Regardless of genotype, patients with sickle cell disease (SCD) demonstrated worse cognitive performance across multiple domains compared with healthy controls, according to findings published in the American Journal of Hematology.

Researchers compared cognitive testing results from 86 patients with SCD representative of all genotypes with 66 healthy controls. Patients with SCD were recruited from the University of Pittsburgh Medical Center Adult Sickle Cell Program outpatient clinic between 2016 and 2019.

The complete battery of neurocognitive tests included the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), the Digit Symbol Substitution Test (DSST), the Hopkins Verbal Learning Test – Revised (HVLT-R), and the Delis-Kaplan Executive Function System (D-KEFS).

Compared with controls, patients with SCD scored lower on average across all neurocognitive tests. More than 50% of patients with SCD scored below normal ranges for total recall (HVLT-R), immediate memory (RBANS), and language (P =.014) (RBANS). More than 60% scored below normal ranges on the RBANS for attention (P <.001), visuoconstruction, and total index scores (P <.001). Patients with SCD also demonstrated significantly lower scores on the DSST and D-KEFS compared with controls (both P <.001).

Patients with SCD who had a stroke history demonstrated significantly worse scores on the DSST (P =.015), RBANS total index (P =.02), and Executive Function Domain (P =.012). However, patients with SCD still exhibited cognitive impairments in the absence of stroke.

Read more about SCD clinical features

The researchers noted that few patients in this cohort received chronic transfusions, suggesting that these transfusions may potentially protect against cognitive impairment. They recommended that larger cohort studies evaluate the impact of chronic transfusions on cognitive function in the future.

“These findings demonstrate the pervasiveness of impairments across heterogeneous areas of cognitive function, independent of [SCD] genotype,” the authors said. “The findings from this study can improve clinical care for SCD patients and serve as a basis for measuring the impact of treatments such as chronic transfusions on various domains of cognitive performance.”


Portela GT, Butters MA, Brooks MM, Candra L, Rosano C, Novelli EM. Comprehensive assessment of cognitive function in adults with moderate and severe sickle cell disease. Am J Hematol. Published online June 24, 2022. doi:10.1002/ajh.26643