Transcranial sonographic localization of deep brain stimulation electrodes is safe, reliable and predicts clinical outcome

In patients with deep brain stimulation (DBS), poor postoperative outcome or unexpected clinical change require brain imaging to check the lead location. Here, we studied safety, reliability and prognostic value of transcranial sonography (TCS) for DBS lead localization applying predefined TCS criteria. After measuring thermal effects of TCS and imaging artefact sizes of DBS lead using a skull phantom, we prospectively enrolled 34 patients with DBS of globus pallidus internus, ventro-intermediate thalamic or subthalamic nucleus. TCS had no influence on lead temperature, electrical parameters of DBS device or clinical state of patients. TCS measures of lead coordinates agreed with MRI measures in anterior-posterior and medial-lateral axis. Lead dislocation requiring reinsertion was reliably detected. Only patients with optimal lead position on TCS had favorable clinical 12-month outcome (>50% improvement), whereas unfavorable outcome (<25% improvement) was associated with suboptimal lead position. TCS may therefore become a first-choice modality to monitor lead location.     

脑深部电刺激术手术护理配合流程构建

总结80例帕金森病(PD)患者实施脑深部电刺激(DBS)手术的护理配合要点。目的:探讨手术配合要点,制定围手术期护理方案,优化传统手术护理配合方法,减少手术并发症,缩短手术时间,并对部分护理方法进行改进,旨在建立一套统一的标准化围手术期护理配合流程,提高临床疗效。方法:2015年1月至2017年7月行DBS手术的80例帕金森病患者进行细致、缜密的手术护理配合。采取术前评估制定帕金森患者术前评估表,术中密切配合并注意患者的安全管理,时刻关注患者肢体变化,及时做出反应,术后及时的回访。结果:80例患者共植入155侧电极,5例单侧,75例双侧,其中1例患者术后出现颅内血肿,经对症治疗后血肿消失,其余患者无颅内血肿、永久神经系统以及与手术相关并发症出现。结论:本组80例患者,术后早期均有不同程度的临床症状改善,专科护士配合,流程的优化提高了手术配合的熟练度,手术时间较前有所缩短,术者满意度提高。标准化围手术期护理配合流程对DBS治疗PD的疗效提高具有重要作用。     

脑深部电刺激术治疗帕金森病的进展与展望

脑深部电刺激术(deep brain stimulation,DBS)目前已成为国内外认可的帕金森病重要治疗方案。随着脑科学、手术方法、磁共振成像技术的不断发展,以及大量临床循证医学证据的逐渐完善,DBS治疗帕金森病在手术时机、靶点选择、症状控制、治疗机制、设备改进等方面均取得了较大的进展。但是,其在中轴运动症状和非运动症状的控制方面尚存在一些不足,设备、程控设置等方面也有待改进。     

The Study of Deep Brain Structures by Transcranial Duplex Sonography and Imaging Resonance Correlation

Transcranial duplex sonography (TCS) currently provides us with images of deep brain structures with sufficient resolution. We chose 2 sonographic quantitative parameters: the diameter of the third ventricle and a measurement not used by TCS to date, the midbrain area. Their reliability and reproducibility were assessed using magnetic resonance imaging (MRI) as the reference. A total of 99 patients free from neurodegenerative disorders were examined using TCS, and both parameters were measured by 2 independent explorers. Measurements of third-ventricle diameter by TCS showed very good correlation (r = 0.80) and agreement (ICC = 0.89) with measurements obtained by MRI. Measurements of the midbrain area by TCS also provided acceptable values with moderate correlation (r = 0.36) and agreement (ICC = 0.53). Interexplorer correlation values were good (ICC = 0.98 and 0.79 for the third ventricle and midbrain areas, respectively). Further studies will be required to determine the potential diagnostic usefulness of these parameters.     

Changes in viscoelastic properties of skeletal muscles induced by subthalamic stimulation in patients with Parkinson's disease

Background

Objective measurements would be useful to document the effect of deep brain stimulation in alleviating rigidity in patients with Parkinson's disease. The aim of the study was to examine the changes of viscoelastic properties in skeletal muscles as indicators of rigidity.

Methods

Six patients in an advanced stage of Parkinson's disease participated in the study. The study took place in the off-medication conditions after one night of drug withdrawal. The wrist rigidity was examined according to the Unified Parkinson's Disease Rating Scale in both sides. Myotonometry (Myoton) was used to determine stiffness and elasticity in extensor digitorum muscles bilaterally. The measurements were repeated and compared during the stimulation-on and stimulation-off periods.

Findings

A comparison of mean clinical motor scores revealed a significant improvement of parkinsonian symptoms due to brain stimulation. In particular, arm rigidity improved on average from 2.83 (1–4) in stimulation-off phase to 1.17 (0–2) in stimulation-on phase (P < 0.05). The mean values of elasticity and stiffness were not significantly different in stimulation-on and stimulation-off conditions. The patients with elevated clinical rigidity scores had higher mean values of stiffness (262.5 vs 211.0; P < 0.05) but the differences in elasticity were not significant.

Interpretation

Increased rigidity is associated with increased values of viscoelastic stiffness. This paper supports the use of myotonometry for objective quantification of rigidity and in the future, this tool could prove helpful for optimizing deep brain stimulation settings in patients with Parkinson's disease.     

Non-invasive Assessment of Elastic Modulus of Arterial Constructs during Cell Culture Using Ultrasound Elasticity Imaging

Mechanical strength is a key design factor in tissue engineering of arteries. Most existing techniques assess the mechanical property of arterial constructs destructively, leading to sacrifice of a large number of animals. We propose an ultrasound-based non-invasive technique for the assessment of the mechanical strength of engineered arterial constructs. Tubular scaffolds made from a biodegradable elastomer and seeded with vascular fibroblasts and smooth muscle cells were cultured in a pulsatile-flow bioreactor. Scaffold distension was computed from ultrasound radiofrequency signals of the pulsating scaffold via 2-D phase-sensitive speckle tracking. Young's modulus was then calculated by solving the inverse problem from the distension and the recorded pulse pressure. The stiffness thus computed from ultrasound correlated well with direct mechanical testing results. As the scaffolds matured in culture, ultrasound measurements indicated an increase in Young's modulus, and histology confirmed the growth of cells and collagen fibrils in the constructs. The results indicate that ultrasound elastography can be used to assess and monitor non-invasively the mechanical properties of arterial constructs.