Arithmetic difficulties in children with mild traumatic brain injury at the subacute stage of recovery

Abstract

EOGElectrooculography ERP Event-related potential LPC Late positivity component mTBI Mild traumatic brain injury AIM Arithmetic difficulties have been reported in children with mild traumatic brain injury (mTBI), but the electrophysiological abnormalities underlying these impairments remain unknown. We therefore used event-related potentials (ERPs) to investigate brain functioning during arithmetic in children in the subacute phase after mTBI.METHOD The participants comprised 16 children with mTBI at the subacute phase of recovery (10 males, mean age 10y 8mo; six females, mean age 10y 8mo) and 16 well-matched comparison children (11 males, mean age 10y 11mo; five females, mean age 10y 6mo). All children were asked to solve single-digit addition problems of small (sum ≤10) and large problem size (sum >10) and ERPs were simultaneously recorded. RESULTSChildren with mTBI performed significantly less accurately (mean 81%) than comparison children (mean 91%) on the large (p=0.026) but not on the small problems (p=0.171). We observed no group differences in the early ERP components P1, N1, P2, and N2 (all p values ≥0.241), yet significant group differences (p=0.019) emerged for the late positivity component (LPC), which showed smaller mean amplitudes (mean 8.35lV) in mTBI patients than comparison children (mean 12.95lV).INTERPRETATION Immediately after the injury, arithmetic difficulties in children with mTBI are particularly pronounced on more complex arithmetical problems that are less automated. This is reflected in the ERP pattern, with decreased LPC but normal N2 and early ERP components.Paediatric mild traumatic brain injury (mTBI) is known to produce cognitive problems (such as deficits in working memory) as well as academic difficulties (predominantly problems regarding arithmetic) at the subacute stage of the injury. 1-3 These cognitive and arithmetic difficulties are subtle, even though they may influence daily activities or performance at school. 4 Recently, neuroimaging, such as functional magnetic resonance imaging, and electrophysiological techniques, such as event-related potentials (ERPs) have started to unravel the underlying neurophysiological bases of cognitive dysfunctions associated with mTBI. ERPs are an ideal method for monitoring the flow of information in the brain during the performance of a cognitive task, even in the case of subtle cognitive deficits that might not always be detected by means of standard clinical tests, such as arithmetic difficulties in mTBI. This approach has also an excellent temporal resolution, which gives researchers the ability to follow cognitive processes with milliseconds precision. To the best of our knowledge, no ERP study in arithmetic has been conducted in mTBI patients. Moreover, there have been no group studies in children with mTBI investigating the subacute stage of injury. We therefore used ERPs during an arithmetic task to refine our understanding of arithmetical difficulties in pediatric mTBI at the subacute stage of recovery (i.e. 4wks after injury).Va...

Advanced biomarkers of pediatric mild traumatic brain injury: Progress and perils

“…In a cross-sectional study utilizing resting-state EEG, the British Columbia group (Balkan et al, 2015; Virji-Babul et al, 2014) reported increased beta, reduced theta, and reduced delta power across several frontal sources for SRC patients relative to uninjured control athletes, as well as abnormal connectivity metrics. In a study with overlapping samples, the Belgium group (van Beek et al, 2015a) utilized EEG to demonstrate that pmTBI patients exhibited lower amplitude in a late positivity component (posited to reflect attentional failure) during cognitive tasks, but were similar across more basic early sensory components. Finally, Broglio and colleagues (Broglio et al, 2016) prospectively (symptomatic, self-report asymptomatic, return to play, and one-month post asymptomatic) examined an SRC sample and matched uninjured athlete controls for changes in Brain Network Activation, an EEG measure of interconnectedness, during auditory oddball and go/no go tasks.…”

N2b Reflects the Cognitive Changes in Executive Functioning After Concussion: A Scoping Review

“…Two hundred and fifty-eight articles were identified from the database searches and reviewed bibliographies, of which 66 were included in the final review (see Supplementary Table 1; Figure 1). Due to the recency of N2 subcomponent classification, the vast majority of included studies referred to the general class of N2 components; only six studied the N2b subcomponent (i.e., Czigler et al, 1996;Lange et al, 1998;Smid et al, 1999;Senkowski and Herrmann, 2002;Czigler and Balázs, 2005;Van Beek et al, 2015). Eight of the included N2 papers specifically investigated concussion (i.e., Broglio et al, 2009;Gosselin et al, 2012;Moore et al, 2014Moore et al, , 2015Moore et al, , 2016Ledwidge and Molfese, 2016;Hudac et al, 2018;Olson et al, 2018).…”

“…The N2 group includes several sub-components such as the N2a (more commonly known as the mismatch negativity), which represents pre-attentive stimulus processing in a manner that has been conceptualized in terms of predictive coding (Friston, 2005;Garrido et al, 2009); the N2c, representing stimulus discrimination and response priming; the N2b, discussed in detail below; the N2p, implicated in target detection and global spatial processing; and the N2pc, implicated in visual search (Näätänen and Picton, 1986;Patel and Azzam, 2005;Folstein and Van Petten, 2008;Van Beek et al, 2015). However, due to the lack of consistency in subcomponent classification, components in this group are often referred to as the general "N2" or by their specific latency, such as, "N270" (Connolly et al, 1995;Helenius et al, 1999;Cui et al, 2000;Kong et al, 2000;Wang et al, 2003Wang et al, , 2004Bartholow et al, 2005;Patel and Azzam, 2005;Azizian et al, 2006;Folstein and Van Petten, 2008;Luck, 2014).…”

“…Standard neuropsychological tests as well as computerized administration of cognitive tests including the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) are typically used to measure cognitive and emotional control among people with concussion, yet lack the sensitivity to measure the more subtle manifestations of cognition including executive functioning deficits after symptom resolution (Broglio et al, 2009;Ledwidge and Molfese, 2016;Hudac et al, 2018;Olson et al, 2018). Executive functioning skills, including time management, task switching, sustained attention and working memory, are vital for career and interpersonal success yet can be challenging to accurately measure (Elliott, 2003;Van Beek et al, 2015;Downes et al, 2017). Therefore, more accurate and sensitive measures of chronic cognitive deficits in the post-acute stage of recovery are needed, and ERPs are a promising approach to achieve this objective (Broglio et al, 2009;Ledwidge and Molfese, 2016;Olson et al, 2018).…”

Electrophysiological testing in concussion: A guide to clinical applications

“…80 Furthermore, concussed subjects who were, on average, over three years post-injury demonstrated decrements in N2 and P3b amplitudes relative to individuals without a history of concussion, 83 in response to a three-stimulus oddball task, although other research has shown no difference. 84 Nevertheless, the P3 component has been repeatedly shown to have chronic amplitude suppression among multi-concussion athletes. [85][86][87][88][89][90][91] However, results have been mixed with previous study of an auditory oddball and Go/No-go tasks not differentiating concussed athletes from controls, [92][93][94] whilst other similar research has shown differences.…”