Intravenous levetiracetam in clinical practice--Results from an independent registry

PURPOSE

Most common clinical studies with antiepileptic drugs do not reflect medical everyday practice due to their strict in- and exclusion criteria and specifications of treatment regimens. Here we present a large non-interventional registry with the intention to evaluate the spectrum of applications in daily use and the efficacy and tolerability of intravenously given levetiracetam (LEV-iv).

METHODS

In a prospective approach of 17 neurological and neuropediatric centres in Germany LEV-iv treated patients of all ages were included over a period of 10 months. The observational period was 10 days with daily documentation of LEV-iv administration, type and frequency of seizures, currently used drugs and doses, and adverse events (AEs). In addition, treatment efficacy and tolerability were assessed by patients and physicians at study end as well as practicability of LEV-iv using a five-step scale.

RESULTS

In 95 patients LEV-iv was administered, 93 were included into the analysis. The median LEV-iv dose was 1500 mg (range 110-6000 mg) per day. Median age was 66 years (range 0.7-90.3 years). The majority of patients (n=70, 75%) suffered from status epilepticus (SE, n=55, 59%) and acute seizure clusters (n=15, 16%). Of those with SE, 41 patients (75%) had SE for the first time. Acute seizure clusters and SE terminated in 83% after LEV-iv administration. A total of 29 adverse events were reported in 17 of the 95 patients from the safety set. Ten of these were at least possibly related to LEV-iv treatment. Slight decrease of blood pressure during the infusion (3 patients each) was captured most frequently. No serious side effect was observed. Physicians rated the efficacy and tolerability of LEV-iv treatment as good or very good in 78% and 82% of the cases, respectively.

CONCLUSION

In this large observational study of everyday practise the use of LEV-iv exhibited a remarkable good response and tolerability in patients with acute onset seizures (mostly SE). Further randomized controlled studies, like the established status epilepticus trial (ESET) are needed to confirm these findings.

Peripheral blood levels of matrix metalloproteinase-9 predict lesion volume in acute stroke

Matrix metalloproteinases (MMPs) have been implicated to play an important role in the destruction of the extracellular matrix in diseases of the central nervous system. This study investigated whether the expression of one of these proteases, MMP-9 in blood, is related to the size of human brain infarcts assessed with magnetic resonance imaging. Consecutively, twenty-one acute stroke patients were included prospectively into our study. In blood samples drawn within 24 h after onset, MMP-9 RNA-expression and proteolytic-activity were analyzed by quantitative polymerase chain reaction and gelatin zymography, respectively. The ischemic lesion volumes in time to peak perfusion maps and diffusion weighted imaging were measured morphometrically. RNA-expression levels of MMP-9 in peripheral blood mononuclear cells (PBMCs) correlated with the brain infarct lesion (TTP-delay 4 s, r = -0.61, p = 0.007; TTP-delay 6 s: r = -0.58, p = 0.012; DWI r = -0.47; p = 0.047). Our preliminary results demonstrate that MMP-9 RNA is upregulated in PBMCs in proportion to ischemia. These findings suggest that MMP-9 might contribute to the manifestation of ischemic brain damage. Since MMP-9 is upregulated in acute ischemia inhibition of MMP-9 may represent a complementary treatment target in acute stroke therapy.

Clinical impact of MRI perfusion disturbances and normal diffusion in acute stroke patients

PURPOSE

In acute ischemic stroke MR-imaging typically shows diffusion abnormalities surrounded by reduced perfusion signifying the so-called ischemic penumbra. Mismatch between diffusion and perfusion abnormalities gives indication for thrombolysis. But is there an indication for thrombolytic treatment, if there is no diffusion abnormality but pathologic perfusion combined with acute stroke symptoms?.

MATERIAL AND METHODS

MR-imaging of 1465 patients treated on our Stroke Unit between June 2004 and May 2007 retrospectively are analyzed. 6 patients met the inclusion criteria of severe neurological symptoms, large territorial perfusion disturbances, lack of diffusion abnormalities and complete neurological recovery after treatment.

RESULTS

In all six patients MTT measurements showed a significantly depressed perfusion in the symptomatic hemisphere (p<0.02). Time-to-peak delay correlated with the mean transit time delay (0.949, p<0.01). Indication for thrombolysis was based on perfusion abnormalities and clinical symptoms. Stroke symptoms could be reversed in all patients without any complication.

CONCLUSION

Whereas diffusion imaging could not reveal any abnormality, perfusion analysis legitimated therapy with systemic thrombolysis in heavily affected patients. This work underlines the importance of multimodal MR imaging for guiding treatment decisions in acute stroke patients.

Asymptomatic motor cortex displacement due to a giant arachnoid cyst

Cerebral lesions are held to induce plastic changes of the brain. Less well established, however, is how much space-occupying brain lesions may only displace functional representations. In a 66-year-old man we show, by means of functional magnetic resonance imaging and transcranial magnetic stimulation, a profound displacement of the motor cortex due to a large asymptomatic arachnoid cyst. Thus, the chronically compressed brain is capable of sustaining normal brain function without utilizing the potential of cortical plasticity.

Positron emission tomography studies of the somatosensory system in man

Activity in the human somatosensory system was measured by regional cerebral blood flow (rCBF) and by the binding of [11C]nimodipine to L-type Ca2+ channels. These physiological variables were considered to be indicators of neuronal and synaptic activity. In general, structures in the cerebellum, thalamus and the somatosensory cortices which increased their rCBF in response to somatosensory stimulation also showed high binding of [11C]nimodipine. Voluntary movements carried out largely independently of sensory feedback, natural somatosensory stimulation and passive stimulation of the somatosensory system all activate the somatosensory system. However, it is possible by subtraction techniques to show that differences in activations between these conditions exist in the cerebellum and the somatosensory cortices in the anterior part of the parietal lobe.

Different cortical activations during visuospatial attention and the intention to perform a saccade

Everyday life often necessitates dissociation between our directed attention and the intention to direct our gaze. Accordingly, the differential role of visual and motor related areas in the one or the other process is an issue of an ongoing debate. Here we used functional magnetic resonance imaging to elaborate a differentiation between visuospatial attention and the intention for a horizontal saccade in these cortical areas. Subjects fixated a central target, while they directed their attention to a colored cue in the left or right visual field. Regardless of its location, the color of the cue instructed the direction of the upcoming saccade (intention). The attention to the peripheral cue and the intention to perform the saccade were thus either directed to the same side or to opposite sides. A random effects analysis of the imaging data showed that activation of the early visual cortex and the motion sensitive complex was biased by attention to the contralateral cue, whereas activity of the color sensitive complex was modulated by the stimulus instructing a contraversive saccade. The posterior parietal cortex and the proper supplementary eye field (SEF) were most strongly activated in case of spatially congruent attention and intention. In contrast, activity of the pre-SEF and the frontal eye field was enhanced by spatially divergent attention and intention. The results presented here advance our understanding of how the human brain processes spatial information. Noteworthy, the visuomotor related areas show a subtle cortical separation for visual related attention and saccade related intention.

Visual cortex activation in kinesthetic guidance of reaching

The purpose of this research was to determine the cortical circuit involved in encoding and controlling kinesthetically guided reaching movements. We used (15)O-butanol positron emission tomography in ten blindfolded able-bodied volunteers in a factorial experiment in which arm (left/right) used to encode target location and to reach back to the remembered location and hemispace of target location (left/right side of midsagittal plane) varied systematically. During encoding of a target the experimenter guided the hand to touch the index fingertip to an external target and then returned the hand to the start location. After a short delay the subject voluntarily moved the same hand back to the remembered target location. SPM99 analysis of the PET data contrasting left versus right hand reaching showed increased (P < 0.05, corrected) neural activity in the sensorimotor cortex, premotor cortex and posterior parietal lobule (PPL) contralateral to the moving hand. Additional neural activation was observed in prefrontal cortex and visual association areas of occipital and parietal lobes contralateral and ipsilateral to the reaching hand. There was no statistically significant effect of target location in left versus right hemispace nor was there an interaction of hand and hemispace effects. Structural equation modeling showed that parietal lobe visual association areas contributed to kinesthetic processing by both hands but occipital lobe visual areas contributed only during dominant hand kinesthetic processing. This visual processing may also involve visualization of kinesthetically guided target location and use of the same network employed to guide reaches to visual targets when reaching to kinesthetic targets. The present work clearly demonstrates a network for kinesthetic processing that includes higher visual processing areas in the PPL for both upper limbs and processing in occipital lobe visual areas for the dominant limb.

EFNS guideline on neuroimaging in acute stroke. Report of an EFNS task force

Neuroimaging techniques are necessary for the evaluation of stroke, one of the leading causes of death and neurological impairment in developed countries. The multiplicity of techniques available has increased the complexity of decision making for physicians. We performed a comprehensive review of the literature in English for the period 1965-2005 and critically assessed the relevant publications. The members of the panel reviewed and corrected an initial draft, until a consensus was reached on recommendations stratified according to the European Federation of Neurological Societies (EFNS) criteria. Non-contrast computed tomography (CT) scan is the established imaging procedure for the initial evaluation of stroke patients. However, magnetic resonance imaging (MRI) has a higher sensitivity than CT for the demonstration of infarcted or ischemic areas and depicts well acute and chronic intracerebral hemorrhage. Perfusion and diffusion MRI together with MR angiography (MRA) are very helpful for the acute evaluation of patients with ischemic stroke. MRI and MRA are the recommended techniques for screening cerebral aneurysms and for the diagnosis of cerebral venous thrombosis and arterial dissection. For the non-invasive study of extracranial vessels, MRA is less portable and more expensive than ultrasonography but it has higher sensitivity and specificity for carotid stenosis. Transcranial Doppler is very useful for monitoring arterial reperfusion after thrombolysis, for the diagnosis of intracranial stenosis and of right-to-left shunts, and for monitoring vasospasm after subarachnoid hemorrhage. Currently, single photon emission computed tomography and positron emission tomography have a more limited role in the evaluation of the acute stroke patient.

Quantitative Assessment of Recovery from Motor Hemineglect in Acute Stroke Patients

BACKGROUND AND PURPOSE

Motor hemineglect is characterized by an underutilization of one side of the body. It is a higher-order motor disorder that resembles hemiplegia although being substantially different from it due to a preserved motor output system. Its role for poststroke recovery is still unclear.

METHODS

We studied 52 patients presenting with acute hemiparetic stroke over the first 7 days after symptom onset. Nineteen patients had unilateral motor hemineglect. Impairment was clinically assessed with the European Stroke Scale and a multifactorial motor score. It was further assessed quantitatively, as overall arm activity was measured continuously by Actiwatches. Lesion volumes were measured morphometrically within 24 h on perfusion- and diffusion-weighted magnetic resonance images and on average on day 9 by T2-weighted magnetic resonance imaging.

RESULTS

Patients with motor hemineglect were characterized by significantly reduced initial arm activity in comparison to patients without motor hemineglect. This was paralleled by larger brain lesions in the patients with motor hemineglect. Patients with motor neglect either recovered virtually completely (5 cases; 2/5 left hemisphere; 3/5 treated with recombinant tissue plasminogen activator, rt-PA) within 7 days or did not improve at all (14 cases; 3/14 left hemisphere; 3/14 rt-PA treated).

CONCLUSION

Our data reveal a high incidence of motor hemineglect in patients with acute stroke. They further show that these patients are more severely compromised than those without motor hemineglect. A rapid and near complete recovery was observed in about one fourth of the motor hemineglect patients and may be related to involvement of the left hemisphere or to therapy with thrombolysis.

Cingulate cortex activation and competing responses: the role of preparedness for competition

Regional cerebral blood flow (rCBF) was studied in a task, where a preparatory stimulus (S1) cued for an imperative second stimulus (S2) which was associated with a response. Two preparatory stimuli cued unequivocally each for one response. In contrast, a third preparatory stimulus cued for two response alternatives which appeared for the same ratio (each in 50% of all trials) introducing response competition. In a first experimental condition, non-arbitrary, unambiguous stimuli were used as S1 to enable the subjects to prepare their responses. In a second and third scan, arbitrary preparatory stimuli were used during different stages of awareness for the S1-S2 association. Subjects performed this task "naive" without knowledge about the S1-S2 association and also in an experimental condition being aware of the S1-S2 association. Button presses after unambiguous, non-arbitrary preparatory stimuli activated the right middle frontal gyrus and inferior parietal lobe if S1 was associated with a definite response. When the subjects did not know the S1-S2 relation, left prefrontal cortex activation was associated with trials including definite responses. Performing the same S1-S2 response condition after subjects knew their relation right prefrontal and left parietal areas became additionally engaged. However, in the first experimental condition using unambiguous, non-arbitrary stimuli and in the third, "aware" experimental condition when S1 was coupled with two response alternatives, the anterior cingulate cortex was activated. As these experimental conditions have in common, that the preparatory stimulus shares information about the upcoming competing response alternatives they highlight the evaluative role of the anterior cingulate cortex for competing actions.

Reorganization of cerebral circuits in human brain lesion

Recovery after focal brain lesions is supposed to be mediated by cerebral reorganization. Stroke is a powerful model to study these processes in the human brain, since middle cerebral artery infarction is a common neurological disease with a clearly defined onset of a lateralized sensorimotor deficit syndrome. Brain tumours constitute a further model differing from stroke by their slow lesion dynamics. Evidence from functional neuroimaging and transcranial magnetic stimulation will be presented showing that recovery of hand function is related to reorganization of local perilesional and large-scale circuits involving the contralesional hemisphere.

Recruitment of contralesional motor cortex in stroke patients with recovery of hand function

In neuroimaging studies of stroke patients, coactivation may account for increased recruitment of bilateral motor areas when moving the affected limb. Here we studied eight patients after stroke with fMRI and simultaneous EMG. Bilateral recruitment of premotor and primary motor cortices was evident in five patients with strictly unilateral performance per EMG. Because patients had excellent motor recovery, this increased recruitment suggests an adaptive response to the infarct.

Functional activation within the PI–DWI mismatch region in recovery from ischemic stroke: preliminary observations

In this study, we sought to investigate if brain tissue affected by ischemia can accommodate areas of activation related to restoration of brain function following ischemic stroke. In two patients perfusion imaging (PI) and diffusion weighted imaging (DWI) obtained in the acute phase after stroke was coregistered with BOLD imaging of brain functions acquired when profound recovery had occurred. Both patients suffered from thrombembolic brain infarction due to dissection of the internal carotid artery (ICA) characterized by a severe PI-DWI mismatch in the acute stage of stroke. Following ICA recanalization and clinical recovery BOLD imaging showed task-specific activation adjacent to the infarct lesion within the former PI-DWI mismatch area. The data in these two stroke patients provide evidence that brain tissue at risk of infarction as shown by the PI-DWI mismatch can survive and, thereby, constitute the major site underlying post-ischemic recovery.

Concepts on neurological disease evolution

Degenerative neurological diseases evolve progressively with an insidious onset, while relapsing neurological diseases may remit completely or result in progressive deficits. Since the affected systems can be assessed by clinical evaluation and ascribed to disease-specific pathology--today already in vivo using neuroimaging, the mechanisms underlying neurological disease manifestation can also be studied. For the most frequent neurological diseases with a relapsing clinical course, such as multiple sclerosis, brain infarction and epilepsy, it is shown that disease-specific aetiopathogenesis, lesion-specific pathophysiology and unspecific bystanders determine disease manifestation. Nevertheless, prediction of progression or relapse of a neurological disease is poor due to ill-defined relations of molecular genetic markers and disease evolution. Recent research on aetiopathogenesis and pathophysiology providing new perspectives for selective therapeutic interventions and relapse prevention is discussed.

The effect of combined thrombolysis with rtPA and tirofiban on ischemic brain lesions

To determine the effect of systemic thrombolysis with low-dose recombinant tissue plasminogen activator (rtPA) and the body-weight adjusted platelet GPIIb/IIIa receptor antagonist tirofiban, the authors performed lesion volumetry on magnetic resonance perfusion and diffusion images recorded before thrombolysis and on T2-weighted magnetic resonance images on day 8. Treatment with rtPA and tirofiban (n = 13) resulted in a 50% lesion reduction (p < 0.03), while lesion reduction was less in rtPA treatment (n = 16) and absent in nontreated patients (n = 18).

Use-dependent cortical plasticity in thalidomide-induced upper extremity dysplasia: evidence from somaesthesia and neuroimaging

In this study cerebral reorganization was investigated in thalidomide-damaged subjects who use their feet to compensate for their malformed upper extremities. Tactile localization across toes was combined with fMRI to study use-dependent plasticity of the human somatosensory cortex. The manner of compensatory foot use was assessed by a questionnaire. In the behavioural experiment toes were stimulated with above threshold monofilaments and subjects had to report which toe was stimulated. When feet were employed for all everyday actions subjects made significantly fewer errors in the localization task. In subjects who use their feet only for specific actions such as grasping objects there were as many localization errors as in the control group of thalidomide-affected subjects with normal extremities. However, the patterns of mislocalizations were different with less errors occurring for the toe of the dominant foot involved in these actions. Functional MRI showed stronger haemodynamic responses to electrical stimulation of the toes in subjects using their feet for everyday actions as compared to controls. Our data show that long-term use of the feet for fine sensorimotor skills leads to better performance in tactile localization and changes in cerebral SI representation supporting the notion of use-dependent plasticity in the somatosensory cortex.

The role of V5 (hMT+) in visually guided hand movements: an fMRI study

Electrophysiological studies in animals suggest that visuomotor control of forelimb and eye movements involves reciprocal connections between several areas (striate, extrastriate, parietal, motor and premotor) related to movement performance and visuospatial coding of movement direction. The extrastriate area MT [V5 (hMT+) in humans] located in the "dorsal pathway" of the primate brain is specialized in the processing of visual motion information. The aim of our study was to investigate the functional role of V5 (hMT+) in the control of visually guided hand movements and to identify the corresponding cortex activation implicated in the visuomotor tasks using functional magnetic resonance imaging. Eight human subjects performed visually guided hand movements, either continuously tracking a horizontally moving target or performing ballistic tracking movements of a cursor to an eccentric stationary target while fixating a central fixation cross. The tracking movements were back-projected onto the screen using a cursor which was moved by an MRI-compatible joystick. Both conditions activated area V5 (hMT+), right more than left, particularly during continuous tracking. In addition, a large-scale sensorimotor circuit which included sensorimotor cortex, premotor cortex, striatum, thalamus and cerebellum as well as a number of cortical areas along the intraparietal sulcus in both hemispheres were activated. Because activity was increased in V5 (hMT+) during continuous tracking but not during ballistic tracking as compared to motion perception, it has a pivotal role during the visual control of forelimb movements as well.

Left and right superior parietal lobule in tactile object discrimination

Tactile object discrimination is one of the major manual skills of humans. While the exploring finger movements are not perceived explicitly, attention to the movement-evoked kinaesthetic information gates the tactile perception of object form. Using event-related functional magnetic resonance imaging in seven healthy subjects we found one area in the right superior parietal cortex, which was specifically activated by kinaesthetic attention during tactile object discrimination. Another area with similar location in the left hemisphere was related to the maintenance of tactile information for subsequent object discrimination. We conclude that kinaesthetic information is processed in the anterior portion of the superior parietal cortex (aSPL) with a right hemispheric predominance for discrimination and a left hemispheric predominance for information maintenance.

Unified inflectional processing of regular and irregular verbs: a PET study

Psycholinguistic theories propose different models of inflectional processing of regular and irregular verbs: dual mechanism models assume separate modules with lexical frequency sensitivity for irregular verbs. In contradistinction, connectionist models propose a unified process in a single module. We conducted a PET study using a 2 x 2 design with verb regularity and frequency. We found significantly shorter voice onset times for regular verbs and high frequency verbs irrespective of regularity. The PET data showed activations in inferior frontal gyrus (BA 45), nucleus lentiformis, thalamus, and superior medial cerebellum for both regular and irregular verbs but no dissociation for verb regularity. Our results support common processing components for regular and irregular verb inflection.

Representational cortical plasticity associated with brain tumours: evidence from laser-induced interstitial thermotherapy

OBJECTIVES

To test the hypothesis that cortical plasticity related to destructive tumour growth is functionally relevant. This hypothesis predicts that function is dependent on the intactness of tissue surrounding the tumour.

MATERIAL AND METHODS

Eight patients underwent laser-induced interstitial thermotherapy (LITT) for minimally invasive palliative treatment of brain tumours located in eloquent frontal motor regions including the primary motor cortex. A multimodal approach was used to assess the functional outcome of patients after LITT in detail.

RESULTS

Following LITT, motor function deteriorated in four patients. In three of these four patients the LITT-induced lesion involved minimal parts of adjacent non-tumorous tissue. By contrast, the other four patients whose LITT-induced signal changes were confined to the tumour, showed no functional deficits.

CONCLUSION

These findings support the idea that peri-tumorous neuronal circuitry in motor competent areas may permanently take over those functions that were formerly represented in the neuronal tissue destroyed by the tumour.

Carotid surgery in acute symptomatic patients

OBJECTIVES

evaluation of urgent carotid artery surgery with new diagnostic techniques and changing surgical considerations at a university hospital.

DESIGN, MATERIAL AND METHODS

prospective monitoring and assessment of outcome in 67 patients who underwent urgent carotid surgery because of symptomatic extracranial carotid artery involvement. Patients were examined via the stroke unit: duplex sonography was mandatory for diagnosis of extracranial carotid artery disease, as was proof of an open middle cerebral artery (MCA). Assessment of intracerebral damage followed CT or MR imaging procedures. Perioperative and surgical management was standardized. Neurological impairment was assessed pre-, postoperatively and at follow-up using the Rankin scale. "Urgent" was defined as "immediate" after the final diagnostic step had been performed.

RESULTS

within a period of 26 months 67 symptomatic patients (58% stroke, 42% TIA) underwent urgent carotid surgery. Median time from admission to surgery was 2 days. In all but five cases flow through the ICA could technically be restored (93%). Thirty-day mortality was 3% and disease-related morbidity 13%. The one and two year survival rates were 92 and 90%, respectively. No ipsilateral recurrent stroke occurred during follow-up.

CONCLUSIONS

clinical decision-making based on stratified diagnostic workup by means of extra- and intracranial as well as intracerebral hemodynamics using new imaging techniques may select patients who will benefit more from urgent surgery than from conservative management.

Reorganization of motor representation in a patient with epilepsia partialis continua as shown by [O15]-labeled butanol positron emission tomography and functional magnetic resonance imaging

The authors investigated a 38-year-old patient with focal cortical dysplasia in the right precentral cortex using positron emission tomography and functional magnetic resonance imaging to localize the hand and finger motor representations. The patient presented clinically with epilepsia partialis continua, supposed to originate from the perirolandic area harboring the cortical malformation. Both methods revealed an abnormal bilateral activation of motor cortex during left-hand finger movements. The results suggest that the so-called eloquent but nevertheless pathological dysplastic cortex accommodates motor representations.

Neural activity in human primary motor cortex areas 4a and 4p is modulated differentially by attention to action

The mechanisms underlying attention to action are poorly understood. Although distracted by something else, we often maintain the accuracy of a movement, which suggests that differential neural mechanisms for the control of attended and nonattended action exist. Using functional magnetic resonance imaging (fMRI) in normal volunteers and probabilistic cytoarchitectonic maps, we observed that neural activity in subarea 4p (posterior) within the primary motor cortex was modulated by attention to action, while neural activity in subarea 4a (anterior) was not. The data provide the direct evidence for differential neural mechanisms during attended and unattended action in human primary motor cortex.

Ischemic brain tissue salvaged from infarction by the GP IIb/IIIa platelet antagonist tirofiban

In an open pilot study, the authors tested whether the nonpeptide glycoprotein (GP) IIb/IIIa antagonist tirofiban, a highly effective and selective blocker of platelet aggregation, prevents the transition of ischemic brain tissue into the infarct proper as defined by MRI (perfusion-weighted/T2-weighted) in patients with acute ischemic stroke. The infarct volume (T2 lesion after 1 week) was smaller in treated patients (n = 10) compared with matched control subjects (n = 10; p = 0.029) with similar initial perfusion deficit (TTP-maps). The authors conclude that GP IIb/IIIa antagonists have therapeutic potential in acute stroke therapy.

Bleeding risk of tirofiban, a nonpeptide GPIIb/IIIa platelet receptor antagonist in progressive stroke: an open pilot study

BACKGROUND

Glycoprotein (gp) IIb/IIIa-receptor antagonists are highly effective antiplatelet agents with proven efficacy in the treatment of acute coronary and experimental cerebral ischemia. In this study we examined the rate of hemorrhagic transformation and major bleedings in patients with acute stroke treated with tirofiban, a nonpeptide gpIIb/IIIa antagonist.

METHODS

Eighteen patients with progressively deteriorating acute ischemic stroke were treated with body-weight adjusted intravenous tirofiban for a mean period of 46 h and compared with a matched group of 17 acute ischemic clinically stable stroke patients. Cerebral hemorrhage was assessed by cranial imaging 6-10 days after symptom onset.

RESULTS

No major intracranial hemorrhage was observed in either group. Clinically asymptomatic hemorrhagic infarctions type I/II/III were detected in 4/2/0 controls and in 4/1/1 patients of the tirofiban group, respectively (OR = 0.92; 95% CI 0.4-2.5). Clinical outcome scores were not different in both groups (p = 0.18).

CONCLUSIONS

Tirofiban was not associated with a significantly increased cerebral bleeding rate in acute ischemic stroke. Randomized multicenter studies are needed to further evaluate the safety and efficacy of tirofiban in the treatment of acute stroke.

Conscious and subconscious sensorimotor synchronization--prefrontal cortex and the influence of awareness

One of the most compelling challenges for modern neuroscience is the influence of awareness on behavior. We studied prefrontal correlates of conscious and subconscious motor adjustments to changing auditory rhythms using regional cerebral blood flow measurements. At a subconscious level, movement adjustments were performed employing bilateral ventral mediofrontal cortex. Awareness of change without explicit knowledge of the nature of change led to additional ventral prefrontal and premotor but not dorsolateral prefrontal activations. Only fully conscious motor adaptations to a changing rhythmic pattern showed prominent involvement of anterior cingulate and dorsolateral prefrontal cortex. These results demonstrate that while ventral prefrontal areas may be engaged in motor adaptations performed subconsciously, only fully conscious motor control which includes motor planning will involve dorsolateral prefrontal cortex.

Treatment of acute basilar artery thrombosis with a combination of systemic alteplase and tirofiban, a nonpeptide platelet glycoprotein IIb/IIIa inhibitor: report of four cases

In four patients with acute basilar artery thrombosis, complete arterial recanalization and good neurologic outcome were achieved with a treatment combining alteplase with tirofiban. In no cases were cerebral or extracerebral hemorrhagic complications observed. Combined fibrinolytic agents and glycoprotein IIb/IIIa inhibitors may have high potential in the treatment of acute cerebrovascular thrombosis.

Syntactic processing in left prefrontal cortex is independent of lexical meaning

In language comprehension a syntactic representation is built up even when the input is semantically uninterpretable. We report data on brain activation during syntactic processing, from an experiment on the detection of grammatical errors in meaningless sentences. The experimental paradigm was such that the syntactic processing was distinguished from other cognitive and linguistic functions. The data reveal that in syntactic error detection an area of the left dorsolateral prefrontal cortex, adjacent to Broca's area, is specifically involved in the syntactic processing aspects, whereas other prefrontal areas subserve general error detection processes.