Subacute Onset of “Chorea” with Cervical Dystonia

A 32-year-old man, with congenital deafness communicating with sign language or in writing, presented for assessment of new onset involuntary movements for 1 month. He had neck pain and head turn to the left, which progressed to involve flailing-movements of both arms and with frequent spontaneous repetitive flexion of his body, leading to falls. There was no family history of similar movements or known exposure to dopamine blocking agents. He was hospitalized for complex hyperkinetic movements that were initially felt to be "chorea", and some functional overlay as his movements were believed to be distractable. Blood and CSF workup, including Antistreptolysin-O Antibody(Ab), IgLON5 Abs, Anti-Paraneoplastic Abs, encephalitis Abs and urine organic acids, were negative. However, he had a positive PCR for COVID-19 on a nasopharyngeal swab, although he was asymptomatic for this. Brain MRI showed nonspecific periventricular white matter changes of both atria and posterior horns (Fig. 1). When examined by the movement disorder team, he was found to have generalized dystonia. Dystonic posturing of the head, with stereotyped repetitive head forward shift, left tilt and turn. He had stereotyped flexion movements of both upper extremities and trunk at rest and when walking. Only when lying in bed, he tended to invert his feet when activating his upper extremities. He had writer dystonia in the right hand with some mirroring on the left hand (Video 1). His eye movements, cerebellar exam and gait were normal. Further history revealed that the patient had difficulty writing in school and slight abnormal posturing of the head for many years, but both issues were never significant. Cyclobenzaprine, lorazepam, and levodopa were ineffective. He was discharged on Trihexyphenidyl 9 mg per day and symptoms resolved almost completely within 1 month of continued treatment. Genetic testing revealed a pathogenic ACTB gene mutation, on exon 4 (c.547C > T, p.Arg183Trp), causing Deafness dystonia syndrome (DDS). DDS is a rare syndrome, with other genetic causes, including Mohr-Tranebjaerg syndrome (TIMM8A gene) and Baraitser-Winter Cerebrofrontofacial syndrome (BWCFF) in addition to idiopathic and metabolic causes (organic acidurias and mitochondrial diseases).1 Adult onset generalized dystonia cases are rare and often misdiagnosed due to the large variation in movement amplitude, especially when truncal involvement and an atypical gait are present, which can be mistaken for functional symptoms. Deafness is an uncommon association with dystonia.2 In this case, the dystonic symptoms developed insidiously earlier in his life, allowing the patient to maintain full-time employment and independent living. The precise trigger for the dystonic storm remains unclear, but an underlying COVID-19 infection around the time of symptom onset could have exacerbated the patient's dystonia, knowing that COVID-19 was reported to cause dystonia in only one case.3 Importantly, the dystonic symptoms were responsive to high dose trihexyphenidyl, unlike most published cases which were refractory to oral treatment.1, 4 In addition, there is growing evidence of dystonia responsiveness to bilateral GPi stimulation, with five cases being reported in the literature.4, 5 Finally, delayed recognition of early dystonic symptoms, especially in patients with communication disabilities, can lead to unnecessary investigations and treatment delays. J.S.: 1C, 3A. D.G.: 1A, 3B. Ethical Compliance Statement: This clinical vignette doesn't require any ethical committee approval. Oral consent was taken from the patient to video record his symptoms and report his case. We confirm that we have read the Journal's position on issues involved in ethical publication and affirm that this work is consistent with those guidelines. Funding Sources and Conflict of Interest: No specific funding was received for this work. The authors declare that there are no conflicts of interest relevant to this work. Financial Disclosures for the previous 12 months: JS declares that there are no additional disclosures to report. DG: Honorarium for speaking from Ipsen. Honorarium for consulting from Abbvie. Funding for clinical trials from CIHR, Cerevel Therapeutics, Hoffman-La Roche, UCB Biopharma and Bial R&D Investments. Research grants from CIHR, Parkinson Canada, Brain Canada, Parkinson Research Consortium, EU Joint Program—Neurodegenerative Disease Research, uOBMRI and NIH.