ENT - vertigo Flashcards
What is vertigo?
a sensation that there is movement between the patient and their environment.
Feeling like they are moving or that the room is moving
Often a horizontal spinning sensation
What is the pathophysiology of vertigo?
A mismatch between the sensory inputs of vision, vestibular system and proprioception
What makes up the vestibular system? How does it work?
3 semicircular canals filled with endolymph orientated at different angles
Cilia detect small changes in the shifting fluid - these are located in the ampulla
The sensory input of shifting fluid is transmitted to the vestibular nucleus in the brainstem and the cerebellum via the vestibular nerve to inform the brain that the head is moving
Vestibular nucleus sends signals to CN3,4,6 (control eye movements), the thalamus, spinal cord and cerebellum
Cerebellum is responsible for co-ordinating movements throughout the body
Central vs peripheral vertigo - what is the pathology in each
Peripheral vertigo - a problem usually with the vestibular system
Central vertigo - a problem with the brainstem or cerebellum
Vestibular (peripheral) causes of vertigo - main 4
BPPV
Meniere’s disease
Vestibular neuronitis
Labrynthitis
What is BPPV? Pathophysiology?
Calcium carbonate crystals called otoconia that become displaced into the semicircular canals
They may be displaced by a viral infection, head trauma, ageing or without a clear cause.
The crystals disrupt the normal flow through the canals and therefore disrupt the function of the system.
How does BPPV present and why?
Positional vertigo - as movement is required to confuse the vestibular system
Improved on staying still
Nystagmus
What causes Meniere’s disease?
Excessive buildup of endolymph in the semicircular canals causing increased pressure
This disrupts the sensory signals
Presentation of Meniere’s disease
Attacks of vertigo last several hours with episodes of nystagmus and they arent triggered by positions
Symptoms of hearing loss, tinnitus and vertigo
Sensation of fullness in the ear
What is acute vestibular neuronitis?
Inflammation of the vestibular nerve
Usually attributed to a viral infection but this may be asymptomatic
Disruption to the nerve causes mismatch of signals causing vertigo
History of acute onset of vertigo that lasts several weeks before gradually resolving
Other causes of peripheral vertigo
Trauma to the vestibular nerve
Vestibular nerve tumours - acoustic neuromas
Otosclerosis
Hyperviscosity syndromes
Herpes zoster infection (often with facial nerve weakness and vesicles around the ear - Ramsay Hunt Syndrome)
How to differentiate between vestibular neuronitis and labrynthitis?
Labyrinthitis is inflammation of the structure of the inner ear - usually attributed to a viral infection
Labyrinthitis can cause hearing loss which does not occur in vestibular neuronitis
Most common central causes of vertigo
Posterior circulation infarction (stroke)
Tumour
Multiple sclerosis
Vestibular migraine
What symptoms may suggest a posterior circulation stroke?
Sudden onset
May be associated with other symptoms e.g. ataxia, diplopia, cranial nerve defects or limb symptoms
What symptoms may suggest a tumour causing vertigo?
Tumours in the cerebellum or brainstem will have gradual onset with associated symptoms of cerebellar or brainstem dysfunction
What symptoms may suggest MS causing vertigo?
Relapsing and remitting symptoms
Other associated features of MS e.g. optic neuritis or transverse myelitis
What symptoms may suggest vestibular migraine causing vertigo?
Symptoms lasting minutes to hours
Often associated with visual aura and headache
Attacks may be triggered by - stress, bright lights, certain foods, dehydration, menstruation
Examinations that can be done in vertigo assessment
Ear examination
Neurological examination
CV examination (CV causes of dizziness e.g. arrhythmias, valvular disease)
Cerebellar examination
Special tests:
- Romberg’s test
- Dix-Hallpike manoeuvre
- HINTS examination
How to perform a cerebellar examination?
DANISH
D- Dysdiadochokinesia A- Ataxic gait - ask patient to walk heel to toe N- nystagmus (as in HINTS exam) I - intention tremor S - slurred speech H - heel-shin test
What is Romberg’s test?
Screens for problems with proprioception or vestibular function
First patient stands with eyes open and then eyes closed
Observer standing nearby to assist if the patient becomes imbalanced
What is the HINTS examination and how do you perform it?
HI - head impulse:
- Check no neck pain
- Ask the patient to sit and look at your nose
- Rapidly jerk head 10-20 degrees in one direction and then slowly return to centre
- Repeat on other side
- Normal/central cause of vertigo - the patient’s eyes stay fixed on the nose
- Peripheral cause of vertigo, the eyes will saccade (rapidly move back and forth) to eventually focus back on the nose
N - nystagmus:
- Ask the patient to look left and right without focusing on any object
- Unilateral/horizontal nystagmus - more likely to be peripheral origin of vertigo
- Bidirectional nystagmus/vertical - more likely central origin
TS - test of skew
- Also called the alternate cover test
- Sit patient upright and ask to focus on your nose
- Cover one of the patient’s eyes
- Quickly move to cover the other eye and observe the uncovered eye for any vertical/diagonal movement
- Repeat the other side
- The eyes should remain fixed on the examiner’s nose
- If there is vertical correction, suggests a central cause of vertigo
Management of vertigo
Central vertigo - referral for further investigation e.g. CT/MRI head to establish cause
Peripheral vertigo STM of Sx - Prochlorperazine
- Antihistamines e.g. cyclizine
Specific treatments:
- Betahistine in Menieres to reduce attacks
- Epley manoeuvre in BPPV
- Avoidance of triggers, triptans and general migraine prophylaxis in vestibular migraine
