Acute Flaccid Myelitis Paralysis Reversed in New Surgery

Two years post operation, 2 pediatric patients with acute flaccid myelitis (AFM) had their arm function and movement restored, according to a new report. Previously, the patients believed they would be paralyzed after their experience with the polio-like illness.

Investigators from the Hospital for Special Surgery (HSS) in New York treated 2 pediatric patients with nerve transfer in 3 limbs in an attempt create a medical intervention to alter AFM’s disease course. Between August 2014 and July 2015, the mean age of the patients affected by AFM was 7 years.

The investigators wrote that AFM is linked to the enterovirus D68 and can induce inflammation and the destruction of cervical anterior horn cells. Consequently, the disease causes abrupt onset motor weakness with preserved sensory function in 1 or both upper extremities.

Currently, there are no treatments for AFM. While there have been previous attempts to use steroids, plasma exchange, and intravenous immunoglobulin, they have had little to no neurological improvement. Antiviral medications have also seemed ineffective.

“We were most surprised that no viable treatment strategy existed to improve the function of patients affected by AFM,” study author Scott Wolfe, MD, told Rare Disease Report®. “We believe that surgical techniques developed for treatment of brachial plexus palsy in children and adults can be used successfully to restore function to paralyzed muscles in affected patients.”

Both of the pediatric patients involved in the case report had demonstrated significant or complete denervation of muscles. The investigators performed nerve transfers in 3 limbs and then measured muscle strength postoperatively in accordance with the British Medical Research Council scale, plus range of motion, and electromyography (EMG) testing.

The first patient, a 12-year-old male from New York State, presented with right greater than upper left extremity weakness. Eventually, he developed bilaterial upper extremity weakness, which progressed to the fingers and neck. He was brought to HSS after 8 months with the disease to undergo surgery, which involved the transfer of donor muscles from other sections of his own body.

After 3 months postop, the patient demonstrated “promising functional returns,” and by 2 years postop, EMG showed full biceps motor unit recruitment. After 35 months, the patient improved to full elbow flexation and shoulder rotation to 135 degrees.

The second patient was a 14-year-old Illinois female who experienced 9 months of upper extremity weakness followed by conjunctivitis and gastroenteritis. She was admitted to intensive care after developing severe neck pain that progressed to flaccid quadriparesis and respiratory failure. She underwent bilateral nerve transfer surgeries using donor muscle tissue from her own body.

After 10 months postop, she regained full right elbow flexation. After 21 months, EMG testing showed discrete recruitment of all 3 deltoid heads that were treated. After 32 months, she achieved near normal right brachialis strength and full recovery in her elbow’s range of motion. The study authors reported she had no functional loss related to the nerve transfers and maintained normal medial nerve function and shoulder adduction.

“With increased numbers of surgically treated patients, we can document outcomes on a larger scale and identify which nerve and tendon transfers offer the best hope for patients with AFM,” Wolfe concluded.

The paper, titled “Nerve Transfers for Enterovirus D68-Associated Acute Flaccid Myelitis: A Case Series” was published in the journal Pediatric Neurology.