Flashcards in Disorders of Equilibrium Deck (63)
True or false: dizziness may result from a disorder in any organ system
What are the four major organ systems that generally lead to the development of dizziness?
True or false: dizziness may be physiologic
What is the definition of disequilibrium?
Altered sense of balance
What are the three major inputs for equilibrium?
What part of the spinal column is responsible for proprioception?
What are the three major organ systems that can produce vertigo?
True or false: vertigo is always pathologic
How can you identify vertigo that is psychogenic in nature?
Absence of nystagmus
Psychogenic vertigo is usually seen in patients who have what conditions?
Panic disorder or agoraphobia
What is agoraphobia?
Afraid of open spaces/leaving their home
Can you have true vertigo without vestibular system involvement
Where can the lesions located with vestibular system disorders? (3)
What are the receptors for vertical motion?
Saccule and utricle
What bone houses the vestibular apparatus?
What is the position sensing apparatus within the semicircular canals?
What is the blood supply to the labyrinth?
internal auditory nerve
The endolymphatic fluid is high in what mineral? Low?
High in K
Low in Na
What is the pathway that transmits information from CN VIII?
Medial longitudinal fasciculus
What causes height vertigo?
Widening of the tiny saccular movements of the eyes d/t taller objects
What, generally, is physiologic vertigo?
Exaggerated response to normal phenomenon
What are the three HEENT exam bits that should always be obtained with a complaint of dizziness?
Which is usually pathologic and which is physiologic: jerk vs pendular nystagmus?
How is the dix-hallpike maneuver performed?
Hold patient's head at 45 degree angle (extended), and have them look to the right/left while turning their head.
How can jerk nystagmus be brought about physiologically?
have eye move toward punctum so that no cornea is seen
How is nystagmus defined: by the fast or the slow phase?:
Is there nystagmus with pts in a coma?
No--controlled by the cerebral hemispheres
What are the characteristics of peripheral jerk nystagmus in terms of:
-fatigue on repeat testing
-2-20 second Latency
-Has Positional adaptation
-Will fatigue on repeat testing
What are the characteristics of central jerk nystagmus in terms of:
-fatigue on repeat testing
-No Positional adaptation
-Little fatigue on repeat testing
Where do CN VIII nerves decussate?
In the pons
What, generally, is the BAER test?
Measuring the action potential of CN VIII as is traverses up the brain
What is the order of nerves/nuclei in the auditory pathway?
1. Acoustic nerve
2. Cochlear nerve
3. Superior olivary nucleus
4. Lateral lemniscus
5. Inferior colliculus
6. Medial geniculate
7. Auditory radiations (thalamocortical)
What are ENGs?
Electronystagmography--measuring the eye movement by detecting the changes in electrical activity whilst injecting cold water
What way does nystagmus occur with cold water injection in the ear?
Toward the side
Vertigo only with head movement = ?
Jerk nystagmus at rest/exacerbated by movement = ?
Otologic s/sx associated with vertigo most likely indicates what?
What type of nystagmus is usually found with peripheral disorders?
What is vestibular neuritis?
Inflammation of the vestibular nerve, usually of viral etiology
What is labyrinthitis?
Inflammation of the labyrinth, usually
What is Ramsey-Hunt syndrome?
Zoster infection of the labyrinth
What are the traumatic causes of peripheral vestibular disorders?
What is the classic sign of Ramsey-Hunt syndrome?
Vesicles in the ear canal
What is Meniere's syndrome?
Endolymph hydrops (too much fluid in the ear), which flows into other areas, causing damage
What is the classic triad of symptoms for Meniere's disease?
What is cholesteatoma?
Hyalinized epithelium of the middle ear
What is the bloody supply to CN VIII?
Internal auditory artery
What is the usual presentation of a labyrinthine infarction?
Sudden hearing loss
What are the associated symptoms of motion sickness?
Autonomic overtones (sweating, salivation, yawning)
What, generally, causes motion sickness?
Overstimulation of peripheral vestibular system
True or false: motion sickness may be induced by eye movements
Is BPV usually unilateral or bilateral?
What usually precipitates episodes of vertigo with BPV?
Movement of the head
What causes acoustic neuromas?
Bilateral schwannomas = ?
Vertigo that comes on at rest or worse with position changes = ?
What are the other, general, signs associated with central causes of vertigo?
CNS findings (e.g. diplopia, dysarthria, ataxia etc)
What is the arterial supply to the pons?
What is the general medication class that is used to treat central vertigo?
What are the four major classes of drugs used to treat vertigo?
What is the goal with the Epley maneuvers?
Reposition the otoconia
How can you tell which ear is affected with BPV?
Nystagmus will go to the side of the lesion