Session Information
Date: Thursday, June 23, 2016
Session Title: Other
Session Time: 12:00pm-1:30pm
Location: Exhibit Hall located in Hall B, Level 2
Objective: We aimed to determine the sensitivity and specificity of the “whack-a-mole” sign in our movement disorders clinic population.
Background: The “whack-a-mole” sign, characterized as immediate reemergence or worsening of movement in another body part followed by suppression of a moving body part has been previously described in functional movement disorder (FMD) patients.
Methods: We prospectively tested for the “whack-a-mole” sign in patients who presented to our movement disorders clinic from March of 2015 through December of 2015. 114 patients presented during this period, of which 47 patients had involuntary movements that were observed on the day of the visit. 22 patients diagnosed with FMD, 22 patients diagnosed with an organic movement disorder and 3 patients diagnosed with an organic movement disorder with functional overlay were tested for the “whack-a-mole” sign (mean age 53.3 years, standard error 2.6 years). Patients were examined and also questioned about self-suppressibility of movements, worsening or appearance of movement in another body part upon suppression, and if this phenomenon was present in their daily lives.
Results: A total of 9 patients tested positive for the “whack-a-mole” sign (mean age 41.3, standard error 5.8 years, disease duration 6.4 years and standard error 2.2 years). 7 out of 9 patients were patients diagnosed as FMD or having a functional overlay, resulting in a 28% sensitivity of a positive “whack-a-mole” sign (7 out of 25 FMD and patients with overlay). Five of these patients reported self-suppressibility and of these, 4 noted experiencing a “whack-a-mole” phenomenon in their daily lives.
Conclusions: The “whack-a-mole” sign is a clinical feature seen mostly in FMD (positive predictive value of 78%), with a sensitivity of 28% and specificity of 91%. We propose that this sign may be useful to test for in this patient population, as the high specificity and the low-to-moderate sensitivity may help the physician to consider FMD or a functional component when this phenomenon is seen.
To cite this abstract in AMA style:
J.E. Park, C. Maurer, M. Villegas, M. Hallett. Testing for the “whack-a-mole” sign in the movement disorders clinic [abstract]. Mov Disord. 2016; 31 (suppl 2). https://www.mdsabstracts.org/abstract/testing-for-the-whack-a-mole-sign-in-the-movement-disorders-clinic/. Accessed June 15, 2025.« Back to 2016 International Congress
MDS Abstracts - https://www.mdsabstracts.org/abstract/testing-for-the-whack-a-mole-sign-in-the-movement-disorders-clinic/