(13) Safety and Feasibility of Transcranial Magnetic Stimulation in Infants with Perinatal Brain Injury

Background: Cerebral Palsy (CP) often results from perinatal brain injury and affects movement, balance, and coordination. Understanding neurodevelopment post-injury is crucial for early CP diagnosis and rehabilitation during heightened neural plasticity. While Transcranial Magnetic Stimulation (TMS) effectively measures motor excitability and plasticity in pediatric CP, its application in infants is underexplored. This report provides insights into the safety and feasibility of TMS in infants with perinatal brain injury.

Objectives: To assess the safety and feasibility of single-pulse TMS (spTMS) in infants aged 0-2 years with perinatal brain injuries to evaluate the cortical excitability and functional integrity of the corticospinal tract (CST).

Design/Methods: Participants underwent 1-3 visits at discrete time points during early development (3-6 months, 12 months ± 1 month, or 18 months ± 1 month). spTMS measured motor-evoked potentials (MEPs) by stimulating the primary motor cortex. Safety and feasibility were monitored by physiological parameters, the Modified Behavioral Pain Scale (MBPS), and caregiver feedback.

Results: We evaluated the impact of spTMS on heart rate (HR), respiratory rate (RR), and pain response using the MBPS in 19 infants (mean age 8.75 ± 5.12 months) with perinatal brain injury across 35 spTMS sessions, delivering a cumulative total of 1887 pulses. Pre and post-spTMS outcomes were compared using linear mixed-effects models (LMEM) to account for repeated measures within infants. There were no significant changes in HR (β = -0.51 bpm, p = 0.81) or RR (β = -0.69 breaths/min, p = 0.66) post-spTMS. MBPS scores significantly increased (β = 0.57, p = 0.046, mean difference = 0.57). 235 MEPs were identified in 17 participants, indicating that 12.5% of pulses resulted in an MEP.

Conclusion: This study demonstrates the safety and feasibility of using spTMS to assess CST integrity and excitability in infants with perinatal brain injury. spTMS does not significantly affect physiological parameters. MBPS scores were significantly increased after spTMS. The clinical importance of the effect size is unknown and further investigations are required to validate the MBPS’s capacity to differentiate between pain and non-pain-related distress. The identification of MEPs in most participants supports the utility of spTMS in evaluating CST integrity. In the absence of significant adverse events across 1887 TMS pulses, these findings underscore the potential for broader application of spTMS in early neurodevelopmental research.