Injuries to Cranial Nerves Flashcards
An injury to CN XII would cause what?
Periphal lesion –> protruded tongue deviates toward side of injury due to paralyis of tongue muscles
What are symptoms of Bell’s palsy?
- Facial muscle paralysis
- Cannot close eyelids (orbicularis oculi)
- Angle of mouth droops (paralysis of m.’s around mouth)
- Forehead does not wrinkle (frontalis)
An injury to CN IX would result in what?
- Dysphagia
- Dysarthria
- Changes in blood pressure (chemoreceptors in carotid body, barorecptors in carotid sinus)
- Loss of taste sensation from posterior 1/3 of tongue
An injury to CN VI would cause what?
Abducent nerve pasly characterized by:
- Horizontal diplopia (double vision)
- Impaired eye abduction
- A tendency for the eye to turn medially (due to unopposed action of medial rectus m.)
An injury to CN V2 would cause what?
Anesthesia of maxillary region
Trigeminal neuralgia / Tic douloureux (intermittent excruciating pain)
Injury to CN VII distal to the geniculate ganglion results in what?
- Facial muscle paralysis
- Loss of taste (anterior 2/3rds of tongue)
- Loss of salivation from sublingual and submandibular glands
- Hyperacusis (due to paralysis of stapedius m.)
An injury to CN VIII would cause what?
Hearing impairment or loss
Vertigo (dizziness)
What would cause an injury to CN II?
Eyeball trauma
Bell’s palsy is caused by damage to what area?
Injury in region of parotid gland (i.e. distal to stylomastoid foramen)
Injury to CN VII - Facial
What is hyperacusis?
Condition characterized by an over-sensitivity to certain frequency and volume ranges of sound caused by damage to CN VII distal to the geniculalte ganglion.
Injury to CN VII distal to the stylomastoid foramen results in what?
Facial muscle paralysis
What would cause an injury to CN I?
Fracture of the cribiform plate
An injury to CN V3 would cause what?
Sensory: Anesthesia to mandibular region
Motor: difficulty chewing
What would cause an injury to CN V2?
Inflammation
What would cause an injury to CN III?
Cavernous sinus injury
Aneurysm of posterior cerebral or superior cerebellar arteries
A drooping eyelid (ptosis) would indicate an injury to which muscle and nerve?
Levator palpebrae muscle
CN III
An injury to CN I would result in what?
Anosmia (loss of sense of smell)
An injury to CN IV would result in what?
An inability to look down when eye is adducted (diplopia)
An injury to the chorda tympani nerve would cause what?
Loss of taste sensation from anterior 2/3rds of tongue
An injury to CN III would cause what?
Complete oculomotor nerve palsy characterized by:
- Ptosis (eyelid droops due to paralyis of levator palpebrae m.)
- A resting eye position that is down and out
- A pupil that is fixed and dilated (mydriasis)
Injury to CN X would result in what?
- Sagging soft palate
- Difficulty coughing, clearing throat, swallowing (reccurrent laryngeal n. injury)
- Dysphagia (due to paralysis of muscles in soft palate)
What is dysphagia?
Difficulty swallowing
Injury to CN VII proximal to branching off of chorda tympani results in what?
- Facial muscle paralysis
- Loss of taste (anterior 2/3rds of tongue)
- Loss of salivation from sublingual and submandibular glands
What would cause an injury to CN IX?
Neck laceration
What is dysarthria?
Speech difficulty
What would cause an injury to CN IV?
Cavernous sinus injury
An injury to CN II would cause what?
Anopsias (visual field defects)
An injury to CN V1 would result in what?
Anesthesia in ophthalmic region (loss of pain and touch sensation)
What is mydriasis?
Pupil dilation due to paralysis of sphincter pupillae muscle and unopposed action of dilaor pupillae muscle.
The stapedius muscle is innervated by what nerve?
CN VII - Facial
What would cause an injury to CN XI?
Neck laceration
What would cause an injury to CN V1?
Inflammation
Injury to CN VII with involvement of the greater petrosal nerve results in what?
- Facial muscle paralysis
- Loss of taste (anterior 2/3rds of tongue)
- Loss of salivation from sublingual and submandibular glands
- Hyperacusis (due to paralysis of stapedius m.)
- Loss of taste (palate)
- Loss of lacrimation
What would cause an injury to CN VIII?
A tumor
What would cause an injury to CN V3?
Inflammation
An injury to CN XI would result in what?
- Weakness in turning head to opposite side (sternocleidomastoid)
- Weakness in shrugging shoulders (trapezius)
What would cause an injury to CN XII?
Neck laceration
What would cause an injury to CN VI?
Cavernous sinus injury
Fracture of base of skull
