A patient presents with sudden onset true vertigo with nausea after a URI. What is the likely diagnosis?

The presentation of sudden onset true vertigo accompanied by nausea following an upper respiratory infection (URI) strongly supports the diagnosis of vestibular neuronitis. This condition is characterized by a viral infection affecting the vestibular system, often after a viral illness like a URI. The inflammation of the vestibular nerve results in intense spinning sensations, or vertigo, which can be exacerbated by head movements, along with associated symptoms of nausea and imbalance.

In this scenario, the patient's recent URI serves as a classic precipitating factor for vestibular neuronitis, as it is not uncommon for viral infections to lead to this vestibular disorder. The acute onset of vertigo that is typically severe is another hallmark of vestibular neuronitis, differentiating it from other vestibular disorders that may have different onset patterns or associated findings.

Understanding these connections reinforces the diagnosis of vestibular neuronitis in this context, where the combination of sudden vertigo, nausea, and the patient’s recent URI is a defining characteristic of the condition.