title: Pediatric sports-related concussion produces cerebral blood flow alterations.
abstract: OBJECTIVE
  The pathophysiology of sports-related concussion (SRC) is incompletely understood. Human adult and experimental animal investigations have revealed structural axonal injuries, decreases in the neuronal metabolite N-acetyl aspartate, and reduced cerebral blood flow (CBF) after SRC and minor traumatic brain injury. The authors of this investigation explore these possibilities after pediatric SRC.
  
  
  METHODS
  Twelve children, ages 11 to 15 years, who experienced SRC were evaluated by ImPACT neurocognitive testing, T1 and susceptibility weighted MRI, diffusion tensor imaging, proton magnetic resonance spectroscopy, and phase contrast angiography at <72 hours, 14 days, and 30 days or greater after concussion. A similar number of age- and gender-matched controls were evaluated at a single time point.
  
  
  RESULTS
  ImPACT results confirmed statistically significant differences in initial total symptom score and reaction time between the SRC and control groups, resolving by 14 days for total symptom score and 30 days for reaction time. No evidence of structural injury was found on qualitative review of MRI. No decreases in neuronal metabolite N-acetyl aspartate or elevation of lactic acid were detected by proton magnetic resonance spectroscopy. Statistically significant alterations in CBF were documented in the SRC group, with reduction in CBF predominating (38 vs 48 mL/100 g per minute; P = .027). Improvement toward control values occurred in only 27% of the participants at 14 days and 64% at >30 days after SRC.
  
  
  CONCLUSIONS
  Pediatric SRC is primarily a physiologic injury, affecting CBF significantly without evidence of measurable structural, metabolic neuronal or axonal injury. Further study of CBF mechanisms is needed to explain patterns of recovery.
authors: Division of Neurosurgery, Department of Surgery, Cincinnati Children's Hospital Medical Center, MLC 2016, 3333 Burnet Ave, Cincinnati, OH 45229-3039, USA. todd.maugans@cchmc.org
authors: Todd A
authors: TA
authors: Maugans
authors: Chad
authors: C
authors: Farley
authors: Mekibib
authors: M
authors: Altaye
authors: James
authors: J
authors: Leach
authors: Kim M
authors: KM
authors: Cecil
mesh_terms: D000293:Adolescent; D001265:Athletic Injuries / Q000175:diagnosis / Q000503:physiopathology*; D001924:Brain Concussion / Q000175:diagnosis / Q000503:physiopathology*; D002560:Cerebrovascular Circulation; D002648:Child; D056324:Diffusion Tensor Imaging; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D009460:Neurologic Examination