Neurocognitive Changes in Sickle Cell Disease: A Comprehensive Review

Abstract

Background: Sickle cell disease (SCD) is a type of hemoglobinopathy characterized by abnormal hemoglobin molecules, which includes numerous acute and chronic complications. Ischemic stroke, silent cerebral infarction, headache, and neurocognitive impairment are the most common neurological complications associated with SCD. Summary: Acute anemia because of SCD can cause cognitive impairments because of cerebral hypoxia. Cognitive abnormalities in SCD manifest in various aspects such as working memory, verbal learning, executive functions, and attention. These neurocognitive impairments have been associated with poor functional results, such as transitioning from juvenile to adult care, adherence to medications, and unemployment. Key message: In this review, we focus on neurocognitive aspects of SCD patients based on different imaging techniques, psychological batteries, associated neuromarkers, and interventions for managing of cognitive deficiencies..

Early Strokes Are Associated with More Global Cognitive Deficits in Adults with Sickle Cell Disease

“…In adulthood, the interest in cognition seems to decrease with sparse published studies as we can notice in the meta-analysis of Prussien et al on cognitive functioning in SCD patients (only 7 studies on SCD adult patients against 103 studies on children) [ 10 ]. This lack was also observed in Sahu’s review, where the majority of studies are on children or young adults [ 11 ]. However, this issue is also important, as the SCD population is getting older, and cognitive disorders make medical follow-up and social support more difficult.…”

“…In a recent comprehensive review, Sahu et al reported mainly dysexecutive disorders with learning difficulties, working memory disorders and attentional disorders in adults and children, with dramatic consequences both in their daily and professional lives, but also in terms of therapeutic follow-up. Cognitive disorders are more important in patients with cerebro-vascular disorders like stroke and/or SCI or vasculopathy [ 11 , 12 ]. However, cognitive disorders were depicted in adult patients with SCD, even in the absence of overt neurological events, in a neuroimaging study [ 13 ].…”

Overview of the Association Between the Pathophysiology, Types, and Management of Sickle Cell Disease and Stroke

“…Silent cerebral infarcts detected on MRI are common in SCD patients and are associated with cognitive deficits even without overt stroke symptoms [82,88]. Cognitive impairments after an overt stroke include issues with language, processing speed, memory, and executive functions [87,89]. However, long-term studies on cognitive outcomes are also lacking.…”

“…A cooperative study of SCD found that patients with a TIA had a 10-fold increased risk of subsequent IS compared to those without a TIA history [57,82]. Chronic transfusion programs after TIA have significantly reduced stroke risk, indicating TIA's importance as a warning sign [85,89,91].…”

Brain Volumes and Cognition in Patients with Sickle Cell Anaemia: A Systematic Review and Meta-Analysis

“…However, no association between TCD and IQ was found in older SCA children [ 8 , 9 ]. Investigations into MRI abnormalities have reported an association between IQ and SCI or lacunae, but the association diminished when age was added as a covariate [ 10 ]. Cognitive decline in sickle cell anaemia patients persisted even in the absence of SCI [ 4 ].…”