Severe Spastic Trismus without Generalized Spasticity after Unilateral Brain Stem Stroke

Abstract

A 62-year-old female patient diagnosed with left brain stem stroke 2 months ago was admitted to our clinic for rehabilitation. She had no generalized spasticity on both extremities, but could open her mouth only approximately 2 mm between her upper and lower teeth due to severe trismus. On needle electromyography, the left masseter muscle showed paradoxically increased muscle activity during mouth opening. We injected 50 units of type A botulinum toxin (Botox®) into the left masseter muscle, and 20 units into the left temporalis muscle with guidance of ultrasonography. The interincisal distance increased to 8 mm on the 3rd day after injection, and 9 mm on the 4th day. One month later, the interincisal distance increased to 14 mm. The increased interincisal distance was maintained for 13 months after injection, and the quality of hygienic care and compliance of oral stimulation therapy also improved.

Impact of Hemorrhagic Stroke on Molar Bite Force: A Prospective Study

“…These clinical signs favor the weakening of the muscular system, including the muscles used in mastication, triggering a decrease in muscle strength. Literature shows that the masseter muscle is affected by the generalized spasticity in stroke, limiting mouth opening due to trismus (Seo et al, 2012). In this study, the sensation of the resistance of the masticatory muscles or head and neck muscles to passive stretching in individuals with hemorrhagic stroke was not evaluated.…”

Trismus caused by paraneoplastic brainstem encephalitis

“…Trismus can develop because of both articular (temporomandibular joint problems) and extra-articular causes. Reported neurological causes of trismus include brainstem stroke,8 brainstem encephalitis or encephalopathy,9 and tuberculous meningitis10 (table 2). …”

Botulinum Toxin A for Spastic Trismus Due to Brain Stem Encephalitis in a Pediatric Intensive Care Setting: A Unique Case Report

“…12 Seo et al used a dose of 50 units to masseter and 20 units to temporalis for trismus in a 62-year-old female patient with brain stem stroke. 13 In our patient, we decided on the dosage of 25 units each to temporalis and masseter muscles based on severity of the spasticity in the temporalis and masseter muscles and weight of the patient.…”