Abstract
The clinical examination is an important part of any patient consultation. After the primary survey and history-taking, a more in-depth examination of the patient is sometimes required to aid the working diagnosis and help negate other differential diagnoses. The extent of this depends on the stability of the patient and it may not be possible in time-critical circumstances. However, it is becoming an increasing part of paramedic practice owing to the continued expansion of the scope of the paramedic role in both urgent and emergency care. Educational delivery of clinical examinations of each of the main body systems is now an integral part of undergraduate paramedic curricula.
This clinical examination series provides a step-by-step overview for each of the main body systems. Continuing professional development (CPD) is an essential requirement for all clinicians in order to maintain and demonstrate currency and advancement within their roles. This series therefore provides an overview of each examination to support students, newly qualified paramedics and paramedics wishing to use these as a CPD development activity and an aide-memoire for clinical practice. These articles provide overviews of initial examination considerations, including first impressions.
In this month's edition, cranial nerves VII–XII will be explored.
How to use these guides
The articles in this series, which can be torn out for use in practice, are intended to support clinician development and to assist in the overall assessment of patient presentations. The information should be used to aid consideration of differential diagnoses in situations where life-threatening conditions have been ruled out.
The extent and explanation of each examination will not be to the depth of those provided in core literature texts, so further reading and consolidation are advised to support understanding, supplemental to these articles. Key questions will be included for reader consideration and to direct further study.
Most examinations are taught in a rigid format. However, in clinical practice, practitioners need to be flexible and adapt their approach dependent on the presenting condition and circumstance. While there is no single set way for each of these examinations, a good structure will reduce omissions and errors, and support the gathering of information to inform patient care.
Contemporary texts will provide the underpinning reference sources throughout this series, as many of the examination processes and techniques are universally applied, but differences will be highlighted. Readers will be signposted to these key texts for each clinical examination.
The series covers the following systems:
Cardiovascular system
Peripheral vascular system
Neurological system (upper and lower limbs)
Cranial nerves
Gastro-intestinal system
Respiratory system
Musculoskeletal system
Cranial nerves VII–XII
Following last month's article, which covered cranial nerves I–VI, cranial nerves VII–XII will be explored and their assessments detailed in this issue. The cranial nerve examination may form part of a wider neurological examination of a patient.
You may decide to complete only specific parts of an examination; for example, a patient complaining of acute hearing loss may require only an examination of their hearing. The level and depth of the assessment will depend on your patient's presenting complaint and physiological status.
Equipment required
512 Hz or 256 Hz tuning fork (if undertaking auditory tests)
Pen torch.
The ideal position of the patient is for them to be sitting opposite you with their eyes at the same level as yours.
VII: facial
This cranial nerve has both motor and sensory functions. It is responsible for the movement of the muscles involved with facial expressions, and its sensory element is responsible for taste, involving the anterior two-thirds of the tongue (Bickley and Szilagyi, 2017; Innes et al, 2018).
For the assessment of the facial expressions, Thomas and Monaghan (2014) and Swartz (2014) advise the examiner to demonstrate each movement for the patient to copy.
Initially, inspect for facial asymmetry with the patient relaxed, and also during initial conversation (Bickley and Szilagyi, 2017; Marieb and Hoehn, 2019). Minor facial asymmetry can be normal (Innes et al, 2018).
Ask the patient to raise their eyebrows as high as they can, with the examiner then gently pushing down (to assess the frontalis muscle), noting any weakness (Thomas and Monaghan, 2014). Throughout this, look for symmetrical wrinkling of the forehead (Innes et al, 2018)
Ask the patient to screw up their eyes. Then the examiner should try opening them, against gentle resistance (assessing the orbicularis oculi muscle) (Bickley and Szilagyi, 2017; Innes et al, 2018)
Ask the patient to smile and show their upper and lower teeth (to assess the orbicularis oris muscle) (Bickley and Szilagyi, 2017; Innes et al, 2018)
Ask the patient to puff out their cheeks (to assess the buccinator muscles) (Bickley and Szilagyi, 2017; Innes et al, 2018)
Weakness can be further tested by tapping the cheek and checking for continence of air.
Ask the patient about their sense of taste; aside from this, it is rarely tested routinely (Thomas and Monaghan, 2014).
REFLECTION
What is Bell's palsy and how does this differentiate from stroke?
VIII: vestibulocochlear
There are two branches of this nerve: the cochlear branch (responsible for hearing); and the vestibular branch (balance). The vestibular branch is not commonly assessed (Swartz, 2014). This cranial nerve has sensory functions and is sometimes referred to as the auditory nerve (Bickley and Szilagyi, 2017; Marieb and Hoehn, 2019).
Initially, ask the patient about any acute hearing impairments and inspect each ear (Thomas and Monaghan, 2014)
Standing behind the patient, whisper a word or number in each of the patient's ears in turn, then ask them to repeat what is said (Thomas and Monaghan, 2014; Lindridge, 2016)
Alternatively, make a noise in each ear in turn (e.g. rub fingers against thumb) and ask the patient to say when you stop (Lindridge, 2016)
Bickley and Szilagyi (2017) describe an alternate assessment which is a combination of the two methods above. The examiner whispers a number or word in one ear while rubbing their fingers together next to the opposing ear. The patient is then asked to repeat the word or number back.
You would not be expected to complete the following tests in the prehospital environment; however, it is useful to understand their significance.
Rinne's test
Tap and hold a tuning fork adjacent to one of the patient's ears, and say: ‘This is sound 1.’
Apply the base of the still vibrating tuning fork to the mastoid process, and say: ‘This is sound 2.’
Ask the patient which sound is louder. Then repeat for the other ear (Thomas and Monaghan, 2014; Innes et al, 2018).
Weber's Test
Tap and hold a tuning fork centrally against the forehead (Thomas and Monaghan, 2014; Innes et al, 2018).
Ask: ‘Does it sound louder on one side, or is it the same on both sides?’
Normally, Rinne's test is positive, i.e. air conduction (sound 1) will be louder than bone conduction (sound 2). Weber's test should find the sound to be perceived equally by both ears.
REFLECTION
What is neural deafness and conductive deafness, and how would these affect the outcomes of these two tests?
IX: glossopharyngeal; and X: vagus
These two nerves can be assessed together. They have both sensory, motor and autonomic functions, innervating parts of the tongue, the larynx and the pharynx (Thomas and Monaghan, 2014; Lindridge, 2016; Marieb and Hoehn, 2019). The motor portions of these nerves are involved in the movement of the larynx and pharynx during swallowing. The sensory portion detects touch, pressure, temperature and taste. The autonomic portion responds to changes in blood pressure and chemical changes in the blood (for example, oxygen and carbon dioxide levels) (Marieb and Hoehn, 2019).
Ask the patient to open their mouth. Inspect the soft palate and uvula with a pen torch. The uvula should be central in the midline
Ask the patient to say ‘aaah’. The uvula and soft palate should rise upwards, remaining in the midline and not deviating (Lindridge, 2016; Bickley and Szilagyi, 2017)
Ask the patient to cough and assess its strength (Thomas and Monaghan, 2014; Innes et al, 2018).
REFLECTION
What can cause the uvula to deviate, aside from lesions to cranial nerves IX and X?
The gag reflex is assessed to test these nerves; however, this is an unpleasant test, so may be omitted if no lesion is suspected (Thomas and Monaghan, 2014). This is also not routinely performed in the prehospital setting.
Speech involves nerves V, VII, IX, X and XII. Findings from the following tests can indicate a lesion on any of these nerves (Bickley and Szilagyi, 2017).
Test for speech impairment
Listen to the patient's speech, noting volume and clarity, listening for dysarthria and dysphonia (Bickley and Szilagyi, 2017; Innes et al, 2018)
Assess lingual (tongue) and labial (lip) sounds.
XI: accessory
Cranial nerve XI innervates the upper fibres of the trapezius and the sternocleidomastoid muscles, and has motor functions (Thomas and Monaghan, 2014).
Observe the patient's shoulders from behind, noting any atrophy, fasciculations and differences in symmetry (Swartz, 2014; Thomas and Monaghan, 2014; Bickley and Szilagyi, 2017)
Palpate both the trapezius and sternocleidomastoid for bulk (Innes et al, 2018)
Ask the patient to shrug their shoulders initially first and then using your hands on their shoulders to resist the movement (Swartz, 2014; Lindridge, 2016; Bickley and Szilagyi, 2017)
Ask the patient to turn their head to each side and resist the movement using your hand on their cheeks (Swartz, 2014; Lindridge, 2016; Bickley and Szilagyi, 2017).
Note any asymmetry.
XII: hypoglossal
The hypoglossal nerve has motor functions and innervates the tongue (Swartz, 2014).
Ask the patient to open their mouth
Inspect the tongue for wasting and fasciculations (Swartz, 2014)
Ask the patient to make their tongue protrude, looking for asymmetry, then ask them to move it from side to side (Lindridge, 2016)
Place your finger on the patient's cheek and ask them to push against it using their tongue (Thomas and Monaghan, 2014).
On completion of your examination, thank the patient and document your findings. Depending on patient presentation, further neurological assessment of the limbs may be considered. For each of the assessments for cranial nerves VII–XII discussed in this article, consider the causes of acute and chronic impairments and the clinical significance of these.
