Cranial Nerve Lesions Flashcards
Pathology of CN XII
Deviation of tongue to damaged side on protrusion, possible muscle wasting and fasciculations
Cause of CNXII palsy
Possibly from head and neck malignancy and penetrating trauma
Recurrent layngeal nerve pathology
Dysphonia, aphonia, stridor
Causes of recurrent layngeal nerve pathology
Heart defects can irritate nerve, cancer of larnyx, thyroid gland, surgical complications
Pharyngeal and other vagus nerve pathology
Dysphagia, uvula deviation, loss of gag reflex, vasovagal syncope
Pathology of CNXI symptoms
Ipsilateral muscle wasting and paralysis of SCM and trapezius. Unable to move neck, shrug shoulders or rotate head
Causes of CNXI pathology
Mostly iatrogenic from procedures to cervical lymph nodes (biopsy/excision) and central line insertion
Symptoms of vestibular nerve damage
Vertigo, nystagmus, loss of equilibrium, nausea, vomiting
Causes of vestibular nerve damage
Vestibular neuritis, labyrinthitis, basillar skull fracture can damage nerve within acoustic meatus
Symptoms of cochlear nerve damage
Sensorineural hearing loss, tinnitus
Causes of cochlear nerve damage
Labyrinthitis, basillar skull fracture
Symptoms of glossopharyngeal neuralgia
Paroxysmal attacks of unilateral brief brain
Causes of glossopharyngeal neuralgia
Compression, less commonly from tumour, aneurysm or demyelination
Causes of abducent nerve pathology
SOL, diabetic neuropathy, thromboplebitis of cavernous sinus, small vessel disease, any pressure on brainstem
Intracranial features of CN VII palsy
Muscles of facial expression paralysed or weakened, reduced salivation, loss of taste on ipsilateral 2/3 tongue, ipsilateral hyperacusis (stapedus nerve), ipsilateral reduced lacrimal fluid (greater petrous nerve)
Causes of intracranial CN VII palsy
Infection related to external or middle ear
Extracranial features of CN VII palsy
Only muscle function is affected
Extracranial causes of CN VII palsy
NErve infection or parotid gland pathology
Causes of trochlear nerve palsy
Microvascular damage from diabetes or hypertension, congenital malformation, raised ICP, thrombophlebitis of cavernous sinus
Causes of trigeminal nerve palsy
Compression at root of nerve by intracranial artery, compression of venous loop as it enters brainstem, tumour, aneurysm or plaque
Features of CNV palsy
Severe paroxysmal facial pain
Features of CN VI palsy
Horizontal diplopia, resting adduction, inability to adduct eye
Features if Meyer’s loop is affected
Left superior quadrantanopsia
Causes of meyers loop pathology
Temporal lobe tumour
If there was a thrombosis of PCA what effects would if have on the optic nerve
Left homonymous hemianopsia with macular sparing
Features of Oculomotor palsy
Ptosis, down and out position, dilated pupil
Causes of oculomotor palsy
Raised ICP, PCA aneurysm, cavernous sinus infection, trauma, diabetes, MS, myasthenia gravis, giant cell arteritis
Olfactory nerve pathology symptoms
Anosmia
Causes of olfactory pathology
Infection, head injury, trauma, tumour in olfactory groove, parkinsons, AD, Kallman syndrome
Pathology of direct CN II lesion
Complete loss of vision in nerve supplying eye
Causes of CN II lesion
MS, trauma, glaucoma
Features of optic chaism pathology
Bitemporal hemianopsia
Features of right optic tract pathology
Left homonymous hemianopsia
Causes of bitemporal hemianopsia
Pituitary tumour
