In which pa of the semi circular canals is Calorie test based on thermal stimulation done?: (A) Lateral, (B) Posterior, (C) Anterior, (D) All of the above
Answer is A. Cold or warm water or air is irrigated into the external auditory canal, usually using a syringe. The temperature difference between the body and the injected water creates a convective current in the endolymph of the nearby horizontal semicircular canal. Hot and cold water produce currents in opposite directions and therefore a horizontal nystagmus in opposite directions Mnemonic used to remember the FAST direction of nystagmus is COWS (Cold-Opposite, Warm-Same) Cold water = FAST phase of nystagmus to the side Opposite from the cold water filled ear, Warm water = FAST phase of nystagmus to the same side as the warm water filled ear. Contralateral when cold is applied and ipsilateral when warm is applied