Vertigo Flashcards
What is vertigo?
- Dizziness/sensation of motion with central (brain) or peripheral (inner ear) origins
- Either self-motion or motion of environment
S/s of vertigo?
- N/V
- Postural instability and gait
~ More often in vertigo of central origin (lesion in cerebellar region) - Pallor, sweating
- Tinnitus, deafness
- Headache
- Photophobia
~ When associated with migraine - Nystagmus
~ Horizontal, vertical, rotary
What is the pathophysiology of vertigo?
- CNS receives signals from both left and right labyrinths
~ Compares the signals with one another
~ When still, signals are balanced
~ When in motion, r/l labyrinths are alternately excited and inhibited
What are the vestibular labyrinths?
- Relays information to CN 8 from brainstem -> cerebellum -> ocular motor nuclei and spinal cord
- Vestibuloocular connections: coordinated eye movements
- Vestibulospinal pathways: Upright posture
- Cerebellar connections: Modulates ^^ activities
- Semicircular canals: sense angular motion
- Otolith organs: sense linear motion
- Vertigo suggests abnormality of semicircular canals or CNS structures
How do you diagnose vertigo?
- History taking (single/recurrent episodes, duration)
- Aggravating and provoking factors
- PmHx
~ Hx of migraine attacks
~ Stroke risk factors
~ Family history
~ Medication (aminoglycosides, phenytoin) toxcity - Physical examination
~ Central vs peripheral causes of vertigo
~ Types of nystagmus
~ Abnormal balance and gait
~ Neurologic examination
~ Hearing tests (to rule out deafness)
~ Caloric tests - Diagnostic tests
~ MRI (suspected of central)
~ CT scan not really used as it is less sensitive
~ Electronystagmography (ENG) (electrodes to record eye movements)
~ Videonystagmography (VNG) (video camera to ^^)
~ Audiometry (to detect hearing loss)
What are the types of hearing tests?
- Rinne
- Weber
Clinical features of central vs peripheral vertigo?
1) Nystagmus
- (P) Unidirectional and fast towards normal ear
- (P) Horizontal vs (C) Any direction
- (P) Suppressed
- (P) Absence of other neurologic signs
- (P) Unidirectional instability but walking is preserved vs (C) Severe instability and falls
- (P) Deafness or tinnitus may be present
What are the peripheral causes of vertigo?
1) Benign Paroxysmal Positional Vertigo
2) Vestibular neuritis
3) Meniere’s disease
4) Herpes zoster
5) Labyrinthitis
What is benign paroxysmal positional vertigo?
- Most common
- Spinning sensation when tilting the head upwards, or tuning in beds
- Occurs very briefly
- Due to calcium debris within the posterior semicircular canal
~ Upset balance stimulates nerve cells in the canals
What is vestibular neuritis?
- Viral or postviral inflammatory disorder
- Affects 8th cranial nerve (vestibulocochlear)
- Severe with rapid onset
What is Meniere’s disease?
- Excess endolymphatic fluid pressure in ear causes dysfunction
~ Severe vertigo
~ Tinnitus
~ Ear fullness - Often associated with N/V and disabling imbalance
- Spontaneous episodes can lasts mins-hours
How does herpes zoster cause vertigo?
- Activates latent herpes zoster
- Hearing loss, ipsilateral facial paralysis and ear pain
~ Dermatological rash and neuritis with vesicular regions
What is labyrinthitis?
- Inflammation of the inner ear labyrinth
- Due to infx, drug toxicity, trauma, tumor
What are the causes of central vertigo?
1) Brainstem ischemia
2) Cerebellar infarction and hemorrhage
3) Multiple sclerosis
4) Epileptic vertigo
5) Vestibular migraine
What is brainstem ischemia?
- Due to the occlusions in vertebrobasilar arterial system
- May be caused by TIA
