|LETTER TO THE EDITOR
|Year : 2022 | Volume
| Issue : 1 | Page : 77-78
Spiral drawing in myoclonus
Harsh V Gupta1, Rajinder K Dhamija2
1 Department of Neurology, Mayo Clinic, Jacksonville, FL, USA
2 Department of Neurology, Lady Hardinge Medical College, New Delhi, India
|Date of Submission||20-Jul-2021|
|Date of Decision||30-Sep-2021|
|Date of Acceptance||15-Oct-2021|
|Date of Web Publication||06-Jan-2022|
Dr. Harsh V Gupta
Mayo Clinic, Jacksonville, FL
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Gupta HV, Dhamija RK. Spiral drawing in myoclonus. Ann Mov Disord 2022;5:77-8
Myoclonus is a movement disorder characterized by sudden, brief, and involuntary movements that can affect any body part. Myoclonus mimics tremor when it involves the muscles of distal upper extremities, giving an appearance of tremulousness. Multichannel surface electromyography (EMG) along with electroencephalography (EEG) back averaging aid in the diagnosis of myoclonus, but it is available only at specialized centers. It is imperative to distinguish between tremor and myoclonus because appropriate management depends on the accuracy of the diagnosis.
Spiral drawing is a useful tremor evaluation tool as it can aid in distinguishing between Parkinson’s disease, essential tremor, dystonic tremor, and psychogenic tremor. The best reliability of the spiral drawing is observed when the hand is unsupported and the spirals are drawn without tracing a previously drawn spiral (freehand). In this observational study, we evaluated the spiral drawings of five patients with myoclonus ([Table 1]). The diagnosis of myoclonus was based solely on clinical examination. The spiral drawing pattern of the patients with myoclonus showed irregular spikes ( [Figure 1], Video 1). The most likely explanation of the irregular spikes is the brief and sudden nature of myoclonus. The spiral drawing of patients with essential tremor usually has a saw tooth or semioval appearance ([Figure 1]).
|Figure 1: Spiral drawing in a patient with myoclonus shows spikes highlighted by blue arrows. (A) Horizontal line drawing demonstrates spikes due to interruption by myoclonus. (B) Spiral drawings of two different patients with essential tremor show predominant unidirectional axis (left side) (C) and saw-tooth appearance (right side) (D) due to tremor|
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[Additional file 1]
Despite our promising findings, our study has some limitations. Our sample size was small, and our study lacks a multichannel surface EMG recording. The appearance of spikes on a spiral drawing needs to be studied in a large number of patients with electrophysiologically confirmed myoclonus. Spiral drawing is a potentially useful tool in the evaluation and differentiation of myoclonus from tremor.
1) Research project: A, conception; B, organization; C, execution
2) Manuscript: A, writing of the first draft; B, review and critique
HVG: 1A, 1B, 1C, 2A, 2B
RKD: 1B, 2A, 2B
We have read the Journal’s position on issues involving ethical publication and affirm that this report is consistent with those guidelines. All authors have approved the final article.
The authors certify that they have obtained all appropriate patient consent forms. Written informed consent was provided by the patient for his images, video, and other clinical information to be reported in the journal. The patient understands that his name and initials will not be published and due efforts will be made to conceal his identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest to declare.
| References|| |
Caviness JN, Brown P Myoclonus: Current concepts and recent advances. Lancet Neurol 2004;3:598-607.
McKeon A, Pittock SJ, Glass GA, Josephs KA, Bower JH, Lennon VA, et al
. Whole-body tremulousness: Isolated generalized polymyoclonus. Arch Neurol 2007;64:1318-22.
Alty J, Cosgrove J, Thorpe D, Kempster P How to use pen and paper tasks to aid tremor diagnosis in the clinic. Pract Neurol 2017;17:456-63.
Ondo WG, Wang A, Thomas M, Vuong KD Evaluating factors that can influence spirography ratings in patients with essential tremor. Parkinsonism Relat Disord 2005;11:45-8.