Longitudinal whole-brain analysis of multi-subject diffusion data in diffuse axonal injury.

BACKGROUND: Diffuse axonal injury occurs with high acceleration and deceleration forces in traumatic brain injury (TBI). This lesion leads to disarrangement of the neuronal network, which can result in some degree of deficiency. The Extended Glasgow Outcome Scale (GOS-E) is the primary outcome instrument for the evaluation of TBI victims. Diffusion tensor imaging (DTI) assesses white matter (WM) microstructure based on the displacement distribution of water molecules. OBJECTIVE: To investigate WM microstructure within the first year after TBI using DTI, the patient's clinical outcomes, and associations. METHODS: We scanned 20 moderate and severe TBI victims at 2 months and 1 year after the event. Imaging processing was done with the FMRIB software library; we used the tract-based spatial statistics software yielding fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) for statistical analyses. We computed the average difference between the two measures across subjects and performed a one-sample t-test and threshold-free cluster enhancement, using a corrected p-value < 0.05. Clinical outcomes were evaluated with the GOS-E. We tested for associations between outcome measures and significant mean FA clusters. RESULTS: Significant clusters of altered FA were identified anatomically using the JHU WM atlas. We found increasing spotted areas of FA with time in the right brain hemisphere and left cerebellum. Extensive regions of increased MD, RD, and AD were observed. Patients presented an excellent overall recovery. CONCLUSIONS: There were no associations between FA and outcome scores, but we cannot exclude the existence of a small to moderate association.

DTI-derived parameters differ between moderate and severe traumatic brain injury and its association with psychiatric scores.

BACKGROUND AND AIM: Diffusion tensor imaging (DTI) parameters in the corpus callosum have been suggested to be a biomarker for prognostic outcomes in individuals with diffuse axonal injury (DAI). However, differences between the DTI parameters on moderate and severe trauma in DAI over time are still unclear. A secondary goal was to study the association between the changes in the DTI parameters, anxiety, and depressive scores in DAI over time. METHODS: Twenty subjects were recruited from a neurological outpatient clinic and evaluated at 2, 6, and 12 months after the brain injury and compared to matched age and sex healthy controls regarding the DTI parameters in the corpus callosum. State-Trace Anxiety Inventory and Beck Depression Inventory were used to assess psychiatric outcomes in the TBI group over time. RESULTS: Differences were observed in the fractional anisotropy and mean diffusivity of the genu, body, and splenium of the corpus callosum between DAI and controls (p < 0.02). Differences in both parameters in the genu of the corpus callosum were also detected between patients with moderate and severe DAI (p < 0.05). There was an increase in the mean diffusivity values and the fractional anisotropy decrease in the DAI group over time (p < 0.02). There was no significant correlation between changes in the fractional anisotropy and mean diffusivity across the study and psychiatric outcomes in DAI. CONCLUSION: DTI parameters, specifically the mean diffusivity in the corpus callosum, may provide reliable characterization and quantification of differences determined by the brain injury severity. No correlation was observed with DAI parameters and the psychiatric outcome scores.

Dynamic changes in white matter following traumatic brain injury and how diffuse axonal injury relates to cognitive domain.

Objective: The goal is to evaluate longitudinally with diffusion tensor imaging (DTI) the integrity of cerebral white matter in patients with moderate and severe DAI and to correlate the DTI findings with cognitive deficits.Methods: Patients with DAI (n = 20) were scanned at three timepoints (2, 6 and 12 months) after trauma. A healthy control group (n = 20) was evaluated once with the same high-field MRI scanner. The corpus callosum (CC) and the bilateral superior longitudinal fascicles (SLFs) were assessed by deterministic tractography with ExploreDTI. A neuropschychological evaluation was also performed.Results: The CC and both SLFs demonstrated various microstructural abnormalities in between-groups comparisons. All DTI parameters demonstrated changes across time in the body of the CC, while FA (fractional anisotropy) increases were seen on both SLFs. In the splenium of the CC, progressive changes in the mean diffusivity (MD) and axial diffusivity (AD) were also observed. There was an improvement in attention and memory along time. Remarkably, DTI parameters demonstrated several correlations with the cognitive domains.Conclusions: Our findings suggest that microstructural changes in the white matter are dynamic and may be detectable by DTI throughout the first year after trauma. Likewise, patients also demonstrated improvement in some cognitive skills.

Current contribution of diffusion tensor imaging in the evaluation of diffuse axonal injury.

Traumatic brain injury (TBI) is the number one cause of death and morbidity among young adults. Moreover, survivors are frequently left with functional disabilities during the most productive years of their lives. One main aspect of TBI pathology is diffuse axonal injury, which is increasingly recognized due to its presence in 40% to 50% of all cases that require hospital admission. Diffuse axonal injury is defined as widespread axonal damage and is characterized by complete axotomy and secondary reactions due to overall axonopathy. These changes can be seen in neuroimaging studies as hemorrhagic focal areas and diffuse edema. However, the diffuse axonal injury findings are frequently under-recognized in conventional neuroimaging studies. In such scenarios, diffuse tensor imaging (DTI) plays an important role because it provides further information on white matter integrity that is not obtained with standard magnetic resonance imaging sequences. Extensive reviews concerning the physics of DTI and its use in the context of TBI patients have been published, but these issues are still hazy for many allied-health professionals. Herein, we aim to review the current contribution of diverse state-of-the-art DTI analytical methods to the understanding of diffuse axonal injury pathophysiology and prognosis, to serve as a quick reference for those interested in planning new studies and who are involved in the care of TBI victims. For this purpose, a comprehensive search in Pubmed was performed using the following keywords: "traumatic brain injury", "diffuse axonal injury", and "diffusion tensor imaging".

Current contribution of diffusion tensor imaging in the evaluation of diffuse axonal injury / Contribuição atual da imagem por tensor de difusão na avaliação da lesão axonal difusa

ABSTRACT Traumatic brain injury (TBI) is the number one cause of death and morbidity among young adults. Moreover, survivors are frequently left with functional disabilities during the most productive years of their lives. One main aspect of TBI pathology is diffuse axonal injury, which is increasingly recognized due to its presence in 40% to 50% of all cases that require hospital admission. Diffuse axonal injury is defined as widespread axonal damage and is characterized by complete axotomy and secondary reactions due to overall axonopathy. These changes can be seen in neuroimaging studies as hemorrhagic focal areas and diffuse edema. However, the diffuse axonal injury findings are frequently under-recognized in conventional neuroimaging studies. In such scenarios, diffuse tensor imaging (DTI) plays an important role because it provides further information on white matter integrity that is not obtained with standard magnetic resonance imaging sequences. Extensive reviews concerning the physics of DTI and its use in the context of TBI patients have been published, but these issues are still hazy for many allied-health professionals. Herein, we aim to review the current contribution of diverse state-of-the-art DTI analytical methods to the understanding of diffuse axonal injury pathophysiology and prognosis, to serve as a quick reference for those interested in planning new studies and who are involved in the care of TBI victims. For this purpose, a comprehensive search in Pubmed was performed using the following keywords: "traumatic brain injury", "diffuse axonal injury", and "diffusion tensor imaging".

RESUMO O traumatismo cranioencefálico (TCE) é a principal causa de morbimortalidade entre adultos jovens. Aqueles que sobrevivem são frequentemente deixados com sequelas funcionais nos anos mais produtivos de suas vidas. O principal aspecto fisiopatológico do TCE é a lesão axonial difusa (LAD), cada vez mais destacada pois está presente em 40 a 50% dos casos que necessitam de internação hospitalar. LAD é definida como a injúria axonial extensa caracterizada pela axoniotomia completa assim como pelas reações secundárias a axoniopatia, que são demonstradas por métodos de neuroimagem como áreas de edema e micro-hemorragia. Entretanto, os achados da LAD são frequentemente subestimados em estudos de neuroimagem convencional. É neste contexto que imagens por tensor de difusão (DTI) ganharam ênfase, já que permitem obter informações sobre a integridade da substância branca que não eram obtidas por sequências convencionais de ressonância magnética (RM). Existem artigos extensos sobre os fundamentos físicos e as aplicações de DTI em pacientes vítimas de TCE, no entanto, estes assuntos permanecem ainda nebulosos a alguns profissionais da área de saúde. Deste modo, propomos uma revisão didática sobre a contribuição do estado da arte de diferentes métodos analíticos de DTI no entendimento do processo da fisiopatologia e prognóstico da LAD, servindo assim como uma ferramenta acessível para aqueles interessados em planejamento de novos estudos e aqueles envolvidos no tratamento de vítimas de TCE. Uma pesquisa abrangente foi realizada no Pubmed com as seguintes palavras-chave: "traumatismo cranioencefálico", "lesão axonial difusa", "imagem por tensor de difusão".

Análise da aplicabilidade de três instrumentos de avaliação de dor em distintas unidades de atendimento: ambulatório, enfermaria e urgência / Analysis of the applicability of different pain questionnaires in three hospital settings: outpatient clinic, ward and emergency unit

OBJETIVO: Avaliar a aplicabilidade dos instrumentos de avaliação de dor em três ambientes hospitalares. METODOLOGIA: Foram estudados 60 pacientes com dor musculoesquelética atendidos no Conjunto Hospitalar de Sorocaba: enfermaria da Ortopedia, ambulatório de Reumatologia e Unidade Regional de Emergência (Pronto-socorro). QUESTIONÁRIOS: Inventário breve de dor (BPI); questionário McGill de Dor (MPQ); escala visual analógica para dor (EVA). RESULTADOS: Na urgência, houve um predomínio do gênero masculino com média de idade de 35 anos. No ambulatório, foram entrevistados 18 homens com idade média de 42 anos e duas mulheres com idade média de 55 anos. Na enfermaria, predominavam os homens com idade média de 30,7 anos. No pronto-socorro e na enfermaria, a duração foi menor para a EVA e maior para o MPQ. A duração para a EVA foi menor e não diferiu com relação aos locais. Na enfermaria e no pronto-socorro, a preferência dos pacientes recaiu pelo BPI sendo que, na enfermaria, a EVA foi segunda opção. No ambulatório, a preferência dos pacientes recaiu sobre o BPI (80 por cento) seguido do MPQ e os entrevistadores se dividiram igualmente entre esses mesmos questionários. No pronto-socorro, a preferência dos entrevistadores foi pelo BPI (40 por cento), os restantes foram divididos igualmente. Houve uma prevalência maior de concordância do que de discordância das preferências entre pacientes e entrevistadores. CONCLUSÃO: Os instrumentos multidimensionais para avaliação da dor têm limitações em sua aplicabilidade no cotidiano da assistência hospitalar à saúde.

OBJECTIVE: To assess the applicability of pain assessment instruments in three hospital settings. METHODOLOGY: This study comprised 60 patients with musculoskeletal pain cared for at the Conjunto Hospitalar de Sorocaba: orthopedic ward, Rheumatology outpatient clinic, and orthopedic emergency unit. QUESTIONNAIRES: Brief Pain Inventory (BPI); McGill Pain Questionnaire (MPQ); Visual Analogue Scale for pain (VAS). RESULTS: In the emergency unit, the male sex predominated, the mean age being 35 years. In the outpatient clinic, 18 men (mean age, 42 years) and two women (mean age, 55 years) were interviewed. In the orthopedic ward, men predominated (mean age, 30.7 years). In the orthopedic emergency unit and ward, the duration of application was shorter for VAS and longer for MPQ. The VAS duration of application was the shortest and did not differ in the three settings. In the orthopedic ward and emergency unit, patients preferred the BPI, and, at the ward, the VAS was the second option. In the outpatient clinic, the patients preferred BPI (80 percent), followed by MPQ, while the interviewers were equally divided between those same questionnaires. In the orthopedic emergency unit, the interviewers preferred the BPI (40 percent), and the remaining interviewers were equally divided between the other two instruments. There was more agreement than disagreement between the preferences of patients and interviewers. CONCLUSION: The multidimensional instruments for pain assessment have limitations regarding their applicability in daily health care activities.

Analysis of the applicability of different pain questionnaires in three hospital settings: outpatient clinic, ward and emergency unit.

OBJECTIVE: To assess the applicability of pain assessment instruments in three hospital settings. METHODOLOGY: This study comprised 60 patients with musculoskeletal pain cared for at the Conjunto Hospitalar de Sorocaba: orthopedic ward, Rheumatology outpatient clinic, and orthopedic emergency unit. QUESTIONNAIRES: Brief Pain Inventory (BPI); McGill Pain Questionnaire (MPQ); Visual Analogue Scale for pain (VAS). RESULTS: In the emergency unit, the male sex predominated, the mean age being 35 years. In the outpatient clinic, 18 men (mean age, 42 years) and two women (mean age, 55 years) were interviewed. In the orthopedic ward, men predominated (mean age, 30.7 years). In the orthopedic emergency unit and ward, the duration of application was shorter for VAS and longer for MPQ. The VAS duration of application was the shortest and did not differ in the three settings. In the orthopedic ward and emergency unit, patients preferred the BPI, and, at the ward, the VAS was the second option. In the outpatient clinic, the patients preferred BPI (80%), followed by MPQ, while the interviewers were equally divided between those same questionnaires. In the orthopedic emergency unit, the interviewers preferred the BPI (40%), and the remaining interviewers were equally divided between the other two instruments. There was more agreement than disagreement between the preferences of patients and interviewers. CONCLUSION: The multidimensional instruments for pain assessment have limitations regarding their applicability in daily health care activities.