Brain or strain? Symptoms alone do not distinguish physiologic concussion from cervical/vestibular injury

Clin J Sport Med. 2015 May;25(3):237-42. doi: 10.1097/JSM.0000000000000128.


Objective: To compare symptoms in patients with physiologic postconcussion disorder (PCD) versus cervicogenic/vestibular PCD. We hypothesized that most symptoms would not be equivalent. In particular, we hypothesized that cognitive symptoms would be more often associated with physiologic PCD.

Design: Retrospective review of symptom reports from patients who completed a 22-item symptom questionnaire.

Setting: University-based concussion clinic.

Patients: Convenience sample of 128 patients who had symptoms after head injury for more than 3 weeks and who had provocative treadmill exercise testing.

Independent variables: Subjects were classified as either physiologic PCD (abnormal treadmill performance and a normal cervical/vestibular physical examination) or cervicogenic/vestibular PCD (CGV, normal treadmill performance, and an abnormal cervical/vestibular physical examination).

Main outcome measures: Self-reported symptoms. Univariate and multivariate methods, including t tests, tests of equivalence, a logistic regression model, k-nearest neighbor analysis, multidimensional scaling, and principle components analysis were used to see whether symptoms could distinguish PCD from CGV.

Results: None of the statistical methods used to analyze self-reported symptoms was able to adequately distinguish patients with PCD from patients with CGV.

Conclusions: Symptoms after head injury, including cognitive symptoms, have traditionally been ascribed to brain injury, but they do not reliably discriminate between physiologic PCD and cervicogenic/vestibular PCD. Clinicians should consider specific testing of exercise tolerance and perform a physical examination of the cervical spine and the vestibular/ocular systems to determine the etiology of postconcussion symptoms.

Clinical relevance: Symptoms after head injury, including cognitive symptoms, do not discriminate between concussion and cervical/vestibular injury.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Athletic Injuries / diagnosis*
  • Brain Concussion / diagnosis*
  • Cervical Vertebrae / injuries*
  • Female
  • Humans
  • Male
  • Principal Component Analysis
  • Retrospective Studies
  • Vestibule, Labyrinth / injuries*
  • Young Adult