Open AccessFunctional Near-Infrared Spectroscopy in the Study of Speech and Language Impairment Across the Life Span: A Systematic Review
Author(s) -
Lindsay K. Butler,
Swathi Kıran,
Helen TagerFlusberg
Publication year - 2020
Publication title -
american journal of speech-language pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.993
H-Index - 72
eISSN - 1558-9110
pISSN - 1058-0360
DOI - 10.1044/2020_ajslp-19-00050
Subject(s) - functional near infrared spectroscopy , systematic review , neuroimaging , psychology , dementia , aphasia , dysarthria , acquired brain injury , functional neuroimaging , autism spectrum disorder , audiology , functional magnetic resonance imaging , cognitive psychology , cognition , medline , autism , neuroscience , developmental psychology , rehabilitation , medicine , psychiatry , disease , prefrontal cortex , pathology , political science , law
Purpose Functional brain imaging is playing an increasingly important role in the diagnosis and treatment of communication disorders, yet many populations and settings are incompatible with functional magnetic resonance imaging and other commonly used techniques. We conducted a systematic review of neuroimaging studies using functional near-infrared spectroscopy (fNIRS) with individuals with speech or language impairment across the life span. We aimed to answer the following question: To what extent has fNIRS been used to investigate the neural correlates of speech-language impairment? Method This systematic review was preregistered with PROSPERO, the international prospective register of systematic reviews (CRD42019136464). We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol for preferred reporting items for systematic reviews. The database searches were conducted between February and March of 2019 with the following search terms: (a) fNIRS or functional near-infrared spectroscopy or NIRS or near-infrared spectroscopy, (b) speech or language, and (c) disorder or impairment or delay. Results We found 34 fNIRS studies that involved individuals with speech or language impairment across nine categories: (a) autism spectrum disorders; (b) developmental speech and language disorders; (c) cochlear implantation and deafness; (d) dementia, dementia of the Alzheimer's type, and mild cognitive impairment; (e) locked-in syndrome; (f) neurologic speech disorders/dysarthria; (g) stroke/aphasia; (h) stuttering; and (i) traumatic brain injury. Conclusions Though it is not without inherent challenges, fNIRS may have advantages over other neuroimaging techniques in the areas of speech and language impairment. fNIRS has clinical applications that may lead to improved early and differential diagnosis, increase our understanding of response to treatment, improve neuroprosthetic functioning, and advance neurofeedback.