[Partial Horner's syndrome and facial pain: a diagnosis one should not miss].

Internal carotid artery dissection typically manifests as an unilateral facial or latero-cervical pain, is often accompanied by an oculosympathetic palsy (myosis and palpebral ptosis) and may be followed by cerebral or retinal ischemia. Deficits of the IXth to XIIth cranial nerves or a pulsatile tinnitus have been described. These symptoms challenge our clinical skills and call for an early diagnosis in order to prevent ischemic complications. Both helical computed tomographic angiography and transcranial ultrasonography coupled with Doppler flow colour are excellent first-line imaging techniques. Conventional angiography has been replaced by magnetic resonance techniques as gold standard. In this article, we describe the case of a patient evaluated at our outpatient clinic and review briefly the literature on this topic.