Motor Evoked Potentials as Potential Biomarkers of Early Atypical Corticospinal Tract Development in Infants with Perinatal Stroke.

Jesse L Kowalski,Marie Hickey,Mo Chen,Kyle Rudser,Raghavendra Rao,Colleen Peyton,Elizabeth Zorn,Samuel T Nemanich,Bernadette T Gillick,Tanjila Nawshin,Michael Georgieff

doi:10.3390/jcm8081208

Abstract

Diagnosis of cerebral palsy (CP) after perinatal stroke is often delayed beyond infancy, a period of rapid neuromotor development with heightened potential for rehabilitation. This study sought to assess whether the presence or absence of motor evoked potentials (MEPs) elicited by transcranial magnetic stimulation (TMS) could be an early biomarker of atypical development within the first year of life. In 10 infants with perinatal stroke, motor outcome was assessed with a standardized movement assessment. Single-pulse TMS was utilized to assess presence of MEPs. Younger infants (3–6 months CA, n = 5, 4/5 (80%)) were more likely to present with an MEP from the more-affected hemisphere (MAH) compared to older infants (7–12 months CA, n = 5, 0/5, (0%)) (p = 0.048). Atypical movement was demonstrated in the majority of infants with an absent MEP from the MAH (5/6, 83%) compared to those with a present MEP (1/4, 25%) (p = 0.191). We found that age influences the ability to elicit an MEP from the MAH, and motor outcome may be related to MAH MEP absence. Assessment of MEPs in conjunction with current practice of neuroimaging and motor assessments could promote early detection and intervention in infants at risk of CP.

Highlights

Perinatal stroke, occurring between 20 weeks’ gestation and the 28th day of life, often leads to cerebral palsy (CP), a diagnosis of disordered movement due to a disturbance to the developing brain in utero or infancy [1,2,3]
The infants’ tolerance to transcranial magnetic stimulation (TMS) was determined based on previously reported safety assessments, follow up calls with no adverse events reported by parents 24 hours post-TMS assesssment, and no
As a means to determine whether motor evoked potentials (MEPs) absence may be an early biomarker of atypical corticospinal tract (CST) development within the first year of life, we assessed the prevalence of atypical movement and MEP responses to TMS in 10 infants with perinatal stroke

Summary

Introduction

Perinatal stroke, occurring between 20 weeks’ gestation and the 28th day of life, often leads to cerebral palsy (CP), a diagnosis of disordered movement due to a disturbance to the developing brain in utero or infancy [1,2,3]. Little is known about the time at which maladaptive neurodevelopment of the CST occurs after perinatal stroke, or its relationship with motor function within the first year of life and CP diagnosis. An estimated 68% of infants with perinatal stroke will eventually be diagnosed with CP, but the diagnosis of CP is often delayed until notable movement discrepancies become apparent, often at two years of age or greater [8,9]. We hypothesize that identification of neural biomarkers of atypical CST development in infants with perinatal stroke at risk of CP could be achieved through non-invasive brain assessments with transcranial magnetic stimulation (TMS)

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Discussion

Conclusion