Medical
Post-traumatic amnesia (PTA) & brain injury
A person coming out of a coma
doesn't just wake up, but goes through a gradual process of
regaining consciousness called post-traumatic amnesia.
When fully conscious, the brain is
constantly active - perceiving, processing and remembering
information. After a coma, it takes some time to reach full
consciousness again, and this period of post-traumatic amnesia can
last for hours, days or weeks. A mild concussion can also cause a
brief period of post-traumatic amnesia (PTA).
PTA is considered a stage in the brain's recovery process. Typical
effects include:
- disorientation and confusion about location, time and identity
of others
- Highly distractactable and disinhibited
- Difficulty with thinking, memory and concentration
- Anxiety, agitation and rapid changes in mood.
People with post-traumatic amnesia can
be partially or fully awake but they will be confused
and have difficulties with their short-term memory. If physically
able, they may wander, so it is important to make sure their
surroundings are free of any hazards.
There can be significant
behavioural changes can occur during this phase, where the patient
may be quiet and passive, or aggressive, abusive and agitated.
Patients usually have little or no awareness of these impairments
and will usually remember nothing of what happened later.
The assessment and rehabilitation process does not commence until
PTA is finished. The patient's memory is unable to retain
information which makes most rehabilitation techniques
ineffective.
What
the family can do
Any challenging behaviour is likely
due to the effects of the traumatic brain
injury and therefore should not be taken personally. In
most cases a person will usually not remember most, if any, of what
has happened during this time.
Too much stimulation during PTA can
lead to confusion and distress. The patient may be unable to cope
with noise and activity so ensure a peaceful quiet
environment.
Avoid overloading the person with
too much information at once when talking, and keep sentences
short. It is important to carefully watch for cues of discomfort
with levels of touch, noise, or activity.
The family needs to get enough sleep and 'time-out' from the
hospital to maintain their own health and energy levels. It is
normal for family members to feel they should not leave their loved
one alone in hospital, but you need to pace yourselves for the long
haul. Allowing time to rest will allow you to provide good support
during critical phases such as rehabilitation.
If sleep proves too difficult,
trying different relaxation techniques and make time to chat with
someone you trust and feel comfortable with.
Upon returning home, see if you
need to take precautions such as preventing the person from driving
and not leaving them alone in the house.
When
does PTA finish?
PTA usually is over when the
patient begins to retain information such as where they are, why
they are in hospital, and the month and year; in other words
continuous memory returns.
However, sometimes there can be
brief periods of orientation and good memory to it can take time to
ensure the PTA phase has finished. The good news is that signs of
orientation and memory ability are indicators that PTA may be
drawing to a close.
Following PTA, more assessments are conducted to gain further
insight into the nature and extent of injury, along with the
commencement of rehabilitation. Behavioural issues sometimes worsen
at this point as the patient becomes aware of what has happened to
them, and may have difficulty coping with the various emotions that
arise.
PTA as
a guide to recovery
Along with Glasgow Coma Score, the
length of PTA is often seen as one of the best measures of severity
of a traumatic brain injury or similar brain
disorder. This also means it can give a rough indication as to the
degree of recovery that can be expected.
In Australia the Westmead Post
Traumatic Amnesia Scale is the most widely used measure:
• PTA less than 5 minutes = "very
mild injury"
• PTA between 5-60 minutes = "mild injury"
• PTA between 1-24 hours = "moderate injury"
• PTA between 1-7 days = "severe injury"
• PTA greater than 7 days = "very severe injury".
References and further information
Marosszeky, N.E.V., Ryan, L.,
Shores, E.A., Batchelor, J. & Marosszeky, J.E. (1997). The PTA
Protocol: Guidelines for using the Westmead Post-Traumatic Amnesia
(PTA) Scale. Sydney: Wild & Wooley. Website:
http://www.psy.mq.edu.au/pta/page6.html
Headway UK. (2008). Post-Traumatic Amnesia-Fact Sheet. Retrieved
March 29, 2008, from
http://www.headway.org.uk/sitePages.asp?step=4&contentID=1334&navID=115
Wilson, B. A., Herbert, C. M., & Agnes, S. (2003). Behavioural
Approaches in Neuropsychological Rehabilitation: Optimising
Rehabilitation Procedures. New York, NY: Psychology Press.
Brain Injury Rehabilitation Unit (Sydney). (2006). Post-Traumatic
Amnesia. Retrieved March 29, 2008, from
http://www.swsahs.nsw.gov.au/biru/BIU%20Homepage/info/pta.asp
NSW Institute of Trauma and Injury Management. (2008). Post
Traumatic Amnesia (PTA). Retrieved March 29, 2008, from http://www.itim.nsw.gov.au/go/knowledge-base/clinical-resources/head-and-facial-injuries/
other-information-on-head-injuries/post-traumatic-amnesia-pta
Marosszeky, N.E.V., Ryan, L., Shores, E.A., Batchelor, J. &
Marosszeky, J.E. (1997). The PTAProtocol: Guidelines for using the
Westmead Post-Traumatic Amnesia (PTA) Scale. Sydney: Wild &
Wooley. Website: http://www.psy.mq.edu.au/pta/page6.html