Term
Things to remember:
-___ ear(s) are involved simultaneously
-Test can be influenced by ___ of patient
-Cannot be used to isolate one peripheral system from the other for evaluation but can be used to suggest possible ___
-Just as in VNG, ___ nystagmus is the response of interest |
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Definition
| Both; alertness; localization; jerk |
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Term
Things to remember:
-___ component of eye velocity of the VOR is the portion of eye movement for which velocity is calculated
-Velocity rotation of the head less than ___ seconds is a direct response of VOR from the vestibular end organ
-For longer constant velocity rotations, compensatory eye movements up to and beyond 10 seconds (to around 15 seconds) is a measure of a ___ mechanism (velocity storage)
-___ lesions affect the velocity storage mechanism |
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Definition
| Slow; 10; central; Brainstem |
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Term
| What are the 4 outcome parameters used in a typical rotary chair analysis? |
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Definition
| Spectral purity, phase angle, gain, and symmetry |
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Term
| Compares the quality of sinusoidal nature of the chair movement to that of the eye movement |
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Definition
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Term
Spectral Purity:
-Not one of the ___ outcome measures
-Increases or decreases the operator’s ___ in the other three outcome measures ›
-Looks at strength of ___ ___ of the sinusoidal eye movement and chair movement–closer to 100% more reliable results of the three principal outcome parameters |
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Definition
| principle; confidence; fundamental frequency |
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Term
| Principle outcome parameter that signals abnormality of chair findings |
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Definition
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Term
Phase Angle:
-Relationship between head and ___ movement
-Difference between when the head velocity trace is at its peak velocity and when the eye velocity trace is at its peak
___ ___ eye velocity |
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Definition
eye; slow component
[image] |
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Term
Phase-Peripheral Lesion:
-Stable maximum peripheral vestibular lesion, ___ degrees at 0.01 Hz
-Acute change in unilateral lesion or bilateral lesion, ___ ___ of greater than or equal to 69 degrees at 0.01 Hz
-Severe bilateral peripheral pathology (hypofunction) gain of virtually zero – no ___ ___
-Partial bilateral hypofunction will show abnormally ___ phase degrees at frequencies affected |
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Definition
| 69; phase angle; measurable phase ; high |
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Term
| ___ is how much eye movement is happening |
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Definition
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Term
Gain:
-___ divided by ___
-___ component velocity eye movement divided by velocity of ___ movement
-Head must be coupled to the chair to avoid “___”
-Slippage occurs when there is a ___ for head movement at higher frequencies of rotation. Seen as ___ in phase lead and ___ in gain only at higher frequencies (this is not
indicative of a pathologic process) |
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Definition
Output; input; Slow; head; slippage; lag; increase; decrease
[image] |
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Term
Gain:
-Measure of overall ___ at frequency being tested
-Reflects responsiveness of right and left ___ canals in an additive manner
-Unusual to see a decrease in ___ for a unilateral peripheral vestibular system lesion
-May see a decrease in gain after an ___ unilateral peripheral insult |
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Definition
| responsiveness; horizontal; gain; acute |
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Term
Gain – Compensation:
- Short-term bilateral ___ in responsiveness in an effort to control acute symptoms
-Gain does not reflect differences in the response from right versus left – measured by ___
-Bilateral hypofunction can cause severely ___ gain up to normal range gain depending on extent of lesion in the horizontal canal |
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Definition
| reduction; symmetry; reduced |
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Term
Gain - Central:
-Reflects possible central vestibulo-cerebellar disorders
-Most likely when gain is abnormally ___
-Cerebellar damage can release the governor over the maximum output and allow gain to rise to better than __
-Should also see ___ caloric response and ___ oculomotor |
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Definition
| high; 1; hyperactive; abnormal |
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Term
Percentage difference between the peak slow component eye velocity generated to the left from rotation to the right, and
the peak slow component eye velocity to the right from rotation to the left |
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Definition
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Term
| As long as no other central signs, asymmetry (abnormal symmetry) is interpreted like ___ ___ from caloric testing |
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Definition
| directional preponderance |
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Term
Symmetry:
-Abnormal symmetry suggests an asymmetry in the ability to ___ the right versus left horizontal canals and the asymmetry has not yet been ___ for at the level of the vestibular nuclei
-___ to stimulate nystagmus in one direction versus the other |
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Definition
| stimulate; compensated; Easier |
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Term
Symmetry:
-Important note when talking about directional preponderance of caloric testing we are talking about the ___ component; in the rotary chair the measurement are made from the ___
component
-EX: a right beating directional preponderance from the caloric, would show a ___ greater than ___ asymmetry in rotary chair |
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Definition
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Term
| If time constant is greater than 30 seconds, the concern would be for ____ involvement |
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Definition
| central vestibulo-cerebellar |
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Term
| The time it takes for the peak slow component velocity eye to decay to 37% of the peak value after acceleration |
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Definition
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Term
Gain (Step Test):
-No established ___ range
-___ or above as normal and percentage difference of less than 30% (between directions)
-Indicative of ___ lesions with asymmetry
-Values at 1.0 or above suggest ___ system or ___ involvement – would need to be reinforced with hyperactive response on caloric or ocular motor or SHA gain |
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Definition
| normative; .4; unilateral; hyperactive; cerebellar |
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