A Subdural haematoma is a collection of blood between the skull
and the brain. The brain is surrounded by three tough membranes or
dura. These membranes are called the meninges, the outermost
membrane is called the dura mater, then the arachnoid and then the
pia mater. The space between the two outer membranes (the dura
mater and arachnoid) is called the subdural space. If a blood
vessel within this space is damaged, blood can leak out and cause a
clot to form, this is called a sub-dural haematoma. Subdural
haematoma's are classed as chronic or acute based on the time
interval between injury and the onset of signs and symptoms.
They are often caused by trauma to the head or can be associated
with anti-coagulant (blood thinning) medication such as
Warfarin.
Symptoms
The skull is like a closed box and the brain fits very snugly
within this box. As the blood clot forms it takes up room squashing
the brain which in turn causes the pressure within the skull
(intracranial pressure) to increase. This increase in pressure can
affect the structure and function of the brain. Symptoms such as
drowsiness, headaches, confusion, limb weakness and visual problem
begin to show.
Types of subdural haematomas
There are different types of subdural haematomas, it is
important to note that the symptoms associated with all types are
all very similar:
Acute subdural - onset of symptoms usually
within 48 hours after injury.
Chronic subdural - symptoms can occur between
two weeks and several months after the initial injury. They are
most common in elderly people, this is because the brain shrinks as
we get older, causing greater free space between it and the skull,
therefore, it takes longer for the blood clot to squash the brain
and cause any symptoms. Because of the time lapse between the
initial trauma and the onset of symptoms there may be a delay in
diagnosis and it can often be difficult to relate it to an incident
which may have happened several weeks previously. The development
of a subdural haematoma in older people can also be related to the
use of anti-coagulant medication such as warfarin. If the clotting
function of the blood is unstable it can prevent a bleed from
clotting and thus cause a large clot to form.
Extra dural haematoma - This term refers to
bleeding between the inner skull and the dura mater (the outermost
layer of the three layers covering the brain). The cause is usually
head trauma, sufficient to tear blood vessels directly beneath the
skull. Symptoms are often more immediate after the trauma and the
deterioration rapid. Extra dural haematoma's are more common in
younger people, especially young men, this is because young men
tend to partake in more high risk activities than women.
Diagnosis and Treatment
Diagnosis is made based on clinical history and by a
computerised tomography scan (CT). If the subdural haematoma is
small and the symptoms are not severe it may be left to reabsorb by
itself with no surgical intervention. During this time the patient
would be carefully monitored for any deterioration.
If symptoms are severe, such as decreased level of
consciousness, confusion etc, surgical intervention may be
required. This can be done in two ways, either by a burr hole or
craniotomy.
Burr holes are holes drilled through the skull over the area of
the bleed which allow the haematoma to be 'sucked' out. The
procedure requires a small incision through the skin which is
closed by a few stitches or staples. Burr holes are less invasive
than a craniotomy and are often used for an acute subdural
haematomas as the blood tends to be more 'runny' before it has
clotted too much.
A craniotomy is a larger opening in the skull and allows greater
access to the brain. This method is more frequently used to remove
chronic subdural haematomas as over time the blood will have become
more solid and therefore is difficult to be 'sucked' out through a
burr hole.
Following both procedures the patient will be closely monitored
and regular neuro observations performed. The reason for this is to
check the person's conscious level, it involves the nurses shining
a light in the eyes, testing strength of arms and legs and also
asking simple questions such as name and age. From these
observations a Glasgow Coma Score (GCS) is recorded, any decrease
in this score may indicate that the clot was reforming or the brain
was being compromised in some way.
A patient who has a subdural haematoma is often nursed lying
flat, this aims to prevent the recollection of the blood which can
occasionally happen if the original site of rupture has not healed.
This can occur particularly in the case of elderly patients who
have sustained a chronic subdural haematoma. The patient may also
have a drip (intravenous fluids) to maintain hydration and will be
given pain killers for any headaches they may be experiencing.
Recovering from a subdural haematoma
Patients are often discharged home within a few days following
treatment, once their neurological observations are stable and the
doctors are confident there will be no further collection of the
blood clot.
Recovery is a very individual process and some people take
longer than others.
In cases where the haematoma has caused severe damage to the
brain the patient may need more intensive support, such as neuro
rehabilitation involving physiotherapists, occupational therapists
and speech therapists. Recovery following such a severe injury can
be a long process and can result in more permanent deficits, such
as limb weakness, personality changes, memory problems etc and
individuals may need long term care.
For further information on how MyInjuryLawyer can help with a
subdural haematoma claim, please call us free on 0800
043 4299.