Vertigo Flashcards
Discuss pathophys of vertigo
The maintenance of equilibrium and awareness of the body in relationship to its surrounding depend on the interaction of the visual proprioceptive and vestibular systems. Input from these three systems is connected to the cerebellum by way of the vestibular nuclei in the brainstem.
Any disease that causes a mismatch of information of information from any two of these systems may give rise to symptoms of vertigo
Vestibular apparatus helps maintain head position and stablize head movement. It is housed in the inner ear or labyrinth which lies embedded in the petrous portion of the temproal bone. It consists of three semicircular canals and two otolithic structures (utricle and the saccule) THe canal provide information about movement and angular momentum whereas the utricle provides information about head tilt and linear acceleration. The left and right vestibular apparatus are paired and normally work in consert with inner disease the resting discharge or the discharge stimulated by motion can be altered in one ear leading to a mismtach in response and in the perception of vertigo.
Impulses leave the vestibular appraratus by the vestibular part of the acoustic nerve (CN 8) enter the brainstem just below the pons and anterior to the cerebellum proceed to the four vestibular nuclei of the brainstem and to the cerebellum. From there impulses travel along two pathways that contirbute to clinical manifestation of vertifo
1) medial longitudinal fasciculus
2) vestibulospinal tract which connect to the mtoro neurons and supplly the muscles of the extremities.
Connection between the vestibular nuclie and the autonomic system account for perspiration nasuea and vomiting that commonly accompany an attack of vertigo
Discuss nystagmus
Occurs when the synchronized vestibular information becomes unbalanced. Typically it results from unilateal vestibular disease which causes assymmetrical stimulation of the medial and lateral rectus muscles.
This unopposed activity causes a slow movement of the eye towards the side of the stimullus regardless of the direction of deviation of the eyes. Then the cerebral cortex corrects for these eye movements and rapidly brings the eye back to the midline only to ahve the process repeat. By convention the direction of the nystagmus is denoted by the direction of the fast “cortical” component
Discuss differential central from peripheral nystagmus
Peripheral
- unidirectional - fast component towards the normal ear
- never reverses direction
- Horizontal with a torsional componenet - nevere pourly torisonal or vertical
- Suppressed with visual fixation
Central
- Sometimes reverses direction when aptient looks in the direction of the slow componenet
- can be any direction- purely vertical or torsional nystagmus is a central sign
- Not supressed with visual fixation
Peripehral other
- Postural instability is usually unidirectional and walking is preserved
- Deafness or tinnitus may be present
- nil other periperhal neruology
Central other
- Severe instability often without ability to walk
- usually nil deafness or tinnitus assocaited
- other neurology often present
Discuss disequilibrium
Occurs due to disruption between the senosry inpurs and motor outpurs and this often results in an unsteady gait. Usually a disease of older adults as there is an age related decline in the ability of the CNS to process sensory inputs as well as a decline in control of postural reflexes. Often exacerbated by unfamiliar surroudning uneven ground or poor lighting
Cervical spondylosis is a common cause and leads to spinal cord meyloapthy
Discuss distinguishing vertigo from other types of dizziness
The spinning quality of vertiginous sensation is notoriously unreliable and cannot be used to exclude vestibular disease,
Time course
- vertigo is never continuous for more than a few week,
- Even when vesitbular lesion is permanent the CNS adpats to the defect so that vertigo subsides over several weeks,
- Constant dizziness lasting months is usually psychogenic not vestibular
- need to specify if patients means constant or recurrent
- Acute prolonged severe vertigo (vestibular neuronitis, stroke), recurrent spont attacks (Meniere disease, vestibular migraine), recurrent positionally triggered attacks (BBPV), chronic persistent dizziness (psycho or cerebella ataxia)
Provoking factors
- certain types of vertigo are spontaneous
- Others are precipirated by maneuvers that change head position or middle ear pressure
Aggraviting factors
- all vertigo is made worse by moving the head
- this is a useful feature for distinguishing vertigo from other forms of dizzness.
- if not worse with head movement is likley another cause of dizziness
Associated signs and symptoms
- vertigo whether central or peripehral is generally accompanied by nystagmus and postural instability
- Hearing loss is very suggesitve of a peripheral cause of vertigo but their absence dues not exclude peripheral causes
- peripehral causes do not alter mentition
List DDX for central and peripheral vertigo
Peripheral
- BPPV
- Vestibular neuritis hearing preserved/labryinthitis (hearing loss)
- Meniere’s disease
- foreign body
- acute OM
- perilymphatic fistula
- Trauma
- motion sickness
- acoustic neuroma
Central causes
- Vertebral basilar artery insufficiency
- Cerebella haemorrhage
- Tumor
- Migranous vertigo
- MS
- Post traumatic injury
- Infection
- Temporal lobe epilepsy
- Subclavian steel
Give history points to DDX of peripheral causes of vertigo
Peripheral
1: BPPV
- Short lived (typically less than 30 seconds) positional, fatigable episoddes more often in older adults
- Positive Hallpike
2) Vestibular neuritis/labyrinthitis
- Vertigo may develop suddenly or evolve over several hours usually increasing in intensity for hours then gradually subsiding over several days but can last weeks
- Can be worsened with positional change
- somtimes history of viral infection precedes attack]
- highest incidence is found in third and fifth decades
- Spont nystagmus beating away from the side of the lesion may be present for the first few hours
- positive HIT
- Hearing loss for labyrinthitis not for vetibular neuroitis
3) Meniere’s disease
- recurrent episdoes of severe rotational vertigo usually lasting hours
- onset abrupt
- attacks may occur in cluster
- long symptom free remission
- posiitonal nystagmus is not present
- hearing loss
Give history points to DDX of central causes of vertigo
1) Vascular disorders
a) Vertebrobasilar insufficiency
- should be considered in any patient of advanced age with isolated new onset vertigo wihtout an obvious causes. More likley with a history of atherosclerosis
- Can occur with neck trauma
- Assocaited with dysarthria, ataxia, weakness, numbness, double vision, tinnitusb
B) cerebellar haemorrhage
- sudden onset of severe symptoms
- headache vomiting, ataxia
- ipsilateral 6th nerve palsy
C) occlusions of posterior inferior cerebellar artery
- Vertigo associated with significant neurological complaints
- Loss of pain and temperauter sensation on the side of the face ipsilateral to the lesion and on the contralateral body
- paralysis of the palate pharynx and larynx (bulbar muscle weakness)
- Horners - ipsilatearl to the lesion
- Respiratory dysfunction
- Autonomic dysfunction
2) Head trauma
- symptoms begin with or shortly after head trauma
- Positional symptoms most commmon type after trauma
- self limited symptoms that can persist weeks to months
3) Migrainous vertigo
- vertigo attacks can occur during the ehadache but often occur during the headache free interval
- no residual neurological or otologic signs are present after attack
4) MS
Discuss Hallpike and how the maneuver is performed
Confrims the diagnosis of posterior cannal BPPV the most common variant.
Should be reserved for those with suspected positional vertigo and caution should be exerccised in performing it in patients with acute vestibular syndrome (acute and constant) whos main differential is vetibular neuritis and stroke.
Testing in these patient can lead to false positive and false labelling of peripheral cause
Performed with the patient sitting up- the head is than turned to 45 degrees and the patient is moved supine with head overlying gurney - patient is asked about vertigo and nystgmus is looked for
-in classic posteiror canal BPPV the nystagmus usually last 5-30 seconds and is combined upbeating and ipsilateral torsional
-THe patient is than broguth back to seating and the head is turned to the other side
In general only one side should be positive
-Assuming single side the downward ear on a positive hallpike is the effected ear and should be started wiht when doing Eplys
Discuss finding of classic positive hallpike
1) Latency
- delay in nystagmus and vertigo once in head haning position
- approximately 3-10 seconds although delay can take up to 30 seconds on rare occasions
2) reproduction of vertigo symptoms in head haning position
3) upbeat (fast phase toward forehead) and torsional (usually toward the downward ear) nystagmus
4) Vertigo and nystagmus escalates in head hanging position then slowly resolves over 5-30 seconds
5) nystagmus and vertgio may reverse direction when patient returns to sitting
6) Nystagmus and vertigo decrease wiht repeated testing (fatigue)
Discuss the supine roll test
If hallpike is -ve or seems to be positive bilaterally can use this test to test for horizonta canal
- The pateint starts in supine position and unlike the Hallpike the head does not need to verhang the edge of the gurney
- the head is then turned 90 degrees to each side - with a positive test the patient will have reporoduction of symptoms and horizontal nystagmus to the effected side
- the nystagmus will change direction but this is with change in head position and not soley on gaze so is not concerning for central causes
Describe Epilys
Can be curitive in posterior canal BPPV
If right sided positive the following example is correct
Start with hallpike
Than quickly rotate head to contralateral side with right ear upward - held for 30 seconds
patient than rolls 90 degrees onto left side with nose angled toward the floor hold for 30 seconds
patient is rapidly lifted into sitting position - entire sequence repeated until no nystagmus can be elicited
Discuss head impulse test
Used to diagnose vestibular neuritis and labyrinthitis
The physician stands face to face with the patient and placed both hands on the side of the patient head
The patient stares at the examiners nose while the examiner rapidly turns the patients head approximatl 10 degrees to one side
Normally the patients eyes should keep focus on the examiners nose. If there is a vestibuar nerve problem the eyes will temporarily move loan with head and a corrective saccade will be present
Discuss test of Skew
The test involves covering one eye and seeing if there is a vertical shift in the eye when uncovered. Brainstem and cerebellar lesions somtimes cause a slight skew deviation
