The effect of time since stroke, gender, age, and lesion size on thalamus volume in chronic stroke: a pilot study.

Recent stroke studies have shown that the ipsi-lesional thalamus longitudinally and significantly decreases after stroke in the acute and subacute stages. However, additional considerations in the chronic stages of stroke require exploration including time since stroke, gender, intracortical volume, aging, and lesion volume to better characterize thalamic differences after cortical infarct. This cross-sectional retrospective study quantified the ipsilesional and contralesional thalamus volume from 69 chronic stroke subjects' anatomical MRI data (age 35-92) and related the thalamus volume to time since stroke, gender, intracortical volume, age, and lesion volume. The ipsi-lesional thalamus volume was significantly smaller than the contra-lesional thalamus volume (t(68) = 13.89, p < 0.0001). In the ipsilesional thalamus, significant effect for intracortical volume (t(68) = 2.76, p = 0.008), age (t(68) = 2.47, p = 0.02), lesion volume (t(68) = - 3.54, p = 0.0008), and age*time since stroke (t(68) = 2.46, p = 0.02) were identified. In the contralesional thalamus, significant effect for intracortical volume (t(68) = 3.2, p = 0.002) and age (t = - 3.17, p = 0.002) were identified. Clinical factors age and intracortical volume influence both ipsi- and contralesional thalamus volume and lesion volume influences the ipsilesional thalamus. Due to the cross-sectional nature of this study, additional research is warranted to understand differences in the neural circuitry and subsequent influence on volumetrics after stroke.

Molecular dynamics study of the mechanical loss in amorphous pure and doped silica.

Gravitational wave detectors and other precision measurement devices are limited by the thermal noise in the oxide coatings on the mirrors of such devices. We have investigated the mechanical loss in amorphous oxides by calculating the internal friction using classical, atomistic molecular dynamics simulations. We have implemented the trajectory bisection method and the non-local ridge method in the DL-POLY molecular dynamics simulation software to carry out those calculations. These methods have been used to locate the local potential energy minima that a system visits during a molecular dynamics trajectory and the transition state between any two consecutive minima. Using the numerically calculated barrier height distributions, barrier asymmetry distributions, relaxation times, and deformation potentials, we have calculated the internal friction of pure amorphous silica and silica mixed with other oxides. The results for silica compare well with experiment. Finally, we use the numerical calculations to comment on the validity of previously used theoretical assumptions.

Language changes coincide with motor and fMRI changes following upper extremity motor therapy for hemiparesis: a brief report.

To formally assess changes in language, affected UE movement, and motor functional activation changes via functional magnetic resonance imaging (fMRI) following participation in motor therapy without any accompanying language intervention. Pre-post case series. Five subjects with stroke exhibiting chronic, stable UE hemiparesis. The upper extremity section of the Fugl-Meyer (FM), the Western Aphasia Battery (WAB), and functional magnetic resonance imaging (fMRI), administered during performance of an affected UE motor task. All subjects were administered six weeks of repetitive task specific training (RTP), performed for approximately 2.5 hours per day, split into two sessions. For the first four weeks of the intervention period, RTP was administered every weekday, whereas, for the subsequent two weeks, RTP was administered 3 days/week. Epidural cortical stimulation was co-administered with the RTP via an electrode array and implanted pulse generator. For all sessions, one subject worked with a single therapist. Four weeks before and four weeks after the intervention period, all subjects were administered the FM, WAB, and fMRI. Three of the subjects exhibited clinically significant language changes on the WAB. These individuals exhibited the largest motor changes as measured by the FM. Functional MRI revealed distinct motor activation patterns in these subjects, characterized by more strongly right lateralized focal BOLD activity or a shift in activation toward the right hemisphere. Language changes appear to co-occur with motor changes after UE RTP. Understanding the underlying mechanisms of these findings may lead to more efficient and synergistic rehabilitative therapy delivery.

A Web-based communication aid for patients with cancer: the CONNECT Study.

BACKGROUND: Cancer patients and their oncologists often report differing perceptions of consultation discussions and discordant expectations regarding treatment outcomes. CONNECT, a computer-based communication aid, was developed to improve communication between patients and oncologists. METHODS: CONNECT includes assessment of patient values, goals, and communication preferences; patient communication skills training; and a preconsultation physician summary report. CONNECT was tested in a 3-arm, prospective, randomized clinical trial. Prior to the initial medical oncology consultation, adult patients with advanced cancer were randomized to the following arms: 1) control; 2) CONNECT with physician summary; or 3) CONNECT without physician summary. Outcomes were assessed with postconsultation surveys. RESULTS: Of 743 patients randomized, 629 completed postconsultation surveys. Patients in the intervention arms (versus control) felt that the CONNECT program made treatment decisions easier to reach (P = .003) and helped them to be more satisfied with these decisions (P < .001). In addition, patients in the intervention arms reported higher levels of satisfaction with physician communication format (P = .026) and discussion regarding support services (P = .029) and quality of life concerns (P = .042). The physician summary did not impact outcomes. Patients with higher levels of education and poorer physical functioning experienced greater benefit from CONNECT. CONCLUSIONS: This prospective randomized clinical trial demonstrates that computer-based communication skills training can positively affect patient satisfaction with communication and decision-making. Measurable patient characteristics may be used to identify subgroups most likely to benefit from an intervention such as CONNECT.

Delineation of motor and somatosensory thalamic subregions utilizing probabilistic diffusion tractography and electrophysiology.

PURPOSE: To employ and compare probabilistic diffusion tractography (PDT) for the explicit localization of connections from the thalamus to somatosensory cortex (S1) and primary motor cortex (M1) / supplementary motor area (SMA) with microelectrode electrophysiology in patients undergoing deep brain stimulation (DBS) surgery. MATERIALS AND METHODS: These tractography-derived connections were used to categorize voxels in the thalamus as corresponding to sensory or motor physiology. A novel model (referred to in this work as the "mixture" model) to delineate PDT-based thalamic functional subregions by thresholding fiber intensities, ie, connectivity-defined regions (CDR), was devised. Regions created using this classification method were compared with the most commonly used model (referred to in this work as the "separation" or "winner takes all" model) for defining CDRs. RESULTS: Electrophysiology data corresponded better for S1 CDRs created using the mixture model for both sensory and motor cells. Separation model CDRs showed poor correspondence against electrophysiology, with few sensory cells corresponding to the S1 separation model CDR. CONCLUSION: Mixture model-based CDRs may offer a significant improvement in delineation of functional subregions of subcortical structures.

An fMRI study of the differences in brain activity during active ankle dorsiflexion and plantarflexion.

Little is known regarding the differences in active cortical and subcortical systems during opposing movements of an agonist-antagonist muscle group. The objective of this study was to characterize the differences in cortical activation during active ankle dorsiflexion and plantarflexion using functional MRI (fMRI). Eight right-handed healthy adults performed auditorily cued right ankle dorsiflexions and plantarflexions during fMRI. Differences in activity patterns between dorsiflexion and plantarflexion during fMRI were assessed using between- and within-subject voxel-wise t-tests. Results indicated that ankle dorsiflexion recruited significantly more regions in left M1, the supplementary motor area (SMA) bilaterally, and right cerebellum. Both movements activated similar left hemisphere regions in the putamen and thalamus. Dorsiflexion activated additional areas in the right putamen. Results suggest that ankle dorsiflexion and plantarflexion may be controlled by both shared and independent neural circuitry. This has important implications for functional investigations of gait pathology and how rehabilitation may differentially affect each movement.

Using health communication best practices to develop a web-based provider-patient communication aid: the CONNECT study.

OBJECTIVE: Although there is broad consensus that careful content vetting and user testing is important in the development of technology-based educational interventions, often these steps are overlooked. This paper highlights the development of a theory-guided, web-based communication aid (CONNECT), designed to facilitate treatment decision-making among patients with advanced cancer. METHODS: The communication aid included an on-line survey, patient skills training module and an automated physician report. Development steps included: (1) evidence-based content development; (2) usability testing; (3) pilot testing; and (4) patient utilization and satisfaction. RESULTS: Usability testing identified some confusing directions and navigation for the on-line survey and validated the relevance of the "patient testimonials" in the skills module. Preliminary satisfaction from the implementation of the communication aid showed that 66% found the survey length reasonable and 70% found it helpful in talking with the physician. Seventy percent reported the skills module helpful and about half found it affected the consultation. CONCLUSION: Designing patient education interventions for translation into practice requires the integration of health communication best practice including user feedback along the developmental process. PRACTICE IMPLICATIONS: This developmental process can be translated to a broad array of community-based patient and provider educational interventions.