The advanced practice registered nurse (APRN) is assessing an 86 year-old patient. The APRN notes a blowing diastolic murmur (grade Ill out of VI), heard best at the left 2nd through 4th intercostal spaces. What is the most likely cause of the diastolic murmur in this patient?

A. Cardinal reflex; CN IV & V is incorrect because there is no reflex termed “cardinal reflex” in clinical neuroassessment. CN IV (trochlear) controls superior oblique eye movement and is not involved in blinking. CN V (trigeminal) is partially involved in corneal sensation, but the reflex is paired with CN VII.

B. Corneal reflex; CN V & VII is correct. The corneal reflex is elicited by gently touching the cornea with a cotton wisp, which should trigger bilateral blinking. This reflex assesses CN V (trigeminal nerve, ophthalmic branch) for sensory input from the cornea and CN VII (facial nerve) for motor output causing the orbicularis oculi muscle to blink. Testing the corneal reflex is particularly important in facial trauma, altered consciousness, or neurological deficits.

C. Oculocephalic reflex; CN III, VI, & VIII is incorrect because this is the “doll’s eyes” reflex, used to assess brainstem function in unconscious patients by turning the head and observing eye movement. It does not involve corneal stimulation.

D. Oculovestibular reflex; CN III, VII, & VIII is incorrect because this refers to the caloric test (cold water in the ear canal to observe eye movements) to evaluate brainstem integrity. It is unrelated to corneal stimulation.

A. Direct reaction is incorrect because the direct pupillary light reflex refers specifically to the constriction of the pupil that is directly exposed to light. It does not describe the behavior of the opposite pupil, which is responding indirectly. Assessing the direct reaction helps evaluate the function of the afferent pathway (optic nerve, CN II) and the efferent pathway (oculomotor nerve, CN III) of the illuminated eye.

B. Consensual reaction is correct because the consensual pupillary light reflex describes the simultaneous constriction of the pupil opposite to the one being directly stimulated by light. When light enters one eye, afferent signals travel via the optic nerve (CN II) to the pretectal nuclei in the midbrain, which then communicate bilaterally with the Edinger-Westphal nuclei. Efferent signals are sent via the oculomotor nerves (CN III) to both pupils, resulting in constriction of both the directly exposed pupil and the contralateral pupil. The consensual reflex demonstrates bilateral integrity of the optic and oculomotor pathways, even when only one eye is exposed to light.

C. Near reaction is incorrect because it refers to pupillary constriction that occurs when the eyes focus on a near object, as part of the accommodation reflex, and is not triggered by light. It is primarily a test of focusing ability rather than pupillary light response.

D. Accommodation is incorrect because it involves a triad of responses—pupillary constriction, lens thickening, and convergence of the eyes—when shifting focus from a distant to a near object. While pupillary constriction occurs, it is not in response to light and therefore is distinct from the consensual light reflex.