Cranial Nerves
What is the name of CN VIII?
Vestibulocochlear Nerve
What cranial nerves are involved in the pupillary light reflex?
CN II (optic)
CN III (oculomotor)
A patient presents with anosmia and altered perception of taste. What cranial nerve is involved?
CN I (olfactory)
Describe the findings of a central CN VII (facial) palsy due to a cortical stroke.
Contralateral lower facial weakness; may have associated hemiparesis.
What is Horner's syndrome?
Horner's syndrome is the unilateral loss of sympathetic efferent fibers.
What cranial nerves do not arise from the brainstem?
CN I (olfactory)
CN II (optic)
When examining the pupils, what are the two key findings?
(1) Whether or not the pupils react to light
(2) Whether the pupils are symmetric or asymmetric
CN IX (glossopharyngeal)
How does a patient compensate for a CN IV (trochlear) lesion?
Patients may compensate with a head tilt.
True or False: Weber's Syndrome is a ventral midbrain lesion.
True
What are the devisions of the trigeminal nerve (CN V)?
V1 - ophthalmic
V2 - maxillary
V3 - mandibular
Cold water calorics are performed in a patient's left ear. Describe what happens.
The patient's eyes will move towards the left. If the patient has an intact cortex, the patient will have nystagmus in the opposite direction.
Hearing loss
Vertigo
Motion sickness
Tinnitus
A deficit of the abducens nerve (CN VI) leads to the inability to abduct the eye. What is the most typical cause of this deficit?
CN VI deficits are typically due to increased intracranial pressure.
In this syndrome, all afferent and efferent tracts are destroyed. Sometimes the only cranial nerve III (oculomotor) is left intact. What is the name of this syndrome?
Locked In Syndrome
Are the following cranial nerves sensory, motor, or both: CN I, CN IV, and CN VII?
CN I = sensory
CN IV = motor
CN VII = both
A reflex is performed on an unconscious patient without a brainstem lesion. During this reflex, the patient's head is turned which causes the eyes to move conjugately in the opposite direction. What is the name of this reflex?
Occulocephalic Reflex or Doll's Eyes or Cervico-ocular Reflex
A patient presents with shoulder pain and heaviness, difficulty to raise hand overhead, and neckline asymmetry. It is determined that they are suffering from a cranial nerve palsy. What are three possible causes of this cranial nerve palsy?
CN XI (accessory nerve)
May be iatrogenic (most commonly from surgery of lateral cervical region), trauma, or tumor
If a patient presents to the office with complete ptosis, what cranial nerve is involved and why?
CN III; it innervates the levator palpebrae superioris muscle
What syndrome can be described as severe unilateral facial pain? What cranial nerve is involved with this syndrome?
Trigeminal Neuralgia; CN V (trigeminal)
What cranial nerves are involved in the optic system?
CN II (optic)
CN III (oculomotor)
CN IV (trochlear)
CN VI (abducens)
If there is a lesion in the right optic nerve (CN II), what findings are expected when the pupillary light reflex is performed?
When the light is placed on the right eye, both pupils will remain dilated.
When the light is placed on the left eye, both pupils will constrict.
You suspect a patient is suffering from a hypoglossal nerve (CN XII) palsy. What is one diagnostic exam that you may perform to confirm your thoughts?
Press tongue against cheek -- pressure to the cheek of the affected side might be increased
Stick out their tongue -- deviation of tongue to ipsilateral side when protruded (due to weakness of the ipsilateral muscles)
If a patient has an MLF (medial longitudinal fasciculus) lesion, what cranial nerves would be involved?
CN III (oculomotor)
CN VI (abducens)
Foville's Syndrome includes all the features of Millard-Gubler Syndrome as well as what other symptoms?
Contralateral loss of proprioception and vibration