PLOD1 and pathologic nystagmus: The four separate trials of the caloric test yield four nystagmus intensity metrics, which are used as the input variables to Jongkees’ formula (JF) to calculate the asymmetry index as its output,3 which is the measure of unilateral weakness:(1)JF=((LC+LH)−(RC+RH))/(LC+LH+RC+RH)×100%