Unusual magnetic resonance findings in two children with sudden sensorineural hearing loss

Abstract

Sudden sensorineural hearing loss (SSHL) is defined as a sensorineural hearing loss with at least 30-dB decrease in threshold in three contiguous t e s t f requencies occurring over a 24 to 72-hour per i o d 1 . This condition is usually unilateral and may be comp l e t e 2 . Many diff e rent causes of SSHL have been hypothesized, such as viral infection of the lab y r i n t h or cochlear nerve, vascular insult, perilymphatic h ypoxia, intralabyrinthine membrane ru p t u re, inflamm a t o ry and metabolic causes, immune-mediated i nner ear disease, perilymphatic fistulas and others 3 , 4 . Viral infection is the most common pre s u m e d cause of SSHL 2 -5 . Nearly one-third of the patients w ith SSHL has abnormal MRI findings, generally labyrinth or internal auditory alterations 4,6 . However, isolated white matter signal alteration at the MRI was not previously re p o rted in patients with SSHL.We present two pediatric patients with SSHL w h o had at the brain MRI diffuse alteration of the white matter signal. CASEThe study was approved by the ethical committee of our hospital and the parents signed informed consent. ABSTRACT -Objective: To describe the MRI findings of two pediatric patients with sudden sensorineural hearing loss (SSHL). Case reports: Two male patients (two-year and three-months-old, and one year and f o u r-months-old) presented with sudden dumbness. Physical and neurological examinations were unre m a rkable besides bilateral hypoacusia. All the laboratory investigation was negative, and brain stem auditory evoked potentials showed deep bilateral deafness in both cases. MRI studies revealed normal inner ears and multifocal white matter areas of slight low signal on T1-weighted images and high signal on FLAIR images. The follow-up MRI studies and neurological examinations did not demonstrate alterations in the p revious findings. Conclusion: Pediatric patients with SSHL may present cerebral white matter signal a b n o rmalities at the MRI as the only finding. Further studies with larger casuistics need to be conducted to elucidate these findings. UNUSUAL MAGNETIC RESONANCE FINDINGS IN TWO CHILDREN WITH SUDDEN SENSORINEURAL HEARING LOSSKEY WORDS: magnetic resonance imaging, sudden sensorineural hearing loss, cerebral white matter.Achados incomuns nas ressonâncias magnéticas de duas crianças com perda auditiva neuro -s e nsorial súbita RESUMO -Objetivo: D e s c rever os achados de ressonância magnética (RM) em dois pacientes pediátricos com perda auditiva neuro-sensorial súbita (PA N S ) . Relato dos casos: Dois pacientes masculinos (dois anos e três meses e um ano e quarto meses de idade) apresentaram-se com surdez súbita. Os exames físico e n e u rológico foram normais, à exceção da hipoacusia. Toda a investigação laboratorial foi normal, e os potenciais auditivos evocados do tronco cerebral demonstraram surdez profunda bilateral. Os exames de RM evidenciaram estruturas normais dos ouvidos internos e áreas multifocais de discreto hipossinal em T1 e hipersinal em FLAIR na substância bran...