Case Report Threat of a Cycle Proof: Vertebral Artery Dissection Associated with Posterior Inferior Cerebellar Artery Infarction Francisco Monteiro , Pedro Oliveira, and Artur Cond´ e Department of Otorhinolaryngology, Head and Neck Surgery, Hospital Center of Vila Nova Gaia/Espinho, Rua Conceição Fernandes s/n, 4434-502 Vila Nova de Gaia, Portugal Correspondence should be addressed to Francisco Monteiro; francisco.c.monteiro@gmail.com Received 6 September 2018; Revised 14 November 2018; Accepted 12 December 2018; Published 27 December 2018 Academic Editor: Abrão Rapoport Copyright © 2018 Francisco Monteiro et al. is is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. is paper presents a case of a perfectly healthy 36-year-old male, who went to the emergency department with a clinical picture of diffuse headache, dizziness, and asthenia with 3 days of evolution, after a long cycling race. He was admitted to the ENT Department with suspected diagnosis of peripheral vertigo. e patient developed hypoesthesia of the face, diplopia, right lateropulsion, and Romberg with preferential rightward fall, and imaging studies demonstrated an extracranial vertebral artery dissection concomitant with PICA territory infarction. is is a rare described case of a vertebral artery dissection concomitant with an infarction of the PICA territory. is case demonstrates the importance of maintaining a high degree of suspicion of stroke in patients with signs/symptoms of nystagmus/ vertigo and the relevance of magnetic resonance imaging instead of tomography in the detection of these serious clinic conditions. 1. Introduction Vertebral artery dissection (VAD) is a relatively rare event but a major cause of stroke in young and middle-aged patients [1]. Only twenty percent of ischemic events occur in the posterior circulation due to atherosclerosis, arterial embolization, or arterial dissection [2]. e concomitance of vertebral arterial dissection associated with infarction of the territory of the posterior inferior cerebellar artery (PICA) is an even rarer event. e truth is that this young man who had been on a three-hour bike ride went to the emergency department with a common complaint of vertigo and presented a rare association of a vertebral artery dissection with PICA infarction. 2. Case Presentation eauthorsreportacaseofa36-year-oldactivemanwithno relevant medical history, who went to the emergency de- partment due to a diffuse headache and dizziness, with a 3- day course after a long bicycle ride. e patient referred that these symptoms were usual after an intense physical activity as he regularly performed in cycle races. He was admitted to Neurology observation in the Emergency Room (ER). On examination, there were no evident de novo neurological signs. A cerebral CT was performed, and it was normal. He was then referred to Ear, Nose, and roat (ENT) obser- vation due to suspicion of peripheral vertigo. e ENT examination revealed a horizontal-rotatory nystagmus, with rapid phase to the right, that was exhaust- ible in the gaze, however with a normal head impulse test. e Neurology ER team assumed noncentral vertigo since at this time there was no evidence of any signs of a central cause, neither in physical examination nor in the imaging test performed. is diagnosis seemed the most likely to the team. He was admitted to the ENT ward, and symptomatic and medical treatment was initiated. ere was clinical stabili- zation until the 3 rd day, when sudden symptoms and signs emerged: ipsilateral downward fall, right hemifacial pares- thesia, right hemifacial pain, ipsilateral limb ataxia with ataxic gait, and diplopia. An emergent magnetic resonance angi- ography revealed “(...) hyperintense area in T2 and T2 FLAIR in the dorsal lateral aspect of the right bulb that in the diffusion study showed a marked restriction (...).” In the arteriography study, it was identified that “an occlusion of the right vertebral artery was identified in segment V2, after showing progressive reduction and contour irregularity” (Figure 1). Hindawi Case Reports in Otolaryngology Volume 2018, Article ID 5387607, 3 pages https://doi.org/10.1155/2018/5387607