BackgroundHuntington's disease (HD) is a fatal inherited neurodegenerative disease, caused by a

National Institute on Aging, National Institute of Neurological Disorders and Stroke, Canadian Institutes of Health Research, Italian Ministry of Health, UK National Institute for Health Research, National Health and Medical Research Council of Australia, and the French National Research Agency.

The aim of this study was to identify determinants of functional disability, patient’s quality of life (QoL) and caregivers’ burden in Huntington’s disease (HD). Eighty HD patients participated in the study. Motor and behavioral disturbances as well as cognitive impairment were assessed using motor, behavioral and cognitive parts of the Unified Huntington Disease Rating Scale (UHDRS); Hamilton Depression Rating Scale was used to assess depression. Disability, health-related QoL and the impact of the disease on the caregivers were assessed using the following methods: UHDRS Functional Assessment Score, SF-36 Scale and Caregiver Burden Inventory. Multiple regression analysis showed that motor disturbances, cognitive impairment, apathy and disease duration were the independent predictors of disability. Depression and cognitive disturbances were the determinants of patient’s QoL, while motor disturbances and depression were the predictors of the caregiver burden. Patient’s disability and QoL as well as caregivers’ burden should be taken into consideration while planning treatment strategy and the results of the present study show that the predictors of those treatment targets are different.

Self-awareness of memory function is relatively well preserved in PD, but is negatively affected by depressive symptoms. Patient-proxy discrepancies increase also with disease severity, degree of memory problems and cognitive control deficits. Caregivers seem to be unaware of the specificity of memory problems in PD and report only some of them, mainly those related to verbal recall.

Individuals suffering from Huntington's disease (HD) have been shown to present with poor self-awareness of a variety of symptoms. The aim of this study was to better assess the self-awareness of motor symptoms and activities of daily living (ADL) impairment in HD, in comparison to Parkinson's disease (PD) and cervical dystonia (CD). In particular, the anosognosia/anosodiaphoria of involuntary movements has been investigated. Self-awareness was tested in 23 patients with HD by comparing patient and caregiver ratings in reference to clinical control groups (25 PD with dyskinesias, PDdys; 21 PD without dyskinesias, PDndys; and 20 with CD). Patients were assessed neurologically by relevant rating scales. Self-awareness was tested using a scale based on 15 films demonstrating 3 types of motor symptoms (chorea/dyskinesias, parkinsonism, torticollis) as well as the Self-Assessment Parkinson's Disease Disability Scale. General cognitive status, verbal learning, cognitive control, and mood were also analyzed. Our results indicate that self-awareness of choreic movements was affected more severely in HD than in PDdys, despite comparable cognitive status. Patient-proxy agreement on ADL impairment was roughly similar in all clinical groups. The results are discussed in the context of orbitofrontal-limbic pathology as a potential trigger of anosognosia/anosodiaphoria in individuals with HD.

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The genetic factors studied were not associated with cognitive status in PD patients. Only age and Hcy plasma levels were found to be independent risk factors predisposing individuals to PD dementia. However, COMT: rs4680: A>G and rs4633: C>T polymorphisms were found to significantly affect PD risk, and the MTHFR 677C>T polymorphism helped determine plasma Hcy concentrations.

People with Huntington's disease (HD) may show reduced awareness of physical and mental changes in themselves. This article reviews the evidence for loss of awareness (anosognosia) in an attempt to elucidate its characteristics and possible underlying mechanisms. It is shown that defective awareness occurs across domains. People with HD may under-report the presence or severity of involuntary movements, under-estimate cognitive impairment and deny behavioural change. Nevertheless, awareness is not all or none. Moreover, it may be affected differentially for different symptom domains and emerge at different stages of disease, raising the possibility of distinct contributory mechanisms. Findings of an inverse relationship between insight and severity of disease suggest that cognitive impairment, in particular executive dysfunction, may be an important contributory factor. Evidence has accrued to support this argument. However, cognitive impairment cannot fully account for patients' lack of awareness of involuntary movements. Findings that patients accurately report consequences but not the experience of involuntary movements, and better acknowledge their presence when watching videotapes of themselves suggests that physiological factors play an important role. The putative role of denial as a coping mechanism is discussed. Recognition by clinicians of deficient self-awareness is crucial because of its implications for diagnosis and optimal clinical management of HD.