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Cranial Nerve Assessment Overview

Jun 9, 2025

Overview

This lecture covers the nursing assessment of cranial nerves I-XII, including key testing steps and normal findings for each nerve.

Preparation Steps

  • Provide privacy, perform hand hygiene, and explain procedures to the patient before beginning the assessment.

Cranial Nerve Assessment

Cranial Nerve I: Olfactory

  • Test smell by having the patient identify a pleasant scent with eyes closed.

Cranial Nerve II: Optic

  • Assess peripheral vision using the confrontation visual field test.
  • Evaluate visual acuity with a Snellen chart (record results as 20/20, 20/30, etc.).

Cranial Nerves III, IV, VI: Oculomotor, Trochlear, Abducens

  • Assess extraocular movements in six cardinal fields of gaze to check for nystagmus (involuntary eye movement).
  • Test pupillary response to light (pupils constrict when exposed to light).
  • Check for accommodation by moving an object toward the nose (pupils constrict, eyes cross).
  • Document as PERRLA: Pupils Equal, Round, Reactive to Light, and Accommodation.

Cranial Nerve V: Trigeminal

  • Palpate masseter and temporalis muscles as patient clenches teeth; check strength against resistance.

Cranial Nerve VII: Facial

  • Assess facial symmetry by asking the patient to close eyes tightly, smile, and puff cheeks.

Cranial Nerve VIII: Vestibulocochlear

  • Test hearing by occluding one ear and whispering words into the other; patient repeats the words.

Cranial Nerves IX & X: Glossopharyngeal & Vagus

  • Ask the patient to say "ah" and observe uvula movement.
  • Test gag reflex by gently touching the back of the throat.
  • Assess ability to speak and swallow.

Cranial Nerve XI: Accessory

  • Have the patient shrug shoulders and turn head against resistance to check muscle strength.

Cranial Nerve XII: Hypoglossal

  • Ask the patient to stick out tongue and move it side to side.

Key Terms & Definitions

  • PERRLA — Pupils Equal, Round, Reactive to Light, and Accommodation
  • Nystagmus — Involuntary, rapid movement of the eyes
  • Snellen chart — Tool to measure visual acuity
  • Accommodation — Pupillary constriction and eye crossing when focusing on a near object

Action Items / Next Steps

  • Watch the head-to-toe nursing assessment video for comprehensive skills review.
  • Practice documenting cranial nerve findings accurately after each assessment.