Disorders of Cranial Nerves Flashcards
Which cranial nerves carry special sensory information?
I - olfaction
II - vision
VII, IX, X - taste
VIII - hearing (and balance)
What nerve carries the majority of the general sensory information form the face?
V
What nerves control the muscles of the eye?
III
IV
VI
What nerve controls the muscles of mastication?
V
What nerve controls the muscles of facial expression?
VII
What nerve controls the muscles of the pharynx and larynx?
X
What nerve controls the sternocleidomastoid and trapezius muscles?
XI
What nerve controls pupillary constriction?
III
What nerve controls lacrimation?
VII
What nerve controls salivation from the submandibular and sublingual glands?
VII
What nerve controls salivation from the parotid gland?
IX
How can the optic nerve be tested?
Visual acuity
Visual fields
Pupillary reactions
Fundoscopy
How can nerves III, IV and VI be tested?
Ptosis?
Pupils of equal size?
Pupillary reactions
Eye movements - vertical and horizontal
How can the trigeminal nerve be tested?
Sensation in V1, V2 and V3
Powers in the muscles of mastication
Corneal reflex
Jaw jerk
How can the facial nerve be tested?
Muscles of facial expression
Corneal reflex
(Taste)
How can the vestibulocochlear nerve be tested?
Hearing using Rinne’s and Weber’s test
Vestibular function using Hallpike-Dix manoeuvre and Untenberger’s test
How can the glossopharyngeal and Vagus nerves be tested?
Movement of the palate
Gag reflex
(Quality of speech and cough)
How can the spinal acc4essory nerve be tested?
Head turning and shoulder shrugging
How can the hypoglossal nerve be tested?
Appearance and movement of the tongue
What are the four cranial nerve reflexes?
Pupillary light reflex
Corneal reflex
Jaw jerk
Gag reflex
What does the combination of III, IV and VI signs suggest in terms of damage to the head?
SOF disruption
What is optic neuritis?
Demyelination within the optic nerve
Causes monocular visual loss and eye is painful on movement
Reduced visual acuity and colour vision
What degenerative disease is optic neuritis often associated with?
MS
What is the result of loss of parasympathetic innervation to the eye?
Fixed, dilated pupil e.g. III nerve palsy
What are some nerve disorders that cause eye movement disorders?
Isolated third nerve palsy
Isolated fourth nerve palsy
Isolated sixth nerve palsy
Nystatgmus
What are the two forms of third nerve palsy?
Microvascular - diabetes, hypertension - painless, pupil spared
Compressive - posterior communicating artery aneurysm, raised ICP - painful, pupil affected
Give some causes for isolated sixth nerve palsy
Idiopathic
Diabetes
Meningitis
Raised ICP
What are some causes of nystagmus?
Congenital
Secondary to serous visual impairment
Secondary to peripheral vascular problem
What is trigeminal neuralgia?
Paroxysmal attacks of lancinating pain
Trigger is usually a vascular loop compressing the fifth nerve in the posterior fossa
How is trigeminal neuralgia treated?
With carbamazepine or surgery if severe
What is Bell’s palsy?
A unilateral facial weakness of LMN type
Often preceded by pain behind the ear
Eye closure is affected = risk of corneal damage
Treated with steroids
What is vestibular neuronitis?
Sudden onset disabling vertigo
Vomiting
Gradual recovery
Cause uncertain
What is dysarthria?
Disordered articulation, slurring of speech
What is dysphagia?
Difficulty swallowing
Is bulbar palsy LMN or UMN?
LMN
Is pseudobulbar palsy LMN or UMN?
UMN
What is pseudobulbar palsy?
Bilateral UMN lesions e.g. in vascular lesions of both internal capsules, MND
Results in - dysarthria, dysphonia, dysphagia, spastic, immobile tongue, brisk jaw jerk, brisk gag reflex
What is bulbar palsy?
Bilateral LMN lesions affecting IX-XII
Causes include MND, polio, tumours
Results in - wasted, fasciculating tongue, dysarthria, dysphonia, dysphagia
