Acquired Central Nervous System Vascular Disorders-1
Acquired Central Nervous System Vascular Disorders-1
Acquired Central Nervous System Vascular Disorders-1
A SEMINAR PRESENTED BY
DR.OFFIAH,SAU
ON THE
21ST DAY OF JUNE
2006.
OUTLINE:
• Introduction:
• Components of CNS
• Embryogenesis
• Arterial Circulation
• Vascular Disorders
• Vascular pathology
• Acquired CNS Vascular Disorder
• Non-Acquired CNS Vascular Disorder
• Classifications of Acquired CNS Vascular Disorders
• Traumatic
• Non-Traumatic
COMPONENTS OF CNS
EMBRYOGENESIS
• The human brain and spinal cord are ectodermal derivatives.
• The early embryologic portions of the developing brain are
the prosencephalon, mesencephalon, and rhombencephalon.
• The prosencephalon gives rise to the telencephalon, which
will become the two cerebral hemispheres, and the
diencephalon, which is composed mainly of thalamus and
hypothalamus.
• The mesencephalon becomes the midbrain.
• The rhombencephalon gives rise to the metencephalon,
which is composed of pons and cerebellum, and the
myelencephalon, which becomes the medulla oblongata.
• The spinal cord evolves from the remaining part of the
primitive neural tube.
CEREBRAL ARTERIAL
CIRCULATION
VASCULAR DISORDERS
• Vascular Pathology
• Blood vessels share many similarities with a water hose.
• Vascular pathology usually arises when there is:
• Abnormalities in the flowing blood (as seen in Embolization and
Thrombosis),
• Likeage due to breakdown of wall (as seen in Amyloid
Angiopathy, Trauma),
• Intraluminal Obstruction to blood flow (as seen in
Atherosclerosis),
• Extraluminal Obstruction to blood flow (as seen in Intracranial
Tumors) and
• When there is Ballooning of arterial wall (as seen in
Aneurysms).
• There is a supply and demand relationship between blood supply and
tissue metabolism
• Inadequate vascular supply or increased demand can both tip this
relationship.
• Inadequate vascular supply can be:
• Focal as seen in:
• Systemic as seen in:
• Hypotension
• Shock
• Pathologic increase in demand
• Inefficient use in fuel-mitochondrial disorder
• Inefficiency in using Oxygen-glycogen storage diseases
Acquired CNS Vascular Disorders
• Cerebrovascular diseases include some of
the most common and devastating
disorders.
• The incidence increases with age.
• Most cerebrovascular diseases are
manifest by the abrupt onset of a focal
neurologic deficit, as if the patient was
“struck by the hand of God”.
• This is defined clinically as stroke or transient
ischaemic attack depending on the duration of
neurologic deficit.
• Stroke is a clinical term that describes a
syndrome of rapidly evolving or sudden onset,
non-epileptic, neurologic deficit that lasts more
than 24 hours.
• Thus laboratory studies including brain imaging
are used to support the clinical diagnosis.
A case study
• A 70 year old cocaine addict male was sitting on a
bar stool when he was noted to suddenly fall to the
floor. He was unable to arise and the paramedics
were called. When they arrived, he was able to
answer questions and he stated that he had a severe
headache. Upon arrival to the hospital the admitting
physical examination demonstrated a right
hemiparesis. The patient became increasingly
somnolent after admission.
• In spite of supportive care, the patient became
comatose and died two hours after admission.
WHAT ARE THE POSSIBILITIES?
• Haemorrhagic Stroke
• Intraparenchymal, intraventricular, and
subarachnoid haemorrhage are usually non-
traumatic.
Hypertensive Brain Haemorrhage
Complication of cocaine
Ruptured Intracranial Aneurysms
SUBARACHNOID HAEMORRHAGE
Ischaemic Stroke
Ischaemia
Mitochondrial
Glutamate Energy failure damage
release
Apoptosis
Ca2+ \Na+ influx
Glutamate
receptor Free radical
iNOS formation
Proteolysis
Cell Death
Focal ischaemia
• Hypercoagulable disorders
-Protein C deficiency
-Protein S deficiency
-Antithrombin III deficiency
-Polycythemia vera
-Systemic malignancy
-Disseminated intravascular coagulopathy
• Vasculitis
-Primary CNS vasculitis
-Systemic Vasculitis
-Meningitis
• Drugs
-Cocaine
-Amphetamine
Venous thrombosis and
infarction1
• Etiology
-Inherent coagulopathy
-Oral contraceptives
-Pregnancy
-Dehydration
-Nephrotic syndrome
Venous thrombosis and
infarction2
• Distribution
-Superior sagittal sinus
-Lateral sinus
-Straight sinus