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Severe closed-mouth oromandibular dystonia secondary to stroke
*Corresponding author: Weisheng Zhuang, Department of Rehabilitation, Henan Provincial People’s Hospital, Zhengzhou, China. zhuang20062634@163.com
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Received: ,
Accepted: ,
How to cite this article: Wang Y, Wang X, Lei B, Zhuang W. Severe closed-mouth oromandibular dystonia secondary to stroke. J Neurosci Rural Pract. 2026;17:322-5. doi: 10.25259/JNRP_378_2025
Abstract
This case report describes a 68-year-old female patient with secondary closed-mouth oromandibular dystonia (OMD) following intracerebral hemorrhage, presenting with severe trismus that significantly impairs eating and speech. The patient underwent precise Botulinum Toxin Type A (BoNT-A) injection guided by ultrasound and electromyography. Systematic temporomandibular joint (TMJ) manual rehabilitation therapy commenced the following day and was administered 5 sessions per week for three weeks. Mouth opening degree and Modified Barthel Index (MBI) were assessed at baseline, 1 week post-treatment, 2 weeks post-treatment, 6 weeks post-treatment, and at the 2-month follow-up. Following treatment, the patient’s mouth opening degree increased from 0 mm to 36 mm, and the MBI score improved from 35 to 65. The patient resumed oral feeding, with significantly enhanced speech function. At the 2-month follow-up, therapeutic efficacy remained stable with no adverse reactions observed. Ultrasound- and electromyography-guided precise BoNT-A injection combined with TMJ manual rehabilitation represents an effective treatment strategy for this patient, significantly improving their mouth opening function and quality of life.
Keywords
Botulinum toxin type A
Oromandibular dystonia
Rehabilitation therapy
Stroke
INTRODUCTION
Oromandibular dystonia (OMD) is a focal dystonia characterized by involuntary contractions of the mandibular, lingual, and facial muscles.[1] It predominantly affects middle-aged and elderly females, among whom the closed-mouth type of OMD is the most common, presenting with trismus and severe difficulty in opening the mouth, and significantly impairing patients’ ability to eat, speak, and perform other daily functions.[2,3] OMD prevalence is 68.9 cases per million population.[4] Based on etiological factors, OMD is divided into primary and secondary types. Secondary OMD accounts for only a small proportion.[5] Therefore, OMD cases induced by stroke as one of the secondary causes are prone to misdiagnosis or underdiagnosis.[6,7] The treatment of dystonia should be tailored to individualized conditions. Botulinum toxin injection is the first-line therapy for focal and segmental types, including OMD; pharmacotherapy or deep brain stimulation is the mainstay for the generalized type.[8] However, botulinum toxin’s primary effect lies in alleviating dystonia, and it has limited efficacy in addressing mechanical dysfunctions such as temporomandibular joint (TMJ) stiffness and soft-tissue contracture caused by long-term muscle hypertonia. Therefore, combining BoNT injection with targeted manual rehabilitation holds promise for exerting a synergistic effect at both the neural inhibition and mechanical improvement levels, thereby further enhancing therapeutic efficacy. This study explores the clinical efficacy of ultrasound- and electromyography (EMG)-guided botulinum toxin type A (BoNT-A) injection combined with TMJ manual rehabilitation therapy in a case of post-stroke closed-mouth OMD, to provide a reference for the comprehensive diagnosis and treatment of such patients.
CASE REPORT
A 68-year-old female patient was presented to the clinic with “progressive difficulty in opening the mouth accompanied by dysphagia and dysarthria for more than 2 months.” Three years ago, the patient was diagnosed with “cerebral hemorrhage” due to the sudden onset of the left limb weakness, and underwent “decompressive craniectomy with hematoma evacuation.” Postoperatively, her condition was stable, with residual mild left hemiplegia. After rehabilitation treatment, she was able to eat independently without dysphagia or dysarthria. More than 2 months ago, the patient developed limited mouth opening, which progressively worsened to complete inability to open the mouth, accompanied by dysarthria. She now relies on a nasogastric tube for feeding. She has a medical history of hypertension for 5 years, has been taking medication regularly, and her blood pressure is well-controlled.
Specialized physical examination
Conscious and alert, but lethargic, with dysarthria. The patient exhibits severe limitation of mouth opening movement. In the supine position, the vertical incisal edge distance between the maxillary and mandibular incisors is 0 mm. The Kubota Drinking Test and X-ray swallowing fluoroscopy study could not be performed due to severe limitations of mouth opening. The patient had normal muscle tone in the limbs and trunk, with a modified Ashworth Scale score of 0. The modified Barthel index (MBI) score was 35 points.
Imaging studies
Head magnetic resonance imaging revealed post-operative encephalomalacia lesions with hemosiderin deposition in the right frontal, temporal, and insular lobes, microhemorrhages in the left basal ganglia region and left parietal lobe, multiple lacunar infarcts in the left temporal lobe, periventricular area, and left basal ganglia region, as well as Wallerian degeneration and cerebral atrophy [Figure 1].
Musculoskeletal ultrasound combined with EMG
It revealed the presence of abnormal spontaneous electrical activity in the left masseter, left temporalis, and left medial pterygoid muscle at rest.
Intervention and Outcomes
The patient and their family members signed the informed consent form, agreeing to undergo combination therapy and consenting to the publication of this study.
Treatment measures: Based on the patient’s diagnosis and assessment results, the following comprehensive treatment plan is formulated:
BoNT-A injection: BoNT-A (trade name: Botox®,Allergan, Inc., USA) was used. After ultrasound was employed to locate the boundaries of the muscle groups and EMG confirmed the areas of abnormal electrical activity, an experienced physician administered precise injections to the left masseter muscle (30 U), left temporalis muscle (30 U), and left medial pterygoid muscle (40 U), with a total dose of 100 U.
TMJ manual rehabilitation therapy: It was initiated 24 h after BoNT-A injection, administered by a full-time physical therapist, with each session lasting 30 min, 5 sessions per week, for a total of 3 weeks.
Specifically, it includes:
Muscle relaxation training: The patient assumes the supine position, and the therapist gently massages the bilateral temporalis muscles, masseter muscles, medial pterygoid muscles, and infrahyoid muscles, with each massage lasting approximately 2 min.
Joint mobilization training: The therapist, wearing sterile gloves, applies traction to the mandible in an anterior– inferior direction, holding the position at the end of the traction for 5 s, and alternates between the two sides; the therapist instructs the patient to actively perform mandibular protrusion and mouth closure movements, ensuring midline alignment.
Articular disc repositioning manipulation: The therapist places their thumbs on the patient’s molar region, while the remaining four fingers stabilize the mandibular ramus; they apply traction in an anterior– inferior direction and instruct the patient to attempt active mouth opening simultaneously, maintaining the manipulation for a total duration of 2 min.
Outcome assessment: In this study, the interincisal distance between the maxillary and mandibular incisors (viz., mouth opening, also referred to as opening amplitude; unit: Millimeters [mm]) was employed as the primary outcome measure, supplemented by the MBI. Measurements were taken at baseline, 1 week post-treatment, 2 weeks post-treatment, and 6 weeks post-treatment, with a follow-up visit conducted 2 months after treatment completion. Before treatment, the patient exhibited abnormally restricted mouth opening, with an MBI score of 35. One week post-treatment, the patient’s mouth opening showed initial improvement to 5 mm; at 2 weeks post-treatment, it significantly increased to 20 mm, with concurrent improvements in oral hygiene and swallowing function. By 6 weeks post-treatment, it further increased to 36 mm. At this point, the patient was able to resume oral feeding and undergo subsequent swallowing training ([Table 1] for a summary of specific data and [Figure 1] for the change trend). The patient’s mouth opening was maintained at this time point (6 weeks post-treatment) and during the 2-month follow-up, and their MBI score also increased from 35 to 65. Throughout the entire treatment process, no injection-related adverse reactions such as worsening dysphagia or facial muscle weakness were observed.
| Outcome measures | Pre-treatment | 1 week post-treatment | 2 weeks post-treatment | 6 weeks post-treatment | Follow-up |
|---|---|---|---|---|---|
| Mouth opening | 0 mm | 5 mm | 20 mm | 36 mm | 36 mm |
| Modified barthel index (MBI) | 35 | 35 | 40 | 55 | 65 |
DISCUSSION
In previous studies, the efficacy of BoNT-A in treating OMD after stroke has been confirmed.[9] However, to the best of our knowledge, most existing studies are limited to single-injection therapy, and there are currently no reports on its combined application with manual therapy. This study is the first to report the use of BoNT-A injections combined with TMJ manual rehabilitation therapy for the treatment of secondary closed-mouth OMD following stroke.
At present, the pathogenesis of OMD remains under investigation. Research indicates that either reduced excitability of cortical inhibitory interneurons or facilitatory effects of inhibitory interneurons originating from subcortical or other cortical structures may play a role in this disorder.[10] Based on four aspects: history of cerebral hemorrhage, clinical manifestations (sustained, involuntary contractions of the jaw-closing muscles), specialized physical examination (no dystonia in the limbs and trunk; mouth opening degree of 0 mm), imaging findings (basal ganglia lesions), and electrophysiological assessment (sustained abnormal electrical activity in the left jaw-closing muscles), the patient was diagnosed with focal dystonia secondary to stroke, specifically categorized as OMD.
In formulating the treatment plan, as the patient’s jaw-closing muscle dystonia has persisted for 2 months, long-term dystonia is prone to secondary joint adhesion, soft-tissue contracture, and TMJ dysfunction.[11] To guard against such conditions, adjuvant TMJ manual rehabilitation therapy was supplemented 24 h after BoNT-A injection. The marked improvement in the patient’s mouth opening degree post-injection (0–36 mm) also indicates that the patient’s trismus is mainly caused by a neurogenic factor, namely dystonia, with mechanical adhesion contributing minimally. This does not, however, negate the importance of manual therapy. For patients with analogs etiologies who have a suboptimal response to BoNT-A injection, adjunctive TMJ manual rehabilitation therapy is recommended for consideration.
In addition, this study employed ultrasound- and EMG-guided dual injection. Ultrasound localizes the target muscle groups to avoid accidental puncture, while EMG identifies abnormally active areas to ensure precise drug administration.This approach not only guarantees therapeutic efficacy but also reduces the total drug dose, thereby minimizing the risk of adverse reactions. The patient experienced no adverse events throughout the entire treatment course.
It should be noted that this study has the following limitations. First, as a single case report with a small sample size, its conclusions need to be validated by large-sample randomized controlled trials. Second, the follow-up period was only 2 months; constrained by the clinical follow-up protocol, the long-term sustainability of BoNT-A efficacy (the efficacy of botulinum toxin typically fades after 3–4 months). It is therefore recommended that the follow-up period be extended to more than 6 months in future research.
CONCLUSION
This case demonstrates that for severe secondary closed-mouth OMD following stroke, the comprehensive treatment of ultrasound- and EMG-guided BoNT-A injection combined with TMJ manual rehabilitation therapy can effectively improve mouth opening and oral-related functions, thereby enhancing the patient’s quality of life. Clinicians should enhance their awareness of this disorder; early diagnosis and multimodal intervention are the keys to successful treatment.
Ethical approval:
Institutional Review Board approval is not required.
Declaration of patient consent:
The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given consent for their images and other clinical information to be reported in the journal. The patient understand that the patient’s names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Conflicts of interest:
There are no conflicts of interest.
Use of artificial intelligence (AI)-assisted technology for manuscript preparation:
The authors confirm that there was no use of artificial intelligence (AI)-assisted technology for assisting in the writing or editing of the manuscript, and no images were manipulated using AI.
Financial support and sponsorship: Henan Science and Technology Project (232102310266) and the Henan Province Medical Science and Technology Research Program (SBGJ202102037).
References
- Oromandibular dystonia: A clinical examination of 2,020 cases. Front Neurol. 2021;12:700714.
- [CrossRef] [PubMed] [Google Scholar]
- Oromandibular dystonia: Demographics and clinical data from 240 patients. J Mov Disord. 2018;11:78-81.
- [CrossRef] [PubMed] [Google Scholar]
- Severe spastic trismus without generalized spasticity after unilateral brain stem stroke. Ann Rehabil Med. 2012;36:154-8.
- [CrossRef] [PubMed] [Google Scholar]
- Epidemiology of focal and generalized dystonia in Rochester, Minnesota. Mov Disord. 1988;3:188-94.
- [CrossRef] [PubMed] [Google Scholar]
- Oromandibular dystonia-a systematic review. Ann Indian Acad Neurol. 2022;25:26-34.
- [CrossRef] [PubMed] [Google Scholar]
- Oromandibular dystonia screening questionnaire for differential diagnosis. Clin Oral Investig. 2019;23:405-11.
- [CrossRef] [PubMed] [Google Scholar]
- Multilingual website and cyberconsultations for oromandibular dystonia. Neurol Int. 2018;10:7536.
- [CrossRef] [PubMed] [Google Scholar]
- Effects of onabotulinum toxin type A injections in patients with Meige's syndrome. Arq Neuropsiquiatr. 2024;82:1-7.
- [CrossRef] [Google Scholar]
- Shortened cortical silent period in facial muscles of patients with cranial dystonia. Neurology. 2000;54:130-5.
- [CrossRef] [PubMed] [Google Scholar]
- Dystonia In: StatPearls. Treasure Island, FL: StatPearls Publishing; 2026.
- [PubMed] [Google Scholar]