Lawrence S. Schoenfeld

A Controlled Trial of Transcutaneous Electrical Nerve Stimulation (TENS) and Exercise for Chronic Low Back Pain

A number of treatments are widely prescribed for chronic back pain, but few have been rigorously evaluated. We examined the effectiveness of transcutaneous electrical nerve stimulation (TENS), a program of stretching exercises, or a combination of both for low back pain. Patients with chronic low back pain (median duration, 4.1 years) were randomly assigned to receive daily treatment with TENS (n = 36), sham TENS (n = 36), TENS plus a program of exercises (n = 37), or sham TENS plus exercises (n = 36). After one month no clinically or statistically significant treatment effect of TENS was found on any of 11 indicators of outcome measuring pain, function, and back flexion; there was no interactive effect of TENS with exercise. Overall improvement in pain indicators was 47 percent with TENS and 42 percent with sham TENS (P not significant). The 95 percent confidence intervals for group differences excluded a major clinical benefit of TENS for most outcomes. By contrast, after one month patients in the exercise groups had significant improvement in self-rated pain scores, reduction in the frequency of pain, and greater levels of activity as compared with patients in the groups that did not exercise. The mean reported improvement in pain scores was 52 percent in the exercise groups and 37 percent in the nonexercise groups (P = 0.02). Two months after the active intervention, however, most patients had discontinued the exercises, and the initial improvements were gone. We conclude that for patients with chronic low back pain, treatment with TENS is no more effective than treatment with a placebo, and TENS adds no apparent benefit to that of exercise alone.

Normative model for cold pressor test

The cold pressor test elicits an emotional/motivational pain experience from the immersion of a limb in cold water. It has been widely used to evaluate (experimental and chronic) pain. However, normative models for quantification and comparison for pain tolerance have not previously been established. This study developed a normative mathematical model for pain tolerance using the cold pressor test with over 600 subjects. Norms for age, sex, and ethnic group were calculated. In addition, chronic pain patients were compared with painfree patients to determine normative differences in response. The results indicate that at any given age Anglo-Saxon males have the longest tolerance time followed by non-Anglo-Saxon males, Anglo-Saxon females, and finally non- Anglo-Saxon females. There is a consistent decrease in tolerance time as the male age increases and minimal change in tolerance time as the female age increases. Chronic pain patients exhibited the same type of pain response pattern as healthy volunteers when corrected for age, sex, and ethnocultural subgroup.

Can trials of physical treatments be blinded? The example of transcutaneous electrical nerve stimulation for chronic pain

Therapeutic trials often attempt to “blind” patient and investigator to the true nature of treatments received, reducing the influences of conscious or subconscious prejudices. In drug trials, this is accomplished with placebo tablets, but blinding in trials of physical treatments is more problematic. This issue arose in a clinical trial of transcutaneous electrical nerve stimulation (TENS) for patients with chronic low back pain. Several study design features were incorporated to promote blinding: use of sham TENS units visually identical with real units, exclusion of potential subjects with previous TENS experience, avoidance of a crossover design and use of identical visit frequency, instructions and modifications in electrode placement. Subjects were asked not to discuss treatments with the clinicians who performed outcome assessments. Both patients and clinicians were asked to guess actual treatment assignments at the trials end. Every patient in the true TENS group believed the unit was functioning properly, but the degree of certainty varied. In the sham TENS group, 84% also believed they had functioning units, but their certainty was significantly less than in the active treatment group. Differences in patient perceptions did not affect compliance, as the two groups had similar dropout rates, appointment compliance, days of TENS use and daily duration of TENS use. Clinicians guessed treatments correctly 61% of the time (as opposed to 50% expected by chance), again suggesting partial success in blinding. These efforts at blinding may partly explain the negative trial results for TENS efficacy. We conclude that complete blinding is difficult to achieve because of sensory difference in treatment and unintended communication between patient and examiner. Nonetheless, trials of physical treatments can achieve partial blinding with the techniques described here, and the success of blinding can be assessed with simple questions at study completion.

Intravenous regional sympatholysis: A double-blind comparison of guanethidine, reserpine, and normal saline

This double-blind, randomized study was designed to compare the effectiveness of intravenous regional sympatholysis using guanethidine, reserpine and normal saline. Twenty-one patients with reflex sympathetic dystrophy of an upper or lower extremity were enrolled and received intravenous regional blockade (IVRB) with one of the three medications. There was significant pain relief in all three groups at 30 min. There were no significant differences among the three groups in the degree of pain relief, the number of patients obtaining pain relief in the 30 min after the block, or the number of patients reporting more than 50% pain relief for more than 24 hr. The saline groups high rate of pain relief could be partially due to a mechanism of tourniquet-induced analgesia.

Anger and hostility in tension-type headache.

SYNOPSIS

P-A-I-N: a four-cluster MMPI typology for chronic pain.

&NA; A 4‐cluster empirically derived MMPI typology for chronic pain sufferers has been demonstrated by combining the results of 10 investigative teams. These MMPI ‘types’ have been labeled P‐A‐I‐N and appear to have important clinical and demographic correlates. Type P is the most ‘psychopathological’ looking as nearly all scales are usually elevated. Type P patients are extreme in their claims of physical illness, psychological distress and social maladaptation. Demographic correlates include poor education, high rates of unemployment, and limited household income. Type A is defined by a ‘conversion V’ on the ‘neurotic’ triad scales. It has no unique correlates. Type I has elevations on all of the neurotic triad scales and on no others. Type I patients appear to be the most physically infirm with multiple surgeries and hospitalizations. They may not improve physical status with treatment, but appear to benefit psychologically. Type N profiles are ‘normal’ in that no scale, except perhaps scale K, is often elevated. Type N patients are moderate in their claims of ill health, often are better educated and employed, and appear to respond well to treatment. Classification rules have been proposed to allow patient‐typing without a computer. Use of these rules should allow programmatic research into treatment/ type interactions even in the ordinary clinical setting. The typology appears well enough established to allow for prospective studies to test theoretical hypotheses drawn from the literature base.

Knowledge competence in clinical and counseling training and readiness for internship

The concept of competence has become the driving force in the education and training of professional psychologists. In fact, competence has evolved into increasingly sophisticated forms, now perhaps best represented by the cube model, which integrates foundational, functional, and developmental variables into ideas about professional training. This article considers one component of professional training, scientific knowledge, and argues that knowledge competence, measured by the Examination for Professional Practice in Psychology, should occur before a student is certified as internship ready.

Studies of the Modified Somatic Perceptions Questionnaire (MSPQ) in patients with back pain. Psychometric and predictive properties

The Modified Somatic Perceptions Questionnaire (MSPQ) was designed to measure heightened somatic awareness among patients with chronic pain. It was hoped that this questionnaire would help predict therapeutic responses for back pain patients. The reliability, validity, and predictive characteristics of this scale were tested among 97 patients with chronic low-back pain enrolled in a clinical trial of transcutaneous nerve stimulation and stretching exercises. Internal consistency was good (alpha = 0.78), and correlations with the Zung depression scale and certain MMPI scales were significant. Correlations with a baseline functional scale (the Sickness Impact Profile) were stronger than those with the MMPI. Unfortunately, the MSPQ did not correlate with functional outcomes, and was only weakly associated with pain outcomes. Thus, the MSPQ appears to be reliable and valid, but the somatic perceptions it measures may have little relation to patient outcomes.

The current status of psychological assessment training in graduate and professional schools

Test-based psychological assessment is threatened by the policies of managed care organizations; however, research has demonstrated that test-based psychological assessment is quite valuable and economically justified when conducted by well-trained psychologists. This surfaces the question of the current status of graduate training in test-based psychological assessment. Results of this study indicate that clinical and counseling students currently receive almost equivalent training in test-based assessment. However, in a larger context, results indicate a lack of sound preparation in test-based assessment training for a large proportion of clinical and counseling students. These findings are discussed in terms of their implications for the field and, more specifically, for graduate and internship training.

Preinternship preparation in psychological testing and psychotherapy: What internship directors say they expect.

What levels of preinternship training in testing and psychotherapy do internship directors expect students to have as they enter internship? This study addressed the question by surveying internship directors of all members of the Association of Postdoctoral and Internship Centers and asking them to specify the numbers of testing and psychotherapy experiences they believe an intern candidate should have prior to entering the internship. The results demonstrate similarities and differences in director expectations and have implications for preinternship students, graduate programs, and internships themselves.