title: The role of prefrontal cortex during postural control in Parkinsonian syndromes a functional near-infrared spectroscopy study.
abstract: Postural instability represents a main source of disability in Parkinsonian syndromes and its pathophysiology is poorly understood. Indirect probes (i.e., mental imagery) of brain involvement support the role of prefrontal cortex as a key cortical region for postural control in older adults with and without Parkinsonian syndromes. Using functional near infrared spectroscopy (fNIRs) as a direct online cortical probe, this study aimed to compare neural activation patterns in prefrontal cortex, postural stability, and their respective interactions, in (1) patients with Parkinsonian syndromes; (2) those with mild parkinsonian signs; (3) and healthy older adults. Among 269 non-demented older adults (76.41 ± 6.70 years, 56% women), 26 individuals presented with Parkinsonian syndromes (Unified Parkinson's disease rating scale (UPDRS): 11.08 ± 3.60), 117 had mild parkinsonian signs (UPDRS: 3.21 ± 2.49), and 126 individuals were included as a healthy control group. Participants were asked to stand upright and count silently for ten seconds while changes in oxygenated hemoglobin levels over prefrontal cortex were measured using fNIRs. We simultaneously evaluated postural stability with center of pressure velocity data recorded on an instrumented walkway. Compared to healthy controls and patients with mild parkinsonian signs, patients with Parkinsonian syndromes demonstrated significantly higher prefrontal oxygenation levels to maintain postural stability. The pattern of brain activation and postural control of participants with mild parkinsonian signs were similar to that of normal controls. These findings highlight the online role of the prefrontal cortex in postural control in patients with Parkinsonian syndromes and afford the opportunity to improve therapeutic options for postural instability.
authors.affiliation: Department of Neurology, Division of Cognitive & Motor Aging, Albert Einstein College of Medicine, Bronx, NY, USA; Ferkauf Graduate of Psychology, Yeshiva University, Bronx, NY, USA.
authors.forename: Jeannette R
authors.initials: JR
authors.lastname: Mahoney
authors.affiliation: Department of Neurology, Division of Cognitive & Motor Aging, Albert Einstein College of Medicine, Bronx, NY, USA; Ferkauf Graduate of Psychology, Yeshiva University, Bronx, NY, USA.
authors.forename: Roee
authors.initials: R
authors.lastname: Holtzer
authors.affiliation: Drexel University School of Biomedical Engineering, Philadelphia, PA, USA.
authors.forename: Meltem
authors.initials: M
authors.lastname: Izzetoglu
authors.affiliation: Ferkauf Graduate of Psychology, Yeshiva University, Bronx, NY, USA.
authors.forename: Vance
authors.initials: V
authors.lastname: Zemon
authors.affiliation: Department of Neurology, Division of Cognitive & Motor Aging, Albert Einstein College of Medicine, Bronx, NY, USA.
authors.forename: Joe
authors.initials: J
authors.lastname: Verghese
authors.affiliation: Department of Neurology, Division of Cognitive & Motor Aging, Albert Einstein College of Medicine, Bronx, NY, USA; Department of Clinical Neurosciences, Geneva University Hospitals and University of Geneva, Geneva, Switzerland. Electronic address: gilles.allali@hcuge.ch.
authors.forename: Gilles
authors.initials: G
authors.lastname: Allali
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D020734:Parkinsonian Disorders / Q000503:physiopathology*; D004856:Postural Balance / Q000502:physiology*; D017397:Prefrontal Cortex / Q000503:physiopathology*; D019265:Spectroscopy, Near-Infrared
keywords: Aging; Functional near infrared spectroscopy; Parkinsonian syndromes; Postural control; Prefrontal cortex