Dystonia, a movement disorder characterized by excessive muscle contractions that can be sustained or intermittent, is often misdiagnosed by physicians as essential tremor (ET), particularly when tremor is present. In one study, 8% of patients with an intake diagnosis of “ET” were found to have isolated dystonia rather than ET.1 Here, we present an educational video of a 77-year-old patient enrolled in an ET study at Yale University. Our aim is to aid physicians in the recognition of cervical dystonia. The intention of the ET study was to enroll ET patients who had no additional neurological diagnoses such as dystonia. As part of our patient’s screening questionnaire, she reported having been diagnosed with ET and denied ever being diagnosed with dystonia. She had developed upper limb tremor as a young adult, which had gradually worsened. In addition, she noted onset of head tremor in her mid-60s. She had an extensive family history of ET, with multiple affected first- and second-degree relatives. There was no family history of dystonia. Over the years, she had been under the care of a primary care physician and two neurologists who had attributed her upper limb and head tremors to ET. On our neurological examination, there was moderate postural tremor, moderate-to-severe kinetic tremor, and an occasional intention tremor of her upper extremities (Videos 1–5), confirming her ET diagnosis. In addition, she had each of the following significant features of cervical dystonia: (1) head tremor that was somewhat irregular (Videos 5 and 6), (2) head tremor that had a directional quality (Videos 5 and 6), (3) neck turning (left laterocollis) (Video 6), which was even acknowledged by the patient (Videos 8 and 9), (4) a null point – lessening of the head tremor when she turned her head to the left (Videos 8 and 9), (5) hypertrophy of the right sternocleidomastoid muscle (Video 6), (6) cervical discomfort (Videos 8 and 9), and (7) the persistence of neck tremor while supine (Video 10).2 There were also a few signs of subtle limb dystonia (Videos 2 and 7). Our patient displayed long-standing, typical, familial ET, with co-occurring dystonia on examination. The concomitant presence of dystonic movements/postures in some ET patients is increasingly being recognized,3 although there is debate as to when the presence of dystonia on examination necessitates an additional diagnosis (i.e., a second diagnosis of dystonia). Regardless, physical examination findings of dystonia are often underrecognized or are attributed to ET, which can lead to errors in clinical research and treatment. Recognition of these physical examination findings, along with the use of other methods to identify dystonia (e.g., electromyography to test for the presence of abnormal patterns of neck muscle activation), may reduce such errors.
1 Citation: Hale EA, Liu G, Kim CY, Louis ED. Under-Recognition of Cervical Dystonia: An Essential Tremor Patient with Numerous Textbook Features of Cervical Dystonia. Tremor Other Hyperkinet Mov. 2019; 9. doi: 10.7916/tohm.v0.733
2 Editor: Julian Benito-Leon, Hospital “12 de Octubre,” Spain
3 Funding: This research was supported by the National Institutes of Health Grant R01 NS094607.
4 Financial Disclosures: None.
5 Conflicts of Interest: The authors report no conflicts of interest.
6 Ethics Statement: This study was performed in accordance with the ethical standards detailed in the Declaration of Helsinki. The authors’ institutional ethics committee has approved this study and all patients have provided written informed consent. All patients who appear on video have provided written informed consent; authorization for the videotaping and for publication of the videotape was provided.
Jain, S, , Lo, SE , Louis, ED, Common misdiagnosis of a common neurological disorder: how are we misdiagnosing essential tremor? Arch Neurol 2006;63:1100–1104. doi: https://doi.org/10.1001/archneur.63.8.110016908735
Louis, ED Essential tremor: a nuanced approach to the clinical features. Pract Neurol 2019;19(5):389–398. doi: https://doi.org/10.1136/practneurol-2018-00218331273079
Bhatia, KP , Bain, P , Bajaj, N , Elble, RJ , Hallett, M , Louis, ED , et al. Consensus statement on the classification of tremors from the task force on tremor of the International Parkinson and Movement Disorder Society. Mov Disord 2018;33:75–87. doi: https://doi.org/10.1002/mds.2712129193359