Head moves left - Fluid moves ampullopedal in L Horizontal Canal Excitatory; Pushes toward kinocilia (Stereocilia toward Kinocilia) on Left. On Right,pulls away from Kinocilia, Excitatory).
When you turn your head to the right what happens in the horizontal canals? Look at this image
1. Excitation on the right due to ampullopetal flow
2. Inhibition to the left due to ampullopetal flow?
Why is this image challenging to understand?
What determines excitation versus inhibition with this image?
VOR Cancellation: Tests for Cerebellums capability to inhibit the Vestibular Occular reflex
VOR allows the eyeballs to maintain fixation on a target while the head is moving. Test to see if VOR can be canceled via the cerebellums inhibitory input. There should be no eye motion during the test if cerebellum is working appropriately. . Seeing if pt can't maintain eyes directly on thumbs,
Head Impulse test: The ability to fixate on a target during unpredictable head movements. Wear your normal contact lenses or glasses.
Was your first attack severe vertigo, nausea, and vomiting lasting for hours?
◦Likely Vestibular Neuritis, Labyrinthitis, or Vascular Event
Do you recall the actual day and time you had your event of dizziness?
◦Vestibular Neuritis, Labyrinthitis, or Vascular Event
Do you get dizzy when rolling in bed?
Does one ear feel full immediately before or during the attack of dizziness?
◦Meniere’s disease likely
Do loud noises set off dizziness or make your eyes wobble/jiggle?
◦PLF, Superior canal dehiscence:, Arnold Chiari likely
A perilymph fistula (PLF) is an abnormal connection (a tear or defect) in one or both of the small, thin membranes (the oval window and the round window) that separate the air filled middle ear and the fluid filled perilymphatic space of the inner ear.
Vestibular and auditory symptoms and signs can result from a dehiscence (opening) in the bone overlying the superior semicircular canal of the inner ear. This clinical syndrome—superior semicircularcanal dehiscence syndrome (SSCD)—was first described by Minor and colleagues ...
Study in Vestibular Rehab