Characteristics of postural control and locomotion of patients with vascular and Alzheimer-type dementias

Postural stability in the cognitively impaired elderly: A systematic review of the literature

INTRODUCTION

The aim of this study was to review the literature and critically analyse publications connecting cognitive impairment with postural stability.

METHODS

Four electronic databases were searched. The inclusion criteria comprised the relation between the process of maintaining balance and cognitive impairment.

RESULTS

Of the 153 selected articles, 15 met the inclusion criteria. In 83% of publications, cognitive status was determined with the use of the Mini-Mental State Examination. In eight publications, postural stability was examined using force plates. Other methods used to test the balance were functional tests, i.e. the Berg Balance Scale or the Balance Evaluation Systems Test.

CONCLUSION

As the choice of methodology varies significantly, it is difficult to attempt an objective comparison between different studies. There is a clear need for the normalisation of methods used to assess the degree of dementia and to assess postural stability among this group of people.

Establishment of a Drosophila AD model

Alzheimer's disease (AD) is the most common form of dementia that affects people's health greatly. Though amyloid precursor protein (APP) has been implicated in the pathogenesis of AD, the exact role of APP and its underlying mechanism in AD progression have remained largely elusive. Drosophila melanogaster has been extensively used as a model organism to study a wide range of human diseases including AD. In this protocol, we expressed full length human APP in the Drosophila nervous system and examined its effect on locomotion and choice ability. We found that expression of APP produced locomotion defects in larvae as measured by plate crawling ability assay (PCA), and in adult flies as monitored by plate cycling ability assay (CLA). In addition, expression of APP results in male courtship choice (MCC) defect, since wild-type males court preferentially toward young virgin females over old ones, while APP-expressing males failed to show this preference. This protocol enables us to screen for novel AD candidate genes as well as therapeutic compounds to ameliorate the disease.