Interference of rhythmic constraint on gait in healthy subjects and patients with early Parkinson's disease: evidence for impaired locomotor pattern generation in early Parkinson's disease

An integrated review of music cognition and rhythmic stimuli in sensorimotor neurocognition and neurorehabilitation

This work reviews the growing body of interdisciplinary research on music cognition, using biomechanical, kinesiological, clinical, psychosocial, and sociological methods. The review primarily examines the relationship between temporal elements in music and motor responses under varying contexts, with considerable relevance for clinical rehabilitation. After providing an overview of the terminology and approaches pertinent to theories of rhythm and meter from the musical-theoretical and cognitive fields, this review focuses on studies on the effects of rhythmic sensory stimulation on gait, rhythmic cues' effect on the motor system, reactions to rhythmic stimuli attempting to synchronize mobility (i.e., musical embodiment), and the application of rhythm for motor rehabilitation for individuals with Parkinson's disease, stroke, mild cognitive impairment, Alzheimer's disease, and other neurodegenerative or neurotraumatic diseases. This work ultimately bridges the gap between the musical-theoretical and cognitive science fields to facilitate innovative research in which each discipline informs the other.

The effect of auditory cues on gait variability in people with Parkinson's disease and older adults: a systematic review

Aim: The goal of this study was to analyze the effects of external rhythmic auditory stimulation (RAS) on gait variability in older adults and people with Parkinson's disease (PD). Methods: Academic databases searched included PubMed, Web of Science, PEDro and Cochrane, from inception to September 2021. Eligible articles scored a minimum of 4 on the PEDro scale. Results: Twenty-three papers were included. People with PD show varied responses in gait variability to RAS during cued walking trials. Healthy older adults tended to increase variability during cued trials. Cue rates below preferred walking cadence tend to increase gait variability. Conclusion: Gait variability is closely associated with fall risk and an important consideration in development of gait rehabilitation techniques.

Robot-assisted gait training in patients with Parkinson's disease: Implications for clinical practice. A systematic review

BACKGROUND

Gait impairments are common disabling symptoms of Parkinson's disease (PD). Among the approaches for gait rehabilitation, interest in robotic devices has grown in recent years. However, the effectiveness compared to other interventions, the optimum amount of training, the type of device, and which patients might benefit most remains unclear.

OBJECTIVE

To conduct a systematic review about the effects on gait of robot-assisted gait training (RAGT) in PD patients and to provide advice for clinical practice.

METHODS

A search was performed on PubMed, Scopus, PEDro, Cochrane library, Web of science, and guideline databases, following PRISMA guidelines. We included English articles if they used a robotic system with details about the intervention, the parameters, and the outcome measures. We evaluated the level and quality of evidence.

RESULTS

We included twenty papers out of 230 results: two systematic reviews, 9 randomized controlled trials, 4 uncontrolled studies, and 5 descriptive reports. Nine studies used an exoskeleton device and the remainders end-effector robots, with large variability in terms of subjects' disease-related disability.

CONCLUSIONS

RAGT showed benefits on gait and no adverse events were recorded. However, it does not seem superior to other interventions, except in patients with more severe symptoms and advanced disease.

Mechanomyography and acceleration show interlimb asymmetries in Parkinson patients without tremor compared to controls during a unilateral motor task

The mechanical muscular oscillations are rarely the objective of investigations regarding the identification of a biomarker for Parkinson's disease (PD). Therefore, the aim of this study was to investigate whether or not this specific motor output differs between PD patients and controls. The novelty is that patients without tremor are investigated performing a unilateral isometric motor task. The force of armflexors and the forearm acceleration (ACC) were recorded as well as the mechanomyography of the biceps brachii (MMGbi), brachioradialis (MMGbra) and pectoralis major (MMGpect) muscles using a piezoelectric-sensor-based system during a unilateral motor task at 70% of the MVIC. The frequency, a power-frequency-ratio, the amplitude variation, the slope of amplitudes and their interlimb asymmetries were analysed. The results indicate that the oscillatory behavior of muscular output in PD without tremor deviates from controls in some parameters: Significant differences appeared for the power-frequency-ratio (p = 0.001, r = 0.43) and for the amplitude variation (p = 0.003, r = 0.34) of MMGpect. The interlimb asymmetries differed significantly concerning the power-frequency-ratio of MMGbi (p = 0.013, r = 0.42) and MMGbra (p = 0.048, r = 0.39) as well as regarding the mean frequency (p = 0.004, r = 0.48) and amplitude variation of MMGpect (p = 0.033, r = 0.37). The mean (M) and variation coefficient (CV) of slope of ACC differed significantly (M: p = 0.022, r = 0.33; CV: p = 0.004, r = 0.43). All other parameters showed no significant differences between PD and controls. It remains open, if this altered mechanical muscular output is reproducible and specific for PD.

Rhythmic movement and rhythmic auditory cues enhance anticipatory postural adjustment of gait initiation

The purpose of this study was to determine whether the rhythmic movements or cues enhance the anticipatory postural adjustment (APA) of gait initiation. Healthy humans initiated gait in response to an auditory start cue (third cue). A first auditory cue was given 8 s before the start cue, and a second auditory cue was given 3 s before the start cue. The participants performed the rhythmic medio-lateral weight shift (ML-WS session), rhythmic anterior-posterior weight shift (AP-WS session), or rhythmic arm swing (arm swing session) in the time between the first and second cues. In the rhythmic cues session, rhythmic auditory cues with a frequency of 1 Hz were given in this time. In the stationary session, the participants maintained stationary stance in this time. The APA and initial step movement preceded by those rhythmic movements or cues were compared with those in the stationary session. The temporal characteristics of the initial step movement of the gait initiation were not changed by the rhythmic movements or cues. The medio-lateral displacement of the APA in the ML-WS and arm swing sessions was significantly greater than that in the stationary session. The anterior-posterior displacement of the APA in the rhythmic cues and arm swing sessions was significantly greater than that in the stationary session. Taken together, the rhythmic movements and cues enhance the APA of gait initiation. The present finding may be a clue or motive for the future investigation for using rhythmic movements or cues as the preparatory activity to enlarge the small APA of gait initiation in the patients with Parkinson's disease.

Mental Singing Reduces Gait Variability More Than Music Listening for Healthy Older Adults and People With Parkinson Disease

BACKGROUND AND PURPOSE

Previously, we showed that internal cues (such as singing) produce similar motor benefits as external cues (such as listening to music) for people with Parkinson disease (PD). This study takes that research further by exploring how singing-either aloud or mentally-at different tempos can ameliorate gait, and it offers insight into how internal cueing techniques may enhance motor performance for older adults and people with PD.

METHODS

Sixty participants aged 50 years and older (30 female) were recruited; 30 had PD and 30 were healthy age-matched controls. Participants completed walking trials involving internal and external cueing techniques at 90%, 100%, and 110% of preferred cadence. The effects of different cue types and rates were assessed in a repeated-measures cross-sectional study by comparing gait characteristics (velocity, cadence, stride length) and variabilities (coefficients of variation of stride length, stride time, single support time).

RESULTS

All participants modified their cadence and stride length during cued conditions, resulting in changes in gait velocity closely reflecting expected changes based upon cue rate. External cues resulted in increased gait variability, whereas internal cues decreased gait variability relative to uncued walking. Variability decreases were more substantial during mental singing at tempos at or above preferred cadence.

DISCUSSION AND CONCLUSIONS

Matching movement to one's own voice improves gait characteristics while reducing gait variability for older adults and people with PD. Optimizing the use of internal cues to facilitate movement is an important step toward more effectively meeting the needs of people with gait disorders related to aging or neurological disease.Video Abstract available for more insights from authors (see Video, Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A286).

Parkinson patients without tremor show changed patterns of mechanical muscle oscillations during a specific bilateral motor task compared to controls

The pathophysiology of Parkinson's disease (PD) is still not understood. There are investigations which show a changed oscillatory behaviour of brain circuits or changes in variability of, e.g., gait parameters in PD. The aim of this study was to investigate whether or not the motor output differs between PD patients and healthy controls. Thereby, patients without tremor are investigated in the medication off state performing a special bilateral isometric motor task. The force and accelerations (ACC) were recorded as well as the Mechanomyography (MMG) of the biceps brachii, the brachioradialis and of the pectoralis major muscles using piezoelectric-sensors during the bilateral motor task at 60% of the maximal isometric contraction. The frequency, a specific power ratio, the amplitude variation and the slope of amplitudes were analysed. The results indicate that the oscillatory behaviour of motor output in PD patients without tremor deviates from controls: thereby, the 95%-confidence-intervals of power ratio and of amplitude variation of all signals are disjoint between PD and controls and show significant differences in group comparisons (power ratio: p = 0.000-0.004, r = 0.441-0.579; amplitude variation: p = 0.000-0.001, r = 0.37-0.67). The mean frequency shows a significant difference for ACC (p = 0.009, r = 0.43), but not for MMG. It remains open, whether this muscular output reflects changes of brain circuits and whether the results are reproducible and specific for PD.

A Review on the Relationship Between Sound and Movement in Sports and Rehabilitation

The role of auditory information on perceptual-motor processes has gained increased interest in sports and psychology research in recent years. Numerous neurobiological and behavioral studies have demonstrated the close interaction between auditory and motor areas of the brain, and the importance of auditory information for movement execution, control, and learning. In applied research, artificially produced acoustic information and real-time auditory information have been implemented in sports and rehabilitation to improve motor performance in athletes, healthy individuals, and patients affected by neurological or movement disorders. However, this research is scattered both across time and scientific disciplines. The aim of this paper is to provide an overview about the interaction between movement and sound and review the current literature regarding the effect of natural movement sounds, movement sonification, and rhythmic auditory information in sports and motor rehabilitation. The focus here is threefold: firstly, we provide an overview of empirical studies using natural movement sounds and movement sonification in sports. Secondly, we review recent clinical and applied studies using rhythmic auditory information and sonification in rehabilitation, addressing in particular studies on Parkinson's disease and stroke. Thirdly, we summarize current evidence regarding the cognitive mechanisms and neural correlates underlying the processing of auditory information during movement execution and its mental representation. The current state of knowledge here reviewed provides evidence of the feasibility and effectiveness of the application of auditory information to improve movement execution, control, and (re)learning in sports and motor rehabilitation. Findings also corroborate the critical role of auditory information in auditory-motor coupling during motor (re)learning and performance, suggesting that this area of clinical and applied research has a large potential that is yet to be fully explored.

Internal cueing improves gait more than external cueing in healthy adults and people with Parkinson disease

Walking can be challenging for aging individuals and people with neurological disorders such as Parkinson disease (PD). Gait impairment characterized by reduced speed and higher variability destabilizes gait and increases the risk of falls. External auditory cueing provides an effective strategy to improve gait, as matching footfalls to rhythms typically increases gait speed and elicits larger steps, but the need to synchronize to an outside source often has a detrimental effect on gait variability. Internal cueing in the form of singing may provide an alternative to conventional gait therapy. In the present study, we compare the effects of internal and external cueing techniques on forward and backward walking for both people with PD and healthy controls. Results indicate that internal cueing was associated with improvements in gait velocity, cadence, and stride length in the backward direction, and reduced variability in both forward and backward walking. In comparison, external cueing was associated with minimal improvement in gait characteristics and a decline in gait stability. People with gait impairment due to aging or neurological decline may benefit more from internal cueing techniques such as singing as compared to external cueing techniques.

Computing the variations in the self-similar properties of the various gait intervals in Parkinson disease patients

This study has investigated the stride, swing, stance and double support intervals of gait for Parkinson's disease (PD) patients with different levels of severity. Self-similar properties of the gait signal were analyzed to investigate the changes in the gait pattern of the healthy and PD patients. To understand the self-similar property, detrended fluctuation analysis was performed. The analysis shows that the PD patients have less defined gait when compared to healthy. The study also shows that among the stance and swing phase of stride interval, the self-similarity is less for swing interval when compared to the stance interval of gait and decreases with the severity of gait. Also, PD patients show decreased self-similar patterns in double support interval of gait. This suggest that there are less rhythmic gait intervals and a sense of urgency to remain in support phase of gait by the PD patients.

Wearable sensors objectively measure gait parameters in Parkinson's disease

Distinct gait characteristics like short steps and shuffling gait are prototypical signs commonly observed in Parkinson's disease. Routinely assessed by observation through clinicians, gait is rated as part of categorical clinical scores. There is an increasing need to provide quantitative measurements of gait, e.g. to provide detailed information about disease progression. Recently, we developed a wearable sensor-based gait analysis system as diagnostic tool that objectively assesses gait parameter in Parkinson's disease without the need of having a specialized gait laboratory. This system consists of inertial sensor units attached laterally to both shoes. The computed target of measures are spatiotemporal gait parameters including stride length and time, stance phase time, heel-strike and toe-off angle, toe clearance, and inter-stride variation from gait sequences. To translate this prototype into medical care, we conducted a cross-sectional study including 190 Parkinson's disease patients and 101 age-matched controls and measured gait characteristics during a 4x10 meter walk at the subjects' preferred speed. To determine intraindividual changes in gait, we monitored the gait characteristics of 63 patients longitudinally. Cross-sectional analysis revealed distinct spatiotemporal gait parameter differences reflecting typical Parkinson's disease gait characteristics including short steps, shuffling gait, and postural instability specific for different disease stages and levels of motor impairment. The longitudinal analysis revealed that gait parameters were sensitive to changes by mirroring the progressive nature of Parkinson's disease and corresponded to physician ratings. Taken together, we successfully show that wearable sensor-based gait analysis reaches clinical applicability providing a high biomechanical resolution for gait impairment in Parkinson's disease. These data demonstrate the feasibility and applicability of objective wearable sensor-based gait measurement in Parkinson's disease reaching high technological readiness levels for both, large scale clinical studies and individual patient care.

The pathogenic LRRK2 R1441C mutation induces specific deficits modeling the prodromal phase of Parkinson's disease in the mouse

The aim of the present study was to further explore the in vivo function of the Leucine-rich repeat kinase 2 (LRRK2)-gene, which is mutated in certain familial forms of Parkinson's disease (PD). We generated a mouse model harboring the disease-associated point mutation R1441C in the GTPase domain of the endogenous murine LRRK2 gene (LRRK2 R1441C line) and performed a comprehensive analysis of these animals throughout lifespan in comparison with an existing knockdown line of LRRK2 (LRRK2 knockdown line). Animals of both lines do not exhibit severe motor dysfunction or pathological signs of neurodegeneration neither at young nor old age. However, at old age the homozygous LRRK2 R1441C animals exhibit clear phenotypes related to the prodromal phase of PD such as impairments in fine motor tasks, gait, and olfaction. These phenotypes are only marginally observable in the LRRK2 knockdown animals, possibly due to activation of compensatory mechanisms as suggested by in vitro studies of synaptic transmission. Thus, at the organismal level the LRRK2 R1441C mutation does not emerge as a loss of function of the protein, but induces mutation specific deficits. Furthermore, judged by the phenotypes presented, the LRRK2-R1441C knock-in line is a valid preclinical model for the prodromal phase of PD.

Loss of gait control assessed by cognitive-motor dual-tasks: pros and cons in detecting people at risk of developing Alzheimer's and Parkinson's diseases

Alzheimer's and Parkinson's diseases are age-related progressive neurodegenerative diseases of increasing prevalence worldwide. In the absence of curative therapy, current research is interested in prevention, by identifying subtle signs of early-stage neurodegeneration. Today, the field of behavioral neuroscience has emerged as one of the most promising areas of research on this topic. Recently, it has been shown that the exacerbation of gait disorders under dual-task conditions (i.e., simultaneous performance of cognitive and motor tasks) could be a characteristic feature of Alzheimer's and Parkinson's diseases. The cognitive-motor dual-task paradigm during walking allows to assess whether (i) executive attention is abnormally impaired in prodromal Alzheimer's disease or (ii) compensation strategies are used in order to preserve gait function when the basal ganglia system is altered in prodromal Parkinson's disease. This review aims at (i) identifying patterns of dual-task-related gait changes that are specific to Alzheimer's and Parkinson's diseases, respectively, (ii) demonstrating that these changes could potentially be used as prediagnostic markers for disease onset, (iii) reviewing pros and cons of existing dual-task studies, and (iv) proposing future directions for clinical research.

Effects of external rhythmical cueing on gait in patients with Parkinson's disease: a systematic review

Objective: To critically review studies evaluating the effects of external rhythmical cueing on gait in patients with Parkinson's disease.

Methods: Articles published from 1966 to January 2005 were searched by two physiotherapists in MEDLINE, PiCarta, PEDRo, Cochrane, DocOnline, CINAHL and SUMSEARCH. To be included, articles had to investigate the effects of external rhythmical cueing (i.e., auditory, visual or tactile cueing) on gait parameters in patients with idiopathic Parkinson's disease. Both controlled and noncontrolled studies were included. Based on the type of design and methodological quality a meta-analysis or best-evidence synthesis was applied.

Results: Twenty-four studies (total number of patients = 626) out of the 159 screened studies were evaluated in this systematic review. Two out of 24 were randomized controlled trails (RCT), both of high methodological quality. One RCT did not focus specifically on external rhythmical cueing of individual patients with Parkinson's disease, but on group exercises in general, including walking with cues. All other studies were pre-experimental studies. Best-evidence synthesis showed strong evidence for improving walking speed with the help of auditory cues. Insufficient evidence was found for the effectiveness of visual and somatosensory cueing.

Conclusion: Only one high-quality study, specifically focused on the effects of auditory rhythmical cueing, suggesting that the walking speed of patients with Parkinson's disease can be positively influenced. However, it is unclear whether positive effects identified in the laboratory can be generalized to improved activities of daily living (ADLs) and reduced frequency of falls in the community. In addition, the sustainability of a cueing training programme remains uncertain.

Neurologic Music Therapy Training for Mobility and Stability Rehabilitation with Parkinson's Disease - A Pilot Study

Idiopathic Parkinson's Disease (PD) is a progressive condition with gait disturbance and balance disorder as the main symptoms. Previous research studies focused on the application of Rhythmic Auditory Stimulation (RAS) in PD gait rehabilitation. The key hypothesis of this pilot study, however, assumes the major role of the combination of all three Neurologic Music Therapy (NMT) sensorimotor techniques in improving spatio-temporal gait parameters, and postural stability in the course of PD. The 55 PD-diagnosed subjects invited to the study were divided into two groups: 30 in the experimental and 25 in the control group. Inclusion criteria included Hoehn and Yahr stages 2 or 3, the ability to walk independently without any aid and stable pharmacological treatment for the duration of the experiment. In order to evaluate the efficacy of the chosen therapy procedure the following measures were applied: Optoelectrical 3D Movement Analysis, System BTS Smart for gait, and Computerized Dynamic Posturography CQ Stab for stability and balance. All measures were conducted both before and after the therapy cycle. The subjects from the experimental group attended music therapy sessions four times a week for 4 weeks. Therapeutic Instrumental Music Performance (TIMP), Pattern Sensory Enhancement (PSE) and RAS were used in every 45-min session for practicing daily life activities, balance, pre-gait, and gait pattern. Percussion instruments, the metronome and rhythmic music were the basis for each session. The subjects from the control group were asked to stay active and perform daily life activities between the measures. The research showed that the combination of the three NMT sensorimotor techniques can be used to improve gait and other rhythmical activities in PD rehabilitation. The results demonstrated significant improvement in the majority of the spatiotemporal gait parameters in the experimental group in comparison to the control group. In the stability tests with eyes closed, substantial differences were revealed, indicating improvement of proprioception (the sense of body position and movement). These findings suggest a new compensatory strategy for movement and postural control through the use of the auditory system.

Effects of Auditory Rhythm and Music on Gait Disturbances in Parkinson's Disease

Gait abnormalities, such as shuffling steps, start hesitation, and freezing, are common and often incapacitating symptoms of Parkinson’s disease (PD) and other parkinsonian disorders. Pharmacological and surgical approaches have only limited efficacy in treating these gait disorders. Rhythmic auditory stimulation (RAS), such as playing marching music and dance therapy, has been shown to be a safe, inexpensive, and an effective method in improving gait in PD patients. However, RAS that adapts to patients’ movements may be more effective than rigid, fixed-tempo RAS used in most studies. In addition to auditory cueing, immersive virtual reality technologies that utilize interactive computer-generated systems through wearable devices are increasingly used for improving brain–body interaction and sensory–motor integration. Using multisensory cues, these therapies may be particularly suitable for the treatment of parkinsonian freezing and other gait disorders. In this review, we examine the affected neurological circuits underlying gait and temporal processing in PD patients and summarize the current studies demonstrating the effects of RAS on improving these gait deficits.

Qigong exercise may improve sleep quality and gait performance in Parkinson's disease: a pilot study

PURPOSE

Parkinson's disease (PD) involves a variety of motor and non-motor symptoms, several of which, including gait abnormalities and sleep disorders, are generally not adequately managed with standard therapy. This study aimed to determine the impact of Qigong as a potential complementary therapy in the management of gait and sleep-related symptoms in PD.

METHODS

Seven subjects (aged 66.9 ± 8.1 years) with PD participated in a six-week Qigong exercise intervention. Pre- and post-intervention testing was performed to assess sleep quality, cognitive function, fatigue, quality of life, gait performance (stride time, stride length, double support time, and velocity), and gait variability (stride time and length variability).

RESULTS

Following Qigong, subjects showed improvement in some aspects of sleep quality. Fatigue remained unchanged. Gait function was improved by a significant reduction of stride time and a slight increase in stride length. Together these changes resulted in significant improvements to gait velocity. In addition, time spent in double limb support was reduced following the intervention. Overall gait variability improved significantly, particularly in the reduction of stride time variability.

CONCLUSIONS

These results suggest that Qigong may provide benefit for gait performance and sleep quality in PD patients. However, larger, controlled studies are required to determine the immediate and long-term benefits of Qigong for PD sleep and gait problems as well as the impact on other aspects of the disease.

Clinical syndromes: Parkinsonian gait

Disturbances of gait manifest in almost all cases of Parkinson's disease (PD), often leading to loss of mobility and increased mortality. In this review a clinically oriented approach to gait disorders in different stages of PD is presented. In addition, interactions between motor behavior and mental processing will be discussed. Analyzing the clinical features of gait can be helpful to differentiate PD from atypical forms of parkinsonism. Bedside tests to distinguish parkinsonian gait disorders are reviewed. There is still an unmet need to effectively treat complex gait disturbances, which are frequently not responsive to dopamine replacement medication. We thus present current approaches for the management of dopa-refractory gait disorders.

Feasibility study of a wearable system based on a wireless body area network for gait assessment in Parkinson's disease patients

Parkinson's disease (PD) alters the motor performance of affected individuals. The dopaminergic denervation of the striatum, due to substantia nigra neuronal loss, compromises the speed, the automatism and smoothness of movements of PD patients. The development of a reliable tool for long-term monitoring of PD symptoms would allow the accurate assessment of the clinical status during the different PD stages and the evaluation of motor complications. Furthermore, it would be very useful both for routine clinical care as well as for testing novel therapies. Within this context we have validated the feasibility of using a Body Network Area (BAN) of wireless accelerometers to perform continuous at home gait monitoring of PD patients. The analysis addresses the assessment of the system performance working in real environments.

Into the groove: can rhythm influence Parkinson's disease?

Previous research has noted that music can improve gait in several pathological conditions, including Parkinson's disease, Huntington's disease and stroke. Current research into auditory-motor interactions and the neural bases of musical rhythm perception has provided important insights for developing potential movement therapies. Specifically, neuroimaging studies show that rhythm perception activates structures within key motor networks, such as premotor and supplementary motor areas, basal ganglia and the cerebellum - many of which are compromised to varying degrees in Parkinson's disease. It thus seems likely that automatic engagement of motor areas during rhythm perception may be the connecting link between music and motor improvements in Parkinson's disease. This review seeks to describe the link, address core questions about its underlying mechanisms, and examine whether it can be utilized as a compensatory mechanism.

Music and metronome cues produce different effects on gait spatiotemporal measures but not gait variability in healthy older adults

Rhythmic auditory cues including music and metronome beats have been used, sometimes interchangeably, to improve disordered gait arising from a range of clinical conditions. There has been limited investigation into whether there are optimal cue types. Different cue types have produced inconsistent effects across groups which differed in both age and clinical condition. The possible effect of normal ageing on response to different cue types has not been reported for gait. The aim of this study was to determine the effects of both rhythmic music and metronome cues on gait spatiotemporal measures (including variability) in healthy older people. Twelve women and seven men (>65 years) walked on an instrumented walkway at comfortable pace and then in time to each of rhythmic music and metronome cues at comfortable pace stepping frequency. Music but not metronome cues produced a significant increase in group mean gait velocity of 4.6 cm/s, due mostly to a significant increase in group mean stride length of 3.1cm. Both cue types produced a significant but small increase in cadence of 1 step/min. Mean spatio-temporal variability was low at baseline and did not increase with either cue type suggesting cues did not disrupt gait timing. Study findings suggest music and metronome cues may not be used interchangeably and cue type as well as frequency should be considered when evaluating effects of rhythmic auditory cueing on gait. Further work is required to determine whether optimal cue types and frequencies to improve walking in different clinical groups can be identified.

The search for genetic mouse models of prodromal Parkinson's disease

Parkinson's disease is characterized and diagnosed by bradykinetic motor symptoms caused by the loss of dopamine neurons in the substantia nigra. The pathological and non-motor behavioral changes that occur prior to degeneration are less well characterized, although changes in gait, olfaction and cognition have been recognized in familial Parkinson's disease subjects. Gene mutations associated familial Parkinson's disease give rise to mitochondrial changes, altered energy homeostasis and intracellular trafficking deficits, and these can be modeled in transgenic mice. Here we discuss the recent finding of prodromal behavioral disturbances in a PINK1 deficient mouse that manifest prior to dopaminergic cell death and correlate to 5-HT fiber losses and mitochondrial morphological changes. We discuss the representation of the PINK1 deficient mouse and other genetic models to accurately recapitulate early Parkinson's disease. Prodromal symptoms and underlying pathology modeled in mice and cell lines from human subjects may have wide implications for earlier diagnosis. Current and emerging therapies need to be tailored to target both early cognitive and late stage motor symptoms.

Motor signs in the prodromal phase of Parkinson's disease

Relatively subtle deterioration of the motor system likely occurs well before the patient meets established motor criteria for a clinical diagnosis of Parkinson's disease; ie, the occurrence of at least 2 of the cardinal motor deficits: bradykinesia, rigidity, tremor, and/or postural instability. Powerful compensatory mechanisms may mask these clinical symptoms and make them difficult to identify and evaluate in the earliest stages of the illness. This review summarizes our current knowledge of motor signs that are thought to occur in the prodromal phase of Parkinson's disease and suggests how motor assessment batteries could be designed to detect these subclinical motor deficits with a high degree of accuracy and sensitivity.

Both coordination and symmetry of arm swing are reduced in Parkinson's disease

OBJECTIVE

A recent study reporting significantly reduced symmetry in arm swing amplitude in early Parkinson's disease (PD), as measured during single strides in a gait laboratory, led to this investigation of arm swing symmetry and coordination over many strides using wearable accelerometers in PD.

METHODS

Forearm accelerations were recorded while eight early PD subjects and eight Controls performed 8-min walking trials. Arm swing asymmetry (ASA), maximal cross-correlation (MXC), and instantaneous relative phase (IRP) of bilateral arm swing were compared between PD and Controls. Correlations between arm swing measurements (ASA and MXC) and Unified PD Rating Scale (UPDRS) scores were estimated.

RESULTS

PD subjects demonstrated significantly higher ASA (p=0.002) and lower MXC (p<0.001) than Controls. The IRP probability distribution for PD was significantly different than Controls (p<0.001), with an angular standard deviation of 67.2° for PD and 50.6° for Controls. Among PD subjects, ASA was significantly correlated with the UPDRS score for the limbs (R(2)=0.58, p=0.049), whereas MXC was significantly correlated with the tremor subscore of the limbs (R(2)=0.64, p=0.031).

DISCUSSION

The study confirms previously reported higher arm swing asymmetry in PD but also shows there is significantly lower MXC and greater IRP variability, suggesting that reduction in bilateral arm coordination may contribute to clinically observed asymmetry in PD. The differential correlation of clinical measures of motor disability with measurements of arm swing during gait is intriguing and deserves further investigation.

REM sleep behavior disorder is not linked to postural instability and gait dysfunction in Parkinson

To evaluate a potential association of REM-sleep behavior disorder (RBD) with gait and postural impairment in Parkinson's disease (PD). Gait difficulties and postural impairment are frequent in PD and are a major cause of disability. Animal studies indicate a key role of the pedunculopontine nucleus (PPN) in gait, postural control, and REM sleep, and also in the pathophysiology of RBD. In humans, such an association has not been investigated. Twenty-six patients with mild-to-moderate PD (13 with polysomnography confirmed and 13 with excluded RBD), and 20 age-matched healthy controls were prospectively investigated. Gait assessment on a treadmill, and static and dynamic posturography were performed. PD patients with RBD do not differ from those without RBD in gait and postural control. Greater severity of PD or prevalence of gait and postural disturbances in the presence of RBD were not found. RBD was not associated with any particular motor phenotype. We found no association of RBD with gait disturbances and postural impairment. Human gait and postural control and RBD appear to depend upon different neuronal circuits.

Effect of rhythmic auditory stimulation on gait in Parkinsonian patients with and without freezing of gait

Freezing of gait (FOG) in Parkinson's disease (PD) rises in prevalence when the effect of medications decays. It is known that auditory rhythmic stimulation improves gait in patients without FOG (PD-FOG), but its putative effect on patients with FOG (PD+FOG) at the end of dose has not been evaluated yet. This work evaluates the effect of auditory rhythmic stimulation on PD+FOG at the end of dose. 10 PD+FOG and 9 PD-FOG patients both at the end of dose periods, and 10 healthy controls were asked to perform several walking tasks. Tasks were performed in the presence and absence of auditory sensory stimulation. All PD+FOG suffered FOG during the task. The presence of auditory rhythmic stimulation (10% above preferred walking cadence) led PD+FOG to significantly reduce FOG. Velocity and cadence were increased, and turn time reduced in all groups. We conclude that auditory stimulation at the frequency proposed may be useful to avoid freezing episodes in PD+FOG.

The instrumented timed up and go test: potential outcome measure for disease modifying therapies in Parkinson's disease

The Timed Up and Go (TUG) test has been used to assess balance and mobility in Parkinson's Disease (PD). However, it is not known if this test is sensitive to subtle abnormalities present in early stages of the disease, when balance and gait problems are not clinically evident but may be detected with instrumented analysis of movement. We hypothesise that postural transitions and arm swing during gait will be the most sensitive characteristics of the TUG for early PD. In the present study, we instrumented the TUG test (iTUG) using portable inertial sensors, and extended the walking distance from 3 m (traditional TUG) to 7 m. Twelve subjects with early-to-moderate, untreated PD and 12 healthy individuals participated. Our findings show that although the stopwatch measure of TUG duration did not detect any abnormalities in early-to-mid-stage PD, the peak arm swing velocity on the more affected side, average turning velocity, cadence and peak trunk rotation velocity were significantly slower. These iTUG parameters were also correlated with the Unified Parkinson's Disease Rating Motor Scale. Thus, the iTUG test is sensitive to untreated PD and could potentially detect progression of PD and response to symptomatic and disease-modifying treatments.

The use of rhythmic auditory cues to influence gait in patients with Parkinson's disease, the differential effect for freezers and non-freezers, an explorative study

PURPOSE

To study the effect of rhythmic auditory cues on gait in Parkinson's disease subjects with and without freezing and in controls.

METHOD

A volunteer sample of 20 patients (10 freezers, 10 non-freezers) and 10 age-matched controls performed five randomized cued walking conditions in a gait-laboratory. Auditory cues were administered at baseline frequency, at an increased step frequency of 10 and 20% above baseline and at a decreased step frequency of 10 and 20% below baseline. Mean step frequency, walking speed, stride length and double support duration were collected.

RESULTS

Rhythmical auditory cueing induced speed changes in all subjects. Stride length was not influenced by rhythmical auditory cues in controls, whereas patients showed a larger stride length in the -10% condition (p < 0.01). Freezers and non-freezers showed the same response to rhythmical auditory cues. Within group analysis for stride length showed different cueing effects. Stride length decreased at the +10% condition for freezers (p < 0.05), whereas it increased for non-freezers.

CONCLUSIONS

This study points to fact that physiotherapists might need to carefully adjust the cueing frequency to the needs of patients with and without freezing. On the basis of the present results we recommend to lower the frequency setting for freezers, whereas for non-freezers an increase of up to +10% may have potential therapeutic use.

Gait dynamics in Parkinson's disease: common and distinct behavior among stride length, gait variability, and fractal-like scaling

Parkinson's disease (PD) is a common, debilitating neurodegenerative disease. Gait disturbances are a frequent cause of disability and impairment for patients with PD. This article provides a brief introduction to PD and describes the gait changes typically seen in patients with this disease. A major focus of this report is an update on the study of the fractal properties of gait in PD, the relationship between this feature of gait and stride length and gait variability, and the effects of different experimental conditions on these three gait properties. Implications of these findings are also briefly described. This update highlights the idea that while stride length, gait variability, and fractal scaling of gait are all impaired in PD, distinct mechanisms likely contribute to and are responsible for the regulation of these disparate gait properties.

Cueing for freezing of gait in patients with Parkinson's disease: a rehabilitation perspective

Freezing of gait (FOG) has been known to respond favorably to sensory tricks and cues. However, FOG is a complex phenomenon with various motor control deficits at play. In this review, we examined and summarized the currently available evidence for the effectiveness of cueing for FOG to determine its value as a clinical method. The results showed that the immediate effects of cues have no consistent impact but longer periods of cued training may be beneficial. The review also showed (1) the limited statistical power and methodological weakness of the studies involved; (2) measurement difficulties of FOG, and (3) the need to better understand its underlying causal factors. Overall, the findings suggest a smaller capacity for compensation in patients suffering from FOG. Especially when attention is overloaded, the therapeutic window and the practical applicability of cueing seem more limited. These aspects need to be incorporated in the development of future cueing programs designed to alleviate FOG.

Externally provoked freezing of gait in open runways in advanced Parkinson's disease results from motor and mental collapse

Freezing of gait (FOG) in Parkinson's disease (PD) is defined as a sudden inability to maintain effective stepping movements. However, its pathophysiology remains unclear. The objectives are: (1) To assess the contribution of both spatial (walking speed, stride length) and temporal parameters (cadence, stride time) and their coefficients of variation to the genesis of FOG in PD. (2) To evaluate whether and how externally imposed modifications of self-determined gait would elicit FOG. We included ten patients with advanced PD, and with daily off drug FOG episodes. We focused on walking in an open runway. For each subject, we manipulated gait by externally imposing four changes in walking speed and four changes in cadence. FOG episodes, often with a long duration of more than 5-s, were observed mostly under conditions with a high imposed cadence. The steps that immediately preceded these episodes were mainly characterized by an increase in cadence and an increase in stride length variability. The results also underscore that FOG can be elicited in a laboratory setting when patients are placed under considerable strain, at least in advanced stages of PD. Patients were unable to adequately negotiate the extreme imposed cadence condition, and this resulted in frequent FOG episodes, even while walking in an open runway. Placing advanced PD patients into extreme imposed conditions leads to a motor wise and mental collapse response, culminating in FOG. Future work should establish the relevance of these findings for the more common forms of FOG, including brief episodes during turning or gait initiation.

Rhythmic auditory stimulation modulates gait variability in Parkinson's disease

Patients with Parkinson's disease (PD) walk with a shortened stride length and high stride-to-stride variability, a measure associated with fall risk. Rhythmic auditory stimulation (RAS) improves stride length but the effects on stride-to-stride variability, a marker of fall risk, are unknown. The effects of RAS on stride time variability, swing time variability and spatial-temporal measures were examined during 100-m walks with the RAS beat set to 100 and 110% of each subject's usual cadence in 29 patients with idiopathic PD and 26 healthy age-matched controls. Carryover effects were also evaluated. During usual walking, variability was significantly higher (worse) in the patients with PD compared with the controls (P < 0.01). For the patients with PD, RAS at 100% improved gait speed, stride length and swing time (P < 0.02) but did not significantly affect variability. With RAS at 110%, reductions in variability were also observed (P < 0.03) and these effects persisted 2 and 15 min later. In the control subjects, the positive effects of RAS were not observed. For example, RAS increased stride time variability at 100 and 110%. These results demonstrate that RAS enables more automatic movement and reduces stride-to-stride variability in patients with PD. Further, these improvements are not simply a by-product of changes in speed or stride length. After walking with RAS, there also appears to be a carryover effect that supports the possibility of motor plasticity in the networks controlling rhythmicity in PD and the potential for using RAS as an intervention to improve mobility and reduce fall risk.

Postural control, gait, and dopamine functions in parkinsonian movement disorders

Balance impairments and falls, which are common in patients who have parkinsonian movement disorders, are a serious threat to the health of these individuals. However, the underlying mechanisms cannot be fully explained by presynaptic dopaminergic denervation, because balance impairment is at least responsive to L-dopa therapy. This article reviews the latest clinically relevant literature relating postural control, gait, and dopamine in patients who have parkinsonian movement disorders.

Marked alterations in the gait timing and rhythmicity of patients withde novoParkinson's disease

Little is known about the gait characteristics of subjects with de novo Parkinson's disease (PD). We hypothesized that alterations in the spatio-temporal characteristics of gait will already be quantifiable in these patients. The gait of 35 patients with idiopathic PD (mean age 60 years) who were in the early stages of the disease (Hoehn and Yahr stage 1.8 +/- 0.5, median 2.0, range 1.0-2.5) and were not yet treated with any anti-parkinsonian medications were compared with the gait of age- and sex-matched healthy controls (n = 22). The patients walked more slowly and with reduced swing times while also exhibiting increased left/right swing asymmetry and marked inconsistencies in the timing of gait. By contrast, significant group differences in the peak forces at heel-strike and in the stride-to-stride variability of the ground reaction forces (a reflection of muscle output consistency) were not observed. These findings indicate that in de novo PD, an altered gait pattern is observed, even though dramatic changes in the gait pattern may not yet be apparent visually (e.g. fairly intact gait speed). Furthermore, the results demonstrate that the observed alterations are not just side-effects of treatments or complications of the disease. Instead, there is evidence for motor programming deficits in gait, as revealed by increased gait variability and asymmetry in timing. PD apparently impinges on the regulation of a consistent gait rhythm, even early in the course of the disease when observed alterations are not the result of any pharmacologic treatment.

Evaluation of the effect of training using auditory stimulation on rhythmic movement in Parkinsonian patients—a combined motor and [18F]-FDG PET study

INTRODUCTION

A programme of rehabilitation using auditory cues has previously been shown to decrease movement variability in the gait of Parkinsonian patients.

OBJECTIVE AND METHODS

We studied the temporal variability of finger-tapping and gait in 9 patients with Parkinson's disease (PD) before and after they undertook a physical rehabilitation programme. Positron Emission Tomography (PET) using 2-deoxy-2[(18)F]fluoro-D-glucose (FDG) was performed in these subjects to look for changes in metabolic brain activity after completion of the rehabilitation program.

RESULTS

The reduction of variability was seen not only in gait but also other repetitive movements such as finger tapping. Furthermore, here we show differences in resting regional cerebral glucose utilisation in these patients compared to healthy controls (significant hypometabolism-p < 0.001-for the PD group in the right parietal and temporal lobes, left temporal and frontal lobes and a hypermetabolism in the left cerebellum) and specific changes following the improvements in repetitive movement abilities (significant metabolic increment-p < 0.001-in the PD group in the right cerebellum and in the right parietal and temporal lobes).

CONCLUSIONS

Although our study does not allow us to draw firm conclusions, it provides new information on the neural basis of auditory stimulation in PD. Our results extend those from previous studies to show improvement in the temporal variability of two types of rhythmic movements after participation by PD patients in a physical rehabilitation programme, along with changes in glucose uptake in several brain areas involved in sensorimotor processing.

Startle responses in Parkinson patients during human gait

Falls frequently occur in patients with Parkinson's disease (Bloem et al. 2001). One potential source for such falls during walking might be caused by the reaction to loud noises. In normal subjects startle reactions are well integrated in the locomotor activity (Nieuwenhuijzen et al. 2000), but whether this is also achieved in Parkinson patients is unknown. Therefore, in the present study, the startle response during walking was studied in eight patients with Parkinson's disease and in eight healthy subjects. To examine how startle reactions are incorporated in an ongoing gait pattern of these patients, unexpected auditory stimuli were presented in six phases of the step cycle during walking on a treadmill. For both legs electromyographic activity was recorded from biceps femoris and tibialis anterior. In addition, we measured the stance and swing phases of both legs, along with the knee angles of both legs and the left ankle angle. In all subjects and all muscles, responses were detected. The pattern of the responses, latency, duration, and phase-dependent modulation was similar in both groups. However, the mean response amplitude was larger in patients due to a smaller habituation rate. No correlation was found between the degree of habituation and disease severity. Moreover, a decreased habituation was already observed in mildly affected patients, indicating that habituation of the startle response is a sensitive measure of Parkinson's disease. The results complement the earlier findings of reduced habituation of blink responses in Parkinson's disease. With respect to behavioral changes in healthy subjects we observed that startle stimuli induced a shortening of the step cycle and a decrease in range of motion. In the patient group, less shortening of the subsequent step cycle and no decrease in range of motion of the knee and ankle was seen. It is argued that the observed changes might contribute to the high incidence of falls in patients with Parkinson's disease.

Autism and Asperger's disorder: Are they movement disorders involving the cerebellum and/or basal ganglia?

Autism and Asperger's disorder (AD) are childhood developmental disorders of unknown aetiology. Autism and AD share several behavioural features, and it is not clear whether they are distinct disorders or variants of the same disorder. Recent studies indicate that disordered movement may be another feature of autism and AD, and that this may reflect dysfunction within the frontostriatal and/or cerebellar motor circuits. While disordered movement in autism and AD has been examined in a variety of ways, it is relatively under-researched compared to the cognitive, affective, and behavioural disturbances seen in these disorders. This review examines the role of the frontostriatal and cerebellar motor systems in the behavioural features of autism and AD, with gait as a proxy, and discusses difficulties with their diagnosis and their possible pathogenesis.

Temporal variability of gait in Parkinson disease: effects of a rehabilitation programme based on rhythmic sound cues

It has been suggested that sequential movements in patients with Parkinson's disease (PD) might be improved by the effects of external rhythmic cues. We studied spatiotemporal gait parameters and temporal gait variability in patients with PD and control subjects under different walking conditions in order to investigate whether rhythmic auditory cues could improve temporal variability. A total of 30 subjects were recruited, comprising 15 patients with idiopathic PD and 15 control subjects with no history of neurological disorder. As an indicator for temporal stability, we used the coefficient of variability (CV=standard deviation/mean X 100) of recorded intervals between two consecutive steps (gait variability). After control values were obtained, subjects underwent a Physical Rehabilitation Programme (PRP) consisting of a variety of motor tasks performed in combination with rhythmic sounds with different cadences. Sessions lasted 1h/day, five times a week for a period of four consecutive weeks. At the end of the PRP subjects were evaluated again. Following completion of the programme the patients' coefficients of variability improved significantly for the preferred gait (gait: t=2.950, p=0.011) but were not significantly different from those obtained in control subjects (gait: t=3.873, p=0.391). These results are consistent with and extend prior studies of rhythmic auditory facilitation in PD and suggest a valuable method of improving gait timing in these patients.

Immediate effects of speed-dependent treadmill training on gait parameters in early Parkinson's disease

OBJECTIVE

To compare the immediate effects of different training interventions on gait parameters in patients with early Parkinson's disease (PD).

DESIGN

Randomized, multiple intervention crossover pilot study.

SETTING

A rehabilitation center for adult persons with neurologic disorders.

PARTICIPANTS

Seventeen patients with early PD (Hoehn and Yahr stages I through III) and gait disturbances.

INTERVENTION

Patients were randomly assigned to varying sequences of the following interventions over 4 consecutive days: structured speed-dependent treadmill training (STT), limited progressive treadmill training (LTT), conventional gait training (CGT), and a control intervention.

MAIN OUTCOME MEASURES

Basic gait parameters (overground walking speed and stride length at self-adapted speeds) and parameters of gait analysis based on vertical ground reaction forces.

RESULTS

STT and LTT improved all basic gait parameters and the double stance duration compared with preintervention values (P<.05). No changes were found after CGT and the control intervention (P<.05). Significantly higher gains were observed in all basic gait parameters after STT and LTT when compared with CGT and the control intervention (P<.05). Additionally, a greater reduction of double stance duration was found after STT than after the control intervention (P<.001). No significant differences in gains were observed between STT and LTT, or between CGT and the control intervention, in all gait parameters.

CONCLUSION

The main disturbances of gait in PD, namely, speed and stride length, can be improved through a single intervention of STT or LTT, but not through CGT and the control intervention.

Cortical and subcortical networks underlying syncopated and synchronized coordination revealed using fMRI. Functional magnetic resonance imaging

Inherent differences in difficulty between on the beat (synchronization) and off the beat (syncopation) coordination modes are well known. Synchronization is typically quite easy and, once begun, may be carried out with little apparent attention demand. Syncopation tends to be difficult, even though it has been described as a simple, phase-shifted version of a synchronized pattern. We hypothesize that syncopation, unlike synchronization, is organized on a cycle-by-cycle basis, thereby imposing much greater preparatory and attentional demands on the central nervous system. To test this hypothesis we used fMRI to measure the BOLD response during syncopation and synchronization to an auditory stimulus. We found that the distribution of cortical and subcortical areas involved in intentionally coordinating movement with an external metronome depends on the timing pattern employed. Both synchronized and syncopated patterns require activation of contralateral sensorimotor and caudal supplementary motor cortices as well as the (primarily ipsilateral) cerebellum. Moving off the beat, however, requires not only additional activation of the cerebellum but also the recruitment of another network comprised of the basal ganglia, dorsolateral premotor, rostral supplementary motor, prefrontal, and temporal association cortices. No areas were found to be more active during synchronization than syncopation. The functional role of the cortical and subcortical regions areas involved in syncopation supports the hypothesis that whereas synchronization requires little preparation and monitoring, syncopated movements are planned and executed individually on each perception-action cycle.

Quantitative analysis of gait in Parkinson's disease: a pilot study on the effects of bilateral sub-thalamic stimulation

Four patients with Parkinson's disease who had a Subthalamic Nucleus (STN) stimulator implanted and four age-matched controls underwent gait analysis using a three-dimensional system. STN stimulation substantially improved most of the key variables in the patients, without producing inefficient compensatory movements of the trunk. A reduction of ankle power production during push off was the most persistent abnormality seen when the patients were stimulated. We also found a reduction of trunk lateral bending and torsion when the patients were not stimulated when compared with controls.

Abnormalities of the spatiotemporal characteristics of gait at the onset of freezing in Parkinson's disease

We investigated the spatiotemporal variables of gait leading up to freezing. Gait analysis was carried out on 14 patients with Parkinson's disease in the off phase of the medication cycle. A computerised, three-dimensional gait analysis system was used to measure the walking pattern. After several trials of normal walking with voluntary stopping, distracting manoeuvres and obstacles on the walkway were used to provoke freezing or festination. The gait variables of normal (off phase), festinating, prestop, and prefreezing strides were analysed using analysis of variance for repeated-measures. Cadence was excessively increased (68%) and stride length decreased (69%) during festination compared with normal off walking; a pattern which remained pronounced when comparing prefreezing strides with normal stopping. Analysing in more detail the three steps before a freeze, we found a progressive decrease of stride length and stable cadence rates and proportions of double support phases. The relationship between cadence and stride length exhibited an exponential increase of cadence with a decreasing stride length during festination and freezing. Results suggest that freezing is caused by a combination of an increasing inability to generate stride length superimposed on a dyscontrol of the cadence of walking.

The biomechanics and motor control of gait in Parkinson disease

Parkinson disease is a progressive neurological condition characterised by hypokinesia (reduced movement), akinesia (absent movement), tremor, rigidity and postural instability. These movement disorders are associated with a slow short-stepped, shuffling gait pattern. Analysis of the biomechanics of gait in response to medication, visual cues, attentional strategies and neurosurgery provides insight into the nature of the motor control deficit in Parkinson disease and the efficacy of current therapeutic interventions. In this article we supplement a critical evaluation of the Parkinson disease gait literature with two case examples. The first case describes the kinematic gait response of an individual with Parkinson disease to visual cues in the "off" phase of the levodopa medication cycle. The second case investigates the biomechanics and motor control of turning during walking in a patient with Parkinson disease compared with elderly and young control subjects. The results are interpreted in light of the need for gait analysis to investigate complex functional walking tasks rather than confining assessment to straight line walking, which has been the trend to date.

Sociocultural differences in gait

Transcultural differences in routine motor behavior and movement disorders have rarely been assessed. In the present study gait was studied in 47 healthy inhabitants of Tyrol living in rural or semi-urban (Innsbruck, Austria) settings and 43 healthy subjects residing in Berlin, Germany. In addition, gait was assessed in 23 patients in early stages of idiopathic Parkinson's disease (11 in Berlin, 12 in Innsbruck). Healthy subjects in Berlin showed faster gait velocity than their counterparts in Tyrol, and patients with Parkinson's disease were slightly slower than their respective healthy peers in both environments. Surprisingly, patients with Parkinson's disease from Berlin had significantly faster walking speeds than both patients and healthy control subjects from Tyrol. High gait tempo in parkinsonian patients from Berlin was characterized by fast step-rates and short strides. Differences in normal gait in different sociocultural settings are thus reflected in parkinsonian slowing of gait.