Neuro Flashcards
Neurological assessment - LOC
Level of consciousness (LOC)
> Using the AVPU acronym is useful as part of the primary survey.
> Using the Glasgow Coma Scale to ascertain a patient’s Glasgow Coma Score (GCS) should be performed as soon as possible, and repeated throughout patient management to detect any trends. Refer to the Glasgow Coma Scale skill sheet for more information
Neurology assessment - Taking a history
> Ask questions that systematically explore each symptom. Examples of symptoms may include:
– Headache.
– Dizziness/vertigo.
– Light-headedness/faint.
– Visual disturbances e.g. blurred vision, double vision, wavy appearance of visual images, rainbows or halos.
– Motor/sensory/speech losses.
– Nausea.
– Altered sensations e.g. numbness, tingling, pins and needles.
Ensure you ascertain what the patient’s previous medical history is. View hospital discharge summaries if they are available.
Document all the important aspects of the history, including pertinent negatives.
SAMPLE and OPQRST
Neurology assessment - Pupils
Determine pupil size:
> The size of a person’s pupils are determined by the brightness of ambient light and the balance of sympathetic nervous system stimulation (causing dilation) and parasympathetic nervous system stimulation (causing constriction). As a rule:
– <2 mm is considered pinpoint
– 2–6 mm is considered normal
– >6 mm is considered dilated.
> Up to 20% of normal people have asymmetrical pupils and the medical term for this is anisocoria. Most have less than 1 mm difference in size but it is possible to have a difference of up to 2–4 mm in the absence of pathology.
Assess pupil reactivity:
> Use a small bright light, such as that on a pupil torch.
> Cover one eye, and shine the light directly into the open eye – this should result in rapid constriction.
> Repeat the assessment on the other eye. Both reactions should be equal.
> Importantly, if you shine light in one eye, both pupils should constrict:
– If you shine a light in one eye and nothing happens in either eye, there is a problem with that eye, the signal out of that eye or there is a problem with the signal in both eyes.
– If you shine a light in one eye and that eye constricts, but the other doesn’t, there is a problem with the signal into the other eye.
– If you shine a light in one eye and the eye does not constrict but the other one does, there is probably a problem with the signal into the eye the light was shone into, but not out of it.
Note any abnormal findings, for example:
> Pupil deviation from midline
> Dilated/ constricted and reactive/non-reactive
pupils:
– If both pupils are dilated and unreactive,
it usually reflects bilateral pressure on the oculomotor nerves, for example from severe bleeding or swelling following traumatic brain injury.
– If one pupil is dilated and unreactive it usually reflects unilateral pressure on one oculomotor nerve, for example from severe bleeding on one side from an extra-dural haemorrhage or an intra-cerebral haemorrhage. In this setting the dilated pupil is on the same side as the raised pressure.
– Bilateral constricted (or pinpoint) pupils that appear to be unreactive may be seen if the patient has opiate poisoning or a brain stem stroke. In this setting the pupils are often reactive, but the pupils are so small it is hard to see.
– Bilateral dilated pupils may be seen if the patient has poisoning with medicines that have significant anti-cholinergic side effects (for example tricyclics or tramadol) or there is very high bilateral pressure within the brain.
> Nystagmus
> Vastly differing pupil sizes.
Assessing the pupils for size and reactivity is usually distracting and unhelpful unless the patient has a possible direct eye injury or a significantly altered level of consciousness. If the patient has a normal or near normal GCS, even in the setting of traumatic brain injury, any difference is likely to be non-pathological.
If the patient is unable to obey commands, assessing the pupils for size and reactivity to light is useful because it may reveal a sign of raised intra-cranial pressure. In particular, changes over time are more useful than a single assessment, noting that pupil dilatation as a result of pressure on the oculomotor nerve is a very late sign of raised intracranial pressure.
Neurology assessment- motor skills
Assess the patient’s coordination. This can be done using the finger nose test.
> Listen for any slurring of speech.
> Assess muscular strength and tone:
– Look for facial weakness by asking the patient to raise their eyebrows, smile, and frown.
– Observe the patient’s tongue for asymmetry. You may choose to ask them to poke their tongue out for a short period. Note any tremors or deviation from midline.
– Assess the patient’s grip strength.
– Assess the patient’s ability to push and pull, with both their hands and feet.
> Look for any abnormal movements such as seizures, tremors or flexion/extension.
> Perform the Romberg’s test if possible to assess the patient’s balance:
– Stand beside the patient and be prepared to assist if they stumble.
– Ask the patient to stand with their feet together, place their arms by their side, get their balance and then close their eyes.
– Observe how long the patient can maintain the stance. A patient with normal balance should be able to maintain the stance without stumbling for more than 15 seconds.
> Observe whether the patient has an abnormal gait (manner of walking).
Neurology assessment - sensory
Assess the patient’s hearing and ability to understand verbal communication.
> Assess superficial sensation (i.e. light touch or pain).
Describe the indications for a comprehensive neurological assessment.
> Patients with an impaired level of consciousness
> Patients with suspected neurological dysfunction
Describe the contraindications and cautions of performing a neurological assessment
Contraindications:
> None.
Cautions:
> A time-critical condition. If a patient has a time-critical condition, patient management and expedient transport take precedence over performing a comprehensive neurological assessment
Demonstrate a comprehensive neurological assessment
A competent demonstration includes:
Assess level of consciousness: using AVPU initially, then GCS.
Obtain a focused history:
> Questions are systematic and appropriate for patient condition.
> Questioning on previous medical history.
Assess for pupil size, reactivity, and movement.
Assess motor function:
> Assess the patient’s coordination (including gait)
> Listen for any slurring of speech.
> Assess muscular strength and tone:
– Look for facial weakness
– Observe the patient’s tongue for asymmetry
– Assess the patient’s grip strength
– Assess the patient’s ability to push and pull, with both their hands and feet
