Measurement of accelerometry-based gait parameters in people with and without dementia in the field: a technical feasibility study.

BACKGROUND: Gait analyses are an important tool to diagnose diseases or to measure the rehabilitation process of patients. In this context, sensor-based systems, and especially accelerometers, gain in importance. They are able to improve objectiveness of gait analyses. In clinical settings, there is usually a supervisor who gives instructions to the patients, but this can have an influence on patients' gait. It is expected that this effect will be smaller in field studies. OBJECTIVE: Aim of this study was to capture and evaluate gait parameters measured by a single waist-mounted accelerometer during everyday life of subjects. METHODS: Due to missing ground-truth in unsupervised conditions, another external criterion had to be chosen. Subjects of two different groups were considered: patients with dementia (DEM) and active older people (ACT). These groups were chosen, because of the expected difference in gait. The idea was to quantify the expected difference of accelerometric-based gait parameters. Gait parameters were e.g. velocity, step frequency, compensation movements, and variance of the accelerometric signal. RESULTS: Ten subjects were measured in each group. The number of walking episodes captured was 1,187 (DEM) vs. 1,809 (ACT). The compensation and variance parameters showed an AUC value (Area Under the Curve) between 0.88 and 0.92. In contrast, velocity and step frequency performed poorly (AUC values of 0.51 and 0.55). It was possible to classify both groups using these parameters with an accuracy of 89.2%. CONCLUSION: The results showed a much higher amount of walking episodes in field studies compared to supervised clinical trials. The classification showed a high accuracy in distinguishing between both groups.

Primary gait ignition disorder: report of three cases.

Gait ignition failure (GIF) classifications all had major limitations. Few years ago, a new and simpler classification was proposed by Liston. The aim of this paper is to discuss three GIF patients with respect to this new classification. All three patients presented with hesitation to start walking and turning and their neurological examination revealed start and turn hesitation without any other abnormality. We classified our patients according to Liston's classification as ignition apraxia, which enabled us to approach the patients in a practical way. This classification helps to understand the underlying pathologies and combines clinical characteristics and pathophysiology. We reported our experience with pergolide in the treatment of patients suffering from primary GIF and underline the fact that more research is needed on the treatment of this condition.

Developmental coordination impairments in adulthood.

The aim of this study was to extend the understanding of Developmental Coordination Disorder (DCD) into adulthood. We recruited 19 adults aged between 18 and 65 who had received diagnoses of DCD or dyspraxia or who self-reported as having motor impairments consistent with a history of DCD, together with age- and gender-matched controls. Participants were given tests of manual dexterity, handwriting, construction, obstacle avoidance, dynamic balance, static balance, dual task performance, ball skills, reaction time, movement time and sequencing. As a group, adults with DCD performed more poorly than controls across all tasks. Slowness and variability of movement was a pervasive feature of their performance and many individuals had considerable problems with sequencing and with dual task performance. A discriminant function analysis conducted using six performance measures correctly classified participants as car drivers or non-drivers. Adults do retain motor difficulties and these can exclude them from important activities of daily living.

A new classification of higher level gait disorders in patients with cerebral multi-infarct states.

BACKGROUND: cerebral multi-infarct states may lead to gait disorders in the absence of cognitive impairment. Where these gait disorders occur in the absence of neurological signs they have been termed gait apraxia or more recently higher-level gait disorders. In this paper we hypothesise three main types based on presumptive sites of anatomical damage: (a) Ignition Apraxia, where damage is predominantly in the supplementary motor area and its connections, with good responses to external clues; (b) Equilibrium Apraxia, where damage is predominantly in the pre-motor area in its connections, with poor responses to external cues and (c) Mixed Gait Apraxia. SUBJECTS: the clinical features and measured gait parameters of 13 patients with cerebral multi-infarct states and higher-level gait disorder are described (7 with Ignition Apraxia and 6 with Equilibrium Apraxia) along with those of 6 healthy elderly control subjects. METHODS: baseline gait characteristics were assessed on a walkway, which measured the following: step lengths, width of base and velocity. RESULTS: measured baseline gait parameters support the above hypothesis. CONCLUSIONS: it is suggested, though not proven, that patients with Ignition Apraxia could have problems with internal cueing due to lesions in the supplementary motor area or its connections whereas those with Equilibrium Apraxia could have dysfunction predominantly in the pre-motor area and its connections.