Magnetic resonance imaging findings in children with spasmus nutans

Abstract

To the Editor: I read with interest the article by Bowen and colleagues1Bowen M. Peragallo J.H. Kralik S.F. Poretti A. Huisman T.A.G.M. Soares B.P. Magnetic resonance imaging findings in children with spasmus nutans.J AAPOS. 2017; 21: 127-130Abstract Full Text Full Text PDF PubMed Scopus (8) Google Scholar regarding magnetic imaging findings in children with spasmus nutans. The authors correctly mention that spasmus nutans may mimic underlying retinal pathology. I would like to highlight that there is one retinopathy in particular that tends to be mistaken as spasmus nutans in children—“cone dystrophy with supranormal rod response” (KCNV2-related retinopathy).2Khan A.O. Alrashed M. Alkuraya F.S. “Cone dystrophy with supranormal rod response” in children.Br J Ophthalmol. 2012; 96: 422-426Crossref PubMed Scopus (30) Google Scholar This form of retinal dystrophy, one of the few with a pathognomonic electroretinogram, seems more common on the Arabian Peninsula and, in my experience, is the most common cause of a spasmus nutans–like picture in the region.3Khan A.O. Recognizing the KCNV2-related retinal phenotype.Ophthalmology. 2013; 120: e79-e80Abstract Full Text Full Text PDF PubMed Scopus (7) Google Scholar Affected children can present in infancy with intermittent small-amplitude high-frequency variable nystagmus, torticollis, head shaking, and a normal appearing fundus—characteristics common to spasmus nutans. With time, these findings tend to resolve, as is also characteristic for spasmus nutans. This highlights the fact that retinal disease needs to be ruled out before making a final diagnosis of spasmus nutans. Magnetic resonance imaging findings in children with spasmus nutansJournal of American Association for Pediatric Ophthalmology and Strabismus {JAAPOS}Vol. 21Issue 2PreviewSpasmus nutans (SN) is a rare pediatric ophthalmologic syndrome characterized by nystagmus, head bobbing, and abnormal head positioning. Historically, SN has been associated with underlying optic pathway gliomas (OPG); however, evidence of this association is based primarily on a small number of isolated case reports. Prior retrospective analyses have found the rate of OPG to be <2%, but these studies only intermittently used neuroimaging with computed tomography, which has limited sensitivity for detection of small lesions in the optic pathway. Full-Text PDF ReplyJournal of American Association for Pediatric Ophthalmology and Strabismus {JAAPOS}Vol. 21Issue 4PreviewWe appreciate the comment by Khan on Bowen and colleagues1 and the insight into an unusual form of nystagmus2 that can be mistaken for spasmus nutans. The particular entity described by Khan is due to KCNV2-related retinopathy.2,3 Several entities can mimic spasmus nutans and may be termed spasmus nutans–like. The findings upon presentation of these children with KCNV2-related retinopathy (intermittent small-amplitude, high-frequency variable nystagmus with torticollis and head shaking) are very similar to spasmus nutans, and distinguishing the two entities without an electroretinogram would be extremely difficult. Full-Text PDF