Functional abnormalities in normally appearing athletes following mild traumatic brain injury: a functional MRI study
- 1.4k Downloads
Memory problems are one of the most common symptoms of sport-related mild traumatic brain injury (MTBI), known as concussion. Surprisingly, little research has examined spatial memory in concussed athletes given its importance in athletic environments. Here, we combine functional magnetic resonance imaging (fMRI) with a virtual reality (VR) paradigm designed to investigate the possibility of residual functional deficits in recently concussed but asymptomatic individuals. Specifically, we report performance of spatial memory navigation tasks in a VR environment and fMRI data in 15 athletes suffering from MTBI and 15 neurologically normal, athletically active age matched controls. No differences in performance were observed between these two groups of subjects in terms of success rate (94 and 92%) and time to complete the spatial memory navigation tasks (mean = 19.5 and 19.7 s). Whole brain analysis revealed that similar brain activation patterns were observed during both encoding and retrieval among the groups. However, concussed athletes showed larger cortical networks with additional increases in activity outside of the shared region of interest (ROI) during encoding. Quantitative analysis of blood oxygen level dependent (BOLD) signal revealed that concussed individuals had a significantly larger cluster size during encoding at parietal cortex, right dorsolateral prefrontal cortex, and right hippocampus. In addition, there was a significantly larger BOLD signal percent change at the right hippocampus. Neither cluster size nor BOLD signal percent change at shared ROIs was different between groups during retrieval. These major findings are discussed with respect to current hypotheses regarding the neural mechanism responsible for alteration of brain functions in a clinical setting.
KeywordsConcussion fMRI Virtual reality Spatial memory Spatial navigation
This study was supported by NIH Grant RO1 NS056227-01A2 “Identification of Athletes at Risk for Traumatic Brain Injury” awarded to Dr. Slobounov, PI. We would like to thank Elena Slobounov for VR programming and Dr. Susan Lemieux for fMRI design development. All human studies have been approved by the The Pennsylvania State University IRB and all subjects gave their informed consent prior to their inclusion in the study.
- Brett M, Anton J-L, Valabregue R, Poline J-B (2002) Region of interest analysis using an SPM toolbox [abstract]. Presented at the 8th International Conference on Functional Mapping of the Human Brain, 2–6 June, Sendai, Japan. Available on CD-ROM in Neuroimage 16(2)Google Scholar
- Cao C, Slobounov S (2009) Alteration of cortical functional connectivity as a result of traumatic brain injury revealed by graph theory, ICA and sLORETA analyses of EEG signals. IEEE (in press)Google Scholar
- Dennis N, Cabeza R (2007) Neuroimaging of healthy cognitive aging. In: Craik F, Salthouse T (eds) The handbook of aging and cognition, 3rd edn. Psychology Press, New YorkGoogle Scholar
- Guskiewicz K (2003) Assessment of postural stability following sport-related concussion. Curr Sport Med Rep 2(1):24–30Google Scholar
- Kessels RPC, de Haan EHF, Kapelle LJ, Postma A (2000b) Varieties of human spatial; memory: a meta-analysis of the effects of hippocampal lesions. Brain Res Rev 10:295–303Google Scholar
- Lovell MR, Pardini JE, Welling J, Collins MW, Bakal J, Lazar N, Roush R, Eddy WF, Becker JT (2007) Functional brain abnormalities are related to clinical recovery and time to return-to-play in athletes. Neurosurgery 61(2):359–360Google Scholar
- Maldjian JA, Laurienti PJ, Burdette JB, Kraft RA (2003) An automated method for neuroanatomic and cytoarchitectonic atlas-based interrogation of fMRI data sets. Neuroimage 19:1233–1239Google Scholar
- Rosenbaum R, Furey M, Horwitz B, Grady C (2008) Altered connectivity among emotion-related brain regions during short-term memory in Alzheimer’s disease. Neurobiol Aging 10:724–741Google Scholar
- Schrader H, Mickrevičiene D, Gleizniene R, Jakstiene S, Surkiene D, Stovner L, Obelieniene D (2009) Magnetic resonance imaging after most common form of concussion. BMC Med Imag 9(11) (this article is available from: http://www.biomedcentral.com/1471-2342/9/11)
- Tollard E, Galanaud D, Perlbarg V, Sanchez-Pena P, Le Fur Y, Abdennour L, Cozzone P, Lehericy S, Chiras J, Puybasset L (2009) Experience of diffusion tensor imaging and 1H spectroscopy for outcome prediction in severe traumatic brain injury: preliminary results. Crit Care Med 37(4):1448–1455CrossRefPubMedGoogle Scholar
- Wirth W, Hartmann T, Boecking S, Vorderer P, Klimmt C, Schramm H et al (2007) A process model of the formation of spatial presence experience. Med Psychol 9:493–525Google Scholar