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Neurological Assessment and Monitoring 433

upper arm near the axilla are methods for introducing ● pinpoint non-reactive pupils are associated with
central pain. Hand grasp is a reflex and is a poor test for opiate overdose
motor strength. If the patient does not respond to verbal ● non-reactive pupils may also be caused by local
stimulus but moves spontaneously in a purposeful damage
manner (picks at linen, pulls at tubes), the patient is ● atropine will cause dilated pupils
localising. Painful stimulus is not required if spontane- ● one dilated or fixed pupil may be indicative of an
ous localisation has been observed. Watch for symmetry. expanding or developing intracranial lesion, com-
Localising is purposeful and intentional movement pressing the oculomotor nerve on the same side of the
intended to eliminate a noxious stimulus, whereas with- brain as the affected pupil
drawal is a ‘smaller’ movement used to ‘get away from’ ● A sluggish pupil may be difficult to distinguish from
noxious stimulus. Abnormal flexion differs from with- a fixed pupil and may be an early focal sign
drawal in that the flexion is rigid and abnormal looking. of an expanding intracranial lesion and raised intra-
Abnormal extension is a rigid movement with extension cranial pressure. A sluggish response to light in a
of the limbs. previously reacting pupil must be reported
immediately.
Assessment of awareness Assessment of pupillary function focuses on three areas:
If arousable, progress to assessment of awareness using (1) estimation of pupil size and shape; (2) evaluation of
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the Glasgow Coma Scale (GCS). Teasdale and Jennett pupillary reaction to light; and (3) assessment of eye
designed the GCS to establish an objective, quantifiable movements. Metabolic disturbances rarely cause pupil-
measure to describe the prognosis of a patient with a lary changes, so abnormal pupillary findings are usually
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brain injury and include scoring of separate subscales due to a nervous system lesion. Irregular-sized pupils
related to eye opening, verbal response and motor are normal for some people and eye prostheses are
response (Table 16.7). Originally, the GCS was developed common so it is important to establish and document
as three separate response areas and reported as such. these findings so a trend can be established to determine
Contemporary use of the GCS automatically adds the normal from altered states.
three best response scores and easily loses the informa-
tion given from the separate response areas. Reporting the Eye and eyelid movements
GCS as three numbers and then the total gives a broader Patients who are comatose will exhibit no eye opening.
assessment interpretation.
In patients with bilateral thalamic damage, there may be
The advantage of the GCS is that it allows rapid serial normal consciousness, but an eye opening apraxia may
comparisons and categorisation of basic neurological mimic coma. If the patient’s eyes are closed, the clinician
function over time. However, it has several recognised should gently raise and release the eyelids. Brisk opening
weaknesses, including poor prediction of outcome and closing of the eyes indicates that the pons is grossly
beyond survival, poor interrater reliability, and inconsis- intact. If the pons is impaired, one or both eyelids may
tent use in the prehospital and hospital settings. GCS close slowly or not at all. In the patient with intact frontal
accuracy will be affected if the patient is receiving anaes- lobe and brainstem functioning, the eyes, when opened,
thetic agents or sedation and noxious stimuli should be should be pointed straight ahead and at equal height. If
avoided. Furthermore, the rare event of a locked-in syn- there is awareness, the patient should look towards
drome where a patient is neurologically aware and awake stimuli after eye opening. Eye deviation indicates either
but not responding is poorly represented by the GCS. a unilateral cerebral or brainstem lesion. If the eyes
Also, interpretation of response in regard to language deviate laterally, gently turn the head to see if the eyes
used or a previous communication disability is important will cross the midline to the other side. A pattern of
for assessment accuracy. See Online resources for a link to spontaneous, slow and random movements (usually lat-
a full GCS procedure. erally) is termed roving-eye movements. This indicates
that the brainstem oculomotor control is intact but
awareness is significantly impaired. 31
Eye and pupil assessment
Pupillary responses, including pupil size and reaction Limb movement
to light, are important neurological observations and
localise cerebral disease to a specific area of the brain. Assessment of extremities and body movement (or motor
response) provides valuable information about the
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The immediate constriction of the pupil when light is patient with a decreased level of consciousness. The
shone into the eye is referred to as the direct light clinician must observe the patient’s spontaneous move-
reflex. Withdrawal of the light should produce an ments, muscle tone, and response to tactile stimuli.
immediate and brisk dilation of the pupil. Introduction Decorticate (flexor) posturing is seen when there is
of the light into one eye should cause a similar con- involvement of a cerebral hemisphere and the brain stem.
striction to occur in the other pupil (consensual light It is characterised by adduction of the shoulder and arm,
reaction). 28 elbow flexion, and pronation and flexion of the wrist
while the legs extend. In terms of the GCS motor score,
Other points to consider when conducting pupillary the withdrawal flexor scores a higher (4/6) than a spastic
observations include the following: 29 flexor movement (3/6). Decerebrate (extensor) posturing