Dr Torres is Director of the Pediatric Traumatic Brain Injury Program at Boston Medical Center and Assistant Professor of Pediatrics and Neurology at Boston University School of Medicine. He is also a member of the Department of Public Health, Sports Concussion Expert, Clinical Advisory Committee. Dr Shaikh is from SMIMER Medical College and Research Assistant at the Pediatric Trauma Brain Injury Program, Boston Medical Center.
The term concussion came to fame in the past decade, as is evidenced by the increase in the number of concussion-related publications in recent years. With fame came a lot of confusion and controversy related to its definition, diagnostic criteria, management and return to a normal lifestyle. In addition, there is a significant knowledge gap in concussion care and management amongst health care providers.1 Although there is no universally accepted definition for a concussion, the American Academy of Neurology describes a concussion as a trauma-induced alteration in mental status that may or may not involve loss of consciousness.2 Explained differently, a concussion is an abnormality in the biochemical processes leading to functional impairment without any evidence of structural findings on standard neuroimaging.
To add to the confusion, concussion has been interchangeably used with the term mild traumatic brain injury; this equivalence is up for debate as some believe that the traumatic brain injury may have a more severe course. In this article, we provide a brief discussion on the impact of concussion on the pediatric population, the current trends in concussion care, recent advances, future implications, and the challenges faced in the management of concussion.
Concussion in pediatrics
A concussion is a complex condition that has been poorly studied in the pediatric population. The effect and outcome of concussion are far worse in the developing brains of children as compared to that of adults. Studies have shown that concussion in this age group significantly impacts school and sports-related performance, and it often leads to significant academic, social, and financial losses. Concussion may even cause permanent damage and worsening of existing neuropsychological symptoms. Most concerning, repeated head injuries, particularly recurrent and prolonged subconcussive injuries, may lead to a much more severe condition like the chronic traumatic encephalopathy.
Issues in diagnosis
The diagnosis of concussion is mostly clinical and is based on the presence of a constellation of symptoms developed as a consequence of trauma to the head (directly or indirectly). It is suspected with the presence of any of the following symptoms: headache, loss of consciousness, confusion, dizziness, and nausea and vomiting.1 There are many assessment tools that aid in the diagnosis of concussion, including:
- The Post-Concussion Symptom Scale (PCSS)
- Sport Concussion Assessment Tool 5 (SCAT 5)
- Standard Assessment of Concussion (SAC)
- Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT)
- Concussion Resolution Index (CRI)
- King-Devick (KD) test
However, the subjective nature of these assessment tools limits their utility.3 Currently, there is no imaging or laboratory test to diagnosis concussion. Traditional neuroimaging like CT scan and MRI that are used to rule out more serious traumatic brain injury are of little value in diagnosing concussion, as they only identify structural abnormalities. Also, the possibilities of radiation with CT scan and need for sedation in MRI restricts the use of these modalities to certain conditions. While a protocol has been established for the use of the CT scan in traumatic brain injury (ie, the PECARN rule), there is no protocol for the use of MRI. As such, clinician discretion determines MRI use in the pediatric population.
Since concussion is a functional disorder, attempts have been made to identify vascular and metabolic abnormalities through newer imaging modalities, laboratory tests (eg, fluid biomarkers), genetic testing, and electrophysiology. Recent advances in neuroimaging modalities like diffusion tensor imaging (DTI), magnetic resonance spectroscopy (MRS), functional MRI (fMRI), susceptibility-weighted imaging (SWI), and the like have shown potential use in the diagnosis of concussion.
DTI is a noninvasive method that allows estimation of the integrity of white matter tracts and has validated use in detecting axonal damage.4 Functional MRI shows abnormality in the blood oxygenation through BOLD (blood oxygenation dependent) signals in a concussed brain.5 Changes in N-acetylaspartate (NAA)/creatine and NAA/choline ratios can be detected on MRS, but the utility of these techniques only have been studied in a research environment and their routine clinical use has not been established yet. Transcranial-Doppler ultrasound (TCD) is an exciting modality that measures the cerebrovascular reactivity index, mean velocity of blood flow, and pulsatility index. It has already been shown that the cerebrovascular reactivity decreases post-concussion and that concussion can be effectively diagnosed through TCD. TCD provides a noninvasive and low-cost option, but further research is required before routine use.6
1. Mann A, Tator CH, Carson JD. Concussion diagnosis and management: Knowledge and attitudes of family medicine residents. Can Fam Physician. 2017;63:460-466.
2. Kirkwood MW, Yeates KO, Wilson PE. Pediatric sport-related concussion: A review of the clinical management of an oft-neglected population. Pediatrics. 2006;117:1359-1371.
3. Dessy AM, Yuk FJ, Maniya AY, et al. Review of Assessment Scales for Diagnosing and Monitoring Sports-related Concussion. Cureus. 2017; 9(12):e1922.
4. Bartnik-Olson BL, Holshouser B, Wang H, et al. Impaired neurovascular unit function contributes to persistent symptoms after concussion: a pilot study. J Neurotrauma. (2014)31:1497–506.
5. Di Battista, Churchill N, Schweizer TA et al. Blood biomarkers are associated with brain function and blood flow following sport concussion. J Neuroimmunol. 319:1–8.
6. Thibeault CM, Thorpe S, O’Brien MJ et al. A cross-sectional study on cerebral hemodynamics after mild traumatic brain injury in a pediatric population. Front Neurol. 2018; 9:200.
7. Papa L. Potential blood-based biomarkers for concussion. Sports Med Arthrosc Rev. 2016; 24(3):108-115.
8. Zetterberg H, Smith DH, Blennow K. Biomarkers of mild traumatic brain injury in cerebrospinal fluid and blood. Nat Rev Neurol. 2013; 9(4):201-210.
9. Jeter CB1, Hergenroeder GW, Hylin MJ, et al. Biomarkers for the diagnosis and prognosis of mild traumatic brain injury/concussion. J Neurotrauma. 2013; 30(8):657-70.