头痛、反应迟缓、朦胧感及记忆困难是典型症状。症状可能出现波动，但通常在 1 周到 1 个月后缓解。意识丧失并非阳性诊断的必要条件。
脑震荡损伤患者的 CT 扫描和 MRI 通常正常。
脑震荡（轻度创伤性脑损伤）是指由直接打击头部或头部受到冲力减速所致的闭合性颅脑损伤，可导致意识状态改变。 Centers for Disease Control and Prevention: HEADSUP external link opens in a new window
Instructor of Orthopaedic Surgery
Division of Sports Medicine
University of Pittsburgh Medical Centre for Sports Medicine Concussion Program
Department of Orthopaedic Surgery
University of Pittsburgh
LCH declares that he has no competing interests.
Assistant Clinical Professor
General Rehabilitation Unit
UPMC Physical Medicine and Rehabilitation
University of Pittsburgh Medical Center
MT declares that she has no competing interests.
Dr Luke C. Henry and Dr Maria Twichell would like to gratefully acknowledge Dr Jeffrey Bazarian and Dr Maryse Lassonde, previous contributors to this monograph. JB has been reimbursed by Roche, the manufacturer of an automated assay for serum S-100B, to attend a conference, and has been reimbursed by Banyan Biomarkers and Neuren Pharmaceuticals to help develop their research protocols. JB is also an author of a reference cited in this monograph. ML is an author of several references cited in this monograph.