Botulinum Neurotoxin Therapy for Lingual Dystonia Using an Individualized Injection Method Based on Clinical Features

Abstract

Lingual dystonia is a debilitating type of oromandibular dystonia characterized by involuntary, often task-specific, contractions of the tongue muscle activated by speaking or eating. Botulinum neurotoxin (BoNT) has been used to treat lingual dystonia; however, it is known to cause serious complications, such as dysphasia and aspiration. The purpose of this study was to evaluate the efficacy and adverse effects of individualized BoNT therapy for lingual dystonia. One-hundred-and-seventy-two patients (102 females and 70 males, mean age: 46.2 years) with lingual dystonia were classified into four subtypes based on symptoms of involuntary tongue movements: protrusion (68.6%), retraction (16.9%), curling (7.6%), and laterotrusion (7.0%). Patients were treated with BoNT injection into the genioglossus and/or intrinsic muscles via individualized submandibular and/or intraoral routes. Results were compared before and after BoNT therapy. Botulinum neurotoxin was injected in 136 patients (mean: 4.8 injections). Clinical sub-scores (mastication, speech, pain, and discomfort) in a disease-specific rating scale were reduced significantly (p < 0.001) after administration. Comprehensive improvement after BoNT injection, assessed using the rating scale, was 77.6%. The curling type (81.9%) showed the greatest improvement, while the retraction type showed the least improvement (67.9%). Mild and transient dysphasia occurred in 12.5% of patients (3.7% of total injections) but disappeared spontaneously within several days to two weeks. No serious side effects were observed. With careful diagnosis of subtypes and a detailed understanding of lingual muscle anatomy, individualized BoNT injection into dystonic lingual muscles can be effective and safe.

Treatment of Blepharospasm and Oromandibular Dystonia with Botulinum Toxins

“…These injections are medial to the digastric injections. They should be at least 1 cm into the tissue because the genioglossus is deep to the subcutaneous tissue as well as the mylohyoid and geniohyoid [31]. Injection into the orbicularis oris to reduce lip movement or pursing is problematic due to cosmesis concerns for potential mouth asymmetry, difficulty drinking thin liquids, and drooling caused by focal weakness.…”

Childhood-Onset Spinocerebellar Ataxia 3: Tongue Dystonia as an Early Manifestation

“…33 When other muscles are involved, this treatment is not appropriate due to the risk of causing airway obstruction. 34 However, we were not able to offer the botulinum toxin option to our patient as we do not have the support of a full-time neurologist and the drug is not available in our community. 35,36 Treatment otherwise consists of the usual strategies employed in dystonia.…”

Development and Validation of a Disease-Specific Oromandibular Dystonia Rating Scale (OMDRS)

“…Ninety-two de novo patients (59 women and 33 men) were assessed 4 weeks after the first injection of botulinum toxin (Botox R , Allergan; Irvine, CA) to evaluate the capability of OMDRS to detect therapeutic changes. Botulinum toxin therapy was performed as previously described (8,27,28). OMDRS scores were statistically compared between baseline and 4 weeks after botulinum toxin therapy.…”

“…Oromandibular dystonia was diagnosed based on the characteristic clinical features of focal dystonia, such as stereotypy, task specificity, sensory tricks, overflow phenomenon, morning benefit, co-contraction, and electromyographic findings, as described previously (2,6,8). All patients involved in this study provided written informed consent after receiving a full explanation of the planned treatment.…”

“…Most of these symptoms can result in impaired activities of daily living, social embarrassment, cosmetic disfigurement, and a significant impact on a patient's overall quality of life (6). Upper airway obstruction due to temporomandibular joint dislocation resulting from severe jaw opening dystonia (7) or aspiration pneumonia related to lingual dystonia (8,9) can be lifethreatening in some patients. The symptoms and clinical features may be significantly more variable, critical, and complicated than those observed in other types of focal dystonia.…”