There are time-dependent improvements in visual memory in patients with DAI. Neuroplasticity in the 1st months after trauma provides an opportunity for visuospatial memory learning. The present findings may be useful to formulate management plans for long-term TBI rehabilitation.

Our findings suggest that MHL may be a predictor of WMV reduction but cannot predict EF or EVM in DAI. Brain atrophy progresses over time, but patients showed better EF and EVM in some of the tests, which could be due to neuroplasticity.

We present a case report of motor and cognitive disorders in a 36-year-old woman with a history of twelve years of heavy alcohol abuse. The patient presented depressive symptoms over the course of one year after a loss in the family, evolving with ataxia, bradykinesia and choreiform movements. Progressive cognitive decline, sleep alterations and myalgia were also reported during the course of disease evolution. Physical examination revealed spastic paraparesis with fixed flexion of the hips and knees with important pain upon extension of these joints. Initial investigation suggested the diagnosis of thiamine deficiency by brain magnetic resonance imaging (MRI).

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Background: Diffuse axonal injury (DAI) is a frequent mechanism of traumatic brain injury (TBI) that triggers a sequence of parenchymal changes that progresses from focal axonal shear injuries up to inflammatory response and delayed axonal disconnection. Objective:The main purpose of this study is to evaluate changes in the axonal/myelinic content and the brain volume up to 12 months after TBI and to correlate these changes with neuropsychological results. Methods: Patients with DAI (n = 25) were scanned at three time points after trauma (2, 6, and 12 months), and the total brain volume (TBV), gray matter volume, and white matter volume (WMV) were calculated in each time point. The magnetization transfer ratio (MTR) for the total brain (TB MTR), gray matter (GM MTR), and white matter (WM MTR) was also quantified. In addition, Hopkins verbal learning test (HVLT), Trail Making Test (TMT), and Rey-Osterrieth Complex Figure test were performed at 6 and 12 months after the trauma.Results: There was a significant reduction in the mean TBV, WMV, TB MTR, GM MTR, and WM MTR between time points 1 and 3 (p < .05). There was also a significant difference in HVLT-immediate, TMT-A, and TMT-B scores between time points 2 and 3. The MTR decline correlated more with the cognitive dysfunction than the volume reduction. Conclusion:A progressive axonal/myelinic rarefaction and volume loss were characterized, especially in the white matter (WM) up to 1 year after the trauma. Despite that, specific neuropsychological tests revealed that patients' episodic verbal memory, attention, and executive function improved during the study. The current findings may be valuable in developing long-term TBI rehabilitation management programs.

No abstract

Magnetic resonance guided high intensity focused ultrasound thalamotomy is an Food and Drug Administration-approved treatment for Essential Tremor. The target, the Ventral Intermediate Nucleus of the thalamus, is not visualized on standard, anatomic MRI sequences. Several recent reports have used Diffusion Tensor Imaging for targeting the Dentato-Rubro-Thalamic-Tract. There is considerable variability in fiber tracking algorithms and what fibers are tracked. Targeting discrete white matter tracts with magnetic resonance guided high intensity focused ultrasound is an emerging precision medicine technique that has the promise to improve patient outcomes and reduce treatment times. We provide a technical overview and clinical benefits of our novel, easily implemented advanced tractography method: four-tract tractography. Our method is novel because it targets both the decussating and non-decussating Dentato-Rubro-Thalamic-Tracts while avoiding the medial lemniscus and corticospinal tracts. Our method utilizes Food and Drug Administration-approved software and is easily implementable into existing workflows. Initial experience using this approach suggests that it improves patient outcomes by reducing the incidence of adverse effects.

MRI-guided high-intensity focused ultrasound thalamotomy is an incisionless therapy for essential tremor. To reduce adverse effects, the field has migrated to treating at approximately 2 mm above the anterior commissure-posterior commissure plane. We perform MRI-guided high intensity focused ultrasound with an advanced imaging targeting technique, four tract tractography. Four tract tractography uses diffusion tensor imaging to identify the critical white matter targets for tremor control, the decussating and non-decussating dentatorubrothalamic tracts, while the corticospinal tract and medial lemniscus are identified to be avoided. In some patients, four tract tractography identified a risk of damaging the medial lemniscus or corticospinal tract if treating at 2 mm superior to the anterior commissure-posterior commissure plane. In these patients, we chose to target 1.2-1.5 mm superior to the anterior commissure-posterior commissure plane. In these patients, post-operative imaging revealed that the focused ultrasound lesion extended into the posterior subthalamic area. This study sought to determine if patients with focused ultrasound lesions that extend into the posterior subthalamic area have greater tremor improvement than those without. 20 essential tremor patients underwent MRI-guided high intensity focused ultrasound and were retrospectively classified into two groups. Group 1 included patients with extension of the thalamic focused ultrasound lesion into the posterior subthalamic area. Group 2 included patients without extension of the thalamic focused ultrasound lesion into the posterior subthalamic area. For each patient, the percent change in postural tremor, kinetic tremor, and Archimedes spiral scores were calculated between baseline and a three-month follow-up. Two-tailed Wilcoxon rank sum tests were used to compare improvement in tremor scores, total number of sonications, thermal dose to achieve initial tremor response, and skull density ratio between groups. Group 1 had significantly greater postural, kinetic, and Archimedes spiral score percent improvement than Group 2 (p-values: 5.41 × 10−5, 4.87 × 10−4, and 5.41 × 10−5, respectively). Group 1 also required significantly fewer total sonications to control the tremor and a significantly lower thermal dose to achieve tremor response (p-values: 6.60 × 10−4 and 1.08 × 10−5, respectively). No significant group differences in skull density ratio were observed (p-value = 1.0). We do not advocate directly targeting the posterior subthalamic area with MRI-guided high-intensity focused ultrasound because the shape of the focused ultrasound lesion can result in a high risk of adverse effects. However, when focused ultrasound lesions naturally extend from the thalamus into the posterior subthalamic area, they provide greater tremor control than those that only involve the thalamus.