Measurement, analysis, and modelling of the caloric response. 2. Evaluation of mental alerting tasks for measurement of caloric-induced nystagmus.
Management of the patient's level of arousal is one of the most important variables in obtaining consistent and strong caloric responses. The patient may suppress the caloric response and/or exacerbate beat-to-beat variability if some type of mental alerting (MA) task is not used to focus the patient's attention from his or her dizziness. An experiment was undertaken to evaluate simple MA tasks in terms of associated caloric response strength and variability. Warm caloric responses were measured while each of 10 normal subjects performed eight different MA tasks. The mental exercises included two math tasks, two quizzing tasks, two hand-motor tasks, and two alphabet tasks. One of the tasks in each complementary pair required the subject to interact with the examiner throughout the caloric response. Minimal or no interaction was required for the companion task. The relative ordering among the eight MA tasks was compared in terms of total sum of ranks, summed across 15 performance measures taken from caloric response indices. The highest-ranked altering task was an exercise requiring subjects to name or list local cities, states in the U.S.A., colors, etc. The lowest-ranked tasks were backward counting exercises and reflexive quizzing, which are the traditional tasks used in the clinic.
Formby
C
C
Department of Otolaryngology-Head & Neck Surgery, John Hopkins University School of Medicine, Baltimore, MD.
Kuntz
L A
LA
Rivera-Taylor
I M
IM
Rivera-Mraz
N
N
Weesner
D R
DR
Butler-Young
N E
NE
Ahlers
A E
AE
D001143:Arousal / Q000502:physiology*; D002150:Caloric Tests / Q000379:methods*; D005069:Evaluation Studies as Topic; D006801:Humans