Browsing by Author "Hollis, Asha"

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    Bilateral actigraphic quantification of upper extremity movement in hemiparetic children with perinatal stroke: a case control study
    (2021-12-16) Hollis, Asha; Cole, Lauran; Zewdie, Ephrem; Metzler, Megan J.; Kirton, Adam
    Abstract Background Hemiparetic cerebral palsy impacts millions of people worldwide. Assessment of bilateral motor function in real life remains a major challenge. We evaluated quantification of upper extremity movement in hemiparetic children using bilateral actigraphy. We hypothesized that movement asymmetry correlates with standard motor outcome measures. Methods Hemiparetic and control participants wore bilateral wrist Actiwatch2 (Philips) for 48 h with movement counts recorded in 15-s intervals. The primary outcome was a novel statistic of movement asymmetry, the Actigraphic Movement Asymmetry Index (AMAI). Relationships between AMAI and standard motor outcomes (Assisting Hand Assessment, Melbourne Assessment, and Box and Block Test [BB]) were explored with Pearson or Spearman correlation. Results 30 stroke (mean 11 years 2 months (3 years 10 months); 13 female, 17 male) and 23 control (mean 11 years 1 month (4 years 5 months); 8 female, 15 male) were enrolled. Stroke participants demonstrated higher asymmetry. Correlations between AMAI and standard tests were moderate and strongest during sleep (BB: r = 0.68, p < 0.01). Conclusions Standard tests may not reflect the extent of movement asymmetry during daily life in hemiparetic children. Bilateral actigraphy may be a valuable complementary tool for measuring arm movement, potentially enabling improved evaluation of therapies with a focus on child participation.
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    The PSTIM Trial: Pediatric Transcranial Static Magnetic Field Stimulation to Improve Motor Learning
    (2019-05-30) Hollis, Asha; Kirton, Adam; Zewdie, Ephrem Takele; Condliffe, Elizabeth G.; Dukelow, Sean P.
    Non-invasive neuromodulation is an emerging therapy for children with early brain injury but is difficult to apply to preschoolers where windows of developmental plasticity are optimal. Transcranial static magnetic field stimulation (tSMS) decreases motor cortex excitability in adults but effects on the developing brain are unstudied. We aimed to determine the effects of tSMS on primary motor cortex (M1) excitability and motor learning in healthy children. Our randomized, sham-controlled, double-blinded, 3-arm, cross-over interventional trial enrolled 24 typically developing school-aged children. We used a linear mixed effects model to examine intervention effects over time. Our results demonstrated that tSMS modulates motor learning. Contralateral (right) tSMS inhibited early motor learning in the trained hand (p<0.01) while ipsilateral (left) tSMS facilitated later stages of motor learning (p<0.01). We did not observe changes in cortical excitability as assessed by transcranial magnetic stimulation (TMS) generated motor-evoked potential (MEP) amplitudes and intracortical neurophysiology paradigms. We demonstrated the feasibility, safety, and favourable tolerability of tSMS in a pediatric population. We conclude that tSMS over motor cortex can modulate motor learning in children with effects specific to both the hemisphere of stimulation and stage of learning. Our findings suggest therapeutic potential for tSMS neuromodulation in young children with cerebral palsy (CP).