Interest of dual-task-related gait changes in idiopathic normal pressure hydrocephalus

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.

Quantification of pathological gait parameter thresholds of idiopathic normal pressure hydrocephalus patients in clinical gait analysis

The aim of the study was to distinguish the hypokinetic gait disorder in idiopathic normal pressure hydrocephalus (NPH) patients from the gait decline in the elderly population by quantifying pathological gait parameter thresholds utilizing a multiple condition gait assessment. 55 NPH patients and 55 age-matched healthy subjects underwent a standardized gait assessment with eight gait conditions. Spatiotemporal gait parameters were assessed through a pressure-sensitive carpet. Statistical analysis consisted of a binary logistic regression (BLR) model, logistic curve-fit evaluated by a Chi-square goodness-of-fit-test, receiver operating characteristic models with area under the curves (AUC), and inverse BLR. Most discriminative gait parameter thresholds were observed in pace, gait cycle, and support gait domains. The most distinct gait conditions were preferred walking speed and semantic dual task. During preferred walking speed, the most significant gait parameter thresholds were stride length ≤ 1.02 m (sensitivity 0.93/specificity 0.91/AUC 0.96), gait velocity ≤ 0.83 m/s (0.80/0.91/0.93), double support phase ≥ 27.0% (0.96/0.76/0.91), and stride length coefficient of variation ≥ 3.4% (0.93/0.72/0.90). In conclusion, the hypokinetic gait disorder in NPH can be quantitatively differentiated from gait patterns of the elderly population. In future studies, this approach may be useful to differentiate clinical entities with similar gait disorders utilizing instrumented gait analysis procedures.

Dual-Task Performance in Older Adults With and Without Idiopathic Normal Pressure Hydrocephalus

Two of the main features of idiopathic normal pressure hydrocephalus (iNPH) are disturbed gait and cognition. These features are typically investigated separately, but here we combined walking with a cognitive task to investigate if older adults with iNPH were more susceptible to dual-task interference on walking than those without iNPH. In total, 95 individuals from the general population participated in our study. Of these, 20 were classified as Possible iNPH (median [interquartile range, IQR] 80 years [75–82.5]) and 75 as Unlikely iNPH (74 years [72–78]). Conversation, 10-m walking, semantic and phonemic verbal fluency were performed either combined or independently. “Stopping walking while talking” was noted. Pairwise comparisons and multiple logistic regression analyses were used. We found that the Possible iNPH group was older, stopped walking more frequently during the conversation, and had a slower single-task pace. The dual-task pace was slower for both groups. Only single-task walking pace could predict Possible iNPH when adjusted for age. We could establish a dual-task cost on gait performance in this sample of older adults from the general population, but the cost was not exclusive for individuals with Possible iNPH. To further assess the value of dual-task testing in iNPH, including observations of stopping walking while talking, a study of a clinical iNPH material with more severe symptoms would be valuable.

Dynamic functional networks in idiopathic normal pressure hydrocephalus: Alterations and reversibility by CSF tap test

Idiopathic Normal Pressure Hydrocephalus (iNPH)—the leading cause of reversible dementia in aging—is characterized by ventriculomegaly and gait, cognitive and urinary impairments. Despite its high prevalence estimated at 6% among the elderlies, iNPH remains underdiagnosed and undertreated due to the lack of iNPH‐specific diagnostic markers and limited understanding of pathophysiological mechanisms. INPH diagnosis is also complicated by the frequent occurrence of comorbidities, the most common one being Alzheimer's disease (AD). Here we investigate the resting‐state functional magnetic resonance imaging dynamics of 26 iNPH patients before and after a CSF tap test, and of 48 normal older adults. Alzheimer's pathology was evaluated by CSF biomarkers. We show that the interactions between the default mode, and the executive‐control, salience and attention networks are impaired in iNPH, explain gait and executive disturbances in patients, and are not driven by AD‐pathology. In particular, AD molecular biomarkers are associated with functional changes distinct from iNPH functional alterations. Finally, we demonstrate a partial normalization of brain dynamics 24 hr after a CSF tap test, indicating functional plasticity mechanisms. We conclude that functional changes involving the default mode cross‐network interactions reflect iNPH pathophysiological mechanisms and track treatment response, possibly contributing to iNPH differential diagnosis and better clinical management.

Key gait findings for diagnosing three syndromic categories of dynamic instability in patients with balance disorders

With the emergence of affordable, clinical-orientated gait analysis techniques, clinicians may benefit from a general understanding of quantitative gait analysis procedures and their clinical applications. This article provides an overview of the potential of a quantitative gait analysis for decision support in three clinically relevant scenarios of early stage gait disorders: scenario I: gait ataxia and unsteadiness; scenario II: hypokinesia and slow gait; scenario III: apparently normal gait with a specific fall tendency in complex mobility situations. In a first part, we justify the advantages of standardized data collection and analysis procedures including data normalization and dimensionality reduction techniques that facilitate clinical interpretability of instrument-based gait profiles. We then outline typical patterns of pathological gait and their modulation during different walking conditions (variation of speed, sensory perturbation, and dual tasking) and highlight key aspects that are particularly helpful to support and guide clinical decision-making.

The effects of cerebrospinal fluid tap-test on idiopathic normal pressure hydrocephalus: an inertial sensors based assessment

Background

Gait disturbances are typical of persons with idiopathic normal pressure hydrocephalus (iNPH) without signs distinctive from other neurodegenerative and vascular conditions. Cerebrospinal fluid tap-test (CSF-TT) is expected to improve the motor performance of iNPH patients and is a prognostic indicator in their surgical management. This observational prospective study aims to determine which spatio-temporal gait parameter(s), measured during instrumented motor tests, and clinical scale(s) may provide a relevant contribution in the evaluation of motor performance pre vs. post CSF-TT on iNPH patients with and without important vascular encephalopathy.

Methods

Seventy-six patients (20 with an associated vascular encephalopathy) were assessed before, and 24 and 72 h after the CSF-TT by a timed up and go test (TUG) and an 18 m walking test (18 mW) instrumented using inertial sensors. Tinetti Gait, Tinetti Balance, Gait Status Scale, and Grading Scale were fulfilled before and 72 h after the CSF-TT. Stride length, cadence and total time were selected as the outcome measures. Statistical models with mixed effects were implemented to determine the relevant contribution to response variables of each quantitative gait parameter and clinical scales.

Results and conclusion

From baseline to 72 h post CSF-TT patients improved significantly by increasing cadence in 18 mW and TUG (on average of 1.7 and 2.4 strides/min respectively) and stride length in 18 mW (on average of 3.1 cm). A significant reduction of gait apraxia was reflected by modifications in double support duration and in coordination index.

Tinetti Gait, Tinetti Balance and Gait Status Scale were able to explain part of the variability of response variables not covered by instrumental data, especially in TUG. Grading Scale revealed the highest affinity with TUG total time and cadence when considering clinical scales alone.

Patients with iNPH and an associated vascular encephalopathy showed worst performances compared to pure iNPH but without statistical significance. Gait improvement following CSF-TT was comparable in the two groups. Overall these results suggest that, in order to augment CSF-TT accuracy, is key to assess the gait pattern by analyzing the main spatio-temporal parameters and set post evaluation at 72 h.

Trial registration

Approved by ethics committee: CE 14131 23/02/2015.

Minor gait impairment despite white matter damage in pure small vessel disease

OBJECTIVE

Gait impairment is common in patients with cerebral small vessel disease (SVD). However, gait studies in elderly SVD patients might be confounded by age-related comorbidities, such as polyneuropathy or sarcopenia. We therefore studied young patients with the genetically defined SVD CADASIL. Our aim was to examine the effects of pure SVD on single and dual task gait, and to investigate associations of gait performance with cognitive deficits and white matter alterations.

METHODS

We investigated single task walking and calculatory, semantic, or motoric dual task costs in 39 CADASIL patients (mean age 50 ± 8) using a computerized walkway. We obtained 3.0T MRI and neuropsychological data on processing speed, the main cognitive deficit in CADASIL. Spatiotemporal gait parameters were standardized based on data from 192 healthy controls. Associations between white matter integrity, assessed by diffusion tensor imaging, and gait were analyzed using both a global marker and voxel-wise analysis.

RESULTS

Compared to controls, CADASIL patients showed only mild single task gait impairment, and only in the rhythm domain. The semantic dual task additionally uncovered mild deficits in the pace domain. Processing speed was not associated with gait. White matter alterations were related to single task stride length but not to dual task performance.

INTERPRETATION

Despite severe disease burden, gait performance in patients with pure small vessel disease was relatively preserved in single and dual tasks. Results suggest that age-related pathologies other than small vessel disease might play a role for gait impairment in elderly SVD patients.

Subjective Memory Impairment and Gait Variability in Cognitively Healthy Individuals: Results from a Cross-Sectional Pilot Study

BACKGROUND

Increased stride time variability has been associated with memory impairment in mild cognitive impairment. Subjective memory impairment (SMI) is considered the earliest clinical stage of Alzheimer's disease (AD). The association between increased stride time variability and SMI has not been reported.

OBJECTIVE

This study aims to examine the association of stride time variability while performing single and dual tasking with SMI in cognitively healthy individuals (CHI).

METHODS

A total of 126 CHI (15 without SMI, 69 with SMI expressed by participants, 10 with SMI expressed by participant's relative, and 32 with SMI expressed by both participants and their relatives) were included in this cross-sectional study. The coefficient of variation (CoV) of stride time and walking speed were recorded under usual condition and while counting backwards. Age, gender, body mass index, number of drugs taken daily, use of psychoactive drugs, fear of falling, history of previous falls, and walking speed were used as covariates.

RESULTS

The multiple linear regression models showed that greater CoV of stride time while counting backwards, but not while single tasking, was associated with a participant's relative SMI (p = 0.038).

CONCLUSION

This study found a specific association between SMI expressed by a participant's relative and a greater CoV of stride time (i.e., worse performance) while dual tasking, suggesting that the association between gait variability and memory may be present in the earliest stages of memory impairment. Thus, gait variability under dual-task in individuals with SMI expressed by their relatives can be a potential biomarker of AD.

Brain comorbidities in normal pressure hydrocephalus

BACKGROUND AND PURPOSE

This cross-sectional study aims to compare gait changes after the cerebrospinal fluid (CSF) tap test between normal pressure hydrocephalus patients with and without brain comorbidities (NPH+ and NPH- respectively) and then to identify significant contributors to a poor CSF tap test amongst individuals with NPH+.

METHODS

Gait changes (during the single task and the dual task of backward counting) were quantified before and 24 h after the CSF tap test with an optoelectronic system in 52 NPH patients (77.4 ± 6.0 years; 34.6% women). Changes after the CSF tap test in stride time variability (STV, %) were our main outcome. CSF Alzheimer's disease biomarkers, cerebrovascular white matter changes assessed with brain imaging and neurodegenerative diseases with parkinsonian syndrome represented the three individual brain comorbidities.

RESULTS

Brain comorbidities were frequently identified, NPH+ patients representing 40 patients of our sample (76.9%). NPH- patients improved their STV better in the single task (delta of STV = -58.6% ± 54.3% vs. -14.1% ± 62.0%; P = 0.031) and in the dual task (delta of STV =-32.2% ± 33.7% vs. 6.3% ± 58.4%; P = 0.028) after the CSF tap test than NPH+ patients. Amongst NPH+ individuals, only comorbid Alzheimer's disease was associated with STV increase (i.e. deterioration of gait) in the dual task [β 38.4; 95% confidence interval (5.64; 71.24); P = 0.023] after the CSF tap test, whilst it was borderline in the single task [β 35.0; 95% confidence interval (-1.97; 71.90); P = 0.063].

CONCLUSIONS

Brain comorbidities affect gait improvement after the CSF tap test in NPH patients; this influence is driven by Alzheimer's disease-related pathology.

Apathy and higher level of gait control in normal pressure hydrocephalus

Apathy represents the most common behavioral disturbance in patients with suspicion of idiopathic normal pressure hydrocephalus (iNPH) and has a major impact on quality of life. However, its impact on gait -the hallmark motor disturbance of iNPH - has never been studied yet. This study aims to evaluate the impact of apathy on higher level of gait control in patients with suspicion of iNPH. Stride time variability (STV), a marker of higher level of gait control, was quantified during usual walking (single task) and during walking while performing simultaneously cognitive tasks (dual task) of counting and verbal fluency. Among 46 patients with suspicion of iNPH (77.6±6.7years; 34.8% women), 30 (65.2%) presented apathy (defined by a score≥14 on the Starkstein apathy scale). Backward counting induced more important worsening of STV (i.e. increasing STV) in apathetic compared to non-apathetic patients (14.8±25.1% versus 9.0±20.4%; p=0.005), while both groups presented similar executive functioning. These findings suggest that apathy contributes to gait disorders in iNPH. Apathy is easy to monitor and should be considered as a target symptom of treatment.

Walking assessment after lumbar puncture in normal-pressure hydrocephalus: a delayed improvement over 3 days

OBJECTIVE The determination of gait improvement after lumbar puncture (LP) in idiopathic normal-pressure hydrocephalus (iNPH) is crucial, but the best time for such an assessment is unclear. The authors determined the time course of improvement in walking after LP for single-task and dual-task walking in iNPH. METHODS In patients with iNPH, sequential recordings of gait velocity were obtained prior to LP (time point [TP]0), 1-8 hours after LP (TP1), 24 hours after LP (TP2), 48 hours after LP (TP3), and 72 hours after LP (TP4). Gait analysis was performed using a pressure-sensitive carpet (GAITRite) under 4 conditions: walking at preferred velocity (STPS), walking at maximal velocity (STMS), walking while performing serial 7 subtractions (dual-task walking with serial 7 [DTS7]), and walking while performing verbal fluency tasks (dual-task walking with verbal fluency [DTVF]). RESULTS Twenty-four patients with a mean age of 76.1 ± 7.8 years were included in this study. Objective responder status moderately coincided with the self-estimation of the patients with subjective high false-positive results (83%). The extent of improvement was greater for single-task walking than for dual-task walking (p < 0.05). Significant increases in walking speed were found at TP2 for STPS (p = 0.042) and DTVF (p = 0.046) and at TP3 for STPS (p = 0.035), DTS7 (p = 0.042), and DTVF (p = 0.044). Enlargement of the ventricles (Evans Index) positively correlated with early improvement. Gait improvement at TP3 correlated with the shunt response in 18 patients. CONCLUSIONS Quantitative gait assessment in iNPH is important due to the poor self-evaluation of the patients. The maximal increase in gait velocity can be observed 24-48 hours after the LP. This time point is also best to predict the response to shunting. For dual-task paradigms, maximal improvement appears to occur later (48 to 72 hours). Assessment of gait should be performed at Day 2 or 3 after LP.

Improvement in executive subfunctions following cerebrospinal fluid tap test identifies idiopathic normal pressure hydrocephalus from its mimics

BACKGROUND AND PURPOSE

Patients with idiopathic normal pressure hydrocephalus (iNPH) present cognitive deficits that overlap with other neurological conditions such as Parkinson's disease or vascular dementia, therefore mimicking iNPH. This prospective study aimed to compare cognitive performances between iNPH and iNPH mimics before and after cerebrospinal fluid (CSF) tapping.

METHODS

A total of 57 patients with suspicion of iNPH (75.84 ± 6.42 years; 39% female) were included in this study (37 iNPH and 20 iNPH mimics). Neuropsychological assessments were performed before and 24 h after CSF tapping of 40 ml. Multivariate logistic regressions were used to examine the association between iNPH and cognitive functions, adjusted for age, education, baseline cognitive assessment and disease duration.

RESULTS

Both groups presented the same baseline cognitive performances. After CSF tapping, iNPH patients improved their semantic (P = 0.001) and phonemic verbal fluencies (P = 0.001), whereas iNPH mimics presented similar performances to before CSF tapping. The phonemic verbal fluency (odds ratio 1.43, 95% confidence interval 1.05; 1.96) and the Color Trails Test (odds ratio 0.10, 95% confidence interval 0.01; 0.76) improvements were the two discriminative cognitive tests that identified iNPH from iNPH mimics.

CONCLUSION

Improvement in executive subfunctions after CSF tapping identified iNPH patients from other neurological conditions that mimic iNPH. These findings respond to clinical issues encountered on a daily basis and would improve the diagnostic process of iNPH.

Dual-task training on a treadmill to improve gait and cognitive function in elderly idiopathic fallers

BACKGROUND AND PURPOSE

Daily activities require the ability to dual task (DT), utilizing cognitive resources while walking to negotiate complex environmental conditions. For older adults, these additional cognitive demands often lead to reduced gait quality that increases the risk of falls. The aim of this study was to assess whether a combined intervention, consisting of treadmill training (TT) while performing DT, improves cognitive and motor performance in older adults with a history of multiple falls.

METHODS

A repeated measures design was used to evaluate the effects of training in 10 elderly fallers (mean age, 78.1 ± 5.81 y, 7 women). The progressive intensive training sessions included walking on a treadmill while practicing a variety of dual tasks 3 times a week for more than 6 weeks. Cognitive and motor measures were used to assess the effects of the intervention immediately after training and 1 month posttraining.

RESULTS

Improvements were observed in Berg Balance Scale (P = 0.02), Dynamic Gait Index (P = 0.03), gait speed during usual walking and while DT (P < 0.05), and cognitive performance as measured by the Trails Making Test B (P = 0.02). Furthermore, quality of life improved (SF-36: P = 0.01) as did physical activity (Physical Activity Scale for Elderly: P = 0.02). At 1 month postintervention, changes were not significant.

DISCUSSION AND CONCLUSIONS

After 6 weeks of TT + DT program, elderly fallers demonstrated improved scores on tests of mobility, functional performance tasks, and cognition.Dual task training can be readily implemented by therapists as a component of a fall-risk reduction training program.Video Abstract available. See Video (Supplemental Digital Content 1, http://links.lww.com/JNPT/A81) for more insights from the authors.

Dopaminergic denervation is not necessary to induce gait disorders in atypical parkinsonian syndrome

BACKGROUND

Gait impairment is common in parkinsonian syndromes but not specific to striatonigral dysfunction. The relationship between the dopaminergic system and gait parameters is poorly understood. This cross-sectional study aimed to determine if gait measures are related to the striatal dopamine transporters distribution using [(123)I]FP-CIT SPECT in patients with parkinsonian syndromes.

MATERIALS AND METHODS

Twenty-four patients with gait impairment and parkinsonian syndromes without Parkinson's disease (mean age: 73.6±8.2years) were included in this study. Gait analysis during single- and dual-task condition (walking and backwards counting) and [(123)I]FP-CIT SPECT were performed within 3months of each other. Patients were visually categorized as having normal (n=14) or abnormal (n=10) [(123)I]FP-CIT SPECT. In addition, a volume-of-interest-based analysis of uptake ratios (caudate and putamen) relative to the occipital cortex and a voxelwise analysis using SPM8 were also performed.

RESULTS

Patients with parkinsonian syndromes and abnormal [(123)I]FP-CIT SPECT did not significantly differ in terms of spatiotemporal gait parameters from those with normal [(123)I]FP-CIT SPECT. Moreover, after correction for multiple comparisons, we did not observe any association between regional uptake ratio and spatiotemporal gait parameters for single and dual tasking. Finally, none of these parameters showed a significant association with voxelwise [(123)I]FP-CIT uptake.

CONCLUSIONS

Dopaminergic denervation, as measured by [(123)I]FP-CIT SPECT, is not necessary to induce alterations of spatiotemporal gait parameters during single and dual task in patients presenting with atypical parkinsonian syndromes.

Dual-task related gait changes after CSF tapping: a new way to identify idiopathic normal pressure hydrocephalus

Background

Gait disturbances found in patients with idiopathic normal pressure hydrocephalus (iNPH) are unspecific to the diagnosis and commonly occur in neurodegenerative or vascular conditions (iNPH-like conditions). This current retrospective pre-post intervention study aims to determine whether changes in quantitative gait parameters during dual task condition differed between iNPH and iNPH-like conditions before and after cerebrospinal fluid (CSF) tapping.

Methods

49 patients assessed before and after CSF tapping were included in this study (27 with iNPH and 22 with iNPH-like conditions). Gait analysis during single and dual task conditions (walking and backward counting) was performed before and after a CSF spinal tap of 40 ml. Gait parameters were compared between iNPH and iNPH-like conditions patients. Logistic regressions were used to examine the association between iNPH and gait parameters.

Results

Improvements of step width (−9.03 (20.75)% for iNPH group; +0.28 (21.76)% for iNPH-like conditions group), stride length (+7.82 (20.71)% for iNPH group; -0.62 (19.22)% for iNPH-like conditions group), walking speed (+12.20 (29.79)% for iNPH group; +2.38 (32.50)% for iNPH-like conditions group) and stance duration (−1.23 (4.03)% for iNPH group; +0.49 (5.12)% for iNPH-like conditions group) during dual task, after CSF spinal tapping, were significant in patients with iNPH compared to patients with iNPH-like conditions. No between group difference was observed for the single walking task evaluation. The multiple logistic regression revealed that among these four gait parameters, only the improvement in step width was associated with the diagnosis of iNPH.

Conclusion

Dual-task related changes in spatio-temporal gait parameters before and after CSF tapping might be a novel and discriminative method of identifying iNPH patients from other similar conditions.

Strategic targeted exercise for preventing falls in elderly people

OBJECTIVE

Randomized, controlled, blinded trial to evaluate the effectiveness of strategic targeted exercise for preventing falls in elderly people.

METHODS

Elderly people were randomly allocated to either a control group that received conventional exercise, or a training group that received conventional exercise plus proprioception and cognitive exercises. Subjects were asked to exercise three times a week (40 min per session) for 8 weeks. In the pre- and post-training sessions, all participants were assessed using a static postural control test with eyes open and closed, the Berg Balance Scale (BBS) and the joint position sense test of the lower limbs.

RESULTS

After 8 weeks, there were statistically significant improvements in the training group (n = 50) compared with the control group (n = 50) for mediolateral sway distance with eyes open and eyes closed, anteroposterior sway distance with eyes open but not with eyes closed, BBS scores and joint position sense test for the left but not the right knee.

CONCLUSION

This study demonstrated that strategic targeted exercise could produce more beneficial effects on balance and proprioception function than conventional exercise alone, in elderly people.