Acute Vertigo After CrossFit Workout in a Young Woman With Chiari I Malformation.

CrossFit workout is associated with injuries mostly located over the spine and upper limb. Chiari I malformation (CIM) is characterized by migration of the cerebellar tonsils below the foramen magnum and this clinical condition has never been described after high-intense training such as CrossFit. A 19-year-old woman presented to the ED with acute vertigo, nausea, vomiting, and horizontal spontaneous nystagmus; symptoms began after an intense workout session. During neuro-otological examination, spontaneous positional left-beating horizontal nystagmus, normal response to bi-thermal caloric stimulations, and unremarkable cervical vestibular evoked myogenic potentials in both ears were observed; pure tone audiometry showed normal hearing. Central vertigo was suspected; therefore, an MRI was done, which identified a CIM. The patient's symptoms spontaneously improved at short term. The six-month follow-up MRI confirmed no changes. The subject completely stopped any training and remained asymptomatic over a 12-month follow-up. Our case report is the first describing CIM presented with acute vertigo after a high-intensity training.