Effectiveness of multisensory stimulation and priming (MuSSAP) upper limb training in 3-8 months old infants with unilateral brain lesion - a retrospective clinical cohort study.

Introduction: Multi Sensory Stimulation And Priming (MuSSAP) is an early upper limb training for infants at high risk of unilateral cerebral palsy (CP). MuSSAP is designed to enhance awareness of the affected upper limb facilitating initiation of goal-directed movements. This study assesses the effectiveness of an 8-week MuSSAP training on manual ability in a clinical setting.

Participants And Methods: Twenty-eight infants (mean corrected age at T0: 5.0 months) were included in a retrospective clinical cohort study with assessments pre- (T0), post- (T1) and at 8-week follow-up (T2) using the Hand Assessment for Infants (HAI). The primary outcome was the HAI 'affected hand score', secondary outcomes included the 'unit score' and item 1 ('initiates to side'). Data were analysed using linear mixed models.

Results: HAI scores improved between T0-T1 (n = 25) for both affected hand score (estimate: 3.2, p < 0.001), and unit score (estimate: 9.7, p < 0.001). Scores remained stable between T1-T2. The number of infants who never initiated or only when restrained/sometimes initiated or only when prompted/almost always spontaneously initiated goal-directed movements changed from 8/13/7 at T0 to 5/5/15 at T1 (three missing). Of the five infants who did not initiate goal-directed movements after training, three had drug-resistant epilepsy.

Conclusion: MuSSAP appears to improve manual ability in infants at high risk of unilateral CP in a clinical setting. A larger randomized controlled trial incorporating brain-based measures is needed to further investigate its effectiveness and working mechanism, especially for infants who do not initiate goal-directed movements with the affected upper limb.