Biomechanical assessment with electromyography of post-stroke ankle plantar flexor spasticity

Spasticity has been defined as a motor disorder characterized by a velocity-dependent increase in tonic stretch reflex (muscle tone). Muscle tone consists of mechanical-elastic characteristics, reflex muscle contraction and other elements. The aims of this study were to determine whether to assess spasticity quantitatively, and to characterize biomechanical and electromyographic spasticity assessment parameters. These assessment parameters were described by investigating the correlation between clinical measures and the response to passive sinusoidal movement with consecutive velocity increments. Twenty post-stroke hemiplegic patients and twenty normal healthy volunteers were included in the study. Five consecutive sinusoidal passive movements of the ankle were performed at specific velocities (60, 120, 180, and 240 degrees/ sec). We recorded the peak torque, work, and threshold angle using a computerized isokinetic dynamometer, and simultaneously measured the rectified integrated electromyographic activity. We compared these parameters both between groups and between different velocities. The peak torque, threshold angle, work, and rectified integrated electromyographic activity were significantly higher in the post-stroke spastic group at all angular velocities than in the normal control group. The threshold angle and integrated electromyographic activity increased significantly and linearly as angular velocity increased, but the peak torque and work were not increased in the post-stroke spastic group. Peak torque, work, and threshold angle were significantly correlated to the Modified Ashworth scale, but the integrated electromyographic activity was not. The biomechanical and electromyographic approach may be useful to quantitatively assess spasticity. However, it may also be very important to consider the different characteristics of each biomechanical parameter.     

Pretreatment of low dose radiation reduces radiation-induced apoptosis in mouse lymphoma (EL4) cells

Induction of an adaptive response to ionizing radiation in mouse lymphoma (EL4) cells was studied by using cell survival fraction and apoptotic nucleosomal DNA fragmentation as biological end points. Cells in early log phase were pre-exposed to low dose of γ-rays (0.01 Gy) 4 or 20 hrs prior to high dose γ-ray (4, 8 and 12 Gy for cell survival fraction analysis; 8 Gy for DNA fragmentation analysis) irradiation. Then cell survival fractions and the extent of DNA fragmentation were measured. Significant adaptive response, increase in cell survival fraction and decrease in the extent of DNA fragmentation were induced when low and high dose γ-ray irradiation time interval was 4 hr. Addition of protein or RNA synthesis inhibitor, cycloheximide or 5,6-dichloro-1-β-d-ribofuranosylbenzimidazole (DRFB), respectively during adaptation period, the period from low dose γ-ray irradiation to high dose γ-ray irradiation, was able to inhibit the induction of adaptive response, which is the reduction of the extent DNA fragmentation in irradiated EL4 cells. These data suggest that the induction of adaptive response to ionizing radiation in EL4 cells required both protein and RNA synthesis.     

The predictive value of lesion and disconnectome loads for upper limb motor impairment after stroke

Neurological Sciences - The putative effect of lesion-induced brain damage on post-stroke upper limb motor impairment can be estimated by overlaying a patient's lesion or its surrogate with key...     

Diagnostic approach and treatment strategy in tachycardia-induced cardiomyopathy

BACKGROUND: Due to the absence of differential guidelines for heart failure with tachyarrhythmia, it is difficult to diagnose tachycardia-induced cardiomyopathy (TIC) at the initial visit. Furthermore, clinical outcomes of rate versus rhythm control in TIC are unclear. HYPOTHESIS: Because the etiology of TIC is different from dynamic cardiomyoplasty (DCMP), differential parameters may be present. METHODS: We assessed 21 patients with TIC (15 men; mean age, 50+/-14 years) and 21 control patients with idiopathic DCMP. We assessed clinical courses, echocardiographic parameters, as well as outcomes by treatment. RESULTS: In the TIC group, the related tachyarrhythmias were atrial fibrillation (n=12), atrial flutter (n=5), atrial tachycardia (n=3) and paroxysmal supraventricular tachycardia (n=1). After treatment, all patients became asymptomatic and the ejection fraction (EF) improvement (DeltaEF>or=15%) was observed in all patients (left ventricular ejection fraction [LVEF], 30+/-11%initial versus 58+/-6%last). In the idiopathic DCMP group, no patient showed EF improvement (EF increase相似文献   

Bone Cement Dislodgement: One of Complications Following Bone Cement Augmentation Procedures for Osteoporotic Spinal Fracture

Bone cement augmentation procedures have been getting more position as a minimally invasive surgical option for osteoporotic spinal fractures. However, complications related to these procedures have been increasingly reported. We describe a case of bone cement dislodgement following cement augmentation procedure for osteoporotic spinal fracture by reviewing the patient''s medical records, imaging results and related literatures. A 73-year-old woman suffering back and buttock pain following a fall from level ground was diagnosed as an osteoporotic fracture of the 11th thoracic spine. Percutaneous kyphoplasty was performed for this lesion. Six weeks later, the patient complained of a recurrence of back and buttock pain. Radiologic images revealed superior dislodgement of bone cement through the 11th thoracic superior endplate with destruction of the lower part of the 10th thoracic spine. Staged anterior and posterior fusion was performed. Two years postoperatively, the patient carries on with her daily living without any significant disability. Delayed bone cement dislodgement can occur as one of complications following bone cement augmentation procedure for osteoporotic spinal fracture. It might be related to the presence of intravertebral cleft, lack of interdigitation of bone cement with the surrounding trabeculae, and possible damage of endplate during ballooning procedure.