378 research outputs found
Red list and checklist of the limnic red algae and brown algae
Für Berlin wurden bisher sieben Arten limnischer Rotalgen (Rhodophyta) sicher nachgewiesen, davon sind zwei Bestandteil der Roten Liste. Diese Neufassung der Gesamtartenliste weist einige wesentliche Veränderungen gegenüber der Vorgängerliste auf, weil neben Zufallsfunden erstmalig auch mehrjährige Nachuntersuchungen von Rotalgenstandorten einbezogen werden konnten. Eine verschollene Rotalge wurde wiedergefunden, zwei Arten wurden im Untersuchungszeitraum erstmals nachgewiesen. Die Liste der limnischen Braunalgen (Phaeophyceae) enthält nach wie vor nur eine verschollene Art.The checklist of Berlin includes seven species of limnic red algae (Rhodophyta), two of them are part of the Red List. In comparison with the previous list now multi-annual findings are included besides single records. One extinct or missing species was found again and two species were discovered for the first time in Berlin. The list of limnic brown algae (Phaeophyceae) for Berlin still includes only one extinct species
Noisy Galvanic Stimulation Improves Roll-Tilt Vestibular Perception in Healthy Subjects
It has recently been demonstrated that noisy galvanic vestibular stimulation (nGVS) delivered as imperceptible white noise can improve balance control via the induction of stochastic resonance. However, it is unclear whether these balance improvements are accompanied by simultaneous enhancement to vestibular motion perception. In this study, 15 healthy subjects performed 8 quiet-stance tasks on foam with eyes closed at 8 different nGVS amplitudes ranging from 0 mA (baseline) to 0.5 mA. The nGVS amplitude that improved balance performance most compared to baseline was assigned as the optimal nGVS amplitude. Optimal nGVS amplitudes could be determined for 13 out of 15 subjects, who were included in the subsequent experimental procedures. The effect of nGVS delivered at the determined optimal intensity on vestibular perceptual thresholds was examined using direction-recognition tasks on a motion platform, testing roll rotations at 0.2, 0.5, and 1.0 Hz, both with active and sham nGVS stimulations. nGVS significantly reduced direction-recognition thresholds compared to the sham condition at 0.5 and 1.0 Hz, while no significant effect of nGVS was found at 0.2 Hz. Interestingly, no correlation was found between nGVS-induced improvements in balance control and vestibular motion perception at 0.5 and 1 Hz, which may suggest different mechanisms by which nGVS affects both modalities. For the first time, we show that nGVS can enhance roll vestibular motion perception. The outcomes of this study are likely to be relevant for the potential therapeutic use of nGVS in patients with balance problems
Robot-assisted gait training to reduce pusher behavior
Objective To determine the effects of 2 weeks of intensive robot-assisted gait training (RAGT) on pusher behavior compared to nonrobotic physiotherapy (nR-PT). Methods In a single-blind, randomized, controlled trial with 2 parallel arms, we compared 2 weeks of daily RAGT (intervention group) with the same amount of nR-PT (control group). Patients with subacute stroke who had pusher behavior according to the Scale for Contraversive Pushing (SCP) were included. The primary research questions were whether changes in pusher behavior would differ between groups post intervention, and at a follow-up 2 weeks afterward (SCP and Burke Lateropulsion Scale, Class II evidence). Secondary outcomes included the Performance-Oriented Mobility Assessment, the Functional Ambulation Classification, and the Subjective Visual Vertical. Results Thirty-eight patients were randomized. Thereof, 30 patients received the allocated intervention and were included in the analyses. RAGT led to a larger reduction of pusher behavior than nR-PT at post test (SCP: U = 69.00, r = -0.33, p = 0.037;Burke Lateropulsion Scale: U = 47.500, r = -0.50, p = 0.003) and at follow-up (SCP: U = 54.00, r = -0.44, p = 0.008). Pusher behavior had ceased in 6 of 15 participants in the intervention group and 1 of 15 participants in the control group at post test. At follow-up, 9 of 15 and 5 of 15 participants, respectively, no longer exhibited the behavior. Conclusions Two weeks of RAGT seems to persistently reduce pusher behavior, possibly by recalibrating the disturbed inner reference of verticality. The potential benefits of RAGT on pusher behavior and verticality perception require further investigation. Trial registration German Clinical Trials Register (registration number: DRKS00003444). Classification of evidence This study provides Class II evidence that RAGT is beneficial to reduce pusher behavior in patients with stroke
Follow-up of vestibular function in bilateral vestibulopathy
Objective: Bilateral vestibulopathy (BV) leads to a bilateral deficit of the vestibulo-ocular reflex and has various aetiologies. The main goal of this study was to determine the frequency and degree of recovery or worsening of vestibular function over time.Methods: 82 patients (59 males, 23 females; mean age at the time of diagnosis 56.3 (SD 17.6) years) were re-examined 51 (36) months after the first examination. All patients underwent a standardised neuro-ophthalmological and neuro-otological examination. Electronystagmography with bithermal caloric irrigation was analysed by measurement of the mean peak slow phase velocity (SPV) of the induced nystagmus. Patients evaluated the course of their disease in terms of balance, gait unsteadiness and health related quality of life.Results: Statistical analysis of the mean peak SPV of caloric induced nystagmus revealed a non-significant worsening over time (initial mean peak SPV 3.0 (3.5)°/s vs 2.1 (2.8)°/s). With respect to subgroups of aetiology, only patients with BV due to meningitis exhibited an increasing, but non-significant SPV (1.0 (1.4)°/s vs 1.9 (1.6)°/s). Vestibular outcome was independent of age, gender, time course of manifestation and severity of BV. Single analysis of all patients showed that a substantial improvement ⩾5°/s occurred in two patients on both sides (idiopathic n = 1, Sjögren's syndrome n = 1) and in eight patients on one side (idiopathic n = 6, meningitis n = 1, Menière's disease n = 1). In 84% of patients there was impairment of their health related quality of life (42% slight, 24% moderate, 18% severe). Forty-three per cent of patients rated the course of their disease as stable, 28% as worsened and 29% as improved.Conclusions: Our data support the view that more than 80% of patients with BV do not improve. Thus the prognosis of BV is less favourable than assumed
No evidence for after-effects of noisy galvanic vestibular stimulation on motion perception
Noisy galvanic vestibular stimulation (nGVS) delivered at imperceptible intensities can improve vestibular function in health and disease. Here we evaluated whether nGVS effects on vestibular function are only present during active stimulation or may exhibit relevant post-stimulation after-effects. Initially, nGVS amplitudes that optimally improve posture were determined in 13 healthy subjects. Subsequently, effects of optimal nGVS amplitudes on vestibular roll-tilt direction recognition thresholds (DRT) were examined during active and sham nGVS. Ten of 13 subjects exhibited reduced DRTs during active nGVS compared to sham stimulation (p < 0.001). These 10 participants were then administered to 30 mins of active nGVS treatment while being allowed to move freely. Immediately post-treatment, DRTs were increased again (p = 0.044), reverting to baseline threshold levels (i.e. were comparable to the sham nGVS thresholds), and remained stable in a follow-up assessment after 30 min. After three weeks, participants returned for a follow-up experiment to control for learning effects, in which DRTs were measured during and immediately after 30 min application of sham nGVS. DRTs during both assessments did not differ from baseline level. These findings indicate that nGVS does not induce distinct post-stimulation effects on vestibular motion perception and favor the development of a wearable technology that continuously delivers nGVS to patients in order to enhance vestibular function
Mechanisms underlying treatment effects of vestibular noise stimulation on postural instability in patients with bilateral vestibulopathy
Calretinin as a Marker for Premotor Neurons Involved in Upgaze in Human Brainstem
Eye movements are generated by different premotor pathways. Damage to them can cause specific deficits of eye movements, such as saccades. For correlative clinico-anatomical post-mortem studies of cases with eye movement disorders it is essential to identify the functional cell groups of the oculomotor system in the human brain by marker proteins. Based on monkey studies, the premotor neurons of the saccadic system can be identified by the histochemical markers parvalbumin (PAV) and perineuronal nets in humans. These areas involve the interstitial nucleus of Cajal (INC) and the rostral interstitial nucleus of the medial longitudinal fascicle (RIMLF),which both contain premotor neurons for upgaze and downgaze. Recent monkey and human studies revealed a selective excitatory calretinin (CR)-positive input to the motoneurons mediating upgaze, but not to those for downgaze. Three premotor regions were identified as sources of CR input in monkey: y-group, INC and RIMLF. These findings suggest that the expression pattern of parvalbumin and CR may help to identify premotor neurons involved in up- or downgaze. In a postmortem study of five human cases without neurological diseases we investigated the y-group, INC and RIMLF for the presence of parvalbumin and CR positive neurons including their co-expression. Adjacent thin paraffin sections were stained for the aggrecan (ACAN) component of perineuronal nets, parvalbumin or CR and glutamate decarboxylase. The comparative analysis of scanned thin sections of INC and RIMLF revealed medium-sized parvalbumin positive neurons with and without CR coexpression, which were intermingled. The parvalbumin/CR positive neurons in both nuclei are considered as excitatory premotor upgaze neurons
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