Neurological Assessment and GCS

Symptoms of neurological changes often vary but may include sensory changes, motor changes, reflex changes, altered awareness and/or personality, altered level of consciousness and headaches (Koutoukidis et al. 2017).

Neurological observations collect data on a patient’s neurological status and can be used for many reasons, including in order to help with diagnosis, as a baseline observation, following a neurosurgical procedure, and following trauma (Mooney & Comerford 2003).

Therefore, it is important that all healthcare professionals are efficient and accurate in assessing the neurological status of their patients.

It is also important to remember that these changes may occur rapidly over a short period of time or more gradually, taking place over days or weeks. This is why accurate neurological assessments and observations are vital in ensuring the early recognition of neurological deterioration in patients (Koutoukidis et al. 2017; Mooney & Comerford 2003).

The Neurological Assessment

A neurological assessment involves checking the patient in the main areas in which changes are most likely to occur:

• Level of consciousness
• Pupillary reaction
• Motor function
• Sensory function
• Vital signs.

(QAS 2021a)

Glasgow Coma Scale (GCS)

There are many different assessment tools for neurological function, however, the most widely known and used tool is the Glasgow Coma Scale (GCS).

The patient is assessed and scored in three areas:

1. Eye opening
2. Verbal response
3. Motor response.

(QAS 2021b)

The highest possible score is 15, which reflects an individual who is fully alert, aware and orientated, whereas the lowest possible score is 3 and reflects an unconscious individual.

Although pupil reaction is not included as part of the GCS, it is often incorporated into the neurological assessment charts used in healthcare facilities in addition to the use of the GCS. Instead of pupillary reaction, the GCS focuses on whether the patient’s eyes are opening spontaneously or not (Majdan et al. 2015).

Because the GCS is widely known, it is a quick way to communicate a patient’s neurological status and provides a standardised assessment of their neurological functioning. However, there can be some inconstancies with its use.

In particular, there may be variations seen in the recording of pupil size as well as motor weakness between assessors. Therefore, it is important that nurses and health professionals are using the tool correctly to ensure these inconstancies do not affect patient care (Mooney & Comerford 2003; Reith et al. 2015).

Note that the best response should be recorded for each category (QAS 2021b).

(Teasdale 2015; Jain & Iverson 2020)

Assessing Level of Consciousness

An individual’s level of consciousness may deteriorate for a number of different reasons, including head injuries, increased intracranial pressure, haemorrhage, or lesions and tumours.

Determining a patient’s level of consciousness may be easy or difficult, depending on the individual you are assessing.

In some cases, the patient’s level of consciousness will be obvious when you are talking to them. However, sometimes you may find that they are not responding in an appropriate way or appear confused. Sometimes they may show no response at all.

Sound and pain are the most common stimuli used to assess a patient’s level of consciousness.

Sound can be used by speaking to the patient, whilst pain is usually reserved for patients with a decreased level of consciousness who are not responding when you are speaking to them (Koutoukidis et al. 2017; Mooney & Comerford 2003).

The use of painful stimuli is sometimes necessary in order to rouse a patient who has a decreased level of consciousness. The response of the patient to painful stimuli can be classed as:

• Purposeful: The individual pushes the assessor away, withdraws the affected body part or winces
• Non-purposeful: The application of the painful stimuli causes muscle contraction or the individual only moves the affected body part slightly
• Unresponsive: There is no response to the painful stimuli.

(Koutoukidis et al. 2017)

AVPU Assessment

A rapid assessment tool that is utilised in the healthcare field to measure conscious state is the AVPU scale.

• A stands for Alert

  The patient is aware of the environment and the examiner and is opening their eyes spontaneously. They can also follow commands and track objects.

• V stands for Verbal

  The patient’s eyes do not open spontaneously, rather, their eyes only open in response to a verbal stimuli directed towards them. The patient can respond to this verbal stimuli directly and in a meaningful way.

• P stands for Pain

  The patient's eyes do not open spontaneously or in response to verbal stimuli. The patient will respond to painful stimuli directed towards them by moving, moaning or crying out.

• U stands for Unresponsive

  The client is not responding spontaneously, or to verbal or painful stimuli.

(Romanelli & Farrell 2021; QAS 2021a; Ausmed 2019)

Assessing Pupillary Reaction

When we are assessing the patient’s pupils, we are gaining information regarding the brain and determining whether there has been an increase in intracranial pressure.

The pupils are assessed for their size and shape, as well as how they react to the presence of light. They should be round and equal in size.

The size of the pupils can vary, however, the normal range is 2 to 6 mm in diameter. Upon shining a bright light into each eye, the pupils should constrict briskly to a smaller size (QAS 2021a).

The reactions to light can be described as brisk, sluggish or non-reactive/fixed.

Both eyes should be checked and compared against each other. Generally, any change that occurs during an assessment of the pupils indicates a change in the individual’s intracranial pressure and may signify a neurological emergency.

Acute pupillary dilation in patients who have suffered a head injury is thought to be caused by compression of the third cranial nerve from brain oedema and herniation, or alternatively, from a decrease of blood flow to the brain stem, resulting in brain stem ischaemia (Koutoukidis et al. 2017; Majdan 2015).

Assessing Motor Function

Motor function assessment needs to be individualised, and the techniques used should be dependent on the patient’s condition.

For example, if the patient is conscious, the assessment may be made by observing their motor response to commands such as ‘squeeze my hands’. If they are unconscious or unable to provide accurate responses, you may only be able to assess motor function by observation.

You should also take note of the strength of their limbs, whether they are experiencing any weakness, and if these effects are bilateral or unilateral.

Limb strength can be described as either:

• Normal power
• Mild weakness
• Severe weakness
• Spastic flexion
• Extension
• No response.

Generally, this assessment focuses on the arms and legs and will look for any improvement or deterioration in function. However, it must be noted that lower limb function may impact spinal function in some patients and this can disrupt the assessment findings (Koutoukidis et al. 2017; Mooney & Comerford 2003).

Assessing Vital Signs

Vital signs are also assessed in conjunction with neurological observations in order to gain a full picture of the patient’s current health status.

Changes in vitals may indicate a deterioration of the patient’s neurological condition and can also provide clues to any other medical problems the individual may be experiencing. Depending on the findings of the assessment, further neurological examinations and diagnostic tests may be required.

Overcoming Challenges in Neurological Assessments

As mentioned above, there have been concerns raised about the consistency of neurological assessments, especially in regards to assessing pupil size and motor function.

This remains one of the major challenges in regards to neurological assessment. In order to ensure the reliability of neurological assessment and the GCS, it is important that all health professionals conducting these assessments are:

1. Fully educated and competent in the use of the GCS and the neurological observation tools being used within their health service, and
2. Generating discussion together regarding their patient’s neurological condition.

Additional Resources

• Causes of Acute Neurological Deterioration | Ausmed Article
• Vital Signs Basics | Ausmed Article

References

• Ausmed Editorial Team 2019, 'Vital Signs Basics', Ausmed, viewed 25 June 2021, https://www.ausmed.com.au/cpd/articles/vital-signs
• Jain, S & Iverson, L M 2020, 'Glasgow Coma Scale', StatPearls, viewed 25 June 2021, https://www.ncbi.nlm.nih.gov/books/NBK513298/
• Koutoukidis, G, Stainton, K & Hughson, J (eds) 2017, Tabbner’s Nursing Care: Theory and Practice, 7^th edn, Elsevier, Chatswood.
• Majdan, M, Steyerberg, E W, Nieboer, D, Mauritz, W, Rusnak, M & Lingsma, HR 2015, 'Glasgow Coma Scale Motor Score and Pupillary Reaction to Predict Six-month Mortality in Patients With Traumatic Brain Injury: Comparison of Field and Admission Assessment', Journal of Neurotrauma, vol. 32, no. 2, pp. 101-108, viewed 27 March 2018, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4291088/
• Mooney, G P & Comerford, D M 2003, 'Neurological Observations', Neurology, vol. 99, no. 17, pp. 24, viewed 27 March 2018,  https://www.nursingtimes.net/clinical-archive/neurology/neurological-observations/205473.article
• Queensland Ambulance Service 2021b, Clinical Practice Procedures: Assessment/Glasgow Coma Scale, State of Queensland, viewed 25 June 2021, https://www.ambulance.qld.gov.au/docs/clinical/cpp/CPP_Glasgow%20Coma%20Scale.pdf
• Queensland Ambulance Service 2021a, Clinical Practice Procedures: Assessment/Neurological Assessment, State of Queensland, viewed 25 June 2021, https://www.ambulance.qld.gov.au/docs/clinical/cpp/CPP_Neurological%20assessment.pdf
• Queensland Health 2013, Metro South Health | Clinical Form - Neurological Observation Sheet, Queensland Government, viewed 25 June 2021, https://csds.qld.edu.au/sdc/Provectus/ALS/Post-resuscitation%20care/files/neuro-observation-sheet.pdf
• Reith, F C M, Brennan, P M, Maas, A I R & Teasdale, G M 2015, 'Lack of Standardization in the Use of the Glasgow Coma Scale: Results of International Surveys', Journal of Neurotrauma, vol. 33, no. 1, pp. 89-94, viewed 27 March 2018, http://online.liebertpub.com/doi/abs/10.1089/neu.2014.3843
• Romanelli, D & Farrell, M W 2021, 'AVPU Score', StatPearls, viewed 12 September 2019, https://www.ncbi.nlm.nih.gov/books/NBK538431/
• Teasdale, G 2015, Glasgow Coma Scale: Do it This Way, GCS, viewed 27 March 2018, https://www.glasgowcomascale.org/downloads/GCS-Assessment-Aid-English.pdf?v=3