A Systematic Review of Cerebral Functional Near-Infrared Spectroscopy in Chronic Neurological Diseases—Actual Applications and Future Perspectives

Abstract

Background: The management of people affected by age-related neurological disorders requires the adoption of targeted and cost-effective interventions to cope with chronicity. Therapy adaptation and rehabilitation represent major targets requiring long-term follow-up of neurodegeneration or, conversely, the promotion of neuroplasticity mechanisms. However, affordable and reliable neurophysiological correlates of cerebral activity to be used throughout treatment stages are often lacking. The aim of this systematic review is to highlight actual applications of functional Near-Infrared Spectroscopy (fNIRS) as a versatile optical neuroimaging technology for investigating cortical hemodynamic activity in the most common chronic neurological conditions. Methods: We reviewed studies investigating fNIRS applications in Parkinson’s Disease (PD), Alzheimer’s Disease (AD) and Mild Cognitive Impairment (MCI) as those focusing on motor and cognitive impairment in ageing and Multiple Sclerosis (MS) as the most common chronic neurological disease in young adults. The literature search was conducted on NCBI PubMed and Web of Science databases by PRISMA guidelines. Results: We identified a total of 63 peer-reviewed articles. The AD spectrum is the most investigated pathology with 40 articles ranging from the traditional monitoring of tissue oxygenation to the analysis of functional resting-state conditions or cognitive functions by means of memory and verbal fluency tasks. Conversely, applications in PD (12 articles) and MS (11 articles) are mainly focused on the characterization of motor functions and their association with dual-task conditions. The most investigated cortical area is the prefrontal cortex, since reported to play an important role in age-related compensatory mechanism and neurofunctional changes associated to these chronic neurological conditions. Interestingly, only 9 articles applied a longitudinal approach. Conclusion: The results indicate that fNIRS is mainly employed for the cross-sectional characterization of the clinical phenotypes of these pathologies, whereas data on its utility for longitudinal monitoring as surrogate biomarkers of disease progression and rehabilitation effects are promising but still lacking.

fNIRS-derived neurocognitive ratio as a biomarker for neuropsychiatric diseases

“… 9 , 90 , and 91 , specifically in autism, 14 and its role in neurofeedback, 92 in pain, 93 and in neurology. 94 Only a handful of them are listed in Table 9 . This study is the first in several aspects: (1) to show a high specificity of fNIRS for various types of neuropsychiatric diseases (more than 2); (2) in providing an fNIRS-derived biomarker (namely the NCR ) with very high accuracy that is also clinically relevant; and (3) in that it does not attempt to find a correlation between behavioral data and physiological data, rather it combines them since behavior cannot be produced without physiological activation.…”

fNIRS-derived Neurocognitive Ratio as a Biomarker for Neuropsychiatric Diseases

“…Several studies actually achieved this ambitious goal set by Ehlis et al For a good review of use of fNIRS in psychiatry, please see, 58,78,79 specifically in autism, 61 its role in neurofeedback, 80 in pain, 81 and in neurology. 82 Only a handful of them are listed in Table 1. This study is the first in several aspects: 1) to show a high specificity of fNIRS for various types of neuropsychiatric diseases (more than 2), 2) in providing an fNIRS derived biomarker (namely the NCR ) with very high accuracy that is also clinically relevant, and 3) in that it does not attempt to find a correlation between behavioral data and physiological data, rather it combines them since behavior cannot be produced without physiological activation.…”

“…58 Several studies actually achieved this ambitious goal set by Ehlis et al For a good review of use of fNIRS in psychiatry, please see, 58,78,79 specifically in autism, 61 its role in neurofeedback, 80 in pain, 81 and in neurology. 82 Only a handful of them are listed in Table 1. This study is the first in several aspects: 1) to show a high specificity of fNIRS for various types of neuropsychiatric 17…”

Are Sarcopenia and Cognitive Dysfunction Comorbid after Stroke in the Context of Brain–Muscle Crosstalk?

“…Functional Near-Infrared Spectroscopy (fNIRS) is a neuroimaging technique that is non-invasive, cost-effective, safe, rapid to set up, portable, and non-motion-sensitive [ 76 ]. Due to these advantages, fNIRS has been widely used in studies of particular clinical populations, such as Alzheimer’s disease, depression, and other chronic neurological disorders [ 77 ]. fNIRS maps neuronal activity by applying near-infrared spectrum light that can travel through tissue.…”