Brain malformations in linear nevus sebaceous syndrome: an MR study

Cutaneous Manifestations and Neurological Diseases

Our skin and nervous system are tightly connected. Numerous dermatomes on our skin provide sensory information to the brain. Because skin changes can occasionally be the first sign of a neurological problem, understanding skin alterations is crucial as it can indicate early about the underlying condition, which can affect the prognosis of the disease. In these cases, the dermatologists' and neurologists' skills are complementary to each other. In this article, we have categorized diseases with neuro-cutaneous manifestations under different headings, such as infections, metabolic diseases, connective tissue disorders, genodermatoses, nutritional deficiency, and the diagnostic criteria of some commonly encountered diseases. Through tabulation, it has been observed that this categorization can serve as a useful reference for managing day-to-day patients who are either diagnosed with the diseases mentioned above or suspected to have the conditions.

Hemimegalencephalic variant of epidermal nevus syndrome: case report and literature review

The epidermal nevus syndrome (ENS) is an uncommon neurocutaneous disorder in which epidermal nevi are found in association with congenital abnormalities of the brain, eye, and/or skeleton. The association of epidermal nevi and neurologic abnormalities was comprehensively described by Schimmelpenning in 1957. Pavone et al. (1991) identified a homogeneous variant of ENS with hemimegalencephaly, gyral malformation, mental retardation, seizures and facial hemihypertrophy. A 13-year-old boy with the neurologic variant of ENS with hemimegalencephaly, facial asymmetry, febrile seizures and mental retardation is reported. Additionally, we performed a literature review using the search terms "epidermal nevus syndrome" and "hemimegalencephaly", including secondary sources of data such as reference lists of articles reviewed. We found 57 previously reported cases with the hemimegalencephalic variant of epidermal nevus syndrome, in which the most frequent associated features are severe epilepsy, in about half of cases with neonatal onset, mental retardation/developmental delay, ocular/visual involvement, and facial abnormalities.

Epibulbar complex choristoma and hemimegalencephaly in linear sebaceous naevus syndrome

Epidermal naevus syndrome is a group of congenital syndromes comprising epidermal naevi associated with a variety of developmental abnormalities of the ocular, nervous, skeletal, cardiovascular and urogenital systems. We describe a case of an 8-month-old boy with a brown alopecic plaque on his face and scalp and a vascularized epibulbar mass involving the entire cornea, which had been present since birth. Histopathological examination identified sebaceous naevus in combination with complex choristoma. Magnetic resonance imaging of the brain showed hemimegalencephaly.

Epidemiology of hemimegalencephaly: a case series and review

Hemimegalencephaly (HME) is a congenital brain malformation characterized by unilateral enlargement of the cerebral hemisphere. Clinically, HME is typically associated with hemiparesis, psychomotor retardation, and intractable seizures usually apparent soon after birth. HME is often an isolated finding, but it has been described as an occasional feature of a large number of syndromes, many of which may not be readily identified at birth. There are a multitude of case series and reports of HME in the English literature; however, there is no comprehensive, unbiased, detailed survey characterizing the proportion of cases of HME that are associated with a syndrome. We performed a retrospective study of all cases of HME seen at our institution from 1990 to 2003. Of the 15 cases of HME identified, 53% (8/15) were non-syndromic and 47% (7/15) of the cases were associated with a known or suspected genetic syndrome. In patients with syndromic HME, many of the syndromic features were not readily discernible at birth or in early infancy. It is, therefore, imperative to continually evaluate any infant with HME for signs and symptoms of these and other syndromes. Knowing the relative differential diagnosis will lead to a more comprehensive evaluation, improvement in expectant management, and appropriate counseling of families before considering radical surgical options such as hemispherectomy.

Neuroimaging in disorders of cortical development

Malformations of cortical development are important causes of developmental delay and epilepsy. They are classified by the presumed stage during which normal development is interrupted: neuronal proliferation and differentiation, neuronal migration, and late migration/cortical organization. This article discusses the important malformations in each of these groups, how and why the malformations develop, and their imaging findings. A better understanding of these disorders helps in genetic counseling of the parents and may help in the treatment of associated epilepsy.

Malformations of cortical development

Malformations of cortical development are an important cause of developmental delay and epilepsy. Proper identification of these malformations can greatly help in accurately counseling affected families and, in some cases, in the treatment of the epilepsy. Modem neuroimaging is an important tool in the diagnosis of these malformations.

Tc-99m HMPAO brain SPECT in linear nevus sebaceous syndrome

The authors present a case of linear nevus sebaceous syndrome (LNSS) with atrophy of bilateral frontotemporal areas of the brain, left cerebellum and hippocampus, and bilateral uncal dysplasia demonstrated by magnetic resonance imaging (MRI). Magnetic resonance angiography revealed bilateral internal carotid artery hypoplasia with absence of flow in the anterior and middle cerebral arteries. Tc-99m HMPAO brain SPECT demonstrated more areas of perfusion defects while MRI detected volume loss and gliosis in affected areas. Tc-99m HMPAO brain SPECT may be more useful for revealing absent or decreased perfusion areas of brain lesions than MRI in LNSS.

Proteus syndrome

This female Asian (Malay) baby had clinical features of Proteus syndrome. She had a large right facial lipolymphangioma with hyperpigmentation of the overlying skin. There was a smaller lymphangioma over the left side of her neck with excess nuchal folds, macrodactyly and bilateral talipes equinovarus. Despite the extensive hemifacial swelling, there was no evidence of upper respiratory tract obstruction. Generalized seizures developed on the sixth day of life which were controlled with phenobarbital. The lymphangiomas were excised without recurrence.

Hemimegalencephaly. Histological, immunohistochemical, ultrastructural and cytofluorimetric study of six patients

Hemimegalencephaly (HME) is an uncommon sporadic nonfamilial congenital dysplastic abnormality of the central nervous system, characterized by enlargement of one cerebral hemisphere, with cranial asymmetry, hemiparesis, epilepsy, and mental retardation. It can occur in isolation or associated with various anomalies, namely skin disorders. The main neuropathologic findings are hemispheric gigantism, macro- and/or micropolygyria, cortical thickening with lack of lamination, blurred boundaries of the gray and white matter, and large ortho- and heterotopic neural cells. The results obtained by morphological investigations carried out on six patients with HME, compared with the findings recorded in similar studies performed on one patient with tuberous sclerosis (TS) and another with pachygyria, allow the authors to (a) confirm the dysplastic nature of HME and its autonomy from TS; (b) demonstrate that ortho- and heterotopic neuronal cells do not differentiate completely during proliferation and migration from the germinal matrix; (c) document, by means of flow cytometric study, a normal euploid DNA content in the enlarged hemisphere, consequently ruling out heteroploidy as a cause of both cell "hypertrophy" and enlargement of the malformed cerebral hemisphere.

Neuroimaging of focal malformations of cortical development

Neuroimaging is playing an increasingly important role in the evaluation of patients with malformations of cerebral cortical development. In this review, the authors address optimal neuroimaging of cortical malformations using x-ray computed tomography, single-photon-emission computed tomography, positron emission tomography, magnetic resonance imaging, and magnetic resonance spectroscopy. Initially, the authors discuss the strengths and weaknesses of the various imaging techniques. This is followed by a discussion of the clinical and neuroimaging characteristics of several different imaging manifestations of focal malformations of cortical development, including polymicrogyria, focal subcortical heterotopia, schizencephaly, focally thickened gyri, focally irregular gyri, hemimegalencephaly, and transmural dysplasia. The authors intend that, after reading this review, the reader will have a better understanding of the optimal neuroimaging techniques for evaluating these malformations and their many neuroimaging appearances.

Linear sebaceous nevus syndrome (sebaceous nevus of Jadassohn) associated with abnormal neuronal migration and optic glioma: case report

A case of linear sebaceous nevus syndrome (sebaceous nevus of Jadassohn) in an infant is reported. The clinical manifestation and the radiological features of the central nervous system abnormalities associated with this neurocutaneous syndrome are presented. We believe that this is the first reported case of this syndrome in combination with optic glioma.

Epidermal nevus syndrome: subgroup with neuronal migration defects

Epidermal nevus syndrome is one of the sporadic congenital hamartoses in which neurologic abnormalities have been frequently reported. We report two cases with severe primary brain involvement, seizures, mental retardation, and facial hemihypertrophy. We emphasize the superiority of magnetic resonance imaging over other radiographic studies in outlining the primary central nervous system anomalies associated with this syndrome. Although attempts were made to distinguish between several variants of epidermal nevus syndrome, it is clear that these are one entity. Proteus syndrome, encephalocraniocutaneous lipomatosis, and epidermal nevus syndrome have several overlapping phenotypic features. We suggest that they represent a phenotypic continuum, which in turn suggests a common pathogenetic process. While the cause of these syndromes is unknown, observations point to a somatic mutation leading to variable patterns of mosaicism.

Disorders of the hair and scalp in children

A wide variety of disorders involving the scalp and hair exist that may be encountered in the pediatric and adolescent population. An approach to the differential diagnosis of many of these conditions can be considered once the patient is found to have either alopecia, scaling, or tumors of the scalp. Certainly other causes of scalp or hair disease exist but the more common disorders can be appropriately considered in this manner.

Linear nevus sebaceous syndrome: megalencephaly and heterotopic gray matter

A 3-month-old white male with linear nevus sebaceous syndrome (LNSS), facial deformities, brain malformations, and cortical blindness is presented. Facial deformities included left ear hypertrophy and a left-sided hamartomatous neck mass. Magnetic resonance imaging suggested that a central nervous system (CNS) abnormality, involving gray and white matter, should be linked with LNSS. Magnetic resonance imaging was more useful than computed tomography in demonstrating the full spectrum of CNS anomalies, including unilateral lissencephaly, a paucity of white matter, excessive and heterotopic gray matter, apparent left schizencephaly, and unilateral left colpocephaly (dilation of atrium and posterior horn of lateral ventricle). Postmortem examination revealed left hemisphere megalencephaly with a dilated posterior horn of the lateral ventricle. The impressive gray matter heterotopias likely were the source of the patient's seizures and perhaps the ultimate cause of death. Megalencephaly and other deviations of neuronal migration should be considered as a dramatic component of LNSS.

Focal pachygyria with unusual vascular anomaly

A case of focal pachygyria with an unusual vascular anomaly is reported. Preoperative magnetic resonance imaging demonstrated few and broad gyri, and an abnormally thickened cortex of the right frontal lobe. In addition, T2-weighted imaging showed a high intensity lesion beneath the thickened cortex. In the pachygyric cortex, the peripheral portions of the arteries were tortuous and irregularly dilated, and prominent deep medullary veins were found draining into the subependymal veins. Histological examination revealed a decreased number of neurons with no tendency towards lamination, and degenerative changes with gliosis in the white matter. These findings suggest that the etiology of this anomaly may be gradual perfusion failure restricted to the territory of the anomalous vessels through the period of neuronal migration to the post-migratory, perinatal stage.