pressure elevations, called B‐waves, observed on continuous intracranial pressure (ICP) monitoring is consistent with this . It is generally accepted that this increased ICP pulse amplitude suggests a decrease in brain compliance, which may play a central role in INPH pathophysiology .…”

Section: Pathophysiologymentioning

confidence: 79%

A Review of Clinical Outcomes for Gait and Other Variables in the Surgical Treatment of Idiopathic Normal Pressure Hydrocephalus

Shaw

Mahant

Jacobson

et al. 2016

Movement Disord Clin Pract

View full text Add to dashboard Cite

Background: Idiopathic normal pressure hydrocephalus (INPH) is a treatable cause of gait disturbance, cognitive impairment, and urinary incontinence. This clinical triad of symptoms occurs in association with ventriculomegaly and normal cerebrospinal fluid (CSF) pressure. Although the treatment outcomes after CSF shunting for INPH have improved significantly since its first description in 1965, shortcomings in our understanding still remain. Not all INPH patients exhibit clinical improvement after shunting, and it is challenging to identify patients who are more likely to benefit from shunting. Methods: The Cochrane Library, Medline, Embase, and PubMed databases were searched for Englishlanguage publications between 1965 and October 2015. Reference lists of publications were also manually searched for additional publications. Results: The findings of this review indicate that, despite efforts to improve patient selection, the degree of clinical improvement after shunting continues to demonstrate significant variability both within and between studies. These discrepancies in treatment outcomes are the result of controversies in 3 distinct but interrelated domains: the underlying pathophysiology of INPH, the diagnosis of INPH, and the identification of likely shunt-responders. Conclusions: This review focuses on these 3 areas and their relation to surgical treatment outcomes. Despite the limitations of published outcome studies and limitations in our understanding of INPH pathophysiology, shunting is a safe and effective means of achieving meaningful clinical improvement in most patients with INPH.Normal pressure hydrocephalus (NPH) was first reported in 1965 as a triad of dementia, gait disturbance, and urinary incontinence, with associated ventricular dilatation and normal cerebrospinal fluid (CSF) pressure.1 NPH can be classified as idiopathic NPH (INPH) or secondary NPH (SNPH), the latter of which occurs most commonly after subarachnoid hemorrhage, trauma, or meningitis. 2 Although CSF diversion via a shunt is the mainstay of NPH management, surgical outcomes in INPH have been consistently less successful than those in SNPH. [3][4][5] In addition, the reported rates of postoperative clinical improvement in INPH patients have varied from 24% to 96%. 6,7 These discrepancies in treatment outcomes are the result of controversies in 3 domains: the underlying pathophysiology of INPH, the diagnosis of INPH, and the identification of likely shunt-responders. This review focuses on these 3 areas of controversy and their relation to surgical outcomes. The Cochrane Library, Medline, Embase, and PubMed were searched for English-language publications between 1965 and October 2015 using a combination of medical subject headings and free text key words such as: "normal pressure hydrocephalus," "treatment," "outcome," and "cerebrospinal fluid shunt." Reference lists of publications

show abstract

“…20 Impaired intracranial compliance and elevated ICP wave amplitudes can also be associated with reduced function of intracranial absorber mechanisms. 36 Prior to shunting of hydrocephalus, the ICP wave amplitudes in patients are elevated, indicative of impaired intracranial compliance. 22 Moreover, shunting normalizes the ICP waves, and adjustment of opening pressure can tailor levels of ICP waves.…”

Section: Icp Scores and Type Of Shunt Failurementioning

confidence: 99%

Intracranial pressure monitoring in pediatric and adult patients with hydrocephalus and tentative shunt failure: a single-center experience over 10 years in 146 patients

Sæhle

Eide

2015

JNS

Self Cite

View full text Add to dashboard Cite

Shunt surgery is the primary treatment of pediatric and adult hydrocephalus, 42 although shunt failure requiring shunt revision is frequent. 2,8,12,45 Shunt failure may be accompanied by over-or underdrainage of CSF. When the shunt is draining too much CSF (overdrainage), symptoms such as headache and dizziness may arise. 9,37 However, symptoms such as headache and dizziness may also be caused by CSF underdrainage, e.g., due to obstruction of the CSF catheter. 10 The shunt valves with adjustable CSF opening pressure have been reported to reduce the occurrence of shunt failures. 48 However, in a recent randomized controlled dual-center trial, 39 we found the same rate of shunt complications and overdrainage symptoms in patients with hydrocephalus receiving a shunt with a fixed valve setting of 13 cm H 2 O, as compared with those in whom gradual lowering of the valve setting to a mean of 7 cm H 2 O was performed. These results highlight the need for a better understanding of how shunts influence in- obJect In patients with hydrocephalus and shunts, lasting symptoms such as headache and dizziness may be indicative of shunt failure, which may necessitate shunt revision. In cases of doubt, the authors monitor intracranial pressure (ICP) to determine the presence of over- or underdrainage of CSF to tailor management. In this study, the authors reviewed their experience of ICP monitoring in shunt failure. The aims of the study were to identify the complications and impact of ICP monitoring, as well as to determine the mean ICP and characteristics of the cardiac-induced ICP waves in pediatric versus adult over- and underdrainage. methods The study population included all pediatric and adult patients with hydrocephalus and shunts undergoing diagnostic ICP monitoring for tentative shunt failure during the 10-year period from 2002 to 2011. The patients were allocated into 3 groups depending on how they were managed following ICP monitoring: no drainage failure, overdrainage, or underdrainage. While patients with no drainage failure were managed conservatively without further actions, over- or underdrainage cases were managed with shunt revision or shunt valve adjustment. The ICP and ICP wave scores were determined from the continuous ICP waveforms.results The study population included 71 pediatric and 75 adult patients. There were no major complications related to ICP monitoring, but 1 patient was treated for a postoperative superficial wound infection and another experienced a minor bleed at the tip of the ICP sensor. Following ICP monitoring, shunt revision was performed in 74 (51%) of 146 patients, while valve adjustment was conducted in 17 (12%) and conservative measures without any actions in 55 (38%).Overdrainage was characterized by a higher percentage of episodes with negative mean ICP less than −5 to −10 mm Hg. The ICP wave scores, in particular the mean ICP wave amplitude (MWA), best differentiated underdrainage. Neither mean ICP nor MWA levels showed any significant association with age. coNclusioNs In this coho...

show abstract

Impaired pulsation absorber mechanism in idiopathic normal pressure hydrocephalus

Cited by 22 publications

References 29 publications

Abnormal Intracranial Pulse Pressure Amplitude Despite Normalized Static Intracranial Pressure in Idiopathic Intracranial Hypertension Refractory to Conservative Medical Therapy

Abnormal Intracranial Pulse Pressure Amplitude Despite Normalized Static Intracranial Pressure in Idiopathic Intracranial Hypertension Refractory to Conservative Medical Therapy

A Review of Clinical Outcomes for Gait and Other Variables in the Surgical Treatment of Idiopathic Normal Pressure Hydrocephalus

Intracranial pressure monitoring in pediatric and adult patients with hydrocephalus and tentative shunt failure: a single-center experience over 10 years in 146 patients

Contact Info

Product

Resources

About