Baseline testing is increasingly being used and recommended in the USA and only just beginning to emerge here in Australia (neuropsych testing only). Baseline testing typically involves neurocognitive testing that allows you to document the healthy brain function of an uninjured test taker. If they suffer a head injury, post-injury testing is believed to identify the cognitive deficits incurred and help you make concussion treatment decisions. At Neuroperformance, we still see value in including neurocognitive testing and use the COGNIFIT battery of neuropsych tests.
The reliability of traditional cognitive assessment tools is debatable, yet it is critical to assess concussion and mild traumatic brain injury (mTBI) with high accuracy to avoid post-concussion syndrome.
Numerous other diagnostic tools exist, but few are cost-effective. Many investigative options have been proposed to diagnose and characterize concussion. CT is the most commonly used imaging modality—mainly because it is quick, widely available and relatively inexpensive. While CT can rule out significant trauma, it does little to help the provider in a concussion workup. MRI and neuropsychologic testing get us a bit closer, but are much more time-consuming and expensive, especially the latter. Newer work positron emission tomography (PET), functional MRIs (fMRIs), and certain biomarkers (e.g., GFAP, UCH-L1) is intriguing but not ready for prime time.
Rethinking electroencephalography (EEG) in concussion: The power of QEEG.
Perhaps surprisingly, EEG was used as early as the 1940s to establish a qualitative link between TBI and abnormal brain function. Despite decades of research, standard EEG never emerged as a first line diagnostic tool for concussion. This has perhaps changed with the advent of more sophisticated technologies such as QEEG (quantitative EEG) and advanced EEG diagnostic algorithms. In broad-ranging 2017 literature review 460 articles from between 1996 and 2016, Authors Ianof and Anghinah concluded that conventional EEG is only useful in the evaluation of post-concussion epilepsy, but “not useful as a routine screening measure among individuals with mTBI or postconcussive symptoms.” Their assessment of QEEG, however, was just the opposite. In concussed individuals, QEEG showed immediate reduction in mean alpha frequency, with increased theta, increased delta, or increased theta:alpha ratio.2 While the authors highlighted the fact that no clear EEG of QEEG features are unique to mTBI, their research revealed patterns of QEEG abnormality that correlated with acute, subacute and chronic concussion. From these results, the authors conclude QEEG “appears promising as a diagnostic assessment for mTBI and post-concussive symptoms.”
In a systematic literature review of studies examining resting state EEG (rsEEG) following concussion, Conley et al. found that concussed athletes rather consistently exhibit abnormal theta oscillations.3 The authors also noted that compared to pre-injury baseline or controls, concussed players had lower theta power, increased theta coherence, or increased frontotemporal theta power.3 Importantly, abnormalities in theta oscillations are associated with difficulties in attention goal directed cognition, decision-making, athletic performance, memory and sleep. They are also associated with anxiety and suicidal ideation. Larger studies will be required to determine if there are consistent pathognomonic features on rsEEG to determine the severity of concussion and predict outcome and risk of recurrence.
QEEG as a tool for pre-season screening, post-concussion assessment, and long-term follow up
The Committee on Sports-Related Concussions in Youth (USA) writes in Sports-Related Concussions in Youth: Improving the Science, Changing the Culture, that QEEG “can detect differences in performance and neural responses in concussed versus non-concussed student athletes in high school and college even when behavior measures fail to do so… Such results suggest that QEEG techniques could provide a more effective means to identify athletes with impairments following concussion and to predict when they might more safely return to play.”4
While it remains difficult to elucidate any EEG or even QEEG changes that reliably occur in individuals with concussion (post injury) and that are absent in healthy controls, the power to detect meaningful changes in my view, lie in BASELINE pre-and post-concussion comparisons. Since QEEG acquisition is now significantly more affordable, there is a strong argument for QEEG screening for athletes as part of their preseason health physicals. This data would be an invaluable comparator for concussion assessment to help identify theta wave changes and other indictors consistent with acute TBI and concussion.
More studies are always needed. However, in my view and in considering the other areas within which Qeeg is being used, there is a credible and established basis both in the literature and in practice, particularly when the risks are so high and a lack of anything of value currently available, for this tool to be used at this point as a baseline and post-concussion comparison. This provides a very powerful, and uniquely individualized tool to identify brain changes; target and implement recovery treatment that is personalized, and monitor the brains recovery. This may be helpful in being more informed around return to sport readiness and thereby possibly reduce the risk of long-term impacts such as CTE.
Give Neuroperformance a call for your Pre-Season, Baseline cognitive and Qeeg testing.