Ophthalmic artery reversal predicts contralateral body weakness symptoms better than carotid Doppler velocity-preliminary results.

Background: The measurement of blood velocity in the carotid artery has been the most popular noninvasive method of identifying and classifying carotid stenosis for half a century. Carotid stenosis is an indicator of elevated risk of stroke; anatomic revascularization reduces the chance of stroke by more than half. Controversy persists on how patients with severe carotid stenosis should be selected for anatomic revascularization. Patients with a connected circle of Willis (coW) might not benefit from anatomic revascularization; patients with two segments missing in the coW are most likely to benefit from revascularization. Methods: Based on this analysis of data from carotid duplex examinations and transcranial Doppler examinations including ophthalmic artery (OA) direction in 28 patients, a refined carotid examination protocol is proposed. This refinement includes Doppler measurement of OA flow direction and documentation of internal carotid artery (ICA) bruit in addition to the adoption of an ICA peak systolic velocity (PSV) criterion exceeding 350 cm/s for identification of the patient most likely to benefit from carotid stenosis treatment. Results: Sensitivity and specificity of OA direction or carotid bruit are 84.6%±5.4%, 71.4%±2.1% and for PSV >350 cm/s are 84.6%±5.4%, 59.5%±2.3% for predicting contralateral body weakness. Conclusions: The proposed examination can be performed with the same duplex scanner and scan head currently used for carotid examinations with little additional time.

Early cardiovascular function and associated hemodynamics in adults with isolated moderate-severe traumatic brain injury: A pilot study.

BACKGROUND: While cardiac dysfunction has been described following traumatic brain injury (TBI), its association with systemic and cerebral hemodynamics is not known. We examined the contemporaneous relationship between early cardiac function with systemic and cerebral hemodynamic parameters after moderate-severe TBI. METHODS: Bedside transthoracic echocardiography (TTE) and transcranial Doppler (TCD) ultrasonography were performed within 24 h in patients > 18 years with isolated moderate-severe TBI. Systemic hemodynamic parameters were quantified using routine monitoring [heart rate and mean arterial pressures (MAP)] and calculation from echocardiographic data [stroke volume index (SVI), cardiac index (CI), and systemic vascular resistance index (SVRI)]. Systolic dysfunction was defined using TTE as global longitudinal strain (GLS) > -16%. Mean middle cerebral artery velocity (FVm) was the measure of cerebral hemodynamics and quantified using TCD. RESULTS: Among 15 patients [mean age 43 ±â€¯13 years, GCS 5 ±â€¯3, 73% male], 15 TTE and 15 TCD exams were performed simultaneously. Five (33%) patients had systolic dysfunction, with significantly worse GLS (median [IQR] -12.1% [-14.1, -12] vs. -19.1% [-19.9, -17.7], p = 0.004). Median (IQR) MAP was 97 (89, 107) mmHg, SVI (29.0 [20.5, 31.0] mL m-2), and CI (2.83 [2.05, 3.10] L/min m-2) were low to normal, while SVRI (2704 dyne sec/cm5 m-2 [2210, 4084]) was normal to high. None of the patients had abnormal TCDs. Higher GLS (reduced systolic function) was associated with lower SVI (r2 = 0.274, p = 0.03) but not other parameters. CONCLUSION: Systemic hemodynamic parameters were consistent with an early catecholamine-excess state. While reduced systolic function was associated with lower SVI, there was no relationship with reduced cerebral perfusion, possibly due to normal MAP.

The use of ultrasound for postoperative monitoring of cerebral bypass grafts: A technical report.

Duplex ultrasound and transcranial Doppler are valuable tools for post-operative monitoring of extracranial-intracranial cerebral bypass grafts. Here we describe our technique for the evaluation of both high-flow and low-flow cerebral bypass grafts over a nine year period. 186 bypass grafts were studied daily during the inpatient period between Jan 2005 and Dec 2014 after surgery for various cerebrovascular pathologies. There was a technical success rate of 97%. Duplex ultrasonographic flow measurements had excellent interobserver reliability with an intraclass correlation coefficient (ICC) of 0.89 (p=0.009). Technical nuances are highlighted and a brief discussion of pathology is undertaken.

Sagittal plane lumbar loading when navigating an obstacle and carrying a load.

The current study quantified lumbar loading while carrying an anterior load mass and navigating an obstacle. Eight healthy male participants walked down a walkway and crossed an obstacle under three randomised LOAD conditions; empty-box (2 KG), five kilogram (5 KG) and ten kilogram (10 KG). Each walk was assessed at two events: left foot mid-stance (LMS) and right toe-crossing (TC) to characterise any changes from approach to crossing. Measures of interest included: trunk pitch, L4/L5 joint moment, compression, joint anterior-posterior shear and erector spinae activation. Findings demonstrate that obstacle crossing extended posture by 50, 41, 44%, respectively for each carried load magnitude. Further, these results indicate that shear rather than compressive loading may be an important consideration during crossing due to increase by 8, 9, 22% from LMS to TC for each load magnitude tested. These results provide insight into sagittal lumbar loading when navigating an obstacle while carrying a load. Practitioner Summary: The risk of carrying while navigating obstacles on the lumbar spine is not completely understood. The forces at the lumbar spine while simultaneously carrying and obstacle crossing were analysed. Data indicate that carrying and obstacle crossing influence lumbar shear loads, thereby moderately increasing the relative risk at lumbar spine.

Factors affecting the risk of developing lower back musculoskeletal disorders (MSDs) in experienced and inexperienced rodworkers.

Injury and dropout rates during rodwork training appear to reflect difficulties encountered by apprentices adapting to increased physical demands of tying on slab, one of the rodworking tasks with the highest injury risk. Because experience influences work strategies, and consequently the risk of developing musculoskeletal disorders (MSDs), this study aimed to identify differences in work practices associated with tying rebar on slab, potentially relevant to back MSD development, in experienced and inexperienced rodworkers. Fourteen male rodworkers were recruited from either experienced (>2 years experience post apprenticeship), or inexperienced (<6 months experience) groups. Both tied an area with rebar laid on the ground. Trunk flexion/extension angles were measured. L4/L5 moments were estimated from T9 Erector Spinae EMG. Experienced workers were found to spend longer periods of time in trunk flexed postures, with lower peak L4/L5 moments. Our findings revealed practices associated with each group might have different implications on back health.

Monitoring flow in extracranial-intracranial bypass grafts using duplex ultrasonography: a single-center experience in 80 grafts over 8 years.

BACKGROUND: High-flow extracranial-intracranial (EC-IC) bypass is performed by using radial artery graphs (RAGs) or saphenous vein grafts (SVGs) for various pathologies such as aneurysms, ischemia, and skull-base tumors. Quantifying the acceptable amount of blood flow to maintain proper cerebral perfusion has not been well established, nor have the variables that influence flow been determined. OBJECTIVE: To identify the normative range of blood flow through extracranial-intracranial RAGs and SVGs as measured by duplex ultrasonography. Multiple variables were evaluated to better understand their influence of graft flow. METHODS: All EC-IC grafts performed at Harborview Medical Center from 2005 to 2012 were retrospectively reviewed for this cohort study. Daily extracranial graft duplex ultrasonography with flow volumes and transcranial graft Doppler were examined, as were short- and long-term outcomes. Both ischemic and hyperemic events were evaluated in further detail. RESULTS: Eighty monitorable high-flow EC-IC bypasses were performed over the 8-year period. Sixty-five bypasses were performed by using RAGs and 15 were performed with SVGs. The average flow was 133 mL/min for RAGs and 160 mL/min for SVGs (P = .25). For both RAG and SVG groups, the donor and recipient vessel selected significantly impacted flow. For the RAG group only, preoperative graft diameter, postoperative hematocrit, and postoperative date significantly influenced flow. A 1-week average of >200 mL/min was 100% sensitive to cerebral hyperemia syndrome. CONCLUSION: This study establishes the normative range of duplex ultrasonographic flow after high-flow EC-IC bypass, as well the usefulness and practicality of such monitoring as a surrogate to flow in the postoperative period.

A comparison of RULA, REBA and Strain Index to four psychophysical scales in the assessment of non-fixed work.

OBJECTIVES: The objective of this study was to evaluate the efficacy of three ergonomic assessment tools (EATs) (RULA, REBA and Strain Index (SI)) in the assessment of non-fixed work through comparison to four occupationally relevant Borg 10 psychophysical scales: Lifting Effort, Grasping Effort, Wrist Discomfort, and Low Back Discomfort. PARTICIPANTS: Fourteen male rodworkers participated in this study. The participants had at least six months experience and had no musculoskeletal injuries in the six months preceding their participation. METHODS: Psychophysical scale and video data were collected while participants performed non-fixed work on construction sites. Psychophysical and EAT outcome measure scores were calculated for a shortlist of tasks. RESULTS: It was found that the perceived Grasping Effort and Wrist Discomfort scales differentiated between the WMSD risks associated with rodworking tasks and SI was found to be more effective than RULA and REBA in the assessment of non-fixed work WMSD risks. CONCLUSIONS: Based on the findings of this study, it is suggested that SI be further evaluated for its ability to assess WMSD risks associated with non-fixed work tasks. SI presents results that have practical application to non-fixed occupations and differentiate between tasks based on the WMSD risks associated with the tasks.

Attentional demands associated with obstacle crossing while carrying a load.

The extent to which different locomotor tasks require cognitive control is not well characterized. In this article, the authors consider the potential increase in attentional demands associated with carrying an anterior load while clearing an obstacle. Nine healthy male volunteers participated in 80 walking trials, 20 in each of 4 conditions: 1 no load condition (NL) and 3 carrying conditions (2KG, 5KG, and 10KG). Of the 20 trials in each condition, 12 included a probe reaction time (PRT) test during lead limb obstacle crossing, which was used to measure cognitive load. A load-dependent increase in PRT was observed, with PRT in the 2KG condition being significantly greater than in the NL condition, and PRT in the 5KG and 10KG conditions being significantly greater than in the 2KG condition. These results suggested that cognitive load was increased when: (a) the obstacle was occluded from vision by the load, and (b) the magnitude of load was increased.

Clinical experience with transcranial Doppler ultrasonography as a confirmatory test for brain death: a retrospective analysis.

BACKGROUND: Transcranial Doppler (TCD) ultrasonography to demonstrate cerebral circulatory arrest (CCA) is a confirmatory test for brain death (BD). The primary aim of this retrospective study was to evaluate the practical utility of TCD to confirm BD when clinical diagnosis was not feasible due to confounding factors. Secondary aims were to evaluate the reasons for inability of TCD to confirm BD and to assess the outcome of patients not brain dead according to the TCD criteria. METHODS: TCD waveforms and medical records of all the patients examined to confirm suspected BD between 2001 and 2007, where clinical diagnosis was not possible, were analyzed. BD was diagnosed based on CCA criteria recommended by the Task Force Group on cerebral death of the Neurosonology Research Group of the World Federation of Neurology. Final outcome of patients and the use of other ancillary tests were noted. RESULTS: Ninety patients (61 males), aged 40 ± 21 (range 3-84) years underwent TCD examination for confirmation of suspected BD. TCD confirmed BD in 51 (57%) patients and was inconclusive in 38 (43%), with no flow signals on the first examination in 7 (8%) patients and the waveform patterns in 31 (35%) being inconsistent with BD. Fourteen of the 19 patients who had CCA pattern in at least one artery but did not meet all the criteria for BD were subsequently found brain dead according to SPECT/clinical criteria or suffered cardiovascular death. CONCLUSION: Using the conventional criteria, TCD confirmed BD in a large proportion, of patients where clinical diagnosis could not be made. The presence of CCA pattern in one or more major cerebral artery may be prognostic of unfavorable outcome, even when BD criteria are not satisfied.