A prospective study on gait dominant normal pressure hydrocephalus

Eye movement abnormalities in normal pressure hydrocephalus: a video-oculographic study

BACKGROUND

Eye movement dysfunction has been widely observed in several neurodegenerative diseases. Normal pressure hydrocephalus (NPH) is a treatable condition showing marked clinical and radiological overlap with neurodegenerative parkinsonism and dementia syndromes, often posing diagnostic challenges. The current study employed video-oculography (VOG) aiming to comprehensively explore possible ocular dysfunction in NPH patients.

METHODS

Forty-two consecutive NPH patients and seventy-six healthy controls (HC) were enrolled in the study. Participants underwent a video-oculographic assessment including reflexive saccades and fixation tasks. Amplitude, peak velocity and latency of upward, downward, and vertical saccades were calculated, together with square wave jerks (SWJ) number and amplitude during fixation. Correlations between VOG data and clinico-radiological features were investigated.

RESULTS

NPH patients showed a significant (33.8%) increase in saccadic latency compared to HC, with no differences in saccadic amplitude and peak velocity. The number and amplitude of SWJ were also similar between NPH and HC groups. Saccadic latency was specifically associated with cognitive deficits, especially phonemic fluency and executive functions, in the NPH group.

CONCLUSION

This study characterized ocular dysfunction in NPH patients, demonstrating an increase of saccadic latency in comparison with HC, strongly associated with cognitive impairment. These results identified saccadic latency as a rapid and quantitative VOG biomarker of cognitive deficits in NPH, holding potential for repeated assessment of cognitive status over time. On the other hand, saccadic amplitude and velocity were not affected in NPH, thus suggesting their possible role in the differential diagnosis between NPH and neurodegenerative parkinsonian syndromes.

Physical activity and gait in patients with idiopathic normal pressure hydrocephalus: a literature review

Background

Idiopathic normal pressure hydrocephalus (iNPH) is characterized by impaired gait and cognition, and urinary incontinence. Even though iNPH still lacks standardized diagnostic criteria, many patients may potentially benefit from treatment which are often invasive procedures.

Objectives

To provide an overview of the current state of research on physical activity behavior and gait in patients with iNPH, and examine potential changes after treatment (i.e., shunt surgery, spinal tap test or lumbar drainage).

Methods

This literature review was carried out based on the PRISMA statement and we searched PubMed, Web of Science and Scopus databases in April 2023.

Results

In total, 32 studies were included: 29 focusing on gait, 2 focusing on gait and physical activity, and 1 focusing on physical activity. All studies reported improvements in gait, such as reduced gait ataxia or shuffling gait and greater variability of gait cycle length, after an intervention or treatment. Improvements may depend on patients' age, symptom duration, and treatment method, among others.

Conclusion

Improvements in gait after iNPH treatment (e.g., shunt surgery) are well documented, whereas results on physical activity behavior in iNPH patients are inconsistent. More research on physical activity and gait outcomes before and after treatment is needed, also with regard to treatment success.

Validation of Parental Reports in Assessing Idiopathic Toe Walking Using Quantitative In-Shoe Device Measurements

BACKGROUND

Toe walking is prevalent among children, affecting 5% to 24% of the pediatric population. Clinicians rely on parental reports of frequency of toe walking to guide clinical decision making and outcomes assessment. However, recall accuracy and differing environments challenge the reliability of parental reports. This study aims to validate parental reports against quantitative in-shoe device measurements (NURVV/RUN).

METHODS

Twenty children with persistent idiopathic toe walking (ITWp) (mean age: 9.6y; 13 males, 7 females) from 8 pediatric orthopaedic specialty care sites participated in this multicenter study. Parents assessed toe walking frequency using a 6-point scale, while children wore NURVV/RUN insoles for 8 hours/day over 7 days. Insole sensors recorded foot strike patterns (rearfoot, midfoot, and forefoot), which were classified using the same severity scale. Agreement between parental reports and NURVV data was assessed using weighted Kappa statistics (P<0.05).

RESULTS

Before intervention, children with ITWp exhibited daily walking patterns: 61.7% forefoot, 15.3% midfoot, and 22.8% hindfoot contact. Agreement analysis showed substantial agreement (k=0.688, P<0.001) for combined forefoot and midfoot contacts and fair agreement (k=0.381, P<0.005) for isolated forefoot contact.

CONCLUSION

Parental reports of toe walking prevalence in their children are relatively accurate, supporting their use in clinical management. However, quantitative in-shoe devices provide a more objective and quantitative understanding of ITWp frequency and have the potential to guide clinical decision-making and outcomes assessment children with ITWp.

LEVEL OF EVIDENCE

Level II-diagnostic study. See instructions to authors for a complete description of levels of evidence.

Standardizing the large-volume "tap test" for evaluating idiopathic normal pressure hydrocephalus: a systematic review

INTRODUCTION

Idiopathic normal pressure hydrocephalus (iNPH) is characterized by the clinical triad of gait, cognitive, and urinary dysfunction associated with ventriculomegaly on neuroimaging. Clinical evaluation before and after CSF removal via large volume lumbar puncture (the "tap test") is used to determine a patient's potential to benefit from shunt placement. Although clinical guidelines for iNPH exist, a standardized protocol detailing the procedural methodology of the tap test is lacking.

EVIDENCE ACQUISITION

Using PRISMA guidelines, a systematic review of PubMed and Embase identifying studies of the tap test in iNPH was performed, centered on four clinical questions (volume of CSF to remove, type of needle for lumbar puncture, which clinical assessments to utilize, and timing of assessments). A modified Delphi approach was then applied to develop a consensus standardized tap test protocol for the evaluation of idiopathic normal pressure hydrocephalus.

EVIDENCE SYNTHESIS

Two hundred twenty-two full-text articles encompassing a total of 80,322 participants with iNPH met eligibility and were reviewed. Variations in the tap test protocol resulted in minimal concordance among studies. A standardized protocol of the tap test was iteratively developed over a two-year period by members of the International Parkinson and Movement Disorders Society Normal Pressure Hydrocephalus Study Group until expert consensus was reached.

CONCLUSIONS

The literature shows significant variability in the procedural methodology of the tap test. The proposed protocol was subsequently developed to standardize clinical management, improve patient outcomes, and better align future research in idiopathic normal pressure hydrocephalus.

Technological Advances for Gait and Balance in Normal Pressure Hydrocephalus: A Systematic Review

Normal pressure hydrocephalus (NPH) is a recognized cause of reversible cognitive and motor decline, with gait and balance impairments often emerging early. Technologies providing gait and balance measures can aid in early detection, diagnosis, and prognosis of the disease. This systematic review comprehensively discusses previous studies on the instrumental assessment of gait and balance in NPH. A PubMed search following PRISMA guidelines identified studies published between 2000 and 2024 that used laboratory instruments to assess gait and balance in NPH. Studies underwent quality assessment for internal, statistical, and external validity. Methodological details such as motor tasks, instruments, analytical approaches, and main findings were summarized. Overall, this review includes 41 studies on gait and 17 on balance, most of which used observational, cross-sectional designs. These studies employed various tools, such as pressure-sensitive platforms, optoelectronic motion-capture systems, and wearable inertial sensors. Significant differences in kinematic measures of gait and balance have been found in NPH patients compared to healthy controls and individuals with other neurological conditions. Finally, this review explores potential pathophysiological mechanisms underlying the kinematic changes in gait and balance in NPH and emphasizes the absence of longitudinal data, which hinders drawing definitive conclusions for prognostic purposes.

Gait characteristics in idiopathic normal pressure hydrocephalus: a review on the effects of CSF tap test and shunt surgery

BACKGROUND

Idiopathic normal pressure hydrocephalus (iNPH) is a progressive disease characterized by disproportionate ventricular enlargement at brain imaging with gait disturbance and an increased risk of falling. Gait assessment is a key feature in the diagnosis of iNPH and characterization of post-surgical outcomes.

RESEARCH QUESTION

How do gait parameters change 24 h after CSF tap test (CSFTT) and after ventriculoperitoneal shunt surgery?

METHODS

The PRISMA guidelines were used to perform the systematic review. We conducted a search of the following electronic databases: PubMed, Medline, Web of Science and EBSCO. We included studies focusing on gait changes occurring 24 h after a CSFTT or after ventriculoperitoneal shunt surgery in patients with iNPH. All articles were assessed for methodological quality using an adapted version of The Standard Quality Assessment Criteria for Evaluating Primary Research Papers checklist.

RESULTS

Twenty-seven studies were included in the systematic review. Studies were highly heterogeneous due to lack of standardization of CSFTT or shunt surgery methodology, with varying amounts of CSF removed during the tap test (20-50 ml) and varying time of outcome assessment after shunt surgery. Dynamic equilibrium measurements are generally used to assess preoperative levels of cardinal symptoms and postoperative outcomes in iNPH. The most sensitive spatio-temporal parameter assessed 24 h after CSFTT was self-selected walking speed followed by stride length, which increased significantly. Cadence is hence not suitable to consider in the evaluation of effect of CSFTT and shunt surgery. Changes in balance-related gait parameters after CSFTT and shunt surgery are still a controversial area of research.

CONCLUSION

Gait assessment is a key feature in the diagnosis of iNPH and characterization of post-surgical outcomes. Dynamic equilibrium measurements are generally used to assess preoperative levels of cardinal symptoms and postoperative outcomes in iNPH, but quantitative and standardized gait analysis procedures are missing. Changes in balance-related gait parameters after CSFTT might be useful in deciding whether to perform shunt surgery in iNPH patients who hope for improvement in gait ability. The dual-task paradigm after CSFTT could improve the clinical evaluation of higher level frontal gait disturbances in patients with suspected iNPH before shunting.

Reliability of an Instrumented Pressure Walkway for Measuring Walking and Running Characteristics in Young, Athletic Individuals

Background

Spatiotemporal parameters of gait are useful for identifying pathological gait patterns and presence of impairments. Reliability of the pressure-sensitive ZenoTM Walkway has not been established in young, active individuals without impairments, and no studies to this point have included running.

Purpose

The purposes of this study were to 1) determine if up to two additional trials of walking and running on the ZenoTM Walkway are needed to produce consistent measurements of spatiotemporal variables, and 2) establish test-retest reliability and minimal detectable change (MDC) values for common spatiotemporal variables measured during walking and running.

Study Design

Cross-Sectional Laboratory Study.

Methods

Individuals (n=38) in this cross-sectional study walked and ran at self-selected comfortable speed on a pressure-sensitive ZenoTM Walkway. Twenty-one participants returned for follow-up testing between one and 14 days later. Intraclass correlation coefficients (ICCs) were used to assess reliability of spatiotemporal variable means using three, four, or five passes over the ZenoTM Walkway and to assess test-retest reliability of spatiotemporal variables across sessions.

Results

All variables showed excellent reliability (ICC > 0.995) for walking and running when measured using three, four, or five passes. Additionally, all variables demonstrated moderate to excellent test-retest reliability during walking (ICC: 0.732-0.982) and running (ICC: 0.679-0.985).

Conclusion

This study establishes a reliable measurement protocol of three one-way passes when using the ZenoTM Walkway for walking or running analysis. This is the first study to establish reliability of the ZenoTM Walkway during running and in young, active individuals without neuromusculoskeletal pathology.

Level of Evidence

3b.

Gait Analysis in Idiopathic Normal Pressure Hydrocephalus: A Meta-Analysis

Background

Gait analysis objectively quantifies gait impairment in idiopathic normal pressure hydrocephalus (iNPH), may improve diagnosis and evaluation for surgical candidacy.

Objectives

This meta-analysis aims to understand which objective gait parameters improve after tap-test (TT) and CSF shunt surgery (CSS), also comparing responders (R) with non-responders (NR) and to assess if gait restores within the range of healthy controls after procedures.

Methods

Studies enrolling iNPH with at least one instrumented gait measure were selected. Three time points of gait assessment were defined: PRE, POST-TT, and POST-CSS. Gait velocity, cadence, step length, stride length, and double limb support time were evaluated. Patients were categorized based on responsiveness to CSF diversion procedures.

Results

Seventeen studies including 527 patients were selected. iNPH improved significantly in almost all gait parameters POST-TT, and to a greater extent POST-CSS. Gait parameters consistently discriminated iNPH from healthy controls. Despite the aforementioned improvements, iNPH's gait did not completely normalize after CSF diversion procedures. Meta-regression analysis also revealed that TT's effect on gait velocity plateaus after 24-48 hr and returns to baseline in 90-100 hr.

Conclusions

Gait analysis is a reliable quantitative instrument to assess gait impairment in iNPH, demarking a net differentiation from healthy controls, according to the notion that the iNPH CSF dynamic alteration also leads to an irreversible damage. Specific gait parameters improve among TT-R, providing an opportunity to select patients that will respond to CSS. Future studies validating a standardized reporting method including criteria of responsiveness, specific gait parameters, and timeframe of assessment are needed.

Quantitative Evaluation of Gait Changes Using APDM Inertial Sensors After the External Lumbar Drain in Patients With Idiopathic Normal Pressure Hydrocephalus

Objectives: Gait and balance disturbances are common symptoms of idiopathic normal pressure hydrocephalus (iNPH). This study aimed to quantitatively evaluate gait and balance parameters after external lumbar drainage (ELD) using APDM inertial sensors.

Methods: Two-minute walkway tests were performed in 36 patients with suspected iNPH and 20 healthy controls. A total of 36 patients underwent ELD. According to clinical outcomes, 20 patients were defined as responders, and the other 16 as non-responders. The gait parameters were documented, and the corresponding differences between responders and non-responders were calculated.

Results: When compared with healthy controls, patients with suspected iNPH exhibited decreased cadence, reduced gait speed, a higher percentage of double support, decreased elevation at mid-swing, reduced foot strike angle, shorter stride length, difficulty in turning, and impaired balance functions. After the ELD, all these manifestations, except elevation at mid-swing and balance functions, were significantly improved in responders. The change of Z-score absolute value in the six parameters, except for foot strike angle, was >1. No significant improvement was observed in non-responders.

Conclusion: APDM inertial sensors are useful for the quantitative assessment of gait impairment in patients with iNPH, which may be a valuable tool for identifying candidates that are suitable for shunting operations.