Abstract
Surgical approaches to the temporomandibular joint (TMJ) have been designed specifically to minimize injury to the temporal branch of the facial nerve. In spite of this, facial nerve dysfunction occurs in 1–32% of patients undergoing TMJ surgery. Ramsay Hunt syndrome is characterized by peripheral facial paralysis that often involves other cranial nerves, mostly cranial nerve VIII. The pathology is attributed to the reactivation of latent varicella zoster virus in the geniculate ganglion. The diagnosis is based mostly on history and physical findings. Surgical procedures have been known to reactivate varicella zoster virus, but Ramsay Hunt syndrome subsequent to TMJ surgery has not been described yet. This report describes a case of Ramsay Hunt syndrome associated with TMJ surgery. Because of the relatively high incidence of facial nerve dysfunction associated with TMJ surgery, patients with varicella zoster virus reactivation may initially be misdiagnosed with iatrogenic facial palsy, or vice versa.
Temporomandibular joint (TMJ) surgery is a frequent procedure in maxillofacial surgery, performed mostly in cases of trauma or for the resolution of TMJ diseases. The most common surgical approaches to the joint, namely the pre-auricular, endaural, post-auricular, and submandibular, aim to avoid the temporal branch of the facial nerve (the frontalis nerve), which crosses the zygomatic arch 8–35 mm in front of the anterior concavity of the external auditory canal, within the undersurface of the temporoparietal fascia.
Nonetheless, transient neuropraxia of the temporal branches of the facial nerve occurs in 1–32% of TMJ surgeries. The most common symptoms of such complications are an inability to wrinkle the brow up, to raise the eyebrow, or to close the eyelids tightly. In the majority of cases this adverse effect resolves within 9–14 weeks, but it may endure for up to 6 months.
In 1907, James Ramsay Hunt described a syndrome of otalgia, auricular vesicles, and peripheral facial paralysis and hypothesized that this syndrome resulted from a herpetic infection of the geniculate ganglion (nerve VII). This physiopathology is associated with the reactivation of varicella zoster virus (VZV) in the geniculate ganglion. Because of the close proximity of the geniculate ganglion to the vestibulocochlear nerve within the bony facial canal, deficiencies related to cranial nerve VIII, such as tinnitus, hearing loss, nausea, vomiting, vertigo, and nystagmus, can also appear.
Reports have been published of Ramsay Hunt syndrome (RHS) with multiple cranial nerve involvement. Aviel and Marshak found involvement of cranial nerves VII, VIII, IX, V, X, and VI, in decreasing order, while involvement of cranial nerves I, II, III, IV, XI, and XII was rare.
Different surgical procedures have been described as triggers for virus activation. A case of RHS following TMJ surgery is reported herein.
Case report
A 20-year-old female, a former patient, was admitted to the Department of Oral and Maxillofacial Surgery complaining of right facial nerve paralysis that had developed 2 weeks after a right high condylectomy for condylar hyperplasia. The patient had experienced immediate postoperative mild dysfunction of the right temporal branch of the facial nerve that included only a slight difficulty in lifting the right eyebrow. This weakness resolved entirely within 7 days postoperative. However, 7 days later (14 days post-surgery), paralysis of all branches of the facial nerve appeared suddenly. The patient’s medical history was unremarkable, except for an allergic reaction to aciclovir.
On extraoral examination on postoperative day 14, the patient had mild pre-auricular tender swelling, combined with complete paralysis of the temporal branch of the facial nerve and decreased function of the buccal and mandibular branches on the right side (House–Brackmann grade V). Computed tomography with iodine as contrast material revealed oedema of the pre-auricular area without any evidence of collection.
The differential diagnosis of Bell’s palsy versus postoperative infection enabled the commencement of steroidal treatment with intravenous dexamethasone combined with empirical antibiotic treatment with cefazolin (Ancef) and metronidazole (Flagyl). The patient was guided to use eye lubrication drops on the ipsilateral side. Two days after admission (16 days post-surgery), the patient complained of heaviness of the right mandible. A sensory examination found complete anaesthesia of the inferior and superior alveolar nerves. At this point, based on her history and physical findings, it was suspected that the patient had RHS; she was sent for a hearing test, and indeed a hearing impairment was diagnosed. The acoustic (stapedius) reflex for the right side was not repeatable. On day 8 following admission (22 days postoperative), herpetic blisters appeared on the skin of the right pre-auricular area, anterior to the surgical scar ( Fig. 1 ). The patient was not treated with aciclovir because she had developed angioedema during a previous use.
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