Sympathetic skin response evoked by laser skin stimulation.

The objective of this study was to evoke sympathetic skin responses (SSRs) in healthy subjects using laser stimulation and to compare these responses with those induced by conventional electrical stimuli. Twenty healthy subjects were investigated. SSRs were obtained using electrical and laser stimuli delivered to the wrist controlateral to the recording site.

Pre-perceptual pain sensory responses (N1 component) in type 1 diabetes mellitus.

We investigated the integrity of the ascending pathways for pain sensitivity in the early stage of type 1 diabetes mellitus, by measuring the N1 component and the conventional N2/P2 vertex potentials of laser evoked potentials (LEPs). Brain responses to laser stimuli were obtained in 21 healthy volunteers and 21 type 1 diabetic patients, without either clinical neuropathy or electrophysiological evidence of large-fiber damage. In diabetic patients N1 and P2 latencies were prolonged and the N1 and N2/P2 amplitudes were decreased after foot stimulation.