Lecture #26: DPR: Neurologic Exam Part 1: Mental Status, Cranial Nerves and the Eye Examination

Why is a screening neurological exam performed?

A screening neurological exam helps identify neurologic disease, localize lesions, assess symmetry of findings, and guide further diagnostic evaluation.

What are the main components of a screening neurological exam?

Mental status, cranial nerves, motor system, sensory system, reflexes, coordination, and gait.

What aspects are assessed in the mental status exam?

Level of alertness, orientation, speech, language, mood, thought content, and cognitive function.

What does orientation assess?

Orientation assesses awareness of person, place, time, and situation.

What does a Glasgow Coma Scale score of 3–8 indicate?

A score of 3–8 indicates coma and severe impairment of consciousness.

What is the function of cranial nerve I?

Cranial nerve I (olfactory) mediates the sense of smell.

How is cranial nerve I tested?

By having the patient identify non-irritating odors separately in each nostril with eyes closed.

What is the function of cranial nerve II?

Cranial nerve II (optic) mediates vision including visual acuity and visual fields.

How is visual acuity tested?

Using standardized eye charts such as Snellen, Tumbling E, or Rosenbaum charts.

What does 20/20 visual acuity mean?

The patient can read at 20 feet what a person with normal vision should read at 20 feet.

How are visual fields tested at the bedside?

By confrontation testing using finger movement in all four quadrants.

What cranial nerves control pupillary light reflexes?

CN II provides sensory input and CN III provides motor output.

What is the direct pupillary response?

Constriction of the pupil in the eye receiving light.

What is the consensual pupillary response?

Constriction of the opposite pupil when light is shined in one eye.

What does PERRLA stand for?

Pupils equal, round, reactive to light and accommodation.

What is accommodation?

Pupillary constriction and lens adjustment when focusing on a near object.

Which cranial nerves control extraocular movements?

CN III (oculomotor), CN IV (trochlear), and CN VI (abducens).

How are extraocular movements tested?

By having the patient follow the examiner’s finger through the six cardinal directions of gaze.

What does ptosis indicate?

Ptosis suggests oculomotor nerve dysfunction.

What is nystagmus?

Involuntary rhythmic oscillation of the eyes indicating vestibular or neurologic pathology.

What is assessed during funduscopic examination?

Optic disc clarity, color, cup-to-disc ratio, retinal vessels, and background retina.

What is the red reflex?

The normal orange-red glow of the retina seen through the pupil, indicating a clear visual axis.

What cranial nerve mediates facial sensation?

Cranial nerve V (trigeminal).

How is sensory function of CN V tested?

By testing light touch or pinprick in the ophthalmic, maxillary, and mandibular distributions.

What is the motor function of CN V?

Mastication using the masseter and temporalis muscles.

What is the corneal reflex?

Blinking in response to corneal stimulation mediated by CN V sensory input and CN VII motor output.

What cranial nerve controls facial expression?

Cranial nerve VII (facial).

How is CN VII motor function tested?

By asking the patient to raise eyebrows, close eyes tightly, smile, frown, puff cheeks, and show teeth.

What sensory function does CN VII provide?

Taste from the anterior two-thirds of the tongue.

How does peripheral facial nerve palsy differ from central palsy?

Peripheral palsy affects the entire face, while central palsy spares the forehead.

What cranial nerve mediates hearing and balance?

Cranial nerve VIII (vestibulocochlear).

How is gross hearing tested?

By whisper test or finger rub near each ear.

What is the Weber test used for?

To detect lateralization of sound and differentiate conductive from sensorineural hearing loss.

What does sound lateralizing to the affected ear indicate?

Conductive hearing loss.

What does sound lateralizing to the unaffected ear indicate?

Sensorineural hearing loss.

What is the Rinne test used for?

To compare air conduction and bone conduction of sound.

What is a normal Rinne test result?

Air conduction greater than bone conduction.

What cranial nerves are involved in swallowing and phonation?

Cranial nerves IX (glossopharyngeal) and X (vagus).

How are CN IX and X evaluated?

By assessing voice quality, swallowing, palate elevation, uvula position, and gag reflex.

What does asymmetrical palate elevation indicate?

Vagus nerve dysfunction.

What cranial nerve controls shoulder elevation and head rotation?

Cranial nerve XI (spinal accessory).

How is CN XI tested?

By asking the patient to shrug shoulders and turn head against resistance.

What cranial nerve controls tongue movement?

Cranial nerve XII (hypoglossal).

How is CN XII tested?

By observing tongue at rest and with protrusion for deviation, atrophy, or fasciculations.

What does tongue deviation toward one side indicate?

Weakness on the side of deviation due to hypoglossal nerve injury.

What should a normal cranial nerve exam demonstrate?

Symmetric function, intact sensation, normal strength, and coordinated movement.

Why is proper documentation of the neurological exam important?

It communicates findings clearly, supports diagnosis, and allows comparison over time.

What does a normal neurological exam note typically include?

Mental status, cranial nerve findings, motor strength, sensation, reflexes, coordination, and gait.

Why must exam findings be described objectively?

Objective documentation ensures accuracy, reproducibility, and clinical clarity.