Lesser Known Uses of γ-Aminobutyric Acid Analogue Medications in Otolaryngology.

OBJECTIVES/HYPOTHESIS: In otolaryngology, γ-aminobutyric acid (GABA) analogues have been previously analyzed for their roles in neuropathic pain, chronic cough, tinnitus, and perioperative analgesia. The primary aim of this study is to comprehensively summarize and synthesize the existing evidence for lesser known uses of gabapentin and pregabalin in otolaryngology. STUDY DESIGN: A scoping review conducted of the available English-language literature was performed by two authors through April 1, 2021. METHODS: The Preferred Reporting Items for Systematic Review and Meta-Analysis criteria were followed, and a quality assessment of included studies was performed using the Methodological Index for Non-Randomized Studies. RESULTS: Ten studies met inclusion criteria. Three studies found that gabapentin may reduce gastrostomy tube usage and improve swallowing function in head and neck cancer patients undergoing radiation therapy (RT). Three studies suggested that gabapentin may help reduce opiate use when used as a primary analgesic in patients with radiation-induced mucositis. One study demonstrated that pregabalin-reduced trismus severity in patients with radiotherapy-induced trismus. One study demonstrated gabapentin may be useful in patients with phonasthenia. Two studies demonstrated that GABA analogues may be a useful adjunct in patients with globus pharyngeus in the context of likely laryngeal sensory neuropathy. CONCLUSIONS: The most promising potential uses for GABA analogues identified in this review are for improving swallowing, trismus, and narcotic overuse after RT. The benefit of GABA analogues for improving nonorganic voice disorders is also promising while the benefit for globus pharyngeus when possibly related to laryngeal sensory neuropathy is inconclusive. Laryngoscope, 132:954-964, 2022.

Atraumatic trismus induced by duloxetine: an uncommon presentation of acute dystonia.

Atraumatic trismus can be one of the presentations of medication-induced acute dystonia, particularly by antipsychotics and less commonly antidepressants. A case of an unusual emergency presentation of atraumatic trismus on initiation of duloxetine is reported. The patient was a 40-year-old woman experiencing sudden difficulty in mouth opening and speaking due to a stiffened jaw after taking 5 days of duloxetine prescribed for her fibromyalgia-related chest pain. Assessment of vital signs is prudent to ensure there is no laryngeal involvement. Other physical examinations and her recent investigations were unremarkable. She was treated for acute dystonia and intravenous procyclidine was given together with oral diazepam. Her symptoms improved immediately and her duloxetine was suggested to be stopped. To our knowledge, this is the first case of isolated trismus induced by duloxetine. Clinicians should be aware of this risk, especially considering the limitation of important physiological functions (such as swallowing, eating, etc) associated with this condition.

Sertraline-Induced Rhabdomyolysis, Trismus, and Cardiac Arrest in a Child.

Selective serotonin reuptake inhibitors are a commonly used and often effective class of medications in the treatment of mood disorders such as anxiety and depression. Sertraline (1S,4S-N-methyl-4-[3,4-dichlorophenyl]-1,2,3,4-tetrahydro-1-naphthylamine [Zoloft; Pfizer, New York City, NY]) is a frequently used selective serotonin reuptake inhibitor that has shown efficacy in children, adolescents, and adults. We report the case of a 13-year-old boy with sertraline-induced rhabdomyolysis and renal failure, trismus, and cardiopulmonary arrest. Pharmacogenetic testing later revealed our patient had serotonin transporter polymorphisms and enzymatic alterations that put him at risk for increased levels of sertraline and greater likelihood for untoward side effects.

Local anesthetic-induced myotoxicity as a cause of severe trismus after inferior alveolar nerve block.

A case of a 60-year-old man with severe trismus after inferior alveolar nerve block is presented. MRI scans as well as histologic examination revealed muscle fibrosis and degeneration of the medial part of the left temporal muscle due to myotoxicity of a local anesthetic agent.

Complications of botulinum toxin injection for masseter hypertrophy: Incidence rate from 2036 treatments and summary of causes and preventions.

BACKGROUND: Masseter hypertrophy is a common, prominent feature in many Asian patients, and correction procedures are often requested for esthetic reasons. Toxin masseter injections have a high efficacy and safety profile, but the risks of a variety of side effects or complications remain. OBJECTIVES: The categorization of various complications was based on etiology, with a presentation of the author's own incidence rates for consideration and comparison. METHODS: Six hundred and eighty patients received a total of 2036 sessions of toxin injection for masseter hypertrophy from 2011 to 2016, and complications or complaints were recorded through follow-up on a by-treatment basis. Complications were grouped together based on etiology and discussed. RESULTS: Of 2036 sessions, temporary mastication force decrease was reported after 611 (30%), bruising after 51 (2.5%), headaches after 12 (0.58%), smile limitation after 3 (0.15%), paradoxical bulging after 10 (0.49%), sunken cheeks (subzygomatic volume loss) after 9 (0.44%), and sagging after 4 (0.20%). CONCLUSIONS: Masseter injections remain very safe. To further decrease the incidence rate, injections should only be inside the recommended safety zone, a quadrilateral within the muscle that avoids most important local structures. Keeping injections inside the safe zone, and ideally in 3-4 different locations at least 1 cm from any border, is crucial for the prevention of complications.

Acute masseter dystonia in a pediatric patient receiving aripiprazole and methylphenidate following induction of general anesthesia.

An 11-year-old male receiving aripiprazole, methylphenidate, and clonidine developed acute masseter dystonia inhibiting tracheal intubation after induction of general anesthesia with propofol and rocuronium. Following emergence, he had trismus and jaw discomfort. Psychiatry consultation suspected an acute dystonic reaction, so diphenhydramine was administered intravenously which resolved symptoms. We suspect chronic aripiprazole and methylphenidate usage combined with propofol administration in the short-term absence of methylphenidate made this patient susceptible to dystonic reactions.

[Propofol-induced trismus, causing an unanticipated difficult intubation due to masseter spasm]. / Propofolinduceret masseterspasme som årsag til trismus og uventet vanskelig intubation.

We report a case of a 54-year-old male who within a month had two events of bilateral masseter spasm (BMS) at induction of anaesthesia. The first time BMS caused unanticipated difficult intubation after infusion of remifentanil and propofol, and conseqeuently the general anaesthesia was terminated. The second time an awake fiberoptic intubation was planned followed by infusion of propofol, and once again there was a BMS breakout. This side effect of propofol has been reported to the Danish Health and Medicines Authority.

Anesthetic efficacy of a combination of 0.9 M mannitol plus 68.8 mg of lidocaine with 50 µg epinephrine in inferior alveolar nerve blocks: a prospective randomized, single blind study.

The purpose of this prospective randomized, single blind study was to determine the anesthetic efficacy of 68.8 mg of lidocaine with 50 µg epinephrine compared to 68.8 mg lidocaine with 50 µg epinephrine plus 0.9 M mannitol in inferior alveolar nerve (IAN) blocks. Forty subjects randomly received 2 IAN blocks consisting of a 1.72-mL formulation of 68.8 mg lidocaine with 50 µg epinephrine and a 5-mL formulation of 68.8 mg lidocaine with 50 µg epinephrine (1.72 mL) plus 0.9 M mannitol (3.28 mL) in 2 separate appointments spaced at least 1 week apart. Mandibular anterior and posterior teeth were blindly electric pulp tested at 4-minute cycles for 60 minutes postinjection. No response from the subject to the maximum output (80 reading) of the pulp tester was used as the criterion for pulpal anesthesia. Total percent pulpal anesthesia was defined as the total of all the times of pulpal anesthesia (80 readings), for each tooth, over the 60 minutes. One hundred percent of the subjects had profound lip numbness with both inferior alveolar nerve blocks. The results demonstrated that the 5 mL-formulation of 68.8 mg lidocaine with 50 µg epinephrine plus 0.9 M mannitol was significantly better than the 1.72-mL formulation of 68.8 mg lidocaine with 50 µg epinephrine for all teeth, except the lateral incisor. We concluded that adding 0.9 M mannitol to a lidocaine with epinephrine formulation was significantly more effective in achieving a greater percentage of total pulpal anesthesia (as defined in this study) than a lidocaine formulation without mannitol. However, the 0.9 M mannitol/lidocaine formulation would not provide 100% pulpal anesthesia for all the mandibular teeth.