Age-related changes in laser-evoked potentials following trigeminal and hand stimulation in healthy subjects
M de Tommaso1, K Ricci1, A Montemurno1
1Department of Basic Medical Science, Neuroscience and Sensory System (SMBNOS), Neurophysiopathology of Pain Unit, University of Bari Aldo Moro, Bari, Italy.
Objective:
This study aimed to evaluate age-related changes in laser-evoked potential (LEP) features, including habituation, via trigeminal and hand stimulation in a large group of healthy volunteers.
Methods:
We recorded the LEPs by right-hand stimulation in 237 healthy subjects and by stimulation of the right supraorbital zone in 170 cases. The subjects ranged in age from 7 to 72 years and were divided into six groups by age.
Results:
At the trigeminal level, the N2 and P2 latencies were significantly shorter and the N2-P2 amplitude was significantly larger in the 7-17 age group than in the other groups. The N2-P2 amplitude of the responses evoked by hand stimulation was significantly larger in the 7-40 age range than in the older subjects. The N1 amplitude and latency were not significantly different among the groups. The N2-P2 habituation increased with age, but no significant changes among groups were revealed by the Bonferroni test.
Conclusions:
Trigeminal vertex LEPs have greater amplitudes and appear earlier in children, while a progressive age-related amplitude decrease characterizes the N2-P2 waves associated with hand stimulation. The N2-P2 habituation increases in older people. The N1 latency and amplitude seem to remain stable during ageing and are therefore potentially reliable and useful patterns for nociceptive system examination.
Significance:
Standardization of age-related changes in trigeminal and hand LEPs is possible and should improve their reliability in the objective assessment of pain pathways.
