Detection of Parkinson’s disease tremor-onset with a frequency analysing artificial neural network

Deep Brain Stimulator devices are becoming widely used for therapeutic benefits in movement disorders such as Parkinson's disease. Prolonging the battery life span of such devices could dramatically reduce the risks and accumulative costs associated with surgical replacement. This paper demonstrates how an artificial neural network can be trained using pre-processing frequency analysis of deep brain electrode recordings to detect the onset of tremor in Parkinsonian patients. Implementing this solution into an 'intelligent' neurostimulator device will remove the need for continuous stimulation currently used, and open up the possibility of demand-driven stimulation. Such a methodology could potentially decrease the power consumption of a deep brain pulse generator.

Excess burden of constipation in Parkinson's disease: A pilot study

An analysis was undertaken of clinic-based questionnaires that asked people with Parkinson's disease and a control group of older people without a known neurological condition about their experiences of constipation. People with Parkinson's disease report higher constipation on a validated objective measure, the Rome criterion (59% vs. 20.9%); a behavioral indicator, laxative-taking (38.4% vs. 14.2%); and subjective self-report of being always or often concerned by it (33.4% vs. 6.1%). Many people with Parkinson's disease experience constipation problems but they may not bring these to the attention of their healthcare providers. More research is required to understand the causes and management options. (C) 2006 Movement Disorder Society.

Health-related quality of life in Huntington's disease: a comparison of two generic instruments, SF-36 and SIP

Whereas several clinical endpoints in monitoring the response to treatment in patients with Huntington's disease (HD) have been explored, there has been a paucity of research in the quality of life in such patients. The aim of this study was to validate the use of two generic health-related quality of life instruments (the Short Form 36 health survey questionnaire [SF-36] and the Sickness Impact Profile [SIP]) and to evaluate their psychometric properties. We found that both instruments demonstrated acceptable convergent validity and reliability for patients and carers. However, there was an advantage in using the SF-36 because of its more robust construct validity and test-retest reliability; furthermore, motor symptoms appeared to influence some strictly nonmotor dimensions of the SIP. On a pragmatic level, the SF-36 is shorter and quicker to administer and, therefore, easier for patients at various stages of the disease to complete. Thus, the SF-36 would appear to be the recommended instrument of choice for patients with HD and their carers, although further work needs to be done to investigate the sensitivity of this instrument longitudinally. (C) 2004 Movement Disorder Society.

Huntington's disease patients have selective problems with insight

The objective of this study was to determine insight in patients with Huntington's disease (HD) by contrasting patients' ability to rate their own behavior with their ability to rate a person other than themselves. HD patients and carers completed the Dysexecutive Questionnaire (DEX), rating themselves and each other at two time points. The temporal stability of these ratings was initially examined using these two time points since there is no published test-retest reliability of the DEX with this Population to date. This was followed by a comparison of patients' self-ratings and carer's independent ratings of patients by performing correlations with patients' disease variables, and in exploratory factor analysis was conducted on both sets of ratings. The DEX showed good test-retest reliability, with patients consistently and persistently underestimating the degree of their dysexecutive behavior, but not that of their carers. Patients' self-ratings and caters' ratings of patients both showed that dysexecutive behavior in HD can be fractionated into three underlying components (Cognition, Self-regulation, Insight), and the relative ranking of these factors was similar for both data sets. HD patients consistently underestimated the extent of only their own dysexecutive behaviors relative to carers' ratings by 26%, but were similar in ascribing ranks to the components of dysexecutive behavior. (c) 2005 Movement Disorder Society.

For better or worse: the effect of levodopa on speech in Parkinson's disease

While the beneficial effect of levodopa on traditional motor control tasks have been well documented over the decades. its effect on speech motor control has rarely been objectively examined and the existing literature remains inconclusive. This paper aims to examine the effect of levodopa on speech in patients with Parkinson's disease. It was hypothesized that levodopa would improve preparatory motor set related activity and alleviate hypophonia. Patients fasted and abstained from levodopa overnight. Motor examination and speech testing was performed the following day, pre-levodopa during their "off' state, then at hourly intervals post-medication to obtain the best "on" state. All speech stimuli showed a consistent tendency for increased loudness and faster rate during the "on" state, but this was accompanied by a greater extent of intensity decay. Pitch and articulation remained unchanged. Levodopa effectively upscaled the overall gain setting of vocal amplitude and tempo, similar to its well-known effect on limb movement. However, unlike limb movement, this effect on the final acoustic product of speech may or may not be advantageous, depending on the existing speech profile of individual patients. (C) 2007 Movement Disorder Society.

A Gentle/S approach to robot assisted neuro-rehabilitation

Movement disorders (MD) include a group of neurological disorders that involve neuromotor systems. MD can result in several abnormalities ranging from an inability to move, to severe constant and excessive movements. Strokes are a leading cause of disability affecting largely the older people worldwide. Traditional treatments rely on the use of physiotherapy that is partially based on theories and also heavily reliant on the therapists training and past experience. The lack of evidence to prove that one treatment is more effective than any other makes the rehabilitation of stroke patients a difficult task. UL motor re-learning and recovery levels tend to improve with intensive physiotherapy delivery. The need for conclusive evidence supporting one method over the other and the need to stimulate the stroke patient clearly suggest that traditional methods lack high motivational content, as well as objective standardised analytical methods for evaluating a patient's performance and assessment of therapy effectiveness. Despite all the advances in machine mediated therapies, there is still a need to improve therapy tools. This chapter describes a new approach to robot assisted neuro-rehabilitation for upper limb rehabilitation. Gentle/S introduces a new approach on the integration of appropriate haptic technologies to high quality virtual environments, so as to deliver challenging and meaningful therapies to people with upper limb impairment in consequence of a stroke. The described approach can enhance traditional therapy tools, provide therapy "on demand" and can present accurate objective measurements of a patient's progression. Our recent studies suggest the use of tele-presence and VR-based systems can potentially motivate patients to exercise for longer periods of time. Two identical prototypes have undergone extended clinical trials in the UK and Ireland with a cohort of 30 stroke subjects. From the lessons learnt with the Gentle/S approach, it is clear also that high quality therapy devices of this nature have a role in future delivery of stroke rehabilitation, and machine mediated therapies should be available to patient and his/her clinical team from initial hospital admission, through to long term placement in the patient's home following hospital discharge.

An item response analysis of the motor and behavioral subscales of the unified Huntington's disease rating scale in huntington disease gene expansion carriers

Although the Unified Huntington's Disease Rating Scale (UHDRS) is widely used in the assessment of Huntington disease (HD), the ability of individual items to discriminate individual differences in motor or behavioral manifestations has not been extensively studied in HD gene expansion carriers without a motor-defined clinical diagnosis (ie, prodromal-HD or prHD). To elucidate the relationship between scores on individual motor and behavioral UHDRS items and total score for each subscale, a nonparametric item response analysis was performed on retrospective data from 2 multicenter longitudinal studies. Motor and behavioral assessments were supplied for 737 prHD individuals with data from 2114 visits (PREDICT-HD) and 686 HD individuals with data from 1482 visits (REGISTRY). Option characteristic curves were generated for UHDRS subscale items in relation to their subscale score. In prHD, overall severity of motor signs was low, and participants had scores of 2 or above on very few items. In HD, motor items that assessed ocular pursuit, saccade initiation, finger tapping, tandem walking, and to a lesser extent, saccade velocity, dysarthria, tongue protrusion, pronation/supination, Luria, bradykinesia, choreas, gait, and balance on the retropulsion test were found to discriminate individual differences across a broad range of motor severity. In prHD, depressed mood, anxiety, and irritable behavior demonstrated good discriminative properties. In HD, depressed mood demonstrated a good relationship with the overall behavioral score. These data suggest that at least some UHDRS items appear to have utility across a broad range of severity, although many items demonstrate problematic features.

Health-related quality of life in Huntington's disease: which factors matter most?

The aim of this article was to determine which aspects of Huntington's disease (HD) are most important with regard to the health-related quality of life (HrQOL) of patients with this neurodegenerative disease. Seventy patients with HD participated in the study. Assessment comprised the Unified Huntington's Disease Rating Scale (UHDRS) motor, cognitive and functional capacity sections, and the Beck Depression inventory. Mental and physical HrQOL were assessed using summary scores of the SF-36. Multiple regression analyses showed that functional capacity and depressive mood were significantly associated with HrQOL, in that greater impairments in HrQOL were associated with higher levels of depressive mood and lower functional capacity. Motor symptoms and cognitive function were not found to be as closely linked with HrQOL. Therefore, it can be concluded that, depressive mood and greater functional incapacity are key factors in HrQOL for people with HD, and further longitudinal investigation will be useful to determine their utility as specific targets in intervention studies aimed at improving patient HrQOL, or whether other mediating variables. As these two factors had a similar association with the mental and physical summary scores of the SF-36, this generic HrQOL measure did not adequately capture and distinguish the true mental and physical health-related HrQOL in HD.

Impairment in movement skills of children with autistic spectrum disorders

We undertook this study to explore the degree of impairment in movement skills in children with autistic spectrum disorders (ASD) and a wide IQ range. Movement skills were measured using the Movement Assessment Battery for Children (M-ABC) in a large, well defined, population-derived group of children (n=101: 89 males,12 females; mean age 11y 4mo, SD 10mo; range 10y-14y 3mo) with childhood autism and broader ASD and a wide range of IQ scores. Additionally, we tested whether a parent-completed questionnaire, the Developmental Coordination Disorder Questionnaire (DCDQ), was useful in identifying children who met criteria for movement impairments after assessment (n=97 with complete M-ABCs and DCDQs). Of the children with ASD, 79% had definite movement impairments on the M-ABC; a further 10% had borderline problems. Children with childhood autism were more impaired than children with broader ASD, and children with an IQ less than 70 were more impaired than those with IQ more than 70. This is consistent with the view that movement impairments may arise from a more severe neurological impairment that also contributes to intellectual disability and more severe autism. Movement impairment was not associated with everyday adaptive behaviour once the effect of IQ was controlled for. The DCDQ performed moderately well as a screen for possible motor difficulties. Movement impairments are common in children with ASD. Systematic assessment of movement abilities should be considered a routine investigation.

Attention processes in children with movement difficulties, reading difficulties or both

Reading difficulties (RD) and movement difficulties (MD) co-occur more often in clinical populations than expected for independent disorders. In this study, we investigated the pattern of association between attentional processes, RD and MD in a population of 9 year old school children. Children were screened to identify index groups with RD, MD or both, plus a control group. These groups were then tested on a battery of cognitive attention assessments (TEA-Ch). Results confirmed that the occurrence of RD and MD was greater than would be predicted for independent disorders. Additionally, children with MD, whether or not combined with RD, had poor performance on all attention measures when compared with typically developing children. Children with RD only, were no poorer on measures of attention than typical children. The results are discussed with respect to approaches proposed to account for the co-occurrence of disorders.

Parent-reported gastro-intestinal symptoms in children with autism spectrum disorders

The objective of this study is to investigate whether parentally-reported gastro-intestinal (GI) symptoms are increased in a population-derived sample of children with autism spectrum disorders (ASD) compared to controls. Participants included 132 children with ASD and 81 with special educational needs (SEN) but no ASD, aged 10-14 years plus 82 typically developing (TD) children. Data were collected on GI symptoms, diet, cognitive abilities, and developmental histories. Nearly half (weighted rate 46.5 %) of children with ASD had at least one individual lifetime GI symptom compared with 21.8 % of TD children and 29.2 % of those with SEN. Children with ASD had more past and current GI symptoms than TD or SEN groups although fewer current symptoms were reported in all groups compared with the past. The ASD group had significantly increased past vomiting and diarrhoea compared with the TD group and more abdominal pain than the SEN group. The ASD group had more current constipation (when defined as bowel movement less than three times per week) and soiling than either the TD or SEN groups. No association was found between GI symptoms and intellectual ability, ASD severity, ASD regression or limited or faddy diet. Parents report more GI symptoms in children with ASD than children with either SEN or TD children but the frequency of reported symptoms is greater in the past than currently in all groups.