A 30-year-old male professional swimmer suddenly complained of moderate headache, neck pain, unilateral left facial weakness, and feelings of tingling and paresthesia on the left side of his body and face, a few minutes following head and body stretching exercises in land. There was no history of major head or neck trauma or manipulation. Also, he had not practiced any diving skills in the past. He had severe ataxia and could not walk without help, but he did not have any loss of consciousness. Acute infarction of the left cerebellum was diagnosed after brain computed tomography (CT) and magnetic resonance imaging (MRI) (with contrast) studies. Magnetic resonance angiography (MRA) of the brain was also done, which was normal. There was no history of major disease in his past medical history. Cardiac and rheumatological workups were normal. His brain and neck MRI (with contrast) and cervical MRA can be seen in -.