Executive function and neural activation in adults with β‐thalassemia major: an event‐related potentials study

Abstract

In recent years, there has been growing interest in understanding the involvement of the nervous system and neurological complications in β-thalassemia major (β-TM). Several reports have demonstrated β-TM-related neurological abnormalities, and these have been postulated to be responsible for impaired cognitive and neuropsychological functioning. We investigated neural correlates of cognitive function in adults with β-TM and healthy controls using scalp-recorded event-related potentials (ERPs). To date, there have been no ERP studies in β-TM adult patients. We identified ERP correlates of executive function by using a complex task-switching paradigm in which participants have to quickly and effectively switch between two different task sets. The results indicated poorer cognitive performance of β-TM patients, resulting in overall higher error rates, longer response times, and increased switch costs compared with controls. Hemoglobin levels were negatively correlated with error rates and response times. Electrophysiological results indicated significant alterations in peak amplitudes of the ERP components P1, N1, and P2 in β-TM patients relative to controls. P2 amplitude correlated with hemoglobin levels. This novel investigation of executive function and related brain mechanisms and dynamics in adults with β-TM underscores the usefulness of ERP methodology as a sensitive measure for the study of neurocognitive processes in β-TM.

Attention, response inhibition and brain event‐related potential alterations in adults with beta‐thalassaemia major

“…β‐TM patients exhibited augmentation of P1 and N1 and P3 amplitudes to Go stimuli and P1, N2 and P3 amplitudes to Stop stimuli than healthy controls. This is in line with our other study, which also found P1 and N1 augmentation in β‐TM patients, despite the use of a different task with different cognitive demands (Raz et al , ). A possible interpretation of the present results is that β‐TM patients need to recruit additional brain resources, relative to healthy individuals, when dealing with cognitive challenge, such as the stop‐signal task.…”

“…The present study is part of a series of studies aimed at examining neural correlates of cognitive function in adults with TDT β‐TM using the ERP technique. We have recently found that impaired task switching ability is associated with early ERPs alterations among adult patients (Raz et al , ). In the present study we sought to identify behavioural and brain correlates of attention and response inhibition functions by using a stop‐signal task in which participants have to quickly and effectively respond to frequent Go stimuli while withholding their response when a Go stimulus is immediately followed by a stop sign.…”

“…Notably, the few existing studies of cognitive function in β‐TM were done almost exclusively on children and adolescents (Economou et al , ; Karimi et al , ; Shehata et al , , ; Duman et al , ; Raafat et al , ; El‐Alameey et al , ). To our knowledge, only three studies have assessed cognitive function in adults with β‐TM (Monastero et al , ; Raz et al , ,), showing marked reduction in cognitive performance in those patients when compared with healthy controls. Monastero et al () reported differences between β‐TM patients and controls using comprehensive neuropsychological battery including tests of memory, language, abstract reasoning, executive functions, attention and constructional/visuospatial skills.…”

“…Monastero et al () reported differences between β‐TM patients and controls using comprehensive neuropsychological battery including tests of memory, language, abstract reasoning, executive functions, attention and constructional/visuospatial skills. Raz et al (,) have found poorer performance of β‐TM patients on several intelligence subtests, which resulted in lower total performance IQ scores compared to controls; as well as significantly lower performance on a complex switching task.…”

Protein C and Protein S Levels in β-Thalassemia Major Patients in Erbil, Kurdistan Region

“…The exposure of phosphatidylserine on red blood cells is highly associated with the expression of platelet activation markers. Red blood cells exposed to phosphatidylserine may also directly cause the vascular damage detected in thalassemia (5).…”