Engineering Interfacial Fast Ion Channels toward Highly Stable Zn Metal Batteries.

The development of aqueous zinc-ion batteries (AZIBs) is hindered by dendrites and side reactions, such as interfacial byproducts, corrosion, and hydrogen evolution. The construction of an artificial interface protective layer on the surface of the zinc anode has been extensively researched due to its strong operability and potential for large-scale application. In this study, we have designed an organic hydrophobic hybrid inorganic intercalation composite coating to achieve stable Zn2+ plating/stripping. The hydrophobic poly(vinylidene fluoride) (PVDF) effectively prevents direct contact between free water and the zinc anode, thereby mitigating the risk of dendrite formation. Simultaneously, the inorganic layer of vanadium phosphate (VOPO4·2H2O) after the insertion of polyaniline (PA) establishes a robust ion channel for facilitating rapid transport of Zn2+, thus promoting uniform electric field distribution and reducing concentration polarization. As a result, the performance of the modified composite PVDF/PA-VOP@Zn anode exhibited significant enhancement compared with that of the bare zinc anode. The assembled symmetric cell exhibits an exceptionally prolonged lifespan of 3070 h at a current density of 1 mA cm-2, while the full battery employing KVO as the cathode demonstrates a remarkable capability to undergo 2000 cycles at 5 A g-1 with a capacity retention rate of 78.2%. This study offers valuable insights into the anodic modification strategy for AZIBs.

A Refractory Electrical Storm after Acute Myocardial Infarction: The Role of Temporary Ventricular Overdrive Pacing as a Bridge to ICD Implantation.

An electrical storm (ES) is defined as the presence of at least three episodes of sustained ventricular tachycardia or ventricular fibrillation within 24 h. This patient had a previously known arterial hypertension, type II diabetes mellitus, and chronic kidney disease and has presented to the Emergency Department (ED) with symptoms of retrosternal chest pain lasting for several hours prior. The initial 12-lead electrocardiogram revealed ST segment elevation in the anterior leads (V1-V6). Emergent coronary angiography revealed an acute occlusion of the proximal left anterior descending artery (pLAD) and percutaneous coronary intervention was performed with successful implantation of one drug-eluting stent in the pLAD. On day 8 of hospitalization, the patient developed a refractory ES for which he received 50 DC shocks and did not respond to multiple lines of antiarrhythmic medications. Due to a failure of medical therapy, we decided to implant a temporary pacemaker and initiate ventricular overdrive pacing (VOP) that was successful in terminating ES. Following electrical stabilization, the patient underwent a successful ICD implantation. This case demonstrates that VOP can contribute to hemodynamic and electrical stabilization of a patient that suffers from refractory ES and this treatment modality might serve as a temporary bridge to ICD implantation.

An investigation into the dependence of virtual observation point-based specific absorption rate calculation complexity on number of channels.

PURPOSE: This study aims to find a relation between the number of channels and the computational burden for specific absorption rate (SAR) calculation using virtual observation point-based SAR compression. METHODS: Eleven different arrays of rectangular loops covering a cylinder of fixed size around the head of an anatomically correct voxel model were simulated. The resulting Q-matrices were compressed with 2 different compression algorithms, with the overestimation fixed to a certain fraction of worst-case SAR, median SAR, or minimum SAR. The latter 2 were calculated from 1e6 normalized random excitation vectors. RESULTS: The number of virtual observation points increased with the number of channels to the power of 2.3-3.7, depending on the compression algorithm when holding the relative error fixed. Together with the increase in the size of the Q-matrices (and therefore the size of the virtual observation points), the total increase in computational burden with the number of channels was to the power of 4.3-5.7. CONCLUSION: The computational cost emphasizes the need to use the best possible compression algorithms when moving to high channel counts.

Near Infrared Spectroscopy is not a Surrogate of Venous Occlusion Plethysmography to Assess Microvascular Resting Blood Flow and Function.

Near-infrared spectroscopy (NIRS) is a non-invasive technique that measures tissue perfusion using red blood cells oxygen saturation and venous occlusion plethysmography (VOP) is the gold standard to assess microvascular blood flow and function. The purpose of this study was to determine if NIRS can surrogate the microvascular blood flow assessment after an ischemic challenge obtained via VOP. Twenty apparently healthy subjects (10 males and 10 females), aged 18 to 35 years, were recruited for this single session study. NIRS probes were placed 40mm apart along the epicondylar muscles on the right forearm and on the tibialis anterior on the right lower leg, while VOP strain gauges were placed on the largest circumference on both right forearm and calf. Blood flow via VOP and NIRS variables (hemoglobin saturation (SO2), oxygenated hemoglobin (HbO2), and deoxyhemoglobin (HHb) slopes) were assessed before and after 5-min ischemic challenge. Person's correlations and intra-class correlations (ICC2k) were conducted for each of the NIRS variables vs VOP. There were moderate associations between of SO2 and HbO2 slopes and VOP (r = 0.59, p < 0.01 and r = 0.53, p < 0.05, respectively) at the lower body during resting conditions. There was a poor agreement between NIRS SO2 and VOP at the resting condition in the lower body (ICC2k = 0.45). There were no other associations between any of the other NIRS variables and VOP of the lower and upper body at resting or post-ischemic conditions. In conclusion, NIRS cannot surrogate VOP for measurements of microvascular blood flow at resting or post-ischemic conditions.

Effectiveness of Thalamic Ventralis Oralis Anterior and Posterior Nuclei Deep Brain Stimulation for Posttraumatic Dystonia.

Herein we report that the ventralis oralis anterior and posterior (Voa/Vop) nuclei of the thalamus may be effective alternative targets for deep brain stimulation (DBS) to improve posttraumatic dystonia when the globus pallidus interna is traumatically damaged. This patient presented at age 35 years with a clinical diagnosis of posttraumatic cervical and bilateral upper limb acquired dystonia resulting from intracerebral and intraventricular hemorrhage after a motorcycle accident at age 19 years. Due to a right globus pallidus interna traumatic lesion, conventional DBS targeting of the inferior basal ganglia was not possible; thus, the alternative Voa/Vop nuclei target was implanted. The patient realized significant benefit and at last follow-up 3 years postoperatively continued to endorse marked benefit and improvement of dystonia symptoms with minimal adverse effects from bilateral DBS implantation in the alternative targets of the Voa/Vop nuclei of the thalamus.

Post-processing algorithms for specific absorption rate compression.

PURPOSE: Compression of local specific absorption rate (SAR) matrices is essential for enabling SAR monitoring and efficient pulse calculation in parallel transmission. Improvements in compression result in lower error margin and/or lower number of virtual observation points (VOPs). The purpose of this work is to introduce two algorithms for post-processing of already compressed VOP sets. One calculates individual overestimation matrices for the VOPs to reduce overestimation, the other identifies redundant VOPs. METHODS: The first algorithm was evaluated for VOP sets calculated for three different transmit arrays with either 8 or 16 channels. For each array, two different overestimation matrices were used to generate the VOP sets. Each post-processed VOP set was evaluated using one million random excitation vectors and the results compared to the VOP set before post-processing. The second algorithm was evaluated by utilizing the same random excitation vectors and comparing the results after removal of the redundant VOPs with the results before removal to verify that these were identical. RESULTS: The first algorithm reduced the mean overestimation by up to four fifths compared to the original set, while keeping the number of VOPs constant. The second algorithm decreased the number of VOPs generated by a compression with Eichfelder and Gebhardt's algorithm by more than 40% in 40% of the investigated cases and by more than 20% in 73% of the investigated cases. CONCLUSION: Two post-processing algorithms are presented that enhance previously compressed VOP sets by improving the accuracy per number of VOPs.

Performance analysis of integrated RF microstrip transmit antenna arrays with high channel count for body imaging at 7 T.

The aim of the current study was to investigate the performance of integrated RF transmit arrays with high channel count consisting of meander microstrip antennas for body imaging at 7 T and to optimize the position and number of transmit elements. RF simulations using multiring antenna arrays placed behind the bore liner were performed for realistic exposure conditions for body imaging. Simulations were performed for arrays with as few as eight elements and for arrays with high channel counts of up to 48 elements. The B1+ field was evaluated regarding the degrees of freedom for RF shimming in the abdomen. Worst-case specific absorption rate (SARwc ), SAR overestimation in the matrix compression, the number of virtual observation points (VOPs) and SAR efficiency were evaluated. Constrained RF shimming was performed in differently oriented regions of interest in the body, and the deviation from a target B1+ field was evaluated. Results show that integrated multiring arrays are able to generate homogeneous B1+ field distributions for large FOVs, especially for coronal/sagittal slices, and thus enable body imaging at 7 T with a clinical workflow; however, a low duty cycle or a high SAR is required to achieve homogeneous B1+ distributions and to exploit the full potential. In conclusion, integrated arrays allow for high element counts that have high degrees of freedom for the pulse optimization but also produce high SARwc , which reduces the SAR accuracy in the VOP compression for low-SAR protocols, leading to a potential reduction in array performance. Smaller SAR overestimations can increase SAR accuracy, but lead to a high number of VOPs, which increases the computational cost for VOP evaluation and makes online SAR monitoring or pulse optimization challenging. Arrays with interleaved rings showed the best results in the study.

Local SAR compression algorithm with improved compression, speed, and flexibility.

PURPOSE: Local specific absorption rate (SAR) compression algorithms are essential for enabling online SAR monitoring in parallel transmission. A better compression resulting in a lower number of virtual observation points improves speed of SAR calculation for online supervision and pulse design. METHOD: An iterative expansion of an existing algorithm presented by Lee et al is proposed in this work. The original algorithm is used within a loop, making use of the virtual observation points from the previous iteration as the starting subvolume, while decreasing the overestimation with each iteration. This algorithm is evaluated on the SAR matrices of three different simulated arrays. RESULT: The number of virtual observation points is approximately halved with the new algorithm, while at the same time the compression time is reduced with speed-up factors of up to 2.5. CONCLUSION: The new algorithm improves the original algorithm in terms of compression rate and speed.

Local SAR compression with overestimation control to reduce maximum relative SAR overestimation and improve multi-channel RF array performance.

OBJECTIVE: In local SAR compression algorithms, the overestimation is generally not linearly dependent on actual local SAR. This can lead to large relative overestimation at low actual SAR values, unnecessarily constraining transmit array performance. METHOD: Two strategies are proposed to reduce maximum relative overestimation for a given number of VOPs. The first strategy uses an overestimation matrix that roughly approximates actual local SAR; the second strategy uses a small set of pre-calculated VOPs as the overestimation term for the compression. RESULT: Comparison with a previous method shows that for a given maximum relative overestimation the number of VOPs can be reduced by around 20% at the cost of a higher absolute overestimation at high actual local SAR values. CONCLUSION: The proposed strategies outperform a previously published strategy and can improve the SAR compression where maximum relative overestimation constrains the performance of parallel transmission.

La Vasculatura Sistémica En La Enfermedad Renal Crónica. Segunda Parte / Systemic Vasculature In Chronic Kidney Disease. Second Part

Resumen Existen cambios estructurales importantes de la pared arterial en, prácticamente, todas las etapas clínicas de la enfermedad renal crónica. Son un marcador pronóstico y, al mismo tiempo, un factor de progresión y de eventos, tanto cardiovasculares como renales. Es por ello que tener una estimación del daño vascular y, mejor aún, un diagnóstico adecuado es esencial. La evaluación vascular en la consulta clínica, mediante la determinación de la presión del pulso y el índice de presión arterial sistólica tobillo-brazo, sirven como una orientación inicial del daño arterial de estos pacientes. Hoy podemos valorar, de manera accesible, las lesiones estructurales de las arterias mediante la cuantificación y caracterización, por ecografía vascular, de las placas ateroscleróticas de carótidas y femorales y por la velocidad de onda del pulso. En la gran mayoría de los pacientes renales la velocidad de onda del pulso está muy aumentada, comparada con poblaciones sanas, como consecuencia de múltiples mecanismos patogénicos. Las alteraciones vasculares, tanto de los grandes vasos como de la microcirculación, están fuertemente vinculados con la progresión de la enfermedad renal crónica, así como con complicaciones y eventos renales, cardiacos y cerebrales. En conclusión, en individuos con riesgo de desarrollar enfermedad renal crónica, o en quienes ya la padecen, la medición de la rigidez arterial y de los daños ateroscleróticos de la pared vascular serían parámetros centrales para su evaluación y uno de los objetivos a considerar al diseñar estrategias preventivas del deterioro de los órganos blanco y eventos.

Abstract There exist significant structural changes in the artery wall in almost all clinical stages of chronic kidney disease. They constitute a prognostic marker and, at the same time, a progression factor and an event factor, both cardiovascular and renal. For that reason, it is essential to have an estimation of vascular damage and, even better, an accurate diagnosis. Vascular evaluation during clinical consultation by means of determining pulse pressure and ankle-brachial pressure index are a helpful initial orientation of these patient´s artery damage. Today we can assess, in an accessible way, the structural lesions of the arteries by means of quantification and characterization, through vascular ultrasound, of carotid and femoral atherosclerotic plaques and through the pulse wave velocity. The vast majority of renal patients show increased pulse wave velocity, compared to healthy populations, as a result of multiple pathogenic mechanisms. Vascular alterations, both of large arteries and at the microcirculation level, are strongly linked to the progression of chronic kidney disease, as well as renal, cardiac and cerebral complications and events. In individuals at risk of developing chronic kidney disease, or in those who already suffer from it, the measurement of arterial stiffness and of atherosclerotic damage to the vascular wall is a central parameter for evaluation and one of the objectives to consider when designing preventive strategies against deterioration of target organs and events.

Multitarget deep brain stimulation for clinically complex movement disorders.

Deep brain stimulation (DBS) of single-target nuclei has produced remarkable functional outcomes in a number of movement disorders such as Parkinson's disease, essential tremor, and dystonia. While these benefits are well established, DBS efficacy and strategy for unusual, unclassified movement disorder syndromes is less clear. A strategy of dual pallidal and thalamic electrode placement is a rational approach in such cases where there is profound, medically refractory functional impairment. The authors report a series of such cases: midbrain cavernoma hemorrhage with olivary hypertrophy, spinocerebellar ataxia-like disorder of probable genetic origin, Holmes tremor secondary to brainstem stroke, and hemiballismus due to traumatic thalamic hemorrhage, all treated by dual pallidal and thalamic DBS. All patients demonstrated robust benefit from DBS, maintained in long-term follow-up. This series demonstrates the flexibility and efficacy, but also the limitations, of dual thalamo-pallidal stimulation for managing axial and limb symptoms of tremors, dystonia, chorea, and hemiballismus in patients with complex movement disorders.

Babo1, formerly Vop1 and Cop1/2, is no eyespot photoreceptor but a basal body protein illuminating cell division in Volvox carteri.

In photosynthetic organisms many processes are light dependent and sensing of light requires light-sensitive proteins. The supposed eyespot photoreceptor protein Babo1 (formerly Vop1) has previously been classified as an opsin due to the capacity for binding retinal. Here, we analyze Babo1 and provide evidence that it is no opsin. Due to the localization at the basal bodies, the former Vop1 and Cop1/2 proteins were renamed V.c. Babo1 and C.r. Babo1. We reveal a large family of more than 60 Babo1-related proteins from a wide range of species. The detailed subcellular localization of fluorescence-tagged Babo1 shows that it accumulates at the basal apparatus. More precisely, it is located predominantly at the basal bodies and to a lesser extent at the four strands of rootlet microtubules. We trace Babo1 during basal body separation and cell division. Dynamic structural rearrangements of Babo1 particularly occur right before the first cell division. In four-celled embryos Babo1 was exclusively found at the oldest basal bodies of the embryo and on the corresponding d-roots. The unequal distribution of Babo1 in four-celled embryos could be an integral part of a geometrical system in early embryogenesis, which establishes the anterior-posterior polarity and influences the spatial arrangement of all embryonic structures and characteristics. Due to its retinal-binding capacity, Babo1 could also be responsible for the unequal distribution of retinoids, knowing that such concentration gradients of retinoids can be essential for the correct patterning during embryogenesis of more complex organisms. Thus, our findings push the Babo1 research in another direction.

Tractography-based targeting of the ventral intermediate nucleus: accuracy and clinical utility in MRgFUS thalamotomy.

OBJECTIVE: Tractography-based targeting of the thalamic ventral intermediate nucleus (T-VIM) is a novel method conferring patient-specific selection of VIM coordinates for tremor surgery; however, its accuracy and clinical utility in magnetic resonance imaging-guided focused ultrasound (MRgFUS) thalamotomy compared to conventional indirect targeting has not been specifically addressed. This retrospective study sought to compare the treatment locations and potential adverse effect profiles of T-VIM with indirect targeting in a large cohort of MRgFUS thalamotomy patients. METHODS: T-VIM was performed using diffusion tractography outlining the pyramidal and medial lemniscus tracts in 43 MRgFUS thalamotomy patients. T-VIM coordinates were compared with the indirect treatment coordinates used in the procedure. Thalamotomy lesions were delineated on postoperative T1-weighted images and displaced ("translated") by the anteroposterior and mediolateral difference between T-VIM and treatment coordinates. Both translated and actual lesions were normalized to standard space and subsequently overlaid with areas previously reported to be associated with an increased risk of motor and sensory adverse effects when lesioned during MRgFUS thalamotomy. RESULTS: T-VIM coordinates were 2.18 mm anterior and 1.82 mm medial to the "final" indirect treatment coordinates. Translated lesions lay more squarely within the boundaries of the VIM compared to nontranslated lesions and showed significantly less overlap with areas associated with sensory adverse effects. Translated lesions overlapped less with areas associated with motor adverse effects; however, this difference was not significant. CONCLUSIONS: T-VIM leads to the selection of more anterior and medial coordinates than the conventional indirect methods. Lesions moved toward these anteromedial coordinates avoid areas associated with an increased risk of motor and sensory adverse effects, suggesting that T-VIM may improve clinical outcomes.

Deep brain stimulation of the ventroanterior and ventrolateral thalamus improves motor function in a rat model of Parkinson's disease.

Parkinson's disease (PD) is a neurodegenerative disease with affected individuals exhibiting motor symptoms of bradykinesia, muscle rigidity, tremor, postural instability and gait dysfunction. The current gold standard treatment is pharmacotherapy with levodopa, but long-term use is associated with motor response fluctuations and can cause abnormal movements called dyskinesias. An alternative treatment option is deep brain stimulation (DBS) with the two FDA-approved brain targets for PD situated in the basal ganglia; specifically, in the subthalamic nucleus (STN) and globus pallidus pars interna (GPi). Both improve quality of life and motor scores by ~50-70% in well-selected patients but can also elicit adverse effects on cognition and other non-motor symptoms. Therefore, identifying a novel DBS target that is efficacious for patients not optimally responsive to current DBS targets with fewer side-effects has clear clinical merit. Here, we investigate whether the ventroanterior (VA) and ventrolateral (VL) motor nuclei of the thalamus can serve as novel and effective DBS targets for PD. In the limb-use asymmetry test (LAT), hemiparkinsonian rats showcased left forelimb akinesia and touched only 6.5 ±â€¯1.3% with that paw. However, these animals touched equally with both forepaws with DBS at 10 Hz, 100 µsec pulse width and 100 uA cathodic stimulation in the VA (n = 7), VL (n = 8) or at the interface between the two thalamic nuclei which we refer to as the VA|VL (n = 12). With whole-cell patch-clamp recordings, we noted that VA|VL stimulation in vitro increased the number of induced action potentials in proximal neurons in both areas albeit VL neurons transitioned from bursting to non-bursting action potentials (APs) with large excitatory postsynaptic potentials time-locked to stimulation. In contrast, VA neurons were excited with VA|VL electrical stimulation but with little change in spiking phenotype. Overall, our findings show that DBS in the VA, VL or VA|VL improved motor function in a rat model of PD; plausibly via increased excitation of residing neurons.

Measurement of peripheral blood flow in patients with peripheral artery disease: Methods and considerations.

Peripheral artery disease (PAD) is a manifestation of generalized atherosclerosis which results in hemodynamic compromise of oxygen and substrate delivery to the lower extremity skeletal muscles. Hemodynamic assessments are vital in PAD diagnosis and in the evaluation of strategies aimed at treating claudication (i.e. exercise training, revascularization, and pharmacological agents). Venous occlusion plethysmography (VOP) is a century-old, non-invasive technique used to quantify limb blood flow and has been used to evaluate hemodynamic compromise in patients with PAD. However, the literature suggests a wide array of methodological variability in the measurement and analysis of limb blood flow using VOP. In this manuscript, we overview the clinical application of VOP measurement, and secondly we review the methodological variation that occurs during the measurement and analysis of VOP in healthy individuals and in patients with claudication.

Gamma oscillations in the somatosensory thalamus of a patient with a phantom limb: case report.

The amputation of an extremity is commonly followed by phantom sensations that are perceived to originate from the missing limb. The mechanism underlying the generation of these sensations is still not clear although the development of abnormal oscillatory bursting in thalamic neurons may be involved. The theory of thalamocortical dysrhythmia implicates gamma oscillations in phantom pathophysiology although this rhythm has not been previously observed in the phantom limb thalamus. In this study, the authors report the novel observation of widespread 38-Hz gamma oscillatory activity in spike and local field potential recordings obtained from the ventral caudal somatosensory nucleus of the thalamus (Vc) of a phantom limb patient undergoing deep brain stimulation (DBS) surgery. Interestingly, microstimulation near tonically firing cells in the Vc resulted in high-frequency, gamma oscillatory discharges coincident with phantom sensations reported by the patient. Recordings from the somatosensory thalamus of comparator groups (essential tremor and pain) did not reveal the presence of gamma oscillatory activity.

Unilateral thalamic and pallidal deep brain stimulation for idiopathic hemidystonia: results of individual and combined stimulations. Case report.

Pallidal stimulation has been the usual surgical treatment for dystonia in the last decades. The continuous investigation of the physiopathology and the motor pathways involved leads to the search for complementary targets to improve results. The authors present the case of a 37-year-old woman who had suffered from idiopathic hemidystonia with hyperkinetic and hypokinetic movements for 11 years, and who was treated with deep brain stimulation. A brief literature review is also provided. The globus pallidus internus and the ventral intermediate/ventral oral posterior complex of the thalamus were stimulated separately and simultaneously for 3 months and compared using the Burke-Fahn-Marsden Dystonia Rating Scale and the Global Dystonia Severity Rating Scale, with a 3.5-year follow-up. The synergism of multiple-target stimulation resulted in a complete improvement of the mixed dystonic symptoms.

Post-Traumatic Tremor and Thalamic Deep Brain Stimulation: Evidence for Use of Diffusion Tensor Imaging.

BACKGROUND: Deep brain stimulation (DBS) is a well-established treatment to reduce tremor, notably in Parkinson disease. DBS may also be effective in post-traumatic tremor, one of the most common movement disorders caused by head injury. However, the cohorts of patients often have multiple lesions that may impact the outcome depending on which fiber tracts are affected. CASE DESCRIPTION: A 20-year-old man presented after road traffic accident with severe closed head injury and polytrauma. Computed tomography scan showed left frontal and basal ganglia hemorrhagic contusions and intraventricular hemorrhage. A disabling tremor evolved in step with motor recovery. Despite high-intensity signals in the intended thalamic target, a visual analysis of the preoperative diffusion tensor imaging revealed preservation of connectivity of the intended target, ventralis oralis posterior thalamic nucleus (VOP). This was confirmed by the postoperative tractography study presented here. DBS of the VOP/zona incerta was performed. Six months postimplant, marked improvement of action (postural, kinetic, and intention) tremor was achieved. CONCLUSIONS: We demonstrated a strong connectivity between the VOP and the superior frontal gyrus containing the premotor cortex and other central brain areas responsible for movement control. In spite of an existing lesion in the target, the preservation of these tracts may be relevant to the improvement of the patient's symptoms by DBS.

Impact of a Meditation Program on Pulse-Wave Velocity, C-reactive Protein and Quality of life / Impacto de un programa de meditación sobre la velocidad de onda de pulso, la proteína C-reactiva y la calidad de vida

background: Although various studies refer to the effect of meditation on blood pressure (BP), its impact on other cardiovascular clinical variables is unknown. Objective: The aim of this study was to evaluate the effects of a meditation program on pulse wave velocity (PWV), quality of life and ultrasensitive C-reactive protein (us-CRP) in patients with ischemic heart disease or chronic heart failure. Methods: This was a randomized study with two groups of patients: a meditation group (M) and an active control group (AC) with cardiovascular health education, evaluating the difference between initial and final values at 12 weeks of B P, PWV, quality of life (assessed by the SF-36 questionnaire) and us-CRP. results: Thirty-five patients were included in the M group and 35 in the AC group; mean age was 61 years and 80% were men. Both groups had similar baseline characteristics, except for higher number of smokers and triglyceride levels in the M group. At 12 weeks, no significant differences were found for ∆PWV: +0.51 (±1.40) in AC and +0.19 (±1.53) in M (p=0.37). Conversely, ∆SF-36 was +0.79 (±7.58) in AC vs. +5.40 (±9.69) (p=0.03) in M, and ∆us-PCR was +1.17 (±2.9) in AC vs. -0.69 (±0.89) in M (p=0.02). Conclusions: A meditation program did not significantly modify PWV at 12 weeks. However, patients allocated to this intervention improved their quality of life and us-PCR was significantly reduced. Larger studies are required to confirm these findings and explore the mechanisms involved in this improvement.

Pallidal stimulation for Holmes tremor: clinical outcomes and single-unit recordings in 4 cases.

OBJECT: Holmes tremor (HT) is characterized by irregular, low-frequency (< 4.5 Hz) tremor occurring at rest, with posture, and with certain actions, often affecting proximal muscles. Previous reports have tended to highlight the use of thalamic deep brain stimulation (DBS) in cases of medication-refractory HT. In this study, the authors report the clinical outcome and analysis of single-unit recordings in patients with medication-refractory HT treated with globus pallidus internus (GPi) DBS. METHODS: The authors retrospectively reviewed the medical charts of 4 patients treated with pallidal DBS for medication-refractory HT at the University of California, San Francisco, and San Francisco Veterans Affairs Medical Center. Clinical outcomes were measured at baseline and after surgery using an abbreviated motor-severity Fahn-Tolosa-Marin (FTM) tremor rating scale. Intraoperative microelectrode recordings were performed with patients in the awake state. The neurophysiological characteristics identified in HT were then also compared with characteristics previously described in Parkinson's disease (PD) studied at the authors' institution. RESULTS: The mean percentage improvement in tremor motor severity was 78.87% (range 59.9%-94.4%) as measured using the FTM tremor rating scale, with an average length of follow-up of 33.75 months (range 18-52 months). Twenty-eight GPi neurons were recorded intraoperatively in the resting state and 13 of these were also recorded during contralateral voluntary arm movement. The mean firing rate at rest in HT was 56.2 ± 28.5 Hz, and 63.5 ± 19.4 Hz with action, much lower than the GPi recordings in PD. GPi unit oscillations of 2-8 Hz were prominent in both patients with HT and those with PD, but in HT, unlike PD, these oscillations were not suppressed by voluntary movement. CONCLUSIONS: The efficacy of GPi DBS exceeded that reported in prior studies of ventrolateral thalamus DBS and suggest GPi may be a better target for treating HT. These clinical and neurophysiological findings help illuminate evolving models of HT and highlight the importance of cerebellar-basal ganglia interactions.