In some test situations, caloric responses may be available only for one temperature; either by design or by necessity:
- Design: Monothermal screening test
- Necessity: Patient may not be able to tolerate complete bithermal caloric procedure
The Interacoustics FireWire VNG systems VN415 and VO425 now offer the Monothermal Warm Caloric Screening Test with a modified equation for Unilateral Weakness, UW%
The Monothermal Warm Caloric Screening Test uses the first two warm caloric irrigations to calculate a screening value for caloric weakness called MWST.
If the MWST value is below 15% you can omit the cold irrigations, thereby shortening the test time by 15 minutes and exposing the patient to less testing.
MWST can be calculated with compensation for spontaneous nystagmus.