Low-Cost Robotic Assessment of Visuo-Motor Deficits in Alzheimer's Disease

A low-cost robotic interface was used to assess the visuo-motor performance of patients with Alzheimer's disease (AD). Twenty AD patients and twenty age-matched controls participated in this work. The battery of tests included simple reaction times, position tracking, and stabilization tasks performed with both hands. The regularity, velocity, visual and haptic feedback were manipulated to vary movement complexity. Reaction times and movement tracking error were analyzed. Results show a marked group effect on a subset of conditions, in particular when the patients could not rely on the visual feedback of hand movement. The visuo-motor performance correlated with the measures of global cognitive functioning and with different memory-related abilities. Our results support the hypothesis that the ability to recall and use visuo-spatial associations might underlie the impairment in complex motor behavior that has been reported in AD patients. Importantly, the patients had preserved learning effects across sessions, which might relate to visuo-motor deficits being less evident in every-day life and clinical assessments. This robotic assessment, lasting less than 1 h, provides detailed information about the integrity of visuo-motor abilities. The data can aid the understanding of the complex pattern of deficits that characterizes this pervasive disease.

The Early Presentation of Dementia in People with Down Syndrome: a Systematic Review of Longitudinal Studies

Adults with Down syndrome (DS) are at a very high risk of developing early onset Alzheimer's disease (AD) due to trisomy of chromosome 21. AD is preceded by a prolonged prodromal "pre-clinical" phase presenting with clinical features that do not fulfil the diagnostic criteria for AD. It is important to clinically characterise this prodromal stage to help early detection of the disease as neuropathology of AD is almost universal by the fifth decade in DS. There is a lack of knowledge of the trajectory of decline associated with the onset of dementia in this population and early signs may be overlooked or misdiagnosed, negatively affecting the quality of life of those affected and the use of early pharmacological or psychosocial interventions. The objective of this systematic review is to evaluate the published literature on longitudinal data in order to identify the cognitive and behavioural changes occurring during the prodromal and early stages of AD in this population. Fifteen peer-reviewed articles met the inclusion criteria, including a total number of 831 participants, with the duration between baseline and follow up varying from 1 year to 47 years. Results suggest that, compared to the general population for which short-term (episodic) memory loss is the most common indicator associated with the onset of AD, in people with DS, executive dysfunction and Behavioural and Psychological Symptoms of Dementia (BPSD) are commonly observed during pre-clinical and early stages and may precede memory loss. The review highlights the importance of using a broad spectrum of assessments in the context of heterogeneity of symptoms. Theoretical and practical implications are discussed, as well as the need for further research.

Sensory and motor secondary symptoms as indicators of brain vulnerability

In addition to the primary symptoms that distinguish one disorder from the next, clinicians have identified, yet largely overlooked, another set of symptoms that appear across many disorders, termed secondary symptoms. In the emerging era of systems neuroscience, which highlights that many disorders share common deficits in global network features, the nonspecific nature of secondary symptoms should attract attention. Herein we provide a scholarly review of the literature on a subset of secondary symptoms––sensory and motor. We demonstrate that their pattern of appearance––across a wide range of psychopathologies, much before the full-blown disorder appears, and in healthy individuals who display a variety of negative symptoms––resembles the pattern of appearance of network abnormalities. We propose that sensory and motor secondary symptoms can be important indicators of underlying network aberrations and thus of vulnerable brain states putting individuals at risk for psychopathology following extreme circumstances.

Detection of activity limitations in older adults with MCI or Alzheimer's disease through evaluation of perceived difficulty in use of everyday technology: a replication study

OBJECTIVES AND METHODS

Earlier research indicates that the ability to use everyday technology (ET) may be sensitive to subtle functional change. People with mild cognitive impairment (MCI) have been identified as significantly more disabled in ET use compared to controls, albeit less disabled than people with dementia. The aim of this study was to investigate the replicability of these findings using an improved version of the Everyday Technology Use Questionnaire (ETUQ) to compare perceptions of relevance and difficulty in ET use in participants with MCI or Alzheimer's disease (AD) and controls. Additional aims were to explore the validity of ETUQ, and the relationships between perceived difficulty in ET use and cognitive status, mood state, and involvement in everyday life activities. In total, 118 participants were included, 37 with AD, 37 with MCI, and 44 controls.

RESULTS

Analyses confirmed that the rating scale of the ETUQ functioned well. The three groups overlapped but differed significantly in their perceptions of ETs relevance (p < 0.05) as well as of difficulties in ET use (p < 0.001). Moderate correlations were also found between ETUQ measures and cognitive status, mood, and involvement in activities, the strongest being that between ETUQ measures and involvement in activities (r = 0.563).

CONCLUSION

Taken together, the findings underscore the plausibility of disability already in people with MCI, as the use of ET strongly correlates to involvement in activities. It is therefore important that professionals who meet older adults with cognitive impairment take this aspect of function into account in assessments and targeted interventions.

Impairment and abuse of elderly by staff in long-term care in Michigan: evidence from structural equation modeling

Elder abuse in long-term care has become a very important public health concern. Recent estimates of elder abuse prevalence are in the range of 2% to 10% (Lachs & Pillemer, 2004), and current changes in population structure indicate a potential for an upward trend in prevalence (Malley-Morrison, Nolido, & Chawla, 2006; Post et al., 2006). More than 20 years ago, Karl Pillemer called for sociological research on patient maltreatment in nursing homes and provided an overview model for the conduct of such research (Pillemer, 1988). The research literature since then has not provided the definitive model to account for patient maltreatment that Pillemer hoped for. Instead, it has produced a laundry list of risk factors that includes the patient's functional disability, cognitive impairment, social isolation, age, race, income, family background, life events, dementia, and depression (Dyer, Pavlik, Murphy, & Hyman, 2000; Lachs & Pillemer, 2004; Lachs,Williams, Obrien, Hurst, & Horwitz, 1997; Pavlik, Hyman, Festa, & Dyer, 2001; Schofield & Mishra, 2003). However, no theory exists to place these factors in a causal structure that relates the factors to each other and to whether abuse occurs. This study is a first step in that direction. Nine hypotheses were generated focusing on the effects of two dimensions of impairment--(a) physical and cognitive and (b) age and behavior problems--on susceptibility to abuse among elderly in long-term care.The relationships between factors and from factors to susceptibility to abuse are specified in a structural equation model where "susceptibility to abuse," "physical impairment," and "cognitive impairment" are latent variables, and behavior problems and age are directly measured.

Occupational performance and awareness of disability in mild cognitive impairment or dementia

Limited awareness of disabilities is common in mild cognitive impairment and dementia. In order to get a broader base in planning interventions, it is important to consider a person's awareness of his/her disability encountered in performance. The aim of this study was to examine the relationship between occupational performance and awareness of disability in older adults with mild cognitive impairment or dementia. Thirty-five older adults were evaluated with the AMPS (Assessment of Motor and Process Skills) and with the AAD (Assessment of Awareness of Disability). Many-faceted Rasch models generated individual measures of ADL performance and awareness of disability. Non-parametric correlation statistics were used to analyse the relationships. The findings showed that there was an overall positive relationship between occupational performance and awareness of disability. However, individual variations in the sample implied that limitations in performance were not equivalent to a limited awareness of disability. In conclusion, awareness of disability should be individually evaluated when planning interventions together with clients and their families.

Differences in activities of daily living performance between long-term pediatric sarcoma survivors and a matched comparison group on standardized testing

BACKGROUND

In a cross-sectional study examining late effects of pediatric sarcoma therapy, long-term survivors were evaluated on their activities of daily living (ADL) performance.

PROCEDURE

Thirty-two persons with Ewing sarcoma family of tumors, rhabdomyosarcoma, and non-rhabdomysarcoma-soft tissue sarcoma enrolled an average of 17 years after treatment. Participants were evaluated using the Assessment of Motor and Process Skills (AMPS) 1, a standardized observational evaluation of ADL task performance. Means and 95% confidence intervals for ADL motor and ADL process ability measures were calculated for four groups: (1) sarcoma survivors, (2) "well" adults matched for age and gender, (3) "well" adults matched for gender that were 10 years older, and (4) "well" adults matched for gender that were 20 years older.

RESULTS

ADL motor ability was significantly lower for sarcoma survivors than for the age- and gender-matched comparison group (P < 0.05). There was no significant difference between ADL motor ability of sarcoma survivors and the comparison group 10 years older, but sarcoma survivors had significantly better ADL motor ability (P < 0.05) than the oldest comparison group (20 years older). Sarcoma survivors had significantly worse ADL process ability than the age-matched group (P < 0.05). There was no difference in ADL process ability between the sarcoma survivors and comparison groups that were 10 and 20 years older.

CONCLUSIONS

This first report of a clinical evaluation of ADL limitation in pediatric sarcoma survivors treated with intensive multimodal cancer therapy suggests that influences on performance of daily life activities are more common than previously reported.