Case Presentation: This patient was a previously healthy 33-year-old Native American female that had initially presented to urgent care with right-sided facial weakness and was prescribed steroids and valacyclovir. Two days later, she began to develop left-sided facial weakness despite treatment. Over the course of the next five days, the patient experienced worsening bilateral facial weakness, decreased taste, as well as painful paresthesias in the proximal upper extremities and distal lower extremities, which prompted her to seek further medical attention. Due to limited resources at the outside facility, she was transferred to our care for neurology consultation. Physical exam revealed bilateral nasolabial fold flattening, inability to completely close her eyes, decreased sensation throughout the face consistent with a bilateral House-Brackmann grade V CN VII palsy. On the day of her presentation, an urgent lumbar puncture was performed along with neuroimaging. Cerebrospinal fluid (CSF) studies revealed significant albuminocytologic dissociation with a protein of 112, and a diagnosis of atypical GBS was made. Empiric treatment with valacyclovir was continued and nephrology was immediately consulted for plasma exchange (PLEX). After five days of treatment with PLEX, the patient had no significant improvement in her symptoms, so treatment with intravenous immunoglobulin (IVIG) was initiated. At this point, additional CSF studies resulted, which were positive for CMV IgG. The remainder of the infectious and autoimmune workup was negative. Fortunately, the patient’s symptoms began to significantly improve on the new treatment regimen, and after completion of a 4-day course of IVIG, her symptoms had improved and she was discharged with neurology follow-up.
Discussion: Most cases of facial nerve palsy are unilateral, and about 50% of all cases are Bell’s palsy, which is a very well-known idiopathic nerve palsy. Bilateral facial nerve palsy, in contrast, is an exceedingly rare clinical entity, and is estimated to make up about 2% of all facial nerve palsies. The differential diagnosis for bilateral facial nerve palsy is vast and includes metabolic, congenital, vascular, neurologic, infectious, neoplastic and traumatic etiologies. In approaching the diagnostic evaluation of a patient with this presentation, the clinician must take a very thorough history and perform a comprehensive exam in order to elucidate the potential cause. The history should focus on symptom characterization (e.g. time sequence of onset, synchronicity, taste change), associated symptoms (e.g. diplopia, facial numbness, otological symptoms, aphasia, vesicles), relevant risk factors (e.g. viral prodrome, camping, immunizations), and prior palsy history. In this case the relatively quick onset, viral prodrome (presence of cough in the two weeks preceding her presentation) with known infectious exposure (worked as a caregiver) was highly suggestive of an infectious etiology. Diagnostic evaluation should be broad and include workup for infectious etiologies, autoimmune and vasculitis panels, etc. Lumbar puncture is typically indicated. Neuroimaging should be obtained to evaluate for any space occupying lesions.
Conclusions: Although CMV is the second-leading cause of GBS, this case demonstrates a very atypical presentation of GBS and emphasizes the importance of maintaining a broad differential when approaching acute onset neurologic symptoms, in particular with bilateral facial nerve palsy.