Background: Acute flaccid myelitis has emerged as the leading cause of acute flaccid paralysis in children. Acute flaccid myelitis leads to significant physical disability; hence, objective outcome measures to study disease severity and progression are desirable. In addition, nerve transfer to improve motor function in affected children needs further study.
Methods: Retrospective study of acute flaccid myelitis subjects managed at Children's Healthcare of Atlanta from August 2014 to December 2019. Clinical, electromyography and nerve conduction study, neuropsychological functional independence (WeeFIM), and nerve transfer data were reviewed.
Results: Fifteen children (11 boys and 4 girls) mean age 5.1±3.2 years (range 14 months to 12 years) were included. All subjects (n = 15) presented with severe asymmetric motor weakness and absent tendon reflexes. Motor nerve conduction study of the affected limbs in 93% (n = 14) showed absent or markedly reduced amplitude. Ten patients received comprehensive inpatient rehabilitation and neuropsychological evaluation. Admission and discharge WeeFIM scores showed deficits most consistent and pronounced in the domains of self-care and mobility. Multiple nerve transfer surgery was performed on 13 limbs (9 upper and 4 lower extremities) in 6 children. Postsurgery (mean duration of 10.4 ± 5.7 months) follow-up demonstrated improvement on active movement scale (AMS) in 4 subjects.
Conclusion: Acute flaccid myelitis affects school-age children with asymmetric motor weakness, absent tendon reflexes, and reduced or absent motor amplitude on nerve conduction study. Comprehensive rehabilitation and nerve transfer led to improvement in motor function on neuropsychology WeeFIM and AMS scores.
Keywords: Acute flaccid paralysis; EMG/NCS; WeeFIM; active movement scale; acute flaccid myelitis; nerve transfer.