[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.

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.

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.

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.

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.

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.

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.

Profiles of language impairment in primary progressive aphasia.

OBJECTIVE: The profile of language impairment in patients with primary progressive aphasia in comparison with the language impairment in patients with Alzheimer's disease and after stroke. DESIGN: The Western Aphasia Battery and the Mattis Dementia Rating Scale evaluated the language and cognitive impairment. Follow-up studies were done 1 to 5 years after the initial testing in seven of 10 patients with primary progressive aphasia, and a postmortem examination of the brain was done in two patients. SETTING: All 10 patients with primary progressive aphasia were previously healthy, community-dwelling persons when first tested. PATIENTS AND OTHER PARTICIPANTS: All patients with primary progressive aphasia reported at least a 2-year history of slowly progressive aphasia without other signs of global dementia. The initial Western Aphasia Battery results of the 10 patients with primary progressive aphasia were compared with those of a sample of 10 patients with probable Alzheimer's disease and with those of a sample of 10 patients with aphasia due to a left hemispheric stroke. Both reference samples were matched for age and sex; the sample with stroke-caused aphasia was additionally matched for the aphasia type. RESULTS: Expressive language disability with reduced speech fluency and anomia but preserved language comprehension and nonverbal cognition were typical features in early stages of primary progressive aphasia. Spontaneous speech was significantly more impaired in patients with primary progressive aphasia in comparison with those with aphasia after left hemisphere stroke and with language impairment in patients with Alzheimer's disease. Follow-up examinations revealed continuous, often rapid deterioration of language impairment. The neuropathological examination showed Alzheimer's disease in one patient and Pick's disease in the other. CONCLUSION: The profile of aphasia suggests that primary progressive aphasia tends to affect anterior parts of the language-dominant cortex first.

Cerebral glucose metabolism as a predictor of recovery from aphasia in ischemic stroke.

OBJECTIVE: The recovery of language function seen in poststroke aphasia is significantly related to the severity of the initial neurologic deficit. However, a great deal of variability still remains in the improvement that is actually achieved. To detect predictors that will help in explaining this variability, positron emission tomography (PET) and fluorodeoxyglucose F 18 (18-F-fluorodeoxyglucose) were used and the results were analyzed by stepwise regression. DESIGN: Using PET imaging after injection of fluorodeoxyglucose F 18, the regional changes in glucose metabolism in 26 patients at a period of 12 to 18 days following an ischemic stroke involving the left middle cerebral artery were examined. A second PET examination was performed on 17 of our 26 patients who were able to perform speech activation exercises. All patients received an initial and a 4-month follow-up evaluation of language performance. SETTING: During the two PET studies and the first language assessment, the patients were hospitalized in a neurologic clinic. The follow-up evaluation of language performance was performed when the patients were ambulatory. PATIENTS: Twenty-six patients (10 women, 16 men; aged 38 to 77 years; mean +/- SD, 60 +/- 9.2 years) were selected in the study. Their aphasias were of various types and of varying severity ranging from mild impairment to severe global aphasia. MAIN OUTCOME MEASURES: For the stepwise regression analysis of variables, the following variables were analyzed in resting and activation PET to explain residual variance from the first to the second Token Test: regional cerebral metabolic rate for glucose of infarct and mirror region, left and right cerebral and cerebellar hemispheres, left and right Broca's area, left and right Wernicke's area, and left and right temporoparietal cortex. RESULTS: As was expected, early and late Token Tests exhibit a high correlation (.85). The stepwise regression analysis shows that only the left cerebral hemisphere glucose value of the resting PET had significant effect on the residual variance of the Token Test regression. Regional metabolic rates during speech activation had the largest contribution to a significant recovery from aphasia. The infarct area and its corresponding mirror region, the left Broca's area, and the entire left cerebral hemisphere accounted for 80% of the residual variance. CONCLUSIONS: These results emphasize not only the application of PET activation studies in the prediction of a tissue's potential reserve capacity but also the importance of left hemisphere integrity in the recovery of functional language.

Widespread functional effects of discrete thalamic infarction.

In order to investigate functional effects of various thalamic structures on metabolism in remote, morphologically intact cerebral regions, we used positron emission tomography of (18F)-2-fluoro-2-deoxy-D-glucose to study regional cerebral metabolic rates of glucose (rCMRGlu) in 11 patients with chronic unilateral or bilateral infarcts strictly confined to the thalamus. Patients were grouped according to computed tomographic scans showing anterior (three), medial (four), or posterior (four) lesions. Compared with a matched group of 11 healthy subjects (hemispheric CMRGlu 35.2 +/- 3.49 mumol/100 g per minute), glucose metabolism was significantly lower in the hemisphere ipsilateral to the infarction (31.2 +/- 2.97 mumol/100 g per minute). Patients with bilateral infarcts had lower hemispheric CMRGlu (29.9 +/- 2.74 mumol/100 g per minute) than those with unilateral lesions (32.2 +/- 2.97 mumol/100 g per minute). Depending on infarct location within the thalamus, there was differential depression of rCMRGlu, with the largest effects on frontal and occipital areas in medial infarctions. Except for ipsilateral thalamic deactivation, metabolic patterns with anterior thalamic infarcts were close to normal, while posterior infarcts mostly depressed rCMRGlu in the visual and in the inferior limbic cortex. Cerebellar metabolic rates were within normal limits in most cases. These patterns of regional cerebral deactivation may be related to categories of thalamic projections--intrathalamic, to limbic system and basal ganglia, diffuse to most cortical areas, and specific to defined neocortical areas. Even small brain lesions may have widespread functional sequelae, potentially demonstrable by positron emission tomography.

Planum temporale and Brodmann's area 22. Magnetic resonance imaging and high-resolution positron emission tomography demonstrate functional left-right asymmetry.

OBJECTIVE: To describe the registered analysis of magnetic resonance imaging and glucose metabolic data acquired with positron emission tomography to determine the relationship between structure and function of temporal lobe cortical structures between the left and right hemispheres. BACKGROUND: The dominance of the left cerebral hemisphere is associated with a preponderance of the left planum temporale. SUBJECTS AND METHODS: Fifteen subjects without signs or symptoms of a neurological disorder. Three-dimensional-registered magnetic resonance imaging and positron emission tomography with the use of fludeoxyglucose F18 and a high-resolution positron emission tomography scanner. Analysis of regional metabolic activation during single-word repetition on matched parasagittal magnetic resonance imaging and positron emission tomography. RESULTS: The planum temporale was bilaterally activated without left-right asymmetry. The metabolic increase was asymmetric within the left Brodmann's area (BA) 22. The part of the left BA 22 that was buried in the superior temporal sulcus was significantly less activated than the part of BA 22 on the surface of the superior temporal gyrus. The metabolic activation in the sulcal part of the left BA 22 had a significant inverse correlation with the anatomical predominance of the left planum temporale (r = .71, P = .003) and a significant direct correlation with the metabolic activation in the surface aspects of the right BA 22 (r = .82, P < .001). CONCLUSION: Brodmann's area 22 is a critical feature of language dominance and is also important with regard to the exchange of information between the two hemispheres.

Long-term prognosis of poststroke aphasia studied with positron emission tomography.

OBJECTIVE: To evaluate positron emission tomography with the use of fludeoxyglucose F 18 as a predictor of the long-term outcome of poststroke aphasia. BACKGROUND: Positron emission tomography shows functional deficits after stroke even in morphologically intact brain regions. The regional metabolic impairment can be related to the clinical deficit. Little is known about whether regional hypometabolism early after stroke predicts the long-term prognosis of stroke sequelae. PATIENTS AND METHODS: Twenty-two patients with language disturbance caused by a single lesion in the territory of the left middle cerebral artery were studied with fludeoxyglucose positron emission tomography and with a neuropsychological test battery that included a test of receptive language (Token Test) and a test of word fluency (/f/, /a/, /s/ test). The neuropsychological test was readministered about 2 years after the initial test. RESULTS: Regional cerebral metabolic rates of glucose measured early after stroke showed a highly significant correlation with the results of the 2-year follow-up test. The receptive language disorder best correlated with cerebral metabolic rates of glucose in the left superior temporal cortex, and word fluency correlated with cerebral metabolic rates of glucose in the left prefrontal cortex. CONCLUSION: Cerebral metabolic rates of glucose in speech-relevant brain regions measured early after stroke are a predictor of the eventual outcome of aphasia.

Positron emission tomography demonstrates frontal cortex and basal ganglia hypometabolism in dystonia.

We studied 15 dystonic patients with positron emission tomography (PET) and (18F)-2-fluoro-2-deoxy-D-glucose (FDG). The group comprised patients with focal (n = 5), multifocal (n = 1), and generalized (n = 4) dystonia as well as patients with hemidystonia (n = 5). The age at onset was during childhood in four, during adolescence in two, and during adulthood in nine of the subjects. In dystonic patients, global cerebral glucose metabolism was unaltered when compared with normal controls, whereas the pattern of regional cerebral metabolic rate for glucose (rCMR[Glu]) was significantly different (p = 0.0001). rCMR(Glu) was significantly decreased in the caudate and lentiform nucleus and in the frontal projection field of the mediodorsal thalamic nucleus. The study confirms the concept that dystonia is caused by impaired connections between the basal ganglia, the thalamus, and frontal association areas.

Regional metabolic correlates of Token test results in cortical and subcortical left hemispheric infarction.

We investigated 26 right-handed patients who had aphasia caused by a single infarct in the territory of the left middle cerebral artery (MCA) with cranial CT, positron emission tomography, and a standard language test battery including the Token test. The patients represented an unselected sample of various infarct locations within the left MCA territory and showed a wide range of aphasia types and severity. Stepwise regression analysis revealed that Token test performance mainly depended on parietotemporal metabolism, irrespective of infarct location. Frontal and basal ganglia metabolism did not contribute significantly to Token test performance. These results suggest that disturbance of language comprehension is due to parietotemporal cortical dysfunction in all types of left MCA infarction. Infarcts restricted to basal ganglia or the anterior part of the MCA territory apparently do not disturb language comprehension directly, but via their remote effects on parietotemporal metabolism.