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OBJECTIVE: To identify amygdalar volumetric differences associated with posttraumatic stress disorder (PTSD) in individuals with comorbid mild traumatic brain injury (mTBI) compared with those with mTBI-only and to examine the effects of intracranial volume (ICV) on amygdala volumetric measures. SETTING: Marine Corps Base and VA Healthcare System. PARTICIPANTS: A cohort of veterans and active-duty military personnel with combat-related mTBI (N = 89). DESIGN: Twenty-nine participants were identified with comorbid PTSD and mTBI. The remaining 60 formed the mTBI-only control group. Structural images of brains were obtained with a 1.5-T MRI scanner using a T1-weighted 3D-IR-FSPGR pulse sequence. Automatic segmentation was performed in Freesurfer. MAIN MEASURES: Amygdala volumes with/without normalizations to ICV. RESULTS: The comorbid mTBI/PTSD group had significantly larger amygdala volumes, when normalized to ICV, compared with the mTBI-only group. The right and left amygdala volumes after normalization to ICV were 0.122% ± 0.012% and 0.118% ± 0.011%, respectively, in the comorbid group compared with 0.115% ± 0.012% and 0.112% ± 0.009%, respectively, in the mTBI-only group (corrected P < .05). CONCLUSIONS: The ICV normalization analysis performed here may resolve previous literature discrepancies. This is an intriguing structural finding, given the role of the amygdala in the challenging neuroemotive symptoms witnessed in casualties of combat-related mTBI and PTSD.
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Tonsila do Cerebelo/patologia , Concussão Encefálica/patologia , Distúrbios de Guerra/patologia , Militares , Transtornos de Estresse Pós-Traumáticos/patologia , Veteranos , Adulto , Concussão Encefálica/psicologia , Estudos de Casos e Controles , Distúrbios de Guerra/complicações , Feminino , Humanos , Masculino , Tamanho do Órgão , Transtornos de Estresse Pós-Traumáticos/etiologiaRESUMO
BACKGROUND: Mild traumatic brain injury (mTBI) is a leading cause of sustained impairments in military service members, Veterans, and civilians. However, few treatments are available for mTBI, partially because the mechanism of persistent mTBI deficits is not fully understood. METHODS: We used magnetoencephalography (MEG) to investigate neuronal changes in individuals with mTBI following a passive neurofeedback-based treatment programme called IASIS. This programme involved applying low-intensity pulses using transcranial electrical stimulation (LIP-tES) with electroencephalography monitoring. Study participants included six individuals with mTBI and persistent post-concussive symptoms (PCS). MEG exams were performed at baseline and follow-up to evaluate the effect of IASIS on brain functioning. RESULTS: At the baseline MEG exam, all participants had abnormal slow-waves. In the follow-up MEG exam, the participants showed significantly reduced abnormal slow-waves with an average reduction of 53.6 ± 24.6% in slow-wave total score. The participants also showed significant reduction of PCS scores after IASIS treatment, with an average reduction of 52.76 ± 26.4% in PCS total score. CONCLUSIONS: The present study demonstrates, for the first time, the neuroimaging-based documentation of the effect of LIP-tES treatment on brain functioning in mTBI. The mechanisms of LIP-tES treatment are discussed, with an emphasis on LIP-tES's potentiation of the mTBI healing process.
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Lesões Encefálicas Traumáticas/diagnóstico por imagem , Lesões Encefálicas Traumáticas/terapia , Imageamento por Ressonância Magnética , Magnetoencefalografia , Estimulação Transcraniana por Corrente Contínua , Adulto , Eletroencefalografia , Feminino , Análise de Fourier , Humanos , Masculino , Testes Neuropsicológicos , Projetos Piloto , Síndrome Pós-Concussão/diagnóstico , Inquéritos e Questionários , VeteranosRESUMO
PURPOSE: The study aims to (1) examine the spatiotemporal map of magnetoencephalography-evoked responses during an Auditory Memory Retrieval and Silent Repeating (AMRSR) task, and determine the hemispheric dominance for language, and (2) evaluate the accuracy of the AMRSR task in Wernicke and Broca area localization. METHODS: In 30 patients with brain tumors and/or epilepsies, the AMRSR task was used to evoke magnetoencephalography responses. We applied Fast VEctor-based Spatial-Temporal Analyses with minimum L1-norm source imaging method to the magnetoencephalography responses for localizing the brain areas evoked by the AMRSR task. RESULTS: The Fast-VEctor-based Spatial-Temporal Analysis found consistent activation in the posterior superior temporal gyrus around 300 to 500 ms, and another activation in the frontal cortex (pars opercularis and/or pars triangularis) around 600 to 900 ms, which were localized to the Wernicke area (BA 22) and Broca area (BA 44 and BA 45), respectively. The language-dominant hemispheric laterization elicited by the AMRSR task was comparable with the result from an Auditory Dichotic task result given to the same patient, with the exception that AMRSR is more sensitive on bilateral language laterization cases on finding the Wernicke and Broca areas. CONCLUSIONS: For all patients who successfully finished the AMRSR task, Fast-VEctor-based Spatial-Temporal Analysis could establish accurate and robust localizations of Broca and Wernicke area and determine hemispheric dominance. For subjects with normal auditory functionality, the AMRSR paradigm evaluation showed significant promise in providing reliable assessments of cerebral language dominance and language network localization.
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Introduction The motivation to improve accuracy and reduce complication rates in spinal surgery has driven great advancements in robotic surgical systems, with the primary difference between the newer generation and older generation models being the presence of an optical camera and multijointed arm. This study compares accuracy and complication rates of pedicle screw placement in older versus newer generation robotic systems reported in the literature. Methods We performed a systemic review and meta-analysis describing outcomes of pedicle screw placement with robotic spine surgery. We assessed the robustness of these findings by quantifying levels of cross-study heterogeneity and publication bias. Finally, we performed meta-regression to test for associations between pedicle screw accuracy and older versus newer generation robotic spine system usage. Results Average pedicle screw placement accuracy rates for old and new generation robotic platforms were 97 and 99%, respectively. Use of new generation robots was significantly associated with improved pedicle screw placement accuracy ( p = 0.03). Conclusion Accuracy of pedicle screw placement was high across all generations of robotic surgical systems. However, newer generation robots were shown to be significantly associated with accurate pedicle screw placement, showing the benefits of upgrading robotic systems with a real-time optical camera and multijointed arm.
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OBJECTIVE: Localizing expressive language function has been challenging using the conventional magnetoencephalography (MEG) source modeling methods. The present MEG study presents a new accurate and precise approach in localizing the language areas using a high-resolution MEG source imaging method. METHODS: In 32 patients with brain tumors and/or epilepsies, an object-naming task was used to evoke MEG responses. Our Fast-VESTAL source imaging method was then applied to the MEG data in order to localize the brain areas evoked by the object-naming task. RESULTS: The Fast-VESTAL results showed that Broca's area was accurately localized to the pars opercularis (BA 44) and/or the pars triangularis (BA 45) in all patients. Fast-VESTAL also accurately localized Wernicke's area to the posterior aspect of the superior temporal gyri in BA 22, as well as several additional brain areas. Furthermore, we found that the latency of the main peak of the response in Wernicke's area was significantly earlier than that of Broca's area. CONCLUSION: In all patients, Fast-VESTAL analysis established accurate and precise localizations of Broca's area, as well as other language areas. The responses in Wernicke's area were also shown to significantly precede those of Broca's area. SIGNIFICANCE: The present study demonstrates that using Fast-VESTAL, MEG can serve as an accurate and reliable functional imaging tool for presurgical mapping of language functions in patients with brain tumors and/or epilepsies.