Predicting adoption of exposure therapy in a randomized controlled dissemination trial

The present study examined organizational, client, and therapist characteristics as predictors of use of and proficiency in exposure therapy (ET) after training. Therapists naïve to ET (N = 181) were randomized to: (1) online training (OLT), (2) OLT plus motivational enhancement (ME), or (3) OLT + ME plus a learning community. Twelve weeks after training, self-reported use of ET in clinical practice was high (87.5%) and therapists demonstrated moderate clinical proficiency. Use of ET was predicted by therapist degree, self-efficacy, and knowledge. Clinical proficiency was predicted by therapist anxiety sensitivity, attitudes, and knowledge, as well as organizational and client barriers. Several of these effects were moderated by training condition, indicating that therapists who received more comprehensive training were less impacted by barriers and showed enhanced adoption in the presence of facilitating factors. Overall, these results suggest that the primary barriers to the adoption of ET are therapist, not organizational or client, factors.     

Parkinson’s disease in general practice: Assessing knowledge, confidence and the potential role of education

In the context of an ageing population, Australian general practitioners (GPs) will be asked increasingly to manage challenging neurodegenerative conditions such as Parkinson’s disease (PD). This study sought to evaluate whether Australian GPs have been provided with sufficient training to effectively diagnose and manage PD, and to determine the extent to which a brief training seminar could improve knowledge and increase confidence. A baseline assessment was completed by 168 GPs in New South Wales and the Australian Capital Territory, and was re-administered following an educational seminar to 105 GPs. Australian GPs demonstrated significant knowledge gaps on the baseline assessment, scoring only 50% (standard deviation [SD] 15.5%). Post-seminar results showed significant improvement (p < 0.001) to 71.5% (SD 15%). Although following the seminar the vast majority reported increased confidence, there were some differential benefits between metropolitan and regional practitioners. These findings emphasise the need for continuing education in relation to PD in primary health care.     

Assessing relational schemas in parents of children with externalizing behavior disorders: Reliability and validity of the Family Affective Attitude Rating Scale

Direct observational assessment of parent-child interaction is important in clinical intervention with conduct-problem children, but is costly and resource-intensive. We examined the reliability and validity of a brief measure of parents' relational schemas (RSs) regarding their child. Children (aged 4 to 11 years) and their families receiving treatment at a clinic for externalizing behavior problems (n = 150) or mood/developmental disorders (n = 28) were assessed using a multi-method, multi-informant procedure. RSs were coded from Five-Minute Speech Samples (FMSS) using the Family Affective Attitude Rating Scale (FAARS), and were compared with directly observed parent-child interaction and questionnaire measures of family and parental dysfunction and conduct problems. Mothers' and fathers' RS scales were internally consistent and could be reliably coded in under 10 min. Less positive RSs and more negative RSs were associated with higher rates of child conduct problems, and were more characteristic of the speech samples of parents of children with externalizing disorders, compared with clinic control parents. RSs demonstrated some associations with parenting behavior and measures of family functioning and symptoms of parental psychopathology, and predicted conduct problems independently of observed parental criticism. The results demonstrate the reliability and validity of the FAARS assessment of parental RSs in clinic-referred families. This brief measure of parent-child dynamics appears well-suited to ‘real-world’ (i.e., community) clinical settings in which intensive methods of observation are often not feasible.     

Playback Theatre: Effects on students’ views of aggression and empathy within a forensic context

The objectives of this study were twofold: to better understand urban children and adolescents’ views of aggression and empathy and how those views may change when exposed to a Playback Theatre intervention; and to measure students’ understanding of the criminal justice/court system through the impact of instructive material on their comprehension levels. In an urban middle school, fifth and eighth grade students were randomly assigned (within age and gender) to experience a Playback Theatre intervention (N = 24) or to a video intervention control group (N = 23). All of the students received instruction on the basics of the criminal justice system. Also, students in both groups received pre- and post-intervention testing, including a comprehension test of the criminal justice/court system, an aggression questionnaire and an empathy scale. Students in both groups showed a significant increase in comprehension levels of the criminal justice/court system between assessments. Also, students’ ratings of tolerance for aggression were significantly reduced after exposure to Playback Theatre, however, students’ empathy scores were not significantly affected. The intervention of Playback Theatre yielded qualitative responses from students indicating that better perspective taking might be the mechanism underlying the effects of the Playback Theatre experience.     

Association of tissue plasminogen activator and plasminogen activator inhibitor polymorphism with myocardial infarction: A meta-analysis

Introduction

To investigate whether t-PA Alu repeat insertion/deletion (I/D) and PAI-1 4 G/5 G genetic variations are associated with the risk of MI.

Methods

We conducted a meta-analysis to assess the association between the t-PA I/D and PAI-1 4 G/5 G polymorphisms and risk of MI. We also performed subgroup analyses based on ethnicity (Caucasian, Asian, and African), gender and age. Forty one eligible studies including 12,461 cases and 14,993 controls were identified to evaluate the impact of PAI-1 4 G/5 G polymorphism on MI. Seven studies investigated the relationship between t-PA I/D and MI.

Results

This meta-analysis revealed that the PAI-1 4 G allele (4 G/4 G and 4 G/5 G genotype) was associated with an increased risk of MI compared with the 5 G allele in the overall population (OR = 1.094, 95% CI = 1.021 - 1.172, p = 0.011). The relative risks of MI for 4 G/4 G genotype was increased when compared to 5 G/5 G genotype and 5 G allele, with odds ratio at 1.157 (95% CI 1.015 - 1.320, p = 0.029) and 1.126 (95% CI = 1.015 - 1.249, p = 0.025). However, the results show that the 4 G/5 G polymorphism risk for MI was not associated with ethnicity stratification as Caucasian, Asian or African population. No substantial differences in the genotype distributions were observed in the MI group and control group along the lines of gender and age. After multivariable analysis t-PA I/D polymorphism showed no consistent association with MI.

Conclusions

This study suggests that the 4 G/5 G polymorphism of PAI-1 may be a risk factor for MI in overall populations.     

Frequency of reporting of adverse events in randomized controlled trials of psychotherapy vs. psychopharmacotherapy

Background

Psychopharmacology and psychotherapy are the two main therapies in mental health. It is common practice to consider adverse events (AEs) of medications, but it’s not clear this occurs with psychotherapy.

Aim

This study investigates the frequency with which reports of AEs occur in clinical trials using either psychopharmacology alone, psychotherapy alone, or combined approaches.

Methods

Forty-five articles of randomized trials published in high-impact journals were chosen from a Medline search, and separated into three groups of 15 articles: pharmacotherapy alone (M), psychotherapy alone (T) and combined studies that looked at the effect of both a psychotherapeutic (CT) and psychopharmacologic (CM) intervention. Criteria for what defines an AE were established and the papers were rated for mentions of AEs in papers as a whole and by each section.

Results

The χ²-analysis of AE mentions showed significant differences between the four study conditions in terms of each paper as a whole (χ²: 10.1, p < 0.018), and by section. Medication (M + CM) and psychotherapy papers (T + CT) were then combined into two groups to compare the odds that one was more likely to mention AEs than the other. Bivariate logistic regression yielded statistically significant odds ratios ranging from 9.33 to 20.99, with medications being far more likely to mention AEs.

Conclusion

We believe the difference in reports of AEs mirrors the attitudes researchers and providers. It’s critical to consider, and standardize the definition of, AEs in psychotherapy, and imperative to identify and address potential AEs in psychotherapy research.     

The assessment of positive dimension of the psychosis phenotype in college students

The Wisconsin Schizotypy Scales are one of the most used measuring instruments for the assessment of psychometric risk for psychosis. The main goal of the present study was to analyze the reliability of the scores and to provide new sources of validity evidence for the brief version of the Magical Ideation Scale (MIS-B) and the Perceptual Aberration Scale (PAS-B). The final sample was comprised of a total of 1349 university students divided into two subsamples (n1 = 710; M = 19.8 years; n2 = 639; M = 21.2 years). Results show that both measurement instruments have adequate psychometric properties under Classical Test Theory and Item Response Theory. Internal structure analysis of MIS-B and PAS-B, through exploratory and confirmatory factor analysis, yielded an essentially one-dimensional solution. Cronbach’s alpha coefficient for the total score of MIS-B ranged between 0.86 and 0.87, whereas for the PAS-B it ranged between 0.78 and 0.89. A total of 5 items showed a differential functioning for sex. The results indicate that the MIS-B and PAS-B are brief measurement instruments with adequate psychometric properties for the assessment of the positive dimension of the psychosis phenotype and could be used as screening tools in the detection of individuals at risk for psychosis in the general population.     

Improvement of fine motor skills in children with visual impairment: an explorative study

In this study we analysed the potential spin-off of magnifier training on the fine-motor skills of visually impaired children. The fine-motor skills of 4- and 5-year-old visually impaired children were assessed using the manual skills test for children (6-12 years) with a visual impairment (ManuVis) and movement assessment for children (Movement ABC), before and after receiving a 12-sessions training within a 6-weeks period. The training was designed to practice the use of a stand magnifier, as part of a larger research project on low-vision aids. In this study, fifteen children trained with a magnifier; seven without. Sixteen children had nystagmus. In this group head orientation (ocular torticollis) was monitored. Results showed an age-related progress in children's fine-motor skills after the training, irrespective of magnifier condition: performance speed of the ManuVis items went from 333.4 s to 273.6 s on average. Accuracy in the writing tasks also increased. Finally, for the children with nystagmus, an increase of ocular torticollis was found. These results suggest a careful reconsideration of which intervention is most effective for enhancing perceptuomotor performance in visually impaired children: specific ‘fine-motor’ training or ‘non-specific’ visual-attention training with a magnifier.     

Carvedilol recovers normal blood pressure variability in rats with myocardial infarction

Background

The aim of this study was to investigate the effects of chronic treatment with carvedilol in blood pressure (BPV) and heart rate (HRV) variability of rats with myocardial infarction (MI).

Methods

MI was produced in male rats by ligature of anterior interventricular branch of left coronary artery. Control rats were submitted to a sham surgery (SO). MI and SO rats were randomized to receive for 30 days placebo (Plac 0.5% metilcelulose) or carvedilol (Carv, 2 mg/Kg body weight/day, drinking water): SO-Plac (N = 10), SO-Carv (N = 10), MI-Plac (N = 12), MI-Carv (N = 13). Blood pressure (BP) was directly recorded in the awake animals and BPV was determined, in time (variance, mmhg²) and frequency domains by the autoregressive method. Statistical significance was set in P < 0.05. Data are median and interquartile range.

Results

No significant changes in HRV was observed in MI rats, while BPV showed significant decreasing of blood pressure variance (SO-Plac = 42.08 (39.21) mmHg² vs. MI-Plac = 21.67 (12.58) mmHg², P < 0.05), reversed by the Carv treatment (MI-Plac = 21.67 (12.58) vs. MI-Carv = 38.64 (29.25), P < 0.05). In the frequency domain analyses, MI reduced absolute and normalized LF component (LF (mmHg²): SO-Plac = 8.98 (14.84) vs. MI-Plac = 2.08 (4.84), P < 0.05; LF(nu): SO-Plac = 79.48 (45.03) nu vs. MI-Plac = 24.25 (40.67) nu, P < 0.05) and increased the normalized HF component of the BPV (SO-Plac = 20.51 (39.18) vs. MI-Plac = 60.51 (39.73). Carv treatment significantly attenuated the LF component fall.

Conclusion

Chronic treatment with carvedilol restored the variance of BPV altered by the MI.     

Interaction between homocysteine and lipoprotein(a) increases the prevalence of coronary artery disease/myocardial infarction in women: a case-control study

Introduction

Our aim was to investigate the association of elevated homocysteine (Hcy) and lipoprotein(a) Lp(a) with the prevalence of coronary artery disease (CAD) and myocardial infarction (MI) and to investigate their interaction in both genders.

Materials and methods

955 (male/female: 578/377) consecutive patients admitted for coronary angiography were enrolled in the study. Lp(a), Hcy, vitamin B12, folic acid, MTHFR C677T polymorphism and traditional risk factors were determined.

Results

619 patients had significant (≥ 50%) stenosis (CAD+) and 341 had MI (MI+). CAD-MI- cases (n = 302) were considered as controls. Adjusted Hcy levels were significantly elevated only in the female CAD + MI + group that was related to decreased vitamin B12 levels. Lp(a) was elevated in the CAD + MI + group of both genders. Folic acid levels and MTHFR T677 allele frequency did not show significant difference. Moderate hyperhomocysteinemia (Hcy > 15 μmol/L) or elevated Lp(a) (> 300 mg/L) increased the risk of CAD (OR 2.27, CI 1.36-3.80 and OR 1.64, CI 1.03-2.61, respectively) and MI (OR 2.52, CI 1.36-4.67 and OR 1.89, CI 1.06-3.38, respectively) only in women. Only simultaneous but not isolated elevation of Hcy and Lp(a) conferred a significant, 3.6-fold risk of CAD in females and even higher (11-fold) risk in young females, which suggested an interactive effect.

Conclusions

Moderate hyperhomocysteinemia or elevated Lp(a) level associated with a risk of CAD and MI only in women. While isolated elevation of one of the two parameters represented a mild risk of CAD, their combined elevation highly increased the risk in females. No such effect was observed in males.     

Eficacia del sistema ArmeoSpring en la fase crónica del ictus. Estudio en hemiparesias leves-moderadas

Objective

To evaluate the efficacy of a gravity-supported, computer-enhanced device (Armeo^®Spring) for upper limb rehabilitation in chronic stroke patients.

Material and methods

We included 23 chronic hemiparetic patients (chronicity: 328  ±  90.8 days; distribution: 17 men and 6 women) aged 54.6  ±  9.5 years, who had sustained ischaemic stroke (n = 12) or haemorrhagic stroke (n = 11). All patients completed 36 one-hour sessions using the Armeo^®Spring system. Arm movement was assessed at the beginning and end of the treatment programme and once more 4 months later. Main outcome measurements covered structure, activity, and function, as per the International Classification of Functioning, Disability and Health: Modified Ashworth Scale, Motricity Index (MI), Fugl-Meyer Assessment Scale (FM), Motor Assessment Scale (MAS), Manual Function Test (MFT), and Wolf Motor Function Test (WMFT).

Results

Repeated measures ANOVA showed significant improvement (time effect) for all function scales (P < .01 for FM and MI) and activity scales (P<.01 for MAS, MFT and WMFT-ability, and P < .05 WMFT-time) without significant changes in muscle tone. The post-hoc analysis (Bonferroni) showed different evolutionary patterns for function and activity measurements, and clear benefits related to Armeo^®Spring training, especially on activity scales.

Conclusions

Armeo^®Spring is an effective tool for rehabilitating the affected arm in patients with hemiparesis secondary to ictus, even in the chronic stage.     

Effectiveness of functional progressive resistance exercise training on walking ability in children with cerebral palsy: a randomized controlled trial

The objective of the study was to evaluate the effectiveness of functional progressive resistance exercise (PRE) training on walking ability in children with cerebral palsy (CP).Fifty-one ambulant children with spastic CP (mean age 10 years 5 months, 29 boys) were randomized to an intervention (n = 26) or control group (n = 25, receiving usual care). The intervention consisted of 12 weeks functional PRE circuit training, for 3 times a week. Main outcome measures were walking ability and participation. Secondary outcomes were muscle strength and anaerobic muscle power. Possible adverse outcomes were spasticity and passive range of motion (ROM). Muscle strength increased significantly in the training group compared to the control group, but walking ability, participation and anaerobic muscle power did not change. Spasticity and ROM remained unchanged, except for a significant decrease in rectus femoris length in the intervention group. It is concluded that twelve weeks of functional PRE-training does not improve walking ability, despite improved muscle strength.     

Tissue factor-induced Thrombin Generation in the Fasting and Postprandial State among Elderly Survivors of Myocardial Infarction

Introduction

Tissue factor (TF)-induced thrombin generation (TG) ex vivo has been suggested to be an important method to assess thrombotic risk. No studies have investigated the impact of postprandial lipemia on TF-induced TG. Since myocardial infarction (MI) is associated with elevated postprandial levels of triglycerides, we hypothesized a differential impact of postprandial lipemia on coagulation activation in MI-patients and healthy controls.

Material and Methods

Elderly survivors of acute MI (n = 44) and healthy age-and sex matched controls (n = 43) underwent a fat tolerance test (1 gram per kg body weight) to assess coagulation activation during postprandial lipemia.

Results

The incremental area under the curve (AUCi) for serum triglycerides was higher in MI-patients than in healthy age-and sex matched controls (5.64 ± 0.52 mmol/L?h and 3.94 ± 0.39 mmol/L?h, p = 0.012) during the postprandial phase. Subsequent endogenous activation of coagulation, assessed by FVIIa and thrombin generation (F1 + 2), was similar among groups and not related to levels of triglycerides during the postprandial phase. Healthy individuals had a gradual decline in TF-induced thrombin generation ex vivo, assessed by endogenous thrombin potential (ETP) (AUCi = - 542.4 ± 71.4 nM?min?h, p < 0.001), whereas MI-patients retained their ETP (AUCi = 127.4 ± 89.0 nM?min?h, p = 0.47) in plasma during the postprandial phase (p for group difference = 0.005).

Conclusions

MI-patients had elevated postprandial lipemia and retained their ability for TF-induced TG in plasma ex vivo in the postprandial phase, whereas the capacity gradually decreased in healthy individuals. Further studies are warranted to reveal underlying mechanism(s) and clinical implications.     

Learning curve for percutaneous endoscopic lumbar discectomy depending on the surgeon's training level of minimally invasive spine surgery

Purpose

To evaluate the differences of learning curve for PELD depending on the surgeon’ s training level of minimally invasive spine surgery.

Methods

We retrospectively reviewed the medical records of 120 patients (surgeon A with his first 60 patients, surgeon B with his first 60 patients) with sciatica and single-level L4/5 disk herniation who underwent PELD by the two surgeons with different training level of minimally invasive spine surgery (Group A: surgeon with little professional training of PELD; Group B: surgeon with 2 years of demonstration teaching of PELD).

Results

Significant differences were observed in the operation time (p = 0.000), postoperative hospital stay (p = 0.026) and reoperation rate (p = 0.050) between the two groups. In the operation time, significant differences were observed between the 1–20 patients group and 41–60 patients group in Group B (p = 0.041), but there were no significant differences among the 1–20 patients group, 21–40 patients group and 41–60 patients group in Group A. In the postoperative hospital stay, the significant differences were observed in the 1–20 patients group between Group A and Group B (p = 0.011). Significant differences were observed between preoperative and postoperative VAS back score, VAS leg score and JOA score. Higher improvement in the VAS leg score was observed in Group B than Group A (p = 0.031). In the rate of reoperation, the significant difference was observed between the 1–20 patients group and 41–60 patients group in Group A (p = 0.028) but there were no significant differences among the 1–20 patients group, 21–40 patients group and 41–60 patients group in Group B.

Conclusions

The surgeons’ training level of minimally invasive spine surgery was an important factor for the success of PELD, especially the demonstration teaching of PELD for the new minimally invasive spine surgeons.     

Effects of computerized match-to-sample training on emergent fraction-decimal relations in individuals with fragile X syndrome

Individuals diagnosed with fragile X syndrome (FXS), the most common known form of inherited intellectual disability, are reported to exhibit considerable deficits in mathematical skills that are often attributed to brain-based abnormalities associated with the syndrome. We examined whether participants with FXS would display emergent fraction-decimal relations following brief, intensive match-to-sample training on baseline relations. The performance profiles on tests of symmetry and transitivity/equivalence of 11 participants with FXS, aged 10-23 years, following baseline match-to-sample training were compared to those of 11 age- and IQ-matched controls with idiopathic developmental disability. The results showed that both groups of participants showed significant improvements in the baseline (trained) relations, as expected. However, participants with FXS failed to show significant improvements in the (untrained) symmetry and transitivity/equivalence relations compared to those in the control group. A categorical analysis of the data indicated that five participants with FXS and eight controls showed at least “intermediate” emergence of symmetry relations, whereas one individual with FXS and three controls showed at least intermediate emergence of transitivity/equivalence relations. A correlation analysis of the data indicated that improvements in the symmetry relations were significantly associated with improvements in the transitivity/equivalence relations in the control group (r = .69, p = .018), but this was not the case in the FXS group (r = .34, p > .05). Participant IQ was significantly associated with improvements in the symmetry relations in individuals with FXS (r = .60, p = .049), but not in controls (r = .21, p > .05). Taken together, these results suggest that brief, computerized match-to-sample training may produce emergent mathematical relations for a subset of children with FXS and developmental disabilities. However, the ability of individuals with FXS to form transitivity/equivalence relations may be impaired relative to those with idiopathic developmental disabilities, which may be attributed to neurodevelopmental variables associated with the syndrome.     

Magical ideation and hyperacusis

The subjective experience conferred by auditory perception has rarely been addressed outside of the studies of auditory hallucinations. The aim of this study is to describe the phenomenology of auditory experiences in individuals who endorse magical beliefs, but do not report hallucinations. We examined the relationship between subjective auditory sensitivity and a ‘psychotic-like’ thinking style. Hyperacusis questionnaire scores were compared between 25 high scoring participants on Chapman's magical ideation (MI) scale, 25 high scoring participants on Chapman's physical anhedonia scale and 25 control participants, pre-selected from a large student pool (n = 1289). The participants who obtained high scores on the MI scale rated their auditory sensitivity higher than the two other groups. Our results indicate that, in healthy subjects, subjective auditory sensitivity is associated with MI without the mediation by anxiety commonly observed in pathological cases. We propose that hyperacusis associated to high scores of MI may be a predispositional factor to deviant auditory experiences. The relative uncoupling of perception from auditory sensory input may result in a central hypersensitivity, which could play a role in triggering off the experience of auditory hallucinations.     

Anger induced by interferon-alpha is moderated by ratio of arachidonic acid to omega-3 fatty acids

Objective

Anger worsens in some patients during interferon-alpha (IFN-α) therapy. Elevated anger has also been associated with lower long-chain omega-3 (LCn − 3) fatty acid levels. We examined whether fatty acids could influence vulnerability to anger during IFN-α exposure.

Methods

Plasma arachidonic acid (AA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) levels were determined prior to IFN-α therapy by mass spectroscopy. Repeated-measure analyses examined the relationship between AA/EPA + DHA and the subsequent development of labile anger and irritability in 82 subjects who prospectively completed the Anger, Irritability, and Assault Questionnaire (AIAQ) during the first eight weeks of IFN-α therapy.

Results

Prior to IFN-α therapy, AA/EPA + DHA did not correlate with either labile anger or irritability. Pre-treatment AA/EPA + DHA did correlate with the subsequent maximal increase in labile anger during IFN-α therapy (r = 0.33; p = 0.005). Over time, labile anger increased more in subjects with above median AA/EPA + DHA ratios (p < 0.05). Of the 17 subjects ultimately requiring psychiatric intervention for anger, 14/17 had above-median AA/EPA + DHA ratios (p = 0.009). There was also an interaction with the tumor necrosis factor-alpha (TNF-α) promoter polymorphism (A-308G), such that only those with both elevated AA/EPA + DHA and the A allele had increased labile anger (p = 0.001). In an additional 18 subjects, we conversely observed that selective serotonin reuptake inhibitor treatment was associated with increased irritability during IFN-α therapy.

Conclusion

LCn − 3 fatty acid status may influence anger development during exposure to elevated inflammatory cytokines, and may interact with genetic risk for increased brain TNF-α. LCn − 3 supplements may be one strategy for minimizing this adverse side effect of IFN-α.     

Efficacy of modified constraint induced movement therapy in improving upper limb function in children with hemiplegic cerebral palsy: A randomized controlled trial

Purpose: The objective of this randomized single blind (outcome assessor) controlled trial was to evaluate the efficacy of 4 weeks of modified constraint induced movement therapy (mCIMT) in improving upper limb function in 3–8 years old children with hemiplegic cerebral palsy. Methods: Thirty-one children were randomly assigned to receive the mCIMT (N = 16) with conventional therapy or conventional therapy alone (N = 15). Children were evaluated three times (at enrollment, follow up at 4 weeks and 12 weeks). The primary outcome measure was difference in “change in mean total QUEST scores” at 4 weeks of intervention between the intervention and the control arm. Results: After 4 weeks of intervention, mCIMT group showed significant change in the affected upper limb in QUEST scores (10.7 ± 5.2 vs 1.4 ± 1.7, p < 0.001) and time (s) to complete nine-hole-pegboard test compared with control group [60(0–130) vs 5(−12 to 30), p < 0.001]. The improvement observed in upper limb function after 4 weeks of intervention persisted 8 weeks after discontinuation of intervention in mCIMT group. Conclusion: The modified constraint induced movement therapy appears to be effective in improving upper limb function in 3–8 years old hemiplegic cerebral palsy children.     

Compromised motor imagery ability in individuals with multiple sclerosis and mild physical disability: An ERP study

Background

Motor imagery (MI) impairment has been reported in individuals with multiple sclerosis (MS). The present study was designed to investigate neural evidence for MI impairment and its relationship to working memory in MS patients.

Methods

The study participants included 24 early stage MS patients (age: 22–40/mean = 32.7 years; M/F = 4/20; years since duration: 1–10/mean = 5.8) and 24 age-, gender-, and education-matched controls (age: 21–40/mean = 31.8 years; M/F = 5/19). Event-related potentials were recorded during a mental hand rotation task, in which participants were instructed to judge the laterality of hands displayed in different orientations. Furthermore, the Paced Auditory Serial Addition Test (PASAT) was used for assessment of working memory.

Results

At the behavioral level, MS patients were significantly less accurate and much slower (accuracy: 83.80 ± 7.72%; reaction time: 1665.95 ± 269.82 ms) than controls (accuracy: 88.35 ± 7.68%; reaction time: 1505.16 ± 225.11 ms). At the neural level, MS patients showed a significantly reduced amplitude (MS: 0.99 ± 0.89 μv, controls: 1.46 ± 1.00 μv) and delayed peak latency (MS: 458.45 ± 67.60 ms, controls: 417.91 ± 62.47 ms) at P3 for mental rotation effect. Moreover, there were significant correlations between individuals’ PASAT scores and performance of the hand rotation task.

Conclusion

The results of the present study demonstrate MI impairment in patients with MS at both the behavioral and neural level. Neuronal activity dysfunction (decreased and delayed activity) in patients with MS provides new insights into MI impairment. Furthermore, our findings suggest the contribution of working memory dysfunction to compromised MI ability in patients with MS.