Management of Impulse Control and Related Disorders in Parkinson's Disease: An Expert Consensus.

BACKGROUND: Impulse-control and related behavioral disorders (ICBDs) significantly impact the lives of Parkinson's disease (PD) patients and caregivers, with lasting consequences if undiagnosed and untreated. While ICBD pathophysiology and risk factors are well-studied, a standardized severity definition and treatment evidence remain elusive. OBJECTIVE: This work aimed to establish international expert consensus on ICBD treatment strategies. To comprehensively address diverse treatment availabilities, experts from various continents were included. METHODS: From 2021 to 2023, global movement disorders specialists engaged in a Delphi process. A core expert group initiated surveys, involving a larger panel in three iterations, leading to refined severity definitions and treatment pathways. RESULTS: Experts achieved consensus on defining ICBD severity, emphasizing regular PD patient screenings for early detection. General treatment recommendations focused on continuous monitoring, collaboration with significant others, and seeking specialist advice for legal or financial challenges. For mild to severe ICBDs, gradual reduction in dopamine agonists was endorsed, followed by reductions in other PD medications. Second-line treatment strategies included diverse approaches like reversing the last medication change, cognitive behavior therapy, subthalamic nucleus deep brain stimulation, and specific medications like quetiapine, clozapine, and antidepressants. The panel reached consensus on distinct treatment pathways for punding and dopamine dysregulation syndrome, formulating therapy recommendations. Comprehensive discussions addressed management strategies for the exacerbation of either motor or non-motor symptoms following the proposed treatments. CONCLUSION: The consensus offers in-depth insights into ICBD management, presenting clear severity criteria and expert consensus treatment recommendations. The study highlights the critical need for further research to enhance ICBD management. © 2024 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Linking connectivity of deep brain stimulation of nucleus accumbens area with clinical depression improvements: a retrospective longitudinal case series.

Treatment-resistant depression is a severe form of major depressive disorder and deep brain stimulation is currently an investigational treatment. The stimulation's therapeutic effect may be explained through the functional and structural connectivities between the stimulated area and other brain regions, or to depression-associated networks. In this longitudinal, retrospective study, four female patients with treatment-resistant depression were implanted for stimulation in the nucleus accumbens area at our center. We analyzed the structural and functional connectivity of the stimulation area: the structural connectivity was investigated with probabilistic tractography; the functional connectivity was estimated by combining patient-specific stimulation volumes and a normative functional connectome. These structural and functional connectivity profiles were then related to four clinical outcome scores. At 1-year follow-up, the remission rate was 66%. We observed a consistent structural connectivity to Brodmann area 25 in the patient with the longest remission phase. The functional connectivity analysis resulted in patient-specific R-maps describing brain areas significantly correlated with symptom improvement in this patient, notably the prefrontal cortex. But the connectivity analysis was mixed across patients, calling for confirmation in a larger cohort and over longer time periods.

Programming of subthalamic nucleus deep brain stimulation with hyperdirect pathway and corticospinal tract-guided parameter suggestions.

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is an effective treatment for advanced Parkinson's disease. Stimulation of the hyperdirect pathway (HDP) may mediate the beneficial effects, whereas stimulation of the corticospinal tract (CST) mediates capsular side effects. The study's objective was to suggest stimulation parameters based on the activation of the HDP and CST. This retrospective study included 20 Parkinson's disease patients with bilateral STN DBS. Patient-specific whole-brain probabilistic tractography was performed to extract the HDP and CST. Stimulation parameters from monopolar reviews were used to estimate volumes of tissue activated and to determine the streamlines of the pathways inside these volumes. The activated streamlines were related to the clinical observations. Two models were computed, one for the HDP to estimate effect thresholds and one for the CST to estimate capsular side effect thresholds. In a leave-one-subject-out cross-validation, the models were used to suggest stimulation parameters. The models indicated an activation of 50% of the HDP at effect threshold, and 4% of the CST at capsular side effect threshold. The suggestions for best and worst levels were significantly better than random suggestions. Finally, we compared the suggested stimulation thresholds with those from the monopolar reviews. The median suggestion errors for the effect threshold and side effect threshold were 1 and 1.5 mA, respectively. Our stimulation models of the HDP and CST suggested STN DBS settings. Prospective clinical studies are warranted to optimize tract-guided DBS programming. Together with other modalities, these may allow for assisted STN DBS programming.

Probabilistic Mapping Reveals Optimal Stimulation Site in Essential Tremor.

OBJECTIVE: The objective of this study was to obtain individual clinical and neuroimaging data of patients undergoing deep brain stimulation (DBS) for essential tremor (ET) from 5 different European centers to identify predictors of outcome and to identify an optimal stimulation site. METHODS: We analyzed retrospectively baseline covariates, pre- and postoperative clinical tremor scores (for 12 months) as well as individual imaging data from 119 patients to obtain individual electrode positions and stimulation volumes. Individual imaging and clinical data were used to calculate a probabilistic stimulation map in normalized space using voxel-wise statistical analysis. Finally, we used this map to train a classifier to predict tremor improvement. RESULTS: Probabilistic mapping of stimulation effects yielded a statistically significant cluster that was associated with a tremor improvement >50%. This cluster of optimal stimulation extended from the posterior subthalamic area to the ventralis intermedius nucleus and coincided with a normative structural connectivity-based cerebellothalamic tract (CTT). The combined features "distance between the stimulation volume and the significant cluster" and "CTT activation" were used as a predictor of tremor improvement. This correctly classified a >50% tremor improvement with a sensitivity of 89% and a specificity of 57%. INTERPRETATION: Our multicenter ET probabilistic stimulation map identified an area of optimal stimulation along the course of the CTT. The results of this study are mainly descriptive until confirmed in independent datasets, ideally through prospective testing. This target will be made openly available and may be used to guide surgical planning and for computer-assisted programming of DBS in the future. ANN NEUROL 2022;91:602-612.

Spectral Topography of the Subthalamic Nucleus to Inform Next-Generation Deep Brain Stimulation.

BACKGROUND: The landscape of neurophysiological symptoms and behavioral biomarkers in basal ganglia signals for movement disorders is expanding. The clinical translation of sensing-based deep brain stimulation (DBS) also requires a thorough understanding of the anatomical organization of spectral biomarkers within the subthalamic nucleus (STN). OBJECTIVES: The aims were to systematically investigate the spectral topography, including a wide range of sub-bands in STN local field potentials (LFP) of Parkinson's disease (PD) patients, and to evaluate its predictive performance for clinical response to DBS. METHODS: STN-LFPs were recorded from 70 PD patients (130 hemispheres) awake and at rest using multicontact DBS electrodes. A comprehensive spatial characterization, including hot spot localization and focality estimation, was performed for multiple sub-bands (delta, theta, alpha, low-beta, high-beta, low-gamma, high-gamma, and fast-gamma (FG) as well as low- and fast high-frequency oscillations [HFO]) and compared to the clinical hot spot for rigidity response to DBS. A spectral biomarker map was established and used to predict the clinical response to DBS. RESULTS: The STN shows a heterogeneous topographic distribution of different spectral biomarkers, with the strongest segregation in the inferior-superior axis. Relative to the superiorly localized beta hot spot, HFOs (FG, slow HFO) were localized up to 2 mm more inferiorly. Beta oscillations are spatially more spread compared to other sub-bands. Both the spatial proximity of contacts to the beta hot spot and the distance to higher-frequency hot spots were predictive for the best rigidity response to DBS. CONCLUSIONS: The spatial segregation and properties of spectral biomarkers within the DBS target structure can additionally be informative for the implementation of next-generation sensing-based DBS. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Probabilistic Subthalamic Nucleus Stimulation Sweet Spot Integration Into a Commercial Deep Brain Stimulation Programming Software Can Predict Effective Stimulation Parameters.

OBJECTIVES: Subthalamic nucleus (STN) deep brain stimulation (DBS) programming in patients with Parkinson disease (PD) may be challenging, especially when using segmented leads. In this study, we integrated a previously validated probabilistic STN sweet spot into a commercially available software to evaluate its predictive value for clinically effective DBS programming. MATERIALS AND METHODS: A total of 14 patients with PD undergoing bilateral STN DBS with segmented leads were included. A nonlinear co-registration of a previously defined probabilistic sweet spot onto the manually segmented STN was performed together with lead reconstruction and tractography of the corticospinal tract (CST) in each patient. Contacts were ranked (level and direction), and corresponding effect and side-effect thresholds were predicted based on the overlap of the volume of activated tissue (VTA) with the sweet spot and CST. Image-based findings were correlated with postoperative clinical testing results during monopolar contact review and chronic stimulation parameter settings used after 12 months. RESULTS: Image-based contact prediction showed high interrater reliability (Cohen kappa 0.851-0.91). Image-based and clinical ranking of the most efficient ring level and direction of stimulation were matched in 72% (95% CI 57.0-83.3) and 65% (95% CI 44.9-81.2), respectively, across the whole cohort. The mean difference between the predicted and clinically observed effect thresholds was 0.79 ± 0.69 mA (p = 0.72). The median difference between the predicted and clinically observed side-effect thresholds was -0.5 mA (p < 0.001, Wilcoxon paired signed rank test). CONCLUSIONS: Integration of a probabilistic STN functional sweet spot into a surgical programming software shows a promising capability to predict the best level and directional contact(s) as well as stimulation settings in DBS for PD and could be used to optimize programming with segmented lead technology. This integrated image-based programming approach still needs to be evaluated on a bigger data set and in a future prospective multicenter cohort.

Combining Multimodal Biomarkers to Guide Deep Brain Stimulation Programming in Parkinson Disease.

BACKGROUND: Deep brain stimulation (DBS) programming of multicontact DBS leads relies on a very time-consuming manual screening procedure, and strategies to speed up this process are needed. Beta activity in subthalamic nucleus (STN) local field potentials (LFP) has been suggested as a promising marker to index optimal stimulation contacts in patients with Parkinson disease. OBJECTIVE: In this study, we investigate the advantage of algorithmic selection and combination of multiple resting and movement state features from STN LFPs and imaging markers to predict three relevant clinical DBS parameters (clinical efficacy, therapeutic window, side-effect threshold). MATERIALS AND METHODS: STN LFPs were recorded at rest and during voluntary movements from multicontact DBS leads in 27 hemispheres. Resting- and movement-state features from multiple frequency bands (alpha, low beta, high beta, gamma, fast gamma, high frequency oscillations [HFO]) were used to predict the clinical outcome parameters. Subanalyses included an anatomical stimulation sweet spot as an additional feature. RESULTS: Both resting- and movement-state features contributed to the prediction, with resting (fast) gamma activity, resting/movement-modulated beta activity, and movement-modulated HFO being most predictive. With the proposed algorithm, the best stimulation contact for the three clinical outcome parameters can be identified with a probability of almost 90% after considering half of the DBS lead contacts, and it outperforms the use of beta activity as single marker. The combination of electrophysiological and imaging markers can further improve the prediction. CONCLUSION: LFP-guided DBS programming based on algorithmic selection and combination of multiple electrophysiological and imaging markers can be an efficient approach to improve the clinical routine and outcome of DBS patients.

Single-center study: evaluation of sonography in Budd-Chiari syndrome.

PURPOSE: Budd-Chiari syndrome (BCS) is a rare disease characterized by hepatic venous outflow tract obstruction. The study aimed to evaluate the diagnostic utility of ultrasound in confirming the diagnosis of BCS and to provide an overview of the clinical picture. MATERIALS AND METHOD: In this retrospective single-center study, patients with an initial diagnosis of BCS were included. The files were analyzed concerning the ultrasound images and compared to computed tomography (CT) and magnetic resonance imaging (MRI). Main clinical signs of BCS were collected. RESULTS: Data of 25 patients were analyzed. Doppler sonography showed the highest sensitivity (78.9%) with the highest specificity 97.4 (%) in confirming the correct diagnosis of BCS. Main imaging signs were obstruction in the hepatic veins (68.0%, 17/25 thrombotic), collaterals (91.7%, 11/12 intrahepatic), inhomogeneous liver parenchyma (7/21), and a hypertrophied lobus caudatus (18/21) (p < 0.01). All imaging signs could be detected with sonography. Hypertrophied lobus caudatus was seen exclusively in BCS. Furthermore, portal hypertension (9/25), liver cirrhosis (9/25), and ascites (19/25) can be diagnosed as non-specific signs of BCS (p < 0.01).The main clinical findings were elevated γ-GT levels in the laboratory (92.0%, 23/25, p < 0.01) and esophageal varices in endoscopy (12/25 p < 0.01). An association with myeloproliferative neoplasia (MPN) was frequently seen (10/25) (p < 0.01). CONCLUSION: The present study demonstrates that sonography is an appropriate tool for the diagnosis of BCS and should be used as the first imaging procedure.

Proactive inhibition is not modified by deep brain stimulation for Parkinson's disease: An electrical neuroimaging study.

In predictable contexts, motor inhibitory control can be deployed before the actual need for response suppression. The brain functional underpinnings of proactive inhibition, and notably the role of basal ganglia, are not entirely identified. We investigated the effects of deep brain stimulation of the subthalamic nucleus or internal globus pallidus on proactive inhibition in patients with Parkinson's disease. They completed a cued go/no-go proactive inhibition task ON and (unilateral) OFF stimulation while EEG was recorded. We found no behavioural effect of either subthalamic nucleus or internal globus pallidus deep brain stimulation on proactive inhibition, despite a general improvement of motor performance with subthalamic nucleus stimulation. In the non-operated and subthalamic nucleus group, we identified periods of topographic EEG modulation by the level of proactive inhibition. In the subthalamic nucleus group, source estimation analysis suggested the initial involvement of bilateral frontal and occipital areas, followed by a right lateralized fronto-basal network, and finally of right premotor and left parietal regions. Our results confirm the overall preservation of proactive inhibition capacities in both subthalamic nucleus and internal globus pallidus deep brain stimulation, and suggest a partly segregated network for proactive inhibition, with a preferential recruitment of the indirect pathway.

International Multicenter Analysis of Brain Structure Across Clinical Stages of Parkinson's Disease.

BACKGROUND: Brain structure abnormalities throughout the course of Parkinson's disease have yet to be fully elucidated. OBJECTIVE: Using a multicenter approach and harmonized analysis methods, we aimed to shed light on Parkinson's disease stage-specific profiles of pathology, as suggested by in vivo neuroimaging. METHODS: Individual brain MRI and clinical data from 2357 Parkinson's disease patients and 1182 healthy controls were collected from 19 sources. We analyzed regional cortical thickness, cortical surface area, and subcortical volume using mixed-effects models. Patients grouped according to Hoehn and Yahr stage were compared with age- and sex-matched controls. Within the patient sample, we investigated associations with Montreal Cognitive Assessment score. RESULTS: Overall, patients showed a thinner cortex in 38 of 68 regions compared with controls (dmax  = -0.20, dmin  = -0.09). The bilateral putamen (dleft  = -0.14, dright  = -0.14) and left amygdala (d = -0.13) were smaller in patients, whereas the left thalamus was larger (d = 0.13). Analysis of staging demonstrated an initial presentation of thinner occipital, parietal, and temporal cortices, extending toward rostrally located cortical regions with increased disease severity. From stage 2 and onward, the bilateral putamen and amygdala were consistently smaller with larger differences denoting each increment. Poorer cognition was associated with widespread cortical thinning and lower volumes of core limbic structures. CONCLUSIONS: Our findings offer robust and novel imaging signatures that are generally incremental across but in certain regions specific to disease stages. Our findings highlight the importance of adequately powered multicenter collaborations. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Subthalamic nucleus activity dynamics and limb movement prediction in Parkinson's disease.

Whilst exaggerated bursts of beta frequency band oscillatory synchronization in the subthalamic nucleus have been associated with motor impairment in Parkinson's disease, a plausible mechanism linking the two phenomena has been lacking. Here we test the hypothesis that increased synchronization denoted by beta bursting might compromise information coding capacity in basal ganglia networks. To this end we recorded local field potential activity in the subthalamic nucleus of 18 patients with Parkinson's disease as they executed cued upper and lower limb movements. We used the accuracy of local field potential-based classification of the limb to be moved on each trial as an index of the information held by the system with respect to intended action. Machine learning using the naïve Bayes conditional probability model was used for classification. Local field potential dynamics allowed accurate prediction of intended movements well ahead of their execution, with an area under the receiver operator characteristic curve of 0.80 ± 0.04 before imperative cues when the demanded action was known ahead of time. The presence of bursts of local field potential activity in the alpha, and even more so, in the beta frequency band significantly compromised the prediction of the limb to be moved. We conclude that low frequency bursts, particularly those in the beta band, restrict the capacity of the basal ganglia system to encode physiologically relevant information about intended actions. The current findings are also important as they suggest that local subthalamic activity may potentially be decoded to enable effector selection, in addition to force control in restorative brain-machine interface applications.

Long-Term Outcome and Neuroimaging of Deep Brain Stimulation in Holmes Tremor: A Case Series.

BACKGROUND: Different deep brain stimulation (DBS) targets have been suggested as treatment for patients with pharmacologically refractory Holmes tremor (HT). We report the clinical and quality of life (QoL) long-term (up to nine years) outcome in four patients with HT treated with DBS (in thalamic ventral intermediate nucleus-VIM or in dentato-rubro-thalamic tract-DRTT). MATERIALS AND METHODS: The patients underwent routine clinical evaluations before and after DBS (typically annually). Tremor severity and activities of daily living (ADL) were quantified by the Fahn-Tolosa-Marin Tremor-Rating-Scale (FTMTRS). QoL was assessed using the RAND SF-36-item Health Survey (RAND SF-36). In addition, we computed, in all four patients, the VTA based on the best stimulation settings using heuristic approaches included in the open source toolbox LEAD-DBS. RESULTS: In all patients, tremor and ADL improved significantly at one-year post-DBS follow-up (34-61% improvement in FTMTRS total score compared to baseline). In three out of four patients, the improvement of tremor was sustained no longer than two to three years and only in one patient was sustained up to nine years. In this patient, the largest intersection between VTA and DBS target has been observed. Scores for ADL deteriorated over the course of time, reaching worse levels compared to baseline already during the three-year post-DBS follow-up, in three out of four patients. Physical and mental health component scores of RAND SF-36 had very different outcome between patients and follow-ups and were not associated with tremor-related outcomes. CONCLUSIONS: The benefits of DBS in HT might not be always long lasting. Although QoL slightly improved, this change seemed to be independent of the motor outcome following DBS. The estimation of DBS target and VTA proximity could be a useful tool for DBS clinicians in order to facilitate the DBS programming process and optimize DBS treatment.

Point of Care Ultrasound in Geriatric Patients: Prospective Evaluation of a Portable Handheld Ultrasound Device.

PURPOSE: The aim of the current study was to evaluate point of care ultrasound (POCUS) in geriatric patients by echoscopy using a handheld ultrasound device (HHUSD, VScan) at bedside in comparison to a high-end ultrasound system (HEUS) as the gold standard. MATERIALS AND METHODS: Prospective observational study with a total of 112 geriatric patients. The ultrasound examinations were independently performed by two experienced blinded examiners with a portable handheld device and a high-end ultrasound device. The findings were compared with respect to diagnostic findings and therapeutic implications. RESULTS: The main indications for the ultrasound examinations were dyspnea (44.6 %), fall (frailty) (24.1 %) and fever (21.4 %). The most frequently found diagnoses were cystic lesions 32.1 % (35/109), hepatic vein congestion 19.3 % (21/109) and ascites 13.6 % (15/110). HHUSD delivered 13 false-negative findings in the abdomen resulting in an "overall sensitivity" of 89.5 %. The respective "overall specificity" was 99.6 % (7 false-positive diagnoses). HHUSD (versus HEUS data) resulted in 13.6 % (17.3 %) diagnostically relevant procedures in the abdomen and 0.9 % (0.9 %) in the thorax. Without HHUSD (HEUS) 95.7 % (100 %) of important pathological findings would have been missed. CONCLUSION: The small HHUSD tool improves clinical decision-making in immobile geriatric patients at the point of care (geriatric ward). In most cases, HHUSD allows sufficiently accurate yes/no diagnoses already at the bedside, thereby clarifying the leading symptoms for early clinical decision-making.

Effects of bilateral stimulation of the subthalamic nucleus in Parkinson's disease with and without REM sleep behaviour disorder.

BACKGROUND: Although rapid eye movement sleep behaviour disorder (RBD) in Parkinson's disease (PD) is associated with increased non-motor symptoms, its impact on the deep brain stimulation (DBS) outcome remains unclear. This is the first study to compare the post-DBS outcome between PD patients with RBD (PD-RBD+) and without (PD-RBD-). METHODS: We analysed data from PD patients who were treated with bilateral DBS in the nucleus subthalamicus. Assessments included night-polysomnography (only pre-DBS), and motor and non-motor assessments pre-DBS and post-DBS. RESULTS: Among 50 PD patients (29 males, mean age 62.5 years, 11.8 mean PD years), 24 (48%) had RBD. Pre-DBS, the two groups were equal in respect to sociodemographic features, disease duration and PD medications. A multivariate analysis showed that the clinical profile linked to motor, non-motor and quality of life features differed significantly between PD patients with and without RBD. The most discriminative elements were Unified Parkinson's Disease Rating Scale (UPDRS)-III, apathy and depression scores. Post-DBS, UPDRS-III, Epworth sleepiness scale and PD questionnaire improved significantly in both groups. UPDRS-II scores significantly improved in the PD-RBD+ group (-45%) but remained unchanged in the PD-RBD- group (-14%). The depression score improved significantly in the PD-RBD+ (-34%) and remained unchanged in the PD-RBD- group. The apathy score remained unchanged in the PD-RBD+ group but increased significantly in the PD-RBD- group (+33%). CONCLUSION: While pre-DBS, PD patients with and without RBD showed different clinical profiles, post-DBS, the clinical profiles were comparable between the two groups. In respect to depressive symptoms, apathy and activities of daily living, PD-RBD+ patients show favourable post-DBS outcome. These findings highlight the importance of RBD assessment prior to DBS surgery.

Contrast-enhanced imaging in hepatic epithelioid hemangioendothelioma: retrospective study of 10 patients.

PURPOSE: The purpose of this study was to analyze imaging findings in hepatic epithelioid hemangioendothelioma (HEHE) with a particular focus on contrast-enhanced ultrasound (CEUS). MATERIALS AND METHODS: This retrospective multicenter study included 10 patients with histologically proven HEHE from 5 European centers. All existing ultrasound images/videos were independently analyzed by 2 experienced examiners (DEGUM level III, internal medicine) using a standardized evaluation form. Patterns of contrast enhancement were correlated with computed tomography (CT), magnetic resonance imaging (MRI), and pathological findings. RESULTS: B-mode ultrasound, CEUS, CT, and MRI were performed in 90 %, 70 %, 100 %, and 90 % of patients, respectively. Multifocal HEHE could be observed in 80 % with affection of both liver lobes in 70 %. Analysis of CEUS revealed 3 characteristic patterns that correlated well with contrast patterns on CT and MRI: (a) peripheral nodular enhancement with centripetal fill-in and wash-out in the portal venous and late venous phase (PVLP), (b) rim-like arterial enhancement with wash-out in the PVLP, and (c) inversed target sign with/without wash-out in the PVLP. Wash-out in the PVLP as a sign suspicious of malignancy was observed in 6/7 patients (85.7 %). CONCLUSIONS: Knowledge of the different characteristic CEUS patterns is of importance to avoid misdiagnosis due to resemblance of patterns A and B to the much more common focal liver lesions hemangioma and intrahepatic cholangiocarcinoma. Of importance, sonographers should be aware that wash-out in the PVLP might be absent in some patients.

Outcomes of three different ways to train medical students as ultrasound tutors.

BACKGROUND: In order to provide faculty-wide undergraduate ultrasound training in times of scarce resources, many medical faculties employ trained peer-student tutors to oversee the hands-on training. However, data to guide the training of ultrasound peer-student tutors are scarce. We conducted a prospective quasi-randomized study to assess the gain in theoretical knowledge and practical scanning skills of peer-student tutors who were trained with a course only, an internship only, or the combination of a course and an internship. METHODS: A total of 44 peer-student tutors were trained by a one-week course only (C-Group, n = 21), by an internship only (I-Group, n = 10) or by a course and an internship (CI-Group, n = 13). Prior to and after the completion of the training the peer-student tutors completed an MC-test (theoretical knowledge) and an OSCE (practical scanning skills). RESULTS: With all three education concepts, the peer-student tutors had significant and comparable gains in theoretical knowledge (C-group + 90%, I-group + 61.5%, CI-group + 114.0%) and practical scanning skills (C-group + 112.0%, I-group + 155.0% and CI-group + 123.5%), all p < 0.001. CONCLUSION: Peer-student tutors, who were trained with a course or an internship or a course and internship improved their theoretical knowledge and their practical scanning skills significantly and to a comparable degree.

Development and implementation of a comprehensive ultrasound curriculum for undergraduate medical students - a feasibility study.

BACKGROUND: Ultrasound is one of the most important imaging techniques in clinical medicine with unique advantages. Skills in ultrasound imaging are very usefull for physicians including novices and thus also mandated by the Task Force "National Competence-Based Learning Objectives for Undergraduate Medical Education" (NKLM) in Germany and as well as by the German Ultrasound Society (Deutsche Gesellschaft für Ultraschall in der Medizin, DEGUM). Since ultrasound is best learned hands-on in very small supervised groups, we developed and implemented a comprehensive ultrasound-curriculum for all undergraduate medical students of our faculty using a peer-teaching concept. METHODS: We used Kern's six-step model of curricular development comprising (1) problem identification and general needs assessment, (2) needs assessment of the targeted learners, (3) goals and objectives, (4) educational stategies, (5) implementation, and (6) evaluation and feedback. RESULTS: The developed curriculum covers basic ultrasound of the abdomen and the throat, eFAST (Extended Focused Assessment with Sonography for Trauma), lung-ultrasound, FEEL (Focused Echocardiography in Emergency Life Support) and compression duplex sonography of the thigh deep vein system. All 5th year medical students receive a 90 min lecture on ultrasound basics by a faculty member and then a 12.5 h hands-on course divided into three sessions with one student tutor for every 4 students. The students are provided with a script (PDF-File) that covers all the learning goals, including example images of pathologies. The student tutors are trained during a 1 week ultrasound course and a 21-day rotation through seven different ultrasound laboratories. In addition, they undergo a standardized 1.5 day didactical training. Prior to the implementation for all students, the overall course was tested on 27 volunteer students. These students rated (on a 6-point Likert scale from 1 = excellent to 6 = very poor) the satisfaction with the student tutors and the faculty members as 1.4 ± .9 (mean ± stddev) and 1.3 ± .5 respectively. CONCLUSION: A comprehensive ultrasound curriculum for all undergraduate medical students using a peer-teaching concept is feasible. Further studies are needed to evaluate in detail the learning outcomes for students and student tutors.

Directional local field potentials: A tool to optimize deep brain stimulation.

BACKGROUND: Although recently introduced directional DBS leads provide control of the stimulation field, programing is time-consuming. OBJECTIVES: Here, we validate local field potentials recorded from directional contacts as a predictor of the most efficient contacts for stimulation in patients with PD. METHODS: Intraoperative local field potentials were recorded from directional contacts in the STN of 12 patients and beta activity compared with the results of the clinical contact review performed after 4 to 7 months. RESULTS: Normalized beta activity was positively correlated with the contact's clinical efficacy. The two contacts with the highest beta activity included the most efficient stimulation contact in up to 92% and that with the widest therapeutic window in 74% of cases. CONCLUSION: Local field potentials predict the most efficient stimulation contacts and may provide a useful tool to expedite the selection of the optimal contact for directional DBS. © 2017 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.

Deep Brain Stimulation for Tremor: Is There a Common Structure?

BACKGROUND: Subthalamic nucleus (STN) stimulation has been recognized to control resting tremor in Parkinson disease. Similarly, thalamic stimulation (ventral intermediate nucleus; VIM) has shown tremor control in Parkinson disease, essential, and intention tremors. Recently, stimulation of the posterior subthalamic area (PSA) has been associated with excellent tremor control. Thus, the optimal site of stimulation may be located in the surrounding white matter. AIMS: The objective of this work was to investigate the area of stimulation by determining the contact location correlated with the best tremor control in STN/VIM patients. METHODS: The mean stimulation site and related volume of tissue activated (VTA) of 25 tremor patients (STN or VIM) were projected on the Morel atlas and compared to stimulation sites from other tremor studies. RESULTS: All patients showed a VTA that covered ≥50% of the area superior and medial to the STN or inferior to the VIM. Our stimulation areas suggest involvement of the more lateral and superior part of the dentato-rubro-thalamic tract (DRTT), whereas targets described in other studies seem to involve the DRTT in its more medial and inferior part when it crosses the PSA. CONCLUSIONS: According to anatomical and diffusion tensor imaging data, the DRTT might be the common structure stimulated at different portions within the PSA/caudal zona incerta.

[Geriatric ultrasound]. / Geriatrischer Ultraschall.

In geriatric patients, ultrasound is the appropriate diagnostic technique to detect and to follow-up underlying and accompanying diseases of the heart, lung, liver, kidneys, pancreas, gastrointestinal tract and of arterial and venous vessels. Based on a systematic survey of the published literature, this review describes the value of ultrasound in geriatric patients focussing on point of care.