Identification and Characterization of Unique Subgroups of Chronic Pain Individuals with Dispositional Personality Traits.

Objective. The current study attempted to identify and characterize distinct CP subgroups based on their level of dispositional personality traits. The secondary objective was to compare the difference among the subgroups in mood, coping, and disability. Methods. Individuals with chronic pain were assessed for demographic, psychosocial, and personality measures. A two-step cluster analysis was conducted in order to identify distinct subgroups of patients based on their level of personality traits. Differences in clinical outcomes were compared using the multivariate analysis of variance based on cluster membership. Results. In 229 participants, three clusters were formed. No significant difference was seen among the clusters on patient demographic factors including age, sex, relationship status, duration of pain, and pain intensity. Those with high levels of dispositional personality traits had greater levels of mood impairment compared to the other two groups (p < 0.05). Significant difference in disability was seen between the subgroups. Conclusions. The study identified a high risk group of CP individuals whose level of personality traits significantly correlated with impaired mood and coping. Use of pharmacological treatment alone may not be successful in improving clinical outcomes among these individuals. Instead, a more comprehensive treatment involving psychological treatments may be important in managing the personality traits that interfere with recovery.

The Long Term Role of Anxiety Sensitivity and Experiential Avoidance on Pain Intensity, Mood, and Disability among Individuals in a Specialist Pain Clinic.

Background. Anxiety sensitivity (AS) and experiential avoidance (EA) have been shown to have an interactive effect on the response an individual has to chronic pain (CP) potentially resulting in long term negative outcomes. Objective. The current study attempted to (1) identify distinct CP subgroups based on their level of EA and AS and (2) compare the subgroups in terms of mood and disability. Methods. Individuals with CP were recruited from an academic pain clinic. Individuals were assessed for demographic, psychosocial, and personality measures at baseline and 1-year follow-up. A cluster analysis was conducted to identify distinct subgroups of patients based on their level of EA and AS. Differences in clinical outcomes were compared using the Repeated Measures MANOVA. Results. From a total of 229 participants, five clusters were formed. Subgroups with lower levels of AS but similar high levels of EA did not differ in outcomes. Mood impairment was significantly greater among those with high levels of EA compared to lower levels (p < 0.05). Significant improvement in disability (p < 0.05) was only seen among those with lower levels of EA and AS. Conclusions. This cluster analysis demonstrated that EA had a greater influence on mood impairment, while both EA and AS levels affected disability outcomes among individuals with CP.

Mood, Disability, and Quality of Life among a Subgroup of Rheumatoid Arthritis Individuals with Experiential Avoidance and Anxiety Sensitivity.

Objective. The current study aimed to identify and characterize distinct RA subgroups based on their level of EA and AS and compares the difference among the subgroups in mood, disability, and quality of life. Methods. Individuals with chronic pain for at least 3 months were recruited from an academic rheumatoid clinic. Participants were assessed for demographic, psychosocial, and personality measures. A two-step cluster analysis was conducted to identify distinct subgroups of patients. Differences in clinical outcomes were compared using the Multivariate ANOVA based on cluster membership. Results. From a total of 223 participants, three distinct subgroups were formed based on cluster analysis. Cluster 1 (N = 78) included those with low levels of both EA and AS. Cluster 2 (N = 81) consisted of individuals with moderate levels of EA and low levels AS. Cluster 3 (N = 64) included those with moderate levels of EA and high AS. Compared to those in Cluster 1, those in Cluster 3 had significantly higher levels of mood impairment and disability and lower quality of life (p < 0.05). Significantly lower levels of mood impairment were seen in Cluster 1 compared to Cluster 2 (p < 0.05). However, no significant difference in disability or quality of life was seen between the two groups. Conclusions. The three subgroups differed significantly in levels of impairment in mood, disability, and quality of life. However, levels of EA had a greater impact on disability and quality of life than AS.

Cerebral blood flow in hypertensive patients: an initial report of reduced and compensatory blood flow responses during performance of two cognitive tasks.

We asked whether the altered cerebral vasculature associated with essential hypertension might dampen or redirect the regional cerebral blood flow (rCBF) response to cognitive work. Relative rCBF was assessed with [(15)O]water positron emission tomography during a working memory task, a memory span task, and two perceptual control tasks. Unmedicated hypertensive patients and control subjects differed in rCBF response during both memory tasks. Hypertensives showed relatively diminished rCBF responses in right hemisphere areas combined with compensatory activation of homologous areas in the left cerebral cortex. Essential hypertension appears to selectively influence the circulatory reserve of portions of cerebral cortex and secondarily induce recruitment of other cortical areas to process certain tasks.

Process-Parameter-Dependent Optical and Structural Properties of ZrO(2) MgO Mixed-Composite Films Evaporated from the Solid Solution.

The process-parameter-dependent optical and structural properties of ZrO(2)MgO mixed-composite material have been investigated. Optical properties were derived from spectrophotometric measurements. By use of atomic force microscopy, x-ray diffraction analysis, and energy-dispersive x-ray (EDX) analysis, the surface morphology, grain size distributions, crystallographic phases, and process-dependent material composition of films have been investigated. EDX analysis made evident the correlation between the oxygen enrichment in the films prepared at a high level of oxygen pressure and the very low refractive index. Since oxygen pressure can be dynamically varied during a deposition process, coatings constructed of suitable mixed-composite thin films can benefit from continuous modulation of the index of refraction. A step modulation approach is used to develop various multilayer-equivalent thin-film devices.

MgO-Al(2)O(3)-ZrO(2) Amorphous Ternary Composite: A Dense and Stable Optical Coating.

The process-parameter-dependent optical and structural properties of MgO-Al(2)O(3)-ZrO(2) ternary mixed-composite material were investigated. Optical properties were derived from spectrophotometric measurements. The surface morphology, grain size distributions, crystallographic phases, and process-dependent material composition of films were investigated through the use of atomic force microscopy, x-ray diffraction analysis, and energy-dispersive x-ray analysis. Energy-dispersive x-ray analysis made evident the correlation between the optical constants and the process-dependent compositions in the films. It is possible to achieve environmentally stable amorphous films with high packing density under certain optimized process conditions.

Diagnosis of conversion disorders in a rehabilitation setting.

Conversion disorders are unexplained symptoms or deficits that mimic neurological problems and affect voluntary motor and sensory functions. Historically, conversion symptoms were thought to reflect underlying psychological conflicts although recent behavioural theories view them as learned responses to stressful life circumstances and emphasize environmental contingencies in the maintenance of the disorder. Although early studies often revealed underlying organic disease in patients initially diagnosed with Conversion Disorder, this now occurs less frequently because of increased sophistication of diagnostic tools and better understanding of neurological disorders. However, misdiagnosis is still common because of reliance on 'negative' diagnostic testing and unvalidated 'positive signs' misinterpreted as indicative of hysteria. Psychological factors may affect the course of almost every major category of disease and in many cases a diagnosis of hysteria is not indicated and the more appropriate diagnosis is Psychological Factors Affecting A Medical Condition. It is not possible to definitively differentiate between conscious and unconscious production of symptoms thus blurring the distinction between Conversion and Factitious disorders.

Strategic-behavioural intervention in the inpatient rehabilitation of non-organic (factitious/conversion) motor disorders.

Conversion or factitious disorders manifesting as chronic motor disorders are difficult and complex management problems. A number of published case studies and series have illustrated that these patients may respond to a rehabilitation program emphasizing physical therapies and behaviour therapy. However, this standard behavioral approach was not successful with the majority of our patients. In contrast, an alternative strategic-behavioral rehabilitation approach developed for intractable cases proved highly effective. Among 17 patients who underwent the strategic behavioural approach, 13 showed complete or near complete resolution of symptomatology. Nine of these successfully treated patients had previously failed to improve using a standard behavioral rehabilitation program.

Misdiagnosis of chronic pain as hysterical.

Chronic soft tissue pain disorders are not well understood from a pathophysiological standpoint. Psychological difficulties are common, clinical signs incompatible with conventional understanding of the nervous system are often present and these disorders usually fail to respond to medical interventions. When this constellation of factors is combined with unresolved litigation/compensation issues, it is not surprising that chronic pain disorders are often misdiagnosed as hysterical or psychological in origin. Unfortunately, this psychiatric diagnosis itself may have significant negative consequences which too often are not appreciated and can significantly increase the likelihood of treatment failure.

Hypertension and neuropsychological performance in men: interactive effects of age.

Potentially interactive effects of hypertension and age on the performance of neuropsychological and information processing tests were examined in 123 untreated hypertensive and 50 normotensive men. After covarying education, average alcohol consumption, trait anxiety, and depression scores, results indicated an interaction of age and hypertension. Young hypertensive men (23-40 years) scored significantly worse than young normotensive men on tests of attention/executive function and working memory; middle-aged hypertensive (41-56 years) and normotensive participants were not distinguished by any measures. Hypertensive men performed significantly more poorly than normotensive men on tests of manual dexterity. Results suggest that neuropsychological sequelae of hypertension are more pronounced in young than in middle-aged hypertensive individuals and are independent of various demographic, psychosocial, and alcohol-related factors.

Systolic hypertension in critical aortic stenosis and the effect of valve replacement.

All cases of aortic valve replacement (AVR) for critical aortic stenosis (AS) in a 3 year period were reviewed and 43 cases were included in the study. Twenty patients had systolic hypertension preoperatively by sphygmomanometry and/or by measurement of central aortic pressure during cardiac catheterization. These patients also had a significantly higher mean left ventricular (LV) peak pressure than their normotensive counterparts. Following AVR all 43 patients were normotensive. This study suggests that not only can an elevated blood pressure (BP) be found in the presence of AS, but that AS itself can cause hypertension, in which case AVR can result in normalization of BP. We suggest that the systolic hypertension is due to a partial transmission of the higher LV peak pressure across the aortic valve, despite the stenotic valve acting as a pressure barrier. This effect may be more pronounced the tighter the stenosis.

The effect of litigation status on adjustment to whiplash injury.

STUDY DESIGN: This retrospective study examined the effect of civil litigation on reports of pain and disability in chronic pain patients who sustained whiplash injuries after a motor vehicle accident. OBJECTIVES: To examine the effect of litigation on adjustment to chronic pain. SUMMARY OF BACKGROUND DATA: A common methodologic weakness with many studies in this area is the composition of the nonlitigant group, which often includes individuals who have completed litigation as well as those who opted not to litigate. This introduces a confound in that litigant and nonlitigant groups differ not only with respect to litigation status but with respect to any factors that predispose one to litigate. METHODS: Questionnaire data were obtained from 41 patients (current litigants) in the process of litigation and 21 patients (postlitigants) who had completed litigation. Subjects completed self-report measures assessing demographic characteristics, psychological distress, sleep disturbance, employment status, and various pain indices. RESULTS: There were no significant group differences in demographic characteristics, employment status, or psychological distress. Litigants, however, reported more pain than did postlitigants. Group differences in pain reports remained statistically significant even after controlling for length of time since accident and initial severity of the injuries. CONCLUSIONS: That litigation status did not predict employment status suggests that secondary gain does not figure prominently in influencing the functionality of these patients. The rather robust effect of litigation status on pain reports is discussed with respect to the potential mediational role of the stress of litigation.

Clinical use of ambulatory blood pressure monitoring. A review of value in patient care.

OBJECTIVE: To examine the value of ambulatory blood pressure monitoring in routine clinical use. DESIGN: We retrospectively reviewed 350 determinations made over a 4-year period. SETTING AND PATIENTS: A practice-based sample of patients attending the Hypertension Outpatient Clinic. RESULTS: Successful records were obtained in 346 of these procedures and night/sleep recordings were accomplished in 320. Monitor readings compared satisfactorily with auscultatory determinations. Declines in systolic and diastolic blood pressure during night/sleep of 8.2% and 13.2%, respectively, and a fall in the heart rate of 12.0% were noted; these declines were significantly lesser in patients with diabetes. Age, gender, therapy, and 24-hour average blood pressures, however, had minimal relationship to the night/sleep declines in blood pressure and heart rate. CONCLUSIONS: Twenty-four-hour blood pressure monitoring is acceptable to patients. Night/sleep declines in blood pressure are blunted in diabetics.

Reversible nephrotic syndrome due to high renin state in renovascular hypertension.

Unilateral renal artery stenosis can lead to a non-functional kidney which secretes large amounts of renin. Four cases are presented in which the high renin state resulted in hypertension, proteinuria from the intact contralateral kidney, and secondary aldosteronism. The proteinuria was in the nephrotic range, which is unusual in renovascular hypertension, but gradually disappeared after correction of the high renin state by removal of the renin-secreting kidney or administration of an ACE inhibitor. Accordingly, when there is marked proteinuria in the presence of new-onset or rapidly progressive hypertension, hypokalaemic alkalosis, and a high peripheral PRA, renal artery stenosis should be considered since the proteinuria may be reversible after nephrectomy, repair of the ischaemic kidney or medical therapy.

The effect of prophylactic nifedipine on renal function in patients administered contrast media.

STUDY OBJECTIVE: To determine if prophylaxis with nifedipine could decrease the frequency of contrast medium-induced renal impairment. DESIGN: Prospective, randomized clinical trial. SETTING: A university-affiliated hospital. PATIENTS: Patients undergoing scheduled radiologic examinations involving infusion of contrast media. INTERVENTIONS: Forty-two patients were randomized to receive nifedipine 10 mg orally 1 hour before the imaging procedure, and 43 to receive no treatment. MEASUREMENTS AND MAIN RESULTS: Baseline serum creatinine levels were compared with maximum levels 24 and 48 hours after administration of contrast medium. No statistically significant difference was seen in either the mean change or mean percentage change in serum creatinine between the control and nifedipine groups. The mean changes in serum creatinine were +7.4 mumol/L in the control group and +2.7 mumol/L in the nifedipine group (p = 0.33); the mean percentage changes were +10.2% and +4.8%, respectively (p = 0.54). CONCLUSION: Regardless of statistical analysis, it is unlikely that elevations in serum creatinine of this magnitude (< 0.1 mg/dl) are of clinical significance. We therefore conclude that prophylactic nifedipine is not clinically beneficial in preserving renal function in patients receiving contrast medium and that the agent should not be routinely administered for this purpose.

Strategic-behavioral intervention in the treatment of chronic nonorganic motor disorders.

Chronic nonorganic motor disorders pose particular difficulties because of a combination of diagnostic confusion and intractability to psychotherapeutic or behavioral interventions. Three cases are presented, all of whom failed a rehabilitation approach that emphasized basic behavioral principles of shaping and reinforcement. Despite this initial failure, all three patients showed dramatic and rapid improvement after implementation of an intervention combing elements of strategic and behavior therapy. The strategic element consisted of placing patients in a double bind by telling them full recovery constituted proof of an organic etiology and failure to recovery constituted conclusive evidence of a nonorganic or psychiatric etiology. These cases also illustrate the difficulty in distinguishing between conversion and factitious disorders.