[Painful Claude Bernard Horner syndrome: apropos of a painless carotid artery dissection].

We report a case of post-traumatic carotid artery dissection revealed by a painless Horner's syndrome. Horner's syndrome is a neurologic emergency when it appears rapidly, spontaneously or after a trauma. Each painful Horner's syndrome must be considered as due to a homonymous carotid artery dissection until proven otherwise. One must be attentive especially because the pain may be an inconstant finding and the Horner's syndrome incomplete. Ophthalmologists must be aware of this entity because they are the first and often only practicians to be consulted. They must consider the diagnosis, ask for an immediate MRI or angio-scan, start the treatment and assume the follow-up.