Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2023 Apr 1:8:100196.
doi: 10.1016/j.prdoa.2023.100196. eCollection 2023.

Plantar Grasp sign as a screening tool for Orthostatic Tremor (OT)

Rebecca Thompson  1   2 , Danish Bhatti  1 , Kalyan Malgireddy  1 , Venkata Sunil Bendi  1 , John M Bertoni  1 , Vekash Raja  1 , Diego Torres-Russotto  1
Affiliations

Plantar Grasp sign as a screening tool for Orthostatic Tremor (OT)

Rebecca Thompson et al. Clin Park Relat Disord. .

Abstract

Introduction: Orthostatic tremor (OT) is a rare neurological disorder characterized by a sensation of instability while standing. Very few clinical signs have been described for OT to date. Finding other symptoms and signs could prove valuable for this hard-to-recognized disease.

Methods: This protocol is part of the University of Nebraska Medical Center Orthostatic Tremor longitudinal study. It was noted that OT patients flex their toes and sometimes the foot arch while standing (Plantar Grasp). They reported doing this to "grab" the floor and improve stability. This paper analyses the diagnostic test characteristics of the patient-self-reported Plantar Grasp, a new sign in OT.

Results: There were 34 OT patients (88% females), and 20 controls (65% females). Eighty-eight percent of patients with OT reported the plantar grasp sign and none of the controls. The Plantar Grasp Sign was found to be very sensitive (88%), and extremely specific (100%) in our cohort. Non-weighted Negative Likelihood Ratio (NLR) was 0.12. And the 3% prevalence-weighted NLR was so low that the negative post-test probability was close to zero.

Conclusion: Due to its high sensitivity, specificity, and ideal likelihood ratio, we propose that the Plantar Grasp sign could be considered to screen patients with possible OT. Further studies are needed to determine the specificity of this sign in OT versus other balance disorders.

Keywords: Orthostatic tremor; Plantar Grasp sign; Screening tool; Sensitivity and specificity.

PubMed Disclaimer

Conflict of interest statement

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Figures

Fig. 1
Fig. 1
Orthostatic Tremor patient while sitting and standing. A) Normal posture of the feet when sitting B) Plantar Grasp sign: Flexion of toes and the plantar arch while standing.
See this image and copyright information in PMC

References

    1. Bhatia K.P., Bain P., Bajaj N., Elble R.J., Hallett M., Louis E.D., Raethjen J., Stamelou M., Testa C.M., Deuschl G. Consensus Statement on the classification of tremors. from the task force on tremor of the International Parkinson and Movement Disorder Society. Mov. Disord. 2018;33(1):75–87. - PMC - PubMed
    1. Yaltho T.C., Ondo W.G. Orthostatic tremor: a review of 45 cases. Parkinsonism Relat. Disord. 2014;20:723–725. doi: 10.1016/j.parkreldis.2014.03.013. - DOI - PubMed
    1. Hassan A., Ahlskog J.E., Matsumoto J.Y., Milber J.M., Bower J.H., Wilkinson J.R. Orthostatic tremor: Clinical, electrophysiologic, and treatment findings in 184 patients. Neurology. 2016;86:458–464. doi: 10.1212/WNL.0000000000002328. - DOI - PubMed
    1. Bhatti D., Thompson R., Xia Y., Hellman A., Schmaderer L., Suing K., McKune J., Penke C., Iske R., Roeder B.J., Situ K.C., Bertoni J.M., Torres-Russotto D. Comprehensive, blinded assessment of balance in orthostatic tremor. Parkinsonism Relat. Disord. 2018;47:22–25. doi: 10.1016/j.parkreldis.2017.11.335. - DOI - PubMed
    1. Erro R., Antelmi E., Bhatia K.P. A disorder which occurs on standing: The Earliest Account of Orthostatic Tremor by Pazzaglia. Mov. Disord. Clin. Pract. 2015;2(1):39–40. - PMC - PubMed

LinkOut - more resources