Does acute flaccid myelitis cause respiratory failure in children?

Acute flaccid myelitis (AFM) is a rare disease that affects spinal cord gray matter, results in acute flaccid weakness of one or more limbs and predominantly involves the cervical spinal cord, which places patients at higher risk for respiratory failure. Our study aims to describe respiratory failure in pediatric AFM patients with emphasis on the need for assisted ventilation and respiratory nerve involvement from an acute and long-term perspective.

We reviewed the medical records of patients diagnosed with AFM seen in a multidisciplinary clinic for persistent limb weakness between 2016 and 2020.

We studied 54 patients, 35% were female. The median age of patients at illness onset was 5 years (range 7 months-19 years). The median age of patients at the time of study was 8.5 years (range 2-20 years). Eleven patients (20%) required assisted ventilation for acute respiratory failure. Of those that experienced acute respiratory failure, 81% developed chronic respiratory failure. Fifty-six percent of patients with chronic respiratory failure were able to wean off assisted ventilation by 1 year. All patients that experienced unilateral diaphragm impairment with AFM onset experienced acute and chronic respiratory failure.

Many patients with AFM may experience respiratory compromise and develop chronic respiratory failure. However, most of these patients can be weaned off ventilatory support by 1 year from illness onset. Most children with unilateral diaphragm impairment can sustain adequate ventilation without the need for long-term ventilatory support.