Return to play in athletes with spinal cord concussion: a systematic literature review.

Editorial Review

Return to play in athletes with spinal cord concussion: a systematic

literature review.

Narihito Nagoshi, Lindsay Tetreault, Hiroaki Nakashima, Aria Nouri, Michael G. Fehlings

The Spine Journal 2016

JACO Editorial Reviewer: Brandon Steele DC, FACO

Published: March 2017

Journal of the Academy of Chiropractic Orthopedists

March 2017, Volume 14, Issue 1

The original article copyright belongs to the original publisher. This review is available from: http://www.dcorthoacademy.com © 2017 Steele and the Academy of Chiropractic Orthopedists. This is an Open Access article which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Authors’ Abstract:

Background: The study aimed to evaluate whether spinal cord concussion (SCC) patients can safely return to play sports and if there are factors that can predict SCC recurrence or the development of a spinal cord injury (SCI). Although SCC is a reversible neurologic disturbance of spinal cord function, its management and the implications for return to play are controversial.

Methods: We conducted a systematic search of the literature using the keywords Cervical Spine AND Sports AND Injuries in six databases. We examined return to play in patients (1) without stenosis, (2) with stenosis, and (3) who underwent single-level anterior cervical discectomy and fusion (ACDF). We also investigated predictors for the risk of SCC recurrence or SCI.

Results: We identified 3,655 unique citations, 16 of which met our inclusion criteria. The included studies were case-control studies or case series and reports. Two studies reported on patients without stenosis: pediatric cases returned without recurrence, whereas an adult case experienced recurrent SCC after returning to play. Seven studies described patients with stenosis. These studies included cases with and without recurrence after return to play, as well as patients who suffered SCI with permanent neurologic deficits. Three studies reported on patients who underwent an ACDF. Although some patients played after surgery without problems, several patients experienced recurrent SCC due to herniation at levels adjacent to the surgical sites. With respect to important predictors, a greater frequency of patients who experienced recurrence of symptoms or SCI following return to play had a “long” duration of symptoms (>24 hours; 36.36%) compared with those who were problem-free (11.11%; p=.0311).

Conclusions: There is limited evidence on current practice standards for return to play following SCC and important risk factors for SCC recurrence or SCI. Because of small sample sizes, future prospective multicenter studies are needed to determine important predictive factors of poor outcomes following return to play after SCC.

Clinical Relevance: Clinicians should evaluate the risks, symptom duration, age, and pre-existing conditions before football players are allowed to return to play. Nagoshi et al. reviews four major questions that affect patient prognosis after SCC.

JACO Editorial Summary:

  1. The article originates from authors at the University of Toronto, Keio University School of Medicine and Nagoya University Graduate School of Medicine.
  2. SCC is a reversible transient disturbance of the cord membrane usually due to sub-maximal stretching of the nervous system secondary to trauma.
  3. Symptoms usually resolve within 48 hours including motor weakness, burning, paresthesia, and/or paralysis. Complete recovery is expected in most athletes.
  4. This study aims to conduct a systematic review of the literature to (1) evaluate the criteria for return to contact sports after SCC, and (2) determine whether demographic, imaging, and surgical factors are predictors of SCC recurrence or SCI.
  5. This study attempts to answer these four questions.
    • Q1. Can SCC patients without canal stenosis or disc herniation return to play?
    • Q2. Can SCC patients with canal stenosis or disc herniation return to play?
    • Q3. Can SCC patients return to play after single-level anterior cervical discectomy and fusion (ACDF)?
    • Q4. After return to play, are there clinical, sports-related, imaging, or surgical factors that predict recurrence of SCC or SCI?

Results:

  • Q1. Upon review of the included studies all patients returned to play with no further spinal cord injury. There were re-exacerbations of spinal cord concussions without long-term symptoms in two cases.
  • Q2. In the case studies reported: most patients who returned to play after SCC with cervical stenosis did not have any serious complications. However, two studies reported spinal cord injury with permanent neurologic deficit following return to play in athletes with previous episodes of SCC.
  • Q3. Patients undergoing a single level ACDF and returned to play yielded mixed results. All studies were case series or reports limiting their statistical power. Many of these players that returned to play developed reoccurrence of symptoms with stenosis and/or herniation at adjacent levels. Others either retired or did not return to play.
  • Q4. One study by Torg demonstrated three factors predicting reoccurrence of cord injury or concussion. 1. Smaller spinal canal to vertebral body ratio. 2. Smaller disc–level diameter. 3. Less physical space available for the spinal cord. Younger patients with a longer duration of symptoms from initial injury also demonstrated the greatest risk for re-injury.

Summary:

There is a high risk of selection and information bias due to the limited amount of studies meeting the inclusion criteria. Given a low number of studied occurrences on return to play following SCC it would be difficult to draw concretes conclusions. However, this information may become useful as a guide to patient prognosis and education following a spinal cord concussion. Four main points are from this article are:

  1. Risks of permanent spinal cord injury do not increase with past spinal cord concussions.
  2. There is a high risk of re-occurrence of SCC (56%) in football players.
  3. Players with preexisting stenosis have increased risk of SCI in contact sports.
  4. Patients with single level fusions may develop adjacent level spondylosis.

I don’t believe the author presents a strong case for their first aim: evaluate the criteria for return to contact sports after SCC. There are other criteria well defined in the literature to assist in the return to sport decision after a SCC. I have included supplemental information in the commentary section.

Commentary:

After a quick literature review I have found that caution and protection are the mainstays of concussion management. Patients with suspected SCC should be removed from physical activity and not allowed to return until evaluation by an experienced clinician demonstrates resolution of symptoms. Athletes must reach the following progressive benchmarks before being allowed to return to play.

1. Complete clearing of all symptoms at rest, with no pain medications.

2. No symptoms after provocative testing, i.e. cycling, running, or other exercise that elevates heart rate.

3. Full return of cognitive ability, memory, and concentration. (1-4)

A widely accepted graded return to play program (4) begins by avoiding physically and cognitively stressful activity until symptoms have resolved. At that point, the patient may begin light aerobic activity that maintains the heart rate below 70% max, i.e. walking, stationary cycling, etc. Structured aerobic activity has been shown to improve cerebral blood flow and reduce symptoms. (5-7) If low intensity aerobic testing does not exacerbate symptoms, the patient may slowly incorporate progressively more demanding activity, i.e. push-ups and running, eventually performing more complex, non-contact sport specific drills. After the patient is asymptomatic at both rest and after provocative exercise challenge, some form of neuropsychological testing should be performed to ensure the patient’s memory, concentration, and cognitive ability have returned to baseline. (1) Many teams are now performing a pre-season baseline assessment to allow better comparison with post-concussive test results. Athletes should obtain a “written clearance to participate” from a clearly qualified healthcare professional before returning to full activity. (8,9)

References:

1. P McCrory , M Makdissi, G Davis, A Collie Value of neuropsychological testing after head injuries in football Br J Sports Med 2005;39:i58-i63

2. McCrory P, Johnston K, Meeuwisse W, et al. Summary and agreement statement of the second International conference on Concussion in Sport, Prague 2004. Br J Sports Med 2005;39 (suppl 1) :i78–i86

3. Bernhardt, DT. Concussion Medscape Accessed 06/25/2016 http://emedicine.medscape.com/article/92095-overview

4. Canadian Academy of Sport Medicine Concussion Committee. Guidelines for assessment and management of sport-related concussion. Clinical Journal of Sport Medicine.2000;10(3):209–211

5. Baker JG, Freitas MS, Leddy JJ, Kozlowski KF, Willer BS. Return to Full Functioning after Graded Exercise Assessment and Progressive Exercise Treatment of Postconcussion Syndrome. Rehabilitation Research and Practice. 2012;2012:1–7.

6. Leddy JJ, Cox JL, Baker JG, Wack DS, Pendergast DR, Zivadinov R, et al. Exercise Treatment for Postconcussion Syndrome. Journal of Head Trauma Rehabilitation. 2013;28(4):241–9.

7. Leddy JJ, Kozlowski K, Donnelly JP, Pendergast DR, Epstein LH, Willer B. A

preliminary study of subsymptom threshold exercise training for refractory post- concussion syndrome. Clin J Sport Med. 2010 Jan 1;20(1):21

8. Consensus statement on concussion in sports-the third international conference on concussion in sport, held in Zürich, November 2008. Journal of Clinical Neuroscience 16 (2009) 755-763.

9. Consensus statement on concussion in sports-the forth international conference on concussion in sport, held in Zürich, November 2012. British Journal of Spots medicine 2013 47:250-258.