The most common type of
injury we see in emergency department. We treat patients with various degree of head
injury. Most commonly we see simple falls in paediatric patients who requires only
observation for a period of time.
The most common cause
of head injury is road traffic accident, falls and assaults followed by sports
related injuries and penetrating injuries.
Our brain is an
amazingly sensitive structure. It is
anatomically placed in a cushion of tissue to prevent damage from certain
velocity of impact. When the force
disrupts these layers, the impact reaches the brain tissue. Normal cerebral blood flow necessary for a
100g of brain tissue is 55ml for a minute.
Any decrease in this blood flow could cause significant injury to brain
tissue.
When there is an injury
to head, our brain has some mechanism to adopt itself to sudden changes. During an injury, any increase in the normal
mass of the brain could cause increase in pressure in the brain. The brain
compensates it by displacing the cerebrospinal fluid and venous blood out of
the cavity. When there is an additional increase to the mass, the brain loses
its capability to adopt and results in increase intracranial pressure, brain
herniation and quick fall in patient’s consciousness.
Classification
of Head injury:
Classification of Head
Injury is based on different factors.
Primary: Injury to brain occurring at the time of
impact. This damage includes any injury to brain tissue.
Secondary: Injury to brain tissue following a trauma
after certain period time could be a result of decreased oxygen to brain,
decreased blood pressure, increased intracranial pressure, low cerebral perfusion
pressure, pyrexia, seizures and metabolic
disturbances.
It can also be
classified according the severity of injury and it is determined by the
Glasgow coma scale.
Minor head injury: GCS
15 with no loss of consciousness.
Mild head injury: GCS
14 or 15 with Loss of consciousness
Moderate head injury:
GCS 9-13
Severe Head Injury: GCS
3-8
According
to the force of injury
Blunt
Penetrating
The effect of an injury is usually based on the
mechanism of injury. As a doctor we
could identify the nature of the impact the patient has had with just considering
the following questions:
1. Mechanism
of Injury
2. Loss
of consciousness
3. Level
of consciousness at scene and on transfer
4. Seizure
5. Probable
hypoxia or hypotension
6. Pre
existing medical condition
7. Medications
8. Illicit
drugs and alcohol.
For example, a person
is brought in to the hospital after a fall from a height or after a high impact
accident where the other person involved in the accidents GCS is still low.
Here you would expect a multiple injuries.
How do we begin to
examine a person with head injury?
It is always easy to
resuscitate a patient if we follow the principles of
ABCDE
A-AIRWAY
B-BREATHING
C-CIRCULATION
D-DISABILITY
E-EXPOSURE
We perform a primary
survey which itself is assessing ABCDE and then a secondary survey which
includes head to toe survey looking for any signs of injury. We should assess GCS which includes eye
response, verbal response and motor response.
The pupilary size is an
excellent mirror of the occulomotor nerve. Any change in size or any variation
of light response suggests a dysfunction of the third nerve.
Management of Head
Injury:
1.
Mild
Head injury:
When there is no
significant impairment in patient’s health and the GCS has always been 15/15,
then the patient can be discharged home after a period of observation.
In certain condition,
patient’s age and other medical condition may play important factors. In that
case we might need a CT scan. It is unnecessary to scan everyone that not to
miss any intracranial hematomas.
NICE
GUIDELINES FOR CT SCAN IN HEAD INJURY:
GCS <13 AT ANY POINT
GCS 12 OR 14 AT 2HOURS
FOCAL NEUROLOGICAL
DEFICIT
SUSPECTED OPEN,
DEPRESSSED OR BASAL SKULL FRACTURE
SEIZURE
VOMITING >ONE
EPISODE
URGENT
CT SCAN IF NONE OF THE ABOVE
AGE >65
COAGULOPATHY
DANGEROUS MECHANISM OF
INJURY (CT WITHIN 8HOURS)
ANTEGRADE AMNESIA
>30MIN
2.
Moderate to severe Head injury:
The main aim of
resuscitation of severe head injury is to prevent any secondary brain injury,
so it is important to maintain normal oxygen supply to brain and the blood
pressure. CT scan should be done and
intracranial hematomas should be reduced which will decrease the pressure in
the brain. If any hematomas found, then
we always discuss it with the neurosurgery specialists.
WHAT TYPE OF HEAD
INJURY REQUIRES SURGICAL MANAGEMENT?
1. EXTRADURAL
HEMATOMA:
It occurs between the skull and the
duramater. It is commonly seen in young male patients. The hematomas usually occur after the tear of
meningeal artery and a mass forms in between the skull and duramater.
It usually causes
secondary brain injury. Immediately
after the injury, patients complain of headache, but there will be no focal
neurological deficit, but after minutes or hours patient starts to deteriorate.
Early recognition and treatment is vital in case of extradural hematoma. Immediate evacuation of the mass is
significant for a better prognosis of patient’s condition.
2. ACUTE
SUBDURAL HEMATOMA:
It occurs between
duramater and arachnoid. As it involves
the layer nearer to the brain tissue, we would expect some degree of damage to
the brain and blood supply. It causes significant primary brain injury. Patients with acute subdural hematoma have
impaired level of consciousness from time of injury. Treatment is usually evacuation via a
craniotomy.
3. SUBARACHNOID
HAEMORRHAGE:
Aneurysms are the most
common cause of subarachnoid haemorrhage. Traumatic subarachnoid haemorrhage is
managed conservatively.
4. CHRONIC
SUBDURAL HEMATOMA:
It is usually seen in
elderly, particularly in patients on blood thinners. There is usually a history of trauma but
sometimes it occur without one. It can
present with headaches, cognitive impairment, focal neurological deficit and
seizures. Treatment is usually
evacuation of the mass via a burr hole.
5. CEREBRAL CONTUSION:
It occurs when the brain tissue
has an impact against skull either at the point of impact or on the other side
of the head. It is usually bruising to
the brain tissue which involves micro haemorrhages. A patient with cerebral contusion requires
observation for a period of time and in rare cases might need surgical
evacuation.
If you have anyone you
know has had a head injury and you think they are acting strangely or
complaints of severe headache, discomfort to light, vomiting or drowsy, then it is time for them to be taken to the
hospital immediately.
In elderly and children
with a head injury, it would be sensible to get it checked by your general
practitioner or at the nearest hospital.