Sinusitis-Induced Guillain-Barré Syndrome

Guillain-Barré syndrome (GBS) is a heterogeneous, relatively uncommon, post-infectious, immune-mediated polyradiculoneuropathy. It is estimated to affect 1.11.8/100,000/year in Europe and North America [1]. Historically, GBS was considered to be a single disorder, but it is currently classifi ed into six clinically distinct subtypes. It can manifest as cranial nerve involvement, including bilateral facial palsy, which is observed in 45-75% of cases [2]. In most instances, bilateral facial palsy or facial diplegia (FD) manifests either as bilateral Bell's palsy or as part of the presentation of GBS [3].


Introduction
Guillain-Barré syndrome (GBS) is a heterogeneous, relatively uncommon, post-infectious, immune-mediated polyradiculoneuropathy. It is estimated to affect 1.1-1.8/100,000/year in Europe and North America [1]. Historically, GBS was considered to be a single disorder, but it is currently classifi ed into six clinically distinct subtypes. It can manifest as cranial nerve involvement, including bilateral facial palsy, which is observed in 45-75% of cases [2]. In most instances, bilateral facial palsy or facial diplegia (FD) manifests either as bilateral Bell's palsy or as part of the presentation of GBS [3].
Plasmapheresis or the administration of intravenous immunoglobulin (IVIG) are the gold standard therapies for the demyelinating form of GBS and probably for the other subtypes as well, and they reportedly shorten the course of the disease [4]. Despite recent progress in therapeutic management, GBS still results in an in-hospital mortality rate of over 2.5% and a >9% need for endotracheal intubation, which is known to be a predictor of mortality [5]. We describe the clinical presentation, radiologic fi ndings and management of a unique case of acute pansinusitis-induced GBS with isolated FD.

Case Report
An otherwise healthy 41-year-old male presented to the emergency room with rapidly progressive FD of 2 days duration. A detailed anamnesis revealed a recent diagnosis of acute rhinosinusitis that had been treated empirically with oral azithromycin for 3 days, with no signifi cant improvement in nasal congestion, purulent nasal discharge or facial pain. One day prior to admission, he noticed that his speech was altered because his tongue felt numb. He also found it diffi cult to move his mouth and close his eyes. He denied dysphagia, visual disturbances of any kind or other sensory defi cit. There was neither history of rash or arthritis in the past nor any evidence of those symptoms during this episode.

Discussion
Facial diplegia is a rare condition that occurs mainly in the context of GBS. The patient we describe was diagnosed as having GBS by means of a typical CSF laboratory analysis, including albuminocytological dissociation (elevated protein level without increase in cell count) and an EMG characteristic of bilateral facial nerve axonal damage, which is considered to be a GBS variant. Most GBS cases are associated with a clinically apparent antecedent infection. A meticulous search for a GBSprovoking infection in this patient revealed no clinical sign or symptom other than pansinusitis. Respiratory, gastrointestinal and urinary tract infections were excluded by anamnesis, physical examination, laboratory results (including urinary, blood and CSF analysis) and radiologic imaging.
Cranial nerve palsy is a well-known manifestation of complicated acute sinusitis, through cavernous sinus thrombosis (CST). The mechanism is thought to be via hematogenous spread from the paranasal sinuses through the facial venous plexus, or via direct infection from the sphenoid sinus to the adjacent cavernous sinus [6]. The typical symptoms of CST are fever, proptosis, ptosis, chemosis and orbital (III, IV and VI) cranial nerve palsy. Facial nerve palsy can not, however, be explained by the CST mechanism, due to the lack of an anatomical relationship between the cavernous sinus and the facial nerve. There is only one publication on a complicated frontal sinusitis-induced unilateral facial paresis by means of subdural empyema causing a mass effect at the upper level of the brainstem [7]. This mechanism was ruled out in the current case: our patient had no fever and showed no signs of general deterioration or meningeal disease. Moreover, his head CT did not reveal any intracranial abnormalities. We found three few publications linking acute sinusitis to GBS [8,9], of which only one was written in English [9]. This case report is unique case of isolated FD that was secondary to GBS and provoked by acute pansinusitis. There were no other signs of cranial nerve involvement, with the FEES and ophthalmic fi ndings within normal limits. We did not perform Schirmer's test to assess the greater superfi cial petrosal nerve.

Conclusion
GBS is not an uncommon pathology and one that is associated with signifi cant morbidity and mortality. The otorhinolaryngologist might be the fi rst healthcare provider to evaluate a patient with sinusitis-induced GBS. We recommend a high index of suspicion and that GBS should be considered in the differential diagnosis of every patient who presents with FD.