Letters to the Editor
To the Editors:
We read with interest the article by Knoester et al1 overviewing cases of enterovirus D68 (EV-D68)-related acute flaccid myelitis (AFM). Herein, we describe the case of a 6-year-old boy who suffered from AFM associated with EV-D68. He was admitted to an emergency hospital due to dysphagia and flaccid limb paralysis. Magnetic resonance imaging revealed a brainstem and cervical spine hyperintense region on T2-weighted and FLAIR images (Fig. 1). EV-D68 was detected from his pharynx after admission. Thus, he was diagnosed with AFM due to EV-D68. He was unable to sit alone, hold his head and swallow.
Although methylprednisolone pulse therapy and intravenous immunoglobulin therapy had been performed, his symptoms did not improve. Thus, he was transferred to our hospital on the ninth day after onset.
After a second round of methylprednisolone pulse therapy, rehabilitation of swallowing and motor function was started. Magnetic resonance imaging on the third day after the second course of methylprednisolone pulse therapy showed mildly improved abnormal signals. His limb paralysis gradually improved with rehabilitation. He was able to walk alone on the 45th day after onset. However, dysphagia persisted without improvement. The video fluoroscopic swallowing examination (VFSE) performed on the 24th day after onset demonstrated a loss of swallowing movement. Swallowing rehabilitation was continued, and a second VFSE was repeated 52 days after onset. Tongue movement was improved, which enabled food to reach the larynx, whereas inflow into the esophagus was not achieved. We considered that the insufficient relaxation of the cricopharyngeal muscle was a major cause of dysphagia, so we started oral baclofen of 5 mg per day after the second VFSE. After starting baclofen, swallowing function began improving. In the third VFSE performed 80 days after onset, inflow into the esophagus was observed (Fig. 2). Doses were increased to 10 mg per day, enabling the patient to feed orally at 89 days after onset.
EV-D68-associated AFM was prevalent in North America in 2014,2 with some patients showing central nervous symptom complications. Immune-mediated therapy was given for symptoms, while treatment response was poor along with neurologic prognosis. Dysphagia as well as other neurologic sequelae persisted in most cases, whereas only a few reports describe an improvement in swallowing function after surgery.3 A report described that oral baclofen was effective for treating dysphagia caused by a brainstem disorder.4 Similarly, in our patient, dysphagia improved with oral baclofen. We speculate that cricopharyngeal muscle spasticity improved with baclofen, which allowed the passage of food through the esophagus.
Although more case studies are needed, oral baclofen for dysphagia is less invasive and should be considered as a useful option for cases with dysphagia due to brainstem disorder in EV-D68-associated AFM.
Yuichi Tateishi, MD
Nobutsune Ishikawa, PhD
Hiroo Tani, MD
Yoshiyuki Kobayashi, MD
Masao Kobayashi, PhD
Department of Pediatrics
Hiroshima University Hospital
1. Knoester M, Helfferich J, Poelman R, et al. Twenty-nine cases of enterovirus-D68–associated acute flaccid myelitis in Europe 2016. Pediatr Infect Dis J. 2019;38:16–21.
2. Messacar K, Abzug MJ, Dominguez SR. 2014 outbreak of enterovirus D68 in North America. J Med Virol. 2016;88:739–745.
3. Takafumi T, Hironori B, Meiko K, et al. Surgical treatment of enterovirus D68 brainstem encephalitis-induced dysphagia. Auris Nasus Larynx. 2018;45:1093–1097
4. Hiroshi T, Kazuko A, Hiroshi T, et al. Effectiveness of rehabilitation and the baclofen for dysphagia with dysfunction of cricopharyngeal muscle in the patient with lateral medullary syndrome—a case report (Japanese). J Clin Rehabil. 2009;18:760–764