Cranial Nerve I—Olfactory Test

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What should be avoided when testing the sense of smell for cranial nerve I?

Familiar nonirritating odors like cloves, coffee, soap, or vanilla

Noxious odors like ammonia that might stimulate CN V (correct)

Substances that have a very strong and pleasant odor

Testing the sense of smell in a quiet environment

How is the sense of smell tested for cranial nerve I?

By asking the patient to keep both eyes open while identifying familiar odors

By occluding one nostril and testing smell in the other with familiar nonirritating odors (correct)

By presenting the patient with irritating odors

By testing the patient's sense of smell in a noisy environment

What is anisocoria?

A visual field defect

A difference of >0.4 mm in the diameter of one pupil compared to the other (correct)

An abnormality in peripheral vision

A complaint of partial loss of vision

Why should visual fields be tested by confrontation for cranial nerve II?

To reveal a visual field defect, an abnormality in peripheral vision such as homonymous hemianopsia Signup and view all the answers

What should be inspected with an ophthalmoscope to test cranial nerve II?

The optic fundi paying special attention to the optic discs Signup and view all the answers

What is missed when testing only one eye for visual fields for cranial nerve II?

"Homonymous hemianopsia" which describes a visual field defect Signup and view all the answers

Which of the following does the near response test assess?

Pupillary constriction, convergence, and lens accommodation Signup and view all the answers

What may be indicated by a large pupil reacting poorly to light and worsening anisocoria in light?

Normal pupillary constriction Signup and view all the answers

In which condition may both pupils react to light and anisocoria worsen in darkness?

Horner syndrome Signup and view all the answers

What is indicated by prechiasmal defects seen in glaucoma, retinal emboli, and optic neuritis?

Visual acuity poor Signup and view all the answers

What is an indication of postchiasmal lesions in the occipital or parietal lobe?

Homonymous hemianopsias or quadrantanopsias Signup and view all the answers

What may be suggested by a large pupil with abnormal pupillary constriction and the presence of ptosis and ophthalmoplegia?

Intracranial aneurysm Signup and view all the answers

What are the common causes of loss of smell as mentioned in the text?

Smoking and aging Signup and view all the answers

What does the examination of the optic fundi using an ophthalmoscope specifically look for?

Papilledema, optic atrophy, and cup enlargement Signup and view all the answers

What are the associated findings of stroke in relation to visual acuity?

Visual acuity poor Signup and view all the answers

What should be inspected carefully when examining each optic disc with an ophthalmoscope?

Bulging and blurred margins Signup and view all the answers

What involuntary jerking movement of the eyes should the examiner identify, noting the direction of gaze, the plane of the movement, and the direction of the quick and slow components?

Nystagmus Signup and view all the answers

What should be identified if diplopia is determined to be monocular or binocular by asking the patient to cover one eye, then the other?

The cause of diplopia Signup and view all the answers

In testing extraocular movements, what causes diplopia and loss of conjugate movements in any of the six directions?

Nystagmus Signup and view all the answers

When asking the patient to firmly clench the teeth, which cranial nerve and motor function is being assessed?

Cranial Nerve V - Trigeminal Motor Signup and view all the answers

What normal variant is observed in approximately one third of patients when examining for ptosis?

Slight difference in the width of the palpebral fissures Signup and view all the answers

During examination, what should be observed to determine if ptosis is present?

Slight difference in the width of the palpebral fissures Signup and view all the answers

What is the most likely cause of monocular diplopia?

Glasses or contact lenses Signup and view all the answers

What is a common cause of ptosis?

CN III palsy Signup and view all the answers

Which condition is associated with binocular diplopia?

Myasthenia gravis Signup and view all the answers

What might be indicated by difficulty clenching the jaw or moving it to the opposite side?

Massetter and lateral pterygoid weakness Signup and view all the answers

In brainstem lesions, what type of sensory loss is observed?

Contralateral facial and body sensory loss Signup and view all the answers

What motor function is being assessed when the patient is asked to firmly clench their teeth?

Facial muscle weakness Signup and view all the answers

What might be indicated by a large pupil reacting poorly to light and worsening anisocoria in light?