Reproducibility of corticokinematic coherence

Abstract

Corticokinematic coherence (CKC) between limb kinematics and magnetoencephalographic (MEG) signals reflects cortical processing of proprioceptive afference. However, it is unclear whether strength of CKC is reproducible across measurement sessions. We thus examined reproducibility of CKC in a follow-up study. Thirteen healthy right-handed volunteers (7 females, 21.7 ± 4.3 yrs) were measured using MEG in two separate sessions 12.6 ± 1.3 months apart. The participant was seated and relaxed while his/her dominant or non-dominant index finger was continuously moved at 3 Hz (4 min for each hand) using a pneumatic movement actuator. Finger kinematics were recorded with a 3-axis accelerometer. Coherence was computed between finger acceleration and MEG signals. CKC strength was defined as the peak coherence value at 3 Hz form a single sensor among 40 pre-selected Rolandic gradiometers contralateral to the movement. Pneumatic movement actuator provided stable proprioceptive stimuli and significant CKC responses peaking at the contralateral Rolandic sensors. In the group level, CKC strength did not differ between the sessions in dominant (Day-1 0.40 ± 0.19 vs. Day-2 0.41 ± 0.17) or non-dominant (0.35 ± 0.16 vs. 0.36 ± 0.17) hand, nor between the hands. Intraclass-correlation coefficient (ICC) values indicated excellent inter-session reproducibility for CKC strength for both dominant (0.86) and non-dominant (0.97) hand. However, some participants showed pronounced inter-session variability in CKC strength, but only for the dominant hand. CKC is a promising tool to study proprioception in long-term longitudinal studies in the group level to follow, e.g., integrity of cortical proprioceptive processing with motor functions after stroke.

Symptom-Dependent Changes in MEG-Derived Neuroelectric Brain Activity in Traumatic Brain Injury Patients with Chronic Symptoms

“…The test-retest intervals in most studies are days to weeks. Recasens et al [47] report results from a 7-week interval and both Piitulainen et al [57] and Dunkley et al [48] report results for intervals greater than one year. Over all the reports, the maximum number of subjects was 40 [46].…”

“…These regions were selected because their baseline vs. 16-month follow-up correlations are typical and their difference values are significantly different from zero and visibly so in the figure . evoked response paradigms [44][45][46][47][48][49][50][51]. For free-running paradigms, most measures are for resting connectivity confined to frequency bands [52][53][54][55][56][57][58]. The test-retest intervals in most studies are days to weeks.…”

Investigations of the Somatosensory System with Magnetoencephalography

“…Studies demonstrated that CKC (i) is detectable in most investigated subjects with high level of coherence compared with, e.g., cortico-muscular coherence (CMC) that is detectable in about 60-70% of the subjects (Pohja et al, 2005), (ii) shows a high degree of inter-session reproducibility at the individual level (Piitulainen et al, 2018), and (iii) is robust against artifacts associated with implanted ferro-magnetic materials providing that the temporal signal space separation method is used to subtract the artifact from raw MEG signals (Bourguignon et al, 2016).…”

Attention directed to proprioceptive stimulation alters its cortical processing in the primary sensorimotor cortex

“…Therefore, the strength of CKC quantifies the degree of cortical proprioceptive processing and has shown to be associated with motor performance (Piitulainen, Seipäjärvi, et al., 2018b). The inter‐session reproducibility of CKC is shown to be excellent at the group level (Piitulainen, Illman, et al, 2018a; Piitulainen et al., 2020). CKC is thus a potential clinical tool to detect, examine and follow deficits in cortical proprioceptive processing, for example, in newborn using EEG (Smeds et al, 2017) or in motor impairments such as Friedreich ataxia using MEG (Marty et al., 2019).…”