A Feasibility Study on the Efficacy of Functional Near-Infrared Spectrometry (fNIRS) to Measure Prefrontal Activation in Paediatric HIV

Abstract

Human immunodeficiency virus (HIV) infection is associated with disturbed neurotransmission and aberrant cortical networks. Although advances in the imaging of brain microarchitecture following neuroHIV has added to our knowledge of structural and functional changes associated with HIV, no data exists on paediatric HIV using optical neuroimaging techniques. This study investigated the feasibility of optical neuroimaging in paediatric HIV using functional near-infrared spectrometry (fNIRS). We measured prefrontal brain activation while participants executed a sustained attention task. We specifically tested whether patients living with HIV and study controls could perform the study protocol and whether we could measure the typical fNIRS haemodynamic response associated with neuronal activity. Eighteen participants (10 HIV participants, mean age: 13.9, SD = 1.66 years; 8 controls, mean age: 14.8, SD = 1.28 years), matched for sex, grade, and socio-economic status, were included in the study. All participants completed the Stroop colour word test (SCWT). Oxygenated haemoglobin concentration and the deoxygenated haemoglobin signal were recorded from the dorsolateral prefrontal cortex and the frontopolar area (FA) using fNIRS. The control group performed significantly better in terms of reaction time on the congruent and incongruent condition (congruent: t (16) = −3.36, <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" id="M1"><a:mi>p</a:mi><a:mo>&lt;</a:mo><a:mn>0.05</a:mn></a:math> : incongruent: <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" id="M2"><c:mi>p</c:mi><c:mtext> </c:mtext><c:mo>&lt;</c:mo><c:mn>0.05</c:mn></c:math> ). A pooled group analysis of the sample indicated significant activation in the DLPF and FA to the congruent condition of the SCWT ( <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" id="M3"><e:mi>p</e:mi><e:mo>&lt;</e:mo><e:mn>0.05</e:mn></e:math> ). Although cortical activation was noted in the DLPF and the FA in each of the groups when analysed independently, this neural activation did not reach statistical significance. The results show promise that fNIRS techniques are feasible for assessing prefrontal cortical activity in paediatric HIV. Future studies should seek to reduce the signal-to-noise ratio and consider inter-individual variability when measuring prefrontal activation in paediatric samples.