Lumboperitoneal shunts for the treatment of normal pressure hydrocephalus

Effectiveness and safety of ventriculoperitoneal shunt versus lumboperitoneal shunt for communicating hydrocephalus: A systematic review and meta-analysis with trial sequential analysis

INTRODUCTION

The current standard surgical treatment for cerebrospinal fluid diversion is a ventriculoperitoneal shunt (VPS) implantation. Lumboperitoneal shunts (LPS) are an alternative treatment for communicating hydrocephalus. Prior studies comparing these two included a limited number of participants.

METHODS

We performed a meta-analysis determined the treatment failure, complications and effectiveness of lumboperitoneal shunt for communicating hydrocephalus. We reviewed studies with clinical and imaging diagnoses of communicating hydrocephalus, all causes and subtypes of communicating hydrocephalus, and studies that analyzed the primary and secondary outcomes listed below. We included randomized controlled trials (RCTs), non-RCTs and retrospective studies. We performed the meta-analysis in R, using a random-effects model and reporting 95% confidence intervals.

RESULTS

Data from 25 studies, including 3654 patients, were analyzed. The total complication rates were 12.98% (188/1448) for lumboperitoneal shunt and 23.80% (398/1672) for ventriculoperitoneal shunt. The odds ratio for lumboperitoneal shunt versus ventriculoperitoneal shunt complication rates was 0.29 (95% CI 0.19 to 0.45, p < 0.0001), and the I² was 72%. The shunt obstruction/malfunction rate was 3.99% (48/1204) for lumboperitoneal shunt and 8.31% (115/1384) for ventriculoperitoneal shunt (Odds ratio 0.54, 95% CI 0.37 to 0.79, p = 0.002, I²  = 0%). Based on the Modified Rankin Scale score, there were no differences in effectiveness between lumboperitoneal shunt and ventriculoperitoneal shunt. Nevertheless, lumboperitoneal shunt improved radiological outcomes.

CONCLUSIONS

This analysis demonstrated that lumboperitoneal shunt is a safe and equally effective choice for treating communicating hydrocephalus. More studies are needed to confirm the safety of lumboperitoneal shunt.

Lumboperitoneal Shunt Combined With Ommaya Reservoir Enables Continued Intraventricular Chemotherapy for Leptomeningeal Metastasis With Increased Intracranial Pressure

BACKGROUND

Intra-cerebrospinal fluid (CSF) chemotherapy for leptomeningeal metastasis (LM) can be delivered intraventricularly via an Ommaya reservoir. However, hydrocephalus associated with LM can interfere with chemotherapeutic drug distribution, and ventriculoperitoneal shunts can prevent drug distribution to the extra-ventricular CSF space. This study examined the feasibility of combining a lumboperitoneal (LP) shunt with an Ommaya reservoir to both control intracranial pressure and allow for intraventricular chemotherapy.

METHODS

We identified 16 patients with LM who received both an Ommaya reservoir and an LP shunt, either concurrently or sequentially, and subsequently received intraventricular chemotherapy. The feasibility of this combination for intraventricular chemotherapy was evaluated by assessing 1) the distribution of intraventricularly injected drugs in CSF samples collected 0, 6, and 12 h post-injection and 2) adverse events associated with the procedure and drug administration.

RESULTS

Patients received a median of seven rounds (range 1-37) of intraventricular chemotherapy during a median follow-up period of 5.2 months after LP shunt insertion. Pharmacokinetic data were obtained from six patients. Baseline methotrexate (MTX) levels from Ommaya reservoirs varied from 339.9 µM to 1,523.5 µM. CSF sampled from LP shunt reservoirs revealed an elimination half-life (t1/2) of 2.63 h, and the mean ratio of MTX concentration at 12 h to that at baseline was 0.05±0.05, ensuring drug distribution from the ventricle to the spinal canal. Nine patients (56%) underwent revision surgery due to catheter migration, malfunction, or infection. Among these patients, CSF infections attributable to intraventricular chemotherapy (n=3) occurred, but no infections occurred in later cases after we began to employ a complete aseptic technique.

CONCLUSION

LP shunt combined with Ommaya reservoir insertion is a feasible option for achieving both intracranial pressure control and the continuation of intraventricular chemotherapy in patients with LM.

Development of a Lumbar Extradural Arachnoid Cyst Associated with a Lumbar Catheter of Lumboperitoneal Shunt: A Case Report

A 78-year-old man, who had undergone lumboperitoneal shunt (LPS) placement for idiopathic normal-pressure hydrocephalus eight years prior, presented with intermittent claudication, lower back pain, and radicular pain on the inside of the right thigh. Magnetic resonance imaging (MRI) revealed an extradural arachnoid cyst (EDAC) above the lumbar catheter of the LPS. The EDAC compressed the spinal dural sac and cauda equina toward the anterior side at level L3/4, triggering his clinical manifestations. The LPS was removed and simultaneously converted into a ventriculoperitoneal shunt (VPS), which immediately improved the neurological deficits. Postoperative MRI showed shrinkage of the cyst and restoration of the compressed cauda equina. Spinal EDAC is a rare entity resulting from arachnoid membrane herniation due to a small defect in the dura mater. This is the first report showing that symptomatic EDAC can be accompanied by the lumbar catheter of the LPS and that a mere conversion from LPS to VPS or ventriculoatrial shunt might be sufficient to shrink LPS-related EDAC without invasive lumbar surgeries.

Lumboperitoneal shunts for the treatment of idiopathic normal pressure hydrocephalus

The standard of care for idiopathic normal pressure hydrocephalus (iNPH) is placement of a ventriculoperitoneal (VP) shunt. However, VP shunts require intracranial intervention and are associated with notable postoperative complications, with some groups reporting complication rates for VP shunts ranging from 17 to 33%, along with failure rates up to 17.7%. Lumboperitoneal (LP) shunts are an alternative for cerebrospinal fluid diversion that do not require intracranial surgery, thus providing utility in patients where intracranial surgery is not possible or preferred. Here we retrospectively reviewed our 25 patients with LP horizontal-vertical (LP-HV) shunts placement for initial treatment for iNPH from 2014 to 2019. All patients had preoperative gait dysfunction, 16 (64%) had urinary incontinence, and 21 (84%) exhibited cognitive insufficiency. Two weeks post-shunt placement, 23/25 (92%) patients demonstrated improvement in gait, 11/16 (68%) had improvement in incontinence, and 14/21 (66%) had improvement cognitive insufficiency. At six months or greater follow up 13/20 (65%) had improvement in gait, 7/15 (47%) showed improvement in incontinence, and 11/15 (73%) demonstrated improvement in cognitive function. Six patients (24%) required at least one revision of the LP shunt. Shunt malfunctions resulted from CSF leak in one patient, shunt catheter migration in two patients, peritoneal catheter pain in one patient, and clinical symptoms for overdrainage in two patients. Thus, we demonstrate that LP-HV shunt placement is safe and efficacious alternative to VP shunting for iNPH, resulting in notable symptomatic improvement and low risk of overdrainage, and may be considered for patients where cranial approaches should be avoided.

Outcomes Following LSVT BIG in a Person With Idiopathic Normal Pressure Hydrocephalus: A Case Report

BACKGROUND AND PURPOSE

There is no literature exploring physical therapy interventions for individuals with idiopathic normal pressure hydrocephalus (iNPH). There are parallels between symptoms of iNPH and Parkinson disease (PD), suggesting that similar interventions may be beneficial. An approach that promotes recalibration of movements to produce bigger motions (Lee Silverman Voice Treatment BIG [LSVT BIG]) is an evidence-based intervention for individuals with PD, which could potentially improve function in individuals with iNPH. This case report documents functional outcomes of LSVT BIG in an individual with iNPH.

CASE DESCRIPTION

The participant was a 62-year-old man with a 16-year history of iNPH. He demonstrated hypokinesia, impaired balance, and cognitive deficits. These resulted in frequent falls and limited community ambulation.

INTERVENTION

The participant completed the standardized 4-week LSVT BIG program in addition to 5 tune-up sessions 7 months later. Outcome measures included the Berg Balance Scale (BBS), Timed Up and Go (TUG), TUG cognitive and manual, Activities-Specific Balance and Confidence (ABC) scale, Five Times Sit to Stand (5TSTS) test, and a timed floor transfer.

OUTCOMES

Improvements, exceeding minimal detectable change values, were noted on the BBS and the ABC scale immediately following intervention. Scores declined at 4-month follow-up, but BBS scores increased again after the tune-up sessions. Quicker floor transfer times were also noted. There were no changes in TUG, TUG cognitive and manual, or 5TSTS times.

DISCUSSION

Therapists may wish to consider the use of the LSVT BIG program in persons with iNPH; however, a longer program and/or regular tune-up sessions may be necessary for best outcomes.Video Abstract available for more insights from the authors (see the Video, Supplemental Digital Content 1, http://links.lww.com/JNPT/A315).

Lumboperitoneal shunt in idiopathic normal pressure hydrocephalus: a prospective controlled study

OBJECTIVE

In this prospective, controlled, monocentric study, we described the clinical and neuroimaging 12-month follow-up of two parallel cohorts of subjects with idiopathic normal pressure hydrocephalus (iNPH), who did or did not undergo lumboperitoneal shunt (LPS).

METHODS

We recruited 78 iNPH patients. At baseline, subjects underwent clinical and neuropsychological assessments, 3 T magnetic resonance imaging (MRI), and tap test. After baseline, 44 patients (LPS group) opted for LPS implantation, whereas 34 subjects (control group) declined surgery. Both cohorts were then followed up for 12 months through scheduled clinical and neuropsychological evaluations every 6 months. 3 T MRI was repeated at 12-month follow-up.

RESULTS

Gait, balance, and urinary continence improved in the LPS group, without significant influence on cognitive functions. Conversely, gait and urinary continence worsened in the control group. No preoperative MRI parameter was significant outcome predictor after LPS. Of relevance, in responders to LPS, we found postoperative reduction of periventricular white matter (PWM) hyperintensities, which were instead increased in the control group.

CONCLUSIONS

LPS is safe and effective in iNPH. An early surgical treatment is desirable to prevent clinical worsening. Post-surgery decrease of PWM hyperintensities may be a useful MRI marker surrogate for clinical effectiveness of LPS.

Lumboperitoneal Shunt: A New Modified Surgical Technique and a Comparison of the Complications with Ventriculoperitoneal Shunt in a Single Center

Background and objectives: Hydrocephalus remains a disease requiring surgical treatment even in the modern era. Ventriculoperitoneal (VP) shunt placement is the most common treatment, whereas lumboperitoneal (LP) shunts are less commonly used due to initial reports of very high rates of complications. In the present study, we retrospectively reviewed our experience of the new two-stage procedure with LP shunt implantation to assess the complications and the results of this procedure versus VP shunt insertion. Materials and Methods: All patients from a single center who had received LP shunts using a Medtronic Strata device or VP shunts in the past six-year interval were retrospectively reviewed. The LP shunt insertion was a new two-stage procedure. We compared the three major complications and shunt revisions between the two groups, including shunt malfunction, infection, and subdural hematoma. Results: After matching the age and sex of both groups, we included 96 surgery numbers of LP shunts and 192 surgery numbers of VP shunts for comparison. In the LP shunt group, one patient (1.0%) underwent revision of the shunt due to shunt infection. In the VP shunt group, 26 surgeries (13.5%) needed revision, and 11 surgeries (5.7%) had shunt infection. Shunt malfunction occurred in 14 patients (7.3%) and all needed revisions. The revision rate showed statistically significant differences between the LP and VP shunt groups (p < 0.001). Conclusions: The recent improvements in the quality of the LP shunt device and the proficiency of the procedure has made the LP shunt a safer procedure than the VP shunt. The programmable valve can avoid overdrainage complications and reduce the revision rate. With our procedural steps, the LP shunt can be used to decrease the complications and revision rates.

Outcomes and complications of different surgical treatments for idiopathic normal pressure hydrocephalus: a systematic review and meta-analysis

OBJECTIVE

Different CSF diversion procedures (ventriculoperitoneal, ventriculoatrial, and lumboperitoneal shunting) have been utilized for the treatment of idiopathic normal pressure hydrocephalus. More recently, endoscopic third ventriculostomy has been suggested as a reasonable alternative in some studies. The purpose of this study was to perform a systematic review and meta-analysis to assess overall rates of favorable outcomes and adverse events for each of these treatments. An additional objective was to determine the outcomes and complication rates in relation to the type of valve utilized (fixed vs programmable).

METHODS

Multiple databases (PubMed, Ovid MEDLINE In-Process & Other Non-Indexed Citations, Ovid MEDLINE, Ovid Embase, Ovid Cochrane Central Register of Controlled Trials, Ovid Cochrane Database of Systematic Reviews, and Scopus) were searched for studies involving patients with idiopathic ventriculomegaly, no secondary cause of hydrocephalus, opening pressure < 25 mm Hg on high-volume tap or drainage trial, and age > 60 years. Outcomes included the proportion of patients who showed improvement in gait, cognition, and bladder function. Adverse events considered in the analysis included postoperative ischemic/hemorrhagic complications, subdural fluid collections, seizures, need for revision surgery, and infection.

RESULTS

A total of 33 studies, encompassing 2461 patients, were identified. More than 75% of patients experienced improvement after shunting, without significant differences among the different techniques utilized. Overall, gait improvement was observed in 75% of patients, cognitive function improvement in more than 60%, and improvement of incontinence in 55%. Adjustable valves were associated with a reduction in revisions (12% vs 32%) and subdural collections (9% vs 22%) as compared to fixed valves.

CONCLUSIONS

Outcomes did not differ significantly among different CSF diversion techniques, and overall improvement was reported in more than 75% of patients. The use of programmable valves decreased the incidence of revision surgery and of subdural collections after surgery, potentially justifying the higher initial cost associated with these valves.

Improvement in lower urinary tract symptoms across multiple domains following ventriculoperitoneal shunting for idiopathic normal pressure hydrocephalus

AIMS

The purpose of this study was to evaluate the change in lower urinary tract symptoms following ventriculoperitoneal shunting in patients with idiopathic normal pressure hydrocephalus (iNPH).

METHODS

Lower urinary tract symptoms in patients with new-onset iNPH were prospectively evaluated using validated questionnaires from the International Consultation on Incontinence to assess overactive bladder (ICIq-OAB), incontinence (ICIq-UI), and quality of life (ICIq-LUTqol), as well as the American Urological Association Symptom Score bother scale, prior to and following ventriculoperitoneal shunting for iNPH. Sub-analysis was performed based on gender, age, and medical comorbidities.

RESULTS

Twenty-three consecutive patients with new-onset iNPH were evaluated prior to, and following, surgical intervention for iNPH via ventriculoperitoneal shunting. Shunting resulted in a significant improvement in urinary urgency, urge incontinence, ability to perform physical activities, and overall quality of life. Women had improvement across more domains than men following shunting, particularly in terms of urinary urgency and overall quality of life. Younger patients experienced significant improvement in scores following shunting as compared to older patients. Patients with two or more medical comorbidities, as well as those with fewer than two comorbidities, reported a significant improvement in overall quality of life.

CONCLUSIONS

Surgical intervention for iNPH results in significant improvement in urinary symptoms, specifically in terms of urinary urgency and urge incontinence as well as overall quality of life, particularly in women and younger patients.

One-year outcome in patients with idiopathic normal-pressure hydrocephalus: comparison of lumboperitoneal shunt to ventriculoperitoneal shunt

OBJECTIVE

Idiopathic normal pressure hydrocephalus (iNPH) is treated with cerebrospinal fluid shunting, and implantation of a ventriculoperitoneal shunt (VPS) is the current standard treatment. The objective of this study was to compare the efficacy and safety of VPSs and lumboperitoneal shunts (LPSs) for patients with iNPH.

METHODS

The authors conducted a prospective multicenter study of LPS use for patients with iNPH. Eighty-three patients with iNPH (age 60 to 85 years) who presented with ventriculomegaly and high-convexity and medial subarachnoid space tightness on MR images were recruited from 20 neurological or neurosurgical centers in Japan between March 1, 2010, and October 19, 2011. The primary outcome was the modified Rankin Scale (mRS) score 1 year after surgery, and the secondary outcome included scores on the iNPH grading scale (iNPHGS). A previously conducted VPS cohort study with the same inclusion criteria and primary and secondary end points was used as a historical control.

RESULTS

The proportion of patients who achieved a favorable outcome (i.e., improvement of at least 1 point in their mRS score) was 63% (95% CI 51%–73%) and was comparable to values reported with VPS implantation (69%, 95% CI 59%–78%). Using the iNPHGS, the 1-year improvement rate was 75% (95% CI 64%–84%) and was comparable to the rate found in the VPS study (77%, 95% CI 68%–84%). The proportion of patients experiencing serious adverse events (SAEs) and non-SAEs did not differ significantly between the groups at 1 year after surgery (SAEs: 19 [22%] of 87 LPS patients vs 15 [15%] of 100 VPS patients, p = 0.226; non-SAEs: 24 [27.6%] LPS patients vs 20 [20%] VPS patients, p = 0.223). However, shunt revisions were more common in LPS-treated patients than in VPS-treated patients (6 [7%] vs 1 [1%]).

CONCLUSIONS

The efficacy and safety rates for LPSs with programmable valves are comparable to those for VPSs for the treatment of patients with iNPH. Despite the relatively high shunt failure rate, an LPS can be the treatment of choice because of its minimal invasiveness and avoidance of brain injury.

Use of the guidewire for repositioning displaced spinal catheter during lumboperitoneal shunt placement

Background:

During lumboperitoneal shunt operation, we may inadvertently pull and displace the spinal catheter after the catheter placement into the spinal canal. The authors introduce an easy and efficient technique for repositioning a prolapsed catheter into correct place.

Methods:

After the confirmation of cerebrospinal fluid outflow from the end of the catheter, a guidewire for angiogram was gently inserted into the catheter until its tip reached the end of the catheter. The guidewire-inserted catheter was able to be pushed back manually and adequately placed in the spinal canal under the fluoroscope guidance.

Results:

Three patients underwent repositioning using this “rescue wire technique” without complications.

Conclusion:

This “rescue wire technique” is useful for repositioning of the displaced catheter into the spinal canal.

Idiopathic Normal Pressure Hydrocephalus: A Review for General Practitioners

Idiopathic normal pressure hydrocephalus (iNPH) is a potentially reversible neurodegenerative disease commonly characterized by a triad of dementia, gait, and urinary disturbance. Advancements in diagnosis and treatment have aided in properly identifying and improving symptoms in patients. However, a large proportion of iNPH patients remain either undiagnosed or misdiagnosed. Using PubMed search engine of keywords "normal pressure hydrocephalus," "diagnosis," "shunt treatment," "biomarkers," "gait disturbances," "cognitive function," "neuropsychology," "imaging," and "pathogenesis," articles were obtained for this review. The majority of the articles were retrieved from the past 10 years. The purpose of this review article is to aid general practitioners in further understanding current findings on the pathogenesis, diagnosis, and treatment of iNPH.

Intra-bronchial migration of peritoneal catheter of lumboperitoneal shunt

BACKGROUND

A rare case of intra-bronchial migration of peritoneal catheter of lumboperitoneal (LP) shunt was treated under the bronchoscopic and fluoroscopic observation.

CASE DESCRIPTION

A 71-year-old man, who underwent LP shunt installation due to idiopathic normal pressure hydrocephalus a year before, presented with history of high fever and sputum production. Roentgenography and computed tomography of the chest revealed migration of distal end of the peritoneal catheter into the left main bronchus. Migrated catheter was gently extracted through the abdominal wound incision under the bronchoscopic and fluoroscopic observation. Contrast material infused into the catheter did not spread into the pleural cavity. The patient was free of the symptoms within 2 postoperative weeks. Moreover, he underwent the ventriculo-peritoneal shunt surgery 1-month later.

CONCLUSION

This is the first case of the migration of peritoneal catheter of LP shunt into the main bronchus.

[Normal pressure hydrocephalus: A review and practical aspects]

Idiopathic normal pressure hydrocephalus is a chronic disorder affecting the elderly. It is defined by Adams and Hakim's triad in addition to ventricular dilation visible by brain imaging and normal cerebrospinal fluid pressure during lumbar puncture. The objective of this review was to propose a standard of care for idiopathic normal pressure hydrocephalus based on an extensive literature review conducted on 459 articles published over the last 10 years. Those articles were obtained by searching for the keywords "normal pressure hydrocephalus" in the PubMed database and selecting all the articles published in English or in French. The diagnosis of idiopathic normal pressure hydrocephalus is difficult because of commonly associated diseases, such as Alzheimer's disease and microangiopathy. Brain MRI is one of the key procedures to assist in the diagnosis of idiopathic normal pressure hydrocephalus. Indeed, the presence of certain MRI features is highly predictive of a positive tap test and shunt responsiveness. Nevertheless, tap test remains the standard of care for diagnosis. Continuous cerebrospinal fluid drainage test is an alternative because it improves the sensitivity of diagnosis (but is a more complicated test to perform). Alzheimer's biomarkers dosing in the cerebrospinal fluid seems interesting when diagnosis remains uncertain: the presence of Alzheimer's profile of the biological markers is predictive of a lower response to the tap test.

An update on research priorities in hydrocephalus: overview of the third National Institutes of Health-sponsored symposium "Opportunities for Hydrocephalus Research: Pathways to Better Outcomes"

Building on previous National Institutes of Health-sponsored symposia on hydrocephalus research, "Opportunities for Hydrocephalus Research: Pathways to Better Outcomes" was held in Seattle, Washington, July 9-11, 2012. Plenary sessions were organized into four major themes, each with two subtopics: Causes of Hydrocephalus (Genetics and Pathophysiological Modifications); Diagnosis of Hydrocephalus (Biomarkers and Neuroimaging); Treatment of Hydrocephalus (Bioengineering Advances and Surgical Treatments); and Outcome in Hydrocephalus (Neuropsychological and Neurological). International experts gave plenary talks, and extensive group discussions were held for each of the major themes. The conference emphasized patient-centered care and translational research, with the main objective to arrive at a consensus on priorities in hydrocephalus that have the potential to impact patient care in the next 5 years. The current state of hydrocephalus research and treatment was presented, and the following priorities for research were recommended for each theme. 1) Causes of Hydrocephalus-CSF absorption, production, and related drug therapies; pathogenesis of human hydrocephalus; improved animal and in vitro models of hydrocephalus; developmental and macromolecular transport mechanisms; biomechanical changes in hydrocephalus; and age-dependent mechanisms in the development of hydrocephalus. 2) Diagnosis of Hydrocephalus-implementation of a standardized set of protocols and a shared repository of technical information; prospective studies of multimodal techniques including MRI and CSF biomarkers to test potential pharmacological treatments; and quantitative and cost-effective CSF assessment techniques. 3) Treatment of Hydrocephalus-improved bioengineering efforts to reduce proximal catheter and overall shunt failure; external or implantable diagnostics and support for the biological infrastructure research that informs these efforts; and evidence-based surgical standardization with longitudinal metrics to validate or refute implemented practices, procedures, or tests. 4) Outcome in Hydrocephalus-development of specific, reliable batteries with metrics focused on the hydrocephalic patient; measurements of neurocognitive outcome and quality-of-life measures that are adaptable, trackable across the growth spectrum, and applicable cross-culturally; development of comparison metrics against normal aging and sensitive screening tools to diagnose idiopathic normal pressure hydrocephalus against appropriate normative age-based data; better understanding of the incidence and prevalence of hydrocephalus within both pediatric and adult populations; and comparisons of aging patterns in adults with hydrocephalus against normal aging patterns.

Laparoscopic Shunt Revision Avoids Many Complications of Open Shunt Revision and Has Outcomes Similar to First-time Shunt Placement

Open revision of abdominal shunts is associated with increased risk of wound infection, visceral injury, hernia, and shunt complications. We hypothesized that laparoscopic revision mitigates these risks to a level similar to initial (i.e., first-time) shunt placement. This was a single-center, multisurgeon, retrospective cohort study of patients who underwent either laparoscopic initial shunt placement or laparoscopic shunt revision over a 5-year period. Outcomes were operative time, length of stay, and 30-day complication rate. Sixty-nine patients underwent laparoscopic shunt revision and 99 patients underwent laparoscopic initial shunt placement. Operative times were nearly identical (75 vs 73 minutes, P = 0.63). There were no significant differences in blood loss or hospital length of stay. Abdominal complications and total complications did not differ between groups. Laparoscopic shunt revision avoided many of the known complications of open shunt revision and had outcomes similar to initial laparoscopic shunt placement.

Diagnosis and prognosis in idiopathic normal pressure hydrocephalus

Idiopathic normal pressure hydrocephalus (iNPH) is a communicating hydrocephalus, of unknown pathophysiology, characterized by the classical triad of dementia, urinary incontinence, and ataxia. The most popular treatment option is shunt surgery, although it is not a cure. The diagnosis of the disorder is challenging as it may mimic a lot of other neurological conditions and has no distinct biomarker. It becomes even more challenging as majority of the cases are diagnosed by invasive cerebrospinal fluid (CSF) removal tests. However, a careful history taking, a keen and detailed physical examination, and pertinent imaging studies can lead to an early diagnosis. The gait symptoms respond the most to surgery. The predictors deciding the postsurgical prognosis has been discussed. Improved shunting modalities and novel shunt materials with valve adjustments have improved the precision of the shunting procedures. Still we have lot more to achieve in terms of early diagnosis and definitive management of iNPH.

Idiopathic normal-pressure hydrocephalus, cerebrospinal fluid biomarkers, and the cerebrospinal fluid tap test

Cerebrospinal fluid (CSF) biomarkers, including soluble amyloid β-42 (Aβ-42) and phosphorylated-tau (P-tau), reflect core pathophysiological features of Alzheimer's disease (AD). AD is frequently a concomitant pathology in older patients with idiopathic normal-pressure hydrocephalus (iNPH), and somewhat similar altered CSF dynamics exist in both AD and iNPH. We therefore investigated relationships between lumbar CSF biomarkers Aβ-42 and P-tau and clinical parameters in iNPH patients, along with differences in these biomarkers between CSF tap test (CSFTT) responders and non-responders. Thirty-one iNPH patients (14 CSFTT responders and 17 CSFTT non-responders) were included in the final analysis. We found lower CSF Aβ-42 correlated with poor cognitive performance (r=0.687, p<0.001 for Korean Mini Mental State Examination; r=0.568, p=0.001 for Frontal Assessment Battery; r=-0.439, p=0.014 for iNPH grading scale [iNPHGS] cognitive score; r=-0.588, p=0.001 for Clinical Dementia Rating Scale), and lower CSF P-tau correlated with gait dysfunction (r=-0.624, p<0.001 for Timed Up and Go Test; r=-0.652, p<0.001 for 10meter walking test; r=-0.578, p=0.001 for Gait Status Scale; r=-0.543, p=0.002 for iNPHGS gait score). In subgroup analysis, CSF P-tau/Aβ-42 ratios were significantly higher in CSFTT non-responders compared to responders (p=0.027). Two conjectures are suggested. One, CSF biomarkers may play different and characteristic roles in relation to different iNPH symptoms such as cognition and gait. Two, comorbid AD pathology in iNPH patients may affect the response to the CSFTT. Larger studies using combinations of other biomarkers associated with AD would be necessary to evaluate these hypotheses.

A new mechanism of cerebrospinal fluid leakage after lumboperitoneal shunt: a theory of shunt side hole--case report

Cerebrospinal fluid (CSF) overdrainage after lumboperitoneal (LP) shunt placement for the patients with idiopathic normal pressure hydrocephalus (iNPH) is mainly caused by insufficient management of pressure settings of the shunt valve and/or siphon effect of shunt systems induced by the patient's postural changes. We here report a unique case of intracranial hypotension (IH) due to CSF leakage after LP shunt placement in which another mechanism leads to the CSF leakage. A 67-year-old man suffered from persistent headache worsening with postural change 2 months after LP shunt reconstruction for iNPH. Brain computed tomography scan showed bilateral chronic subdural hematomas (CSDH). Lumbar images including shuntography and magnetic resonance imaging showed the tip of the lumbar catheter was spontaneously pulled out close to the dura mater with expansion of the epidural space due to CSF leakage from a shunt side hole of the lumbar catheter to the epidural space. Shunt removal and subsequent irrigation of CSDH improved his headache. CSF leakage in our case differs from those in previous reports, because early and enormous CSF leakage into the epidural space can be explained only by a different mechanism through a side hole just located in the epidural space in our case. We must pay attention to the possibility of this rare cause of IH due to CSF leakage in patients suffering from postural headache after LP shunt placement.

A randomised trial of high and low pressure level settings on an adjustable ventriculoperitoneal shunt valve for idiopathic normal pressure hydrocephalus: results of the Dutch evaluation programme Strata shunt (DEPSS) trial

BACKGROUND

In treating idiopathic normal pressure hydrocephalus (INPH) with a shunt there is always a risk of underdrainage or overdrainage. The hypothesis is tested whether patients treated using an adjustable valve preset at the highest opening pressure leads to comparable good clinical results with less subdural effusions than in a control group with an opening pressure preset at a low pressure level.

METHODS

A multicentre prospective randomised trial was performed on a total of 58 patients suspected of INPH. Thirty patients were assigned to (control) group 1 and received a Strata shunt (Medtronic, Goleta, USA) with the valve preset at a performance level (PL) of 1.0, while 28 patients were assigned to group 2 and received a Strata shunt with the valve preset at PL 2.5. In this group the PL was allowed to be lowered until improvement or radiological signs of overdrainage were met.

RESULTS

Significantly more subdural effusions were observed in the improved patients of group 1. There was no statistically significant difference in improvement between both groups overall.

CONCLUSIONS

On the basis of this multicentre prospective randomised trial it is to be recommended to treat patients with INPH with a shunt with an adjustable valve, preset at the highest opening pressure and lowered until clinical improvement or radiological signs of overdrainage occur although slower improvement and more shunt adjustments might be the consequence.