Dizziness Flashcards
What is vertigo?
A sensation of movement, usually spinning
Not all dizziness is otogenic- how can pathology in the following organs lead to dizziness?
a) the eye
b) the brain
c) the CV system
a) Cataracts- impair vision. Diabetes mellitus retinopathy
b) Stress, migraine, space occupying lesion, MS
c) Cardiac arrhythmia, postural hypotension
What is the purpose of the vestibule-ocular reflex?
Allows reflex eye movements to compensate for head movements in order to keep a steady image on the retina
What is the role of the abducens nerve?
Controls movement of the lateral rectus muscle
The medial rectus muscle is controlled by which nerve?
Oculomotor
What is the clinical significance of the vestibular-ocular reflex?
Nystagmus will be seen in vestibular pathologies; most non-vestibular pathologies will not cause nystagmus
Which questions should be asked in a dizziness history?
Triggers Time course/onset Associated symptoms especially deafness, tinnitus, vomiting Alleviating factors Any current medication
What are common causes of dizziness (non-otogenic)?
Postural (Hb, Sodium, BP lying/standing)
Side effect of medication (history)
Psychogenic and interaction with imbalance
What are the core symptoms of Meniere’s disease?
Vertigo, tinnitus, aural fullness, sensorineural hearing loss
What is the hallmark of Meniere’s disease?
Fluctuating and episodic pattern of disease
How can audiometry help diagnose Meniere’s disease?
Show sensorineural hearing loss
What ENT diseases should be considered in a differential diagnoses of vertigo?
Meniere’s disease, benign positional paroxysmal vertigo, acute vestibular neuronitis
What should be excluded in any patient with unilateral deafness, tinnitus and/or facial nerve palsy? How would this be achieved?
Acoustic neuroma (vestibular Schwannoma). MRI brain scan
How is Meniere’s disease managed non-surgically?
Supportive measures- lifestyle advice: occupation, diet (avoid salt, caffeine, alcohol), stress
Therapy for tinnitus
Hearing aids
What drug might be trialled in Meniere’s disease prophylaxis?
Betahistine (anti-vertigo drug)
What more invasive treatments can be tried for Meniere’s disease?
Grommet insertion (micropressure therapy)
Intratympanic gentamicin (may cause a degree of sensorineural hearing loss)
Intratympanic steroids
Surgery
What is the most common cause of vertigo on looking up?
Benign positional paroxysmal vertigo
What is BPPV?
Attacks of vertigo triggered by head movements (such as looking up, turning in bed, getting out of bed, bending forward, moving head quickly). May be more noticeable in certain directions
What is the underlying cause of BPPV?
Displacement of otoliths from the utricle into the semicircular canal (usually the posterior canal) causing abnormal fluid displacement which continues even when movement has stopped
Which test is used to clinically confirm posterior canal BPPV?
Dix-Hallpike test. Patient sits on couch so that head will be off the end if they lie down, ask patient to turn head to 45 and warn not to close eyes if dizzy, lie the patient back as quickly as possible, hold in position and observe
What constitutes a positive Dix-Hallpike test?
Nystagmus- usually a delay of around 30 seconds
How does vestibular neuronitis present?
Prolonged vertigo (days) with no associated tinnitus or hearing loss
How does labyrinthitis differ from vestibular neuronitis?
There may be associated tinnitus or hearing loss
How are vestibular neuronitis and labyrinthitis treated?
Supportive with vestibular sedatives
Usually self limiting so if prolonged may require further investigation
In prolonged cases rehabilitation exercises may help
What proportion of migraine patients experience vertigo?
Around 25%
What disease may BPPV be confused with? What other symptoms need to present for this diagnosis to be made?
Vertebrobasilar insufficiency
Need other central neurological symptoms + vertigo, e.g. visual disturbance, weakness, numbness
Why is it uncommon for brainstem causes of vertigo to present as vertigo alone?
Brainstem nuclei and tracts are confined within a small space
Presentation of vestibular schwannoma? (4)
Vertigo
Unilateral deafness and tinnitus
Unilateral facial palsy
Unilateral loss of corneal reflex
Minimum bedside assessment of a patient with vertigo/dizziness? (6)
Eye movements checking for nystagmus, internuclear opthalmoplegia
Assessment of hearing, otoscopy
Head impulse test- test the vestibulo-ocular reflex
Hallpike manouevre
Cranial nerve examination
Cerebellar examination
How is the head impulse test performed and how should it be interpreted?
Ask patient to fix on distant object
Examiner turns patients head rapidly 15 degrees
If saccades (voluntary movement) of eyes towards target then there is a unilateral vestibulopathy on the side being tested
