Seventy-four healthy subjects between the ages of 65 and 88 years (mean=75 years), 21 men and 53 women, underwent the caloric test. The subjects were divided into two groups; 65-74 and 75-88 years of age. The caloric test was also performed in 20 healthy young individuals 20-29 years of age as a control group.
The ears were irrigated with 20ml of ice water for 20 seconds. Caloric nystagmus was recorded by ENG with the eyes kept open in darkness.
The total number of beats, the duration of nystagmus, the maximum velocity of the slow phase and the latent time of the nystagmus were recorded.
The results in the elderly subjects were compared with the findings in the control group.
1) The caloric reaction, measured by the duration of nystagmus and maximum velocity of the slow phase, appeared to be significantly decreased in the 75-88 years age group.
2) Functional asymmetry of caloric response was revealed at the parameter maximum velocity of the slow phase in 5 subjects over 65 years of age.
3) All the members of the control group complained of definite rotatory vertigo, but 12 subjects (8.1%) more than 65 years of age had no sensation of dizziness.
4) Our investigation indicates that the caloric response is generally well preserved up to a highly advanced age.
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