Physical assessment - Cranial nerves: Nursing

Assessment of the cranial nerves should be completed as part of a comprehensive assessment, like during a routine physical exam, or as part of a focused exam if a client is experiencing neurological issues like a drooping eyelid or trouble swallowing. Examination of the 12 pairs of cranial nerves provides information about the client’s sensory and motor function of the head, neck, and torso. Let’s review the process of completing a cranial nerve assessment.

Okay, the supplies you’ll need for your assessment include a penlight; a sample of an odor that is easily identified like an alcohol pad, peppermint, or coffee; a cotton ball; a cotton swab; sweet, sour, salty, and bitter taste solutions, a Snellen eye chart, a tongue blade, and gloves. Then, prepare for the exam by ensuring your client is in a comfortable position, that your hands are warm, and that the temperature in the room is comfortable. Provide privacy by closing the door and curtains.

Before getting started, explain the procedure to your client and be sure to answer any questions they might have before obtaining verbal consent. Then, perform hand hygiene and collect your supplies.

Methods of assessment for cranial nerve evaluation include inspection, mainly watching to see if the client is able to perform the requested tasks, and palpation.

Okay, let’s start with cranial nerve I, the olfactory nerve. You can test the function of this nerve by asking your client to close their eyes, occluding one of the nares, and holding the sample about 6 inches from the open nare, and asking them to identify the odor. Repeat with the opposite nare. They should be able to correctly identify the odor. Clients who cannot identify the odor might have a partial or complete loss of smell, known as anosmia.

Next is cranial nerve II, also known as the optic nerve, which is responsible for visual acuity, or how your client can see. If you are using a wall-mounted Snellen chart, position your client 20 feet or 6 meters from the chart. Then, ask your client to cover one eye, and read the letters on the lines until the letters become too small for them to read. Repeat with the other eye. You’ll record their visual acuity as a fraction, where the numerator indicates the distance your client is from the chart, and the denominator indicates the distance at which a normal eye can read the line on the chart. For example, 20/40 vision means that the client can read at 20 feet what the average client can read at 40 feet. In other words, the larger the denominator, the worse the vision. Vision that’s not able to be corrected to better than 20/200 means the client is legally blind.