RESUMO
BACKGROUND: Sensory deficits are common after stroke, leading to disability and poor quality of life. Although lesion locations and patterns of structural brain network disruption have been associated with sensory disturbances, the relation with functional lesion connectivity has not yet been established. METHODS: Retrospective analysis of a prospective cohort study of patients with acute ischemic stroke. Indirect functional lesion network mapping to identify brain regions remote from the primary lesion associated with deficits on the Rivermead Assessment of Somatosensory Performance test. Associations between Rivermead Assessment of Somatosensory Performance scores and functional connectivity of the lesion site with prespecified components of the somatosensory system. RESULTS: One hundred one patients (mean age, 62 years; 32% women) from the TOPOS study (Topological and Clinical Prospective Study About Somatosensation in Stroke). Lesion network mapping identified a bilateral fronto-parietal network associated with sensory deficits in the acute phase after stroke. There were graded associations between deficits and functional lesion connectivity to sensory cortices, but not the thalamus. CONCLUSIONS: Infarcts in brain regions remote from, but functionally connected, to the somatosensory network are associated with somatosensory deficits measured by the Rivermead Assessment of Somatosensory Performance test, reflecting the hierarchical functional anatomy of sensory processing. Further research is needed to translate these findings into improved prognosis and personalized rehabilitation strategies.
Assuntos
AVC Isquêmico , Acidente Vascular Cerebral , Humanos , Feminino , Pessoa de Meia-Idade , Masculino , AVC Isquêmico/complicações , Estudos Prospectivos , Estudos Retrospectivos , Qualidade de Vida , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/diagnóstico por imagem , Mapeamento Encefálico , Imageamento por Ressonância MagnéticaRESUMO
BACKGROUND: We report the case of a patient with recurrent episodes of disturbed memory suggestive of transient epileptic amnesia, and a focal hippocampal lesion typically associated with transient global amnesia. We argue how careful consideration of clinical, electrophysiological and imaging findings can resolve this apparent contradiction and lead to a diagnosis of early symptomatic post-stroke seizures that links brain structure to function in a new, clinically relevant way. CASE PRESENTATION: A 70-year-old patient was identified in clinical practice in our tertiary care centre and was evaluated clinically as well as by repeated electroencephalography and magnetic resonance imaging. The presenting complaint were recurrent episodes of short-term memory disturbance which manifested as isolated anterograde amnesia on neurocognitive evaluation. EEG and MRI revealed predominantly right frontotemporal spikes and a punctate diffusion-restricted lesion in the left hippocampus, respectively. Both symptoms and EEG changes subsided under anticonvulsant treatment with levetiracetam. CONCLUSIONS: Our report contributes to the current discussion of clinical challenges in the differential diagnosis of transient memory disturbance. It suggests that focal diffusion-restricted hippocampal lesions, as seen in TGA, might be ischemic and thus highlights the importance of considering post-stroke seizures as a possible cause of transient memory disturbance.
Assuntos
Amnésia Global Transitória , Idoso , Amnésia , Hipocampo , Humanos , Infarto , ConvulsõesRESUMO
Background and Purpose- About 50% to 80% of stroke survivors present with somatosensory deficits. Somatosensory deficits because of an ischemic stroke are determined by the infarct location. However, a detailed understanding of the long-term effect of lesions on somatosensory performance is lacking. Methods- This prospective observational study enrolled 101 ischemic stroke patients. For voxel-based lesion-symptom mapping, magnetic resonance imaging fluid-attenuated inversion recovery imaging infarct lesions were segmented within 5 days after stroke. Standardized tests such as the National Institutes of Health Stroke Scale and the Rivermead Assessment of Somatosensory Performance were performed during acute stage, after 3 and 12 months. This included bilateral testing for multiple tactile and proprioceptive somatosensory modalities (pressure, light touch, sharp-dull discrimination, temperature discrimination, sensory extinction, 2-point discrimination, and joint position and movement sense). We further study the association of acute somatosensory deficit with functional outcome 12 months after stroke assessed by the modified Rankin Scale using univariate and multiple linear regression analysis also including acute motor deficit assessed by the arm research action test. Results- Sixty patients (59.4%) showed impairment in at least one somatosensory modality. Light touch was most frequently affected (38.7%), whereas temperature was least frequently affected (21.8%). After 3 months, significant recovery was observed in all somatosensory modalities, with only minor additional improvements after 12 months. Voxel-based lesion-symptom mapping revealed significant associations of lesions in the primary and secondary somatosensory and insular cortex with somatosensory deficits. Acute somatosensory deficit was associated with functional outcome at 12 months. However, including the acute motor deficit, somatosensory deficit was no longer an independent predictor of functional outcome. Conclusions- Our study confirms that somatosensory deficits are frequent in acute ischemic stroke but largely recover over time. Infarct lesions in the primary and secondary somatosensory cortex and insula show a robust association with somatosensory impairment. Long-term disability is influenced by somatosensory deficits but driven by motor symptoms.
Assuntos
Isquemia Encefálica/diagnóstico por imagem , Infarto Cerebral/diagnóstico por imagem , Propriocepção , Córtex Somatossensorial/diagnóstico por imagem , Acidente Vascular Cerebral/diagnóstico por imagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Isquemia Encefálica/epidemiologia , Infarto Cerebral/epidemiologia , Feminino , Seguimentos , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Propriocepção/fisiologia , Estudos Prospectivos , Córtex Somatossensorial/fisiologia , Acidente Vascular Cerebral/epidemiologiaRESUMO
BACKGROUND: We investigated changes of cortical thickness and its association with cognitive performance in patients with high-grade carotid artery stenosis without ischemic brain lesions. METHODS: We studied 25 patients with unilateral carotid artery stenosis ≥50% and 25 age-matched controls. All subjects underwent T1-weighted MRI, and cortical thickness was measured in 33 regions of interest in each hemisphere, as well as in brain regions belonging to the vascular territory of the middle cerebral artery (MCA). General linear mixed models were fitted to the dependent variable cortical thickness. Cognitive assessment comprised the Stroop Test and Trail Making Test B. RESULTS: In the linear mixed model, presence of carotid stenosis had no effect on cortical thickness. There was a significant interaction of stenosis and region with a trend towards lower cortical thickness in the MCA region on the side of carotid stenosis. Patients with carotid stenosis performed significantly worse on the Stroop test than controls, but there was no correlation with cortical thickness. CONCLUSION: In patients with carotid stenosis without ischemic brain lesions, neither a clear pattern of reduced cortical thickness nor an association of cortical thickness with cognitive function was observed. Our data do not support the hypothesized association of cortical thinning and cognitive impairment in carotid stenosis.
Assuntos
Estenose das Carótidas/diagnóstico por imagem , Córtex Cerebral/diagnóstico por imagem , Cognição , Disfunção Cognitiva/diagnóstico , Imageamento por Ressonância Magnética , Teste de Stroop , Teste de Sequência Alfanumérica , Idoso , Estenose das Carótidas/complicações , Estenose das Carótidas/fisiopatologia , Estudos de Casos e Controles , Córtex Cerebral/fisiopatologia , Disfunção Cognitiva/etiologia , Disfunção Cognitiva/psicologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos TestesRESUMO
In the past years, there have been increasing research activities focusing on somatosensory symptoms following stroke. However, as compared to the large number of clinical and neuroimaging studies on motor symptoms, the number of studies tracing somatosensory symptoms after stroke and their recovery is rather small. It is an ongoing discussion, to which extent somatosensory deficits after stroke influence patient's long-term outcome in motor and sensory performance and functional independence in activities of daily living. Modern brain imaging techniques allow for studying the impact of stroke lesion localization and size on acute and persisting clinical impairment. Here, we review the literature on somatosensory symptoms after stroke. We summarize epidemiological information on frequency and characteristics of somatosensory symptoms affecting all parts of the body in the acute and chronic stage of stroke. We further give an overview of brain imaging studies of stroke affecting the somatosensory system. Finally, we identify open questions which need to be addressed in future research and summarize the implications for clinical practice.
Assuntos
Neuroimagem/métodos , Recuperação de Função Fisiológica/fisiologia , Transtornos de Sensação/diagnóstico , Acidente Vascular Cerebral/diagnóstico , Humanos , Transtornos de Sensação/etiologia , Transtornos de Sensação/reabilitação , Acidente Vascular Cerebral/complicações , Reabilitação do Acidente Vascular CerebralRESUMO
The accurate assessment of cerebrospinal fluid opening pressure during spinal puncture provides important medical information in diagnosis, prognosis and therapy of several neurological conditions. However, purpose-specific spinal needle choice is debated. While atraumatic needles are associated with lower incidence of post-puncture headache and re-hospitalisation, some clinicians believe that they lack in accuracy of CSF opening pressure assessment. Our primary objective was to investigate different needle types on correctly assessing CSF opening pressure. We compared typical clinically utilised traumatic (0.9 mm outer diameter) and atraumatic (0.7 mm; 0.45 mm) spinal needles with regards to the assessment of the opening pressure in an experimental spinal puncture model testing experimental and cerebrospinal fluids in predefined pressures. Our goal was to measure the time until indicated pressure levels were correctly shown. Atraumatic needles of at least 0.7 mm diameter had a similar accuracy as traumatic needles without significant differences in time-to-equilibrium. These results were independent of protein and glucose concentration and the presence of haemoglobin. This study demonstrates that atraumatic needles can be used to accurately measure CSF opening pressure. This knowledge might guide clinicians in their choice of needle and help to reduce post-puncture headaches and re-hospitalisation.
RESUMO
BACKGROUND AND OBJECTIVES: It is uncertain whether there is an association of carotid plaques (CP) and flow velocities with peak-width mean diffusivity (PSMD) and white matter hyperintensities (WMH) independent of shared risk factors. We aimed to study this association controlling for biomarkers of inflammation and cardiac dysfunction as well as typical cardiovascular risk factors and spatial distribution. METHODS: We included participant from the population-based Hamburg City Health Study, recruiting citizens between 45 and 74 years of age. Medical history was obtained from structured interviews and extended laboratory tests, physical examinations, MRI of the head, echocardiography, abdominal and carotid ultrasound were performed. We performed multivariable regression analysis with PSMD, periventricular, deep, and total volume of WMH (pWMH, dWMH, tWMH) as dependent variables. PSMD was calculated as the difference between the 95th and 5th percentile of MD values on the white skeleton in standard space Volumes of WMH were determined by application of a manually trained k-nearest neighbor segmentation algorithm. WMH measured within a distance of 1 cm from the surface of the lateral ventricles were defined as pWMH, and above 1 cm as dWMH. RESULTS: 2623 participants were included. Median age was 65 years and 56% were women. Their median tWMH was 946 mm3(IQR:419, 2164), PSMD 2.24 mm2 /s x 10-4 (IQR: 2.04,2.47), peak systolic velocity (PSV) of internal carotid arteries 0.70m/sec (IQR:0.60, 0.81), and 35% had CP. Adjusted for age, sex, high-sensitive CRP, NT-proBNP, and commonly measured cardiovascular risk and systemic hemodynamic factors, both CP (B=0.15;CI:0.04, 0.26;p=0.006) and low PSV (B=-0.49; CI:-0.87,-0.11;p=0.012) were significantly associated with a higher tWMH and PSMD. Low PSV(B=-0.48;CI:-0.87,-0.1;p=0.013) was associated with pWMH, and presence of CP with pWMH (B=0.15; CI:0.04,0.26; p=0.008) and dWMH (B=0.42; CI:0.11,0.74; p<0.009). CONCLUSION: Low PSV and CP are associated with WMH and PSMD independent of cardiovascular risk factors and biomarkers of inflammation and cardiac dysfunction. This points towards pathophysiological pathways underlying both large and small vessel disease beyond the common cardiovascular risk profile. TRIAL REGISTRATION INFORMATION: The trial was submitted at www. CLINICALTRIALS: gov, under NCT03934957 on January 4 2019. The first participant was enrolled in February 2016.
RESUMO
Somatosensory deficits after ischaemic stroke are common and can occur in patients with lesions in the anterior parietal cortex and subcortical nuclei. It is less clear to what extent damage to white matter tracts within the somatosensory system may contribute to somatosensory deficits after stroke. We compared the roles of cortical damage and disruption of subcortical white matter tracts as correlates of somatosensory deficit after ischaemic stroke. Clinical and imaging data were assessed in incident stroke patients. Somatosensory deficits were measured using a standardized somatosensory test. Remote effects were quantified by projecting the MRI-based segmented stroke lesions onto a predefined atlas of white matter connectivity. Direct ischaemic damage to grey matter was computed by lesion overlap with grey matter areas. The association between lesion impact scores and sensory deficit was assessed statistically. In 101 patients, median sensory score was 188/193 (97.4%). Lesion volume was associated with somatosensory deficit, explaining 23.3% of variance. Beyond this, the stroke-induced grey and white matter disruption within a subnetwork of the postcentral, supramarginal, and transverse temporal gyri explained an additional 14% of the somatosensory outcome variability. On mutual comparison, white matter network disruption was a stronger predictor than grey matter damage. Ischaemic damage to both grey and white matter are structural correlates of acute somatosensory disturbance after ischaemic stroke. Our data suggest that white matter integrity of a somatosensory network of primary and secondary cortex is a prerequisite for normal processing of somatosensory inputs and might be considered as an additional parameter for stroke outcome prediction in the future.
Assuntos
Isquemia Encefálica , Acidente Vascular Cerebral , Substância Branca , Isquemia Encefálica/complicações , Isquemia Encefálica/diagnóstico por imagem , Substância Cinzenta/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Córtex Somatossensorial , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/diagnóstico por imagem , Substância Branca/diagnóstico por imagemRESUMO
Cerebral small vessel disease is a common disease in the older population and is recognized as a major risk factor for cognitive decline and stroke. Small vessel disease is considered a global brain disease impacting the integrity of neuronal networks resulting in disturbances of structural and functional connectivity. A core feature of cerebral small vessel disease commonly present on neuroimaging is white matter hyperintensities. We studied high-resolution resting-state EEG, leveraging source reconstruction methods, in 35 participants with varying degree of white matter hyperintensities without clinically evident cognitive impairment in an observational study. In patients with increasing white matter lesion load, global theta power was increased independently of age. Whole-brain functional connectivity revealed a disrupted network confined to the alpha band in participants with higher white matter hyperintensities lesion load. The decrease of functional connectivity was evident in long-range connections, mostly originating or terminating in the frontal lobe. Cognitive testing revealed no global cognitive impairment; however, some participants revealed deficits of executive functions that were related to larger white matter hyperintensities lesion load. In summary, participants without clinical signs of mild cognitive impairment or dementia showed oscillatory changes that were significantly related to white matter lesion load. Hence, oscillatory neuronal network changes due to white matter lesions might act as biomarker prior to clinically relevant behavioural impairment.
RESUMO
Internal carotid artery stenosis is a risk factor for ischemic stroke. Even in the absence of visible structural brain changes, patients with asymptomatic stenosis are prone to cognitive impairment. On a neuronal level, it was suggested that stenosis may lead to disturbed functional brain connectivity. If so, carotid revascularization should have an effect on hypothesized brain network disturbances. We studied functional connectivity in a motor network by resting-state electroencephalography in 12 patients with high grade asymptomatic carotid stenosis before and after interventional or surgical revascularization as compared to 23 controls. In patients with stenosis, functional connectivity of neural oscillations was significantly decreased prior and improved returning to normal connectivity after revascularization. In a subgroup of patients, also studied by contrast perfusion magnetic resonance imaging, reduced connectivity was associated with decreased regional brain perfusion reflected by increased mean transit time in the middle cerebral artery borderzone. Cognitive testing revealed only minor differences between patients and controls. In summary, we identified oscillatory connectivity changes in patients with asymptomatic carotid stenosis correlating with regional hypoperfusion, which both normalized after revascularization. Hence, electrophysiological changes might be a reversible precursor preceding macroscopic structural brain damage and behavioral impairment in patients with asymptomatic carotid stenosis.
Assuntos
Estenose das Carótidas/cirurgia , Revascularização Cerebral/métodos , Vias Neurais/fisiologia , Idoso , Estenose das Carótidas/psicologia , Circulação Cerebrovascular , Disfunção Cognitiva/etiologia , Disfunção Cognitiva/psicologia , Eletroencefalografia , Feminino , Humanos , Angiografia por Ressonância Magnética , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Artéria Cerebral Média/fisiologia , Testes Neuropsicológicos , Recuperação de Função FisiológicaRESUMO
INTRODUCTION: There is evidence suggesting a detrimental effect of asymptomatic carotid artery stenosis on cognitive function even in the absence of ischemic cerebral lesions. Hypoperfusion has been suggested as pathophysiological mechanism causing cognitive impairment. We aimed to assess cognitive performance and cerebral perfusion changes in patients with carotid artery stenosis without ischemic lesions by arterial spin labeling (ASL) and contrast enhanced (CE) perfusion MRI before and after revascularization therapy. METHODS: 17 asymptomatic patients with unilateral high-grade (≥70%) carotid artery stenosis without evidence of structural brain lesions underwent ASL and CE perfusion MRI and cognitive testing (MMSE, DemTect, Clock-Drawing Test, Trail-Making Test, Stroop Test) before and 6-8â¯weeks after revascularization therapy by endarterectomy or stenting. Multiparametric perfusion maps (ASL: cerebral blood flow (ASL-CBF), bolus arrival time (ASL-BAT); CE: cerebral blood flow (CE-CBF), mean transit time (CE-MTT), cerebral blood volume (CE-CBV)) were calculated and analyzed by vascular territory. Relative perfusion values were calculated. RESULTS: Multivariate analysis revealed a significant impact of revascularization therapy on all perfusion measures analyzed. At baseline post-hoc testing showed significant hypoperfusion in MCA borderzones as assessed by ASL-CBF, ASL-BAT, CE-MTT and CE-CBV. All perfusion alterations normalized after revascularization. We did not observe any significant correlation of cognitive test results with perfusion parameters. There was no significant change in cognitive performance after revascularization. CONCLUSION: We found evidence of traceable perfusion alterations in patients with high grade carotid artery stenosis in the absence of structural brain lesions, which proved fully reversible after revascularization therapy. In this cohort of asymptomatic patients we did not observe an association of hypoperfusion with cognitive performance.
Assuntos
Estenose das Carótidas/fisiopatologia , Estenose das Carótidas/cirurgia , Circulação Cerebrovascular/fisiologia , Disfunção Cognitiva/fisiopatologia , Angiografia por Ressonância Magnética , Procedimentos Cirúrgicos Vasculares , Idoso , Idoso de 80 Anos ou mais , Estenose das Carótidas/complicações , Estenose das Carótidas/diagnóstico por imagem , Revascularização Cerebral , Disfunção Cognitiva/etiologia , Endarterectomia das Carótidas , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , StentsRESUMO
Corticospinal tract integrity after stroke has been widely investigated through the evaluation of fibres descending from the primary motor cortex. However, about half of the corticospinal tract is composed by sub-pathways descending from premotor and parietal areas, to which damage may play a more specific role in motor impairment and recovery, particularly post-stroke. Therefore, the main aim of this study was to investigate lesion load within corticospinal tract sub-pathways as predictors of upper limb motor impairment after stroke. Motor impairment (Fugl-Meyer Upper Extremity score) was evaluated in 27 participants at one week and six months after stroke, together with other clinical and demographic data. Neuroimaging data were obtained within the first week after stroke. Univariate regression analysis indicated that among all neural correlates, lesion load within premotor fibres explained the most variance in motor impairment at six months (R2 = 0.44, p < 0.001). Multivariable regression analysis resulted in three independent, significant variables explaining motor impairment at six months; Fugl-Meyer Upper Extremity score at one week, premotor dorsal fibre lesion load at one week, and age below or above 70 years (total R2 = 0.81; p < 0.001). Early examination of premotor dorsal fibre integrity may be a promising biomarker of upper limb motor impairment after stroke.
Assuntos
Córtex Motor/patologia , Transtornos Motores/etiologia , Transtornos Motores/patologia , Acidente Vascular Cerebral/complicações , Extremidade Superior/patologia , Substância Branca/patologia , Feminino , Humanos , Masculino , Análise Multivariada , Tratos Piramidais/patologia , Análise de RegressãoAssuntos
Analgésicos/uso terapêutico , Ocitocina/farmacologia , Percepção da Dor/efeitos dos fármacos , Efeito Placebo , Administração Intranasal , Administração Tópica , Adulto , Método Duplo-Cego , Empatia , Humanos , Masculino , Ocitocina/administração & dosagem , Medição da Dor , Confiança , Adulto JovemRESUMO
This cohort study examines clinical judgment of large vessel occlusions compared with triage scales in a sample of patients admitted to the emergency department with suspicion of acute stroke.
Assuntos
Julgamento , Acidente Vascular Cerebral , Humanos , Triagem , Acidente Vascular Cerebral/diagnósticoRESUMO
BACKGROUND: Aberrant functional connectivity in brain networks associated with motor impairment after stroke is well described, but little is known about the association with somatosensory impairments. AIM: The objective of this cross-sectional observational study was to investigate the relationship between brain functional connectivity and severity of somatosensory impairments in the upper limb in the acute phase post stroke. METHODS: Nineteen first-ever stroke patients underwent resting-state functional magnetic resonance imaging (rs-fMRI) and a standardized clinical somatosensory profile assessment (exteroception and higher cortical somatosensation) in the first week post stroke. Integrity of inter- and intrahemispheric (ipsilesional and contralesional) functional connectivity of the somatosensory network was assessed between patients with severe (Em-NSA< 13/32) and mild to moderate (Em-NSA> 13/32) somatosensory impairments. RESULTS: Patients with severe somatosensory impairments displayed significantly lower functional connectivity indices in terms of interhemispheric (p = 0.001) and ipsilesional intrahemispheric (p = 0.035) connectivity compared to mildly to moderately impaired patients. Significant associations were found between the perceptual threshold of touch assessment and interhemispheric (r = -0.63) and ipsilesional (r = -0.51) network indices. Additional significant associations were found between the index of interhemispheric connectivity and light touch (r = 0.55) and stereognosis (r = 0.64) evaluation. CONCLUSION: Patients with more severe somatosensory impairments have lower inter- and ipsilesional intrahemispheric connectivity of the somatosensory network. Lower connectivity indices are related to more impaired exteroception and higher cortical somatosensation. This study highlights the importance of network integrity in terms of inter- and ipsilesional intrahemispheric connectivity for somatosensory function. Further research is needed investigating the effect of therapy on the re-establishment of these networks.
Assuntos
Braço/inervação , Distúrbios Somatossensoriais/etiologia , Acidente Vascular Cerebral/complicações , Idoso , Idoso de 80 Anos ou mais , Braço/fisiopatologia , Estudos Transversais , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Córtex Motor/diagnóstico por imagem , Córtex Motor/fisiopatologia , Rede Nervosa/fisiopatologia , Neuroimagem , Lobo Parietal/diagnóstico por imagem , Lobo Parietal/fisiopatologia , Córtex Sensório-Motor/diagnóstico por imagem , Córtex Sensório-Motor/fisiopatologia , Índice de Gravidade de Doença , Distúrbios Somatossensoriais/diagnóstico por imagem , Distúrbios Somatossensoriais/fisiopatologia , Acidente Vascular Cerebral/diagnóstico por imagemRESUMO
BACKGROUND: Proportional motor recovery in the upper limb has been investigated, indicating about 70% of the potential for recovery of motor impairment within the first months poststroke. OBJECTIVE: To investigate whether the proportional recovery rule is applicable for upper-limb somatosensory impairment and to study underlying neural correlates of impairment and outcome at 6 months. METHODS: A total of 32 patients were evaluated at 4 to 7 days and 6 months using the Erasmus MC modification of the revised Nottingham Sensory Assessment (NSA) for impairment of (1) somatosensory perception (exteroception) and (2) passive somatosensory processing (sharp/blunt discrimination and proprioception); (3) active somatosensory processing was evaluated using the stereognosis component of the NSA. Magnetic resonance imaging scans were obtained within 1 week poststroke, from which lesion load (LL) was calculated for key somatosensory tracts. RESULTS: Somatosensory perception fully recovered within 6 months. Passive and active somatosensory processing showed proportional recovery of 86% (95% CI = 79%-93%) and 69% (95% CI = 49%-89%), respectively. Patients with somatosensory impairment at 4 to 7 days showed significantly greater thalamocortical and insulo-opercular tracts (TCT and IOT) LL ( P < .05) in comparison to patients without impairment. Sensorimotor tract disruption at 4 to 7 days did not provide significant contribution above somatosensory processing score at 4 to 7 days when predicting somatosensory processing outcome at 6 months. CONCLUSIONS: Our sample of stroke patients assessed early showed full somatosensory perception but proportional passive and active somatosensory processing recovery. Disruption of both the TCT and IOT early after stroke appears to be a factor associated with somatosensory impairment but not outcome.
Assuntos
Isquemia Encefálica/fisiopatologia , Recuperação de Função Fisiológica/fisiologia , Acidente Vascular Cerebral/fisiopatologia , Percepção do Tato/fisiologia , Extremidade Superior/fisiopatologia , Idoso , Idoso de 80 Anos ou mais , Isquemia Encefálica/diagnóstico por imagem , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença , Acidente Vascular Cerebral/diagnóstico por imagem , Reabilitação do Acidente Vascular CerebralRESUMO
Failure of medical treatments can hamper responses to subsequent treatments. It has been suggested that changing the route of drug administration could reduce such negative carry-over effects, but direct evidence for this approach is lacking. We therefore investigated in 211 healthy volunteers whether changes in drug administration route reduce such carry-over effects. A positive or negative treatment history with topical analgesic treatments was induced experimentally in a mock clinical trial setting. Subsequently, a different inert drug was introduced via the same (topical) or another (oral) route of administration and its analgesic efficacy was tested. Changing the route of drug administration induced expectations of positive treatment effects in the subjects but did not actually counteract the negative carry-over effects on treatment efficacy. These findings indicate that learned carry-over effects generalize over time and across routes of drug administration-independent of conscious expectations. Other strategies are needed to prevent negative carry-over effects of treatment failure from influencing the results of subsequent treatment attempts.
Assuntos
Falha de Tratamento , Adulto , Analgésicos/administração & dosagem , Analgésicos/uso terapêutico , Vias de Administração de Medicamentos , Feminino , Humanos , Masculino , Adulto JovemRESUMO
The aim of this study was to investigate the relationship between stroke lesion location and the resulting somatosensory deficit. We studied exteroceptive and proprioceptive somatosensory symptoms and stroke lesions in 38 patients with first-ever acute stroke. The Erasmus modified Nottingham Sensory Assessment was used to clinically evaluate somatosensory functioning in the arm and hand within the first week after stroke onset. Additionally, more objective measures such as the perceptual threshold of touch and somatosensory evoked potentials were recorded. Non-parametric voxel-based lesion-symptom mapping was performed to investigate lesion contribution to different somatosensory deficits in the upper limb. Additionally, structural connectivity of brain areas that demonstrated the strongest association with somatosensory symptoms was determined, using probabilistic fiber tracking based on diffusion tensor imaging data from a healthy age-matched sample. Voxels with a significant association to somatosensory deficits were clustered in two core brain regions: the central parietal white matter, also referred to as the sensory component of the superior thalamic radiation, and the parietal operculum close to the insular cortex, representing the secondary somatosensory cortex. Our objective recordings confirmed findings from clinical assessments. Probabilistic tracking connected the first region to thalamus, internal capsule, brain stem, postcentral gyrus, cerebellum, and frontal pathways, while the second region demonstrated structural connections to thalamus, insular and primary somatosensory cortex. This study reveals that stroke lesions in the sensory fibers of the superior thalamocortical radiation and the parietal operculum are significantly associated with multiple exteroceptive and proprioceptive deficits in the arm and hand.
Assuntos
Encéfalo/patologia , Propriocepção , Limiar Sensorial , Acidente Vascular Cerebral/patologia , Acidente Vascular Cerebral/psicologia , Percepção do Tato , Idoso , Idoso de 80 Anos ou mais , Braço , Isquemia Encefálica/patologia , Isquemia Encefálica/psicologia , Imagem de Tensor de Difusão/métodos , Feminino , Mãos , Humanos , Hemorragias Intracranianas/patologia , Hemorragias Intracranianas/psicologia , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Acidente Vascular Cerebral/complicações , Substância Branca/patologiaAssuntos
Gânglios da Base/diagnóstico por imagem , Gânglios da Base/fisiopatologia , Equilíbrio Postural , Reabilitação do Acidente Vascular Cerebral , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/fisiopatologia , Imagem de Tensor de Difusão , Imagem Ecoplanar , Humanos , Projetos PilotoRESUMO
It is increasingly recognized that the efficacy of medical treatments is determined in critical part by the therapeutic context in which it is delivered. An important characteristic of that context is treatment history. We recently reported first evidence for a carry-over of treatment experience to subsequent treatment response across different treatment approaches. Here we expand on these findings by exploring the psychological and neurobiological underpinnings of the effect of treatment experience on future treatment response in an experimental model of placebo analgesia with a conditioning procedure. In a combined behavioral and neuroimaging study we experimentally induced positive or negative experiences with an analgesic treatment in two groups of healthy human subjects. Subsequently we compared responses to a second, different analgesic treatment between both groups. We found that participants with an experimentally induced negative experience with the first treatment showed a substantially reduced response to a second analgesic treatment. Intriguingly, several psychological trait variables including anxiety, depression and locus of control modulate the susceptibility for the effects of prior treatment experiences on future treatment outcome. These behavioral effects were supported by neuroimaging data which showed significant differences in brain regions encoding pain and analgesia between groups. These differences in activation patterns were present not only during the pain phase, but also already prior to painful stimulation and scaled with the individual treatment response. Our data provide behavioral and neurobiological evidence showing that the influence of treatment history transfers over time and over therapeutic approaches. Our experimental findings emphasize the careful consideration of treatment history and a strictly systematic treatment approach to avoid negative carry-over effects.