Cranial Nerve Examinations Flashcards
Test for cranial nerve 1
- Ask if the patient has noticed a problem with their sense of smell.
- Ask the patient if their nostrils feel blocked on either side.
- Test each nostril in turn by occluding the other & ask if patient can identify the smell. Smells such as coffee often used. Ask the patient to close their eyes and waft the smell towards the patient. Ensure you know the smell you are testing! Use a different smell for each nostril. N.B. No vials available in the CSLC.
A patient complains of anosmia after a head injury. In which anatomical location is the lesion likely to be located?
Cribriform plate or olfactory bulb / tract
Tests for CN 2
Light reflex
Accommodation reflex
Visual fields
Visual acquity + Colour blindness
How to test light reflex
Check that the patient isn’t sensitive to bright light. Ask patient to fix on a distant object & then shine the light into one eye and watch the response in that eye - this is called the direct reflex. Do it again but watch the response in the other eye (again this should constrict) - this is called the consensual reflex. Repeat by shining the light into the other eye and check both the direct and consensual response. Shine torch in from the side rather than directly into the eye.
How to test accommodation reflex and what are you looking for
Ask patient to focus on something far in the background then focus on your finger which is approximately 6 inches from their face
Looking for convergence, pupil constriction and for the lens to change shape
What is the initial position of the examiner during a visual field test?
Opposite the patient at the same eye level and approximately 1m apart
What should the patient do with their glasses during the visual field test?
Remove their glasses unless visual acuity is very poor
Where should the patient focus their gaze during the visual field test?
On the examiner’s eyes, not their hands
What should be done if the patient cannot close one eye?
Cover the eye with a hand or disposable patch
Why is hand hygiene important during the visual field test?
To prevent infection transfer between the hand and the eye
How should the examiner bring their finger or pin into the patient’s visual field?
From the periphery of each quadrant to the center
What is important about the positioning of the examiner’s finger or pin during the test?
It should be equidistant between the examiner and the patient
What is the recommended technique for using hands during the visual field test?
Best to use both hands in turn for each eye
What should be compared at the end of the visual field test?
The examiner’s visual fields with the patient’s
