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.

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

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.

Suppression of first pain and slow temporal summation of second pain in relation to age.

BACKGROUND: Thermal stimuli delivered to skin of the arms or legs can produce a sensation of two distinct pains. These pains have been associated with activity in A-delta (first pain) and C-fiber (second pain) nociceptive fibers, respectively. Under appropriate conditions first pain decreases in intensity (adaptation) while second pain increases in intensity (slow temporal summation). Change in first and second pain to repeated stimulation of skin has not been assessed in relation to age. METHODS: Ten younger (M = 25 years) and ten older (M = 65 years) subjects participated in a study of first and second pain intensity elicited by nociceptive range heat pulses (.7 second pulses; adapting temperature 39 degrees C to a stimulus temperature of 51 degrees C) delivered to skin of arms and legs. Response times to sensations of first and second pain were assessed to provide evidence that subjects were responding to first and second pain. RESULTS: Age groups did not differ on pain intensity ratings of initial stimuli to previously unstimulated skin for either first or second pain. Older subjects failed to evidence slow temporal summation of second pain at the leg. Response times to first, but not second pain from the leg were delayed in the elderly. Response times to first and second pain at the arm did not differ with age. Auditory response times were slower in the older group. CONCLUSIONS: Age did not influence pain intensity to unadapted and unsensitized skin. Slow temporal summation of second pain was not observed at the leg in the older group, suggesting that mechanisms subserving C-fiber mediated sensitization of second order nociceptive neurons may fail with age. Longer response times to first, but not second pain in older subjects may represent an age effect on myelinated (A-delta; first pain) and not unmyelinated (C-fiber; second pain) nociceptive afferents and may represent a type of small fiber peripheral neuropathy.

Fluid loss quantitation test in women with urinary incontinence: a test-retest analysis.

A modified perineal pad-weighing method for objective quantitation of fluid loss is presented. The bladder was filled by retrograde flow, a sequence of provocative maneuvers was performed under direct supervision, and fluid loss was determined by pad weights. An analysis of immediate test-retest correlation and variability was done in patients with either sphincteric incompetence alone (N = 46) or detrusor instability with or without concomitant sphincteric incompetence (N = 21). Test-retest correlations were high in both groups, suggesting that the method could be applied as an index of severity of urinary incontinence in women. Test-retest within-patient variability was considerable, and limits its usefulness in the analysis of treatment outcome.

Psychosocial impact of urinary incontinence in women.

This study explored the psychosocial impact of urinary incontinence and investigated its relationship to urodynamic diagnosis and degree of involuntary urine loss. The sample comprised 69 community-dwelling women, ages 55 years and older, who were ambulatory and mentally intact, and who had volunteered in a clinical trial on incontinence. Psychosocial impact was measured by an investigator-designed instrument, the Incontinence Impact Questionnaire. Urodynamic evaluation included detrusor and urethral sphincteric function tests. Subjects were grouped into two urodynamic diagnostic categories: sphincteric incompetence (N = 47) and detrusor instability with or without concomitant sphincteric incompetence (N = 22). Severity of incontinence was determined by a one-week urinary diary and a fluid loss quantitation test. Each of the items on the Incontinence Impact Questionnaire was affected by urinary incontinence, although to varying degrees. Activities involving unfamiliar places where the availability of restrooms was unknown were most affected. Subjects with detrusor instability with or without concomitant sphincteric incompetence reported significantly higher impact than subjects with sphincteric incompetence alone. There were modest correlations between psychosocial impact scores and both the number of weekly incontinent episodes and the quantitation of fluid loss. The results in this study population indicate that the relationships between the perceived impact of incontinence and objective measures of its severity are complex and not directly proportionate.

The urinary diary in evaluation of incontinent women: a test-retest analysis.

This study investigated the use of a one-week urinary diary in the evaluation of incontinent women. The sample consisted of 50 community-dwelling women, ages 55 years and older, ambulatory, and mentally intact, who were volunteers in a clinical trial on behavioral management for urinary incontinence. All subjects kept a urinary diary for two consecutive weeks. An analysis of the immediate (one-week) test-retest variability and correlations on weekly diurnal micturition frequency, nocturnal micturition frequency, and urinary incontinent episodes were performed in subjects with sphincteric incompetence alone (N = 34) and in those with detrusor instability with or without concomitant sphincteric incompetence (N = 16). In addition, information obtained on history was compared with that obtained from the diary. Diurnal micturition frequency, nocturnal micturition frequency, and number of incontinent episodes were highly reproducible and did not differ by urodynamic diagnosis. Test-retest correlations were highest with diurnal micturition frequency and incontinent episodes. Lower correlations were observed with nocturnal micturition frequency, with a significant difference observed between diagnostic groups. Although modest, significant relationships between data collected by history and diary were observed in the overall sample, but there were significant differences between diagnostic groups. The results indicate that a one-week diary is a reliable method for assessing the frequency of voluntary micturitions and involuntary episodes of urine loss.

Effects of nitrous oxide inhalation on brain potentials evoked by auditory and noxious dental stimulation.

1. Effects of inhaling nitrous oxide in oxygen were observed in subjects undergoing noxious dental (N=10) or nonnoxious auditory (N=10) stimulation. Evoked potentials (EPs), 100-500 msec poststimulus, were recorded at vertex, and peak-to-peak amplitudes as well as peak latencies were quantified. 2. Both dental and auditory EPs were reduced by 33% nitrous oxide in oxygen concentration and a dose-related effect was seen in the auditory modality when the concentration was increased to 50%. 3. These observations demonstrate that nitrous oxide inhalation has a broad impact on neurophysiological function in addition to behaviorally determined analgesia.

Symptom report in orofacial pain patients: relation to chronic pain, experimental pain, illness behavior, and personality.

A study was conducted to determine symptom report patterns in a heterogenous population of orofacial pain patients and to evaluate how symptom patterns relate to various dimensions of the human pain experience. Results indicated that symptoms frequently associated with chronic orofacial pain disorders can be described by four indices related to the temporomandibular joint (TMJ) and its movement; discomfort of and parafunctional activities related to the masticatory muscles; interference of pain with activities of daily living; and presence of orofacial pain unrelated to myogeneous or arthrogenous TMJ disorders. Of these four symptom indices, only the pain interference (symptom) index was related to clinical pain and illness behavior. None was related to personality. Two of the indices were influenced by diagnosis. Biomechanical symptoms and parafunctional activities appear to be insignificantly related to perceived pain intensity, pain responsiveness, illness behavior, or personality, but are related to diagnosis. The results indicated that relatively simple symptom checklists have potential utility in screening orofacial pain patients and in evaluation of treatment outcome.

Age and forgetting rate with pictorial stimuli.

The rate of forgetting standardized line drawings of common objects was assessed in groups of young (M age = 22 years) and older (M age = 70.5 years) subjects. The two groups forgot equal quantities of pictorial stimuli over successive intervals of 10 min, 2 hr, and 48 hr, after being matched for original learning. In contrast, the older subjects showed the expected age decrement in reproduction of geometric designs from memory. These findings indicate that aging does not affect retention of pictures when differences in learning and retrieval abilities are controlled.

Pain-related limitation in activities of daily living in patients with chronic orofacial pain: psychometric properties of a disability index.

Pain-related limitations in activities of daily living are presented for 272 patients reporting orofacial pain of the temporomandibular region using the seven-item Pain Disability Index. Results showed that the factor structure for orofacial pain patients differed little from the factor structure for outpatients visiting chronic pain clinic settings. Analysis of pain diagnostic subgroups showed that patients suffering myogenous complaints had higher scores for four of seven daily-living activities that involved pain-related limitations than patients suffering discal disorders. The factor analytical findings indicated that these patients share common pain-related limitations in activities of daily living. These findings are also consistent with previous results indicating greater pain in orofacial pain patients diagnosed with pain complaints primarily myogenous in origin than in pain patients having discal disorders.

Geriatric pain. Pain perceptions in the old.

Pain is likely to be a different problem in the old-old and the frail elderly compared to the young-old. Little attention has been paid to date to the impact of pain on quality of life in dementia patients, in postfracture patients, or in nondemented nursing home residents. It is likely that pain is a major source of depression and suffering in these individuals. Although currently available pain assessment tools are appropriate for the young-old, their usefulness in the old-old has not yet been evaluated. Additional pain assessment tools are needed for uncommunicative patients. The effectiveness of pain relief treatments in such patients cannot be evaluated without appropriate assessment. Such assessment may depend upon well-developed behavioral and observational techniques, particularly in individuals with later-life dementias such as dementia of the Alzheimer's type-a condition responsible for in excess of 60% of nursing home residents.

A clinical laboratory model for direct assessment of medication-induced antihyperalgesia and subjective effects: initial validation study.

Analgesic medications are often tested in clinical laboratory studies by observing their ability to reduce the pain produced by noxious stimuli presented to healthy skin. These medications may then be used clinically to reduce disease-related hyperalgesia. This article describes a clinical laboratory model useful for testing a medication's ability to reduce hyperalgesia in humans. Results demonstrate that ultraviolet (UV) light induces hyperalgesia, commonly prescribed analgesic medications reduce UV-induced hyperalgesia, and this UV-induced hyperalgesia model can be used to assess the time course of a medication's antihyperalgesia effects. Coupled with participant-rated measures of drug liking and mood, this model may prove useful for predicting the clinical efficacy and side-effect profile of novel analgesic medications in cost-efficient and statistically powerful laboratory studies.

Otalgia and aversive symptoms in temporomandibular disorders.

The term Costen's syndrome has been used in the dentomedical literature to describe a constellation of craniofacial symptoms. Since some of the same complaints have been reported in patients with "generalized" psychological distress, symptoms associated with the syndrome may not be useful in differential diagnosis of temporomandibular disorders. The present study investigated whether some somatic complaints, particularly tinnitus and dizziness, were pathognomonic in patients with chronic temporomandibular pain. Illness behavior and personality factors were studied for possible interrelationships with these symptoms. Factor analysis revealed that tinnitus and dizziness loaded on separate factors. Tinnitus loaded with nasal stuffiness, tearing, and itching of the eyelids and nose, while dizziness loaded with complaints of altered taste and smell and blurred vision. Neither was consistently related to measures of pain or to indices of illness behavior or somatic focus.

Current concepts of geriatric pain and its treatment.

Because stress and depression are prevalent in the elderly, the opportunity for pain to intensify stress and depression may be greater in older people than in the general population. Evidence that pain-related psychosomatic complaints are more frequent in the elderly further complicates the issue. Antidepressants that affect serotonergic systems may have analgesic properties independent of their antidepressant properties; eg, amitriptyline and doxepin. These drugs may have a more rapid effect on pain than on depression.

Effects of presenile dementia of the Alzheimer's type on brainstem transmission time.

Central transmission time (CTT) between the first and fifth wave of the brainstem auditory evoked potential (BAEP) was assessed in a group of patients clinically diagnosed as suffering from presenile dementia of the Alzheimer's type. CTT was significantly longer in patients compared to healthy young and elderly volunteers. Age per se did not result in prolonged peak latencies or CTT. These results indicate that far-field and early near-field evoked potentials may be of utility in early diagnosis of central nervous system dysfunction associated with diffuse degenerative diseases such as Alzheimer's and related diseases.