Cutis verticis gyrata refers to a scalp condition characterized by the presence of convoluted folds and furrows resembling a cerebriform pattern. These patterns are formed by a process of hypertrophy and thickening of the skin. The primary nonessential form of the disease is usually associated with other pathologies, one of them being mental retardation. In its dermatological manifestation, this disease affects primarily the vertex and occipital region of the scalp. The folds themselves, numbering between 2-12, are soft and spongy, and run in an anterior to posterior direction. The folds have sparse hair, while the furrows may have normal hair growth.
Although exact incidence rates of this condition are not known, it has been reported that among people with mental retardation, 0.5% may be having cutis verticis gyrata. This condition is usually seen in males, with a male:female ratio of 5:1. This sexual discrepancy could be due to an endocrinological effect, or due to the fact that the longer hair of women may camouflage the condition. Brain imaging studies show subcutaneous fat, irregularly distributed cutaneous folds, severe abnormality of the occipital lobes, bilateral polymicrogyria, small frontal and anterior temporal lobes, parietal and occipital cortex atrophy, colpocephaly, hypoplastic splenium of the corpus callosum, and atrophy of the cerebellar cortex. A common complication of the disease is secondary infection of the furrows, leading to maceration and an unpleasant smell. Another complication is the potential for malignant transformation in about 10% of cases. Thus, patients identified with CVG need to be followed-up for a long time to detect the malignancy in time.
The genetic mechanism behind the pathogenesis of CVG/MR is not known. However, the preponderance of males has suggested an X-linked mode of inheritance.
Farah et al. (1998) described a patient with CVG/MR. Clinically, the patient exhibited mental retardation, drug-resistant epilepsy, a short stature, microcephaly, and multiple furrows on the scalp with normally growing overlying hair. The patient was blind with optic atrophy, and had multiple joint contractures and spastic tertraplegia. Brain MRI revealed small, but well-developed frontal and anterior temporal lobes, atrophic parietal and occipital cortex with colpocephaly, atrophic parietal opercula leading to accentuated sylvian fissures, and hypoplastic splenium of the corpus callosum. Most features of pachydermoperiostosis were absent. There was no evidence to suggest any migration disorder in this patient.