iNPH Scale Research Articles

Prospective evaluation of flow-regulated valves for idiopathic normal pressure hydrocephalus: 1-year results

ObjectiveOverdrainage and frequent reprogramming are common problems with programmable valves after ventriculoperitoneal shunt surgery for idiopathic normal pressure hydrocephalus (iNPH). Non-adjustable, flow-regulated valves offer a potential solution to these problems, but there is limited data on their efficacy. This study will evaluate neurological improvement and overdrainage rates within one year of treatment with a flow-regulated valve. Patients and MethodsThis prospective study analyzes 45 iNPH patients (median age: 73 years) treated with a flow-regulated valve. Clinical evaluations were performed at baseline, postoperatively, and at 3, 6, and 12 months after surgery. The primary efficacy endpoint was improvement of at least 5 points on the iNPH grading scale at follow-up. The safety endpoint was radiographic evidence of overdrainage. ResultsAll patients presented with gait disturbance, 35 (78 %) had cognitive impairment, and 35 (78 %) had urinary incontinence. The median duration of symptoms was 24 months. The total iNPH score improved in 33/41 (81 %) at 3 months, in 29/34 (85 %) at 6 months, and in 22/29 (64 %) at 12 months. Overall, 40/45 (89 %) patients had a significant improvement on the iNPH scale. Secondary worsening of symptoms after initial improvement was observed in 5 (11 %) patients. Overdrainage occurred in one patient (2 %) requiring surgical evacuation. ConclusionTreatment of iNPH patients with flow-regulated valves resulted in a good neurological outcome with minimal rates of overdrainage. These results are encouraging and justify the clinical use of these valve types.

Symptoms and signs did not predict outcome after surgery: a prospective study of 143 patients with idiopathic normal pressure hydrocephalus.

To determine the utility of symptoms, signs, comorbidities and background variables for the prediction of outcome of treatment in iNPH. A prospective observational study of consecutively included iNPH patients, who underwent neurological, physiotherapeutic and neuropsychological assessments before and after shunt surgery. The primary outcome measure was the total change on the iNPH scale, and patients were defined as improved postoperatively if they had improved by at least five points on that scale. 143 iNPH patients were included, and 73% of those were improved after surgery. None of the examined symptoms or signs could predict which patients would improve after shunt surgery. A dominant subjective complaint of memory problems at baseline was predictive of non-improvement. The reported comorbidities, duration of symptoms and BMI were the same in improved and non-improved patients. Each of the symptom domains (gait, neuropsychology, balance, and continence) as well as the total iNPH scale score improved significantly (from median 53 to 69, p < 0.001). The proportions of patients with shuffling gait, broad-based gait, paratonic rigidity and retropulsion all decreased significantly. This study confirms that the recorded clinical signs, symptoms, and impairments in the adopted clinical tests are characteristic findings in iNPH, based on that most of them improved after shunt surgery. However, our clinical data did not enable predictions of whether patients would respond to shunt surgery, indicating that the phenotype is unrelated to the reversibility of the iNPH state and should mainly support diagnosis. Absence of specific signs should not be used to exclude patients from treatment.

Noninvasive assessment of glymphatic dysfunction in idiopathic normal pressure hydrocephalus with diffusion tensor imaging.

Diffusion tensor imaging (DTI) along the perivascular space (ALPS) (DTI-ALPS)-by calculating the ALPS index, a ratio accentuating water diffusion in the perivascular space-has been proposed as a noninvasive, indirect MRI method for assessing glymphatic function. The main aim of this study was to investigate whether DTI-ALPS would reveal glymphatic dysfunction in idiopathic normal pressure hydrocephalus (iNPH) and whether the ALPS index was associated with disease severity. Thirty iNPH patients (13 men; median age 77 years) and 27 healthy controls (10 men; median age 73 years) underwent MRI and clinical assessment with the Timed Up and Go test (TUG) and Mini-Mental State Examination (MMSE); only the patients were evaluated with the Hellström iNPH scale. MRI data were analyzed with the DTI-ALPS method and Radscale screening tool. iNPH patients showed significantly lower mean ALPS index scores compared with healthy controls (median [interquartile range] 1.09 [1.00-1.15] vs 1.49 [1.36-1.59], p < 0.001). Female healthy controls showed significantly higher ALPS index scores than males in both hemispheres (e.g., right hemisphere 1.62 [1.47-1.67] vs 1.33 [1.14-1.41], p = 0.001). This sex difference was not seen in iNPH patients. The authors found a moderate exponential correlation between mean ALPS index score and motor function as measured with time required to complete TUG (r = -0.644, p < 0.001), number of steps to complete TUG (r = -0.571, p < 0.001), 10-m walk time (r = -0.637, p < 0.001), and 10-m walk steps (r = -0.588, p < 0.001). The authors also found a positive linear correlation between mean ALPS index score and MMSE score (r = 0.416, p = 0.001). Simple linear regression showed a significant effect of diagnosis (B = -0.39, p < 0.001, R2 = 0.459), female sex (B = 0.232, p = 0.002, R2 = 0.157), and Evans index (B = -4.151, p < 0.001, R2 = 0.559) on ALPS index. Multiple linear regression, including diagnosis, sex, and Evans index score, showed a higher predictive value (R2 = 0.626) than analysis of each of these factors alone. The ALPS index, which was significantly decreased in iNPH patients, could serve as a marker of disease severity, both clinically and in terms of neuroimaging. However, it is important to consider the significant influence of biological sex and ventriculomegaly on the ALPS index, which raises the question of whether the ALPS index solely reflects glymphatic function or if it also encompasses other types of injury. Future studies are needed to address potential confounding factors and further validate the ALPS method.

Association between ventricular CSF biomarkers and outcome after shunt surgery in idiopathic normal pressure hydrocephalus

IntroductionThe relationship between neurochemical changes and outcome after shunt surgery in idiopathic normal pressure hydrocephalus (iNPH), a treatable dementia and gait disorder, is unclear. We used baseline ventricular CSF to explore associations to outcome, after shunting, of biomarkers selected to reflect a range of pathophysiological processes.MethodsIn 119 consecutive patients with iNPH, the iNPH scale was used before and after shunt surgery to quantify outcome. Ventricular CSF was collected perioperatively and analyzed for biomarkers of astrogliosis, axonal, amyloid and tau pathology, and synaptic dysfunction: glial fibrillary acidic protein (GFAP), chitinase-3-like protein 1 (YKL40/CHI3L1), monocyte chemoattractant protein-1 (MCP-1) neurofilament light (NfL), amyloid beta 38 (Aβ38), Aβ40, Aβ42, amyloid beta 42/40 ratio (Aβ42/40), soluble amyloid precursor protein alfa (sAPPα), sAPPβ, total tau (T-tau), phosphorylated tau (P-tau), growth-associated protein 43 (GAP43), and neurogranin.ResultsThe neurogranin concentration was higher in improved (68%) compared to unimproved patients (median 365 ng/L (IQR 186–544) vs 330 (205–456); p = 0.046). A linear regression model controlled for age, sex and vascular risk factors including neurogranin, T-tau, and GFAP, resulted in adjusted R2 = 0.06, p = 0.047. The Aβ42/40 ratio was bimodally distributed across all samples, as well as in the subgroups of improved and unimproved patients but did not contribute to outcome prediction. The preoperative MMSE score was lower within the low Aβ ratio group (median 25, IQR 23–28) compared to the high subgroup (26, 24–29) (p = 0.028). The T-Tau x Aβ40/42 ratio and P-tau x Aβ40/42 ratio did not contribute to shunt response prediction. The prevalence of vascular risk factors did not affect shunt response.DiscussionA higher preoperative ventricular CSF level of neurogranin, which is a postsynaptic marker, may signal a favorable postoperative outcome. Concentrations of a panel of ventricular CSF biomarkers explained only 6% of the variability in outcome. Evidence of amyloid or tau pathology did not affect the outcome.

Plasma and cerebrospinal fluid concentrations of neurofilament light protein correlate in patients with idiopathic normal pressure hydrocephalus

BackgroundNeurofilament light chain protein (NFL), a marker of neuronal axonal degeneration, is increased in cerebrospinal fluid (CSF) of patients with idiopathic normal pressure hydrocephalus (iNPH). Assays for analysis of NFL in plasma are now widely available but plasma NFL has not been reported in iNPH patients. Our aim was to examine plasma NFL in iNPH patients and to evaluate the correlation between plasma and CSF levels, and whether NFL levels are associated with clinical symptoms and outcome after shunt surgery.MethodsFifty iNPH patients with median age 73 who had their symptoms assessed with the iNPH scale and plasma and CSF NFL sampled pre- and median 9 months post-operatively. CSF plasma was compared with 50 healthy controls (HC) matched for age and gender. Concentrations of NFL were determined in plasma using an in-house Simoa method and in CSF using a commercially available ELISA method.ResultsPlasma NFL was elevated in patients with iNPH compared to HC (iNPH: 45 (30–64) pg/mL; HC: 33 (26–50) (median; Q1–Q3), p = 0.029). Plasma and CSF NFL concentrations correlated in iNPH patients both pre- and postoperatively (r = 0.67 and 0.72, p < 0.001). We found only weak correlations between plasma or CSF NFL and clinical symptoms and no associations with outcome. A postoperative NFL increase was seen in CSF but not in plasma.ConclusionsPlasma NFL is increased in iNPH patients and concentrations correlate with CSF NFL implying that plasma NFL can be used to assess evidence of axonal degeneration in iNPH. This finding opens a window for plasma samples to be used in future studies of other biomarkers in iNPH. NFL is probably not a very useful marker of symptomatology or for prediction of outcome in iNPH.

The effect of shunt surgery on corticospinal excitability in idiopathic normal pressure hydrocephalus: a transcranial magnetic stimulation study

BackgroundIdiopathic normal pressure hydrocephalus (iNPH) is a multifactorial disease presenting with a classical symptom triad of cognitive decline, gait disturbance and urinary incontinence. The symptoms can be alleviated with shunt surgery but the etiology of the symptoms remains unclear. Navigated transcranial magnetic stimulation (nTMS) was applied to characterize corticospinal excitability and cortical motor function before and after shunt surgery in order to elucidate the pathophysiology of iNPH. We also aimed to determine, whether nTMS could be applied as a predictive tool in the pre-surgical work-up of iNPH.Methods24 patients with possible or probable iNPH were evaluated at baseline, after cerebrospinal fluid drainage test (TAP test) and three months after shunt surgery (follow-up). Symptom severity was evaluated on an iNPH scale and with clinical tests (walking test, Box & Block test, grooved pegboard). In the nTMS experiments, resting motor threshold (RMT), silent period (SP), input–output curve (IO-curve), repetition suppression (RS) and mapping of cortical representation areas of hand and foot muscles were assessed.ResultsAfter shunt surgery, all patients showed improved performance in gait and upper limb function. The nTMS parameters showed an increase in the RMTs (hand and foot) and the maximum value of the IO-curve increased in subject with a good surgical outcome. The improvement in gait correlated with an increase in the maximum value of the IO-curve. SP, RS and mapping remained unchanged.ConclusionThe excitability of the motor cortex and the corticospinal tract increased in iNPH patients after shunt surgery. A favorable clinical outcome of shunt surgery is associated with a higher ability to re-form and maintain neuronal connectivity.

The diagnostic value of the pulsatility curve to predict shunt responsiveness in patients with idiopathic normal pressure hydrocephalus

ObjectiveThe aim of this study was to investigate the diagnostic accuracy of the pulsatility curve to predict shunt response in patients with idiopathic normal pressure hydrocephalus (iNPH).MethodsLumbar cerebrospinal fluid dynamics were derived from an automatic lumbar infusion test (LIT) protocol. All patients were treated with ventriculoperitoneal shunting and re-examined 6 months after shunting. Patient demographics and outcomes were gathered in a prospective, electronic database that spanned from January 2012 to January 2020. A validated iNPH scale was used to assess patients preoperatively and 6 months postoperatively. The relationship of the relative pulse pressure coefficient (RPPC), delta amplitude, successful lowering of amplitude, and the pressure-value at a hypothetical amplitude of zero (P0), resistance to outflow (Rout), and outcome, were assessed using receiver operating characteristic (ROC) curves.ResultsWe included 38 patients. The RPPC, delta amplitude, successful lowering of amplitude, and P0 parameters did not predict shunt response. Mean P0 was 0.5 (IQR 0.4–0.9) in improved patients and 0.4 (IQR 0–1.2) in non-improved patients. The delta amplitude was 0.16 kPa (IQR 0.10–0.23) in improved patients and 0.18 kPa (IQR 0.11–0.24) in non-improved patients. Furthermore, we found a technical failure rate of pulsatility curve measurements of 32%.ConclusionPulsatility curve results were not suitable in predicting shunt response in our cohort. The diagnostic value of LIT in case of normal pressure hydrocephalus should be subject to more rigorous research.

White matter changes should not exclude patients with idiopathic normal pressure hydrocephalus from shunt surgery

IntroductionWhite matter changes (WMC) on brain imaging can be classified as deep white matter hyperintensities (DWMH) or periventricular hyperintensities (PVH) and are frequently seen in patients with idiopathic normal pressure hydrocephalus (iNPH). Contradictory results have been reported on whether preoperative WMC are associated with outcome after shunt surgery in iNPH patients. The aim of this study was to investigate any association between DWMH and PVH and shunt outcome in patients with iNPH, using magnetic resonance volumetry.MethodsA total of 253 iNPH patients operated with shunt surgery and clinically assessed before and 12 months after surgery were included. All patients were investigated preoperatively with magnetic resonance imaging of the brain. The volumes of DWMH and PVH were quantified on fluid-attenuated inversion recovery images using an in-house semi-automatic volumetric segmentation software (SmartPaint). Shunt outcome was defined as the difference in symptom score between post- and preoperative investigations, measured on the iNPH scale, and shunt response was defined as improvement with ≥ 5 points.ResultsOne year after shunt surgery, 51% of the patients were improved on the iNPH scale. When defining improvement as ≥ 5 points on the iNPH scale, there was no significant difference in preoperative volume of WMC between shunt responders and non-responders. If outcome was determined by a continuous variable, a larger volume of PVH was negatively associated with postoperative change in the total iNPH scale (p < 0.05) and negatively associated with improvement in gait (p < 0.01) after adjusting for age, sex, waiting time for surgery, preoperative level of symptoms, Evans’ index, and disproportionately enlarged subarachnoid space hydrocephalus. The volume of DWMH was not associated with shunt outcome.ConclusionsAn association between outcome after shunt surgery and volume of PVH was seen, but there was no difference between shunt responders and non-responders in the volumes of DWMH and PVH. We conclude that preoperative assessment of WMC should not be used to exclude patients with iNPH from shunt surgery.

Higher levels of neurofilament light chain and total tau in CSF are associated with negative outcome after shunt surgery in patients with normal pressure hydrocephalus

BackgroundLumbar punctures are a common examination in the work-up of patients with idiopathic normal pressure hydrocephalus (iNPH) and cerebrospinal fluid (CSF) biomarkers should therefore be available for use in selection of shunt candidates. The aim of this study was to investigate if CSF biomarkers are associated with outcome after shunt surgery alone or in combination with comorbidity and imaging markers, and investigate associations between CSF biomarkers and symptoms.MethodsPreoperative CSF biomarkers were analyzed in 455 patients operated with shunt surgery for iNPH at a single center during 2011–2018. Symptoms before and 12 months after shunt surgery were graded with the Swedish iNPH scale. Neurofilament light chain protein (NfL), total tau (T-tau), phosphorylated tau (P-tau) and amyloid beta1-42 (Aβ1-42) CSF levels were measured. Evans’ index and disproportionately enlarged subarachnoid space hydrocephalus were measured on preoperative CT-scans. Preoperative evaluation and follow-up 12 months after shunt surgery were available in 376 patients.ResultsHigher levels of NfL and T-tau were associated with less improvement after shunt surgery (β = − 3.10, p = 0.016 and β = − 2.45, p = 0.012, respectively). Patients whose symptoms deteriorated after shunt surgery had higher preoperative levels of NfL (1250 ng/L [IQR:1020–2220] vs. 1020 [770–1649], p < 0.001) and T-tau (221 ng/L [IQR: 159–346] vs. 190 [135–261], p = 0.0039) than patients with postoperative improvement on the iNPH scale. Among the patients who improved ≥ 5 levels on the iNPH scale (55%), NfL was abnormal in 22%, T-tau in 14%, P-tau in 6% and Aβ1-42 in 45%, compared with normal reference limits. The inclusion of CSF biomarkers, imaging markers and comorbidity in multivariate predictive Orthogonal Projections to Latent Structures (OPLS) models to did not improve predictability in outcome after shunt surgery.ConclusionsHigher levels of T-tau and NfL were associated with a less favorable response to shunt surgery, suggesting a more active neurodegeneration in this group of patients. However, CSF levels of these biomarkers can be elevated also in patients who respond to shunt surgery. Thus, none of these CSF biomarkers, alone or used in combination, are suitable for excluding patients from surgery.

The timed up and go test in idiopathic normal pressure hydrocephalus: a Nationwide Study of 1300 patients

BackgroundThe aim of this study was to describe the outcome measure timed up and go (TUG) in a large, nationwide cohort of patients with idiopathic normal pressure hydrocephalus (iNPH) pre- and post-operatively. Furthermore, to compare the TUG test to the 10-m walk test (10MWT), the iNPH scale, the modified Rankin scale (mRS) and the Mini Mental State Examination (MMSE), which are commonly applied in clinical assessment of iNPH.MethodsPatients with iNPH (n = 1300), registered in the Swedish Hydrocephalus Quality Registry (SHQR), were included. All data were retrieved from the SHQR except the 10MWT, which was collected from patient medical records. Clinical scales were examined pre- and 3 months post-operatively. Data were dichotomised by sex, age, and preoperative TUG time.ResultsPreoperative TUG values were 19.0 [14.0–26.0] s (median [IQR]) and 23 [18–30] steps. Post-operatively, significant improvements to 14.0 [11.0–20.0] s and 19 [15–25] steps were seen. TUG time and steps were higher in women compared to men (p < 0.001) but there was no sex difference in improvement rate. Worse preoperative TUG and younger age favoured improvement. TUG was highly correlated to the 10MWT, but correlations of post-operative changes were only low to moderate between all scales (r = 0.22–0.61).ConclusionsThis study establishes the distribution of TUG in iNPH patients and shows that the test captures important clinical features that improve after surgery independent of sex and in all age groups, confirming the clinical value of the TUG test. TUG performance is associated with performance on the 10MWT pre- and post-operatively. However, the weak correlations in post-operative change to the 10MWT and other established outcome measures indicate an additional value of TUG when assessing the effects of shunt surgery.

Waiting time for surgery influences the outcome in idiopathic normal pressure hydrocephalus \u2014 a population-based study

IntroductionIdiopathic normal pressure hydrocephalus (iNPH) is a disease that comes with a great impact on the patient’s life. The only treatment for iNPH, which is a progressive disease, is shunt surgery. It is previously indicated that early intervention might be of importance for the outcome.AimTo investigate if a longer waiting time for surgery, negatively influences the clinical outcome.MethodsEligible for this study were all iNPH patients (n = 3007) registered in the Swedish Hydrocephalus Quality Registry (SHQR) during 1st of January 2004–12th of June 2019. Waiting time, defined as time between the decision to accept a patient for surgery and shunt surgery, was divided into the intervals ≤ 3, 3.1–5.9 and ≥ 6 months. Clinical outcome was assessed 3 and 12 months after surgery using the modified iNPH scale, the Timed Up and Go (TUG) test and the mini mental state examination (MMSE).ResultsThree months after surgery, 57% of the patients with ≤ 3 months waiting time showed an improvement in modified iNPH scale (≥ 5 points) whereas 52% and 46% of patients with 3.1–5.9 and ≥ 6 months waiting time respectively improved (p = 0.0115). At 12 months of follow-up, the corresponding numbers were 61%, 52% and 51% respectively (p = 0.0536).ConclusionsThis population-based study showed that in patients with iNPH, shunt surgery should be performed within 3 months of decision to surgery, to attain the best outcome.

Physical exercise and goal attainment after shunt surgery in idiopathic normal pressure hydrocephalus: a randomised clinical trial

BackgroundRehabilitation in iNPH is suggested to be an important factor to improve patients’ functions but there are lack of clinical trials evaluating the effect of rehabilitation interventions after shunt surgery in iNPH. The objective of this study was to evaluate the effect of a physical exercise programme and goal attainment for patients with idiopathic normal pressure hydrocephalus (iNPH) after surgery compared to a control group.MethodsThis was a dual centre randomised controlled trial with assessor blinding, intention-to-treat (ITT) and per protocol (PP) analysis. Individuals diagnosed with iNPH scheduled to undergo shunt surgery at the Linköping University Hospital in Linköping and Sahlgrenska University Hospital in Gothenburg, Sweden were consecutively eligible for inclusion. Inclusion was conducted between January 2016 and June 2018. The patients were randomised 1:1 using sequentially numbered sealed envelopes to receive either written exercise information (control group) or written information and an additional supervised high-intensity, functional exercise programme (HIFE) executed twice weekly over 12 weeks (exercise group). Preoperatively, the patients set individual goals. The primary outcome was change from baseline in the total iNPH scale score at the post-intervention follow-up. Secondary outcomes were goal attainment, and change in the separate scores of gait, balance, neuropsychology and continence and in the total score after 6 months.ResultsIn total, 127 participants were randomised to the exercise group (n = 62) and to the control group (n = 65). In the ITT population (exercise group, n = 50; control group, n = 59), there were no between-group differences in the primary outcome, but the attrition rate in the exercise group was high. The exercise group improved more than the control group in the balance domain scores after 6 months. Post-intervention, the PP exercise population achieved their set goals to a greater extent than the controls.ConclusionsAn additional effect of the 12-week HIFE-programme on the overall improvement according to the iNPH-scale after shunt surgery in iNPH was not shown. This could be due to high attrition rate. However, the long-term effect on balance and higher goal achievement indicate beneficial influences of supervised physical exercise.Trial registration clinicaltrials.gov, NCT02659111. Registered 20 January 2016, https://clinicaltrials.gov/ct2/show/NCT02659111

Assessment of neurological symptoms in adult hydrocephalus occlusus. A pilot study

BackgroundComprehensively describe and compare (pre⁄postoperatively) the clinical symptomatology in adult non-communicated hydrocephalus. Associated hydrocephalus signs were analyzed with the idiopathic Normal Pressure Hydrocephalus Scale (iNPH Scale). A standardized clinical scale for non-communicated hydrocephalus is currently not in use. MethodsTen patients with hydrocephalus occlusus (HO) were analyzed. Hydrocephalus signs were examined with the iNPH Scale in gait, neuropsychology, continence, and balance before and three months after treatment with shunt operation or third endoscopic ventriculostomy. ResultsPatients significantly improved in iNPH total score (25.8%) and gait score (35.4%) three months after neurosurgical intervention. Domain scores in neuropsychology, continence, and balance reached statistical trends (p ≤ 0.066). Most clinical symptoms and signs at baseline improved after surgery (dizziness, lapse of concentration, gait instability, and headache). ConclusionPatients with non-communicated HO also showed classical hydrocephalus symptoms as communicated in iNPH patients. The iNPH Scale allows a structured neurological assessment over the disease’s progress and surgical intervention. Further studies with a larger patient samples are necessary to support our results.

Evaluating the cerebrospinal fluid tap test with the Hellstr\xf6m iNPH scale for patients with idiopathic normal pressure hydrocephalus

BackgroundThe cerebrospinal fluid tap test (CSF TT) is used for selecting shunt surgery candidates among patients with idiopathic normal pressure hydrocephalus (iNPH). We aimed to evaluate the predictive value of the CSF TT, by using the Hellström iNPH scale for shunted iNPH patients with a standardized method.MethodsOne hundred and sixteen shunt-operated iNPH patients were retrospectively included in this study. The gait and balance domains in the iNPH scale were used as outcome measures for the CSF TT and the total iNPH scale score as the postoperative outcome. A positive response to CSF TT was defined as a change of ≥ 5 points in the gait domain and ≥ 16 points in the balance domain. Differences between CSF TT responders and non-responders, sensitivity, specificity, positive and negative predictive values, accuracy, and correlations between changes from baseline to post CSF TT and from baseline to the postoperative follow-up, were calculated.ResultsIn the CSF TT there were 63.8% responders in the gait domain and correspondingly 44.3% in the balance domain. CSF TT responders had a significantly better postoperative outcome in the total scale score (gait P ≤ 0.001, balance P ≤ 0.012) and gait CSF TT responders improved more in gait (P ≤ 0.001) and balance CSF TT responders in balance (P ≤ 0.001). No differences between CSF TT gait or balance responders could be found in neuropsychological or urinary continence assessments postoperatively. The sensitivity and specificity of the CSF TT and the outcome of the total iNPH scale score postoperatively were 68.1% and 52.0% for gait and 47.8% and 68.0% for balance, respectively.ConclusionsThe CSF TT, with the Hellström iNPH scale as the outcome measure, has clear limitations in predicting postoperative results. The gait domain may be used to predict outcomes for gait, but the balance domain is too insensitive.

A comprehensive clinico-radiological, neuropsychological and biomechanical analysis approach to patients with idiopathic normal pressure hydrocephalus

BackgroundA systematic approach to patients with suspected idiopathic normal pressure hydrocephalus (iNPH) is essential to recognize the subset of patients who may benefit from ventriculoperitoneal shunt surgery (VPS). Quantitative biomechanical analysis of gait and balance (QBAGB) may help objectify the response to the cerebrospinal fluid tap test (CSF-TT) and VPS outcome after 3 months and support identification of candidates for VPS. MethodsWe retrospectively reviewed data from all patients with probable iNPH who 1) underwent clinico-radiological and neuropsychological assessments using validated scales (iNPH Scale and iNPH Radscale) at our centre in the period from January to December 2018; and 2) had completed QBAGB before CSF-TT (‘baseline’), shortly after CSF-TT, and at three months after either VPS or conservative treatment. ResultsAt the time-points ‘after CSF-TT’ and ‘3 months’, patients with iNPH and VPS (n = 11) significantly improved on the Kiefer Scale score, iNPH Scale total score and gait domain score, as well as in gait velocity and step length measured by QBAGB. In contrast, patients without surgery (n = 10) had unchanged iNPH Scale scores and motor performance throughout. Using data from all patients, we calculated cut-off levels for substantial improvements in gait velocity, step length, and the iNPH Scale domain gait score at the time-point ‘after CSF-TT’. ConclusionQBAGB helps to objectify the response to CSF-TT to select candidates for VPS and corroborates clinico-radiological and neuropsychological data derived from validated scales. The QBAGB cut-off values for substantial improvement after CSF-TT need further elucidation in larger, preferably prospective studies.

Negative predictors of shunt surgery outcome in normal pressure hydrocephalus.

The prevalence of idiopathic normal pressure hydrocephalus (iNPH) and vascular comorbidity increases with age. It has not been clarified if high age and vascular disease are negative predictors of shunt surgery outcome in patients with iNPH. The aim of this study was to investigate the impact of high age and vascular comorbidity on outcome after shunt surgery in patients with iNPH. All 332 patients with iNPH who were treated with shunts between 2011 and 2015 at a single centre were consecutively included. Hellström iNPH scale, without the neuropsychological tests, was calculated preoperatively and at follow-up 12months after shunt surgery. Outcome was defined as the difference between the post-operative and preoperative iNPH scale scores. A multivariable model was used to investigate the predictive effects of age and vascular comorbidity on shunt surgery outcome. In a multivariable analysis of covariance (ANCOVA) with post-operative outcome as the dependent variable, increasing age (years, B=-0.63, P<.001) and history of ischaemic stroke (B=-10.06, P=.0038) were negative predictors of shunt surgery outcome after controlling for waiting time for surgery, symptom severity at preoperative control, presence of diabetes mellitus, hypertension, hyperlipidaemia, history of myocardial infarction, duration of symptoms and shunt complications. High age and established cerebrovascular disease are associated with less favourable outcome after shunt surgery in patients with iNPH.

The idiopathic normal-pressure hydrocephalus Radscale: a radiological scale for structured evaluation.

Despite the important role of imaging in diagnosing idiopathic normal-pressure hydrocephalus (iNPH), a structured overall assessment of radiological signs is still lacking. The purpose of this study was to construct a radiological scale, composed of morphological signs of iNPH, and compare it with clinical symptoms. In this prospective, population-based study of iNPH, 168 individuals (93 females) [mean age 75 (range 66-92)years] underwent computed tomography of the brain and a neurological examination with assessment of clinical symptoms according to Hellström's iNPH scale. Two radiologists, blinded to clinical data, independently evaluated and measured eight radiological parameters, i.e. Evans' index, callosal angle, size of temporal horns, narrow high-convexity sulci, dilated Sylvian fissures, focally dilated sulci, peri-ventricular hypodensities and bulging of the lateral ventricular roof. In a linear regression model, all parameters except ventricular roof bulging were significantly associated with clinical iNPH symptoms. The seven remaining parameters were summarized into a total iNPH Radscale score ranging from 0 to 12. There was a significant correlation (r=0.55, P<0.001) between the total iNPH Radscale score and clinical symptoms. The inter-rater agreement for the included radiological parameters was high (intraclass correlation, 0.74-0.97). The iNPH Radscale may become a valuable diagnostic screening tool, allowing a structured radiological assessment. A high iNPH Radscale score together with clinical symptoms should raise suspicion of iNPH, motivating further evaluation for shunt surgery.

Brain tissue Aβ42 levels are linked to shunt response in idiopathic normal pressure hydrocephalus.

The authors conducted a study to test if the cortical brain tissue levels of soluble amyloid beta (Aβ) reflect the propensity of cortical Aβ aggregate formation and may be an additional factor predicting surgical outcome following idiopathic normal pressure hydrocephalus (iNPH) treatment. Highly selective ELISAs (enzyme-linked immunosorbent assays) were used to quantify soluble Aβ40, Aβ42, and neurotoxic Aβ oligomers/protofibrils, associated with Aβ aggregation, in cortical biopsy samples obtained in patients with iNPH (n = 20), sampled during ventriculoperitoneal (VP) shunt surgery. Patients underwent pre- and postoperative (3-month) clinical assessment with a modified iNPH scale. The preoperative CSF biomarkers and the levels of soluble and insoluble Aβ species in cortical biopsy samples were analyzed for their association with a favorable outcome following the VP shunt procedure, defined as a ≥ 5-point increase in the iNPH scale. The brain tissue levels of Aβ42 were negatively correlated with CSF Aβ42 (Spearman’s r = -0.53, p < 0.05). The Aβ40, Aβ42, and Aβ oligomer/protofibril levels in cortical biopsy samples were higher in patients with insoluble cortical Aβ aggregates (p < 0.05). The preoperative CSF Aβ42 levels were similar in patients responding (n = 11) and not responding (n = 9) to VP shunt treatment at 3 months postsurgery. In contrast, the presence of cortical Aβ aggregates and high brain tissue Aβ42 levels were associated with a poor outcome following VP shunt treatment (p < 0.05). Brain tissue measurements of soluble Aβ species are feasible. Since high Aβ42 levels in cortical biopsy samples obtained in patients with iNPH indicated a poor surgical outcome, tissue levels of Aβ species may be associated with the clinical response to shunt treatment.

CORRELATION BETWEEN THE CLINICAL, NEUROIMAGING CHARACTERS AND THE CEREBROSPINAL FLUID TAP TEST RESPONSE IN CHINESE IDIOPATHIC NORMAL PRESSURE HYDROCEPHALUS PATIENTS

In order to be helpful for the diagnosis and prediction of the shunting surgery outcome in Chinese idiopathic normal pressure hydrocephalus patients, we herein were to explore the correlation between the clinical, neuroimaging characteristics and the cerebrospinal fluid tap test response. 43 iNPH patients in PUMCH from 2013–2015 were included. All patients were evaluated using MMSE, MOCA, ADL, iNPH scale, underwent 1.5T head MRI scan and a cerebrospinal fluid tap with removal of 30 ml of CSF. The evaluations prior to and posterior to CSF tap test included the 10m walking time and steps, TMT-A, digital symbol and STROOP test. Two experienced neurologists were responsible for the adjustment of the CSF tap test response. The clinical and neuroimaging parameters of iNPH patients were analyzed between the CSF tap test responders and non-responders. Compared with non-responders, the patients of CSF tap test responders had more male patients (male: female 20:4 vs. 9:10, p= 0.021), longer walking disturbance history ((1040.13±708.33) days vs. (597.06±527.7) days, p= 0.035), lower baseline cognitive tests z score (-15.731±16.537 vs. -4.236±8.280, p= 0.041) and more periventricular white matter lesions (p= 0.033). We report some clinical and neuroimaging characters of iNPH patients which were a little different from those have been reported. Our limitation is that the shunting result hadn't been analyzed because of the limited number of patients. However the results indicated that the patients with the longer duration, the lower cognitive tests score and the prominent white matter lesions should not be excluded for the shunting surgery.

Incidence and outcome of surgery for adult hydrocephalus patients in Sweden

Object: To present population-based and age related incidence of surgery and clinical outcome for adult patients operated for hydrocephalus, registered in the Swedish Hydrocephalus Quality Registry (SHQR).Methods: All patients registered in SHQR during 2004–2011 were included. Data on age, gender, type of hydrocephalus and type of surgery were extracted as well as three months outcome for patients with idiopathic normal pressure hydrocephalus (iNPH).Results: The material consisted of 2360 patients, 1229 men and 1131 women, age 63.8 ± 14.4 years (mean ± standard deviation (SD)). The mean total incidence of surgery was 5.1 ± 0.9 surgeries/100,000/year; 4.7 ± 0.9 shunt surgeries and 0.4 ± 0.1 endoscopic third ventriculostomies. For iNPH, secondary communicating hydrocephalus and obstructive hydrocephalus, the incidence of surgery was 2.2 ± 0.8, 1.9 ± 0.3 and 0.8 ± 0.1/100,000/year, respectively. During 2004–2011, the incidence of surgery increased in total (p = .044), especially in age groups 70–79 years and ≥80 years (p = .012 and p = .031). After surgery, 253 of 652 iNPH patients (38.8%) improved at least one step on the modified Rankin scale (mRS). Number needed to treat was 3.0 for improving one patient from unfavourable (mRS 3–5) to favourable (mRS 0–2). The mean score of a modified iNPH scale increased from 54 ± 23 preoperatively to 63 ± 25 postoperatively (p < .0001, n = 704), and 58% improved. No significant regional differences in incidence, surgical techniques or outcome were found.Conclusions: Incidence of hydrocephalus surgery increased significantly during 2004–2011, specifically in elderly patients. Surgical treatment of iNPH markedly improved functional independence, but the improvement rate was low compared to recent single- and multicentre studies. Thus, the potential for surgical improvement is likely lower than generally reported when treating patients as part of everyday clinical care.