Altered spontaneous cortical activity predicts pain perception in individuals with cerebral palsy

Abstract

Cerebral palsy is the most common pediatric neurological disorder and results in extensive impairment to the sensorimotor system. However, these individuals also experience increased pain perception, resulting in decreased quality of life. In the current study, we utilized magnetoencephalographic brain imaging to examine whether alterations in spontaneous neural activity predict the level of pain experienced in a cohort of 38 individuals with spastic diplegic cerebral palsy and 67 neurotypical controls. Participants completed five minutes of an eyes closed resting-state paradigm while undergoing a magnetoencephalography recording. The magnetoencephalographic data were then source imaged, and the power within the delta (2–4 Hz), theta (5–7 Hz), alpha (8–12 Hz), beta (15–29 Hz), low gamma (30–59 Hz), and high gamma (60–90 Hz) frequency bands were computed. The resulting power spectral density maps were analyzed vertex-wise to identify differences in spontaneous activity between groups. Our findings indicated that spontaneous cortical activity was altered in the participants with cerebral palsy in the delta, alpha, beta, low gamma, and high gamma bands across the occipital, frontal, and secondary somatosensory cortical areas (all pFWE < 0.05). Furthermore, we also found that the altered beta band spontaneous activity in the secondary somatosensory cortices predicted heightened pain perception in the individuals with cerebral palsy (p = 0.039). Overall, these results demonstrate that spontaneous cortical activity within individuals with cerebral palsy is altered in comparison to their neurotypical peers and may predict increased pain perception in this patient population. Potentially, changes in spontaneous resting-state activity may be utilized to measure the effectiveness of current treatment approaches that are directed at reducing the pain experienced by individuals with cerebral palsy.

Aberrant age-related alterations in spontaneous cortical activity in participants with cerebral palsy

“…The Trevarrow et al ( 30 ) dataset used in this investigation was comprised of 105 participants ( 30 ). Thirty-eight of the participants had spastic diplegic CP (GMFCS I-IV, Mean Age = 22.08 ± 10.46 yrs., Age Range = 9.80–47.50 yrs., Females = 20) and 67 were NT controls (Mean Age = 19.56 ± 10.25 yrs., Age Range = 9.08–49.40 yrs., Females = 27).…”

“…In addition, none of the participants had a prior history of epilepsy or mood disorders. As indicated in Trevarrow et al ( 30 ), informed consent was acquired, and the youth assented to participate in the experiment. Furthermore, the local Institutional Review Board reviewed and approved the study, and all protocols were in accordance with the declaration of Helsinki.…”

“…Complete details of the MEG acquisition, pre-processing and source imaging are found in Trevarrow et al ( 30 ). Briefly, a 306-sensor Elekta/MEGIN MEG system (Helsinki, Finland) was used to sampled continuously at 1 kHz as the participants completed a resting state paradigm with their eyes closed for 5 minutes.…”

“…As in Trevarrow et al ( 30 ), minimum norm estimates were computed and normalized by a dynamic statistical parametric mapping (dSPM) algorithm for source imaging. An empty room recording to compute a noise covariance matrix for source imaging was utilized to account for environmental noise ( 38 ).…”

“…The overall goal of this investigation was to evaluate the age-related changes seen in the spontaneous cortical activity of persons with CP. This goal was accomplished by evaluating the MEG eyes-closed resting-state recordings collected by Trevarrow and colleagues that initially identified that the spontaneous cortical activity for persons with CP is uncharacteristic when compared with NT controls ( 30 ). Since the clinical literature has reported that most adults with CP between the ages of 20 and 40 years will experience some form of premature aging, we hypothesized that the persons with CP would have aberrant age-related changes in the linear trajectory of their spontaneous cortical activity when compared to NT controls.…”