Long-term 4 Years Follow-up Study of 482 Patients Who Underwent Shunting for Idiopathic Normal Pressure Hydrocephalus -Course of Symptoms and Shunt Efficacy Rates Compared by Age Group

Utility of cortical tissue analysis in normal pressure hydrocephalus

Clinical improvement following neurosurgical cerebrospinal fluid shunting for presumed idiopathic normal pressure hydrocephalus is variable. Idiopathic normal pressure hydrocephalus patients may have undetected Alzheimer's disease-related cortical pathology that confounds diagnosis and clinical outcomes. In this study, we sought to determine the utility of cortical tissue immuno-analysis in predicting shunting outcomes in idiopathic normal pressure hydrocephalus patients. We performed a pooled analysis using a systematic review as well as analysis of a new, original patient cohort. Of the 2707 screened studies, 3 studies with a total of 229 idiopathic normal pressure hydrocephalus patients were selected for inclusion in this meta-analysis alongside our original cohort. Pooled statistics of shunting outcomes for the 229 idiopathic normal pressure hydrocephalus patients and our new cohort of 36 idiopathic normal pressure hydrocephalus patients revealed that patients with Aβ + pathology were significantly more likely to exhibit shunt nonresponsiveness than patients with negative pathology. Idiopathic normal pressure hydrocephalus patients with Alzheimer's disease -related cortical pathology may be at a higher risk of treatment facing unfavorable outcomes following cerebrospinal fluid shunting. Thus, cortical tissue analysis from living patients may be a useful diagnostic and prognostic adjunct for patients with presumed idiopathic normal pressure hydrocephalus and potentially other neurodegenerative conditions affecting the cerebral cortex.

Evolution of neurodegeneration in patients with normal pressure hydrocephalus: a monocentric follow up study

BACKGROUND

The aim of this study was to examine in patients with idiopathic and neurodegenerative normal pressure hydrocephalus (NPH) if motor and cognitive performance as well as changes in biomarkers in cerebrospinal fluid (CSF) evolve differently.

METHODS

41 patients with a typical clinical and MR-/CT-morphological presentation of NPH divided into an Alzheimer-negative (AD-, n = 25) and an Alzheimer-positive (AD+, n = 16) group according to neurodegenerative biomarkers (S100 protein, neuron-specific enolase, β-amyloid 1-42, Tau protein, phospho-Tau, protein-level and CSF pressure) in CSF. Follow-up of cognitive and gait functions before and after a spinal tap of 40-50 ml CSF of up to 49 months. Clinical, motor, neuropsychological and CSF biomarkers were analyzed using a repeated multifactorial analysis of variance (ANOVA) with post-hoc testing.

RESULTS

Gait and neuropsychological performance and CSF biomarkers evolved differently between the AD- and AD+ patients. In particular, the AD+ patients benefited from the spinal tap regarding short-term memory. In contrast, gait parameters worsened over time in the AD+ patients, although they showed a relevant improvement after the first tap.

CONCLUSIONS

The results substantiate the recently reported association between a tap-responsive NPH and CSF changes of Alzheimer disease. Furthermore, they suggest that the AD changes in CSF manifest in an age-related fashion in AD- patients presenting with NPH.

Idiopathic normal pressure hydrocephalus: historical context and a contemporary guide

Idiopathic normal pressure hydrocephalus (NPH) was described in 1965 as a syndrome in which hydrocephalus develops but with a normal cerebrospinal fluid (CSF) pressure, causing shunt-responsive gait apraxia, cognitive impairment and urinary incontinence. Not all patients respond to shunting despite having the clinical syndrome with appropriate radiological features. This has led to considerable debate over subsequent decades regarding idiopathic NPH. It is now understood that asymptomatic communicating hydrocephalus can develop in many healthy older people, and that over time this can develop into a symptomatic state that sometimes responds to CSF shunting, but to a variable extent. This review looks at the historical background of NPH, the use of predictive tests, the current state of clinical evidence for the diagnosis and treatment of idiopathic NPH and the possible underlying causes, to provide a contemporary practical guide for assessing patients with the radiological features of idiopathic NPH.

Rehabilitation effects in idiopathic normal pressure hydrocephalus: a randomized controlled trial

BACKGROUND

Gait-balance disturbances are core symptoms of idiopathic normal pressure hydrocephalus (iNPH). However, the rehabilitation effects of cerebrospinal fluid (CSF) shunting along with other treatment or no further treatment (natural course [NC]) for iNPH are unknown.

OBJECTIVES

This study evaluated whether dynamic equilibrium gait training (DEGT) can improve gait-balance functions after CSF shunting of patients with iNPH compared to standard exercise (SE) and NC. Furthermore, it investigated the incidence of falls.

METHODS

A total of 70 patients with iNPH who underwent CSF shunting were randomly assigned to 6 weeks of DEGT (n = 23), 6 weeks of SE (n = 23), or NC (n = 24). Evaluation was performed at baseline (preoperatively) and at 1 week, 7 weeks (postintervention), and 6 months postoperatively (follow-up). Outcomes were measured using the functional gait assessment (FGA), 10-m walk test, timed up-and-go test, life-space assessment (LSA), and fall incidence.

RESULTS

A total of 65 participants completed the study. During the intention-to-treat analysis, the DEGT group demonstrated significant recovery of gait-balance functions according to only the FGA at postintervention and follow-up compared to the SE and NC groups; however, recovery of the SE group did not differ from that of the NC group. The DEGT group had a significantly lower fall incidence than the other groups at follow-up. Significantly better LSA results were observed for all groups at follow-up compared to baseline; however, no difference in LSA results were observed between groups.

CONCLUSIONS

DEGT in addtion to CSF shunting can facilitate the recovery of gait-balance function and reduce the fall incidence of iNPH patients.

One-year outcome of a lumboperitoneal shunt in older adults with idiopathic normal pressure hydrocephalus

Background

Lumboperitoneal shunt (LPS) is now an effective surgical modality for idiopathic normal pressure hydrocephalus (iNPH), but there is still a lack of clinical data on LPS in older adult iNPH patients in China. We aim to report the shunt effect and the complications of older adult iNPH patients treated with LPS at a single center in Shanghai, China.

Methods

We conducted a retrospective study among adults over 60 years old who were diagnosed as iNPH and treated with LPS from September 2016 to December 2020. The shunt effect was evaluated from two dimensions of functional and symptomatic improvement 3 months and 1 year after surgery, respectively. The potential factors related to the shunt effect one year after surgery were explored by comparing the effect between different subgroups and conducting multivariate logistic regression analysis.

Result

A total of 85 patients were included in this study, ranging from 60 to 93 years old, with an average age of 74.7. The function and symptoms were better both 3 months and 1 year after surgery than before (P < 0.001). At the 1-year postoperation follow-up, the functional and symptomatic improvement rates were 72.9% and 90.6%, respectively. The symptomatic improvement rates of gait, urination, and cognition were 74.1%, 72.9%, and 60.0%, respectively. Multivariate logistic regression analysis showed that improvement in function was much more possible in patients with less than 24 months from symptom onset to surgery (OR = 24.57, P < 0.001) and those with disproportionately enlarged subarachnoid-space hydrocephalus (OR = 5.88, P = 0.048); improvement in gait was also more possible in patients with less than 24 months from symptom onset to surgery (OR = 5.29, P = 0.017); improvement in urination was more possible in patients with diabetes (OR = 4.76, P = 0.019), and improvement in cognition was more possible in patients with preoperative modified Rankin scale level lower than 4 (OR = 3.51, P = 0.040). Minor operation-related complications were seen in 27 patients (31.8%) and severe complications in 6 patients (7.1%).

Conclusion

LPS could improve the function and symptoms of older adult iNPH patients. Early detection, diagnosis, and treatment of the disease could improve the shunt effect of the patients. Older adult iNPH patients with higher age ranges could achieve comparable shunt results compared with younger adults.

Cognitive Impairment in Idiopathic Normal Pressure Hydrocephalus

Idiopathic normal pressure hydrocephalus (iNPH) is a significant cause of the severe cognitive decline in the elderly population. There is no cure for iNPH, but cognitive symptoms can be partially alleviated through cerebrospinal fluid (CSF) diversion. In the early stages of iNPH, cognitive deficits occur primarily in the executive functions and working memory supported by frontostriatal circuits. As the disease progresses, cognition declines continuously and globally, leading to poor quality of life and daily functioning. In this review, we present recent advances in understanding the neurobiological mechanisms of cognitive impairment in iNPH, focusing on (1) abnormal CSF dynamics, (2) dysfunction of frontostriatal and entorhinal-hippocampal circuits and the default mode network, (3) abnormal neuromodulation, and (4) the presence of amyloid-β and tau pathologies.

Acute Occlusion of the Ventriculoperitoneal Shunt Due to Factor XIII Deficiency-related Postoperative Hemorrhage: A Case Report

Coagulation factor XIII (F13) deficiency has been known to be a rare disease with estimated one per two million and one of the possible reasons of postoperative hemorrhage; however, it still remains unpenetrated to physicians. We report a case of acute ventriculoperitoneal (VP) shunt dysfunction due to delayed intraventricular hemorrhage, which could be because of F13 deficiency. The patient was a 48-year-old man with a history of post-meningitis hydrocephalus followed by VP shunt placement. He was found unconscious and transferred to our hospital. A brain CT scan demonstrated shunt malfunction, and he underwent emergency shunt revision. The postoperative course was uneventful except for unexpected neck bruises and continuous minor bleeding from the surgical wound. Three days after surgery, he suddenly became comatose and a CT scan revealed the recurrence of hydrocephalus with newly identified small volume of intraventricular hemorrhage. Emergency shunt revision was performed again. The shunt valve was filled with a hematoma and bloody cerebrospinal fluid was drained from the ventricle. Postoperative blood sample examination demonstrated no abnormal findings but a decreased level of F13 activity, which was thought to be a possible cause of postoperative hemorrhage and the shunt valve hematoma. F13 deficiency causes delayed intracranial hemorrhage 24–48 h after neurological surgery. It can only be diagnosed by checking F13 activity with suspicion. If diagnosed accurately beforehand, unexpected postoperative bleeding can be preventable with proper treatment, such as F13 concentrate and cryoprecipitate. The actual number of the patient with F13 deficiency may be more than estimated ever.

Gait, falls, cognitive function, and health-related quality of life after shunt-treated idiopathic normal pressure hydrocephalus-a single-center study

BACKGROUND

Normal pressure hydrocephalus (NPH) is a neurological disorder, characterized by gait- and balance disturbance, cognitive deterioration, and urinary incontinence, combined with ventricular enlargement. Gait ability, falls, cognitive status, and health-related quality of life pre and post surgery have not previously been studied at Karolinska University Hospital.

METHODS

One hundred and eighteen patients with iNPH that underwent shunt surgery at Karolinska University Hospital during the years from 2016 to 2018 were included. Results of walking tests, test for cognitive function, and self-estimated health-related quality of life, before and 3 months after surgery, were collected retrospectively as a single-center study.

RESULTS

Walking ability, cognitive function, and health-related quality of life significantly increased 3 months after shunt surgery. A positive significant correlation was seen between a higher self-estimated quality of life and walking ability.

CONCLUSIONS

Patients with suspected iNPH treated with shunt surgery at Karolinska University Hospital improved their walking ability and cognitive functioning 3 months after shunt surgery. A positive significant correlation was seen between a higher self-estimated quality of life and walking ability but not with increased cognitive function. We then concluded that the selection of patients for shunting maintained a high standard.

Outcomes of Ventriculoperitoneal Shunt in Patients With Idiopathic Normal-Pressure Hydrocephalus 2 Years After Surgery

Objective: To evaluate the outcomes and prognostic factors of ventriculoperitoneal shunts (VP-shunts) in patients with idiopathic normal-pressure hydrocephalus (iNPH) at 6 months and 2 years after surgery.

Method: We retrospectively analyzed 68 patients admitted to our institute and diagnosed with probable iNPH from January 2017 to March 2021. All patients underwent VP-shunt surgery with a programmable valve, and their outcomes were assessed via the Krauss index and modified Rankin scale (mRS) at 6 months and 2 years post-surgery. Univariate and multivariate regression analysis was performed to identify the prognostic factors.

Results: The mean age of the patients was 71.1 ± 8.4 (mean ± standard deviation) years. On the Krauss improvement index, 6-month follow-up results were available for 68 patients. Of these patients, 91.2% experienced attenuation of their preoperative symptoms, with a mean Krauss index of 0.58 ± 0.27, and 48 patients (70.6%) had a Krauss index ≥0.5. Two-year follow-up results were available for 33 patients; 90.9% of them had sustained improvement, with a Krauss index of 0.54 ± 0.31, and 21 patients (66.3%) had a Krauss index ≥0.5. Thirty-three patients (58%) were living independently after 2 years (mRS 0–2). The outcomes were worse for patients with multiple comorbidities. Neither an increased patient age nor a prolonged history of illness was statistically significant prognostic factors for adverse outcomes of VP-shunt surgery.

Conclusion: Surgical treatment was well-tolerated by patients with iNPH who received VP-shunts. Most patients experienced attenuation of their preoperative symptoms. Multiple concurrent comorbidities should be considered as adverse prognostic factors before shunt insertion in patients with iNPH.

Long term follow-up of shunted idiopathic normal pressure hydrocephalus patients: a single center experience

Idiopathic normal pressure hydrocephalus (iNPH) is a condition characterized by gait disturbance, dementia and/or urinary incontinence and enlarged ventricular system due to disturbance of cerebrospinal fluid (CSF). This study aims to describe the long-term experience with patients with iNPH submitted to ventriculoperitoneal shunt (VPS) with the programmable valve STRATA® (Medtronic). We prospectively selected a cohort of patients with a diagnosis of iNPH from January 2010 to April 2013 in a Brazilian tertiary hospital. All patients underwent clinical evaluation, which consists of the Mini-Mental State Examination and Time Up and Go tests and the application of Japanese Scale for Idiopathic Normal Pressure Hydrocephalus in three stages: prior to the TT, 3 h after the TT and 72 h after the TT. Fifty patients were submitted to VPS and followed. There were 32 men and 18 women. Mean age was 77.1 with standard deviation of 10.9. Follow-up time ranged from 96 to 120 months, with mean of 106 months. After 1 year of follow-up, 42 (83%) patients presented with clinical improvement, decreasing to 62% of patients at mid-term follow-up and 38% of patients at late follow-up. Complications occurred in 18% of subjects, needing reoperation in 16%. Our results show relevant clinical impact of shunting in iNPH patients, decreasing over time. Complications should not be underestimated, reaching up to 18% and demanding reoperation in 16% of cases. Thus, although much has been improved with current shunt technology, it is still important to consider the drawbacks of treatment.

Deficient visuomotor hand coordination in normal pressure hydrocephalus

Objective

To investigate if visuomotor coordination of hand movements is impaired in patients with normal pressure hydrocephalus (NPH) identified by dedicated testing procedures.

Methods

Forty-seven patients admitted for diagnostic workup for suspected NPH were studied prospectively with MRI, testing of cognitive and motor functions, lumbar puncture, and visuomotor coordination of hand movements using the PABLO^R-device before and after a spinal tap of 40–50 ml CSF. Statistical analyses were carried out with repeated measures ANOVA and non-parametric correlation analyses.

Results

Fourteen patients were found to suffer from ideopathic NPH. They were severely impaired in visuomotor control of intermittent arm movements in comparison to patients who were found not to be affected by NPH (n = 18). In the patients with NPH the deficient arm control was improved after the spinal tap in proportion to the improvement of gait. There was no improvement of cognitive and motor functions in the patients not affected by NPH, while the patients with possible NPH (n = 15) showed intermediate deficit and improvement patterns.

Interpretation: Our data underline the importance of a multiparametric assessment of NPH and provide evidence for a motor control deficit in idiopathic NPH involving leg and arm movements. It is suggested that this motor control deficit resulted from an affection of the output tracts from the supplementary motor area in the periventricular vicinity.

Intraventricular infusion test accuracy in predicting short- and long-term outcome of iNPH patients: a 10-year update of a three-decade experience at a single institution

OBJECTIVE

In a previous work, we found that an Intracranial Elastance Index (IEI) ≥0.3 at ventricular infusion test had a high accuracy in predicting shunt response at 6 and 12 months in idiopathic normal pressure hydrocephalus (iNPH). The aim of this study was to verify the accuracy of IEI to predict response to shunt at both short- and long-term follow-up.

METHODS

Retrospective evaluation of 64 patients undergoing ventriculo-peritoneal shunting for iNPH between 2006 and 2015 based on a positive ventricular infusion test (IEI≥0.3). Patients were classified according to Krauss scale and mRS preoperatively, at 1-year and at last follow-up. An improvement of at least one point at Krauss score or at mRS was considered as a good outcome; unchanged or worsened patients were grouped as poor outcome.

RESULTS

Mean follow-up was 6.6 years. Improvement at Krauss scale was seen in 62.5% and 64.3% of patients at 1-year and last follow-up, respectively. Patients in good functional status (mRS≤2) increased from 25 in the preoperative period to 57% at both 1-year and last follow-up. IEI was significantly associated with Krauss (p=0.041) and mRS (p=0.036) outcome at last follow-up. Patients with worse preoperative Krauss and mRS had higher chance to improve but higher overall scores after treatment. At ROC curves, IEI showed a good long-term prediction of change in mRS from first year to last follow-up.

CONCLUSIONS

IEI≥0.3 predicts outcomes at both short- and long-term, with more than 50% of patients being able to look after themselves after 6 years from treatment.

Gaps, Controversies, and Proposed Roadmap for Research in Normal Pressure Hydrocephalus

Idiopathic normal pressure hydrocephalus is considered common but remains underinvestigated. There are no uniformly accepted diagnostic criteria and therapeutic guidelines. We summarize the accumulated evidence regarding the definition, pathophysiology, diagnosis, and treatment of idiopathic normal pressure hydrocephalus, highlighting the many gaps and controversies, including diagnostic challenges, the frequent association with neurodegeneration and vascular disease, and the many unknowns regarding patient selection and outcome predictors. A roadmap to fill these gaps and solve the controversies around this condition is also proposed. More evidence is required with respect to diagnostic criteria, the value of ancillary testing, prospective population-based studies and novel trial designs. Furthermore, a need exists to develop new advanced options in shunt technology. © 2020 International Parkinson and Movement Disorder Society.

Normal Pressure Hydrocephalus Associated with Alzheimer's Disease

OBJECTIVE

The aim was to investigate whether neurodegenerative biomarkers in cerebrospinal fluid (CSF) differentiate patients with suspected normal pressure hydrocephalus (NPH) who respond to CSF drainage from patients who do not respond.

METHODS

Data from 62 consecutive patients who presented with magnetic resonance imaging changes indicative of NPH were studied with regard to cognitive and gait functions before and after drainage of 40-50ml of CSF. Additionally, S100 protein, neuron-specific enolase, β-amyloid protein, tau protein and phospho-tau were determined in CSF. Statistical analyses were carried out with ANOVA and multiple linear regression.

RESULTS

Patients with CSF constellations typical for Alzheimer's disease (n = 28) improved significantly in cognitive and gait-related functions after CSF drainage. In contrast, those patients without a CSF constellation typical for Alzheimer's disease (n = 34) did not improve in cognitive and gait-related functions after CSF drainage. In addition, positive CSF biomarkers for Alzheimer's disease predicted these improvements.

INTERPRETATION

Our data suggest an association between Alzheimer's disease and NPH changes, supporting the recently suggested dichotomy of a neurodegenerative NPH and a true idiopathic NPH, with the latter appearing to be rare. ANN NEUROL 2020;88:703-711.