Handedness and Anatomical and hemodynamic Asymmetyries of the Carotid Arteries

166 Pages·2014·4.45 MB·English

Handedness and Anatomical and Hemodynamic Asymmetries of the Carotid Arteries

Anica Jansen van Vuuren- JNSANI001

A dissertation submitted in partial fulfilment of the requirements for the award of the degree of
Master of Arts (MA) in Neuropsychology
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Faculty of Humanities
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University of Cape Town
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2014
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COMPULSORY DECLnARATION
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This work has not been previously submitted in whole, or in part, for the award of any degree. It
is my own work. Each significant contribution to, and quotation in, this dissertation from the
work, or works, of other people has been attributed, and has been cited and referenced.

Signature: Date:
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The copyright of this thesis vests in the author. No
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quotation from it or information derived from it is to be

published without full acknowledgeement of the source.
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The thesis is to be used for private study or non-
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commercial research purposes only.

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Published by the Universit y of Cape Town (UCT) in terms
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of the non-exclusive license granted to UCT by the author.
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Acknowledgements

Prof Mark Solms: Supervisor of this project. I thank him for his time, effort, and his guidance on
this project. His hard work is truly appreciated.
Geometric study: I would like to thank Dr Ozyar Ameen, Morton and Partners Radiologists, Prof
Leonie Scholtz from Scholtz and Partners Diagnostic Radiologists, Dr Albert L. Spanengberg
and Casper van Vyk from Burger Radiologists, and Kevin Ernstzen from Groote Schuur hospital
for providing CTA scans for the geometric analysis.
Hemodynamic study: I thank Nadia Davids for her help in administrating the Doppler ultrasound
and Dr Nadraj Naidoo for making the equipment available for the hemodynamic analysis.
Harry Crossley Foundation Research Fellowship: This project would not have been possible
without the financial assistance provided by the Harry Crossley Foundation.
Abbreviations
A - Mean artery angle
MEAN
A - Accumulative artery angle
SUM
BP - Blood pressure
BT - Brachiocephalic trunk
CCA - Common carotid artery
CTA - Computed tomography angiography
DEV - Mean angle deviation from vertical
MEAN
DEV - Accumulative angle deviation from vertical
SUM
D - Maximum diameter
MAX
D - Minimum diameter
MIN
ECA - Common carotid artery
ICA - Internal carotid artery
LCCA - Left common carotid artery
LECA - Left external carotid artery
LICA - Left internal carotid artery
LQ - Laterality quotient
LSA - Left subclavian artery
RCCA - Right common carotid artery
RCCA-BT - Combined right common carotid artery and brachiocephalic trunk
RECA - Right external carotid artery
RICA - Right internal carotid artery
RSA - Right subclavian artery
TI - Target index
V - Peak diastolic velocity
DIA
V - Mean velocity
MEAN
V - End systolic velocity
SYS
Table of contents
Abstract .................................................................................................................................... i
Introduction .............................................................................................................................. 1
Chapter 1: Literature Review ................................................................................................... 3
What is Handedness? ...................................................................................................... 4
Handedness and Hemispheric Lateralisation ................................................................. 5
Early Theories Regarding Handedness and Asymmetrical Blood Flow ........................ 6
Handedness and Asymmetrical Blood Flow .................................................................. 9
Asymmetries in cerebral blood flow ....................................................................... 9
Asymmetries at rest .......................................................................................... 10
Asymmetries during motor activity .................................................................. 11
Asymmetries during cognition .......................................................................... 12
Cerebral venous drainage ........................................................................................ 12
Asymmetric arterial branching ................................................................................ 13
Asymmetries in arterial blood flow ......................................................................... 15
Vertebral arteries ............................................................................................. 16
Internal carotid arteries ................................................................................... 17
Common carotid arteries ................................................................................. 19
Vascular pathology .................................................................................................. 20
Situs-inversus ................................................................................................... 21
Evidence towards a causal relationship ................................................................... 21
Summary and Conclusions ............................................................................................. 23
Overall Aim and Hypothesis .................................................................................................... 24

Chapter 2: Geometric Characterisation .................................................................................... 25
Pilot study ....................................................................................................................... 25
Specific Aims and Hypotheses ................................................................................................ 26
Design and Methods ................................................................................................................ 27
Design and Setting .......................................................................................................... 27
Participants ..................................................................................................................... 27
Exclusion criteria .................................................................................................... 28
Materials ......................................................................................................................... 29
Revised Edinburgh Handedness Inventory ............................................................. 29
CTA Scanning ......................................................................................................... 29
Imaging software ..................................................................................................... 29
Procedure ........................................................................................................................ 29
Administration of Handedness Inventory ............................................................... 29
CTA Scanning ......................................................................................................... 30
Image processing and vessel analysis ..................................................................... 30
Length ............................................................................................................... 30
Diameter and area ........................................................................................... 30
Angle ................................................................................................................. 31
Resistance to blood flow ................................................................................... 31
Statistical Analysis ....................................................................................................... 32
Ethical Considerations .................................................................................................. 34
Results ...................................................................................................................................... 36
Conventional Branching Patterns ................................................................................... 37
Sex differences ........................................................................................................ 38
Vessel length ........................................................................................................... 39
Diameter measures .................................................................................................. 42
Minimum diameter ........................................................................................... 43
Maximum diameter ........................................................................................... 43
Arterial angle measures ........................................................................................... 44
Artery angle deviation from the vertical .......................................................... 44
Artery curvature ............................................................................................... 44
Resistance to blood flow ......................................................................................... 45
Discriminant Function Analysis ..................................................................................... 45
Geometric Changes with Age ......................................................................................... 47
Unconventional Branching Patterns ............................................................................... 50
Bovine arch ............................................................................................................. 50
Aberrant left vertebral artery ................................................................................... 53
Aberrant right subclavian artery .............................................................................. 54
Inclusion of all branching patterns .......................................................................... 55
Discussion ................................................................................................................................ 57
Implications .................................................................................................................... 60

Chapter 3: Hemodynamic Characterisation ............................................................................. 63
Specific Aims and Hypotheses ................................................................................................ 64
Design and Methods ................................................................................................................ 65
Design and Setting .......................................................................................................... 65
Participants ..................................................................................................................... 65
Exclusion criteria .................................................................................................... 66
Materials ......................................................................................................................... 67
Ultrasound measurements ....................................................................................... 67
Imaging software ..................................................................................................... 67
Blood pressure ......................................................................................................... 67
Revised Edinburgh Handedness Inventory ............................................................. 67
Target Tests ............................................................................................................. 67
Procedure ........................................................................................................................ 68
Doppler ultrasound .................................................................................................. 68
Blood pressure ......................................................................................................... 70
Administration of Handedness Inventory................................................................ 70
Target Tests ............................................................................................................. 71
Target speed ..................................................................................................... 71
Target accuracy ................................................................................................ 71
Statistical Analysis ........................................................................................................ 72
Ethical Considerations .................................................................................................. 74
Results ...................................................................................................................................... 75
Sex differences ............................................................................................................... 77
Blood Pressure ................................................................................................................ 77
Common Carotid Arteries .............................................................................................. 79
Diameter .................................................................................................................. 79
Mean flow velocity .................................................................................................. 82
Resistance and Pulsitility indices ............................................................................ 83
Volume flow rate ..................................................................................................... 84
Internal Carotid Arteries ................................................................................................. 84
Diameter .................................................................................................................. 84
Mean flow velocity .................................................................................................. 87
Resistance and Pulsitility indices ............................................................................ 88
Volume flow rate ..................................................................................................... 88
External Carotid Arteries ................................................................................................ 89
Diameter .................................................................................................................. 89
Mean flow velocity .................................................................................................. 92
Resistance and Pulsitility indices ............................................................................ 93
Volume flow rate ..................................................................................................... 94
Discriminant Function Analysis ..................................................................................... 94
Volume Flow Rate Prediction of Hand-proficiency ....................................................... 96
Speed Target Index .................................................................................................. 96
Accuracy Target Index ............................................................................................ 98
Discussion ................................................................................................................................ 101
Implications .................................................................................................................... 106

Summary and Conclusion ........................................................................................................ 107