Effect of strontium citrate on bone consolidation during mandibular distraction osteogenesis.

OBJECTIVES/HYPOTHESIS: Mandibular distraction osteogenesis (MDO) involves a lengthy consolidation phase where complications can occur. Strontium is an element that has been shown to improve bone healing. The objective of this study was to determine whether strontium citrate can be used to enhance bone healing during MDO in a rabbit model. STUDY DESIGN: Prospective animal model study. METHODS: Custom-made MDO devices were placed on 20 New Zealand White rabbits. After a 7-day latency period, distraction was performed at 1 mm/day for 5 days. The study group rabbits (n = 10) received oral strontium citrate; the other 10 rabbits served as controls. Mandibles were removed at the end of the consolidation period (4 weeks). Formation and healing of new bone were evaluated with microcomputed tomography, histology, and a three-point bending mechanical test. RESULTS: New bone formed in all animals, but the consolidation process was enhanced in rabbits that received strontium. The histological analysis showed that study group rabbits had more mature bone. Microcomputed tomographic images demonstrated significantly higher bone density for study group animals, and the three-point bending test results demonstrated that the maximum load of the study group specimens was significantly greater than that of the control group mandibles. CONCLUSIONS: Strontium citrate improved the formation of new bone in the current rabbit model of MDO. The prolonged consolidation period may be shortened with strontium citrate, which may also have the potential to reduce complications. LEVEL OF EVIDENCE: NA Laryngoscope, 127:E212-E218, 2017.

Nationwide Doctor of Nursing Practice/Advanced Practice Registered Nurse Survey on Roles, Functions, and Competencies.

Educational preparation for advanced practice registered nurses (APRNs) continues to shift from the master's degree to the doctor of nursing practice (DNP). Previous analysis of the roles, functions, and competencies of APRNs by Honig, Smolowitz, and Smaldone (2011) identified differences in practice between Master's of Science in Nursing (MSN)- and DNP-prepared APRNs. The aim of this study was to use the survey instrument created by Honig et al. to survey DNP/APRNs from across the nation and gain insight into their roles, competencies, and functions. A convenience sample was drawn from DNP graduates from the 13 schools provided by the American Board of Comprehensive Care (ABCC) as eligible to sit for the ABCC examination. A total of 375 individuals from 33 states who reported that they were in practice as a nurse practitioner (NP) completed the survey. Differences between the initial study and this study indicated that DNP NPs currently provide care across settings but with less inpatient care, less subacute care, and less palliative care than was reported in the initial analysis. Pregnancy-related care was the least common clinical service provided. Overall, this research indicates that DNP NPs prepared in comprehensive care are providing direct clinical care across settings to complex patients consistent with the comprehensive care domains for the ABCC certification examination (Honig et al., 2011).

Startle activation is additive with voluntary cortical activation irrespective of stimulus modality.

When a startling acoustic stimulus (SAS) is presented during a simple reaction time (RT) task, it can trigger the prepared response through an involuntary initiation pathway. Previous research modelling the effects of presenting a SAS at various intervals following a non-startling auditory imperative signal (IS) suggested that involuntary initiation-related neural activation is additive with the voluntary initiation processes. The current study tested the predictions of this additive model when the SAS and IS are of different modalities by using a visual rather than auditory go-signal. Because voluntary RT latencies are delayed for visual stimuli compared to acoustic stimuli, it was hypothesised that the time course of additive activation would be similarly delayed. Participants performed 150 RT trials requiring a targeted 20° wrist extension task with a SAS presented 0-125 ms following a visual go-signal. Results were not different to those predicted by an additive model (p=0.979), yet were significantly different to those predicted by a horse-race model (p=0.037), indicating a joint contribution of voluntary and involuntary activation, even when the IS and SAS are of different modalities. Furthermore, the results indicated that voluntary RT differences due to stimulus modality are attributable to processes that occur prior to the increase in initiation-related activation.

Reduced motor preparation during dual-task performance: evidence from startle.

Previous studies have used a secondary probe reaction time (RT) task to assess attentional demands of a primary task. The current study used a startling acoustic stimulus (SAS) in a probe RT paradigm to test the hypothesis that attentional resources would be directly related to limitations in response preparation. Participants performed an easy or difficult version of a continuous primary task that was either primarily motor in nature (pursuit tracking) or cognitive (counting backward). Concurrently, participants responded to an auditory cue as fast as possible by performing a wrist extension secondary movement. On selected trials, the auditory cue was replaced with a SAS (120 dB), which is thought to involuntarily trigger a prepared response and thus bypass any response initiation bottleneck that may be present when trying to perform two movements. Although startle trials were performed at a shorter latency, both non-startle and startle probe trials resulted in a delayed RT, as compared to single-task trials, consistent with reduced preparation of the secondary task. In addition, analysis of SAS trial RT when a startle indicator was present versus absent provided evidence that the secondary task was at a lowered state of preparation when engaged in the cognitive primary task as compared to a motor primary task, suggesting a facilitative effect on preparatory activation when both the primary and secondary tasks are motoric in nature.

Startle neural activity is additive with normal cortical initiation-related activation.

The current study examined the process of response initiation in a simple reaction time (RT) task using a startling acoustic stimulus (SAS), which has been shown to trigger a prepared movement through an involuntary initiation pathway. The SAS was presented within the RT interval (concurrent with, and 25, 50, 75, 100, and 125 ms following the "go" signal), with the observed response latency used to examine the relative contributions of voluntary and involuntary activation to response initiation. Our results clearly indicate that both voluntary and startle-related initiation activation jointly contribute to the observed RT. The data support a model in which startle-related neural activity is additive with voluntary cortical initiation-related activation. This result also provides indirect support for the hypothesis that both voluntary and SAS-related involuntary activation involve a similar process of response output.

Pause time alters the preparation of two-component movements.

Targeted reciprocal aiming movements are pervasive in everyday life, but it is unclear how the timing parameters between task elements affect the preparation of these movements. This study used a loud (124 dB) startling acoustic stimulus (SAS) to probe how changes in the pause time between the outward and return components of a reciprocal aiming task affected the preparatory state of the motor system. Participants performed a visually guided wrist extension-flexion task to a target located at 20° from the start position and were instructed to pause the movement within the wrist extension target zone for either 50, 200, or 500 ms. A SAS was presented during 25 % of trials before either the onset of the wrist extension (out) or flexion (return) components of the task to determine how motor preparation was affected by task requirements. Results showed that the presentation of a SAS prior to the initial outward movement led to significantly earlier onsets of both the outward and return components (p < .05), indicating that the pause time in the planned action was pre-planned. For the longer (200, 500 ms) pause-time conditions, a SAS delivered prior to returning from the target region triggered the return portion of the movement early. These findings suggest that the shortest pause-time movement (50 ms) was preplanned as a single action, whereas for reciprocal movements with longer pause times at least the initial part of the movement and the timing of the pause were preplanned and integrated, while the return portion was more independent.

Characteristics and predictors of short-term outcomes in individuals self-selecting yoga or physical therapy for treatment of chronic low back pain.

OBJECTIVE: To compare clinical and demographic characteristics of individuals self-selecting yoga or physical therapy (PT) for treatment of chronic low back pain (cLBP) and to examine predictors of short-term pain and functional outcomes. DESIGN: Descriptive, longitudinal study. SETTINGS: A hospital-based clinic that offers modified integral yoga classes for cLBP and 2 outpatient PT clinics that offer exercise-based PT. PARTICIPANTS: Adults (n=53) with cLBP≥12 weeks: yoga (n=27), PT (n=26). METHODS: Yoga participants attended a 6-week, once weekly, 2-hour yoga class. PT participants underwent twice weekly, 1-hour individualized PT. Data were collected at baseline and at 6 weeks. Groups were compared by using χ2 and independent samples t-tests. Hierarchical linear regression was used to predict treatment outcomes. MAIN OUTCOME MEASURES: Disability (Roland Morris Disability Questionnaire), health status (Rand Short Form 36 Health Survey 1.0), pain bothersomeness (numerical rating scale), back pain self-efficacy (Back Pain Self-Efficacy Scale), and treatment satisfaction. RESULTS: At baseline, yoga participants were significantly less disabled (P=.013), had higher health status (P=.023), greater pain self-efficacy (P=.012), and less average pain bothersomeness (P=.001) compared with PT participants. At 6 weeks, when controlling for baseline group differences, greater pain self-efficacy was the strongest predictor for reduced pain and higher function for the entire sample. A significant group interaction by baseline pain self-efficacy predicted disability at 6 weeks. PT participants with low pain self-efficacy reported significantly greater disability than those with high pain self-efficacy. Yoga participants with low and high pain self-efficacy had similar disability outcomes. CONCLUSION: These findings strengthen evidence that self-efficacy is associated with cLBP outcomes, especially in individuals self-selecting PT. Further research to evaluate outcomes after yoga and PT in participants with low pain self-efficacy is needed.

High frequency stimulation of the mamillothalamic tract for the treatment of resistant seizures associated with hypothalamic hamartoma.

We investigate the clinical outcome from stimulation of the mamillothalamic tract in two patients with intractable epilepsy secondary to hypothalamic hamartomas. One patient has a left-sided and the other a right-sided tumor. Both patients presented with a history of gelastic and complex partial seizures resistant to multiple antiepileptic drugs. Both patients underwent insertion of a single deep brain-stimulating electrode ipsilateral to the site of the tumor, lying adjacent to the mamillothalamic tract. Postoperatively they both had a significant reduction in seizure frequency, with one patient being seizure free for the last 10 months. An improvement in mood was reported by the patient's primary carers and demonstrated on quality of life questionnaires.