Definition

The dermatological Crowe sign characterized by the presence of skin lentigines (of skin) axillary (in the armpit) in Recklinghausen neurofibromatosis. Also called benign melanoma, Nevus Pigmentosus et pilosus common, grain of beauty, Freckle or lentigo, the lentigines are small spots dye skin, sometimes slightly embossed, that we see in particular at the level of the face, hands and neck. The ophthalmologic Crowe sign (for eye) is characterized by compression and therefore a restriction of the jugular vein (vein of the throat) internal resulting dilation (opening of the calibre of the arteries) of the veins of the retina, which is visible at the bottom of eye. When the patient of a cavernous sinus thrombosis (blood clot), dilation of retinal veins does not occur with affection. In this case, the Crowe sign is positive. 

Anatomy

Cavernous sinus is the venous formation located at the base of the skull, outside the Turkic saddle. The Turkic saddle is a depression of the os sphénoïde where the pituitary is housed. The pituitary is (endocrine) gland located below the brain, below the hypothalamus. The pituitary gland secretes the stimulines (varieties of hormone) that have an action on the other endocrine glands. The sphénoïde is a bone of the head forming the central floor of the braincase.Cavernous sinus is crossed by the carotid artery and oculomoteurs nerve and eye of the trigeminal nerve branches. These are derived from:

• The third cranial pair.
• The fourth cranial pair.
• The fifth cranial pair.

The cranial nerves are nerves in the brain.