Hypsarhythmia was originally spelled with one ‘r’ by Drs Frederick and Erna Gibbs when they coined the term in 1952 [1]. They wished to emphasize that “the term applied to a specific type of electroencephalographic abnormality”, and preferred the specific one ‘r’ spelling to avoid confusion with a literal translation of the two ‘r’ Greek root, “mountainous arrhythmia” [2, 3]. The one ‘r’ spelling was the rule in the 1950s-60s [4]. The two ‘r’ spelling eventually became convention in the literature by the mid-1970s (Figure 1).

Figure 1 

Google Ngram Viewer: Book text search for case-insensitive ‘Hypsarrhythmia’ (blue line) and ‘Hypsarhythmia’ (red line) from 1950-2008 in English. [Cited August 31 2015.] Available from: https://goo.gl/sJI1uG

Although the Editor of Pediatric Neurology Briefs prefers the single ‘r’ spelling in deference to Dr Gibbs, the intended meaning is accepted for both spellings today.