Veterans with blast injuries have changes in brain tissue that may be apparent on imaging years later, according to data presented at the 99th Annual Meeting of the Radiological Society of North America. Researchers compared diffusion tensor imaging (DTI)-derived fractional anisotropy (FA) values in 10 veterans of Operations Iraqi Freedom and Enduring Freedom who had been diagnosed with mild traumatic brain injury with those of 10 healthy controls. The average time elapsed between the blast-induced injury and DTI scan among the patients was 51.3 months. FA values were significantly different between the two groups, and the researchers found significant correlations between FA values and attention, delayed memory, and psychomotor test scores. The results suggest that blast injury may have a long-term impact on the brain.
Among college athletes, head impact exposure may be related to white matter diffusion measures and cognition during the course of one playing season, even in the absence of diagnosed concussion, according to data published online ahead of print December 11, 2013, in Neurology. Researchers prospectively studied 79 noncontact sport athletes and 80 nonconcussed varsity football and ice hockey players who wore helmets that recorded the acceleration-time history of the head following impact. Mean diffusivity (MD) in the corpus callosum was significantly different between groups. Measures of head impact exposure correlated with white matter diffusivity measures in the corpus callosum, amygdala, cerebellar white matter, hippocampus, and thalamus. The magnitude of change in corpus callosum MD postseason was associated with poorer performance on a measure of verbal learning and memory.
Among veterans, traumatic brain injury (TBI) during the most recent deployment is the strongest predictor of postdeployment symptoms of post-traumatic stress disorder (PTSD), even when accounting for predeployment symptoms, prior TBI, and combat intensity, according to research published online ahead of print December 11, 2013, in JAMA Psychiatry. A total of 1,648 active-duty Marine and Navy servicemen underwent clinical interviews and completed self-assessments approximately one month before a seven-month deployment and three to six months after deployment. At the predeployment assessment, 56.8% of participants reported prior TBI. At postdeployment assessment, 19.8% reported sustaining TBI between predeployment and postdeployment assessments. Probability of PTSD was highest for participants with severe predeployment symptoms, high combat intensity, and deployment-related TBI. TBI doubled the PTSD rates for participants with less severe predeployment PTSD symptoms.
Fidgetin inhibition could promote tissue regeneration and repair the broken cell connections that occur in spinal cord injury and other conditions, according to research presented at the 2013 Annual Meeting of the American Society for Cell Biology. Fidgetin prunes unstable microtubule scaffolding in cells, as well as unneeded connections in the neuronal network as the latter grows. Researchers used a novel nanoparticle technology to block fidgetin in the injured nerves of adult rats. The nanoparticles were infused with small interfering RNA that bound the messenger RNA (mRNA) transcribed from the fidgetin gene. The mRNA for fidgetin was not translated, and the cell did not produce fidgetin. Blocking fidgetin restarted tissue growth in the animals. The technique could benefit patients with myocardial infarction or chronic cutaneous wounds.
Deep brain stimulation may improve driving ability for people with Parkinson’s disease, according to a study published online ahead of print December 18, 2013, in Neurology. Investigators studied 23 people who had deep brain stimulators, 21 people with Parkinson’s disease without stimulators, and 21 healthy individuals. Participants were tested with a driving simulator. Individuals with stimulators completed the test once with the stimulator on, once with it off, and once with the stimulator off after receiving levodopa. People with Parkinson’s disease without stimulators performed worse than controls in almost every category. People with stimulators did not perform significantly worse than the controls. Participants with stimulators had an average of 3.8 slight driving errors on the test, compared with 7.5 for the controls and 11.4 for people with Parkinson’s disease without stimulators.
Gadolinium-based contrast medium (Gd-CM) may be associated with abnormalities on brain MRI, according to research published online ahead of print December 17, 2013, in Radiology. Researchers compared unenhanced T1-weighted MR images of 19 patients who had undergone six or more contrast-enhanced brain scans with images of 16 people who had received six or fewer unenhanced scans. The hyperintensity of the dentate nucleus and globus pallidus correlated with the number of Gd-CM administrations. Hyperintensity in the dentate nucleus and globus pallidus on unenhanced MRI may be a consequence of the number of previous Gd-CM administrations, according to the researchers. Because gadolinium has a high signal intensity in the body, the data suggest that the toxic gadolinium component remains in the body in patients with normal renal function.