Cranial Nerve Lesions Flashcards
Presentation of Oculomotor nerve palsy
-Ptosis, down and out eye (paralysis of adduction, elevation, and depression= intorsion)
-Dilated and fixed pupil
-Diplopia (worsens when head is turned away from side of lesion).
OCULOMOTOR PALSY LEAVES YOU DOWN AND OUT
Diagnosis of oculomotor nerve palsy
-MRI brain/ angiography (compressive lesion: posterior communicating artery aneurysm)
-Blood pressure
-Blood glucose (poorly controlled DM)
-Risk factors for atherosclerosis or arteritis
Presentation of Trochlear nerve palsy
-Vertical diplopia, exacerbated on downgaze away from side of affected muscle- worsens when patient turns head towards paralysed muscle (compensatory head tilt to opposite side of lesion).
-Extorsion of the eye, inability to depress and abduct the eyeball simultaneously (defective downward gaze), tilt head to opposite side.
WITH DAMAGE TO THE CN 4, YOU CANNOT LOOK AT THE FLOOR
Diagnosis of trochlear nerve palsy
MRI brain (trauma, cancer, persistent after 3 months, progression of symptoms)
Presentation of abducens nerve palsy
-Defective abduction (inability to look laterally in affected eye)
-Horizontal diplopia (worsens when looking at distant objects/ towards affected side)
-Medial deviation of affected eye at primary gaze/ convergent squint.
MOST COMMON- ABDUCENS CANNOT ABDUCT
Diagnosis of abducens nerve palsy
MRI head, ischaemic risk factors, autoimmune, thyroid and myasthenia gravis
Presentation of optic nerve lesions
-Impaired vision, blindness, Uhthoff phenomenon (MS), jaw claudication and headache (GCA)
-Complete transection: ipsilateral blindness + loss of pupillary reflex
-Pituitary adenoma: bitemporal hemianopia
-Unilateral optic nerve dysfunction: relative afferent pupillary defect
Diagnosis of optic nerve lesion
-Fundoscopy
-MRI (optic neuritis, tumour, degenerative diseases)
-CT head (trauma)
-ESR and CRP (GCA).
-Retinal disease (age-related macular degeneration), refractive errors, cataract, corneal scarring
Presentation and investigation of Bell’s palsy
-Weakness of all ipsilateral muscles of facial expression (forehead affected)
-Post-auricular pain (may precede paralysis)
-Altered taste, dry eyes, hyperacusis
-Clinical diagnosis and serology for Lyme disease
Management of Bell’s palsy
-Oral prednisolone within 72 hours onset
-Antivirals?
-Eye lubricants, tape eye closed using microporous tape at night
Presentation of acoustic neuroma
Vestibular schwannomas- 5% intracranial tumours, 90% cerebellopontine angle tumours
-Vertigo
-Hearing loss (unilateral sensorineural)
-Unilateral tinnitus = vestibulocochlear
-Absent corneal reflex (trigeminal)
-Facial palsy/ numbness
Diagnosis of acoustic neuroma
-Urgent referral to ENT
-MRI (gadolinium-enhanced) cerebellopontine angle
-Audiometry
Management of acoustic neuroma
-Often observed initially (slow-goring, benign)
-Surgery
-Radiotherapy
Presentation of vestibular neuronitis
-Recurrent vertigo attacks (rotational) lasting hours or days
-Nausea and vomiting
-Horizontal nystagmus
-No hearing loss, or tinnitus
-Preceding viral infection
Diagnosis of vestibular neuronitis
-Clinical
-Head impulse test positive
Management of vestibular neuronitis
-Prochlorperazine
-Antihistamine
-Vestibular rehabilitation exercises
Presentation of Meniere disease
-Recurrent episodes of spontaneous vertigo
-Roaring tinnitus
-Fluctuating sensorineural hearing loss
-Sensation of aural fullness or pressure
-Nystagmus
-Positive Romberg test (swaying or falling when feet together and eyes closed)
-Episodes last minutes to hours, typically unilateral then bilateral after number of years
Diagnosis of Meniere disease
-ENT assessment
-Clinical diagnosis- at least 2 spontaneous episodes of vertigo last 20 mins to 12 hours, fluctuating hearing, tinnitus, and/or perception of aural fullness, hearing loss confirmed by audiometry (low-to-mid frequency)
Management of Meniere disease
-Inform DVLA- cease driving until satisfactory control of symptoms achieved
-Acute attacks= buccal or intramuscular prochlorperazine, betahistine and vestibular rehabilitation exercises for prevention, IV labyrinthine sedatives
Presentation of Glossopharyngeal nerve lesions
-Cough/ change to quality of voice after ineffective swallow (afferent nerve)
-Absence of gag reflex
-Loss of taste posterior third of tongue
-Sensory loss over soft palate
-Mild dysphagia
Presentation of vagus nerve lesions
-Deviation of uvula towards unaffected side
-Asymmetrical elevation of palate away from lesion
-Weak, non-explosive sounding bovine cough (inability to close glottis)
-Cough/ change to quality of voice after ineffective swallow (efferent nerve)
-Nasal speech, dysphagia
-Absence of gag reflex
-Nasal speech, hoarseness (unilateral) vs aphonia/ inspiratory stridor (bilateral recurrent laryngeal nerve palsy)
Presentation of accessory nerve lesions
-Shoulder pain and heaviness
-Difficulty or inability to raise hand overhead
-Neckline asymmetry- ipsilateral shoulder drooping, lateral winging of scapula, paresis/ atrophy of sternocleidomastoid and trapezius muscles
-Weakness during elevation of ipsilateral shoulder when shrugging
-Weakness in turning head towards contralateral side
Presentation of hypoglossal nerve lesions
-Wasting and fasciculations of tongue/ atrophy of ipsilateral tongue
-Deviation of tongue towards hypoglossal lesion
-Weakness of tongue pressing side of lesion
