We report the case of a 13-year-old boy who presented at the emergency department for nausea and vomiting with ataxia and dissymmetry. He had strabismus as a consequence of palsy of the VI cranial nerve when 9 months old that was attributed to an allergy to penicillin. He had no relevant family history. Urgent CT and posterior MRI examination showed multiple supratentorial and infratentorial cavernous angiomas, one of which was located in the brainstem and presented acute hemorrhage, causing the symptoms. Angiography performed later showed no evidence of vascular malformations. The patient was initially managed conservatively, but the cavernous angioma in the brainstem was surgically extirpated after the patient's condition progressively worsened.