Clinical Reasoning: a 54-year-old man with unilateral weakness and vascular risk factors.

Vasileios Lioutas, MD Jose R. Romero, MD Michael S. Kleinman, DO James W. Wang, MD Michael D. Perloff, MD, PhD SECTION 1 A 54-year-old man with history of poorly controlled hypertension and hyperlipidemia presented with right arm and leg weakness while exercising. Onset was preceded by a few minutes of acute, right-sided, “stabbing” neck pain. He had no dysarthria, facial weakness, visual disturbance, loss of sensation, chest pain, or palpitations. Blood pressure was 178/78 mm Hg. Cranial nerves were intact, without nystagmus. Comprehension, repetition, and naming were intact. Distal right upper extremity weakness affected extensor more than flexor muscle groups. Right lower extremity weakness was more prominent in flexor than extensor muscle groups. Deep tendon reflexes were symmetric and increased at the ankles. A right Babinski sign was present. There was no dysmetria and screening sensory examination revealed no deficit to light touch and temperature. His gait was wide-based and unsteady. NIH Stroke Scale score was 2. Cardiovascular examination demonstrated normal rhythm and auscultation of carotid arteries and heart sounds. Intracranial hemorrhage was excluded with a negative noncontrast head CT, and aspirin 81 mg was administered. EKG revealed normal sinus rhythm. Brain MRI, obtained approximately 6 hours after initiation of symptoms, was negative for stroke. Magnetic resonance angiography (MRA) revealed lack of flow-related signal in the right vertebral artery extracranially extending intracranially.