Objective: To evaluate the appropriateness of the 1990 change in nomenclature from palatal myoclonus to palatal tremor, and the acceptance rate of the change in subsequent publications.

Background: Movement disorder nomenclature undergoes changes over time for varied reasons.
In 1990, a group of movement disorders specialists attending a video presentation decided to change the name of the disorder known as “palatal myoclonus” to “palatal tremor”.
There are only 2 criteria a movement disorder must meet to be classified as a tremor: it must be rhythmic and osciallatory.

Method: Literature published before and after the 1990 change was reviewed for evidence supporting or refuting the classification of this disorder as either myoclonus or tremor. PubMed was searched with “palatal AND myoclonus” and “palatal AND tremor”. Discarding duplicates, the frequency of utilization of the terms “palatal myoclonus” and “palatal tremor” was recorded.

Results: In the last two decades, an approximately 2:1 majority of publications have preferred the term “palatal tremor”, although in 2018-19, there was a slim majority of articles preferring “palatal myoclonus”. Rhythmicity can be judged in these publications by reviewing videos or electrophysiologic data. Even when using the term “palatal tremor”, videos accompanying publications invariably show arrhythmic palatal movements, and EMG recordings document arrhythmic contraction intervals. Review of the anatomy of palatal musculature demonstrates no.true antagonist muscles to tensor veli palatini and levator veli palatine; thus no oscillation of the palate is possible.

Conclusion: This disorder fulfills neither of the criteria necessary for tremor: it is arrhythmic, and it is anatomically impossible for the palate to oscillate. In a giant nose-thumbing at evidence-based medicine, however, a select group of movement disorders specialists voted “by a show of hands” to change the name of “palatal myoclonus” to “palatal tremor” after reviewing a single video. On the basis of much of the evidence presented here, it was decided “by a show of hands” at the 2012 AAN Unusual Movement Disorders session to change the name back to “palatal myoclonus”.

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MDS Abstracts - https://www.mdsabstracts.org/abstract/nomencladventure-palatal-myoclonus-and-palatal-tremor/