[Causal relationship: and if "yes", and if "not"... on basis of which criterias?].

A woman was referred to us 4 days after the sudden onset of continuous rotatory vertigo. The diagnosis of a left vestibular neuronitis was made. During the investigations, a meningioma of the contralateral posterior fossa was discovered. Is there any relationship between the two disorders? The etiology of peripheral vestibular disorders remains poorly understood in most cases. Anomalies of cells surrounding the sensory organs have been demonstrated in post-mortem examination of the inner ear of patients with a vestibular deficit that could be caused by a "biological stress". Therefore there may be a link between left vestibular deficit and the mass of the right posterior fossa, considered as a fortuitous discovery, at first.