Louise Allan

Bio: Louise Allan is an academic researcher from University of Exeter. The author has contributed to research in topics: Dementia & Dementia with Lewy bodies. The author has an hindex of 27, co-authored 91 publications receiving 3014 citations. Previous affiliations of Louise Allan include Newcastle University & University of Oxford.

Incidence and prediction of falls in dementia: a prospective study in older people.

Abstract: Competing Interests: The authors have declared that no competing interests exist. Funding: LA was supported by the Alzheimer's Society, UK and ER by the Alzheimer's Research Trust. Additional funding was provided by the Medical Research Council, UK. The authors' work was independent of the funding bodies.

Motor subtype and cognitive decline in Parkinson’s disease, Parkinson’s disease with dementia, and dementia with Lewy bodies

Abstract: Background: A previous cross sectional study found over-representation of a postural instability gait difficulty (PIGD) motor subtype in Parkinson’s disease patients with dementia (PDD) and dementia with Lewy bodies (DLB), compared with Parkinson’s disease (PD). Aims: (1) To examine rates of cognitive and motor decline over two years in PD (n = 40), PDD (n = 42) and DLB (n = 41) subjects, compared with age matched controls (n = 41), (2) to record whether motor phenotypes of PD, PDD, and DLB subjects changed during the study, (3) to find out if cognitive and motor decline in PD was associated with baseline motor subtype, and (4) to report the incidence of dementia in PD patients in relation to baseline motor subtype. Results: Most of PDD and DLB participants were PIGD subtype at baseline assessment. In the non-demented PD group, tremor dominant (TD) and PIGD subtypes were more evenly represented. Cognitive decline over two years was greater in PDD and DLB groups (mean decline in MMSE − 4.5 and − 3.9, respectively), compared with PD ( − 0.2) and controls (−0.3). There was an association between PIGD subtype and increased rate of cognitive decline within the PD group. Of 40 PD patients, 25% of the 16 PIGD subtype developed dementia over two years, compared with none of the 18 TD or six indeterminate phenotype cases (χ 2 = 6.7, Fisher’s exact test p Conclusion: A PIGD motor subtype is associated with a faster rate of cognitive decline in PD and may be considered a risk factor for incident dementia in PD.

Prevalence and Severity of Gait Disorders in Alzheimer's and Non-Alzheimer's Dementias

Abstract: Objectives: To compare the prevalence, severity, and type of gait and balance disorders in Alzheimer's disease (AD), vascular dementia (VaD), Parkinson's disease with dementia (PDD), dementia with Lewy bodies (DLB), Parkinson's disease without dementia (PD), and age-matched controls. Design: Cross-sectional. Setting: Secondary care clinics in geriatric psychiatry, neurology, and geriatrics. Participants: Two hundred forty-five participants aged 65 and older (AD, n=40; VaD, n=39; PDD, n=46; DLB, n=32; PD, n=46; and controls, n=42). Measurements: Prevalence and severity of gait and balance disorders were assessed using the Tinetti gait and balance scale. The types of gait disorders in each diagnostic group were classified using the Nutt et al. classification. Results: Gait and balance disorders were more common with PDD (93%), VaD (79%), and DLB (75%) than with PD (43%) and AD (25%) and in controls (7%). The risk of gait and balance disorder was higher in the non-Alzheimer's dementia groups (VaD, PDD, and DLB) than in the AD group (odds ratio=15 (95% confidence interval=6–37). If a gait disorder was present in mild dementia (Cambridge Examination for Mental Disorders of the Elderly cognitive subsection score >65), this was diagnostic of non-Alzheimer's dementia, with sensitivity of 78% and specificity of 100%. Non-Alzheimer's dementia groups had worse Tinetti gait and balance scores than the AD group (all P<.001). The types of gait disorders discriminated between non-Alzheimer's dementias. Conclusion: The findings support the idea that gait and balance assessment may augment the diagnostic evaluation of dementia.

Autonomic dysfunction in dementia

Abstract: Background: There are no studies of autonomic function comparing Alzheimer’s disease (AD), vascular dementia (VAD), dementia with Lewy bodies (DLB) and Parkinson’s disease dementia (PDD). Aims: To assess cardiovascular autonomic function in 39 patients with AD, 30 with VAD, 30 with DLB, 40 with PDD and 38 elderly controls by Ewing’s battery of autonomic function tests and power spectral analysis of heart rate variability. To determine the prevalence of orthostatic hypotension and autonomic neuropathies by Ewing’s classification. Results: There were significant differences in severity of cardiovascular autonomic dysfunction between the four types of dementia. PDD and DLB had considerable dysfunction. VAD showed limited evidence of autonomic dysfunction and in AD, apart from orthostatic hypotension, autonomic functions were relatively unimpaired. PDD showed consistent impairment of both parasympathetic and sympathetic function tests in comparison with controls (all p Conclusion: Autonomic dysfunction occurs in all common dementias but is especially prominent in PDD with important treatment implications.

Clinical diagnostic criteria for dementia associated with Parkinson's disease.

Abstract: Dementia has been increasingly more recognized to be a common feature in patients with Parkinson's disease (PD), especially in old age. Specific criteria for the clinical diagnosis of dementia associated with PD (PD-D), however, have been lacking. A Task Force, organized by the Movement Disorder Study, was charged with the development of clinical diagnostic criteria for PD-D. The Task Force members were assigned to sub-committees and performed a systematic review of the literature, based on pre-defined selection criteria, in order to identify the epidemiological, clinical, auxillary, and pathological features of PD-D. Clinical diagnostic criteria were then developed based on these findings and group consensus. The incidence of dementia in PD is increased up to six times, point-prevelance is close to 30%, older age and akinetic-rigid form are associated with higher risk. PD-D is characterized by impairment in attention, memory, executive and visuo-spatial functions, behavioral symptoms such as affective changes, hallucinations, and apathy are frequent. There are no specific ancillary investigations for the diagnosis; the main pathological correlate is Lewy body-type degeneration in cerebral cortex and limbic structures. Based on the characteristic features associated with this condition, clinical diagnostic criteria for probable and possible PD-D are proposed.

MDS Clinical Diagnostic Criteria for Parkinson's Disease (S19.001)

Abstract: Objective To present the International Parkinson and Movement Disorder Society (MDS) Clinical Diagnostic Criteria for Parkinson9s disease. Background Although several diagnostic criteria for Parkinson9s disease have been proposed, none have been officially adopted by an official Parkinson society. Moreover, the commonest-used criteria, the UK brain bank, were created more than 25 years ago. In recognition of the lack of standard criteria, the MDS initiated a task force to design new diagnostic criteria for clinical Parkinson9s disease. Methods/Results The MDS-PD Criteria are intended for use in clinical research, but may also be used to guide clinical diagnosis. The benchmark is expert clinical diagnosis; the criteria aim to systematize the diagnostic process, to make it reproducible across centers and applicable by clinicians with less expertise. Although motor abnormalities remain central, there is increasing recognition of non-motor manifestations; these are incorporated into both the current criteria and particularly into separate criteria for prodromal PD. Similar to previous criteria, the MDS-PD Criteria retain motor parkinsonism as the core disease feature, defined as bradykinesia plus rest tremor and/or rigidity. Explicit instructions for defining these cardinal features are included. After documentation of parkinsonism, determination of PD as the cause of parkinsonism relies upon three categories of diagnostic features; absolute exclusion criteria (which rule out PD), red flags (which must be counterbalanced by additional supportive criteria to allow diagnosis of PD), and supportive criteria (positive features that increase confidence of PD diagnosis). Two levels of certainty are delineated: Clinically-established PD (maximizing specificity at the expense of reduced sensitivity), and Probable PD (which balances sensitivity and specificity). Conclusion The MDS criteria retain elements proven valuable in previous criteria and omit aspects that are no longer justified, thereby encapsulating diagnosis according to current knowledge. As understanding of PD expands, criteria will need continuous revision to accommodate these advances. Disclosure: Dr. Postuma has received personal compensation for activities with Roche Diagnostics Corporation and Biotie Therapies. Dr. Berg has received research support from Michael J. Fox Foundation, the Bundesministerium fur Bildung und Forschung (BMBF), the German Parkinson Association and Novartis GmbH.

Clinical Diagnosis of Alzheimer's Disease

Abstract: There are a number of ways in which a clinical diagnosis of dementia of the Alzheimer type can be made – the application of clinical criteria is the commonest but ancillary techniques such as neuroima

Conscientiousness and health-related behaviors: a meta-analysis of the leading behavioral contributors to mortality.

Abstract: Previous research has established conscientiousness as a predictor of longevity (H. S. Friedman et al., 1993; L. R. Martin & H. S. Friedman, 2000). To better understand this relationship, the authors conducted a meta-analysis of conscientiousness-related traits and the leading behavioral contributors to mortality in the United States (tobacco use, diet and activity patterns, excessive alcohol use, violence, risky sexual behavior, risky driving, suicide, and drug use). Data sources were located by combining conscientiousness-related terms and relevant health-related behavior terms in database searches as well as by retrieving dissertations and requesting unpublished data from electronic mailing lists. The resulting database contained 194 studies that were quantitatively synthesized. Results showed that conscientiousness-related traits were negatively related to all risky health-related behaviors and positively related to all beneficial health-related behaviors. This study demonstrates the importance of conscientiousness' contribution to the health process through its relationship to health-related behaviors.