Cognitive Dysfunction Common in Patients with Sickle Cell Anemia

A new systematic review found cognitive dysfunction a defining characteristic of individuals with sickle cell anemia (SCA) across all age groups, suggesting a notable impact on quality of life and functional independence.¹

Across the review of 18 studies, with nearly 2500 participants with SCA, the prevalence of cognitive dysfunction ranged from 11.5% to 70% in adults with SCA, and ranged from 10.2% to 68.2% in children with SCA.

“The findings underscore a crucial implication: without effective strategies to slow or ideally halt cognitive decline, any medical interventions aimed at addressing various associated symptoms and complications of SCA are likely to be rendered ineffective,” wrote the investigative team, led by Nazim F. Hamed, general pediatrics, Security Force Hospital.

The potential link between SCA and cognitive dysfunction, a representation of difficulties with thinking, learning, and memory, has been explored in recent years.² This research could improve the comprehension of SCA-related complications and lead to new treatments to improve these individuals' cognitive function.

Multiple pathways by which SCA may result in cognitive impairment include the aberrant morphology of the red blood cells restricting blood flow to the brain.³ There are no specific treatments for cognitive dysfunction in SCA, but cognitive rehabilitation, education support, and interventions to address SCA complications could impact cognitive function.

In this study, Hamed and colleagues investigated the existing evidence to unveil the association between SCA and cognitive dysfunction, to add to the development of targeted interventions and support strategies to improve the quality of life of individuals with SCA.¹ The team searched electronic databases, including PubMed, MEDLINE, Science Direct, and Scopus.

The search identified 2,216 papers after 1,299 duplicates were eliminated. After 108 papers were screened for full-text evaluation, 62 were rejected due to incorrect study results, 22 due to incorrect population type, 2 for editor’s letters, and 4 for abstracts. Ultimately, 18 studies met the qualification criteria, with a total of 2,457 individuals (46.8% male).

Among the 18 studies, 8 focused on adults with SCA, with the prevalence of cognitive impairment ranging from 11.5% to 70%. Cognitive dysfunction in this patient population was significantly associated with poorer educational status, reduced family income, decreasing kidney function, older age, stroke history, and vasculopathy.

The other 10 studies included the pediatric population with SCA, for a cognitive dysfunction prevalence of 10.2% to 68.2%. Cognitive function decline was significantly associated with children over the age of 4 years, abnormal transcranial Doppler and previous stroke, school absence, age ≥13 years, and increased body mass index (BMI).

Based on these data, Hamed and colleagues called for further research to include more diverse populations, to allow for a clearer understanding of socioeconomic, geographic, and genetic factors influencing cognitive outcomes in SCA. A significant association identified between SCA and cognitive dysfunction could lead to targeted cognitive interventions enhancing the quality of life for those with SCA.

“The implications of this research extend beyond the clinical realm; findings may inform health policies geared toward improving care quality for individuals with SCA, ensuring that cognitive health resources and support services are accessible,” they wrote.

References

1. _{Alpakra M, Hamed NF, Almakki ZE, Al Bakrah E. The Association Between Sickle Cell Anemia and Cognitive Dysfunction: A Systematic Review. Cureus. 2024;16(9):e69104. Published 2024 Sep 10. doi:10.7759/cureus.69104}
2. _{Ojinnaka U, Ahmed Z, Kannan A, et al. A Traditional Review of Sickle Cell Disease and the Associated Onset of Dementia: Hematological and Neurocognitive Crossroads. Cureus. 2021;13(10):e18906. Published 2021 Oct 19. doi:10.7759/cureus.18906}
3. _{Iampietro M, Giovannetti T, Tarazi R. Hypoxia and inflammation in children with sickle cell disease: implications for hippocampal functioning and episodic memory. Neuropsychol Rev. 2014;24(2):252-265. doi:10.1007/s11065-014-9259-4}