Routes of Spread and Natural Progression in Acute Flaccid Myelitis

Acute Flaccid Myelitis (AFM) is a rare disease with varying presentations and prognoses. Our 82-patient cohort with AFM provides a unique opportunity to characterize patterns of motor involvement and evaluate associations with outcomes.

A retrospective analysis was conducted for 82 patients diagnosed with AFM. Patients were divided into the following four groups based on the patterns of weakness: group 1 (bilateral arms or legs), group 2 (hemi-contralateral, upper extremity to contralateral lower extremity), group 3 (hemi-ipsilateral, upper to lower extremity), and group 4 (global, all four limbs). Eleven patients with isolated limb weakness and two with mixed patterns were excluded. We analyzed demographics, illness progression, ventilatory status, and ambulation status. Statistical methods included paired t-tests and Freeman-Halton extension Fisher analysis.

Group sizes and mean ages were as follows: group 1 (N = 11, 4.5 ± 3.1 years), group 2 (N = 15, 5.5 ± 3.8 years), group 3 (N = 9, 5.0 ± 3.5), and group 4 (N = 34, 4.6 ± 3.3 years). The only statistically significant finding across groups was ambulation status (P < 0.05); all patients in group 1 were ambulatory.

AFM can be classified into four distinct motor patterns, which may help predict prognosis. Ambulation was significantly associated with pattern of involvement, supporting the value of pattern recognition in clinical assessment.