scholarly journals Relationship between fractional anisotropy and neuropsychological evaluation in sports-related concussion

Neurology ◽  
2018 ◽  
Vol 91 (23 Supplement 1) ◽  
pp. S17.1-S17
Author(s):  
Haruo Nakayama ◽  
Yu Hiramoto ◽  
Yuriko Numata ◽  
Satoshi Fujita ◽  
Nozomi Hirai ◽  
...  

ObjectiveTo evaluate the relationship between functional anisotropy (FA) and neuropsychological evaluation in concussion.MethodsDiffusion tensor MRI included FA of the Brain and neuropsychological evaluation were conducted on 10 patients with concussion who were diagnosed from April 2017 to March 2018. FA was extracted from 2 regions of interest in Corpus callosum (CC) and corticospinal tract (CT). Detailed neuropsychological testing with an emphasis on Working memory (WM) and Processing speed (PS) was also conducted. The FA value in that 2 regions were compared between the 2 groups of 5 patients (group F) who failed either in WM or PS and 5 cases (group NF) who did not admit it.ResultsMean FA values in CC and CT in the Group F were 0.70 and 0.52. Mean FA values in CC and CT in the Group NF were 0.48 and 0.55.ConclusionsOur result suggests that the FA value of CC did not explain the significant fluctuation of the neuropsychological function. However, FA value in CT were shown to explain the fluctuation of WM and PS.

2020 ◽  
Author(s):  
Owen A Williams ◽  
Andrea T Shafer ◽  
Evian Perez Rivra ◽  
Yang An ◽  
Bennett Allen Landman ◽  
...  

INTRODUCTION: Little is known about longitudinal decline in white matter (WM) microstructure and its associations with cognition in preclinical Alzheimers disease (AD). METHODS: Longitudinal diffusion tensor imaging and neuropsychological testing from 50 older adults who subsequently developed mild cognitive impairment or dementia (subsequently impaired, SI) and 200 cognitively normal controls. Rates of WM decline were compared between groups using voxel-wise linear mixed-effects models. Associations between change in WM and cognition were examined. RESULTS: SI had faster decline in fractional anisotropy (FA) in the right inferior fronto-occipital fasciculus (R.IFOF) and bilateral splenium of the corpus callosum. Decline in R.IFOF FA was related to decline in verbal memory, visuospatial ability, processing speed, and MMSE (p≤ 0.05). Decline in bilateral splenium FA was related to decline in verbal fluency, processing speed, and MMSE (p≤ 0.05). DISCUSSION: Accelerated regional WM decline is characteristic of preclinical AD and related to domain specific cognitive decline.


Neurosurgery ◽  
2011 ◽  
Vol 69 (3) ◽  
pp. 696-705 ◽  
Author(s):  
Andrea Romano ◽  
Giancarlo D'Andrea ◽  
Luigi Fausto Calabria ◽  
Valeria Coppola ◽  
Camilla Rossi Espagnet ◽  
...  

Abstract BACKGROUND: Magnetic resonance with diffusion tensor image (DTI) may be able to estimate trajectories compatible with subcortical tracts close to brain lesions. A limit of DTI is brain shifting (movement of the brain after dural opening and tumor resection). OBJECTIVE: To calculate the brain shift of trajectories compatible with the corticospinal tract (CST) in patients undergoing glioma resection and predict the shift directions of CST. METHODS: DTI was acquired in 20 patients and carried out through 12 noncollinear directions. Dedicated software “merged” all sequences acquired with tractographic processing and the whole dataset was sent to the neuronavigation system. Preoperative, after dural opening (in 11) and tumor resection (in all) DTI acquisitions were performed to evaluate CST shifting. The extent of shifting was considered as the maximum distance between the preoperative and intraoperative contours of the trajectories. RESULTS: An outward shift of CST was observed in 8 patients and an inward shift in 10 patients during surgery. In the remaining 2 patients, no intraoperative displacement was detected. Only peritumoral edema showed a statistically significant correlation with the amount of shift. In those patients in which DTI was acquired after dural opening as well (11 patients), an outward shifting of CST was evident in that phase. CONCLUSION: The use of intraoperative DTI demonstrated brain shifting of the CST. DTI evaluation of white matter tracts can be used during surgical procedures only if updated with intraoperative acquisitions.


2020 ◽  
Vol 26 (7) ◽  
pp. 633-644
Author(s):  
Cara F. Levitch ◽  
Eric McConathey ◽  
Maral Aghvinian ◽  
Mark Himmelstein ◽  
Michael L. Lipton ◽  
...  

AbstractObjective:Soccer is the most popular sport worldwide and is the only sport where athletes purposely use their head to deflect the ball during play, termed “heading” the ball. These repetitive head impacts (RHI) are associated with worse neuropsychological function; however, factors that can increase risk of injury following exposure to such head impacts have been largely unexamined. The present study provided a novel examination of the modifying role of sleep on the relationship between RHI exposure and neuropsychological function in college-age soccer players.Methods:Fifty varsity and intramural college soccer players completed questionnaires assessing recent and long-term heading exposure, a self-report measure of sleep function, and a battery of neuropsychological tests.Results:A high level of recent heading exposure was significantly associated with poorer processing speed, independent of concussion history. With reduced sleep duration, a high level of recent heading exposure was related to worse sustained attention. However, with greater hours of sleep duration, heading exposure was related to preserved neuropsychological outcome in sustained attention.Conclusions:We replicated our earlier finding of an association between recent head impact exposure and worse processing speed in an independent sample. In addition, we found that sleep may serve as a risk or protective factor for soccer players following extensive exposure to head impacts. Ultimately, this study furthers the understanding of factors impacting neuropsychological function in soccer players and provides empirical support for sleep interventions to help ensure safer soccer play and recovery from injury.


2011 ◽  
Vol 70 (suppl_2) ◽  
pp. ons290-ons299 ◽  
Author(s):  
Nobuyuki Kaneko ◽  
Warren W. Boling ◽  
Takaharu Shonai ◽  
Kazumi Ohmori ◽  
Yoshiaki Shiokawa ◽  
...  

ABSTRACT BACKGROUND: Surgery within the insula carries significant risk of morbidity, particularly hemiparesis, because of the difficulty in detecting the internal capsule boundaries. OBJECTIVE: We analyzed the anatomy of the insula and identified landmarks anticipated to facilitate surgery for intrinsic insular lesions. METHODS: Insular region anatomy was studied in 11 cadaveric brains harvested within 72 hours postmortem. MRI of the specimens was acquired using 3.0 T with T2-weighting and 25 directions of diffusion tensor imaging. Landmarks easily recognizable during surgery were identified on the surface of the insula. The interrelationships between surface landmarks and critical structures were analyzed. RESULTS: The posterior inferior insular point (PIIP) and the upper central insular point (UCIP) were newly established as landmarks on the insula. The PIIP corresponded to the obvious bend in the posterior long insular gyrus. The UCIP is the meeting point between the central insular sulcus and superior peri-insular sulcus. The corticospinal tract was identified as a high-intensity area in the posterior limb of the internal capsule on T2-weighted imaging and its course confirmed with diffusion tensor imaging tractography. The corticospinal tract took a course deep to the posterosuperior insula on T2-weighted imaging, 4.8 mm from the UCIP and 6.2 mm from the PIIP. CONCLUSION: The posterosuperior part of the insula forms the region at greatest risk to corticospinal tract injury. The PIIP and UCIP are crucial to understanding the relationship of the insula with the posterior limb of the internal capsule including the corticospinal tract.


Trauma ◽  
2020 ◽  
pp. 146040862091657
Author(s):  
Andrew Post ◽  
Eyesha Hashim ◽  
T Blaine Hoshizaki ◽  
Michael D Gilchrist ◽  
Michael D Cusimano

Introduction Currently, biomechanics has not been able to effectively predict when a mild traumatic brain injury may occur as a result of head impact. To improve prediction of brain trauma and the development of protective innovations, it is important to create an understanding of the relationship between the biomechanics of the head impact event and the structural damage incurred by the brain as a result of that event. The purpose of this research was to examine the relationship between diffusion tensor imaging measures and biomechanical characteristics of a head impact. Methods Diffusion tensor imaging was conducted on concussed subjects to identify regions of white matter structural differences. The injury event was reconstructed using physical and finite element methods to identify the biomechanical parameters of the impact as well as strain to the regions of the brain. Results A significant relationship was found between shear strain, rotational acceleration, and impact velocity on increases in radial diffusivity and mean diffusivity in the fornix. Linear acceleration was also found to have a weaker but significant relationship with a decrease in radial diffusivity in the cingulum hippocampus. Conclusion These results demonstrate that impacts resulting in high shear strains may affect radial diffusivity and mean diffusivity measures, and that impact mechanics likely have an important role in what regions may present differences in diffusion tensor imaging measures.


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