Basic Anatomy & Pathophysiology of ischemic stroke

Basic discussion on Pathophysiology of Ischemic stroke

1. Ischemic Stroke: Basic
Anatomy and Pathophysiology
Dr. Ajay Kumar Agarwalla
Phase- A Resident (Neurology)
Blue Unit, Neurology dept. ,
BSMMU

2. Road Map
•Artery supply of the brain
•Findings associated with occlusion
•Key features of cerebral blood flow
•Auto regulation of cerebral blood flow
•Pathophysiology of infarction in brain
•Factors influence ischemic stroke

3. Arterial supply of the Brain

4. Anterior Cerebral Artery Occlusion
Contralateral hemiparesis and hemisensory loss involving mainly the
leg and foot (paracentral lobule of cortex)
Inability to identify objects correctly, apathy, and personality changes
(frontal and parietal lobes)

5. Contralateral hemiparesis and
hemisensory loss involving
mainly the face and arm
(precentral and postcentral
gyri)
Aphasia if the left hemisphere
is affected (rarely if the right
hemisphere is affected)
Contralateral homonymous
hemianopia (damage to the
optic radiation)
Middle Cerebral Artery
Occlusion

6. Contralateral homonymous
hemianopia with some
degree of macular sparing
(damage to the calcarine
cortex)
Visual agnosia (ischemia of
the left occipital lobe)
Impairment of memory
(damage of medial aspect
of the temporal lobe)
Posterior Cerebral Artery
Occlusion

7. Key features of blood flow in
BRAIN
• In an adult, CBF is typically
750 ml/min or
45-50ml/100g/min or
15 % of the cardiac output (CO)
In normal individuals, CBF remains constant when
the mean arterial pressure varies between
“60 and 160 mmHg”

8. Ideal Cerebral Auto regulationIdeal Cerebral Auto regulation
Lassen NA. Physiol Rev. 1959;39:183-238
Strandgaard S, Paulson OB. Stroke.1984;15:413-416

9. Matter of Concern
Cerebral Blood Flow (CBF) :
•Less than 23ml/100g/min, physiological
electrical function of the cell begins to fail-
“ischemic penumbra”.
•Below 10 ml/100g/min, ionic membrane
transport failure, Irreversible cell death- which
leads to- “infarction”.

11. Factors Influence Ischemic Stroke
•Rate and onset of duration
•Collateral circulation
•Systemic circulation
•Hypercoagulable states
•Increased temperature
•Hyper/hypo glycemia

12. Reference
Snells Clinical Neuroanatomy, 7
th
edition
Davidson’s Principles and Practice of Medicine, 22
nd

edition
Harrison’s Principles of Internal Medicine, 19
th
edition

http://what-when-how.com/neuroscience/blood-supply-of-the-central-nervous-system-gross-anatomy-of-the-brain-part-2/
http://en.wikipedia.org/wiki/Cerebral_blood_flow
Stroke Pathophysiology Sid Shah, MD