No abstract

Heterotopic noxious conditioning stimulation (HNCS) has been thought to give access to the diffuse noxious inhibitory controls (DNIC) in man, which can be activated in wide-dynamic-range neurons by noxious stimulation from remote areas of the body and form the neurophysiological basis of the phenomenon 'pain inhibits pain'. The latter phenomenon suggests that the subjective experience of pain is a prerequisite for an inhibitory action. The necessity of using painful stimuli as conditioning and as test stimuli to produce inhibitory effects was investigated in the present study, using a HNCS paradigm. Twenty young men received conditioning stimuli created by tonic heat at painful and non-painful levels, using either hot water (hand) or thermode (forearm). The test stimuli were phasic heat stimuli (thermode) at painful and non-painful levels applied to the cheek. Only painful but not non-painful heat as conditioning stimulus increased the heat pain threshold and decreased the ability to discriminate between painful heat of different intensities. These two findings are in accord with an inhibitory effect depending on a painful conditioning stimulus. However, the intensity ratings of the test stimuli indicated inhibitory effects of the conditioning stimuli also upon non-painful levels. Furthermore, non-painful heat as conditioning stimulus also appeared to be capable of decreasing the ratings of the test stimuli at painful levels. The latter two findings suggest: (i) that very strong but subjectively still non-painful stimulation can trigger pain inhibitory effects and (ii) that also subjectively non-painful stimuli are affected by inhibitory influences during HNCS.

This study reports the psychometric properties of a 45-item diabetes-specific questionnaire, the Questionnaire on Stress in Patients with Diabetes--Revised (QSD-R), a modified and shortened version of the QSD (G. Duran, P. Herschbach, S. Waadt, A. Zettler, & F. Strian, 1995). The QSD-R was filled out by 1,930 individuals with insulin-dependent diabetes mellitus and noninsulin-dependent diabetes mellitus. Eight consistent scales were identified (values of Cronbach's alpha: .69-.81). The test-retest reliability for the total score after a 5-week interval was rtt = .63. The results provide evidence for the reliability and validity of this instrument.

No abstract

Autonomic variables have been recommended as measures of the affective-motivational component of the pain response in objective algesimetry. In the present study components of heart rate responses to painful heat stimuli and their relation to stimulus and sensation variables were analyzed. Twelve healthy subjects served. Sixty phasic stimuli of varying temperatures above and below pain threshold were delivered through a Marstock thermode in 1 session. Heart rate, respiration, and subjective stimulus ratings were recorded simultaneously. Phasic heat stimulation above and below pain threshold induced a tonic increase of the heart rate lasting up to more than 20 sec. High intensity stimulation generated steeper rises and greater mean increase than low intensity stimulation. In general, heart rate responses were more closely related to subjective sensation than to stimulus intensity. However, differential temporal analysis demonstrates that, until about 3 sec after stimulation, the autonomic response is determined solely by stimulus temperature, whereas, after approximately 6 sec, it is related only to subjective judgement. Accordingly, the heart rate responses reflect both a brief nocifensive reflex induced by the sensory component and, subsequently, a longer-lasting response which seems to be related to affective and/or cognitive evaluation. This separation of different stages of pain-processing by an autonomic indicator may be useful in clinical algesimetry.