Neuro- disorders of Equilibrium Flashcards
what is equilibrium?
ability to maintain orientation in the body and its parts in relation to external space
what is disequilibrium? what is it confused with? what are the 2 ways it presents clinically?
inability to maintain orientation of the body, often confused w/ syncope/presyncope.
2 ways it presents: vertigo and ataxia
what is syncope?
light-headed, giddy, faint w.out illusion of movement
- decreased supply of blood, O2 or glucose to brain
- more vascular than neuro problem
- presyncope –> syncope when LOC
- “dizzy” is presyncope if not vertigo
how many adults will have syncope?
1/3
2 components of syncope
- cardiac (more often ): mostly vasovagal: standing up, blood pools in legs, supposed to get reflex inc in HR and vasoconstriction so blood goes to the head. (carotid response to drop in BP)
- neurologic: excess vagal stim, bradycardia, vasodilation - no blood to head.
what is orthostatic hypotension?
BP drops too much and cant get inc in HR fast enough
-in eldery, DM, on diuretics, alpha blockers, anticholinergics
what is vasomotor/vasovagal syncope?
most common type of syncope
-sudden inc vagal tone (stress or painful situation)
postmicurition (defecation) syncope
- inc vagal tone from urination causes syncope
- defecation/constipation = inc intrabdominal pressure = carotid body stim = pass out
what does low vasal tone mean?
Vagal tone is a measure of cardiovascular function that facilitates adaptive responses to environmental challenge. Low vagal tone is associated with poor emotional and attentional regulation in children and has been conceptualized as a marker of sensitivity to stress
syncope vs seizure
syncope: no post-ictal state, only mild symptoms of disorientation, no confusion/fatigue
not well explained syncope…. what tests will you run?
- ECG (esp if it’s their first one)
- autonomic testing- tilt table test (looks for orthostatic hypotension)
- electrophysiologic studies- invasive, to see electricity of heart
Va state driving recommendations after syncope?
no driving 6 months, up to pt to report
what is ataxia? what do you need for a stable stance?
lack of coordinated movement
- intact cerebellum, vestibular system, intact sensation (vision and proprioception)
- cerebellum is most important component
vestibular ataxia.. what causes it and how do you test for it?
same lesions that cause peripheral vertigo- now have abnormal stance/gait
- romberg test
- mild vestibular ataxia w/ earache (pressure on middle ear –> pressure on inner ear)
what is cerebellar ataxia?
lesions of cerebellum or its connections
- greatest abnormal movements w/ irregular rate, rhythm, amplitude or force of voluntary movements
- cant stand eyes open or closed
- wide gait
what is sensory ataxia?
lose proprioception = ataxia
- deficit most often w/ bilateral peripheral nerves or posterior columns of spinal cord
- romberg- close eyes and fall
- decreased joint position and vibratory sense (steppage gait)
3 abnormalities w/ cerebellar disease
- hypotonia: poor posture, limbs easily moved with small force
- incoordination: accel and deceleration of movement decreased, jerky appearance, see best in walking
- eye movement- nystagmus, gaze paralysis or dec. pursuit movements
nystagmus with ataxia…
vestibular= nystagmus cerebellar= usually w/ nystagmus sensory = none
vertigo is classified as …
peripheral or central- determines how you treat it
- peripheral: inner ear or CN 8
- central: brainstem or cerebellum (lesions)
nystagmus w/ vertigo…peripheral vs central
peripheral- horizontal
central- may be vertical, unidirectional, multidirectional and may be different in each eye
BPPV
otoliths in semiCs
- always assoc. w/ horizontal nystagmus
- txt: antiemetics, repositioning, habituation
triad of menieres
vertigo, hearing loss, tinnitus
also…drop attacks when unable to stand (Ataxia)
peripheral vs central vertigo
central: hypereflexive- inhibition is off , hearing loss rarely present, less severe vertigo
what three things to ask the “dizzy” pt
how did it happen? when did it occur? describe the sensation…