Physical activity and associated factors in Australian women during pregnancy: A cross-sectional study.

ISSUE ADDRESSED: Whilst the benefits of regular physical activity during pregnancy are well known, the few studies conducted in Australian pregnant women suggest that most do not meet recommended exercise guidelines. The aim of this study was to determine the levels of physical activity, sedentary behaviours, and associated factors in Australian pregnant women. METHODS: A random sample of pregnant women (N = 780) of (mean [SD]) 31 (5) years of age completed a questionnaire describing weekly physical activity and sedentary behaviours. A number of potential risk factors, including socio-demographic characteristics and ethnicity, were investigated using logistic regression. RESULTS: Approximately one-third (34%) of women were classified as "active"; however, only 7% of women performed the recommended amount of physical activity according to Australian guidelines. Women reported (mean [95% CI]) sitting for 8 (7.8-8.2) hours and lying down during the day for 0.5 (0.5-0.6) hour while pregnant. Being university educated (OR [95% CI]) (2.87 [1.6-4.9]), in paid employment (2.12 [1.14-3.94]) and having a lower body mass index (0.91 [0.87-0.95]) were factors associated with being active. CONCLUSION: Australian women performed low levels of physical activity during pregnancy and spend long periods of time in sedentary behaviours. SO WHAT?: There is a strong need for a concerted health promotion strategy to endorse increased physical activity, along with a reduction in sedentary behaviours, during pregnancy to support better maternal outcomes in Australia.

"We are not there yet": perceptions, beliefs and experiences of healthcare professionals caring for women with pregnancy-related pelvic girdle pain in Australia.

BACKGROUND: Pregnancy-related pelvic girdle pain (PPGP) is a common condition worldwide. Women report being unprepared about PPGP, and state they receive little recognition and support from healthcare professionals. Situated within the Common-Sense Model and Convergent Care Theory, this study sought to gain a conceptual understanding of the perceptions, beliefs and experiences of healthcare professionals who provide routine care for women with PPGP in Australia. METHODS: A qualitative research design, using individual, semi-structured interviews with purposive sampling of healthcare professionals (N=27) consisting of doctors (N=9), midwives (N=9) and physiotherapists (N=9). Most participants were female (22/27) with a range of professional experience. An interview guide consisting of open-ended questions was used with a flexible and responsive approach. Thematic analysis was performed where interview data were transcribed, coded, grouped into meaningful categories and then constructed into broad themes. RESULTS: Four themes were identified: 1. Identity and impact of PPGP; 2. What works well?; 3. What gets in the way?; and 4. Quality care: What is needed? Healthcare professionals recognised PPGP as a common and disabling condition, which created a large impact on a woman's life during pregnancy. Stepped-level care, including education and physiotherapy intervention, was seen to be helpful and led to a positive prognosis. Barriers at patient, clinician and organisation levels were identified and led to consequences for women with PPGP not receiving the care they need. CONCLUSION: This study elucidates important implications for health care delivery. Acknowledging that PPGP is a common condition causing difficulty for many women, healthcare professionals identified strong teamwork and greater clinical experience as important factors in being able to deliver appropriate healthcare. Whilst healthcare professionals reported being committed to caring for women during pregnancy, busy workloads, attitudes towards curability, and a lack of formal education were identified as barriers to care. The findings suggest timely access, clear referral pathways and an integrated approach are required for best care practice for women with PPGP. A greater emphasis on the need for multidisciplinary models of care during pregnancy is evident.

"This is hard to cope with": the lived experience and coping strategies adopted amongst Australian women with pelvic girdle pain in pregnancy.

BACKGROUND: Women with pregnancy-related pelvic girdle pain (PPGP) report diminished ability to perform physical activities and experience higher rates of mood disorders, such as anxiety and depression, than pregnant women without PPGP. Despite these physical and psychological impacts, little is known about the lived experiences of PPGP amongst Australian women and the ways in which they cope. Situated within biographical disruption and social support theories, this study sought to gain a conceptual understanding of the experience and impact of PPGP on daily life, and how women cope with this condition during pregnancy. METHODS: A qualitative research design, situated within a phenomenological framework, using individual, semi-structured interviews consisting of open-ended questions was used with a flexible and responsive approach. Purposive sampling of pregnant women attending a single hospital included 20 participants between 14 and 38 weeks gestation, classified with PPGP as per recommended guidelines, with a mean (SD) age of 31.37 (4.16) years. Thematic analysis was performed where interview data was transcribed, coded, grouped into meaningful categories and then constructed into broad themes. RESULTS: Three themes were identified: 1. a transformed biography; 2. coping strategies; and 3. what women want. The pain experienced created a dramatic change in women's lives, making the pregnancy difficult to endure. Women utilised social support, such as family, to help them cope with pain, and a self-care approach to maintain a positive mindset and reduce stress. Although a few women received support from healthcare professionals, many reported a lack information on PPGP and limited societal recognition of the condition. Women wanted early education, personalised information and prompt referral to help them cope with PPGP. CONCLUSIONS: Findings from this study highlighted the complexity of living with PPGP as women attempted to deal with the unexpected impact on daily life by seeking support from partners and families, while also struggling with societal expectations. Although women with PPGP used a number of coping strategies, they sought greater support from healthcare professionals to effectively manage PPGP. These findings have important implications for the provision of health care to women living with PPGP. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry: ACTRN12618001423202 .

A scoping review on the methods of assessment and role of resilience on function and movement-evoked pain when experiencing a musculoskeletal injury.

BACKGROUND: Resilience refers to an individual's ability to maintain effective functioning, by resisting, withstanding or recovering from stressors or adversity, including pain associated with physical injury (J Clin Psychol Med Settings 28:518-28, 2021). The aim of this scoping review is to determine the role of resilience in the experience of movement-evoked pain (MEP) and return to functional activity following a musculoskeletal injury. METHODS: This review conformed to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews and the scoping review protocol of the Joanna Briggs Institute (JBI). Five databases and one grey literature database were searched using predetermined key words and index terms to capture published and unpublished records on the topic. Two authors independently screened the title and abstract of each record, with the full-text of eligible records being reviewed. Papers were eligible for inclusion if they examined the population, concept and context of interest, were written in English and the full text was available. Data were extracted from each eligible record to guide discussion of the available literature on this topic. RESULTS: Of 4771 records, 2695 articles underwent screening based on their title and abstract. After title and abstract screening 132 articles were eligible for full text review, with 24 articles included in the final analysis. This review identified that psychological resilience has primarily been investigated in the context of a range of age-related pathologies. The choice of functional and movement-evoked pain assessments in the included studies were often guided by the pathology of interest, with some being general or injury specific. CONCLUSION: This scoping review identified inconsistent conclusions regarding the role of resilience in the experience of MEP and the ability to return to function for older adults with a musculoskeletal injury. This scoping review highlights the need for longitudinal research to be conducted that allows a broader age range, including younger adults, to determine if multidimensional resilience may promote recovery form musculoskeletal injury.

Application of Caring Life-Course Theory to explore care needs in women with pregnancy-related pelvic girdle pain.

AIMS: To describe the care needs of women with pregnancy-related pelvic girdle pain based on the Caring Life-Course Theory. DESIGN: A descriptive qualitative research design. METHODS: Data were collected between November 2019 and February 2021 from 20 purposively selected pregnant women with pelvic girdle pain aged between 22 and 39 years in antenatal care at a tertiary hospital in Australia. Individual semi-structured interviews were recorded via a digital audio recorder and transcribed verbatim. Qualitative content analysis method was used to analyse the data. FINDINGS: Five broad themes were identified: pain is an added burden to pregnancy; knowledge is power to own what happens to me; engaging in self-help; care from others is useful; and pain deserves more attention from healthcare professionals. CONCLUSION: Caring Life-Course Theory presented a useful and applicable scaffold for describing care needs of pregnant women with pelvic girdle pain. The study revealed experiencing pelvic girdle pain led to additional care needs during pregnancy, highlighting the importance of self-management strategies and an appreciation of care from others to assist women in limiting the effects of the pain. Participants identified the need for more information and attention from healthcare professionals to be able to better manage their condition. IMPACT: This study presents a comprehensive picture of the change in care needs triggered by experiencing pelvic girdle pain during pregnancy. The findings have the potential to facilitate better care provision by considering novel methods of delivery, such as information and communication technology, whilst acknowledging the value placed on credible and trusted sources. Knowledge acquired through this study may be used by nurses and midwives, along with other healthcare professionals, to enhance the provision of comprehensive care that is acceptable to women with pelvic girdle pain during pregnancy.

Does surface slope affect dual task performance and gait? An exploratory study in younger and older adults.

An increased risk of falling is associated with changes in gait while dual-tasking. The degree to which gait stability is altered during walking is influenced by an individual's cognitive and postural capacity, and the difficulty of the presented tasks. However, it is unknown how greater walking task difficulty affects gait stability in younger and older adults when dual-tasking. The purpose of the current study was to determine the effect of walking task difficulty on gait stability in younger and older adults while performing a difficult audiospatial task. Ten younger [mean (SD) age 30.8 (6.6) years; 5 women] and 10 older [66.8 (5.7) years; 6 women] healthy adults walked on a treadmill at their preferred walking speed [younger 4.8 (0.4) ms-1, older 4.5 (0.5) ms-1) on either a level, or downhill slope both with and without responding to an audiospatial task. Step width, step width SD and mediolateral centre of mass displacement were calculated to determine changes in gait, and response time and accuracy were calculated to determine secondary task performance. Results indicated that older adults displayed a consistently greater step width (p ≤ 0.015) and maintained their mediolateral centre of mass displacement (p > 0.05) while walking downhill and responding to the audiospatial task, compared to downhill walking only. In contrast, younger adults maintained a regular step width during both level and downhill dual-tasking compared to level and downhill walking only (p > 0.05), however displayed a lower mediolateral centre of mass displacement during level dual-task walking compared to level walking only (p = 0.013). When the difficulty of the walking task was greater, older adults increased their step width, which increased their stability.

Does attention switching between multiple tasks affect gait stability and task performance differently between younger and older adults?

Gait stability and secondary task performance are affected by the need to share attention when dual-tasking. Further decrements may result from the need to switch attention between multiple secondary tasks. The aim of the current study was to determine the effects of attention switching upon gait stability and task performance in healthy younger and older adults. Ten healthy younger and ten healthy older adults walked on a treadmill at their preferred speed during three trials including: (1) baseline walking; (2) non-switching task walking, requiring response to an auditory-spatial or visual-spatial cue presented in an expected order; and (3) switching task walking, which required response to an auditory-spatial or visual-spatial cue presented in an unexpected order. Response time and accuracy, the margin of stability in the frontal (MoSML) and sagittal planes (MoSA: anterior, MoSP: posterior), step width and step length were calculated for non-switching and switching tasks. The MoSML, MoSA, MoSP, step width and step length during non-switching and switching tasks were normalized to baseline walking. Older adults took significantly longer to respond to cues and made more errors during the switching task compared to younger adults. Younger adults took narrower steps (p < 0.01) and displayed a reduction in MoSML (p < 0.01) during the switching task compared with the non-switching task. Conversely, older adults displayed no differences in MoSML between tasks. These findings suggest that attention switching results in different task prioritization strategies in younger and older adults during walking.

A comparison of gait stability between younger and older adults while head turning.

Head turning while walking may challenge stability by altering visual and vestibular information. Whether there are age-related changes that affect gait stability while head turning during walking remains unknown. The aim of the current study was to compare gait stability between younger and older adults immediately following a head turn while walking. Ten younger [mean (SD)] [23.4 (3.3) years] and ten older [68.8 (6.0) years] healthy adults walked on a treadmill at their preferred gait velocity and performed head turns by responding to a visual cue. The margin of stability (MoS) in the mediolateral (MoSML), anterior (MoSA) and posterior (MoSP) directions, foot placement (mean step length and width) and rotation of the head, trunk and pelvis were calculated for the four steps immediately following a cue to head turn and compared to walking only. Older adults increased their MoSML and younger adults increased their MoSP immediately following a head turn. However, older adults had a significantly greater MoSP than younger adults during this time. Older adults also had greater pelvic rotation velocity and a trend towards smaller head-on-trunk rotation compared to younger adults. Age does not compromise the stability of healthy older compared to younger adults immediately following or when completing a head turn. However, older adults may use a different motor strategy to perform a head turn to limit isolated movement of the head and the effects of a changing sensory frame of reference.

Repeat stereotactic radiosurgery for Cushing's disease: outcomes of an international, multicenter study.

Stereotactic radiosurgery (SRS) is frequently used for Cushing's disease (CD) after failed pituitary surgery. Management of patients with persistent CD after failed SRS is complex, as the alternative therapeutic options harbor significant risks. The outcomes of repeat pituitary radiosurgery, however, have not been described. We sought to determine the outcomes of repeat SRS in patients with CD. We pooled data from five institutions participating in the International Gamma Knife Research Foundation for patients with recurrent or persistent CD ≥ 12 months after initial SRS. Patients were included in the study if they had ≥ 6 months endocrine follow-up after repeat SRS. Twenty patients were included in the study. Repeat single-session SRS was performed 1.3-9.7 years after initial SRS. Median endocrine follow-up was 6.6 years (1.4-19.1 years). Median margin dose was 20 Gy (range 10.8-35 Gy). Endocrine remission after second SRS was noted in 12 patients (60%), with a median time to remission of 6 months (range 2-64 months). Biochemical recurrence occurred in two patients (17%) after initial remission. Overall, the cumulative rates of durable endocrine remission at 5 and 10 years were 47 and 53%, respectively. Two patients (10%) experienced adverse radiation effects, including transient visual loss and permanent diplopia. Repeat SRS achieves lasting biochemical remission in approximately half of patients with CD refractory to both prior microsurgery and SRS. Because of the morbidity of refractory or recurrent CD, repeat SRS should be considered for carefully selected patients with hypercortisolism confirmed one or more years after initial SRS.

A Comparison of Vertical Stiffness Values Calculated from Different Measures of Center of Mass Displacement in Single-Leg Hopping.

This study assessed the agreement between Kvert calculated from 4 different methods of estimating vertical displacement of the center of mass (COM) during single-leg hopping. Healthy participants (N = 38) completed a 10-s single-leg hopping effort on a force plate, with 3D motion of the lower limb, pelvis, and trunk captured. Derived variables were calculated for a total of 753 hop cycles using 4 methods, including: double integration of the vertical ground reaction force, law of falling bodies, a marker cluster on the sacrum, and a segmental analysis method. Bland-Altman plots demonstrated that Kvert calculated using segmental analysis and double integration methods have a relatively small bias (0.93 kN⋅m-1) and 95% limits of agreement (-1.89 to 3.75 kN⋅m-1). In contrast, a greater bias was revealed between sacral marker cluster and segmental analysis (-2.32 kN⋅m-1), sacral marker cluster and double integration (-3.25 kN⋅m-1), and the law of falling bodies compared with all methods (17.26-20.52 kN⋅m-1). These findings suggest the segmental analysis and double integration methods can be used interchangeably for the calculation of Kvert during single-leg hopping. The authors propose the segmental analysis method to be considered the gold standard for the calculation of Kvert during single-leg, on-the-spot hopping.

Transition from upright to greater forward lean posture predicts faster acceleration during the run-to-sprint transition.

BACKGROUND: Forward body lean and greater horizontal ground reaction force have been associated with being able to accelerate during running. However, kinematic features which may predict acceleration during the run-to-sprint transition have not been determined. The purpose of this study was to determine which kinematic changes occur in recreationally active adults and which kinematic features may predict greater acceleration during the run-to-sprint transition. METHODS: Forty-seven healthy adults completed straight line running along a 30 m track by running in at ∼4 m.s-1. A minimum of 20 trials were completed, with 25 % triggering a light to signal the participant to accelerate as fast as possible. Step characteristics (velocity, length, duration, cadence) and kinematics (neck, trunk, hip, knee and ankle angles and excursions) were determined using a radar gun and inertial measurement units, respectively. ANOVA was used to determine the step-to-step differences and a multiple linear regression was used to determine the relationship between kinematics and acceleration. RESULTS: There was an initial increase in trunk flexion angle during early acceleration (p < 0.001) with knee joint excursion significantly lower (p < 0.001) during loading and propulsion compared to the run-in steps. Greater acceleration was predicted using a stepwise linear regression by five variables including less neck flexion excursion and trunk flexion angle during swing of the 1st step, greater trunk flexion angle and extension excursion of the neck during propulsion of the 2nd step and greater hip flexion angle at foot strike of the 3rd step (r2 =0.804, p < 0.001). SIGNIFICANCE: Faster acceleration was observed when participants transitioned from an upright posture to greater forward trunk lean in the early phase of acceleration. Training the run-to-sprint transition, which was shown to have the greatest increase in velocity over the first 5 m, may be encouraged as a sports specific exercise.

The use of physical function capacity measures in the management of lower limb tendinopathy: A scoping review of expert recommendations.

BACKGROUND: Physical function capacity measures are recommended as outcome measures for people with lower limb tendinopathy. OBJECTIVE: (i) Explore measures of physical function capacity recommended by experts in lower limb tendinopathy (ii) the context they were used, (ii) identify recommended criteria for exercise progression and return to sport or activity. DESIGN: Scoping Review. METHOD: Three databases were searched using keywords for lower limb tendinopathy and physical function capacity to identify studies that outlined a progressive exercise rehabilitation program. A 15-item tool was used for data extraction. RESULTS: 26 studies were included, only eight recommended a physical function capacity measure. There were 10 physical function capacity measures identified for a range of lower limb tendinopathies including patellar (50%), Achilles (13%), proximal hamstring (13%), gluteal (13%), combined patellar and Achilles (13%). Pain was the most common criterion that was used to determine the progression of rehabilitation (96%), with physical function capacity measures rarely used (12%). CONCLUSION: Physical function capacity measures are used infrequently across expert recommended exercise rehabilitation programs. There remains a high reliance on pain as the criterion for progression of exercises during rehabilitation. There is a need to develop measures of physical function capacity to better inform and progress rehabilitation.

Agreement between hand therapists and hand surgeons in the management of adults with closed metacarpal fractures.

BACKGROUND: Hand therapists often work in roles which require an advanced level of experience as Advanced Scope Practitioners (ASP). However, it is not known whether clinical decisions are similar between hand therapists and surgeons when managing simple hand fractures. OBJECTIVES: To determine the level of agreement between (i) a hand therapist and five hand surgeons and (ii) three hand therapists, for the management of adults with closed metacarpal fracture(s). DESIGN: A prospective, blinded, crossover inter-rater reliability study. METHOD: Patient volunteers with closed metacarpal fracture(s) were assessed independently in the first study (n = 90) by a hand therapist and one of five hand surgeons and in the second study (n = 57) by three hand therapists in a randomised order, with each practitioner recording whether the patient participant should be managed conservatively, trialled with conservative or offered surgical treatment. The level of agreement between the hand therapist and hand surgeons was calculated using Cohen's kappa coefficient and between the three hand therapists by calculating Fleiss' Kappa. The observed agreement was also calculated as the proportion of cases for which the assessors had agreement for management. RESULTS: There was good agreement between the hand therapist and surgeons (k = 0.68; 95% CI: 0.537-0.831) and amongst the three hand therapists (k = 0.663; 95% CI: 0.554-0.773) in determining the management of adults with closed metacarpal fracture(s). CONCLUSIONS: Hand therapists and surgeons make similar management decision for patients with metacarpal fractures supporting the role of hand therapists as ASP.

Is Real-Time Ultrasound Reliably Able to Determine Kager's Fat Pad Motion during Walking?

The distal calcaneal wedge of the Kager's fat pad (KFP) has the mechanical role of lubricating the region between the Achilles tendon and calcaneus during ankle movements. The purpose of this study was to determine the reliability of real-time ultrasound (RTUS) in visualizing the motion of the KFP during walking in adults. Recordings obtained using RTUS (13-MHz linear array transducer, IOE 323, MyLab 70, Esoate, Genoa, Italy) of the Achilles enthesis region (N = 52) of 47 participants (ranging from 21-79 years in age) while walking on a motorised treadmill at their preferred speed were analysed by three blinded assessors. Motion of the KFP was rated on a 4-point Likert scale (normal to absent). There was good agreement (κ [95% confidence interval] = 0.646 [0.643-0.649]) among the three examiners, with very good agreement (0.823 [0.818-0.828]) when classifying the motion as normal. There was a poor correlation between the motion of the calcaneal wedge and participants' age (0.23-0.32). RTUS provides an adjunct to routine clinical examination to determine if there is normal motion of the calcaneal wedge during walking. This may be of benefit in patients with posterior heel pain for whom abnormal KFP motion is implicated.

Comparison of EMG signal of the flexor hallucis longus recorded using surface and intramuscular electrodes during walking.

The purpose of this study was to compare the use of intramuscular (iEMG) and surface (sEMG) electromyography electrodes to record flexor hallucis longus (FHL) muscle activity during walking, and describe the role of the FHL. Muscle activity was recorded in 12 participants using sEMG and iEMG during treadmill and overground walking. Inter-tester reliability for visual detection of onset and offset of muscle activity was high (ICC = 1.00). During the loading period, the number of bursts of muscle activity was statistically significantly greater using iEMG compared to sEMG when treadmill walking (p = 0.016), and the duration of muscle activity was significantly greater for iEMG (p = 0.01) on both walking surfaces. There were no differences for peak and mean root mean squared (p ≥ 0.07). The FHL activity observed during the loading period (heel strike to forefoot strike) supports the function of the FHL to act as a dynamic ankle stabiliser of the rearfoot, as well as contributing to propulsion during the latter part of stance. The choice of electrodes to detect FHL activity should be dependent on whether the loading and propulsive periods are of interest, and whether treadmill or overground walking will be examined.

Prevalence and Factors Associated with Pelvic Girdle Pain During Pregnancy in Australian Women: A Cross-Sectional Study.

STUDY DESIGN: Cross-sectional study conducted between December 2017 and October 2019. OBJECTIVE: To determine the prevalence and risk factors associated with pregnancy-related pelvic girdle pain (PPGP) in Australia. SUMMARY OF BACKGROUND DATA: PPGP is a common condition worldwide yet the prevalence and associated risk factors are not known in Australia. METHODS: A random sample of pregnant women (N = 780) of (mean [SD]) 31 (5) years of age between 14 and 38 weeks gestation attending ante-natal care in a tertiary referral hospital in Sydney, Australia was conducted. The main outcome measure was point-prevalence of PPGP as classified by recommended guidelines including a physical examination. A number of potential risk factors, including socio-demographic characteristics, country of birth, ethnicity, history of low back pain (LBP) and PPGP, family history of PPGP, occupational factors, and physical activity were investigated with logistic regression. RESULTS: The point-prevalence of PPGP in a random sample of 780 Australian women was 44% with the odds of having PPGP increasing with each additional week of gestation (odds ratio [OR]) (OR 1.02). Increasing parity (P = 0.03, OR 1.15), country of birth (P = 0.03), and greater duration of time spent standing (P = 0.009, OR 1.06) were associated with PPGP. The strongest predictors of PPGP were previous LBP and/or PPGP both pregnancy (P < 0.001, OR 4.35) and not pregnancy related (P < 0.001, OR 2.24), and a family history of PPGP (P < 0.001, OR 3.76). CONCLUSION: The prevalence of PPGP in Australian women was high with almost half the sample classified with PPGP, matching data reported worldwide. The identified risk factors associated with PPGP can be included in routine ante-natal care to screen women and identify those at risk of this common and disabling condition.Level of Evidence: 1.

Medial Gastrocnemius Muscle Activity during Single-Leg Hopping to Exhaustion.

This study described changes in leg muscle activation characteristics during exhaustive single-leg hopping. Twenty-seven healthy men performed trials (132 hops/min) to exhaustion, without a target height, to a target height with visual feedback and target height with tactile feedback. Mean muscle activation amplitude of the medial gastrocnemius (MG) decreased during the anticipatory period while duration of MG activity was maintained when hopping to a target height and contrasted the changes during hopping without a target height. Changes to MG activity were specific to whether the hopping height had been maintained or not. Changes during the anticipatory period of MG activity, indicative of adaptation in descending motor pathways, implicate utility of a motor learning strategy to allow completion of an exhaustive task.

Daxx inhibits muscle differentiation by repressing E2A-mediated transcription.

The basic helix-loop-helix (HLH) E2A transcription factors bind to DNA as homodimers or as heterodimers formed with other basic HLH factors, activate gene expression, and promote differentiation of muscle, lymphoid, neuronal, and other cell types. These E2A functions can be inhibited by the Id proteins, HLH factors that sequester E2A in non-DNA binding dimers. Here we describe the direct interaction of E2A with Daxx, a broadly expressed non-HLH protein previously associated with apoptosis and transcriptional repression. Daxx inhibits E2A function, but not via an Id-like mechanism; rather, it recruits histone deacetylase activity to E2A-dependent promoters. Increased Daxx expression during muscle differentiation inhibits E2A-dependent expression of key myogenic genes and reduces myotube formation, while decreased Daxx expression promotes myotube formation. These results identify a new mechanism for limiting E2A activity and establish a link between Daxx-mediated gene regulation and control of cellular differentiation.

Psychogenic movement disorders.

PURPOSE OF REVIEW: This review summarizes the progress made in the area of psychogenic movement disorders (PMDs) over the past 2 years, and a simplified classification of diagnostic certainty is proposed that incorporates electrophysiological assessment. RECENT FINDINGS: Functional magnetic resonance imaging studies have demonstrated altered blood flow in conversion disorders that may reflect changes in synaptic activity. Electrophysiological testing shows limitations in distinguishing between psychogenic and organic propriospinal myoclonus and dystonia. Recent evidence cautions against the uncritical acceptance of all cases of posttraumatic myoclonus and 'jumpy stump' as being organic in nature. 'Essential palatal tremor' is recognized as a rather heterogeneous group of tremors that includes psychogenic tremor. Two recent studies evaluating the long-term prognosis of psychogenic tremor differ in the degree of unfavorable outcome. Different groups of PMDs might have distinctive gait characteristics with prognostic, diagnostic, or therapeutic value. Two recent reviews provide comprehensive information on the understudied area of PMDs in children. SUMMARY: The diagnosis of PMDs should not be regarded as a diagnosis of exclusion. Careful clinical assessment is critical, and imaging or electrophysiological studies may provide important insights and confirmation of the diagnosis though some cases remain challenging and current assessments fail to provide needed clarification. Treatment is often delayed, contributing to a largely unfavorable long-term outcome. Well designed randomized control trials that validate and compare therapeutic options are urgently required.

What causes cell death in Parkinson's disease?

Currently, there is no proven neuroprotective or neurorestorative therapy for Parkinson's disease (PD). Several advances in the genetics of PD have created an opportunity to develop mechanistic-based therapies that hold particular promise for identifying agents that slow and even halt the progression of PD, as well as restore function. Here we review many of the advances in the last decade regarding the identification of new targets for the treatment of PD based on understanding the molecular mechanisms of how mutations in genes linked to PD cause neurodegeneration.