[Pathology of cranial nerves: diagnostic orientation and aphorisms]

Despite the remarkable progress of Neuroradiology, the etiologic diagnosis of cranial nerve disorders remains, because of the numerous potential causes, one of the most difficult clinical problems in Neurology. It requires a perfect collaboration between neurologists, ophthalmologists, and ENT specialists, and also between clinicians and radiologists. First of all however, it is based on a rigorous clinical analysis in order to determine the site of the lesion and to guide complementary investigations. The purpose of this short paper is to provide a brief outline of this clinical approach and to recall some aphorisms which are essential to keep in mind when dealing with this pathology.