Objective: To recall some clinical situations and causes of dystonic tremor (DT).
Background: DT is a tremor produced by dystonic muscle contraction. It is an underdiagnosed entity, especially when subtle, and it can be the clinical presentation of various etiologies.
Method: We conducted an observational study on patients who presented to our neurology department for management of DT.
Results: We collected three patients, one woman and two men, with a median age of 48 years old. They all complained of an abnormal posture with involuntary shaking in different parts of the body. The female patient was followed in our department for management of multiple sclerosis (MS). She developed a DT of her right thumb that was intermittent, lasted less than 24 hours, but reoccurred every day during two months. The electroencephalogram (EEG) with a needle electrode was normal. A cerebral and spinal cord magnetic resonance imaging (MRI) showed hyperintensities in the periventricular and subcortical region, the corpus callosum, the medulla oblongata and the cervical spinal cord at the level of C2-C3 and C5-C6. The latter localization of demyelination was at the origin of the movement disorder, as part of paroxysmal symptoms of MS. The patient received intravenous corticosteroids and oral uptake of carbamazepine with full recovery. The first male patient complained of DT that had started at the age of 18 years old in the left lower limb to than affect the left upper limb after 7 years. He was born from a consanguineous marriage and had similar cases in the family (maternal aunt, paternal uncle). Upon examination, the DT worsened when walking, was relieved by supine position, and was insensitive to levodopa. His cerebral MRI was normal. The second male patient reported a paroxysmal cervical DT at the age of 63 years old. Cerebral MRI showed high signal of the periventricular area with no signal abnormality in the basal ganglia and the EEG was normal. Levodopa Test was positive. For these two patients, screening for infectious, metabolic and autoimmune disorders as well toxicology tests came back negative. Therefore, a hereditary cause was suspected and a genetic testing was performed.
Conclusion: DT is an infrequent reason of consultation. It can be a clinical manifestation of inflammatory diseases, such as MS, attesting of a relapse or its sequela. A genetic cause should be suspected, even for the elderly, especially with the presence of a family history.
To cite this abstract in AMA style:
S. Laroussi, S. Sakka, N. Bouattour, N. Farhat, S. Daoud, K. Moalla, H. Hadjkacem, M. Damak, C. Mhiri. Dystonic tremor: one symptom, different etiologies: About three cases [abstract]. Mov Disord. 2022; 37 (suppl 2). https://www.mdsabstracts.org/abstract/dystonic-tremor-one-symptom-different-etiologies-about-three-cases/. Accessed September 7, 2024.« Back to 2022 International Congress
MDS Abstracts - https://www.mdsabstracts.org/abstract/dystonic-tremor-one-symptom-different-etiologies-about-three-cases/