Aims Of The Session

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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

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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.

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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

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Indications For Surgery

• Elevation of depressed skull fracture
• Evacuation of a haematoma
• Arrest of a cerebral bleed

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Anatomy - Bones Of The Skull

• Support and protect the brain
• Frontal
• Temporal
• Parietal
• Occipital

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The Coverings of the Brain

• Meninges three connective tissue membranes that
  cover the brain and spinal cord
• Dura mater - white fibrous tissue outer layer
• Arachnoid - delicate membranes middle layer
  contains cerebrospinal fluid
• Pia mater - inner layer contains blood vessels

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Major Parts Of The Brain

• Cerebrum
• Largest area of the brain
• Divided into left and right hemispheres
• Right cerebral hemisphere controls the left side
  of the body
• Left cerebral hemisphere controls the right side
  of the body
• Each hemisphere is divided into four lobes
  frontal, parietal, temporal, occipital

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Lobes Of The Brain

• Frontal Lobe
• associated with reasoning, planning, parts of
  speech, movement, emotions, and problem solving
• Parietal Lobe
• associated with movement, orientation,
  recognition, perception of stimuli
• Occipital Lobe
• associated with visual processing
• Temporal Lobe
• associated with perception and recognition of
  auditory stimuli, memory, and speech

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Major Parts Of The Brain

• Cerebellum
• Second largest part of the brain
• It is connected to the brain stem
• Helps provide smooth coordinated body movement

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Major Parts Of The Brain

• Brain Stem
• is responsible for basic vital life functions
  such as breathing, heartbeat, and blood pressure.
  
• Midbrain
• Pons
• Medulla oblongata

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Ventricles
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CSF And Ventricles

• Cerebrospinal fluid
• Clear watery substance made in the ventricles by
  the choroid plexus
• Cushions the brain and spinal cord
• It circulates through the ventricles and
  sub-arachnoid space

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Intra-cranial Pressure

• When intra-cranial pressure begins to rise, the
  bodys 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.

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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.

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Cushings Response

• The following three symptoms are known
  collectively as Cushing's response triad
• Hypertension.
• Bradycardia.
• Abnormal respiratory pattern.
• They indicate brainstem dysfunction and
  exhaustion of compliance (Hickey 1997a) without
  urgent intervention, patients are likely to die.

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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
• volume of brain (cerebral oedema) - injury
• infection
• hypoxia
• CSF (eg due to obstruction to drainage)
• haemorrhage (eg subarachnoid)
• tumour
• haematoma

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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

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Head Injuries

• The head is vulnerable to injury
• 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)
• Any layer may be damaged by
• Direct impact on the box (blow)
• Dropping the box (fall)
• Shaking the box (acceleration/deceleration)

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Head Injuries

• Skull fracture
• Simple
• Linear or hairline
• Depressed fracture fragments are driven inwards

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Head Injuries

• Intracranial haemorrhage
• 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

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Head Injuries

• Extradural haemorrhage
• 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

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Head Injuries

• Subdural haemorrhage
• 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

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Head Injuries

• Intracerebral haemorrhage
• 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.

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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.

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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.
• GCS 13-15 (Mild)
• GCS 9-12 (Moderate)
• GCS 3-8 (Severe)

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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.

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DECORTICATE

• Decorticate posturing is also called decorticate
  response, decorticate rigidity, flexor posturing

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DECEREBRATE

• Decerebrate posturing typically the head is
  arched back, the arms are extended by the sides,
  and the legs are extended

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Neurological Observations

• Assess conscious level
• Speech
• Mental state
• Eyes
• Can the patient see
• Is there an eye injury eye maybe closed
• Can the patient focus

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Neurological Assessment

• It is important to assess a patients
  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

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Patient A

• 21 yr Male Bicycle Trauma (no PMH)
• Cant open eyes
• Cant answer questions
• Doesnt respond to stimuli
• What is the GCS ?

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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 ?

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Neurological Observations

• Pupillary observations
• What is their size normal, moderately dilated
  or fully dilated
• What is the pupil reaction to light brisk,
  sluggish or fixed

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Neurological Observations

• Limb movement tone
• 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
• Is there any abnormal involuntary movement

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Neurological Observations

• Blood pressure
• Pulse
• Respiration
• Temperature

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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

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Any Questions?
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Bibliography

• Verran B, Aisbett P.(1988) Neurological and
  Neurosurgical Nursing. London Edward Arnold
  Publishing