BRAIN INJURIES

The brain may be injured:

• By direct intrusion, either by a foreign object such as a penetrating weapon, bullet

)

• By deformation of the brain in closed head injuries )

(direct&indirect)

Mechanism of indirect brain damage

• The mechanism is mainly:

1- acceleration deceleration

2- rotational movement shearing strain)

Coup & contrecoup injury

3-The pressure gradient theory.

TYPES OF BRAIN INJURIES

A- concussion:

B- brain contusion

C- brain laceration

D- brain edema

E- difuse axonal injury

A-Brain concussion

It is a state of sudden transient loss

of consciousness following head

injuries. It is characterised by

momentary physiological disruption of

the function of the brain with little or

no noticeable anatomical

changes.(shaking of the brain)* Fate of concussion

1- Complete uncomplicated

recovery

2- compression

3- death

B- brain contusion

C- brain laceration

Both contusion and laceration can occur in

cases of coup or contre-coup lesion.

Occure in the outer layers .in the frontal &temporal lobes

D- cerebral edema

- Increased brain size&weight

- flattining of gyri&disappearance of sulci

- pallor of the brain

-Signs of herniation &shifting

- difficulty in the differentiation between

grey&white matter

- slicing the brain show wet cut surface&fluid

oozing

Brain edema

Practical notes

There may be no coup damage at all, only contrecoup.

May be no fracture of skull, even in the presence of severe coup and contrecouplesions.

The most common site for contrecoup injury is in the frontal lobes .It is often at the tips of the frontal poles and may be symmetrical, if a fall on the occiput has occurred.

Notes…..cont.

In a temporal impact, the contrecoup damage

may be not be on the contralateral

hemisphere, but on the opposite side of the

ipsilateral hemisphere from impact against the

falx cerebri.

The degree of contrecoup damage may be

severe,more than coup , especially in the frontal

lobes and tips of the temporal lobes.

Sequelae of Head Injuries:

1- Retrograde amnesia:

Loss of memory concerning the accident itself and for sometimes before the accident (partial amnesia).

2- Post-traumatic automatism:

The patient may do voluntary acts after the accident or even commits a crime. But he forgets every thing about what he did.

3- Post traumatic neurosis:

The patient may complain of some vague symptoms as headache, anxiety and insomnia. Sometimes all of these symptoms disappear after the victim receives the financial compensation.

4- Pos traumatic epilepsy:

Due to adhesion between the site of the trauma and the meninges.

5- Sepsis: meningitis, brain abscess and sinus thrombosis.

Causes of death in head injuries:

1. Rapid death: concussion, compression and

brain laceration

2. Delayed death:

Infections: e.g. meningitis, brain abscess and

sinus thrombosis.

Indirectly from epilepsy

-- -

1- hyperflexion

2- hyperextension

(whiplash injury)

3- compression

--

-

-

-

-

-

-

-

-

Cut throut

-

-

-

-

-

-

-

Haemothorax

Pneumothorax

Empyema

traumatic

(Whiplash injuiry)

spontaneous

Ruptured Acute MI -

Ruptured cardiac aneurysme-

Fatty degenaration

-

-

-

-

(Du,typhoid,TB -

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-