Characteristics of Upper Extremity Recovery in Acute Flaccid Myelitis: A Case Series.

BACKGROUND Clinical characteristics and timing associated with nonsurgical recovery of upper extremity function in acute flaccid myelitis (AFM) are unknown. METHODS A single institution retrospective case series was analyzed to describe clinical features of AFM diagnosed between October 2013 and December 2016. Patients were consecutively sampled children with a diagnosis of AFM who were referred to a hand surgeon. Patient factors and initial severity of paralysis were compared with upper extremity muscle strength outcomes using the Medical Research Council Scale every three months up to 18 months post-onset. RESULTS Twenty-two patients with AFM (age 2-16 years) were studied. Proximal upper extremity musculature was more frequently and severely affected, with 56% of patients affected bilaterally. Functional recovery of all muscle groups (≥M3) in an individual limb was observed in 43% of upper extremities within three months. Additional complete limb recovery to ≥M3 after three months was rarely observed. Extraplexal paralysis, including spinal accessory (72%), glossopharyngeal / hypoglossal (28%), lower extremity (28%), facial (22%), and phrenic nerves (17%), was correlated with greater severity of upper extremity paralysis and decreased spontaneous recovery. There was no correlation between severity of paralysis or recovery and patient characteristics including age, sex, comorbidities, prodromal symptoms, or time to paralysis. CONCLUSIONS Spontaneous functional limb recovery, if present, occurred early, within three months of the onset of paralysis. We recommend that patients without signs of early recovery warrant consideration for early surgical intervention and referral to a hand surgeon or other specialist in peripheral nerve injury.