Cranial Nerves Assessment Quiz

Cranial Nerves Assessment

• Cranial Nerve I (Olfactory): Tested by asking the patient to smell different scents (coffee, peppermint, cinnamon) while occluding the opposite nostril.

• Cranial Nerve II (Optic): Assessed by testing visual acuity (Snellen chart) and confrontation visual fields. For confrontation visual fields, the patient closes one eye and indicates the number of fingers the examiner is holding in the upper, lower, and middle visual fields while the patient stares straight ahead. Repeat with the opposite eye.

• Cranial Nerves III, IV, and VI (Oculomotor, Trochlear, and Abducens): Assessed by having the patient follow a penlight or object with their eyes in six cardinal fields of gaze (think "cat whiskers"). Also, assess pupillary responses to light and accommodation (constriction when a near object is moved closer to the nose). Normal findings include pupils being equal, round, reactive to light and accommodating (PERRLA).

• Cranial Nerve V (Trigeminal): Tested by having the patient clench their teeth (feel masseter and temporal muscles), and try to open their mouth against resistance. Important to examine the ophthalmic, maxillary, and mandibular branches.

• Cranial Nerve VII (Facial): Tested by observing facial expressions (closing eyes tightly, smiling, frowning, puffing out cheeks).

• Cranial Nerve VIII (Vestibulocochlear): Assess by having the patient repeat a whispered word or sound with one ear occluded at a time. The Rinne and Weber tests are used to distinguish between possible conduction and sensorineural hearing loss.

• Cranial Nerve IX (Glossopharyngeal): Tested by having the patient say "ahh" (observe uvula position) and test the gag reflex using a tongue depressor.

• Cranial Nerve X (Vagus): Assess for hoarseness and swallowing ability.

• Cranial Nerve XI (Accessory): Test shoulder shrug and head turning against resistance.

• Cranial Nerve XII (Hypoglossal): Instruct the patient to stick out their tongue and move it from side to side. Ensure the tongue is positioned centrally.

Coma Assessment

• Coma: Impaired arousal and awareness, often a serious, potentially life-threatening condition.

• Arousal: Wakefulness, determined by the brain stem's ascending reticular activating system.

• Coma Assessment: First, stabilize ABCs (airway, breathing, circulation). Next, assess level of consciousness using something like the Glasgow Coma Scale (GCS). Assess neurological function for focal or asymmetric findings. Obtain background info from relatives, noting history and pre-morbid behavior.

• Metabolic Coma: Pathophysiology involves toxic effects or depleted substrates in arousal centers. Respiratory patterns may be normal/hyperventilating or irregular (Cheyne-Stokes). Pupillary size may vary depending on the cause, but level of consciousness changes after pupil changes. Possible causes include uremia, liver failure, hyperglycemia, hypoglycemia, alcohol, drugs, hypothyroidism, or infections (meningitis, encephalitis).

• Structural Coma: The damage directly or indirectly compromises brain stem arousal areas. Respiratory patterns are often irregular (Cheyne-Stokes, ataxic, apneustic, central hyperventilation). Pupillary changes are generally unequal or unreactive to light (fixed) and level of consciousness changes before pupil changes. Possible causes include hemorrhage, infarction, tumors, or abscesses.

• Pupils in Coma: Pupil size, equality, and light reactions are important indicators regarding the cause and location of brain damage. Unilateral or bilateral unequal pupils (or fixed and dilated pupils) suggest structural lesions in the brain stem but remember that these symptoms can be associated with other conditions.

Syncope and Other Disorders

• Vasovagal Syncope: Caused by neurologically-mediated vasodepressor/bradycardia. Often occurs after prolonged standing, supine hypertension is common.

• Orthostatic Hypotension Syncope: Gravitational redistribution of blood, leading to decreased blood pressure after standing. Hypovolemia is also involved which is a decreased blood volume

• Cough Syncope: Neuromuscular response to severe coughing episodes leading to hypotension.

• Micturition Syncope: Sudden hypotension due to vasovagal reflex during urination after standing up.

• Cardiovascular Syncope: Arrhythmias (bradycardia, tachycardia), aortic stenosis, or myocardial infarction; can trigger decreased cardiac output or cerebral hypoperfusion.

• Massive Pulmonary Embolism Syncope: Sudden hypoxia or decreased cardiac output as a result of blood clots in lung arteries; usually occurs after periods on bed rest

• Disorders Resembling Syncope: Hypocapnia from hyperventilation, hypoglycemia, and functional neurological symptoms disorder (conversion disorder)

Apgar Score

• Apgar Score: Assessment of a newborn's status immediately after birth. Evaluates five components: heart rate, respiratory effort, muscle tone, reflex irritability, and skin color. Scores for each component (0–2) are summed to quantify the newborn's condition, immediately after childbirth