Not sure about the blood flow. Again my feeling is the hair in the furrows only looks thicker because the hairs follicles are squeezed together.More of an optical illusion. If there was a way to stretch it out, I feel all the hair would look even and consistent . I have read some posts on stress causing it, to over abundant growth hormone levels due to pituitary gland, to wearing a cap too tightly. I have read we are 1 in 100,000. Like you said. I see more and more people with it
Here is the info I usually find
Cutis verticis gyrata (CVG) is a superficial medical condition usually associated with thickening of the scalp.
The condition was first described by Alibert in 1837
Sufferers show visible folds, ridges or creases on the surface of the top of the scalp. The number of folds can vary from 2 to roughly 10 and are typically soft and spongy. These folds cannot be corrected with pressure. The condition typically affects the central and rear regions of the scalp, but can sometimes can involve the entire scalp.
Hair loss can occur over time, where the scalp thickens, though hair within any furrows remains normal.
Thus far, due to the (apparent) rarity of the condition, limited research exists and causes are as yet undetermined. What is known, is that the condition is not exclusively congenital.
Classifications
CVG is classified according to the presence, or lack of, underlying cause. Many studies seem to show that CVG occurs in individuals in a secondary form to other ailments. However, the condition can also be present on its own.
The classifications are:
*Primary*Primary essential*Primary non essential*Secondary Primary CVG is where the cause of the condition in unknown.Primary essential CVG has no other associated abnormalities. This occurs mainly in men, with a male:female ratio of 5 or 6:1, and develops during or soon after puberty. Because of the slow progression of the condition, which usually occurs without symptom, it often passes unnoticed in the early stage
Primary non essential CVG can be associated with neuropsychiatric disorders including cerebral palsy, epilepsy, seizures and ophthalmologic abnormalities, most commonly cataracts.
Secondary CVG occurs as a consequence of a number of diseases that produce changes in scalp structure. (These conditions include: Acromegaly (excessive growth hormone, due to pituitary gland tumour),Melanocytic naevi (moles), Birthmarks (including Connective tissue naevi, fibromas and naevus lipomatosus), Inflammatory processes (e.g., eczema, psoriasis, Darier disease, folliculitis, impetigo, atopic dermatitis, acne