Vertigo and Dizziness Flashcards
What are the four characteristics of nystagmus concerning for a central cause?
Pure vertical downbeating, spontaneous pure torsional, direction change, non-fatigable
What is the old difference between vertigo and nystagmus? What are the new categories?
Vertigo = illusion of motion. Any sensation of idsorientation or movement technically qualifies
Disequillibirum = unsteady while walking
Acute (stroke)
Acute recurrent (TIA, menieres)
Recurrent positional (BPPV)
What is the actual pathophysiology of BPPV?
You have 3 semicircular canals, an utricle and a saccule on each side. In BPPV otoliths come out of utricle and go into a semi circular canal - most commonly the posterior, then horizontal.
When this happens your body gets the sense that one side of you is still moving which messes up the coordinated symetrical response, leading your body to panic and cause vertigo.
What is the pathway from your ear to coordinating movement?
Vestibular apparatus -> CN 8 -> brainstem below the pons -> vestibular nucleai of the brainstem -> cerebellum -> the medial longitudenal fasiculus and vestibular spinal tract -> motor neurons supply the extremities
If working youlr body can sense where you are in space and can keep your eyes steady while also coordinating smooth movements
If its not you cant keep a steady axis and make erratic movements
What causes nystagmus?
A problem with synchronized vetibular information causes asymetric stimulation of medial and lateral rectus muscles
You get slow movement towards side of stimulus and then fast cortical correction back (this is the directon of the nystagmus, the one that the brain says GET BACK HERE)
What vessel is typically affected by vertebrobasillar insuffciency?
PICA and AICA
Supplies the medulla, pons, midbrain and cerebellum
(Like NSTEMI, see with atherosclerotic disease)
What should peripheral vertigo not have?
Syncope or a change in mentation
What peripheral cause classically has tinnitus?
Menieres disease
What is subclavian steal? Why
Subclavian arery stenosis proximal to the vertebral artery. It lead to central cause of vertigo because when the subclavian needs more blood you actually get retrograde flow from the vertebral circulation to feed to subclavian. Get arm fatigue in addition to central vertigo.
What is a red flag for periplymphatic fistula? Why?
What are 3 other things that can give you fluid in your middle ear?
Perforated or scared ear drum - implies previous trauma. Recall this fistula is a hole from the inner ear to the middle ear that allows fluid from inner ear to leak into middle ear.
Infection, cancer, blocked eustachian tubes, bartrauma from ascent
Why is spontaneous nystagmus worrisome?
Nystagmus is proportional to the degree of vestibular dysfunction. If spontaneous its probably severe vs more mild or asymptomatic
You stand someone up in bed - are there any clues to central vs peripheral there?
Central wont be able to stand
Peripheral can stand but need support (veer toward side of lesion)
What is ataxia? What is a cerebellar gait?
Ataxia - lack of voluntary muscle movement coorindation
Cerebellat gait
Wide base (cant compensate with tiny movements to keep upright if narrow)
Unsteady movements - smoothness comes from cerebellum and you lose it. Worse when turning on a dime
Irregular steps - same as above
Lurching from side to side
Trunk tremor
Outline the nystagmus seen with Dik Hallpike
*make sure when you are preforming this you wait enough time for slow onset and then resolution. Same with Epley
Dik Hallpike is negative or positive bilaterally - what might you try next and why?
Supine roll test - looking for reproduction of symptoms and horizontal nystagmus (two types to floor and away)
If positive proceed with BBQ roll test for treatment
