[A Comparison Study of Ace -R and Brain Scanning in Aiding Memory Clinics in Clinical Diagnosis of Dementia]

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Acknowledgement

I would take this opportunity to thank my research supervisor, family and friends for their support and guidance without which this research would not have been possible.

DECLARATION

I, [type your full first names and surname here], declare that the contents of this dissertation/thesis represent my own unaided work, and that the dissertation/thesis has not previously been submitted for academic examination towards any qualification. Furthermore, it represents my own opinions and not necessarily those of the University.

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Executive Summary

Objectives

The Addenbrooke's Cognitive Examination - Revised (ACE-R) is a dementia screening tool. The objectives of this study were to investigate rater accuracy in scoring the ACE-R in terms of its total and subscale scores and to examine whether scoring accuracy is affected by participant experience of using the ACE-R.

Methods

Three filmed vignettes of the ACE-R being administered to older adult actors (mock patients) were used to assess scoring accuracy across multiple raters. The vignettes had a pre-determined 'true score'. Study participants were required to complete ACE-R scoring sheets for each vignette.

Results

Participant scores were compared with the pre-determined true scores as a means of measuring scoring accuracy. The results indicated that the majority of participant scores were either the same as or within a few points of the true scores. However, when compared to the true scores, participant total scores differed significantly on two out of the three vignettes. Scoring accuracy was lowest for the Memory subscale of the ACE-R. Scoring accuracy issues were also identified for the Visuospatial and Attention and orientation subscales. Individual items which had low scoring accuracy were identified.

Discussion

The majority of participants scored the same as or within a few points of the true scores, such deviation is likely to be clinically acceptable, providing over-emphasis is not placed on cut off scores. Professionals using the ACE-R should ensure they are familiar with the scoring guidelines for the items highlighted in this study as having low scoring accuracy.

Table of Contents

CHAPTER 1: INTRODUCTION8

The role of cognitive screening in dementia diagnosis15

Measurement issues in cognitive screening tools16

The ACE-R as a dementia screening tool18

ACE-R reliability18

CHAPTER 2: THEORETICAL FRAMEWORK20

Cognitive functions20

The concept of intelligence in neuropsychology22

Classes of cognitive functions23

Receptive functions24

Memory and learning25

Thinking30

Expressive functions31

Interdependence of cognitive functions33

Mental activity variables33

Consciousness33

Attention34

Activity rate36

Cognitive performance36

The assessment of cognitive performance by the Dementia Rating Scale37

Initiation/Perseveration (I/P) subscale39

Memory (MEM) subscale42

Cognitive impairment44

Cognitive decline in normal aging45

Mild cognitive impairment45

The dementia syndrome47

Definition47

Diagnosis48

The Dementia Evaluation49

Neuropsychological testing50

Alzheimer's Disease53

Neuropathological features53

Neuropsychological markers54

Clinical and Radilogical presentation55

Objective57

CHAPTER 3: RESEARCH METHODOLOGY58

Participants and methods58

Control subjects58

Subject selection58

Procedure and methods59

Dementia patients59

Subject selection59

Procedure and methods60

Data analysis63

CHAPTER 4: RESULTS64

Demographic characteristics75

Addenbrooke's Cognitive Examination Revised77

Alzheimer's Disease Assessment Scale-Cognitive Section78

Cambridge Cognitive Examination78

Mattis Dementia Rating Scale79

Montreal Cognitive Assessment80

Neurobehavioral Cognitive Screening Examination or Cognistat80

The Repeatable Battery for the Assessment of Neuropsychological Status82

Seven-Minute Screen83

Moderator analyses84

Vote counting87

Subtest analyses87

CHAPTER 4: DISCUSSION89

CHAPTER 5: CONCLUSION98

REFERENCES100

Chapter 1: Introduction

Dementia refers to global cognitive decline, characteristic of progressive conditions such as Alzheimer's disease. There is a general consensus that early dementia diagnosis is desirable because it enables earlier intervention and gives “people the opportunity to make ...