The Royal Marsden Hospital Manual of Clinical Nursing Procedures - Lisa Dougherty [502]
Muscle tone
This involves flexing and extending the patient’s limbs on both sides and noting how well such movements are resisted. Increased resistance would denote increased muscle tone and vice versa.
Muscle coordination
Any disease or injury that involves the cerebellum or basal ganglia will affect coordination. Assessment of hand and leg coordination can be achieved by testing the rapidity and rhythm of alternating movements and pointtopoint movements.
Reflexes
Amongst the most important reflexes are blink, gag and swallow, oculocephalic and plantar.
Blink: this is a protective reflex and can be affected by damage to the Vth cranial nerve (trigeminal) and the VIIth cranial nerve (facial). Absence of the corneal reflex (Vth and VIIth cranial nerves) may result in corneal damage. Facial weakness (VIIth cranial nerve) will affect eye closure.
Gag and swallow: damage to the IXth cranial nerve (glossopharyngeal) and Xth cranial nerve (vagus) may impair protective reflexes. These two cranial nerves are always assessed together as their functions overlap. Muscle innervation of the palate is from the vagus, while sensation is supplied by the glossopharyngeal nerves (Aucken and Crawford 1998, Fuller 2004).
Oculocephalic: this reflex is an eye movement that occurs only in patients with a severely decreased level of consciousness. In conscious patients this reflex is not present. When the reflex is present, the patient’s eyes will move in the opposite direction from the side to which the head is turned. However, in patients with absent brainstem reflexes, the eyes will appear to remain stationary in the centre. Assessing this reflex should not be carried out if there is suspected instability of the cervical spine as this reflex can involve head movement which could exacerbate any spinal injury (Aucken and Crawford 1998).
Plantar: abnormalities of plantar reflex will help to locate the anatomical site of the lesion. Upgoing plantar (extension) reflex is termed ‘positive Babinski’ and indicates an upper motor neurone lesion. It should be noted that in babies under 1 year of age upgoing plantar is normal (Aucken and Crawford 1998).
Abnormal movements
When carrying out neurological observations, any abnormal movements such as seizures, tics and tremors must be noted.
Sensory functions
Constant sensory input enables an individual to alter responses and behaviour to suit the environment. When disease or injury damages the sensory pathways, the sensory responses are always affected. Any assessment of sensory function should include an evaluation of the following.
Central and peripheral vision.
Hearing and ability to understand verbal communication.
Superficial sensations (light touch, pain) and deep sensations (muscle and joint pain, muscle and joint position).
(Carlson 2002a, Fuller 2004)
Visual acuity
The clarity or clearness of vision may be tested with a Snellen chart, which uses decreasing letter size, or newspaper prints, with and without glasses if worn.
Visual fields
Lesions at different points in the visual pathways affect vision (Table 12.11). It should be noted that loss of vision is always described with reference to the visual fields rather than the retinal fields (Weldon 1998).
Table 12.11 Visual pathways
Vital signs
It is recommended that assessments of vital signs should be made in the following order.
1. Respirations.
2. Temperature.
3. Blood pressure.
4. Pulse.
See relevant sections in this chapter.
Respirations
Of these four vital signs, respiratory patterns give the clearest indication of how the brain is functioning because the complex process of respiration is controlled by more than one area of the brain. Any disease or injury that affects these areas may produce respiratory changes. The rate, character and pattern of a patient’s respiration must be noted. Abnormal respiratory patterns are listed in Table 12.12.
Table 12.12 Abnormal respiratory patterns