Anthony Luke M.D., M.P.H.
Primary Care Sports Medicine Specialist
UCSF Sports Medicine Center
Loss of consciousness is no longer the main determining factor for concussion. Related symptoms such as irritability, labile emotions, sleep disturbances, cognitive slowing, headache, dizziness, ringing in the ears, nausea and blurred vision now are significant considerations in the diagnosis.
A concussion characteristically involves a rapid onset of symptoms, due to impaired neurological function that resolves spontaneously. Symptoms may appear immediately after the injury or may take several minutes to evolve.
Concussion is a clinical diagnosis, as neuroimaging is grossly normal. Athletes usually do not need a computed tomography (CT) scan acutely unless there is concern for intracranial bleeding. A careful history and neurologic exam should be done to detect mild cognitive deficits or abnormal neurologic signs.
The traditional grading systems of concussions by severity — grade 1, 2 and 3 as the worst — are discouraged due to poor correlation between grading symptoms and clinical importance. A new classification of "simple" versus "complex" concussion is recommended. A "simple" concussion resolves without complications over seven to 10 days. "Complex" concussions involve persistent symptoms lasting a few weeks, specific sequelae, prolonged loss of consciousness lasting more than one minute or prolonged cognitive impairment.(1)
Research regarding the long-term effects of repetitive minor head trauma has led to greater restrictions for returning to physical activity. The problem with early return to sports is that brain damage may be cumulative (additive) in nature.(2)
Young athletes with a diagnosis of concussion should be restricted from sports for at least one day. They should rest from tasks that require strenuous cognitive function. Activities involving physical exertion should be limited until all objective and significant subjective symptoms improve. The athlete should be checked daily for symptoms to determine when the concussive symptoms have cleared. Again, most concussions are "simple" and will resolve within seven days(3) while severe concussions may take a few weeks.
If the athlete is asymptomatic, participation in conditioning activities is reasonable as long as there is minimal risk of head injury. The number of previous concussions should be considered.(4) Contact activities should be prohibited until the athlete has recovered fully and the brain injury has had time to heal.
Computer-based evaluations can be used to assess cognitive function after injury and as an aid in return-to-play decisions.(5) Neuropsychological tests are helpful to measure cognitive abilities to make sure the asymptomatic athlete has returned to baseline functioning. It is helpful to have pre-season baseline scores for these tests. The use of these programs in the management of concussions is still being researched.
The Sport Concussion Assessment Test suggests screening procedures to assess a patient's mental status and cognitive function. The tool is available at multimedia.olympic.org/pdf/en_report_1006.pdf.
For more information, contact the Physician Referral Service at UCSF Medical Center:
|Phone||(888) 689-UCSF or (888) 689-8273|
(1) McCrory P, Johnston K, Meeuwisse W, Aubry M, Cantu R, Dvorak J, Graf-Baumann T, Kelly J, Lovell M, Schamasch P. Summary and agreement statement of the 2nd International Conference on Concussion in Sport, Prague 2004. Br J Sports Med. 2005; 39(4): 196-204.
(2)Collins MW, Lovell MR, Iverson GL, Cantu RC, Maroon JC, Field M. Cumulative effects of concussion in high school athletes. Neurosurgery. 2002; 51(5): 1175-9.
(3) Guskiewicz KM, McCrea M, Marshall SW, Cantu RC, Randolph C, Barr W, Onate JA, Kelly JP. Cumulative effects associated with recurrent concussion in collegiate football players: the NCAA Concussion Study. JAMA. 2003; 290(19): 2549-55.
(4)Guskiewicz KM, Marshall SW, Bailes J, McCrea M, Cantu RC, Randolph C, Jordan BD. Association between recurrent concussion and late-life cognitive impairment in retired professional football players. Neurosurgery. 2005; 57(4): 719-26.
(5) Iverson GL, Brooks BL, Collins MW, Lovell MR. Tracking neuropsychological recovery following concussion in sport. Brain Inj. 2006; 20(3): 245-52.