leture

1. Head injury
Roman A. Hayda, MD
Original Author
March 2004; Revised July 2006, November 2010

2. Basic Anatomy
• Scalp
• Skull
• Meninges
– Dura Mater
– Arachnoid
– Pia Mater
• Brain Tissue
• CSF and Blood

3. Ventricles

4. Intracranial Volume
• 80% Brain Matter
• 10% Blood
• 10% CSF

5. The MONROE KELLIE doctrine

6. Normal state- ICP normal

7. Compensated state- ICP normal

8. Uncompensated state- ICP
Elevated
75 ml 75
ml

9. Intracranial Pressure
• The pressure of the brain contents within the skull is
intracranial pressure (ICP)
• The pressure of the blood flowing through the brain is
referred to as the cerebral perfusion pressure (CPP)
The pressure of the blood in the body is the mean arterial
pressure (MAP)
CEREBRAL BLOOD FLOW
Normal CBF = 50ml/100gm of brain/min
“AUTOREGULATIOn the mechinsm of maintaining
flow at different blood pressure

10. ROLE OF
INTRACRANIAL PRESSURE
• 10 mmHg - Normal
• > 20mmHg - Abnormal
• > 40mmHg - Severe
•  ICP  deteriorates brain function  poor outcome

11. Intracranial Pressure
• Cerebral Perfusion Pressure (CPP) can be determined by
the following formula:
CPP = MAP - ICP
• Normal CPP range is 60 - 150 for autoregulation to work
well

12. SYMPTOMS & SIGNS OF
INCREASED ICP
• decrease level of consciousness
• Headache, vomiting, seizures
• Cushing’s Triad – ‫كشنج‬ ‫ثالثية‬
 bradycardia
 hypertension
 abnormal respiration
• Pupillary changes
• Papilledema ‫العين‬ ‫شبكية‬ ‫تورم‬

13. • Primary Injury
• Mechanical irreversible damage - brain lacerations,
hemorrhages, contusions, and tissue avulsions,
• Microscopy - primary injury causes permanent
mechanical cellular disruption and microvascular injury.
PATHOPHYSIOLOGY

14. Secondary Injury
• Neurologic outcome after head trauma
- degree of secondary brain injury.
• Common Secondary systemic insults –
Hypotension – SBP < 90
Hypoxia - Po2 less than 60
Anemia – reduces O2 Carrying capacity of the blood, to the
injured brain tissue,
• Other causes - hypercarbia, hyperthermia, coagulopathy, and seizures.

15. CLASSIFICATION
head injury can be classified according to:
• morphology
• severity
• mechanism

16. MECHANISM
• BLUNT INJURY
 High Velocity
 Low Velocity
• PENETRATING INJURY
 Gunshot
 Sharp instruments

17. Severity -GLASGOW COMA SCALE
ASSESSMENT AREAS SCORE
Eye opening
Best Motor Response
Verbal Response
Total
4
6
5
15
Mild - GCS 13 - 15
Moderate - GCS 9 - 12
Severe - GCS 3 - 8

19. MORPHOLOGY
• SCALP INJURY
 Cephal Hematoma
 Subgaleal Hematoma

20. • SKULL FRACTURES
• Vault : linear/stellate
depressed/non depressed
open/closed

21. Basilar : with/with out CSF leak
with/with out seventh-nerve palsy
Battle sign Raccoon eyes
CSF rhinorrhea

22. INTRACRANIAL LESIONS
• Focal : Epidural hematoma
subdural hematoma
intracerebral hematoma

23. Epidural haematoma
• Collection of blood & clot above dura matter and below
bones of the skull
• Source Middle Meningeal Artery
Dural Venous Sinuses
• Clinical findings: Brief loss of consciousness, headache,
drowsiness, dizzy, nausea, vomitting
• Rapid clinical deterioration
• Talk & die

24. Epidural haematoma

25. • Subdural hematomas
• Most frequently from
tearing of a bridging vein
between the cerebral cortex
and a draining venous sinus.
• - acute - <24hrs
- subacute – 24hrs-2wks
- chronic - >2wks
SDH
Shape-
Crescent

26. Intra Cerebral Heamatoma
• Formed within brain tissue & caused by shearing or tensile
forces that mechanically stretch and tear deep small caliber
arterioles
• Most common in temporal and frontal regions
• C/F depend on site involved

27. INTRACRANIAL LESIONS
Diffuse : concussion
multiple contusion
hypoxic/ischemic injury

28. Concussion ‫المخ‬ ‫في‬ ‫ارتجاج‬
• Temporary & brief interruption of neurological function
after minor head injury
• Due to shearing / stretching of white matter fibres at the
time of impact or temporary neuronal dysfunction
• C/o headache, confusion, amnesia
• CT/MRI cannot detect