Incidence,timing, and predictors of valve dislodgment during TAVI with the medtronic corevalve system

Objectives : To determine the incidence, timing and predictors of periprocedural valve dislodgment with the Medtronic Corevalve System (MCS). Background : Periprocedural valve dislodgment may occur during transcatheter aortic valve implantation (TAVI). Methods : Ninety‐eight consecutive patients underwent TAVI with the MCS after a comprehensive baseline assessment including invasive angiography, echocardiography, and Multi‐Slice Computed Tomography (MSCT). The invasive monitoring charts and angiographic studies of all TAVI procedures were reviewed to determine the incidence and timing of valve dislodgment. Results : Valve dislodgment occurred in 18 patients. Patients with valve dislodgment had a larger Aortic Valve Area (0.76 ± 0.25 cm² vs. 0.61 ± 0.19 cm², P = 0.007), lower mean transaortic gradient (37.65 ± 14.62 mm Hg vs. 47.11 ± 16.08 mm Hg, P = 0.03) and significantly less aortic root calcification (Agatston score median 1951 AU (IQR, 799–3103) vs. 3289 AU (IQR 2097–4481), P = 0.016). A lower aortic root calcium score (Agatston score < 2359 AU) was the single independent predictor for valve dislodgment (OR 3.10, 1.09–8.84). After valve dislodgment, the valve could be successfully retrieved and implanted in the proper anatomic location in all cases. Valve dislodgment was associated with a lower incidence of post‐procedural AR ≥ 2 (11.1% vs. 34.6%, P = 0.05). There were no relevant procedural or clinical implications to valve dislodgment. Conclusions : The incidence of periprocedural valve dislodgment was 18% in these series. Less aortic root calcification appeared the single independent predictor. © 2011 Wiley Periodicals, Inc.     

Electrodeposited nickel–graphene nanocomposite coating: effect of graphene nanoplatelet size on its microstructure and hardness

In this study, the effect of graphene nanoplatelet (GNP) size on the microstructure and hardness of the electrodeposited nickel–graphene nanocomposite coatings were investigated. GNPs with different sizes were prepared by using a high energy ball milling technique. The experimental result revealed the high energy ball milling technique could reduce the size, increase the surface area, and improve the dispersion ability of GNPs. The microstructure, hardness, and components of the nanocomposite coatings were greatly affected by GNP sizes. The highest microhardness was measured to be 273 HV for the nanocomposite coatings containing 5 h-milled GNPs, which is increased up to ∼47% compared to pristine Ni coating. The enhancement in the hardness is attributed to the uniform dispersion of the small GNP sizes inside the Ni matrix and the Ni grain size reduction when using milled GNPs.

The effect of graphene nanoplatelet size on the microstructure and hardness of electrodeposited nickel–graphene nanocomposite coatings was investigated.     

Locomotor Training and Muscle Function After Incomplete Spinal Cord Injury: Case Series

Abstract

Background/Objective: To determine whether 9 weeks of locomotor training (LT) results in changes in muscle strength and alterations in muscle size and activation after chronic incomplete spinal cord injury (SCI). Study Design: Longitudinal prospective case series.

Methods: Five individuals with chronic incomplete SCI completed 9 weeks of LT. Peak isometric torque, torque developed within the initial 200 milliseconds of contraction (Torque₂₀₀), average rate of torque development (ARTD), and voluntary activation deficits were determined using isokinetic dynamometry for the knee-extensor (KE) and plantar-flexor (PF) muscle groups before and after LT. Maximum muscle crosssectional area (CSA) was measured prior to and after LT.

Results: Locomotor training resulted in improved peak torque production in all participants, with the largest increases in the more-involved PF (43.9% ± 20.0%), followed by the more-involved KE (21.1% ± 12.3%). Even larger improvements were realized in Torque200 and ARTD (indices of explosive torque), after LT. In particular, the largest improvements were realized in the Torque200 measures of the PF muscle group. Improvements in torque production were associated with enhanced voluntary activation in both the KE and ankle PF muscles and an increase in the maximal CSA of the ankle PF muscles.

Conclusion: Nine weeks of LT resulted in positive alterations in the KE and PF muscle groups that included an increase in muscle size, improved voluntary activation, and an improved ability to generate both peak and explosive torque about the knee and ankle joints.     

The Thoracic Suspension Orthosis-A Seating Option For Patients With Pressure Ulcers

Abstract

Background/Objective: For patients with pressure ulcers, wound healing and prevention are important steps in reducing disability. Ulcers that fail to heal adequately may interfere with normal sitting. By relieving pressure, the thoracic suspension orthosis (TSO) may allow some patients with recurrent pressure ulcers to return to sitting and sit for longer periods.

Methods: In this retrospective case series, 6 patients with chronic pressure ulcers were managed with TSO. Each patient had at least one of the following: (1) severe, non-healing pressure ulcers unresponsive to standard therapy, (2) recurrent ulcers requiring multiple surgeries, (3) chronic pain associated with sitting, or (4) bilateral lower extremity amputation resulting in instability or ischial pain in the seated position.

Results: Each participant had a favorable functional outcome. Patients were able to resume modified sitting. Others were able to sit for longer periods. Some have used the TSO for long-term management.

Conclusions: A TSO is an additional seating option for patients with chronic pressure ulcer, chronic pain associated with sitting, or bilateral lower extremity amputation. It is recommended after less restrictive, conservative measures have failed. In some patients, it has been used in lieu of extreme surgical measures.     

Outcomes of a Home Cycling Program Using Functional Electrical Stimulation or Passive Motion for Children With Spinal Cord Injury: A Case Series

Abstract

Background/Objective: Children with spinal cord injury (SCI) are at risk for musculoskeletal and cardiovascular complications. Stationary cycling using functional electrical stimulation (FES) or passive motion has been suggested to address these complications. The purpose of this case series is to report the outcomes of a 6-month at-home cycling program for 4 children with SCI.

Methods: Two children cycled with FES and 2 cycled passively at home for 1 hour, 3 times per week.

Outcome Measures: Data collected included bone mineral density of the left femoral neck, distal femur, and proximaltibia; quadriceps and hamstring muscle volume; stimulated quadriceps and hamstring muscle strength; a fasting lipid profile; and heart rate and oxygen consumption during incremental upper extremity ergometry testing.

Results: The 2 children cycling with FES and 1 child cycling passively exhibited improved bone mineral density, muscle volume, stimulated quadriceps strength, and lower resting heart rate. For the second child cycling passively, few changes were realized. Overall, the lipid results were inconsistent, with some positive and some negative changes seen.

Conclusions: This case series suggests that cycling with or without FES may have positive health benefits and was a practical home exercise option for these children with SCI.     

A Pilot Study of Factors Associated With Falls in Individuals With Incomplete Spinal Cord Injury

Abstract

Background/Objective: To determine factors associated with falls among a sample of ambulatory individuals with incomplete spinal cord injury (SCI).

Study Design: Cross-sectional mail survey.

Methods: A survey instrument of participant characteristics and fall-related variables was developed using relevant items from existing measures and was mailed to 221 individuals with incomplete SCI, who were identified from records of a large specialty hospital in the southeastern United States. Of the 221 prospective participants, 119 completed the questionnaire (54%). Multivariable logistic regression models were used to determine factors that were independently associated with having had a fall in the past year.

Results: After adjusting for covariates, having fallen in the past year was significantly (P < 0.05) associated with greater numbers of medical conditions (odds ratio [OR] = 1.3; 95% confidence interval [Cl] = 1.0-1.7), having arthritis (OR = 3.4, 95% Cl = 1.2-9.6), experiencing dizziness (OR = 5.6, 95% Cl = 1.1-27.7), greater numbers of days with poor physical health (OR = 1.1; 95% Cl = 1.0-1.3), and the restriction of community activities because of fear of falling (OR = 1.5, 95% Cl = 1.1-2.1). The multivariable models also showed that the odds of having fallen were significantly lower among those with better current perceived physical health (OR = 0.5; 95% Cl = 0.3-0.9), those with better perceived health compared to a year ago (OR = 0.4; 95% Cl = 0.2-0.8), individuals who exercised more frequently (OR = 0.2; 95% Cl = 0.1-0.7), and those who used a walker (OR = 0.3; 95% CI = 0.1-0.9).

Conclusions: Results suggest that interventions that address exercise frequency, walker use, and dizziness have promise for reducing falls for individuals with incomplete SCI.     

Spasticity,weakness, force variability,and sustained spontaneous motor unit discharges of resting spastic–paretic biceps brachii muscles in chronic stroke

Introduction: The purpose of our study was to examine relations among spasticity, weakness, force variability, and sustained spontaneous motor unit discharges in spastic–paretic biceps brachii muscles in chronic stroke. Methods: Ten chronic stroke subjects produced submaximal isometric elbow flexion force on impaired and non‐impaired sides. Intramuscular EMG (iEMG) was recorded from biceps and triceps brachii muscles. Results: We observed sustained spontaneous motor unit discharges in resting biceps on iEMG. Spontaneous discharges increased after voluntary activation only on the impaired side. The impaired side had greater matching errors and greater fluctuations in isometric force. Spontaneous discharges were not related functionally to spasticity, force variability, or weakness. However, greater strength on the impaired side correlated with less force variability. Conclusion: Weakness rather than spasticity is a main factor interfering with voluntary force control in paretic–spastic biceps brachii muscles in chronic stroke. Muscle Nerve, 2013     

Levodopa‐induced dyskinesias in tyrosine hydroxylase deficiency

The objective of this study was to characterize levodopa (l‐ dopa)–induced dyskinesias in patients with tyrosine hydroxylase deficiency. Clinical observation was carried out on 6 patients who were diagnosed with tyrosine hydroxylase deficiency and were treated with escalating doses of l‐ dopa. All 6 patients showed l ‐dopa‐induced dyskinesias of variable intensity early in the course of treatment and regardless of the age of initiation. l ‐Dopa–induced dyskinesias were precipitated by increases in the dose of l ‐dopa and also by febrile illnesses and stress. They caused dysfunction and distress in 2 patients. The dyskinesias were improved by decreasing the l ‐dopa dose or by slowing its titration upward. Increasing the dose frequency was helpful in 2 patients, and introducing amantadine was helpful in another 2 patients. l ‐Dopa–induced dyskinesias are a common phenomenon in tyrosine hydroxylase deficiency. The current observations show that l‐ dopa–induced dyskinesias are frequent in a dopamine‐deficient state in the absence of nigrostriatal degeneration. Although l ‐dopa–induced dyskinesias in tyrosine hydroxylase deficiency are phenomenologically similar to those that occur in Parkinson's disease, they are different in a number of other respects, suggesting intrinsic differences in the pathophysiologic basis of l‐ dopa–induced dyskinesias in the 2 conditions. © 2013 Movement Disorder Society