MINISTRY OF EDUCATION & TRAINING MINISTRY OF DEFENCE
108 INSTITUTE OF CLINICAL MEDICAL AND PHARMACEUTICAL SCIENCES
VU DUY LAM
ESTIMATING PYRAMIDAL TRACT LESIONS AND
SOME DIFFUSION TENSOR IMAGING INDEXS
RELATED TO MOTOR FUNCTION IN
ISCHEMIC STROKE PATIENTS
Speciality : Medical Imaging
Code : 62.72.01.66
SUMMARY OF THE THESIS
HÀ NỘI - 2019
THIS THESIS IS FINISHED IN 108 INSTITUTE OF CLINICAL
MEDICAL AND PHARMACEUTICAL SCIENCES
Name of supervisor:
1. MD, PhD, Ass. Prof. Lam Khanh
2. MD, Ass. Prof. Vu Long
Reviewer 1: ……………………………………………..................
Reviewer 2: ……………………………………………..................
Reviewer 3: ……………………………………………..................
The thesis will be upholded by hospital council at:
h date month year 2018
Can find out more about this thesis in:
1. National Library
2. Library of 108 Institute of clinical Medical and
Pharmaceutical sciences.
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POSITION OF THE PROBLEM
Importance of the problem:
Cerebral infarction is a severe diease which is the 3rd most
common cause of mortality in Viet Nam after cancer and myocardial
infarction. Ischemic stroke makes some serious sequelae, 50% alive
patients got paralytic symptoms and depended on the helping of the
community.
Motor paralysis is a symptom highly related to the damage of the
pyramidal tract. In the past, the diagnosis of the pyramidal injury
mostly depended on the Babinski sign (+). The medical imaging of
the pyramid was very difficult, because it had the same density and
signal with the white matter in CT and MRI imagings.
The invention of DTI can display the pathway of nervers in the
brain and applying this technique can evaluate the damage of the
tract, study the relationship between the pyramidal damage with
patient’s motor function recovery which help doctors to make a right
prognosis, have an effective treatment stratery and reduce patient’s
sequela. Therefor, we performed this research: “Estimating
pyramidal tract lesions and some Diffusion Tensor Imaging indexs
related to motor function in ischemic stroke patients” in 108 Institute
of Clinical Medical and Pharmaceutical Sciences, where had a
specialist stroke center and a MRI 3.0 Tesla with DTI sequence.
Aim of the thesis
1. Describe the imaging characteristics of the neural tract lesions
in DTI inischemic stroke patients compared to normal people.
2. Estimate the relation between some DTI indexs to motor
function in ischemic stroke patients.
Contribution of the thesis: This is the first research in Viet Nam
about the damage of pyramidal tract in MRI.
Contribution in radiology: Develop a new technique in radiology.
Contribution in treatment: Help to prognose the chance of
motor recovery to make an effective treatment strategy.
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Presentation of the thesis
The thesis comprises 116 pages, dealing with 2 pages for Position
of the Problem, 30 pages for the Overview, 17 pages for the Subjects
and Research Method, 32 pages for the Study Results, 28 pages for
the Discussion, 2 pages for the Conclusions. There are 45 tables, 18
charts, 28 images of the study design. There are 114 references,
including 13Vietnamese documents and 101 English documents.
Chapter 1: OVERVIEW
1.1. Anatomy
The pyramidal tract is the most important motor pathway in the
human brain. The pyramidal tract includes both the motor cortex and
the motor pathways.
1.1.1. The motor cortex
Classically the motor cortex is an area of the frontal lobe located
in the anterior to the central sulcus. It contains the primary motor
cortex, the premotor cortex, the supplementary motor area.
1.1.1.1. The primary motor cortex
The primary motor cortex is located between the precentral sulcus
and central sulcus include central gyrus and the paracentral lobule.
Anatomically, the precentral gyrus can be divided into four
segments: the inferior segment, the middle segment, the superior
segment, the paracentral segment
In function, each the segment of the precentral gyrusis a functionl
unit control a partof the body. The inferior segment: functional unit
of the face; the middle segment: functional unit of the hand and arm;
the superior segmentfunctional unit of the trunk; the paracentral
segment: functional unit of the leg.
1.1.1.2. The premotor cortex: The premotor cortex is in front of the
primary motor cortex, patially locate in the mesial aspect of
hemisphere anterior to the paracentral lobule.
1.1.1.3. The supplementary motor area
The supplementary motor area (SMA) is located in the mesial
aspect of the first frontal gyrus, anterior to the primary motor cortex
of lower extremity and above the cingulate sulcus and behind the
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premotor cortex. The SMA is linked with the contralateral SMA
through the commissural fibers of the corpus callosum.
1.1.2. Motor pathways
Motor pathways or the pyramidal pathwaysinclude two
components: the pyramidal tract or corticospinal tract and the
corticonuclear fibers. In function, the pyramidal tract controls muscle
of the trunk, the corticonuclear fibers control muscles of the head,
face and neck.
The pyramidal tract
The origins and pathways of the pyramidal tract are fully decribed
in the anatomy books, we would not repeat it. In general, the
pyramidal tract can be divided into two parts:Upper part (hemisphere
part) shaped like a fan and lower part (from cerebral stem
downwards) is cylinder in shape. At present, with the DTI we can see
the image of pyramidal tract from the cerebral cortex to the upper
part of the medulla oblongata.The pyramidal tract is composed of
approximately 1 million axons of motor neuron.
Each neuron consists of a cell body, one or more dendrites and an
axon. The axon is the primary structure part of the tract. Axons with
myelin sheath are called myelinated appear white, masses of such
axons form the fiber bundle. CNS axons are myelinate by oligo-
dendrocytes, which do not provide a neurilemma. Consequently,
damaged CNS axon (the pyramidal tract) usually do not regenerate to
result Waller degeneration.
1.2. Pathology
1.2.1. Cerebral infarction
Acute stage: The necrosis process is formed, local edema of the
brain, initiation is intracellular cytotoxic edemathen there were
vasogenic edema and extracellularedema.
Subacute stage: In this stage, the process of repair and absorption
of necrotic tissue, it takes place from the periphery towards the
center of encephalomalacic area. The result of this process is the
formation of cyst with surrouding glial scars.
Chronic stage: The appearance of the fluid-filled cavity lined by
astrocystes and glial scars, the sulci and ventricle is dilated, the gyri
is shrinked.