Elucidation of the pathogenesis and effective treatment of autism spectrum disorders is one of the challenges today. In this study, we examine hair zinc concentrations for 1,967 children with autistic disorders (1,553 males and 414 females), and show considerable association with zinc deficiency. Histogram of hair zinc concentration was non-symmetric with tailing in lower range, and 584 subjects were found to have lower zinc concentrations than −2 standard deviation level of its reference range (86.3–193ppm). The incidence rate of zinc deficiency in infant group aged 0–3 year-old was estimated 43.5 % in male and 52.5 % in female. The lowest zinc concentration of 10.7 ppm was detected in a 2-year-old boy, corresponding to about 1/12 of the control mean level. These findings suggest that infantile zinc deficiency may epigenetically contribute to the pathogenesis of autism and nutritional approach may yield a novel hope for its treatment and prevention.

Oromandibular dystonia is a focal dystonia involving the masticatory and tongue muscles, causing difficulties in speech or mastication. We treated 13 patients with this condition by injecting diluted lidocaine and alcohol intramuscularly. This method is aimed at reducing muscle spindle afferent activity. The symptoms had been resistant to other therapies such as pharmacotherapy or dental treatment. All patients showed clinical improvement after this therapy with reduced EMG activities in the affected muscles, whereas control injection of normal saline gave no changes in EMG activities. The overall subjective improvement was 57.7 +/- 25.1% (mean +/- standard deviation) in a self-rating scale. The mean response of the jaw elevator muscles (70 +/- 13.1%) was significantly higher (p < 0.02, t test) than that of the depressor muscles (38 +/- 28.4%). Despite the precise mechanism being unknown, this difference might be related to the smaller number of muscle spindles in the depressor than the elevator muscles. This therapy is useful for the treatment of drug-resistant oromandibular dystonia.

This screening tool can be used to distinguish oromandibular dystonia from temporomandibular disorders.

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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.

Oromandibular dystonia is a focal dystonia that manifests as involuntary masticatory and/or tongue muscle contractions. Jaw opening, jaw deviation, and jaw protrusion types of oromamdibular dystonia are caused by involuntary contraction of the lateral pterygoid muscles. The medial pterygoid can be very hyperactive in jaw closing dystonia as a result of the so-called "whack-a-mole phenomenon," after repeated botulinum toxin injections into the masseter and temporalis muscles. The more accurately the botulinum toxin is injected into the muscles, the more likely the improvement in the patient's symptoms, and the lower the risk of complications, such as hematoma or arterial bleeding. Both pterygoid muscles can be accessed by intra-and extraoral routes. Safe and correct injection of botulinum toxin into both pterygoid muscles is described in this video. With understanding of the anatomy of the muscles, indications for injection, and technique of needle placement, injection of botulinum toxin into the lateral and medial pterygoid muscles is safe and effective for oromandibular dystonia.

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ZusammenfassungEine oromandibuläre Dystonie ist charakterisiert durch unwillkürliche tonische oder klonische Spasmen der Kau- und / oder Zungenmuskulatur bzw. der Muskeln im stomatognathen System. Sie wird oft fälschlicherweise als kraniomandibuläre Dysfunktion oder psychiatrische Erkrankung diagnostiziert. Aufgrund der klinischen Bilder wird die oromandibuläre Dystonie in 6 Subtypen (Kieferschluss-, Kieferöffnungs-, Zungen-, Kieferdeviations-, Kieferprotrusions-, und Lippendystonie) eingeteilt. Es gibt verschiedene Behandlungsmethoden, z. B. Injektion von Botulinum-Toxin, Muskelafferenzblockierung (Injektionen von Lidocain und Äthanol in die Kau- oder Zungenmuskulatur zur Blockierung der Afferenzen der Muskelspindeln), Aufbissschiene und chirurgische Eingriffe (Coronoidotomie). In vielen Fällen können aufgrund des Subtyps die Symptome durch eine Kombination dieser Methoden erfolgreich behandelt werden. In diesem Leitthema werden spezielle Therapieempfehlungen für jeden Subtyp beschrieben. Eine genaue Diagnose und Behandlung einer oromandibulären Dystonie erfordert umfassende Kenntnisse und Fähigkeiten sowohl in der Mund-, Kiefer- und Gesichtschirurgie als auch in der Neurologie. Daher ist die Zusammenarbeit zwischen diesen Abteilungen sehr wichtig.