A 54-year-old woman, presented to the Emergency Departement (ED) with a 10-days unilateral headache and progressive pain behind the left eye. The patient had normal vital parameters and no medical history. At admission in the ED, neurological examination showed a left-sided abduction deficit (consistent with a sixth nerve palsy). The rest of the clinical examination was normal. Head CT showed no evidence of infarction, hemorrhage or mass. A lumbar punction was performed with normal opening pressure and no white blood cells.
