title: Brain or strain? Symptoms alone do not distinguish physiologic concussion from cervical/vestibular injury.
abstract: 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.
  
  
  METHODS
  Retrospective review of symptom reports from patients who completed a 22-item symptom questionnaire.
  
  
  METHODS
  University-based concussion clinic.
  
  
  METHODS
  Convenience sample of 128 patients who had symptoms after head injury for more than 3 weeks and who had provocative treadmill exercise testing.
  
  
  METHODS
  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).
  
  
  METHODS
  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.
  
  
  CONCLUSIONS
  Symptoms after head injury, including cognitive symptoms, do not discriminate between concussion and cervical/vestibular injury.
authors: *Department of Orthopaedics, State University of New York at Buffalo, Buffalo, New York; †University Sports Medicine, Department of Orthopaedics, State University of New York at Buffalo, Buffalo, New York; Departments of ‡Nuclear Medicine and Orthopaedics; and §Family Medicine, State University of New York at Buffalo, Buffalo, New York; ¶SUNY Buffalo School of Medicine and Biomedical Sciences, Buffalo, New York; ‖Department of Biostatistics, State University of New York at Buffalo, Buffalo, New York; and **Department of Psychiatry, State University of New York at Buffalo, Buffalo, New York.
authors: John J
authors: JJ
authors: Leddy
authors: John G
authors: JG
authors: Baker
authors: Asim
authors: A
authors: Merchant
authors: John
authors: J
authors: Picano
authors: Daniel
authors: D
authors: Gaile
authors: Jason
authors: J
authors: Matuszak
authors: Barry
authors: B
authors: Willer
mesh_terms: D000293:Adolescent; D000328:Adult; D001265:Athletic Injuries / Q000175:diagnosis*; D001924:Brain Concussion / Q000175:diagnosis*; D002574:Cervical Vertebrae / Q000293:injuries*; D005260:Female; D006801:Humans; D008297:Male; D025341:Principal Component Analysis; D012189:Retrospective Studies; D014722:Vestibule, Labyrinth / Q000293:injuries*; D055815:Young Adult