Cognitive and fine motor deficits in a pediatric sickle cell disease cohort of mixed ethnic origin

Abstract

Cerebrovascular disease is an important feature of pediatric sickle cell disease (SCD) and may lead to cognitive and motor impairment. Our cross-sectional study examined the incidence and severity of these impairments in a pediatric cohort without clinical cerebrovascular events from Berlin of mixed ethnic origin. Thirty-two SCD patients (mean age 11.14 years, range 7.0-17.25 years; males 14) were evaluated for full-scale intelligence (IQ) (German version WISC-III), fine motor function (digital writing tablet), and executive function (planning, attention, working memory, and visual-spatial abilities) with the Amsterdam Neuropsychological Tasks (ANT) program and the Tower of London (ToL). Data on clinical risk factors were retrieved from medical records. Full-scale IQ of patients was preserved, whereas performance IQ was significantly reduced (91.19 (SD 12.17) d = 0.7, p = 0.007). SCD patients scored significantly lower than healthy peers when tested for executive and fine motor functions, e.g., planning time in the ToL (6.73 s (SD 3.21) vs. 5.9 s in healthy peers (SD 2.33), d = 0.5, p = <0.001) and frequency on the writing tablet (mean z score -0.79, d = 0.7, p < 0.001). No clinical risk factors were significantly associated with incidence and severity of cognitive and motor deficits. Despite the preservation of full-scale IQ, our SCD cohort of mixed origin exhibited inferior executive abilities and reduced fine motor skills. Our study is limited by the small size of our cohort as well as the lack for control of sociodemographic and socioeconomic factors modulating higher functions but highlights the need for early screening, prevention, and specific interventions for these deficits.

Assessment of Executive Functions in Preschool Children With Sickle Cell Anemia

“…Contrary to current findings, previous studies have reported working memory deficits (Hijmans et al, 2011;Schatz & Roberts, 2007). There were no significant differences observed between groups on NIHTB Processing Speed, or on the processing speed components of the DDTP (DDTP motor phase/ DDTP completion time) which is also in contrast to findings for school-age children (Burkhardt et al, 2017;Smith & Shatz, 2016). In comparison to normative scores on NIHTB Processing Speed, both the patients and the controls showed poor processing speed, which may reflect the factors that they were matched on such as IQ or SES.…”

“…Children with early brain insult are sometimes described to “grow into” later emerging deficits when impairments are reported to emerge with brain development and as developmental expectations grow to incorporate higher-order skills such as planning, organizing, and problem-solving. The severity of EF dysfunction, the most common cognitive deficit in SCA, is related to increasing neurologic morbidity although poor EF remains in this patient population in the absence of neurologic morbidity (Berg, Edwards, & King, 2012; Berkelhammer et al, 2007; Burkhardt et al, 2017; Hensler et al, 2014; Hijmans et al, 2011; Hollocks et al, 2012; Kral & Brown, 2004; Nabors & Freymuth, 2002; Smith & Schatz, 2016).…”

Higher executive abilities following a blood transfusion in children and young adults with sickle cell disease

“…Cognitive deficits in individuals with SCD are well documented . Prior research, however, has been mixed as to whether medical treatments influence cognition in individuals with SCD . Additionally, most previous studies have assessed IQ rather than more specific cognitive domains.…”

“…In contrast, findings from a large‐scale trial showed that IQ was similar among children with silent cerebral infarct (SCI) who received chronic transfusion for 3 years and children with SCI who did not receive chronic transfusion; however, IQ testing was not timed to occur soon after a transfusion . Similarly, there were no differences in IQ and executive abilities among a very small sample of children with SCD with no history of stroke who received either chronic transfusion, HU, or neither treatment . IQ was also similar in children with no history of stroke who did and did not receive HU…”

“…As just illustrated, the focus of most previous studies has been on changes in IQ. In general, chronic transfusion has not been associated with improvement in IQ . However, IQ is a cognitive composite that essentially averages performance across a number of different cognitive domains.…”