CNS Imaging is Essential in Acquired Bilateral Vocal Fold Dysfunction in Children

Abstract

Dear Sir,

I greatly enjoyed reading the paper by David and Lim on “Congenital Bilateral Vocal Fold Paralysis”¹ and complement the authors on their excellent surgical outcome.  They also very appropriately underscored the primacy of careful clinical assessment over costly investigations, particularly in an environment of scarce resources.

We have previously reported on the MRI findings in 23 children with bilateral vocal fold dysfunction (BVFD) as an isolated abnormality that was present at birth.  We found MRI abnormalities in 35%, but these were all non-specific.² This study indicated that MRI was of research and clinical value, but did not identify any major CNS structural abnormalities in this patient group.

However, the case reported by David and Lim involved the delayed onset of symptoms at 2 years of age that may have increased over the next 3 years.  This acquired and possibly progressive disease process differs from that of congenital BVFD.  The likelihood of Arnold-Chiari malformation or another significant structural CNS abnormality being present would appear to be higher when symptoms of BVFD are acquired later in life compared to when they are present at birth.

Anecdotally, I have been involved with a case of acquired BVFD presenting at a similar age where the underlying cause was found to be a posterior fossa tumour.  The 3 year history of symptoms in the child in the case report would very likely preclude this diagnosis, but certainly another CNS cause needs to be considered to explain the development of delayed-onset brainstem dysfunction, and this would require MRI.

Robert Berkowitz

Department of Otolaryngology

Royal Children’s Hospital

Melbourne, Australia