Whole-brain mapping of increased manganese levels in welders and its association with exposure and motor function.

Although manganese (Mn) is a trace metal essential for humans, chronic exposure to Mn can cause accumulation of this metal ion in the brain leading to an increased risk of neurological and neurobehavioral health effects. This is a concern for welders exposed to Mn through welding fumes. While brain Mn accumulation in occupational settings has mostly been reported in the basal ganglia, several imaging studies also revealed elevated Mn in other brain areas. Since Mn functions as a magnetic resonance imaging (MRI) T1 contrast agent, we developed a whole-brain MRI approach to map in vivo Mn deposition differences in the brains of non-exposed factory controls and exposed welders. This is a cross-sectional analysis of 23 non-exposed factory controls and 36 exposed full-time welders from the same truck manufacturer. We collected high-resolution 3D MRIs of brain anatomy and R1 relaxation maps to identify regional differences using voxel-based quantification (VBQ) and statistical parametric mapping. Furthermore, we investigated the associations between excess Mn deposition and neuropsychological and motor test performance. Our results indicate that: (1) Using whole-brain MRI relaxometry methods we can generate excess Mn deposition maps in vivo, (2) excess Mn accumulation due to occupational exposure occurs beyond the basal ganglia in cortical areas associated with motor and cognitive functions, (3) Mn likely diffuses along white matter tracts in the brain, and (4) Mn deposition in specific brain regions is associated with exposure (cerebellum and frontal cortex) and motor metrics (cerebellum and hippocampus).

[Certification by the German Society for Neurorehabiliation, DGNR : Performance and quality of the "Centers for weaning from a ventilator in early neurological and neurosurgical rehabilitation"]. / Zertifizierung der Deutschen Gesellschaft für Neurorehabilitation e. V., DGNR : Leistung und Qualität der "Zentren für Beatmungsentwöhnung in der neurologisch-neurochirurgischen Frührehabilitation".

BACKGROUND: Certification of centers for weaning from a ventilator in neurological neurosurgical early rehabilitation (NNER) by the German Society for Neurorehabilitation (DGNR) is possible since 1 October 2021. OBJECTIVE: The results of certification of facilities in the first year after starting the procedure are presented. MATERIAL AND METHODS: As part of the certification process 28 criteria are assessed including a set of mandatory characteristics of the facility. The criteria are divided into structural criteria (i = 7), diagnostic criteria (i = 6), personnel criteria (i = 3), internal organization criteria (i = 7), and quality management criteria (i = 5). RESULTS: A total of 13 centers were certified in the first year, with a combined total of 283 beds for weaning from a ventilator in the NNER and served 2278 persons to be weaned from a ventilator in the year before certification, with a median of 134 per facility (range 44-414). Only rarely was weaning unsuccessful, requiring conversion to home mechanical ventilation before discharge (invasive home mechanical ventilation median per facility 10 persons, range 2-25; non-invasive home mechanical ventilation median 0 persons, range 0-57). A high level of process and structural quality was documented for the certified centers: across all areas of assessment, the individual certification criteria were met in the vast majority of cases (median degree of complete fulfilment 86%) or met with improvement potentials documented by the auditors (median 11%). CONCLUSION: Successful weaning in NNER and a high level of process and structural quality can be demonstrated by the certification results of centers that follow this integrative approach to weaning from a ventilator in a NNER setting.

[Physician-led healthcare structures for patients in out-of-hospital intensive care nursing: a cross-sectional survey by the German Society for Out-of-Hospital Ventilation]. / Versorgung von Patient*innen der Außerklinischen Intensivpflege in ärztlich geleiteten Einrichtungen ­ eine Querschnitterhebung der Deutschen Interdisziplinären Gesellschaft für Außerklinische Beatmung.

BACKGROUND: Patients in out-of-hospital intensive care are usually provided with a tracheal cannula and often additionally receive mechanical ventilation. Less frequently, they receive non-invasive ventilation. Their potential to be weaned from the ventilator and to have their tracheostomy tubes removed must be evaluated twice per year from January 1, 2025 on. If there is a potential for weaning from mechanical ventilation or removal of the tracheostomy tube, referral to a specialized facility is required. OBJECTIVE: The study aimed at characterizing the specialized institutions which can evaluate the potential of patients to be weaned from the ventilator and to have their tracheostomy tubes removed, and which can perform these tasks as well. METHODS: Under the auspices of the German Interdisciplinary Society for Out-of-Hospital Ventilation (DIGAB) and with support from the Working group early neurological-neurosurgical rehabilitation (ENNR) a crosssectional online survey took place. RESULTS: Of 18 participating institutions, 11 (61.1%) were certified by professional societies representing neurorehabilitation, respiratory medicine, anaesthesiology and intensive care or paraplegiology. Most leading physicians were specialists in neurology, followed by pulmonology, anaesthesiology and paediatrics. Many professions with a variety of qualifications worked in these institutions. According to n=10 (55.6%) of the participating instituions, regional treatment capacities for patients from out-of-hospital intensive care, who need hospital admission for weaning from mechanical ventilation or a tracheal cannula, were not sufficient. About one third of the institutions offered televisits. DISCUSSION: Patients in out-of-hospital intensive care need interdisciplinary care, interconnecting out- and inpatient care structures due to medical complexity and participation restrictions. While interdisciplinary teams and a wide spectrum of diagnostic and therapeutic methods were provided in the participating institutions, their structure differed considerably. CONCLUSION: Quality criteria should be established for centres evaluating the patients' potential to be weaned from the ventilator and to have their tracheostomy tubes removed and performing weaning from mechanical ventilation and tracheal cannulas. Further research is needed to specify those criteria, to quantify inpatient treatment capacities for patients from out-of-hospital intensive care to be weaned from mechanical ventilation or tracheal cannulas,to evaluate the feasibility of weaning from mechanical ventilation and tracheal cannulas in an out-of-hospital setting and to understand the role of telemedicine in the treatment of patients in out-of-hospital intensive care.

Temporal dynamics of oscillatory activity during nonlexical language decoding: Evidence from Morse code and magnetoencephalography.

Understanding encoded languages, such as written script or Morse code, requires nonlexical and lexical processing components that act in a parallel and interactive fashion. Decoding written script-as for example in reading-is typically very fast, making the investigation of the lexical and nonlexical components and their underlying neural mechanisms challenging. In the current study, we aimed to accomplish this problem by using Morse code as a model for language decoding. The decoding of Morse code is slower and thus allows a better and more fine-grained investigation of the lexical and nonlexical components of language decoding. In the current study, we investigated the impact of various components of nonlexical decoding of Morse code using magnetoencephalography. For this purpose, we reconstructed the time-frequency responses below 40 Hz in brain regions significantly involved in Morse code decoding and word comprehension that were identified in a previous study. Event-related reduction in beta- and alpha-band power were found in left inferior frontal cortex and angular gyrus, respectively, while event-related theta-band power increase was found at frontal midline. These induced oscillations reflect working-memory encoding, long-term memory retrieval as well as demanding cognitive control, respectively. In sum, by using Morse code and MEG, we were able to identify a cortical network underlying language decoding in a time- and frequency-resolved manner.

Altered social decision making in patients with chronic pain.

BACKGROUND: Chronic pain affects up to 20% of the population, impairs quality of life and reduces social participation. Previous research reported that pain-related perceived injustice covaries with these negative consequences. The current study probed whether chronic pain patients responded more strongly to disadvantageous social inequity than healthy individuals. METHODS: We administered the Ultimatum Game, a neuroeconomic social exchange game, where a sum of money is split between two players to a large sample of patients with chronic pain disorder with somatic and psychological factors (n = 102) and healthy controls (n = 101). Anonymised, and in truth experimentally controlled, co-players proposed a split, and our participants either accepted or rejected these offers. RESULTS: Chronic pain patients were hypersensitive to disadvantageous inequity and punished their co-players for proposed unequal splits more often than healthy controls. Furthermore, this systematic shift in social decision making was independent of patients' performance on tests of executive functions and risk-sensitive (non-social) decision making . CONCLUSIONS: Our findings indicate that chronic pain is associated with anomalies in social decision making (compared to healthy controls) and hypersensitivity to social inequity that is likely to negatively impact social partaking and thereby the quality of life.

[The Respiratory Therapist in Neurology An Evolving Specialization in Germany]. / Der Atmungstherapeut in der Neurologie ­ Ein Blick auf das Berufsbild und ein Ausblick in die Zukunft.

In Germany, nurses, physiotherapists and speech and language therapists follow a qualifying training for about 1,5 years to become respiratory therapists (RTs). With respect to neurological illness, RTs diagnose and treat disorders of respiration, cough and swallowing as well as a retention of tracheobronchial secretions. There is an increasing demand for RTs in neurology, in neurointensive care and in neurological and neurosurgical early rehabilitation. The certification of specialized centers for weaning in neurological and neurosurgical early rehabilitation was introduced by the German Society for Neurorehabilitation (DGNR) in 2021. As a certification criterion it includes the employment of a respiratory therapists. In neurological organizations treating critically and severely ill patients, RTs work at an important interdisciplinary intersection of physicians, nurses and therapists. RTs are qualified to train teams, patients and family caregivers and to establish care structures for critically and severely ill neurological patients. Due to the complexity of neurological illnesses RTs working in neurological institutions need specific qualification. Specific training for RTs in neurology and neurorehabilitation might improve care for critically and severely ill neurological patients. Further professionalization of RT in Germany requires standardizing curricula, a professional society for RTs and, finally, academization.

Optimizing home-based long-term intensive care for neurological patients with neurorehabilitation outreach teams - protocol of a multicenter, parallel-group randomized controlled trial (OptiNIV-Study).

BACKGROUND: Even with high standards of acute care and neurological early rehabilitation (NER) a substantial number of patients with neurological conditions still need mechanical ventilation and/or airway protection by tracheal cannulas when discharged and hence home-based specialised intensive care nursing (HSICN). It may be possible to improve the home care situation with structured specialized long-term neurorehabilitation support and following up patients with neurorehabilitation teams. Consequently, more people might recover over an extended period to a degree that they were no longer dependent on HSICN. METHODS: This healthcare project and clinical trial implements a new specialised neurorehabilitation outreach service for people being discharged from NER with the need for HSICN. The multicentre, open, parallel-group RCT compares the effects of one year post-discharge specialized outpatient follow-up to usual care in people receiving HSICN. Participants will randomly be assigned to receive the new form of healthcare (intervention) or the standard healthcare (control) on a 2:1 basis. Primary outcome is the rate of weaning from mechanical ventilation and/or decannulation (primary outcome) after one year, secondary outcomes include both clinical and economic measures. 173 participants are required to corroborate a difference of 30 vs. 10% weaning success rate statistically with 80% power at a 5% significance level allowing for 15% attrition. DISCUSSION: The OptiNIV-Study will implement a new specialised neurorehabilitation outreach service and will determine its weaning success rates, other clinical outcomes, and cost-effectiveness compared to usual care for people in need for mechanical ventilation and/or tracheal cannula and hence HSICN after discharge from NER. TRIAL REGISTRATION: The trial OptiNIV has been registered in the German Clinical Trials Register (DRKS) since 18.01.2022 with the ID DRKS00027326 .

[The certification of centers for weaning from mechanical ventilation in neurological and neurosurgical early rehabilitation by the German Society for Neurorehabilitation]. / Die Zertifizierung von Zentren für Beatmungsentwöhnung in der neurologisch-neurochirurgischen Frührehabilitation durch die Deutsche Gesellschaft für Neurorehabilitation.

Specialized centers for weaning in neurological and neurosurgical early rehabilitation can be certified by the German Society for Neurorehabilitation (DGNR) since 1 October 2021. The certification criteria are indicators for structure and process quality and for treatment results for weaning of neurological patients from mechanical ventilation. In Germany these patients are treated in departments for neurological and neurosurgical early rehabilitation in acute care hospitals as well as in specialized rehabilitation hospitals. Acknowledging this diversity of care, certification is possible for both kinds of institutions. Certification is granted by the DGNR in cooperation with TÜV Rheinland as the certification authority, analogous to the certification of stroke units. Institutions apply for certification by sending all necessary documents to the TÜV Rheinland. Afterwards auditors of the TÜV Rheinland (lead auditor) and the DGNR (medical speciality auditor) visit the institution on site. The results of this visit are reported to the certification committee of the DGNR, which in turn recommends or declines certification. The certification of centers for weaning in neurological and neurosurgical early rehabilitation is an important step towards defining neurorespiratory care and the role of the neurologist for intensive care and weaning in Germany. Thereby, the interdisciplinary dialogue between pneumologists, anesthesiologists, and neurologists is fostered. Also, the dialogue on treatment capacities and strategies with healthcare politicians, health insurances, and patient associations is facilitated.

Network properties and regional brain morphology of the insular cortex correlate with individual pain thresholds.

Pain thresholds vary considerably across individuals and are influenced by a number of behavioral, genetic and neurobiological factors. However, the neurobiological underpinnings that account for individual differences remain to be fully elucidated. In this study, we used voxel-based morphometry (VBM) and graph theory, specifically the local clustering coefficient (CC) based on resting-state connectivity, to identify brain regions, where regional gray matter volume and network properties predicted individual pain thresholds. As a main finding, we identified a cluster in the left posterior insular cortex (IC) reaching into the left parietal operculum, including the secondary somatosensory cortex, where both regional gray matter volume and the local CC correlated with individual pain thresholds. We also performed a resting-state functional connectivity analysis using the left posterior IC as seed region, demonstrating that connectivity to the pre- as well as postcentral gyrus bilaterally; that is, to the motor and primary sensory cortices were correlated with individual pain thresholds. To our knowledge, this is the first study that applied VBM in combination with voxel-based graph theory in the context of pain thresholds. The co-location of the VBM and the local CC cluster provide first evidence that both structure and function map to the same brain region while being correlated with the same behavioral measure; that is, pain thresholds. The study highlights the importance of the posterior IC, not only for pain perception in general, but also for the determination of individual pain thresholds.

Frequency and nature of pain in patients undergoing neurorehabilitation.

OBJECTIVE: This prospective study investigated the extent to which patients undergoing neurorehabilitation reported pain, how this pain developed during inpatient stay and whether patients were treated accordingly (using pain medication). METHODS: The extent of pain, performance in daily activities, with a focus on possible impairment from pain, and pain medication were assessed at the beginning and the end of neurorehabilitation treatment. Overall 584 patients, with various neurological diagnoses, such as stroke, intracerebral hemorrhage, polyneuropathy, etc. were classified into four groups based on whether they reported having "no pain," "mild pain," "moderate pain," or "severe pain." All patients received conventional neurorehabilitation therapy in the Mauritius Hospital, Germany. RESULTS: A total of 149 patients had clinically relevant pain at the beginning of their inpatient stay, at a group level this did not change significantly during the treatment period. At the end of inpatient stay, a slight increase was noted in patients reporting pain. Overall 164 patients suffered from moderate or severe pain, operationalized of pain scores >3 on the visual analog scale. A total of 145 patients who had pain at the end of inpatient stay, did not receive pain medication. There was a weak negative association between pain at baseline and activities of daily living at the end of the treatment period, such that, patients with higher pain levels tended to showed lower Barthel Index scores at the end. CONCLUSION: In our study, about one-third of patients suffered from clinically relevant pain during neurorehabilitation treatment and most of them did not receive any pain medication.

[Acute care interventions in inpatient neurorehabilitation]. / Krankenhausmedizinische Interventionen in der neurologischen Anschlussrehabilitation.

Treatment in hospitals differs from treatment in rehabilitation centers from a legal perspective because German law mandates that in hospitals physicians and other qualified personnel must be on duty at all times. This is not required for inpatient rehabilitation centers. Since this Act was passed more than 30 years ago, more acute medical interventions are now carried out and the number of older people in the population has increased. As a result patients are nowadays older, more multimorbid and therefore have a greater risk for medical complications. This is especially true for postacute neurological care. For this reason, the original legal framework for neurological rehabilitation treatment has become questionable. Therefore, we prospectively tested how often patients in inpatient neurorehabilitation suffer from complications that require immediate attention by qualified personnel. In 759 patients observed over a period of 6 months we found 602 complications requiring immediate interventions by physicians (e.g. falls, urinary tract infections, other forms of fever, diarrhea associated with Clostridium difficile, pneumonia, respiratory insufficiency, sepsis, epileptic seizures and arrhythmia). On average at least three acute care interventions occurred per day at the facility examined. We conclude that neurological inpatient rehabilitation has outgrown its legal foundations and now incorporates hospital care.

Cerebellar-hippocampal processing in passive perception of visuospatial change: An ego- and allocentric axis?

In addition to its role in visuospatial navigation and the generation of spatial representations, in recent years, the hippocampus has been proposed to support perceptual processes. This is especially the case where high-resolution details, in the form of fine-grained relationships between features such as angles between components of a visual scene, are involved. An unresolved question is how, in the visual domain, perspective-changes are differentiated from allocentric changes to these perceived feature relationships, both of which may be argued to involve the hippocampus. We conducted functional magnetic resonance imaging of the brain response (corroborated through separate event-related potential source-localization) in a passive visuospatial oddball-paradigm to examine to what extent the hippocampus and other brain regions process changes in perspective, or configuration of abstract, three-dimensional structures. We observed activation of the left superior parietal cortex during perspective shifts, and right anterior hippocampus in configuration-changes. Strikingly, we also found the cerebellum to differentiate between the two, in a way that appeared tightly coupled to hippocampal processing. These results point toward a relationship between the cerebellum and the hippocampus that occurs during perception of changes in visuospatial information that has previously only been reported with regard to visuospatial navigation.

Diffusion tensor imaging reveals changes in non-fat infiltrated muscles in late onset Pompe disease.

MRI is a helpful tool for monitoring disease progression in late-onset Pompe disease (LOPD). Our study aimed to evaluate if muscle diffusion tensor imaging (mDTI) shows alterations in muscles of LOPD patients with <10% fat-fraction. We evaluated 6 thigh and 7 calf muscles (both legs) of 18 LOPD and 29 healthy controls (HC) with muscle diffusion tensor imaging (mDTI), T1w, and mDixonquant sequences in a 3T MRI scanner. The quantitative mDTI-values axial diffusivity (λ1 ), mean diffusivity (MD), radial diffusivity (RD), and fractional anisotropy (FA) as well as fat-fraction were analyzed. 6-Minute Walk Test (6-MWT) data were correlated to diffusion metrics. We found that mDTI showed significant differences between LOPD and HC in diffusion parameters (P < .05). Thigh muscles with <10% fat-fraction showed significant differences in MD, RD, and λ1-3 . MD positively correlated with 6-MWT (P = .06). To conclude, mDTI reveals diffusion restrictions in muscles of LOPD with and without fat-infiltration and reflects structural changes prior to fatty degeneration.

Pain Perception, Brain Connectivity, and Neurochemistry in Healthy, Capsaicin-Sensitive Subjects.

Most of the occupational exposure limits (OELs) are based on local irritants. However, exposure to much lower concentrations of irritant substances can also lead to health complaints from workers. Exposure to irritants is often accompanied by strong unpleasant odors, and strong odors might have distracting effects and hence pose a safety risk. The findings obtained in human exposure studies with chemically sensitive, stressed, or anxious persons suggest that their ability to direct attention away from the odorous exposure and to focus on a cognitive task is reduced. In addition, after repeated odor exposure, these persons show signs of sensitization, i.e., difficulties in ignoring or getting used to the exposure. The question arises as to whether certain health conditions are accompanied by a change in sensitivity to odors and irritants, so that these persons are potentially more distracted by odors and irritants and therefore more challenged in working memory tasks than nonsusceptible persons. In our study, susceptible persons with sensory airway hyperreactivity ("capsaicin-sensitive") respond more strongly to mechanical skin stimuli than controls and show altered network connectivity. Capsaicin-sensitive subjects have a lower pain threshold and thus are more sensitive to mechanical skin stimuli. The intrinsic functional connectivity of their saliency network is higher, and the lower the GABAergic tone of the thalamus, the higher their pain sensitivity to mechanical stimuli. It seems that the increased communication between resting-state networks promotes a stronger perception of the sensory input signal. The results can be used to inform about actual risks (i.e., attention diversion and increased risk of accidents) and "pseudo" risks such as odor perception without a negative impact on one's well-being. This way, uncertainties that still prevail in the health assessment of odorous and sensory irritating chemicals could be reduced.

[Weaning in neurological and neurosurgical early rehabilitation-Results from the "WennFrüh" study of the German Society for Neurorehabilitation]. / Weaning in der neurologisch-neurochirurgischen Frührehabilitation ­ Ergebnisse der "WennFrüh"-Studie der Deutschen Gesellschaft für Neurorehabilitation.

Neurological and neurosurgical early rehabilitation patients are often so critically ill that they must be weaned from mechanical ventilation in addition to early rehabilitative treatment. The German Society for Neurorehabilitation (DGNR) carried out a survey and asked neurological weaning units to provide information on structural characteristics of the facility, including personnel and technical resources and the number of cases and outcome based on anonymous data. In total 36 weaning units from 11 federal states with a total of 496 beds participated in the survey. From 2516 weaning cases documented in 2019, 2097 (83.3%) could primarily be successfully weaned from mechanical ventilation and only 120 (4.8%) had to be discharged with home ventilation. The mortality in this sample was 11.0% (n = 276). The results of the survey demonstrate that prolonged weaning during early neurological and neurosurgical rehabilitation is an important and effective component of healthcare provision for critically ill patients in Germany.

Increased thalamic glutamate/glutamine levels in migraineurs.

BACKGROUND: Increased cortical excitability has been hypothesized to play a critical role in various neurological disorders, such as restless legs syndrome, epilepsy and migraine. Particularly for migraine, local hyperexcitability has been reported. Levels of regional excitatory and inhibitory neurotransmitters are related to cortical excitability and hence may play a role in the origin of the disease. Consequently, a mismatch of the excitatory-inhibitory neurotransmitter network might contribute to local hyperexcitability and the onset of migraine attacks. In this study we sought to assess local levels of glutamate / glutamine (GLX) and gamma-aminobutyric acid (GABA) in the occipital cortex and right thalamus of migraineurs and healthy subjects. METHODS: We measured interictally local biochemical concentrations in the occipital lobe and the right thalamus in patients with migraine (without aura) and healthy controls (HCs) using proton magnetic resonance spectroscopy at 3 T. GLX levels were acquired using PRESS and GABA levels using the GABA-sensitive editing sequence MEGA-PRESS. Regional GLX and GABA levels were compared between groups. RESULTS: Statistical analyses revealed significantly increased GLX levels in both the primary occipital cortex and thalamus. However, we found no group differences in GABA levels for these two regions. Correlation analyses within the migraine group revealed no significant correlations between pain intensity and levels of GLX or GABA in either of the two brain regions. CONCLUSIONS: Further research is needed to investigate the role of GABA/GLX ratios in greater depth and to measure changes in neurotransmitter levels over time, i.e. during migraine attacks and interictally.

Diffusion tensor imaging of the human calf: Variation of inter- and intramuscle-specific diffusion parameters.

PURPOSE: To investigate to what extent inter- and intramuscular variations of diffusion parameters of human calf muscles can be explained by age, gender, muscle location, and body mass index (BMI) in a specific age group (20-35 years). MATERIALS AND METHODS: Whole calf muscles of 18 healthy volunteers were evaluated. Magnetic resonance imaging (MRI) was performed using a 3T scanner and a 16-channel Torso XL coil. Diffusion-weighted images were acquired to perform fiber tractography and diffusion tensor imaging (DTI) analysis for each muscle of both legs. Fiber tractography was used to separate seven lower leg muscles. Associations between DTI parameters and confounds were evaluated. All muscles were additionally separated in seven identical segments along the z-axis to evaluate intramuscular differences in diffusion parameters. RESULTS: Fractional anisotropy (FA) and mean diffusivity (MD) were obtained for each muscle with low standard deviations (SDs) (SDFA : 0.01-0.02; SDMD : 0.07-0.14(10-3 )). We found significant differences in FA values of the tibialis anterior muscle (AT) and extensor digitorum longus (EDL) muscles between men and women for whole muscle FA (two-sample t-tests; AT: P = 0.0014; EDL: P = 0.0004). We showed significant intramuscular differences in diffusion parameters between adjacent segments in most calf muscles (P < 0.001). Whereas muscle insertions showed higher (SD 0.03-0.06) than muscle bellies (SD 0.01-0.03), no relationships between FA or MD with age or BMI were found. CONCLUSION: Inter- and intramuscular variations in diffusion parameters of the calf were shown, which are not related to age or BMI in this age group. Differences between muscle belly and insertion should be considered when interpreting datasets not including whole muscles. LEVEL OF EVIDENCE: 3 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2017;46:1137-1148.

Local GABA Concentration Predicts Perceptual Improvements After Repetitive Sensory Stimulation in Humans.

Learning mechanisms are based on synaptic plasticity processes. Numerous studies on synaptic plasticity suggest that the regulation of the inhibitory neurotransmitter γ-aminobutyric acid (GABA) plays a central role maintaining the delicate balance of inhibition and excitation. However, in humans, a link between learning outcome and GABA levels has not been shown so far. Using magnetic resonance spectroscopy of GABA prior to and after repetitive tactile stimulation, we show here that baseline GABA+ levels predict changes in perceptual outcome. Although no net changes in GABA+ are observed, the GABA+ concentration prior to intervention explains almost 60% of the variance in learning outcome. Our data suggest that behavioral effects can be predicted by baseline GABA+ levels, which provide new insights into the role of inhibitory mechanisms during perceptual learning.

Regionally Specific Regulation of Sensorimotor Network Connectivity Following Tactile Improvement.

Correlations between inherent, task-free low-frequency fluctuations in the blood oxygenation level-dependent (BOLD) signals of the brain provide a potent tool to delineate its functional architecture in terms of intrinsic functional connectivity (iFC). Still, it remains unclear how iFC is modulated during learning. We employed whole-brain resting-state magnetic resonance imaging prior to and after training-independent repetitive sensory stimulation (rSS), which is known to induce somatosensory cortical reorganization. We investigated which areas in the sensorimotor network are susceptible to neural plasticity (i.e., where changes in functional connectivity occurred) and where iFC might be indicative of enhanced tactile performance. We hypothesized iFC to increase in those brain regions primarily receiving the afferent tactile input. Strengthened intrinsic connectivity within the sensorimotor network after rSS was found not only in the postcentral gyrus contralateral to the stimulated hand, but also in associative brain regions, where iFC correlated positively with tactile performance or learning. We also observed that rSS led to attenuation of the network at higher cortical levels, which possibly promotes facilitation of tactile discrimination. We found that resting-state BOLD fluctuations are linked to behavioral performance and sensory learning, indicating that network fluctuations at rest are predictive of behavioral changes and neuroplasticity.

[Costs associated with multiresistant bacteria in neurorehabilitation]. / Mehrkosten durch multiresistente Erreger in der Neurorehabilitation.

BACKGROUND AND OBJECTIVES: The number of patients with multiresistant bacteria (MRB) in rehabilitation facilities is increasing. The increasing costs of hygienic isolation measures reduce resources available for core rehabilitation services. In addition to the existing lack of care, patients with MRB are at further risk of being given lower priority for admission to rehabilitation facilities. Therefore, the Hygiene Commission of the German Society for Neurorehabilitation (DGNR) attempted to quantify the overall risk for deterioration of rehabilitation care due to the financial burden of MRB. MATERIALS AND METHODS: To analyze the added costs associated with the rehabilitation of patients with MBR, the DGNR Hygiene Commission identified criteria for a cost assessment. Direct (consumables, personnel and miscellaneous costs) and indirect costs of loss of opportunity were evaluated in seven neurorehabilitation centers in different states across Germany. RESULTS: On average, hygienic isolation measures amounted to direct costs of 144 € per day (47 € consumables, 92 € personnel, 5 € for other costs such as extra transportation expenditure) and indirect costs of 274 €, totaling 418 € per patient with MRB per day. Given that approximately 10% of patients had MRB, the added costs of hygienic isolation measures equaled about one tenth of the overall budget of a rehabilitation center and can be expected to rise with the increasing numbers of patients with MRB. CONCLUSIONS: Admission of patients carrying MRB to neurorehabilitation centers triggers added costs that critically diminish the overall capacity for centers to provide their core rehabilitation services.