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. 2005 Nov;39(11):805–811. doi: 10.1136/bjsm.2004.015909

Detecting altered postural control after cerebral concussion in athletes with normal postural stability

J Cavanaugh 1, K Guskiewicz 1, C Giuliani 1, S Marshall 1, V Mercer 1, N Stergiou 1
PMCID: PMC1725054  PMID: 16244188

Abstract

Objective: To determine if approximate entropy (ApEn), a regularity statistic from non-linear dynamics, could detect changes in postural control during quiet standing in athletes with normal postural stability after cerebral concussion.

Methods: The study was a retrospective, case series analysis of centre of pressure (COP) data collected during the Sensory Organization Test (SOT) from NCAA Division I (USA) athletes prior to and within 48 h after injury. Subjects were 21 male and six female athletes from a variety of sports who sustained a cerebral concussion between 1997 and 2003. After injury, athletes displayed normal postural stability equivalent to preseason levels. For comparison, COP data also were collected from 15 male and 15 female healthy non-athletes on two occasions. ApEn values were calculated for COP anterior-posterior (AP) and medial-lateral (ML) time series.

Results: Compared to healthy subjects, COP oscillations among athletes generally became more regular (lower ApEn value) after injury despite the absence of postural instability. For AP time series, declines in ApEn values were much larger in SOT conditions 1 and 2 (approximately three times as large as the standard error of the mean) than for all other conditions. For ML time series, ApEn values declined after injury in all sensory conditions (F1,55 = 6.36, p = 0.02).

Conclusions: Athletes who demonstrated normal postural stability after concussion nonetheless displayed subtle changes in postural control. Changes in ApEn may have represented a clinically abnormal finding. ApEn analysis of COP oscillations may be a valuable supplement to existing concussion assessment protocols for athletes.

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Selected References

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  1. Bodfish J. W., Parker D. E., Lewis M. H., Sprague R. L., Newell K. M. Stereotypy and motor control: differences in the postural stability dynamics of persons with stereotyped and dyskinetic movement disorders. Am J Ment Retard. 2001 Mar;106(2):123–134. doi: 10.1352/0895-8017(2001)106<0123:SAMCDI>2.0.CO;2. [DOI] [PubMed] [Google Scholar]
  2. Collins J. J., De Luca C. J. Open-loop and closed-loop control of posture: a random-walk analysis of center-of-pressure trajectories. Exp Brain Res. 1993;95(2):308–318. doi: 10.1007/BF00229788. [DOI] [PubMed] [Google Scholar]
  3. Goldie P. A., Bach T. M., Evans O. M. Force platform measures for evaluating postural control: reliability and validity. Arch Phys Med Rehabil. 1989 Jul;70(7):510–517. [PubMed] [Google Scholar]
  4. Guskiewicz K. M., Perrin D. H., Gansneder B. M. Effect of mild head injury on postural stability in athletes. J Athl Train. 1996 Oct;31(4):300–306. [PMC free article] [PubMed] [Google Scholar]
  5. Guskiewicz K. M., Riemann B. L., Perrin D. H., Nashner L. M. Alternative approaches to the assessment of mild head injury in athletes. Med Sci Sports Exerc. 1997 Jul;29(7 Suppl):S213–S221. doi: 10.1097/00005768-199707001-00003. [DOI] [PubMed] [Google Scholar]
  6. Guskiewicz Kevin M., McCrea Michael, Marshall Stephen W., Cantu Robert C., Randolph Christopher, Barr William, Onate James A., Kelly James P. Cumulative effects associated with recurrent concussion in collegiate football players: the NCAA Concussion Study. JAMA. 2003 Nov 19;290(19):2549–2555. doi: 10.1001/jama.290.19.2549. [DOI] [PubMed] [Google Scholar]
  7. Guskiewicz Kevin M., Ross Scott E., Marshall Stephen W. Postural Stability and Neuropsychological Deficits After Concussion in Collegiate Athletes. J Athl Train. 2001 Sep;36(3):263–273. [PMC free article] [PubMed] [Google Scholar]
  8. Harbourne Regina T., Stergiou Nicholas. Nonlinear analysis of the development of sitting postural control. Dev Psychobiol. 2003 May;42(4):368–377. doi: 10.1002/dev.10110. [DOI] [PubMed] [Google Scholar]
  9. Kelly J. P., Nichols J. S., Filley C. M., Lillehei K. O., Rubinstein D., Kleinschmidt-DeMasters B. K. Concussion in sports. Guidelines for the prevention of catastrophic outcome. JAMA. 1991 Nov 27;266(20):2867–2869. doi: 10.1001/jama.266.20.2867. [DOI] [PubMed] [Google Scholar]
  10. McCrea Michael, Guskiewicz Kevin M., Marshall Stephen W., Barr William, Randolph Christopher, Cantu Robert C., Onate James A., Yang Jingzhen, Kelly James P. Acute effects and recovery time following concussion in collegiate football players: the NCAA Concussion Study. JAMA. 2003 Nov 19;290(19):2556–2563. doi: 10.1001/jama.290.19.2556. [DOI] [PubMed] [Google Scholar]
  11. McCrory P., Johnston K. M., Mohtadi N. G., Meeuwisse W. Evidence-based review of sport-related concussion: basic science. Clin J Sport Med. 2001 Jul;11(3):160–165. doi: 10.1097/00042752-200107000-00006. [DOI] [PubMed] [Google Scholar]
  12. Pincus S. M. Approximate entropy as a measure of system complexity. Proc Natl Acad Sci U S A. 1991 Mar 15;88(6):2297–2301. doi: 10.1073/pnas.88.6.2297. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Pincus S. M., Gladstone I. M., Ehrenkranz R. A. A regularity statistic for medical data analysis. J Clin Monit. 1991 Oct;7(4):335–345. doi: 10.1007/BF01619355. [DOI] [PubMed] [Google Scholar]
  14. Pincus S. M., Goldberger A. L. Physiological time-series analysis: what does regularity quantify? Am J Physiol. 1994 Apr;266(4 Pt 2):H1643–H1656. doi: 10.1152/ajpheart.1994.266.4.H1643. [DOI] [PubMed] [Google Scholar]
  15. Powell John W. Cerebral Concussion: Causes, Effects, and Risks in Sports. J Athl Train. 2001 Sep;36(3):307–311. [PMC free article] [PubMed] [Google Scholar]
  16. Riemann B. L., Guskiewicz K. M. Effects of mild head injury on postural stability as measured through clinical balance testing. J Athl Train. 2000 Jan;35(1):19–25. [PMC free article] [PubMed] [Google Scholar]
  17. Sabatini A. M. Analysis of postural sway using entropy measures of signal complexity. Med Biol Eng Comput. 2000 Nov;38(6):617–624. doi: 10.1007/BF02344866. [DOI] [PubMed] [Google Scholar]
  18. Salenius Stephan, Hari Riitta. Synchronous cortical oscillatory activity during motor action. Curr Opin Neurobiol. 2003 Dec;13(6):678–684. doi: 10.1016/j.conb.2003.10.008. [DOI] [PubMed] [Google Scholar]
  19. Schiff S. J., Sauer T., Chang T. Discriminating deterministic versus stochastic dynamics in neuronal activity. Integr Physiol Behav Sci. 1994 Jul-Sep;29(3):246–261. doi: 10.1007/BF02691329. [DOI] [PubMed] [Google Scholar]
  20. Shaw Nigel A. The neurophysiology of concussion. Prog Neurobiol. 2002 Jul;67(4):281–344. doi: 10.1016/s0301-0082(02)00018-7. [DOI] [PubMed] [Google Scholar]
  21. Theiler J., Rapp P. E. Re-examination of the evidence for low-dimensional, nonlinear structure in the human electroencephalogram. Electroencephalogr Clin Neurophysiol. 1996 Mar;98(3):213–222. doi: 10.1016/0013-4694(95)00240-5. [DOI] [PubMed] [Google Scholar]
  22. Thurman D. J., Branche C. M., Sniezek J. E. The epidemiology of sports-related traumatic brain injuries in the United States: recent developments. J Head Trauma Rehabil. 1998 Apr;13(2):1–8. doi: 10.1097/00001199-199804000-00003. [DOI] [PubMed] [Google Scholar]

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