Not All That Is Droopy Post Ad26.COV2.S (JNJ) Vaccine Is Bell's Palsy: A Rare Case of Isolated Dorsal Pontine Stroke Causing Ipsilateral Complete Hemi-Facial Palsy.

The Ad26.COV2.S vaccine, developed by Janssen (Beerse, Belgium), the pharmaceutical wing of Johnson & Johnson (JNJ), is one of the three vaccines approved for use against coronavirus disease 2019 (COVID-19) infection in the United States. We present a case of a 66-year-old female who presented to the emergency department with a one-day history of nausea, vomiting, room-spinning vertigo, and complete right facial weakness immediately after getting vaccinated with Ad26.COV2.S. Initial workup focused on uncovering a possible association between the vaccine and Bell's palsy. However, her prior history of stroke, presence of predisposing risk factors, and additional symptoms of nausea, vomiting, and vertigo prompted further neurological testing, which revealed an isolated right pontine lacunar infarct involving the right facial colliculus, mimicking Bell's palsy. Isolated dorsal pontine lesion presenting as hemifacial palsy is very rare and can be easily missed by clinicians. Relevant history and thorough neurological examination can help guide appropriate diagnostic testing and prevent potential biases. It is crucial for clinicians to know the distinguishing features between true Bell's palsy and acute brainstem infarction masquerading as Bell's.