Recovery from apraxic deficits and its neural correlate.

BACKGROUND AND OBJECTIVE: Apraxia is a deficit of motor cognition leading to difficulties in actual tool use, imitation of gestures, and pantomiming object use. To date, little data exist regarding the recovery from apraxic deficits after stroke, and no statistical lesion mapping study investigated the neural correlate of recovery from apraxia. Accordingly, we here examined recovery from apraxic deficits, differential associations of apraxia task (imitation vs. pantomime) and effector (bucco-facial vs. limb apraxia) with recovery, and the underlying neural correlates. METHODS: We assessed apraxia in 39 patients with left hemisphere (LH) stroke both at admission and approximately 11 days later. Furthermore, we collected clinical imaging data to identify brain regions associated with recovery from apraxic deficits using voxel-based lesion-symptom mapping (VLSM). RESULTS: Between the two assessments, a significant recovery from apraxic deficits was observed with a tendency of enhanced recovery of limb compared to bucco-facial apraxia. VLSM analyses revealed that within the lesion pattern initially associated with apraxia, lesions of the left insula were associated with remission of apraxic deficits, whereas lesions to the (inferior) parietal lobe (IPL; supramarginal and angular gyrus) and the superior longitudinal fasciculus (SLF) were associated with persistent apraxic deficits. CONCLUSIONS: Data suggest that lesions affecting the core regions (and white matter) of the fronto-parietal praxis network cause more persistent apraxic deficits than lesions affecting other regions (here: the left insula) that also contribute to motor cognition and apraxic deficits.

[5-Year-Follow-up of the MEmbeR Multicenter Study on Medical-Occupational Rehabilitation]. / 5-Jahres-Follow-Up der multizentrischen Evaluationsstudie zur medizinisch-beruflichen Rehabilitation (MEmbeR).

In Germany, medical-occupational rehabilitation represents an essential link between rehabilitation programs focusing either on medical or occupational rehabilitation. Its main objective is return to work. The current study presents the vocational integration 5 years after medical-occupational rehabilitation and determines possible prognostic factors for long-term occupational integration. To evaluate the effectiveness of medical-occupational rehabilitation, a 5-year-follow-up interview was conducted with participants (n=105) of the multicenter study on medical-occupational rehabilitation (MEmbeR). As a main result, 76% of the participants were still employed 5 years after medical-occupational rehabilitation and the return to work rate was 57%. Prognostic factors for long-term occupational integration could not be identified. However, a low degree of disability, an unrestricted capacity for teamwork as well as an unrestricted ability to judge might be beneficial factors for a successful reintegration. The high amount of participants who returned to work 5 years after medical-occupational rehabilitation, supports the concept of medical-occupational rehabilitation. However, more studies are needed to identify further factors influencing the outcome.

[A New Diagnostic Tool for Apraxia in Patients with Right-Hemisphere Stroke: The Revised Cologne Apraxia Screening (KAS-R)]. / Das revidierte Kölner Apraxie-Screening (KAS-R) als diagnostisches Verfahren für Patienten mit rechtshemisphärischem Schlaganfall.

The Cologne Apraxia Screening (KAS) was developed to diagnose apraxia following left-hemisphere (LH) stroke. The present study aims at developing a diagnostic tool for patients with right-hemisphere (RH) stroke (KAS-R) by modifying the test material of the KAS and reducing the test items based on psychometric analyses.A total of 100 patients with RH stroke and 77 healthy control participants were tested. Psychometric analyses led to the exclusion of 8 KAS items. The final KAS-R, consisting of 12 items, shows good internal consistency (α = 0.795) as well as high sensitivity (79.4 %) and specificity (84.4 %). Applying a cut-off value of ≤ 46 (out of 48) points, 39 RH stroke patients were diagnosed with apraxia. Significant correlations were found between the KAS-R and an imitation test as well as expert ratings, indicating high construct validity. The results suggest that the KAS-R is a reliable and valid diagnostic tool for apraxic deficits after RH stroke.

[The MEmbeR Multicenter Study on medical-occupational rehabilitation]. / Multizentrische Evaluationsstudie zur medizinisch-beruflichen Rehabilitation (MEmbeR).

INTRODUCTION: MEmbeR is a prospective multi-center study on medical-occupational rehabilitation in Germany. METHODS: 196 neurological, psychiatric, orthopaedic, and internal medicine patients from 21 rehabilitation centres all across Germany have been enrolled and followed-up for 2 years after discharge. Primary outcome parameter was defined as return to work. Further, the SF-12 and a Mini-ICF-Rating have been used. RESULTS: Mean age was 34.1 (9.9) years, length of stay 150.0 (223.5) days. Prior to occupational rehabilitation, 69.9% were unable to work, 2 years after discharge only 5.6%. Rate of participants seeking a job was reduced from 19.7% to 3.1%. In summary, 78.1% returned to work. Employed participants were younger (32.8 [9.7] vs. 38.5 [9.4] years, p=0.001) and less disabled (Degree of Disablement [GdB]: 20.0 [31.2] vs. 36.1 [33.7], p<0.05). CONCLUSION: The multicenter cohort study MEmbeR provides further knowledge about the outcome of medical-occupational rehabilitation in Germany.

Combined space and alertness related therapy of visual hemineglect: effect of therapy frequency.

The combined efficacy of space- and alertness related training in chronic hemineglect was tested behaviorally and in a longitudinal fMRI study. Earlier results had shown that both space as well as alertness related training as single intervention methods lead to short term improvement which, however, is not stable for longer time periods. The neurobiological data obtained in these studies revealed differential cortical reorganization patterns for the two training approaches thereby leading to the hypothesis that a combination of both trainings might result in stronger and longer lasting effects. The results of our current study, however, - at least at first glance - do not clearly corroborate this hypothesis, because neither alertness training alone nor the combination with OKS on the group level led to significant behavioral improvement, although four of the six patients after alertness and even more after combined training showed a higher percentage of behavioral improvement than during baseline. Despite the lack of clearcut behavioral training induced improvement we found right parietal or fronto-parietal increase of activation in the imaging data immediately after combined training and at follow-up 3 weeks later. The study design had called for splitting up training time between the two training approaches in order to match total training time with our earlier single training studies. The results of our current study are discussed as a possible consequence of reduced training time and intensity of both training measures under the combined training situation.

Stress-stimulated volitional coping competencies and depression in multiple sclerosis.

OBJECTIVE: The present study examined the relationship between volitional modes of coping (self-regulation, volitional inhibition, and self-control) and depression in individuals with multiple sclerosis. METHODS: A cross-sectional study of 121 participants aged 22-60 years with clinically defined MS who were consecutively admitted to a neurological rehabilitation center during a 23-month period. Correlation analyses and hierarchical regressions were conducted to evaluate the predictive value of volitional competencies (Volitional Components Questionnaire, short form, VCQ-S) on depression (Centre for Epidemiologic Studies Depression Scale, CES-D), while controlling for demographic (age, gender, and education) and certain clinical variables (Expanded Disability Status Scale, EDSS; disease duration; and Modified Fatigue Impact Scale, MFIS). RESULTS: Hierarchical regression analyses of depression revealed a model in which 68% of the variance in the CES-D was explained by daily stress situations (VCQ-S), self-regulation (VCQ-S), fatigue (MFIS), and education. However, when the analysis included only participants who had scored above the cut-off of the CES-D (n=42), the VCQ-S factor volitional inhibition seemed to play a more relevant part in depression. In particular, the VCQ-S scales stimulation of self-access, stimulation of volitional inhibition, self-motivation, and emotional perseverance/state orientation after failure appear to be valuable predictors on CES-D. CONCLUSIONS: The results suggest that personality-accentuated volitional coping competencies elicited by daily stressful situations could be a relevant factor for depressive mood states in individuals with MS. However, to clarify the exact relationships of this rather circular framework, longitudinal study designs with objective measurements and a stronger focus on MS-specific stressors are needed.

Visual extinction in relation to visuospatial neglect after right-hemispheric stroke: quantitative assessment and statistical lesion-symptom mapping.

BACKGROUND: Visual neglect and extinction are two common neurological syndromes in patients with right-hemispheric brain damage. Whether and how these two syndromes are associated or share common neural substrates is still a matter of debate. METHODS: To address these issues, the authors investigated 56 patients with right-hemispheric stroke with a novel diagnostic test to detect extinction and neglect. In this computerised task, subjects had to respond to target stimuli in uni- and bilateral stimulation conditions with detection probabilities being assessed. A cluster-analytical approach identified 18 patients with neglect and 13 patients with extinction. Statistical lesion-symptom mapping analyses with measures for extinction and neglect were performed. RESULTS: Extinction and neglect co-occurred in a subset of patients but were also observed independently from each other, thereby constituting a double dissociation. Lesions within the right inferior parietal cortex were significantly associated with the severity of visual extinction. Visuospatial neglect was related to damage of fronto-parietal brain regions, with parieto-occipital areas affecting line bisection and dorsal fronto-parietal areas affecting cancellation task performance, respectively. CONCLUSION: Quantifying lesion-induced symptoms with this novel paradigm shows that extinction and neglect are dissociable syndromes in patients with right-hemispheric stroke. Furthermore, extinction and neglect can be related to differential neural substrates, with extinction being related to focal brain damage within the right inferior parietal cortex.

[Rehabilitation of Parkinson's patients with deep brain stimulation. Experiences of the Neurological Rehabilitation Center Godeshöhe]. / Rehabilitation von Parkinson-Patienten mit Tiefenhirnstimulation. Erfahrungen des Neurologischen Rehabilitationszentrums Godeshöhe.

BACKGROUND: Deep brain stimulation (DBS) of the subthalamic nucleus (STN) has become an important therapeutic option in patients with advanced Parkinson's disease (PD). An increasing number of patients are referred for hospital rehabilitation after initial programming. The role of further DBS and medication adjustments for this rehabilitation therapy is uncertain. METHODS: This study was a retrospective analysis of a hospital rehabilitation program with a systematic algorithm to improve DBS efficacy in PD patients referred within 3 months after electrode implantation. This study analyzed (1) changes of stimulation parameters and medication and (2) changes in the performance of activities of daily living as measured by the Barthel index. RESULTS: After an average of 20.4±10.7 days following surgery 95 PD patients were hospitalized for an average rehabilitation period of 29.0±11.2 days. Technical dysfunctions were found in 3 (3.1%) patients and a bilateral electrode dislocation in 1 (1.1%) patient. Stimulation parameters were adjusted on 7.3±4.0 days, sometimes with several adjustments on the same day. Until discharge the stimulation amplitude was significantly increased from 2.1±0.8 V to 3.0±0.8 V. Moreover, in 70 (73.7%) patients active stimulation contacts were changed. The mean levodopa equivalent dosage decreased from 529±290 mg/die to 300±277 mg/die. The Barthel index increased significantly by 10.3±12.4 points. CONCLUSION: Further DBS and medication adjustments play an important role for hospital rehabilitation of PD patients after initial DBS programming in DBS centers.

Bidirectional alterations of interhemispheric parietal balance by non-invasive cortical stimulation.

Transcranial direct current stimulation is a painless, non-invasive brain stimulation technique that allows one to induce polarity-specific excitability changes in the human brain. Here, we investigated, for the first time in a 'proof of principle' study, the behavioural effect of transcranial direct current stimulation on visuospatial attention in both healthy controls and stroke patients suffering from left visuospatial neglect. We applied anodal, cathoP:dal or sham transcranial direct current stimulation (57 microA/cm(2), 10 min) to the left or right posterior parietal cortex. Using a visual detection task in a group of right-handed healthy individuals (n = 20), we observed that transcranial direct current stimulation enhanced or impaired performance depending on stimulation parameters (i.e. current polarity) and stimulated hemisphere. These results are in good accordance with classic models of reciprocal interhemispheric competition ('rivalry'). In a second experiment, we investigated the potential of transcranial direct current stimulation to ameliorate left visuospatial neglect (n = 10). Interestingly, both the inhibitory effect of cathodal transcranial direct current stimulation applied over the unlesioned posterior parietal cortex and the facilitatory effect of anodal transcranial direct current stimulation applied over the lesioned posterior parietal cortex reduced symptoms of visuospatial neglect. Taken together, our findings suggest that transcranial direct current stimulation applied over the posterior parietal cortex can be used to modulate visuospatial processing and that this effect is exerted by influencing interhemispheric reciprocal networks. These novel findings also suggest that a transcranial direct current stimulation-induced modulation of interhemispheric parietal balance may be used clinically to ameliorate visuospatial attention deficits in neglect patients.

[Shaping the future of vocational rehabilitation of adults: eight fields of action as starting points for a cross-actor innovation process]. / Die Zukunft der beruflichen Rehabilitation Erwachsener gestalten: Acht Handlungsfelder als Ausgangspunkt für einen akteursübergreifenden Innovationsprozess.

Established by the Federal Ministry of Labour and Social Affairs (BMAS) in October 2007, the Scientific Expert Group RehaFutur had been commissioned to elaborate cornerstones for the medium- and long-term development of vocational rehabilitation of adults with disabilities (re-integration). Initial questions inter alia were as follows: Which function should vocational rehabilitation have in a service- and knowledge-oriented working world that will increasingly be affected by demographic change? How can disabled persons' right to occupational participation by way of vocational rehabilitation, a right stipulated both under the German constitution and in German law, be realized as needed also in the future? Various fields of action have been derived on the basis, for one, of an investigation of the factors, social law, social and education policy as well as European, influencing vocational rehabilitation and, for the other, of an evaluation of current labour market and demographic developments. Dealt with in the fields of action outlined are the aspects: equitable opportunities of access, developmental and needs orientation, closeness to the real occupational and working world, as well as the role of self-determination and self-responsibility. The fields of action are to be understood as framework concept for shaping a cross-actor innovation process. Sustainable vocational rehabilitation is characterized in particular by the fact that it is specifically targeted at promoting disabled persons' self-determination and self-responsibility actively using these in the process and that it strengthens an independent lifestyle, ensures social participation by inclusive structures; also, it facilitates continued participation in working life by ongoing education involving holistic development of professional and personal competencies oriented towards the individual's resources and potentials, safeguarding it by systematic networking with companies. The concept presented for vocational rehabilitation of adults with disabilities encompasses a change of paradigms which service carriers and providers will have to face jointly and including the service users, the rehabilitants.

Alertness-training in neglect: behavioral and imaging results.

PURPOSE: It has been proposed that the right hemisphere alerting network co-activates, either directly or via the brainstem, the spatial attention system in the parietal cortex. The observation that measures of impaired alertness and sustained attention can be used to predict the outcome of neglect might suggest such a relationship, too. The aim of the present study was to investigate the effects of alertness training on hemispatial neglect. METHOD: A three-week computerised alertness training was applied to patients with chronic (> 3 months) stable visuospatial hemineglect. Training effects were investigated both in a single case and in a group of 7 patients by means of neuropsychological tests and functional magnetic resonance imaging (fMRI). RESULTS: After the training, the patients showed a significant improvement in a neglect test battery above any natural fluctuation during a three-week baseline phase. Improvements in the neglect tasks were accompanied by an increase of both right and left hemisphere frontal, anterior cingulate and superior parietal activation, areas known to be associated with both alertness and spatial attention. Four weeks after the end of the training, the patients' neglect test performance had mostly returned to baseline. Despite decreases of activation in some of the initially reactivated areas, increases in neural activity bilaterally in frontal areas, in the right anterior cingulate cortex, the right angular gyrus and in the left temporoparietal cortex remained. An Optokinetic Stimulation Training (OKS) in a control group of another 7 neglect patients led to comparable behavioral results. After the training, however, there was a reactivation mainly in posterior parts of both hemispheres suggesting training specific functional reorganization. CONCLUSION: The limited stability of the behavioral and reactivation results over time demonstrates that a three-week alertness or OKS training alone does not result in long lasting behavioral improvements and stable reactivation patterns in every patient. We rather suggest that combining alertness and spatial attention oriented training procedures might lead to a more stable amelioration of neglect symptoms.

Impact of alertness training on spatial neglect: a behavioural and fMRI study.

The effects of a 3-week computerised alertness training on chronic (>3 months) visuospatial hemineglect were investigated prospectively in seven patients by means of neuropsychological tests and functional magnetic resonance imaging (fMRI). Following the alertness training, the group showed improved alertness and a significant improvement in the performance of a neglect test battery over and above any improvement during a 3-week baseline phase. Improvements in the neglect tasks were accompanied by an increase of right hemisphere neural activity in frontal cortex, anterior cingulate cortex, precuneus, cuneus and angular gyrus. These areas have previously been associated with alertness and spatial attention. A similar pattern of increased neural activity was found for the left hemisphere. Four weeks after the end of the training, the patients' neglect test performance had mostly returned to baseline, while the increases in neural activity bilaterally in frontal areas, in the right anterior cingulate cortex, the right angular gyrus and the left temporoparietal cortex remained. The data show that a 3-week computerised alertness training can improve performance both in alertness and neglect tests and that these behavioural improvements are associated with reactivation in areas associated with alerting and visuospatial attention. The limited stability of these effects over time suggests that a 3-week alertness training alone does not result in long lasting improvements in every patient, but refining the treatment protocol may lead to a more stable amelioration of neglect symptoms.

[Interactive driving simulation--a new approach to diagnosis and rehabilitation of driving skills]. / Interaktive Fahrsimulation--ein neuer Weg zur Diagnose und Rehabilitation der Fahrtauglichkeit.

Until recently, major methodological problems were faced in the assessment and rehabilitation of driving ability in neurological patients, concerning practical driving lessons and driving tests as well as neuropsychological tests and therapies. The use of highly-advanced driving simulators may solve parts of this problem. However, a basic requirement for effective rehabilitation is the patients' acceptance of this method. In a semi-standardized interview with 56 patients we found that the driving simulator recently installed in the Neurological Rehabilitation Centre "Godeshöhe" was rated mainly positively. Also, patients experienced the simulator to be motivating, effective and informative. Hence, a very important prerequisite for successful use of driving simulators in neurological rehabilitation is given.

Piracetam improves activated blood flow and facilitates rehabilitation of poststroke aphasic patients.

BACKGROUND AND PURPOSE: In a prospective, double-blind, placebo-controlled study, it was investigated whether piracetam improves language recovery in poststroke aphasia assessed by neuropsychological tests and activation PET measurement of cerebral blood flow. METHODS: Twenty-four stroke patients with aphasia were randomly allocated to 2 groups: 12 patients received 2400 mg piracetam twice daily, 12 placebo. Before and at the end of the 6-week treatment period in which both groups received intensive speech therapy, the patients were examined neuropsychologically and studied with H(2)(15)O PET at rest and during activation with a word-repetition task. Blood flow was analyzed in 14 language-activated brain regions defined on reconstructed surface views from MRI coregistered to the PET images. RESULTS: Before treatment, both groups were comparable with respect to performance in language tasks and to type and severity of aphasia. In the piracetam group, increase of activation effect was significantly higher (P:<0.05) in the left transverse temporal gyrus, left triangular part of inferior frontal gyrus, and left posterior superior temporal gyrus after the treatment period compared with the initial measures. The placebo group showed an increase of activation effect only in the left vocalization area. In the test battery, the piracetam group improved in 6 language functions, the placebo group only in 3 subtests. CONCLUSIONS: Piracetam as an adjuvant to speech therapy improves recovery of various language functions, and this effect is accompanied by a significant increase of task-related flow activation in eloquent areas of the left hemisphere.

Differential capacity of left and right hemispheric areas for compensation of poststroke aphasia.

As previous functional neuroimaging studies could not settle the controversy regarding the contribution of dominant and subdominant hemisphere to recovery from poststroke aphasia, language performance was related to H2(15)O-positron emission tomographic activation patterns in 23 right-handed aphasic patients 2 and 8 weeks after stroke. In patients classified according to the site of lesion (frontal, n = 7; subcortical, n = 9; temporal, n = 7) and in 11 control subjects, flow changes caused by a word repetition task were calculated in 14 regions representing eloquent and contralateral homotopic areas. These areas were defined on coregistered magnetic resonance imaging scans and tested for significance (Bonferroni corrected t test, alpha = 0.0036). At baseline, differences in test performance were only found between the subcortical and temporal group. The extent of recovery, however, differed and was reflected in the activation. The subcortical and frontal groups improved substantially; they activated the right inferior frontal gyrus and the right superior temporal gyrus (STG) at baseline and regained left STG activation at follow-up. The temporal group improved only in word comprehension; it activated the left Broca area and supplementary motor areas at baseline and the precentral gyrus bilaterally as well as the right STG at follow-up, but could not reactivate the left STG. These differential activation patterns suggest a hierarchy within the language-related network regarding effectiveness for improvement of aphasia; ie, right hemispheric areas contribute, if left hemispheric regions are destroyed. Efficient restoration of language is usually only achieved if left temporal areas are preserved and can be reintegrated into the functional network.

Collateral inhibition of transcallosal activity facilitates functional brain asymmetry.

The corpus callosum is the largest connection between the functionally asymmetric cerebral hemispheres. The objective of this study was to measure functional activity of callosal fiber tracts during speech processing. We analyzed the regional glucose metabolism of the corpus callosum and of speech-relevant cortical areas in 10 normal individuals at rest and during word repetition. We used three-dimensionally registered magnetic resonance imaging to visualize the individual brain morphology and high-resolution positron emission tomography for metabolic measurements. The task-induced metabolic changes of the callosal midbody and isthmus had a significant negative correlation with key regions of language processing in the left inferior frontal cortex (Brodmann's area 44) and in the right superior temporal cortex (Brodmann's area 22) (e.g., correlation of metabolic changes in the surface aspects of the right Brodmann's area 22 and the callosal midbody/isthmus: r = -0.91, P < 0.001). The study indicates that language processing in asymmetrically organized cortical areas inhibits the reciprocal transcallosal information exchange in favor of the lateralized mental operation. Our data agree with anatomic, electrophysiologic, and pharmacologic experiments that point to the important role of collateral inhibition for the transcallosal information exchange.

Brain plasticity in poststroke aphasia: what is the contribution of the right hemisphere?

The brain may use two strategies to recover from poststroke aphasia: the structural repair of primarily speech-relevant regions or the activation of compensatory areas. We studied the cortical metabolic recovery in aphasic stroke patients with positron emission tomography (PET) at rest and during word repetition. The left supplementary motor area (SMA) showed the most prominent compensatory activation in the subacute state of stroke. The restitution of the left superior temporal cortex determined the long-term prognosis of aphasia. The brain recruited right-hemispheric regions for speech processing, when the left-hemispheric centers were permanently impaired. This strategy, however, was significantly less effective than the repair of the original speech-relevant network.

Cerebral networks and functional brain asymmetry: evidence from regional metabolic changes during word repetition.

Word repetition causes a significant bilateral metabolic increase in both superior temporal cortices. Frontal speech areas are less activated despite their presumable speech competence. We investigated in this study the relationship between frontal and temporal cortical areas during word repetition. We measured regional cerebral metabolic rates of glucose (CMRGI) in 15 normal subjects with positron emission tomography (PET) at rest and during word repetition. Significant correlations connected frontal and temporal areas of both hemispheres, notwithstanding their different levels of mean metabolic activation. The left planum temporale was a hub of significant interregional correlations, in contrast to its contralateral mate. This study indicates that an asymmetric network of significant connections orchestrates the speech-relevant cortical areas according to the actual needs of speech processing.

Speech-induced cerebral metabolic activation reflects recovery from aphasia.

Six stroke patients with clinically significant aphasia were studied 4 weeks and again 12-18 months after their first left hemispheric ictus. The regional cerebral metabolic rate of glucose (rCMRglc) was measured repeatedly by PET at rest and during word repetition, and severity of speech impairment was assessed by a neuropsychologic test battery. The patterns of speech-associated activation of glucose metabolism were related to improvement in language performance as measured by the Token test. Three patients experienced significant recovery from aphasia (Token test: 47 to 3, 45 to 12, and 37 to 5 points, respectively), whereas 3 patients had poor outcome (Token test from 48 to 45, and from 47 to 39 and 24, respectively). Good recovery was related to activation of left hemispheric speech areas surrounding the infarct, especially left superior temporal gyrus. In contrast, the 3 patients with persistent aphasia showed rCMRglc recruitment in right hemispheric regions and were unable to activate left hemispheric speech areas on follow-up. These results indicate that favorable outcome is related to partial sparing of speech areas of the dominant hemisphere that can be (re-) activated. Predominant recruitment of contralateral areas is not efficacious for a considerable recovery from aphasia. It rather indicates unspecific involvement of widespread networks in the effort to perform a complex task.