Oral management for a patient with trismus accompanied by Isaacs’ syndrome: a case report

TL;DR

A patient with Isaacs’ syndrome and trismus received successful dental treatment after plasmapheresis temporarily improved mouth opening.

Contribution

This case report demonstrates that plasmapheresis can temporarily alleviate trismus in Isaacs’ syndrome, enabling dental interventions.

Findings

Plasmapheresis increased the patient's mouth-opening distance from 20 mm to 35 mm.

Dental extraction and restoration were successfully performed during the temporary improvement in mouth opening.

Collaboration between neurologists and dentists is crucial for managing dental care in patients with Isaacs’ syndrome.

Abstract

Isaacs’ syndrome, also known as neuromyotonia or peripheral nerve hyperexcitability, is a rare disorder that affects the peripheral nervous system. Clinical findings include cramps, fasciculations, and myokymia; however, there are few reports of dental treatment for trismus.

A patient with trismus due to Isaacs’ syndrome experienced swelling and pain in the gingiva surrounding his right lower first molar. He was diagnosed with chronic apical periodontitis by a dentist near his home. However, the patient was informed that dental treatment and medication could not be administered because of the presence of Isaacs’ syndrome, and he visited the Geriatric Dentistry and Perioperative Oral Care Center at Kyushu University Hospital 2 weeks later. The patient’s painless mouth-opening distance (between incisors) was 20 mm at that time, and medication, including amoxicillin capsules and acetaminophen, was administered because the dental extraction forceps or endodontic instruments were difficult to insert into the oral cavity for treatment. Two months after his initial visit, the patient visited us complaining of pain in the same area. However, he had recently undergone plasmapheresis treatment in neurology to alleviate limited mouth opening and systemic myalgia, resulting in a pain-free mouth-opening distance of approximately 35 mm. During this temporary period in which he had no restriction in mouth opening, we performed tooth extraction and bridge restoration on the mandibular right first molar and created an oral appliance for sleep bruxism.

Plasmapheresis therapy transiently reduced trismus, rendering dental interventions feasible, albeit temporarily. This case report underscores the importance of close collaboration between neurologists and dentists who encounter similar cases while furnishing valuable insights to inform dental treatment planning.

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