Pontine Tegmentum Lesions Accompanying Myelitis During an Enterovirus Outbreak: Differential Diagnosis and Outcome

AIM: To investigate etiology and prognostic significance of pontine tegmentum lesions accompanying a cluster of acute flaccid myelitis. METHOD: We retrospectively examined patients from 6 centers in Turkey who manifested encephalitis or myelitis associated with dorsal pontine lesions on magnetic resonance imaging (MRI) between July 2018 and February 2019. RESULTS: Twenty-two patients were evaluated. Ten of 22 (45%) presented with acute paralysis and 12 of 22 (55%) with brainstem symptoms only. Reverse transcription polymerase chain reaction for enterovirus was positive in 2 patients' respiratory tract. Other etiologic factors were detected in 10 cases. On follow-up, patients presenting with symptoms of myelitis developed motor sequalae although spinal cord lesions on MRI resolved in 5 of 9 (55%). Encephalitic symptoms, present in 17 cases, recovered in 13 (76%), and brain MRI showed complete or near-complete resolution in 11 of 14 (78%). CONCLUSION: Various etiologic agents can be detected in patients with pontine involvement, even in a series collected during an outbreak of EV-D68. Encephalitis has a fair outcome but clinical recovery is slow and motor sequalae are frequent in spinal involvement, irrespective of follow-up spinal MRI findings.