Transcript Neurological Observations

Aims Of The Session
To gain knowledge and understanding of
the anatomy of the brain
To gain knowledge and understanding
about head injuries
To gain knowledge and understanding of
neurological assessment and the skills
involved in assessing patients
Introduction
Each year 1.4 million people in the UK
suffer head injury, 150,000 will be
admitted to hospital with most being
discharged within 48 hours.
Indications For Admission
Patients who are unwell or who have a risk of
later deterioration from an intracranial
haematoma
Patients who have lost consciousness or who
have suffered amnesia of more than 5 min
Presence of abnormal neurological findings
Skull fractures
Indications For Surgery
Elevation of depressed skull fracture
Evacuation of a haematoma
Arrest of a cerebral bleed
Anatomy - Bones Of The Skull
Support and protect
the brain
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Frontal
Temporal
Parietal
Occipital
The Coverings of the Brain
Meninges: three
connective tissue
membranes that cover
the brain and spinal cord
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Dura mater - white fibrous
tissue: outer layer
Arachnoid - delicate
membranes: middle layer
contains cerebrospinal fluid
Pia mater - inner layer
contains blood vessels
Major Parts Of The Brain
Cerebrum
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Largest area of the brain
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Divided into left and right
hemispheres
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Right cerebral hemisphere
controls the left side of the
body
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Left cerebral hemisphere
controls the right side of the
body
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Each hemisphere is divided
into four lobes – frontal,
parietal, temporal, occipital
Lobes Of The Brain
Frontal Lobe
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associated with reasoning,
planning, parts of speech,
movement, emotions, and
problem solving
Parietal Lobe
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associated with movement,
orientation, recognition,
perception of stimuli
Occipital Lobe
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associated with visual
processing
Temporal Lobe
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associated with perception and
recognition of auditory stimuli,
memory, and speech
Major Parts Of The Brain
Cerebellum
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Second largest part of
the brain
It is connected to the
brain stem
Helps provide smooth
coordinated body
movement
Major Parts Of The Brain
Brain Stem
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is responsible for basic
vital life functions such
as breathing,
heartbeat, and blood
pressure.
Midbrain
Pons
Medulla oblongata
Ventricles
CSF And Ventricles
Cerebrospinal fluid
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Clear watery
substance made in the
ventricles by the
choroid plexus
Cushions the brain
and spinal cord
It circulates through
the ventricles and subarachnoid space
Intra-cranial Pressure
When intra-cranial pressure begins to rise, the
body’s own compensatory mechanisms include
decreasing the production of CSF and restricting
the blood flow to the brain (by vasoconstriction).
Once the capacity of these compensatory
mechanisms is exceeded, the intra-cranial
pressure can continue to rise.
In addition, as intra-cranial pressure rises, the
cerebral blood vessels are constricted, reducing
blood flow further.
Intra-cranial Pressure
Normal intracranial pressure (ICP), usually
measured as a mean pressure, is often
cited as 0-10mmHg
Sustained high pressures can cause
'coning' (tentorial herniation), when
brainstem tissue is forced through the
foramen magnum into the spinal cord.
Cushing’s Response
The following three symptoms are known
collectively as Cushing's response triad
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Hypertension.
Bradycardia.
Abnormal respiratory pattern.
They indicate brainstem dysfunction and
exhaustion of compliance (Hickey 1997a);
without urgent intervention, patients are likely to
die.
Causes Of Raised Intra-Cranial
Pressure
Anything that increases the volume of brain
tissue, blood or CSF within the skull will raise
intra-cranial pressure:
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volume of brain (cerebral oedema): - injury
infection
hypoxia
CSF (eg due to obstruction to drainage)
haemorrhage (eg subarachnoid)
tumour
haematoma
Head Injuries
Head injury is most likely to happen to young
men, with an average age of 30 who are
involved in road traffic accidents
Other causes of adult injuries include contact
sports, such as rugby and boxing
Children often suffer head injury from bicycle
accidents or pedestrian-vehicle collisions and
very young children and old adults can suffer
injury from falls
Head Injuries
The head is vulnerable to injury
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Analogy for a head injury
Blancmange (brain)
Wrapped in cling film (arachnoid mater)
In a paper bag (dura mater)
Inside a cardboard box (skull)
Wrapped in brown paper (skin)
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Any layer may be damaged by
Direct impact on the box (blow)
Dropping the box (fall)
Shaking the box (acceleration/deceleration)
Head Injuries
Skull fracture
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Simple:
Linear or hairline
Depressed fracture –
fragments are driven
inwards
Head Injuries
Intracranial haemorrhage
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The dura and arachnoid membranes and their
associated blood vessels are readily torn by impact or
fractured bone fragments
There are four types of intracranial haemorrhages
Extradural
Subdural
Subarachnoid
Intracerebral
Head Injuries
Extradural haemorrhage
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Results from rupture of one
of the meningeal arteries
that run between the dura
and the skull.
The middle meningeal
artery is most commonly
affected.
Usual cause is a skull
fracture
Head Injuries
Subdural haemorrhage
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More common than
extradural haemorrage
Associated with sudden
jarring or rotation of the
head
Shears and tears the small
veins which bridge the gap
between the dura and
cortical surface of the brain
Head Injuries
Intracerebral haemorrhage:
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May be natural, due to spontaneous rupture
of a small blood vessel which has been
weakened by the effects long-standing high
blood pressure.
Traumatic due to extension of haemorrhage
from surface contusions deep into the
substance of the brain.
Assessment Of Head Injuries
Glasgow Coma Scale (GCS)
Scoring system originally described for
patients with head injury; now applied to
other causes of coma
The Glasgow coma scale (GCS) is a
reliable and universally comparable way of
recording the conscious state of a person.
Assessment Of Head Injuries
Three types of response are measured,
and added together to give an overall
score.
The lower the score the lower the patient's
conscious state.
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GCS 13-15 (Mild)
GCS 9-12 (Moderate)
GCS 3-8 (Severe)
Eye Opening
E
spontaneous
4
to speech
3
to pain
2
no response
1
Best Motor Response
M
To Verbal Command:
obeys
6
To Painful Stimulus:
localizes pain
5
flexion-withdrawal
4
flexion-abnormal
3
extension
2
no response
1
Best Verbal Response
V
oriented and converses
5
disoriented and converses
4
inappropriate words
3
incomprehensible sounds
2
no response
1
E + M + V = 3 to 15
•8 is the critical score
•Less than or equal to 8 at 6 hours 50% die
•9-11 = moderate severity
•Greater than or equal to 12 =
minor injury
Coma is defined as:
(1) not opening eyes,
(2) not obeying commands
(3) not uttering understandable
words.
DECORTICATE
Decorticate posturing is also called
decorticate response, decorticate
rigidity, flexor posturing
DECEREBRATE
Decerebrate posturing :typically the head
is arched back, the arms are extended by
the sides, and the legs are extended
Neurological Observations
Assess conscious level
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Speech
Mental state
Eyes
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Can the patient see
Is there an eye injury – eye maybe closed
Can the patient focus
Neurological Assessment
It is important to assess a patient’s neurological
state if a patient has a head injury, in a coma or
have had neuro surgery performed
This assessment can indicate quite quickly a
need for intervention
Neurological assessment may be carried out
every fifteen minutes or half hourly depending
on the condition of the patient
The most serious situation is the deterioration of
conscious level due to raised intracranial
pressure
Patient A
21 yr Male Bicycle Trauma (no PMH)
Can’t open eyes
Can’t answer questions
Doesn’t respond to stimuli
What is the GCS ?
Patient B
52 Female (2 week history of headache)
Responds to verbal commands
Responds to questions is coherent but
confused
Localises to pain (moves hand away from
site)
What is the GCS ?
Neurological Observations
Pupillary observations
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What is their size – normal, moderately
dilated or fully dilated
What is the pupil reaction to light – brisk,
sluggish or fixed
Neurological Observations
Limb movement & tone
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Can the patient move their limbs on command
Movement is it normal, weak, severely weak or
absent
If absent does the patient respond to painful stimuli
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Is there any abnormal involuntary movement
Neurological Observations
Blood pressure
Pulse
Respiration
Temperature
Signs Of Raised ICP
Headache
Vomiting
Increasing
drowsiness
Deterioration in
mental and verbal
response
Inequality of the
pupils with sluggish
reaction to light
Development of
hemiparesis
Incontinence
Pulse rate becomes
slower
Blood pressure rises
Respiration – depth,
rate and rhythm
change when patient
loses consciousness
Any Questions?
Bibliography
Verran B, Aisbett P.(1988) Neurological
and Neurosurgical Nursing. London
Edward Arnold Publishing