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Introduction: Directional deep brain stimulation (DBS) leads have become widely used in the past decade. Understanding the asymmetric stimulation provided by directional leads requires precise knowledge of the exact orientation of the lead in respect to its anatomical target. Recently, the DiODe algorithm was developed to automatically determine the orientation angle of leads from the artifact on postoperative computed tomography (CT) images. However, manual DiODe results are user-dependent. This study analyzed the extent of lead rotation as well as the user agreement of DiODe calculations across the two most common DBS systems, namely, Boston Scientific's Vercise and Abbott's Infinity, and two independent medical institutions. Methods: Data from 104 patients who underwent an anterior-facing unilateral/bilateral directional DBS implantation at either Northwestern Memorial Hospital (NMH) or Albany Medical Center (AMC) were retrospectively analyzed. Actual orientations of the implanted leads were independently calculated by three individual users using the DiODe algorithm in Lead-DBS and patients' postoperative CT images. The deviation from the intended orientation and user agreement were assessed. Results: All leads significantly deviated from the intended 0° orientation (p < 0.001), regardless of DBS lead design (p < 0.05) or institution (p < 0.05). However, the Boston Scientific leads showed an implantation bias toward the left at both institutions (p = 0.014 at NMH, p = 0.029 at AMC). A difference of 10° between at least two users occurred in 28% (NMH) and 39% (AMC) of all Boston Scientific and 76% (NMH) and 53% (AMC) of all Abbott leads. Conclusion: Our results show that there is a significant lead rotation from the intended surgical orientation across both DBS systems and both medical institutions; however, a bias toward a single direction was only seen in the Boston Scientific leads. Additionally, these results raise questions into the user error that occurs when manually refining the orientation angles calculated with DiODe. [ABSTRACT FROM AUTHOR]

Introduction: Deep brain stimulation (DBS) is a common treatment for a variety of neurological and psychiatric disorders. Recent studies have highlighted the role of neuroimaging in localizing the position of electrode contacts relative to target brain areas in order to optimize DBS programming. Among different imaging methods, postoperative magnetic resonance imaging (MRI) has been widely used for DBS electrode localization; however, the geometrical distortion induced by the lead limits its accuracy. In this work, we investigated to what degree the difference between the actual location of the lead's tip and the location of the tip estimated from the MRI artifact varies depending on the MRI sequence parameters such as acquisition plane and phase encoding direction, as well as the lead's extracranial configuration. Accordingly, an imaging technique to increase the accuracy of lead localization was devised and discussed. Methods: We designed and constructed an anthropomorphic phantom with an implanted DBS system following 18 clinically relevant configurations. The phantom was scanned at a Siemens 1.5 Tesla Aera scanner using a T1MPRAGE sequence optimized for clinical use and a T1TSE sequence optimized for research purposes. We varied slice acquisition plane and phase encoding direction and calculated the distance between the caudal tip of the DBS lead MRI artifact and the actual tip of the lead, as estimated from MRI reference markers. Results: Imaging parameters and lead configuration substantially altered the difference in the depth of the lead within its MRI artifact on the scale of several millimeters − with a difference as large as 4.99 mm. The actual tip of the DBS lead was found to be consistently more rostral than the tip estimated from the MR image artifact. The smallest difference between the tip of the DBS lead and the tip of the MRI artifact using the clinically relevant sequence (i.e., T1MPRAGE) was found with the sagittal acquisition plane and anterior-posterior phase encoding direction. Discussion/Conclusion: The actual tip of an implanted DBS lead is located up to several millimeters rostral to the tip of the lead's artifact on postoperative MR images. This distance depends on the MRI sequence parameters and the DBS system's extracranial trajectory. MRI parameters may be altered to improve this localization. [ABSTRACT FROM AUTHOR]

Ultra-high field MRI at 7 T can produce much better visualization of sub-cortical structures compared to lower field, which can greatly help target verification as well as overall treatment monitoring for patients with deep brain stimulation (DBS) implants. However, use of 7 T MRI for such patients is currently contra-indicated by guidelines from the device manufacturers due to the safety issues. The aim of this study was to provide an assessment of safety and image quality of ultra-high field magnetic resonance imaging at 7 T in patients with deep brain stimulation implants. We performed experiments with both lead-only and complete DBS systems implanted in anthropomorphic phantoms. RF heating was measured for 43 unique patient-derived device configurations. Magnetic force measurements were performed according to ASTM F2052 test method, and device integrity was assessed before and after experiments. Finally, we assessed electrode artifact in a cadaveric brain implanted with an isolated DBS lead. RF heating remained below 2°C, similar to a fever, with the 95% confidence interval between 0.38°C-0.52°C. Magnetic forces were well below forces imposed by gravity, and thus not a source of concern. No device malfunctioning was observed due to interference from MRI fields. Electrode artifact was most noticeable on MPRAGE and T2*GRE sequences, while it was minimized on T2-TSE images. Our work provides the safety assessment of ultra-high field MRI at 7 T in patients with DBS implants. Our results suggest that 7 T MRI may be performed safely in patients with DBS implants for specific implant models and MRI hardware. [ABSTRACT FROM AUTHOR]

Background: Patients with deep brain stimulation (DBS) implants have limited access to MRI due to safety concerns associated with RF‐induced heating. Currently, MRI in these patients is allowed in 1.5T horizontal bore scanners utilizing pulse sequences with reduced power. However, the use of 3T MRI in such patients is increasingly reported based on limited safety assessments. Here we present the results of comprehensive RF heating measurements for two commercially available DBS systems during MRI at 1.5T and 3T. Purpose To assess the effect of imaging landmark, DBS lead configuration, and patient's body composition on RF heating of DBS leads during MRI at 1.5T and 3T. Study Type: Phantom and ex vivo study. Population/Subjects/Phantom/Specimen/Animal Model: Gel phantoms and cadaver brain. Field Strength/Sequence: 1.5T and 3T, T1‐weighted turbo spin echo. Assessment RF heating was measured at the tips of DBS leads implanted in brain‐mimicking gel. Image artifact was assessed in a cadaver brain implanted with an isolated DBS lead. Statistical Tests: Descriptive. Results: We observed substantial fluctuation in RF heating, mainly affected by phantom composition and DBS lead configuration, ranging from 0.14°C to 23.73°C at 1.5T, and from 0.10°C to 7.39°C at 3T. The presence of subcutaneous fat substantially altered RF heating at the electrode tips (3.06°C < ∆T < 19.05° C). Introducing concentric loops in the extracranial portion of the lead at the surgical burr hole reduced RF heating by up to 89% at 1.5T and up to 98% at 3T compared to worst‐case heating scenarios. Data Conclusion: Device configuration and patient's body composition substantially altered the RF heating of DBS leads during MRI. Interestingly, certain lead trajectories consistently reduced RF heating and image artifact. Level of Evidence 1 Technical Efficacy Stage 1 J. MAGN. RESON. IMAGING 2021;53:599–610. [ABSTRACT FROM AUTHOR]

Patients with deep brain stimulation (DBS) implants can significantly benefit from magnetic resonance imaging (MRI), however access to MRI is restricted in these patients because of safety concerns due to RF heating of the leads. Recently we introduced a patient-adjustable reconfigurable transmit coil for low-SAR imaging of DBS at 1.5T. A previous simulation study demonstrated a substantial reduction in the local SAR around single DBS leads in 9 unilateral lead models. This work reports the first experimental results of temperature measurement at the tips of bilateral DBS leads with realistic trajectories extracted from postoperative CT images of 10 patients (20 leads in total). A total of 200 measurements were performed to record temperature rise at the tips of the leads during 2 minutes of scanning with the coil rotated to cover all accessible rotation angles. In all patients, we were able to find an optimum coil rotation angle and reduced the heating of both left and right leads to a level below the heating produced by the body coil. An average heat reduction of 65% was achieved for bilateral leads. When considering each lead alone, an average heat reduction of 80% was achieved. Our results suggest that reconfigurable coil technology introduces a promising approach for imaging of patients with DBS implants. [ABSTRACT FROM AUTHOR]

Introduction: Decremental responses in repetitive nerve stimulation have been reported in a few hereditary myopathies. We examined the frequency of decrement in a cohort of myopathy patients.Methods: We reviewed all patients referred for myopathy who underwent repetitive nerve stimulation between January 2007 and May 2017. We included patients with decrement (>10%) and either a pathological or molecular diagnosis of myopathy.Results: Among 157 patients with myopathies, 4 patients had decrement (2 hydroxychloroquine-associated vacuolar myopathy, 1 centronuclear myopathy, and 1 distal myopathy). One hydroxychloroquine-associated vacuolar myopathy patient also had inflammatory myopathy. Pyridostigmine improved weakness in the centronuclear myopathy patient, but not in the distal myopathy patient. No patient with an acquired myopathy received pyridostigmine.Conclusions: Despite the rare occurrence of decrement in myopathy, its presence may urge consideration of pharmacological intervention. Muscle Nerve 59:475-478, 2019. [ABSTRACT FROM AUTHOR]

The rubber hand illusion (RHI) paradigm experimentally produces an illusion of rubber hand ownership and arm shift by simultaneously stroking a rubber hand in view and a participant's visually occluded hand. It involves visual, tactile, and proprioceptive multisensory integration and activates multisensory areas in the brain, including the posterior parietal cortex (PPC). Multisensory inputs are transformed into outputs for motor control in association areas such as PPC. A behavioral study reported decreased motor performance after RHI. However, it remains unclear whether RHI modifies the interactions between sensory and motor systems and between PPC and the primary motor cortex (M1). We used transcranial magnetic stimulation (TMS) and examined the functional connections from the primary somatosensory and association cortices to M1 and from PPC to M1 during RHI. In experiment 1, short-latency afferent inhibition (SAI) and long-latency afferent inhibition (LAI) were measured before and immediately after a synchronous (RHI) or an asynchronous (control) condition. In experiment 2, PPC-M1 interaction was measured using two coils. We found that SAI and LAI were reduced in the synchronous condition compared with baseline, suggesting that RHI decreased somatosensory processing in the primary sensory and the association cortices projecting to M1. We also found that greater inhibitory PPC-M1 interaction was associated with stronger RHI assessed by questionnaire. Our findings suggest that RHI modulates both the early and late stages of processing of tactile afferent, which leads to altered M1 excitability by reducing the gain of somatosensory afferents to resolve conflicts among multisensory inputs. [ABSTRACT FROM AUTHOR]

Emergency medicine is a relatively new specialty in Iran. Therefore, the general public and the medical community do not have enough information on its duties, capabilities, its nature, and its work schedule or its degree of occupational difficulty compared to other specialties. Hence, an insight from the early group of residents who selected this specialty can help identify the strengths and weaknesses of this field in order to promote the scientific quality of this field, and attract medical students. It can also help to alleviate deficiencies and strengthen positive aspects of emergency medicine. The aim of this study was to identify the reasons behind choosing emergency medicine as a specialty. A qualitative study was conducted using semi-structured interviews. Maximum variation opportunistic sampling was done, and face-to-face interviews were held with 23 emergency medicine residents and fellows (4 faculty members and 19 residents). Data were analyzed through thematic analysis, and categories and themes were extracted. The main levels extracted were: 1) Individual priorities, 2) the nature of work and the field of study, and 3) professional future. The themes of each main level were extracted and encoded. This study showed that the majority of residents choose emergency medicine specialty to achieve a better social and professional status in one of the most challenging fields of medicine. [ABSTRACT FROM AUTHOR]

Associative plasticity is hypothesized to be an important neurophysiological correlate of memory formation and learning with potentials for applications in neurorehabilitation and for the development of new electrophysiological measures to study disorders of cortical plasticity. We hypothesized that the magnitude of the paired associative stimulation (PAS)-induced long-term potentiation (LTP)-like effect depends on the number of pairs in the PAS protocol. We also hypothesized that homeostatic interaction of PAS with subsequent motor learning is related to the magnitude of the PAS-induced LTP-like effect. We studied 10 healthy subjects. In experiment 1a, subjects received 90 (PAS90), 180 (PAS180), or 270 (PAS270) pairs of stimuli, followed by a dynamic motor practice (DMP) 1 h after the end of the PAS protocols. In experiment 1b, the DMP preceded the PAS protocol. In experiment 2, the time course of PAS270 was studied. We found that PAS270 resulted in greater increase in motor evoked potential (MEP) amplitude compared with protocols with fewer pairs of stimuli. Moreover, the interaction between PAS protocols with motor learning differed depending on the number of stimulus pairs used to induce PAS. While DMP alone increased MEP amplitudes, DMP during the LTP-like effects induced by PAS270 led to a long-term depression (LTD)-like effect (homeostatic interaction). This homeostatic interaction did not occur after PAS90 and PAS180. In conclusion, we found a dose-dependent effect of the number of stimulus pairs used in the PAS protocol on cortical plasticity. Homeostatic interaction between PAS and DMP was observed only after PAS270. [ABSTRACT FROM AUTHOR]

This paper provides a theoretical assessment of the safety considerations encountered in the simultaneous use of transcranial magnetic stimulation (TMS) and neurological interventions involving implanted metallic electrodes, such as electrocorticography. Metal implants are subject to magnetic forces due to fast alternating magnetic fields produced by the TMS coil. The question of whether the mechanical movement of the implants leads to irreversible damage of brain tissue is addressed by an electromagnetic simulation which quantifies the magnitude of imposed magnetic forces. The assessment is followed by a careful mechanical analysis determining the maximum tolerable force which does not cause irreversible tissue damage. Results of this investigation provide useful information on the range of TMS stimulator output powers which can be safely used in patients having metallic implants. It is shown that conventional TMS applications can be considered safe when applied on patients with typical electrode implants as the induced stress in the brain tissue remains well below the limit of tissue damage. [ABSTRACT FROM AUTHOR]

Paired associative stimulation (PAS) of the motor cortex leads to increased motor evoked potential (MEP) amplitudes in the stimulated hand muscles. We hypothesized that evoking GABAA receptor-mediated short-interval intracortical inhibition (SICI) simultaneously with excitatory PAS would depress long-term potentiation plasticity in motor cortex. Four different PAS paradigms were tested, standard PAS (PAS25) and three conditioned PAS protocols (CS2-PAS25, CS2-PAS25adj, and CS10-PAS25adj). A subthreshold conditioning stimulus 2 ms (CS2) or 10 ms (CS10) before the test stimuli was added to the conditioned PAS protocols. Since CS2 has inhibitory and CS10 has facilitatory effect on cortical excitability, in the CS2-PAS25adj and CS10-PAS25adj protocols, TS intensity was adjusted to produce a 1-mV MEP in the presence of CS2 or CS10 to control for the degree of corticospinal excitation. As expected, MEP amplitudes after PAS25 were higher compared with that at baseline, but importantly, MEP amplitudes did not change after PAS was induced in the presence of SICI in either the CS2-PAS25 or CS2- PAS25adj condition. Furthermore, the CS10-PAS25adj protocol showed significantly increased MEP amplitude at 60 min after PAS compared with baseline. These results show that SICI blocked the induction of long-term potentiation-like plasticity in the motor cortex, indicating that GABAergic circuits play an important role in the regulation of cortical plasticity. The study demonstrates a noninvasive and nonpharmacological way to achieve focal modulation of plasticity. [ABSTRACT FROM AUTHOR]

The aim of the study was to evaluate and collect current evidence on the effect of antibiotics in pretreatment of pouchitis after restorative ileal pouch anal anastomosis (IPAA). Pubmed, Embase, Web of Science, Scopus, and Cochrane Library databases were searched between 1966 and July 2008; and relevant clinical trials extracted, reviewed, and validated according to the study protocol. The outcome of interest was clinical improvement after treatment. Nine randomized, placebo-controlled clinical trials were found relevant and studied but 3 of them with 70 patients were entered into meta-analysis. Pooling of the results from these trials yielded an odds ratio of 15.96 with a 95% CI of 4.20–60.70, indicating a significant OR (p<0.0001) in treatment group in comparison to the placebo group. In conclusion, the meta-analysis confirms benefit of antibiotics in management of pouchitis after IPAA operation. [ABSTRACT FROM AUTHOR]

Deep brain stimulation (DBS) offers therapeutic benefits to patients suffering from a variety of treatment-resistant neurological and psychiatric disorders. The newest generation of DBS devices now offer directional leads, which utilize segmented electrodes to direct current asymmetrically to the neuronal tissue. Since segmented electrodes offer a larger degree of freedom for contact positioning, it is critical to assess how well the surgically intended and the actual orientation of the lead match to facilitate programming and allow appropriate interpretation of the therapeutic outcome. Postoperative image analysis algorithms, such as DiODe, are commonly used to determine DBS leads' actual orientation. In this work, we used DiODe to compare the deviation between intended and actual orientations of DBS leads across two most commonly implanted directional DBS systems, namely, Boston Scientific Cartesia™ and St. Jude Medical Infinity. This study is the first to investigate the rotation of leads from both DBS systems in a large group of 86 patients. Clinical Relevance- Our results quantify the variability between the surgically intended and actual orientations of Boston Scientific Vercise and St. Jude Medical Infinity DBS systems thus highlighting the need to develop more precise implantation procedures.

Deep brain stimulation (DBS) is an established yet growing treatment for a range of neurological and psychiatric disorders. Over the last decade, numerous studies have underscored the effect of electrode placement on the clinical outcome of DBS. As a result, imaging is now extensively used for DBS electrode localization, even though the accuracy of different modalities in determining the true coordinates of DBS electrodes is less explored. Postoperative magnetic resonance imaging (MRI) is a gold standard method for DBS electrode localization, however, the geometrical distortion induced by the lead's artifact could limit the accuracy. In this work, we investigated to what degree the difference between the true location of the lead's tip and the location of the tip estimated from the MRI artifact varies depending on the MRI sequence parameters, acquisition plane, phase encoding direction, and the implant"s extracranial trajectory. Clinical Relevance- Results will help researchers and clinicians to estimate the true location of DBS leads and contacts from postoperative MRI scans.

Deep brain stimulation (DBS) promises to treat an increasing number of neurological and psychiatric disorders. DBS outcome is directly a factor of optimal targeting of the relevant brain structures. Computational models can help to interpret a patient's outcome by predicting the volume of tissue activated (VTA) around DBS electrode contacts. Here we report results of a preliminary study of DBS in two patients with obsessive-compulsive disorder and show that VTA predictions, which are based on patient-specific volume conductor models, correlate with clinical outcome. Our results suggest that patient specific VTA calculation can help inform device programing to maximize therapeutic effects and minimize side effects.Clinical Relevance- Patient-specific modeling of the volume of activated tissue can predict clinical outcomes and thus, can help to optimize DBS device programing to maximize therapeutic effects.

Deep brain stimulation (DBS) has evolved to an important treatment for several drug-resistant neurological and psychiatric disorders, such as epilepsy, Parkinson's disease, essential tremor and dystonia. Despite general effectiveness of DBS, however, its mechanisms of action are not completely understood. Simulations are commonly used to predict the volume of tissue activated (VTA) around DBS electrodes, which in turn helps interpreting clinical outcomes and understand therapeutic mechanisms. Computational models are commonly used to visualize the extend of volume of activated tissue (VTA) for different stimulation schemes, which in turn helps interpreting and understanding the outcomes. The degree of model complexity, however, can affect the predicted VTA. In this work we investigate the effect of volume conductor model complexity on the predicted VTA, when the VTA is estimated from activation function field metrics. Our results can help clinicians to decide what level of model complexity is suitable for their specific need.

Patients with deep brain stimulation (DBS) implants are often denied access to magnetic resonance imaging (MRI) due to safety concerns associated with RF heating of implants. Although MR-conditional DBS devices are available, complying with manufacturer guidelines has proved to be difficult as pulse sequences that optimally visualize DBS target structures tend to have much higher specific absorption rate (SAR) of radiofrequency energy than current guidelines allow. The MR-labeling of DBS devices, as well as the majority of studies on RF heating of conductive implants have been limited to horizontal close-bore MRI scanners. Vertical MRI scanners, originally introduced as open low-field MRI systems, are now available at 1.2 T field strength, capable of high-resolution structural and functional imaging. No literature exists on DBS SAR in this class of scanners which have a 90° rotated transmit coil and thus, generate a fundamentally different electric and magnetic field distributions. Here we present a simulation study of RF heating in a cohort of forty patient-derived DBS lead models during MRI in a commercially available vertical openbore MRI system (1.2 T OASIS, Hitachi) and a standard horizontal 1.5 T birdcage coil. Simulations were performed at two major imaging landmarks representing head and chest imaging. We calculated the maximum of 0.1g-averaged SAR (0.1g-SAR Max ) around DBS lead tips when a B 1 + = 4 µT was generated on an axial plane passing through patients body. For head landmark, 0.1g-SAR Max reached 220±188 W/kg in the 1.5 T birdcage coil, but only 14±11 W/kg in the OASIS coil. For chest landmark, 0.1g-SAR Max was 24±17 W/kg in the 1.5 T birdcage coil and 3±2 W/kg in the OASIS coil. A paired two-tail t-test revealed a significant reduction in SAR with a large effect-size during head MRI (p < 1.5×10 -8 , Cohen's d = 1.5) as well as chest MRI (p < 6.5×10 -10 , Cohen's d = 1.7) in 1.2 T Hitachi OASIS coil compared to a standard 1.5 T birdcage transmitter. Our findings suggest that open-bore vertical scanners may offer an untapped opportunity for MRI of patients with DBS implants.

Patients with deep brain stimulation (DBS) devices have limited access to magnetic resonance imaging (MRI) due to safety concerns associated with RF heating generated around the implant. The problem of predicting RF heating of conductive leads is complex with a large parameter space and several interplaying factors. Recently however, off-label use of MRI in patients with DBS devices has been reported based on limited safety assessments, raising the concern that potentially dangerous scenarios may have been overlooked. In this work, we present results of a systematic assessment of RF heating of a commercial DBS device during MRI at 1.5T and 3T, taking into account the effect of device configuration, imaging landmark, and patient's body composition. Ninety-six (96) RF heating measurements were performed using anthropomorphic phantoms implanted with a full DBS system. We evaluated eight clinically relevant device configurations, implanted in phantoms with different material compositions, and imaged at three different landmarks (head, shoulder, and lower chest) in 1.5 T and 3T scanners. We observed a substantial fluctuation in the RF heating depending on phantom's composition and device configuration. RF heating in the brain-mimicking gel varied from 0.1°C to 12°C during 1.5 T MRI and from <0.1°C to 4.5°C during 3T MRI. We also observed that certain device configurations consistently reduced RF heating across different phantom compositions, imaging landmarks, and MRI transmit frequencies.

Background: Pedunculopontine nucleus (PPN) has complex reciprocal connections with basal ganglia, especially with internal globus pallidus and substantia nigra, and it has been postulated that PPN stimulation may improve gait instability and freezing of gait. In this meta-analysis, we will assess the evidence for PPN deep brain stimulation in treatment of gait and motor abnormalities especially focusing on Parkinson disease patients., Methods: PubMed and Scopus electronic databases were searched for related studies published before February 2014. Medline (1966-2014), Embase (1974-2010), CINAHL, Web of Science, Scopus bibliographic, and Google Scholar databases (1960-2014) were also searched for studies investigating effect of PPN deep brain stimulation in treatment of postural and postural instability and total of ten studies met the inclusion criteria for this analysis., Results: Our findings showed a significant improvement in postural instability (p<0.001) and motor symptoms of Parkinson disease on and off medications (p<0.05), but failed to show improvement in freezing of gait., Conclusions: Despite significant improvement in postural instability observed in included studies, evidence from current literature is not sufficient to generalize these findings to the majority of patients.

Planar electrodes are increasingly used in therapeutic neural stimulation techniques such as functional electrical stimulation, epidural spinal cord stimulation (ESCS), and cortical stimulation. Recently, optimized electrode geometries have been shown to increase the efficiency of neural stimulation by increasing the variation of current density on the electrode surface. In the present work, a new family of modified fractal electrode geometries is developed to enhance the efficiency of neural stimulation. It is shown that a promising approach in increasing the neural activation function is to increase the "edginess" of the electrode surface, a concept that is explained and quantified by fractal mathematics. Rigorous finite element simulations were performed to compute electric potential produced by proposed modified fractal geometries. The activation of 256 model axons positioned around the electrodes was then quantified, showing that modified fractal geometries required a 22% less input power while maintaining the same level of neural activation. Preliminary in vivo experiments investigating muscle evoked potentials due to median nerve stimulation showed encouraging results, supporting the feasibility of increasing neural stimulation efficiency using modified fractal geometries.

Background: Levodopa-induced dyskinesias (LID) are amongst the most disabling side-effects of levodopa therapy for Parkinson's disease (PD). It has been suggested that that N-Methyl-D-Aspartate (NMDA)-receptor antagonist may reduce peak-dose dyskinesia in PD patients and may lead to motor improvement. In this study, we compared the efficacy of NMDA receptor antagonists versus placebo in the treatment of LID in PD through a meta-analysis of controlled trials., Methods: Electronic search of Pubmed (1990 - 2010), Medline (1966-2010), EMBASE (1974-2010) and other databases for relevant studies were performed. Controlled clinical trials of the effects of NMDA antagonists on LID that fulfill the study protocol were selected. Pooled data from included studies was then used to perform random and fixed effect models meta-analysis., Results: The search resulted in 11 randomized, placebo controlled clinical trials that involved a total of 253 PD patients with peak-dose LID. The outcome measures were various dyskinesia rating scales and the Unified Parkinson Disease Rating Scale (UPDRS) subscales III and IV. The analysis showed significant reduction in Standard Mean Difference (SMD) for UPDRS IV (SMD -1.45; 95%CI -2.28 to -0.63) and UPDRS III (SMD -0.41; 95%CI -0.69 to -0.12) after treatment with amantadine. Other included drugs did not show significant change in the outcomes measured., Conclusion: This meta-analysis provides an update on the clinical trials and confirms the short-term benefits of amantadine therapy in the treatment of dyskinesia. The effects of other NMDA receptor antagonists need to be evaluated further in clinical trials.

In this paper we studied the effects of external fields' polarization on the coupling of pure magnetic fields into human body. Finite Difference Time Domain (FDTD) method is used to calculate the current densities induced in a 1 cm resolution anatomically based model with proper tissue conductivities. Twenty different tissues have been considered in this investigation and scaled FDTD technique is used to convert the results of computer code run in 15 MHz to low frequencies which are encountered in the vicinity of industrial induction heating and melting devices. It has been found that external magnetic field's orientation due to human body has a pronounced impact on the level of induced currents in different body tissues. This may potentially help developing protecting strategies to mitigate the situations in which workers are exposed to high levels of external magnetic radiation.

In this case report we describe the first case of hemophagocytic lymphohistiocytosis with concurrent cutis marmorata telangiectatica congenita. She had pancytopenia and hepatosplenomegaly, hemophagocytic cells in spleen necropsy, and she died with respiratory failure and pseudomonas induced septicemia.