Pathophysiology of cerebral hypoxia and stroke

1. 2017-3-30
ChapterChapter :8:8
CerberalCerberal HypoxiaHypoxia &&
StrokeStroke
•• Presented by: Prof.Mirza Anwar BaigPresented by: Prof.Mirza Anwar Baig
•• Anjuman-I-Islam's Kalsekar Technical CampusAnjuman-I-Islam's Kalsekar Technical Campus
•• School of Pharmacy,New Pavel,NaviSchool of Pharmacy,New Pavel,Navi
Mumbai,MaharashtraMumbai,Maharashtra
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2. Etiology
1. Disturbances in auto regulation of
blood supply to the brain
2. Conditions affecting cerebral blood
vessels

3. 1. Disturbances in auto regulation of
blood supply to the brain
• Auto regulations fails at 60 mmHg
blood pressure.
• If sustained for few seconds leads to
irreversible brain damage.
• The neurons are affecting first, then
neuroglia cells and later than meninges
and blood vessels.

4. Conditions contd:
• Cardiorespiratory arrest
• Sudden severe hypotension
• Carbon monoxide poisoning
• Hypercapnia
• Drug over dosage with opioid
analgesics,

5. 2. Conditions affecting cerebral blood vessels
i. Occlusion of cerebral artery
ii. Arterial stenosis(narrowing of avortic
valve) occurs in arteritis
iii. If the individual survives the initial
episode of ischemia then infarction,
necrosis and loss of function of the
affected area of brain may occur

6. Stroke
(cerebrovascular disease)

7. Predisposing factors
•Hypertension
•Atheroma
•Cigarette smoking
•Diabetes mellitus
•It occurs when blood flow to brain is
suddenly intruppted causing hypoxia
•Effects are- paralysis, distrubences in
vision, speech

8. Causes are-
1.Cerebral infarction (85%): atheroma or thrombosis
•Transient ischemic attack (TIA)
•Recurrence attack may follow permanent damage
2. Spontaneous intracranial haemorrhage (15 %):
i. Intracerebral haemorrhage: mircroaneurysm in prolonged
hypertension,
A. severe haemorrhage: causes destruction and compression of
tissue sudden increase in ICP. Death due to damage in vital
centres of MO.
B. Less severe haemorrhage: causes paralysis and disorganized
speech and vision may be reversed after normal ICP
ii. Subarachnoid haemorrhage :
Aneurysm In subarachnoid space, associated with hypertension, blood
may spread around brain and spinal cord causing incrasese in
ICP but no brain damage