Knut Dalen

EMG feedback in the treatment of myofascial pain dysfunction syndrome

The effect of electromyographic (EMG) biofeedback on frontalis and masseter muscle activity was compared with control conditions in two groups of patients with a diagnosis of myofascial pain dysfunction (MPD) syndrome. Patients were selected on the basis of clinical symptoms, radiographic evaluation, and a clinical examination. Depressed patients and patients with signs of a pathological condition in the temporomandibular joint were excluded. Both the experimental (EXP) and the control (CON) group went through two base-line screening sessions before treatment of the EXP group was started. Treatment consisted of eight biofeedback sessions, given twice a week for 4 weeks. Feedback was presented visually on a monitor. Treatment did not include any relaxation training. Control evaluations of both groups took place 1 week, 3 months, and 6 months after the end of treatment. The EXP group was able to reduce EMG levels in frontalis and masseter muscles significantly during training sessions. Follow-up data showed significantly reduced frontalis EMG levels in the EXP group after 3 and 6 months but not in the CON group. Both groups improved subjectively, as judged by reports on pain intensity and duration, but this improvement was significantly more pronounced in the EXP group. Objective clinical indices recorded throughout the study were uncorrelated with EMG changes or subjective reports. It is concluded that biofeedback training facilitated muscular relaxation and self-regulation in the EXP group and that visual EMG feedback, consisting of a patterning of frontalis and masseter muscle activity, can be recommended as an integrated part of MPD syndrome treatment.

Prediction of driving ability after inconclusive neuropsychological investigation.

Objective: The aim of the present study was to investigate the predictive value of neuropsychological tests for on-road evaluation outcome after inconclusive assessment. Methods and procedures: Thirty-five patients were assessed neurologically, neuropsychologically by traditional clinical tests and by on-road evaluation. Simple univariate tests, logistic regression and ROC-curve analysis were used to investigate the predictive power of different neuropsychological tests. Main outcomes and results: Six measures from the California Computerized Assessment Package (CalCAP) and the Digit-Symbol test from Wechsler Adult Intelligence Scale predicted the outcome of the on-road evaluation. A logistic regression analysis showed that a model with two variables from CalCAP and the Digit Symbol test predicted the results of the on-road driving evaluation with an overall accuracy of 84.8%. Conclusions: The findings indicate that the outcome of on-road assessment is most related to cognitive skills such as attention and processing speed in combination with cognitive flexibility.

Changes in health complaints after removal of amalgam fillings

The aim of the present study was to investigate whether removal of all amalgam fillings was associated with long-term changes in health complaints in a group of patients who attributed subjective health complaints to amalgam fillings. Patients previously examined at the Norwegian Dental Biomaterials Adverse Reaction Unit were included in the study and assigned to a treatment group (n = 20) and a reference group (n = 20). Participants in the treatment group had all amalgam fillings replaced with other restorative materials. Follow-ups took place 3 months, 1 and 3 years after removal of all amalgam fillings. There was no intervention in the reference group. Subjective health complaints were measured by numeric rating scales in both groups. Analysis of covariance was used to compare changes in health complaints over time in the two groups. In the treatment group, there were significant reductions in intra-oral and general health complaints from inclusion into study to the 3-year follow-up. In the reference group, changes in the same period were not significant. Comparisons between the groups showed that reductions in intra-oral and general health complaints in the treatment group were significantly different from the changes in the reference group. The mechanisms behind this remain to be identified. Reduced exposure to dental amalgam, patient-centred treatment and follow-ups, and elimination of worry are factors that may have influenced the results.

Dichotic listening, forced attention, and brain asymmetry in righthanded and lefthanded children

Righthanded and lefthanded 7-year-old children (both boys and girls) were compared for dichotic listening performance under free report and forced attention conditions. Previous findings from our laboratory have shown that, while adults reverse the right ear advantage (REA) during the forced-left condition, children do not. Since the finding in children was unexpected, the first aim of the present study was to replicate our previous results. A second aim was to include lefthanded children with the hypothesis that they should more easily revert to a LEA, because of less homogeneous lateralization. The results essentially replicated our previous findings, during all three recall conditions. No sex differences were observed, and both handedness groups showed the same overall response pattern.

Memory functions in persons with dental amalgam

Memory and psychophysiological variables in persons with self-reported reactions to dental amalgam (amalgam patients: N=26) and in persons without such symptoms (controls: N=21) were compared. The groups were matched regarding age, education, and amount of amalgam. Wechsler Memory Scale-Revised was obtained for all subjects and compared to amalgam points in a dose-response design. The results demonstrated that amalgam patients function on the same level as the controls regarding memory variables, attention, concentration, and delayed recall. Psychophysiological measures of skin conductance as correlates of attention and basal memory functions, were compared in the two groups. No differences between the two groups were observed and no correlation between memory variables and exposure to amalgam could be detected.

Inhibitory versus facilitory interference for Finger-Tapping to verbal and nonverbal, motor, and sensory tasks

The purpose of the present experiment was to investigate lateralized effects of concurrent verbal and nonverbal tasks on right- and left-hand finger-tapping. In addition to the verbal vs. nonverbal dichotomy, both motor and sensory tasks were used. It was predicted that a verbal motor task (reading aloud) would lead to more inhibitory interference for right-hand tappings than would a sensory verbal task (watching and remembering slides with nonsense syllables). Similarly, it was predicted that a motor nonverbal task (humming a tune) would lead to more left-hand inhibitory interference than would a sensory nonverbal task (watching pairs of spatial patterns). Results showed a predicted lateralized right-hand decrement in finger-tapping during the motor verbal task. However, an increase in left-hand tapping frequency above baseline was observed during both sensory tasks, while no significant difference was observed between the hands for the motor nonverbal task.

Personality variables in patients with self-reported reactions to dental amalgam.

Personality variables in persons with self‐reported reactions to dental amalgam (amalgam patients, n=26, 17 F, 9 M) and in others without such symptoms (controls, n=21, 14 F, 7 M) are compared. The groups were comparable regarding age, education, and amount of amalgam. Minnesota Multiphasic Personality Inventory‐2 (MMPI‐2) profiles were obtained for all subjects. On MMPI‐2, the amalgam patients presented a ‘conversion V’ pattern, and elevated psychasthenia and schizophrenia scales, reflecting an increased prevalence of psychological and somatic complaints compared with the controls. This indicates that amalgam patients experience ill health, as their personality profiles bear several similarities with other groups with long‐lasting symptoms.

Hemispheric Asymmetry and Left and Right Manual versus Pedal Tapping during a Concurrent Cognitive Task

In the present experiment we investigated the effects of concurrent hemisphere-specific cognitive activity on manual and pedal tapping frequency in a dual-task interference paradigm. Typically, right-hand finger-tapping interference is observed during a verbal task, and left-hand interference is observed during a nonverbal task. This effect has theoretically been linked to the concept of competition for the same functional space within a hemisphere between two concurrently performed tasks. In the present study, the concept of functional space was examined by comparing finger-tapping with foot-tapping. The assumption was that finger-tapping should be more affected than foot-tapping to hemisphere-specific tasks, and especially a verbal task, considering the closer structural overlap between the cortical hand area and the speech area The experiment involved four tasks performed concurrently with either finger- or foot-tapping. The tasks were reading a text aloud, humming, watching slides with nonsense-syllables, and watching slides with visuospatial patterns. The subjects were 20 right-handed males. The results did not support the hypothesis of competition for functional space.

Characterization of health complaints before and after removal of amalgam fillings — 3-year follow-up

Abstract Objective. Some patients attribute health complaints to amalgam fillings and report improvement of health after replacement of amalgam fillings. The aim of the present study was to characterize the changes of different health complaints after replacement of amalgam fillings and compare with an external reference group from the general population. Materials and methods. The study group included 20 patients with health complaints attributed to amalgam fillings who were participants in the treatment group of a clinical trial at the Norwegian Dental Biomaterials Adverse Reaction Unit. The patients were asked to indicate the intensity of local and general health complaints on numeric rating scales (0–10) before removal of amalgam fillings and at follow-up 3 years after removal. Data from the patient group were compared with data from an external reference group (n = 441). Results. Before treatment the mean intensity of complaints were on a higher level in the treatment group compared to the reference group. The most frequently reported complaints in the treatment group were gastrointestinal symptoms, fatigue, pain from muscles and joints, symptoms from ear/nose/throat and difficulty concentrating. From pre-treatment examination to the 3-year follow-up 20 of 23 health complaints decreased, being statistically significant for taste disturbances, pain from muscles and joints, gastrointestinal complaints, complaints from ear/nose/throat and fatigue. Conclusions. The inter-individual variation of intensities of health complaints was considerable and the reduction of health complaints varied for the different complaints. Several factors may be of importance for the observed reduction of complaint intensity.

To tell or not to tell, that is the question : Ethical dilemmas presented by norwegian psychologists in telephone counseling

Ethical dilemmas encountered by psychologists have previously been studied in surveys and as formal ethical complaints. No previous publications have been found in which data from an ethics counseling telephone service for psychologists has been analyzed. The present study examines ethical dilemmas, as presented by members of the Norwegian Psychological Association calling the Ethics Telephone Counseling Service (ETCS) from 2001 through 2003. Psychologists seek counseling for a range of ethical dilemmas. Ethical dilemmas concerning confidentiality are those most commonly presented. Dilemmas concerning integrity are also fairly common, whereas dilemmas concerning competence are rarely presented. The study shows virtually no difference in frequency and nature of consultation based on how long a psychologist has been licensed. This study also shows only minor gender differences in the use of the ETCS. Possible implications for ethics education as a continuous process are discussed.