The Shaking Shoelace

Bastiaan R. Bloem*, Rick C. Helmich, Tiane Tilanus, Bart P. van de Warrenburg

Radboud University Medical Centre, Donders Institute for Brain, Cognition and Behaviour, Department of Neurology, Nijmegen, The Netherlands

View video that accompanies this article here: Supplementary Video (opens in new screen)

It is good practice to physically examine patients while being undressed. Here, we illustrate that observation of clothes in dressed patients can occasionally also yield valuable information.

A 59-year-old man with Parkinson’s reported a subjective tremor. Yet, neurological examination showed no tremor while observing the bare extremities (video section A; showing no discernible tremor in the bare feet).

However, while wearing shoes, a subtle tremor was revealed by rhythmic oscillations of the left shoelace (video section B), which presumably acted as a lever, much like the mechanisms used for earthquake detection.

Power spectrum analysis of the video showed no discernible tremor in the bare feet, but examination of the oscillations of the left shoelace revealed a distinct tremor (peak frequency of 3.45  Hz) compatible with Parkinson’s disease (video section C).

This underscores that observing patients while still dressed may occasionally be needed to bring out the full repertoire of key physical signs.

Caption: Screenshots of accompanying video: top left = video section A; top right = video section B; bottom center = video section C

CONFLICT OF INTEREST

BRB, RH, and BvdW report no disclosures.

AUTHOR CONTRIBUTIONS
BB and TT: collecting video data and drafting the manuscript.

RH: expert opinion and revising the manuscript.

BvdW: arranging tremor quantification and revising the manuscript.

ACKNOWLEDGMENTS
We thank Radim Krupička and Evžen Růžička for analysis of the tremor.

______

Full citation:

The Shaking Shoelace, by Bastiaan R. Bloem, Rick C. Helmich, Tiane Tilanus, and Bart P. van de Warrenburg, J Parkinsons Dis, 9:1, 249–250, 2019 (DOI 10.3233/JPD-181541).

1