Background and Purpose: Rapid access to acute stroke treatment improves clinical outcomes in patients with ischemic stroke. We aimed to shorten the time to admission and to acute stroke treatment for patients with acute stroke in the Hamburg metropolitan area by collaborative multilevel measures involving all hospitals with stroke units, the Emergency Medical Services (EMS), and health-care authorities. Methods: In 2007, an area-wide stroke care quality project was initiated. The project included mandatory admission of all stroke patients in Hamburg exclusively to hospitals with stroke units, harmonized acute treatment algorithms among all hospitals, repeated training of the EMS staff, a multimedia educational campaign, and a mandatory stroke care quality monitoring system based on structured data assessment and quality indicators for procedural measures. We analyzed data of all patients with acute stroke who received inhospital treatment in the city of Hamburg during the evaluation period from the quality assurance database data and evaluated trends of key quality indicators over time. Results: From 2007 to 2016, a total of 83,395 patients with acute stroke were registered. During this period, the proportion of patients admitted within ≤3 h from symptom onset increased over time from 27.8% in 2007 to 35.2% in 2016 (p < 0.001). The proportion of patients who received rapid thrombolysis (within ≤30 min after admission) increased from 7.7 to 54.1% (p < 0.001). Conclusions: Collaborative stroke care quality projects are suitable and effective to improve acute stroke care.

Die neurologische Frührehabilitation nach Schlaganfall ist ein wesentlicher Faktor, um den Behinderungsgrad langfristig zu senken. Je früher die rehabilitative Behandlung von Schlaganfallpatienten einsetzt, desto besser ist das funktionelle Outcome. Mit einem eigens entwickelten Erhebungsinstrument wurden Daten von 333 Schlaganfallpatienten in 3 Hamburger Frührehabilitationseinrichtungen über 20 Monate gesammelt und deskriptiv analysiert. Es ergaben sich unterschiedliche Rückbildungstendenzen der verschiedenen Symptome, einen nicht unerheblichen Anteil an Komplikationen und eine relativ hohe Rate an weiterführenden stationären rehabilitativen Maßnahmen. Die entwickelten Qualitätsindikatoren decken die relevanten Aspekte der Rehabilitation mit wenigen Kennzahlen ab. Aus den erhobenen Daten lässt sich ein Qualitätsmanagement-System entwickeln, um die Behandlungsqualität weiter zu verbessern.

In the anterior circulation, the hyperdense middle cerebral artery sign (HMCAS) is a well established marker for early ischemia. Similarly, the hyperdense basilar artery sign may be a diagnostic clue for basilar artery thrombosis. Other hyperdense artery signs have not yet been described. The purpose of this study was to define the hyperdense posterior cerebral artery sign (HPCAS) and determine its incidence, diagnostic value, and reliability as a marker for ischemia in the territory of the posterior cerebral artery (PCA).

The enhancement of cognitive function in healthy subjects by medication, training or intervention yields increasing political, social and ethical attention. In this paper facilitatory effects of single-pulse TMS and repetitive TMS on a simple picture naming task are presented. A significant shortening of picture naming latencies was observed after single-pulse TMS over Wernicke's area. The accuracy of the response was not affected by this speed effect. After TMS over the dominant motor cortex or over the non-dominant temporal lobe, however, no facilitation of picture naming was observed. In the rTMS experiments only rTMS of Wernicke's area had an impact on picture naming latencies resulting in a shortening of naming latencies without affecting the accuracy of the response. rTMS over the visual cortex, Broca's area or over the corresponding sites in the non-dominant hemisphere had no effect. Single-pulse TMS is able to facilitate lexical processes due to a general preactivation of language-related neuronal networks when delivered over Wernicke's area. Repetitive transcranial magnetic stimulation over Wernicke's area also leads to a brief facilitation of picture naming possibly by shortening linguistic processing time. Whether TMS or rTMS can be used to aid linguistic therapy in the rehabilitation phase of aphasic patients should be subject of further investigations.

We used single-pulse transcranial magnetic stimulation (TMS) to study visuospatial attention. TMS was applied over one hemisphere, or simultaneously over both the right and left posterior parietal cortex (PPC), at two different interstimulus intervals (ISI) during a visual detection task. Unilateral TMS over the right and left PPC, respectively, impaired detection of contralateral presented visual stimuli at an ISI of 150 ms. By contrast, simultaneous biparietal TMS induced no significant changes in correct stimulus detection. TMS at an ISI of 250 ms evoked no changes for magnetic stimulation over either the right or the left parietal cortex. These results suggest that both PPC play a crucial role at a relatively early stage in the widely distributed brain network of visuospatial attention. The abolition of behavioral deficits during simultaneous biparietal TMS underlines the common hypothesis that an interhemispheric imbalance might underlie the disorders of neglect and extinction seen following unilateral brain damage.

Repetition priming denotes a behavioural change caused by prior exposure to a stimulus. The effect is known to last for weeks. This study addresses the underlying neural mechanisms for very-long-term picture priming by using event-related functional magnetic resonance imaging complemented by a behavioural paradigm. Previous functional imaging studies with shorter retention intervals have shown that priming is associated with changes in the activity of both the occipital and posterior temporal cortex. In this study we compared retention intervals of 1 day and 6 weeks after initial exposure to a picture stimulus. Priming-related decreases in cortical activity in posterior extrastriate and dorsal left inferior frontal areas were found only for the shorter retention interval. In contrast, fMRI activation in the inferior posterior temporal and anterior left inferior frontal cortex was reduced following priming for both retention intervals. In the behavioural paradigm, the priming effect was stable over time. We conclude that the left inferior frontal and inferior posterior temporal cortex play a key role in the very-long-term priming effect.

Motor practice induces plastic changes within the cortical motor system. Whereas rapidly evolving changes of cortical motor representations were the subject of a number of recent studies, effects of long‐term practice on the motor system are so far poorly understood. In the present study pianists and nonmusicians were investigated using functional magnetic resonance imaging. Both groups performed simple and complex movement sequences on a keyboard with the right hand, the tasks requiring different levels of ordinal complexity. The aim of this study was to characterize motor representations related to sequence complexity and to long‐term motor practice. In nonmusicians, complex motor sequences showed higher fMRI activations of the presupplementary motor area (pre‐SMA) and the rostral part of the dorsal premotor cortex (PMd) compared to simple motor sequences, whereas musicians showed no differential activations. These results may reflect the higher level of visuomotor integration required in the complex task in nonmusicians, whereas in musicians this rostral premotor network was employed during both tasks. Comparison of subject groups revealed increased activation of a more caudal premotor network in nonmusicians comprising the caudal part of the PMd and the supplementary motor area. This supports recent results suggesting a specialization within PMd. Furthermore, we conclude that plasticity due to long‐term practice mainly occurs in caudal motor areas directly related to motor execution. The slowly evolving changes in M1 during motor skill learning may extend to adjacent areas, leading to more effective motor representations in pianists. Hum Brain Mapp, 2005. © 2005 Wiley‐Liss, Inc.

Die Erstellung einer internen Repräsentation des uns umgebenden Raums ist eine komplexe kortikale Funktion an der parietale, frontaler und temporaler Areale beteiligt sind. Zur Untersuchung der Funktionsweise dieses Netzwerkes wurde die Kombination von funktioneller Kernspintomographie (fMRI) und Transkranieller Magnetstimulation (TMS) eingesetzt.

Ergebnisse aktueller Studien deuten auf eine funktionelle Verbindung zwischen linkshemisphärischen Spracharealen und Regionen für die Handmotorik hin.Ihre Bedeutung ist unklar, möglicherweise ist Gestik ein Korrelat auf Verhaltensebene. In den im folgenden beschriebenen Experimenten wurde funktionelle Kernspintomographie (fMRI) und transkranielle Magnetstimulation (TMS) verwendet, um die funktionelle Beziehung zwischen Sprache und Handmotorik genauer zu charakterisieren.

Reading of musical notes and playing piano is a very complex motor task which requires years of practice. In addition to motor skills, rapid and effective visuomotor transformation as well as processing of the different components of music like pitch, rhythm and musical texture are involved. The aim of the present study was the investigation of the cortical network which mediates music performance compared to music imagery in 12 music academy students playing the right hand part of a Bartok piece using functional magnetic resonance imaging (fMRI). In both conditions, fMRI activations of a bilateral frontoparietal network comprising the premotor areas, the precuneus and the medial part of Brodmann Area 40 were found. During music performance but not during imagery the contralateral primary motor cortex and posterior parietal cortex (PPC) bilaterally was active. This reflects the role of primary motor cortex for motor execution but not imagery and the higher visuomotor integration requirements during music performance compared to simulation. The notion that the same areas are involved in visuomotor transformation/motor planning and music processing emphasizes the multimodal properties of cortical areas involved in music and motor imagery in musicians.

The processing of auditory spatial information in cortical areas of the human brain outside of the primary auditory cortex remains poorly understood. Here we investigated the role of the superior temporal gyrus (STG) and the occipital cortex (OC) in spatial hearing using repetitive transcranial magnetic stimulation (rTMS). The right STG is known to be of crucial importance for visual spatial awareness, and has been suggested to be involved in auditory spatial perception. We found that rTMS of the right STG induced a systematic error in the perception of interaural time differences (a primary cue for sound localization in the azimuthal plane). This is in accordance with the recent view, based on both neurophysio-logical data obtained in monkeys and human neuroimaging studies, that information on sound location is processed within a dorsolateral “where” stream including the caudal STG. A similar, but opposite, auditory shift was obtained after rTMS of secondary visual areas of the right OC. Processing of auditory information in the OC has previously been shown to exist only in blind persons. Thus, the latter finding provides the first evidence of an involvement of the visual cortex in spatial hearing in sighted human subjects, and suggests a close interconnection of the neural representation of auditory and visual space. Because rTMS induced systematic shifts in auditory lateralization, but not a general deterioration, we propose that rTMS of STG or OC specifically affected neuronal circuits transforming auditory spatial coordinates in order to maintain alignment with vision.

Introduction: Manual gestures are believed to denote an early step during the evolution of language preceding vocalisation. According to this theory development of the so-called mirror neuron system which is active in the brain during observation and execution of an action was a necessary prerequisite of the emergence of human communication. If so, cortical systems for dominant hand use and language may be closely connected.Using functional magnetíc resonance imaging, the present study tested whether there are functional interaction between the cortical systems for planning and execution of hand movements and linguistic processing.

Electrophysiological studies have shown that forceful activation of the hand muscles (power grip) is accompanied by an increased excitability of the ipsilateral corticospinal system. This increase in excitability may be due to spinal or cortical mechanisms. Here we show with fMRI that this phenomenon is at least in part mediated at a cortical level. We used TMS to show that the increased ipsilateral excitability during a forceful maneuver leads to enhanced stimulus-response curves. fMRI was used to compare the activation during a repetitive hand movement with or without an accompanying power grip on the opposite site. The power grip reduced movement-related activation in the ipsilateral sensorimotor cortex. Peak deactivation was located in the left postcentral gyrus extending into the adjacent precentral gyrus. This finding suggests that a forceful activation of the hand muscles disinhibits a distinct functional representation in the ipsilateral sensorimotor cortex. Consequently, the excitability of the corticospinal system increases and less neuronal excitatory activity is needed to perform a given task. The results may be important for a variety of studies as they suggest that fMRI may show decreased hemodynamic response under conditions in which other neurophysiological methods have shown increased functional activity.

Benennen von bereits zuvor einmal präsentierten Bildern führt zu einer Verkürzung der Benennlatenz im Vergleich zum Benennen von bislang unbekannten Bildstimuli. Als Korrelat dieses sogenannten Priming-Effekts findet sich in Studien mit funktioneller Bildgebung eine Reduktion der zur Bildbenennung erforderlichen Aktivierung; eine wesentliche Rolle scheint hierbei der inferiore temporale Kortex (Brodmann Areal 37 (BA37)) zu spielen. Zudem konnte gezeigt werden, dass repetitive transkranielle Magnetstimulation über dem linken inferioren temporalen Kortex die Benennlatenz von Bildern verlängert. In dieser Studie untersuchten wir die funktionelle Relevanz des linken inferioren temporalen Kortex für den Langzeit-Priming-Effekt bei Bildbenennung. Zehn Probanden führten zunächst eine Benennung von zwei Sets von Bildstimuli durch, die Gegenstände des täglichen Lebens zeigten. Ein Set wurde ohne TMS benannt, das andere Set, nachdem 1Hz TMS über dem linken BA 37 appliziert worden war. Drei Tage später wurden in einer funktionellen MRI-Untersuchung erneut die beiden Sets benannt. Es zeigte sich eine deutlich reduzierte fMRI-Aktivierung im inferioren temporalen Kortex beidseits für die Benennung von bekannten Stimuli ohne repetitive TMS im Vergleich zu Stimuli, die nach repetitiver TMS über dem linken BA 37 benannt wurden. Dieses Muster reduzierter fMRI-Aktivierung ist für den Priming-Effekt bei Bildbenennung vorbeschrieben. Wir nehmen an, dass der Priming-Effekt bei wiederholter Stimuluspräsentation durch die Beeinflussung der Bildbenennung mit repetitiver transkranieller Magnetstimulation reduziert wurde. Wir folgern, dass der inferiore temporale Kortex eine funktionelle Relevanz für den Langzeit-Priming-Effekt bei Bildbenennung hat.

Recently a growing body of evidence has suggested that a functional link exists between the hand motor area of the language dominant hemisphere and the regions subserving language processing. We examined the excitability of the hand motor area and the leg motor area during reading aloud and during non-verbal oral movements using transcranial magnetic stimulation (TMS). During reading aloud, but not before or afterwards, excitability was increased in the hand motor area of the dominant hemisphere. This reading effect was found to be independent of the duration of speech. No such effect could be found in the contralateral hemisphere. The excitability of the leg area of the motor cortex remained unchanged during reading aloud. The excitability during non-verbal oral movements was slightly increased in both hemispheres. Our results are consistent with previous findings and may indicate a specific functional connection between the hand motor area and the cortical language network.

OBJECTIVE:Neuroimaging studies have suggested an evolution of the brain activation pattern in the course of motor recovery after stroke. Initially poor motor performance is correlated with an recruitment of the uninjured hemisphere that continuously vanished until a nearly normal (contralateral) activation pattern is achieved and motor performance is good. Here we were interested in the early brain activation pattern in patients who showed a good and rapid recovery after stroke. METHODS:Ten patients with first-ever ischemic stroke affecting motor areas had to perform self-paced simple or more complex movements with the affected or the unaffected hand during functional magnetic resonance imaging (fMRI). The location and number of activated voxels above threshold were determined. To study possible changes in the cortical motor output map the amplitude of the motor evoked potentials (MEP) and the extent of the excitable area were determined using transcranial magnetic stimulation (TMS). RESULTS:The pattern of activation observed with movements of the affected and the unaffected hand was similar. In the simple motor task significant (P<0.05) increases were found in the primary motor cortex ipsilateral to the movement, the supplementary motor area and the cerebellar hemisphere contralateral to the movement during performance with the affected hand compared to movements with the unaffected hand. When comparing simple with more complex movements performed with either the affected or the unaffected hand, a further tendency to increased activation in motor areas was observed. The amplitude of MEPs obtained from the affected hemisphere was smaller and the extent of cortical output maps was decreased compared to the unaffected hemisphere; but none of the patients showed MEPs at the affected hand when the ipsilateral unaffected motor cortex was stimulated. CONCLUSIONS:Despite a rapid and nearly complete motor recovery the brain activation pattern was associated with increased activity in (bilateral) motor areas as revealed with fMRI. TMS revealed impaired motor output properties, but failed to demonstrate ipsilateral motor pathways. Successful recovery in our patients may therefore rely on the increased bilateral activation of existing motor networks spared by the injury.