White and grey matter relations to simple, choice, and cognitive reaction time in spina bifida

Abstract

Elevated reaction time (RT) is common in brain disorders. We studied three forms of RT in a neurodevelopmental disorder, spina bifida myelomeningocele (SBM), characterized by regional alterations of both white and grey matter, and typically developing individuals aged 8 to 48 years, in order to establish the nature of the lifespan-relations of RT and brain variables. Cognitive accuracy and RT speed and variability were all impaired in SBM relative to the typically developing group, but the most important effects of SBM on RT are seen on tasks that require a cognitive decision rule. Individuals with SBM are impaired not only in speeded performance, but also in the consistency of their performance on tasks that extend over time, which may contribute to poor performance on a range of cognitive tasks. The group with SBM showed smaller corrected corpus callosum proportions, larger corrected cerebellar white matter proportions, and larger corrected proportions for grey matter in the Central Executive and Salience networks. There were clear negative relations between RT measures and corpus callosum, Central Executive, and Default Mode networks in the group with SBM; relations were not observed in typically developing age peers. Statistical mediation analyses indicated that corpus callosum and Central Executive Network were important mediators. While RT is known to rely heavily on white matter under conditions of typical development and in individuals with adult-onset brain injury, we add the new information that additional involvement of grey matter may be important for a key neuropsychological function in a common neurodevelopmental disorder.

Cognitive control and associated neural correlates in adults with spina bifida myelomeningocele.

“…As expected from our previous findings, the adults with SBM exhibited parallel deterioration of cognitive control abilities to that in normal aging (Dennis et al, 2015; Treble-Barna et al, 2015). With the exception of performance accuracy during the WMST, none of the group by age interactions significantly related to cognitive performance.…”

“…This has lead to the formulation of a modal profile of cognitive processing in SBM that includes relatively spared associative processing abilities, such as the activation and categorization of information related to stimuli that is based on formed associations, and relatively disrupted assembled processing or integration of information, particularly to exogenous stimuli. Although the conceptualization of this profile is predominantly based on studies of younger individuals and youth, the two known studies of adults with SBM supported assembled processing deficits of impaired prospective and verbal episodic memory and response (processing) speed (Dennis et al, 2015; Treble-Barna et al, 2015). In the current study, difficulty responding to learned associations of visually presented stimuli supported deficient capacity for maintaining information of exogenous stimuli in the adults with SBM.…”

Editorial. The challenges of implementing evidence-based practices in pediatric neurosurgery

“…8 There are few studies of the default mode network and pertinent related networks in adolescents and young adults born very preterm or with myelomeningoceles. 3,4,10 But current results demonstrate that these patients have abnormal networks. 3,4,10 Pediatric neurosurgeons need to advocate for more research about shunt-dependent hydrocephalus to understand the relevant pathophysiology and to develop interventions specific for patients with this condition.…”

“…3,4,10 But current results demonstrate that these patients have abnormal networks. 3,4,10 Pediatric neurosurgeons need to advocate for more research about shunt-dependent hydrocephalus to understand the relevant pathophysiology and to develop interventions specific for patients with this condition. Currently, very few evidencebased recommendations are available to treat chronic headaches in patients with congenital brain abnormalities, including those with shunted hydrocephalus.…”

Role of Neurocognitive Factors in Academic Fluency for Children and Adults With Spina Bifida Myelomeningocele

“…Processing speed tasks are often used in studies of academic skills (Shanahan et al, 2006); there is evidence that RT and processing speed measures are significantly correlated with one another, and that more complex measures show stronger relations with academic achievement (Buckhalt, 1991;Catts, Gillispie, Leonard, Kail, & Miller, 2002). A recent crosssectional study of RT (Dennis et al, 2016) used a wide age range (ages 8 to 40) and found that, despite slowed RTs relative to TD controls, individuals with SBM exhibited similar (complex quadratic) relations between RT and age, showing rapid decreases through childhood/adolescence, with slower rises through adulthood. What has not been studied is how other neurocognitive domains predict academic fluency outcomes when RT for non-academic stimuli is included in the models.…”