Stephen W. Harkins

A comparison of pain measurement characteristics of mechanical visual analogue and simple numerical rating scales.

&NA; Numerical rating scales and mechanical visual analogue scales (M‐VAS) were compared for their capacity to provide ratio scale measures of experimental pain. Separate estimates of experimental pain sensation intensity and pain unpleasantness were obtained by each method, as were estimates of clinical pain. Orofacial pain patients made numerical scale and VAS ratings in response to noxious thermal stimuli (45–51°C) applied for 5 sec to the forearm by a contact thermode. The derived stimulus‐response function was well fit as a power function only in the case of sensory M‐VAS. The power function derived from sensory M‐VAS ratings predicted temperatures chosen as twice as intense as standard temperatures of 47°C and 48°C, thereby providing evidence for ratio scale characteristics of M‐VAS. The stimulus‐response function derived from sensory numerical ratings differed from that obtained with M‐VAS and did not provide accurate predictions of temperatures perceived as twice intense as 47°C or 48°C. Both M‐VAS and numerical rating scales produced reliably different stimulus response functions for pain sensation intensity as compared to pain unpleasantness and both provided consistent measures of experimental and clinical pain intensity. Finally, both mechanical and pencil‐and‐paper VAS produced very similiar stimulus‐response functions. The ratio scale properties of M‐VAS combined with its ease of administration and scoring in clinical settings offer the possibility of a simple yet powerful pain measurement technology in both research and health care settings.

Sensory-affective relationships among different types of clinical and experimental pain

&NA; Different types of pain patients used visual analogue scales (VAS) to rate their level of pain sensation intensity (VAS sensory) and degree of unpleasantness (VAS affective) associated with pain experienced at its maximum, usual, and minimum intensity. Women used the same VAS to rate their labor pain during early, active, and transition phases of stage I and in pushing (stage II). Consistent with the hypothesis that the affective dimension of clinical pain can be selectively augmented by perceived degree of threat to health or life, cancer pain patients and chronic pain patients gave higher VAS affective ratings as compared to VAS sensory ratings of their clinical pain, whereas labor patients and patients exposed to experimental pain gave lower VAS affective ratings compared to their VAS sensory ratings of pain. Affective VAS but not sensory VAS ratings of pain were considerably reduced when women in labor focused on the birth of the child as compared to when they focused on their pain. The results underscore the importance of utilizing separate measures of the sensory intensity versus the affective dimension of clinical pain and provide evidence that the affective dimension of different types of clinical pain is powerfully and differentially influenced by psychological contextual factors.

Psychosocial Impact of Urinary Incontinence in the Community‐Dwelling Population

oss of urinary control can have a sigmficant impact on the psychological and social well-being of the affected individual. Research has conL centrated on the prevalence, etiology, and management of urinary incontinence, but relatively little is known about the effects of this chronic condition on psychosocial functioning in daily life. This article reviews the literature related to psychosoaal impact of urinary incontinence in the communitydwelling adult population. The focus is on the individual with incontinence who is otherwise healthy, mentally intact, and residing independently in the community. Issues related to the definition and measurement of psychosocial impact are discussed. Relevant research findings are presented on the type and degree of psychosocial effects resulting from incontinence, differences in impact related to the underlying etiology of incontinence, and the relationship of psychosocial impact to severity measures of urinary incontinence. Recommendations for future research are also proposed.

Effects of extraversion and neuroticism on experimental pain, clinical pain, and illness behavior

&NA; The effects of 2 personality traits, extraversion and neuroticism, on experimental and clinical pain were characterized in a group of myofascial pain dysfunction (MPD) patients. Extraverts did not differ from introverts in visual analogue scale (VAS) sensory or VAS affective ratings of graded 5‐sec nociceptive temperature stimuli (43–51°C) nor in VAS sensory‐VAS affective relationships related to their clinical pain. However, high extravert patients scored lower on affective inhibition (Pilowsky Illness Behavior Questionnaire; IBQ) compared to low extravert patients. This result is consistent with previous suggestions that extraverts inhibit overt expressions of suffering less than do introverts. High neurotic patients did not differ from low neurotic patients in their VAS sensory ratings of either experimental or clinical pain. Their VAS affective ratings of both types of pain were marginally higher as compared to low neurotic patients. As hypothesized, high neurotic score patients gave higher VAS ratings of emotions related to suffering and scored higher on items related to affective disturbance on the IBQ as compared to low neurotic score patients. Overall, the results indicate that the personality traits of neither extraversion nor neuroticism affect sensory mechanisms of nociceptive processing but appear to exert their influence by means of cognitive processes related to the ways in which people constitute the meanings and implications of pain.

Brain evoked potentials are functional correlates of induced pain in man

&NA; Electrical potentials evoked by 5 intensities of painful dental stimulation were recorded at the scalp. During testing, volunteers indicated subjective painfulness by verbal pain ratings and visual analogue scales. Evoked potentials (EPs) to each intensity, observed between 50 and 400 msec, were characterized by 4 waveform components. The peak‐to‐peak amplitudes, but not the peak latencies, of all 4 EP components systematically increased with increased stimulation. The amplitudes of the two earlier components correlated with stimulus intensity when the effect of subjective painfulness was controlled, but this was not the case for the later components. In contrast, the amplitudes of the two later components were associated with subjective painfulness but not with stimulus intensity. A strong linear relationship was observed between subjective painfulness and peak‐to‐peak amplitude for the EP component observed between 175 and 260 msec. The data suggest that the earlier EP components may reflect sensory transmission processes while the later components indicate brain activity when pain is perceived.

Cognitive, Affective, and Behavioral Effects of Reminiscence Group Therapy on Demented Elderly:

Twenty-seven demented elderly nursing home residents were given either reminiscence group therapy or supportive group therapy or were assigned to a no-treatment control group. The self-reported level of depression in participants given reminiscence therapy was positively affected compared to participants in the supportive therapy and control groups, but no significant effects were found for cognitive or behavioral functioning. Results are discussed in terms of the issue of the applicability of reminiscence therapy for cognitively impaired persons, the appropriateness of the measures used in this study to assess depression, cognitive ability and behavioral functioning, and in conjunction with clinical observations made during the process of therapy.

Detection and decision factors in pain perception in young and elderly men

&NA; The effect of age on ability to discriminate between levels of electrical stimulation of tooth pulp and willingness to report shocks as painful was evaluated using the Sensory Decision Theory. While threshold did not increase with age for tooth pulp stimulation as is often observed for thermal pain thresholds, a significant age deficit in ability to discriminate between suprathreshold shocks was observed. Significant changes with age in willingness to report the electrical shocks as painful were also observed. These results indicate that changes with age in pain perception are complex, involving not only possible discrimination deficits but also changes in bias for and against labeling noxious events as painful. These findings stress the need for within individual comparisons of laboratory techniques for evoking acute pain experiences where variables such as age are under consideration.

Assessment of recovery from injury to inferior alveolar and mental nerves

Thirty-four patients had surgery near but not transecting either the inferior alveolar nerve or mental nerve. Thermal tests revealed that between 62% and 81% of the nerves that were evaluated had sensory deficits. Sixty-seven percent of patients had abnormal intraoral and extraoral responses to fine tactile testing. The least discriminative test was two-point contact. A smaller percentage (14% to 23%) were hyperpathic to heat stimuli, and a few (5% to 15%) had completely normal thermal and tactile sensation. A high percentage (43% to 71%) of patients elected to have corrective nerve surgery.

A simultaneous comparison of fentanyl's analgesic effects on experimental and clinical pain.

&NA; Intravenous administration of 0.8 &mgr;g/kg and 1.1 &mgr;g/kg fentanyl in low back pain patients reduced both sensory intensity and unpleasantness visual analogue scale (VAS) responses to experimental pain evoked by graded 5‐sec nociceptive temperature stimuli (45–51°C) as well as VAS‐sensory and VAS‐affective responses to clinical pain. Fentanyl produced similar decreases in VAS‐sensory responses to experimental and clinical pain. Fentanyl produced nearly equal reductions in VAS‐sensory and VAS‐affective responses to experimental pain but greater reductions in clinical pain VAS‐affective as compared to clinical pain VAS‐sensory responses. This interaction of type of pain (experimental versus clinical) and pain dimension (sensory versus affective) results from either a steeper sensory intensity‐unpleasantness relationship for clinical pain as compared to experimental pain or additional selective influences of opiates on affective factors uniquely related to clinical pain. These results indicate that low to moderate doses of opiates reduce both sensory and affective dimensions of pain and strongly suggest that changes in pain affect occur mainly as a direct consequence of reductions in pain sensation intensity.

Baroreflex control of plasma norepinephrine and heart period in healthy subjects and diabetic patients.

Resting diabetic patients may have excessively rapid heart rates, reduced heart rate variability, and subnormal plasma catecholamine levels. Although all of these abnormalities may relate in some way to baroreceptor reflex function, there have been surprisingly few attempts to evaluate systematically baroreflex mechanisms in diabetic patients. Accordingly, we studied autonomic responses over a range of pharmacologically induced arterial pressure changes in 10 unselected young adult insulin-dependent diabetic patients who had no symptoms of autonomic neuropathy, and 12 age-matched nondiabetic subjects. Sympathetic responses were estimated from antecubital vein plasma norepinephrine levels, and parasympathetic responses were estimated from electrocardiographic R-R intervals and their variability (standard deviation). Both were correlated with other noninvasive indexes of peripheral and central nervous system function. Multiple derangements of baroreflex function were found in the diabetic patients studied. Sympathetic abnormalities included subnormal baseline norepinephrine levels, virtual absence of changes of norepinephrine levels during changes of arterial pressure, and supranormal pressor responses to phenylephrine infusions. Parasympathetic abnormalities included subnormal baseline standard deviations of R-R intervals, and R-R interval prolongations during elevations of arterial pressure which were unmistakably present, but subnormal. Our data suggest that in diabetic patients, subnormal baseline plasma norepinephrine levels may signify profound, possibly structural defects of sympathetic pathways. Subnormal resting levels of respiratory sinus arrhythmia may have different implications, however, since vagal, unlike sympathetic reflex abnormalities, can be reversed partly by arterial pressure elevations.