Processing speed in children treated for brain tumors: effects of radiation therapy and age

Abstract

The current study examined processing speed in children two years post-treatment for brain tumors (BT) with radiation therapy (RT) compared to those treated with without RT. Participants included 59 children (4-17 years) with BT assessed as part of the Brain Radiation Investigative Study Consortium (BRISC). Processing speed was assessed at two time points: Time1 (3-9 months post-surgery) for 26 children who received whole brain or focal RT (RT group) and 33 treated without RT (no-RT group), and again two years later (Time2) for 42 participants (17 RT, 25 no-RT). Linear mixed effects (LME) regression analyses examined differences in cognitive and motor speed between groups and across visits, with age at Time1 (age1) treated as a moderating variable, and sex and primary tumor size as covariates. No effects for treatment group or visit were found for motor speed (Pegboard) or mean reaction time (Attention Network Task). On the Wechsler Processing Speed Index (PSI), the no-RT group performed better than the RT group, with a group-by-age interaction such that across visits, the difference between the no-RT and RT groups was larger among children who were older at initial treatment (≥10 years) than among those who were younger (<10 years). Cumulative brain injury earlier in life (tumor, surgery, plus RT) may result in greater impact on more complex tasks of cognitive efficiency. Children receiving RT showed reduced processing speed over time, with a larger group difference among those who were over 10 years at treatment.

The Effects of Radiation and Sex Differences on Adaptive Functioning in Adult Survivors of Pediatric Posterior Fossa Brain Tumors

“…This model also implicates processing speed deficits as contributing to both higher-order deficits but also other core cognitive processes such as working memory and attention that ultimately feed into higher-order processes. Other studies have also found processing speed to be most sensitive to treatment, age at treatment administration, and location of tumor, suggesting that the origin of processing speed deficits is multifactorial (Jacobson et al, 2018). Of note, when categorized as impaired (z ≤ −1.5) versus within normal limits, 9 of our 21 male participants (3 of the 9 who did not undergo RT and 6 of the 12 who underwent RT) had performed within the impaired range on the OSDMT, indicating that there are likely various tumor and treatment factors that are involved in performance.…”

Processing Speed and Time since Diagnosis Predict Adaptive Functioning Measured with WeeFIM in Pediatric Brain Tumor Survivors

“…Regarding the cognitive variables, we decided to examine the explanatory effect of PS only, as preliminary analysis showed strong correlations (all r ≥ 0.50, p < 0.001) between all the WISC-IV indexes and PS, which may have led to multicollinearity problems. Our decision was also based on the relevant literature about the key role of PS in BT survivors and its deterioration, even when cognitive functioning is preserved [ 16 , 17 , 53 , 54 ].…”