ABSTRACT

Childhood cancer and its treatment puts survivors at risk of low working memory capacity. Working memory represents a core cognitive function, which is crucial in daily life and academic tasks. The aim of this functional MRI (fMRI) study was to examine the working memory network of survivors of childhood cancer without central nervous system (CNS) involvement and its relation to cognitive performance. Thirty survivors (aged 7–16 years, ≥ 1 year after cancer treatment) and 30 healthy controls performed a visuospatial working memory task during MRI, including a low- and a high-demand condition. Working memory performance was assessed using standardized tests outside the scanner. When cognitive demands increased, survivors performed worse than controls and showed evidence for slightly atypical working memory-related activation. The survivor group exhibited hyperactivation in the right-hemispheric superior parietal lobe (SPL) in the high- compared to the low-demand working memory condition, while maintaining their performance levels. Hyperactivation in the right SPL coincided with poorer working memory performance outside the scanner in survivors. Even in survivors of childhood cancer without CNS involvement, we find neural markers pointing toward late effects in the cerebral working memory network.

Abbreviations

fMRI: Functional magnetic resonance imaging; CNS: Central nervous system; MNI: Montreal Neurological Institute; SES: Socioeconomic status; SPL: Superior parietal lobe

摘要

儿童癌症及其治疗使幸存者面临工作记忆能力低下的风险。工作记忆是一种核心认知功能，在日常生活和学习任务中至关重要。这项功能性 MRI (fMRI) 研究的目的是检查没有中枢神经系统 (CNS) 参与的儿童癌症幸存者的工作记忆网络及其与认知能力的关系。30 名幸存者（7-16 岁，癌症治疗后≥1 年）和 30 名健康对照者在 MRI 期间执行了视觉空间工作记忆任务，包括低需求和高需求条件。使用扫描仪外的标准化测试评估工作记忆性能。当认知需求增加时，幸存者的表现比对照组差，并显示出与工作记忆相关的轻微非典型激活的证据。与低需求工作记忆条件相比，幸存者组表现出右半球上顶叶 (SPL) 的过度激活，同时保持其性能水平。右侧 SPL 中的过度激活与幸存者在扫描仪外较差的工作记忆性能相吻合。即使在没有中枢神经系统受累的儿童癌症幸存者中，我们也发现神经标记指向大脑工作记忆网络的晚期效应。

缩写

fMRI：功能磁共振成像；CNS：中枢神经系统；MNI：蒙特利尔神经学研究所；SES：社会经济地位；SPL：上顶叶