Regional cortical dysplasia associated with suspected hypomelanosis of Ito

Neuropsychological and Social Characteristics of a 7 Year Old Child with Hypomelanosis of Ito Followed for 11 Years

Hypomelanosis of Ito (HI) is a neurocutaneous disorder associated with central nervous system abnormalities, including speech delay and intellectual disability. The long term neuropsychological and social characteristics of these children are unknown. Neuropsychological observations and parental reports were obtained yearly on a child with HI from ages 7 to 18 years. Serial measures of intelligence revealed stable verbal and perceptual reasoning scores with later improvements in working memory and processing speed performance. Speech articulation improved at age 12, as did the speed of right-hand finger tapping. Improved social integration occurred, but anxiety persisted throughout this developmental period.

Hypomelanosis of Ito: a round on the frequency and type of epileptic complications

There is an ample evidence that hypopigmentation of the skin along the Blaschko's lines is frequently associated with neurological disorders. Nowadays, the term "Hypomelanosis of Ito" (HI) is applied when, together with the cutaneous lesions, various and multisystem organs are involved. Among these, the most frequent are cerebral manifestations, such as cognitive delay and epileptic seizures. For this reason, hypomelanosis of Ito has been included in the group of neurocutaneous syndromes, neurologic manifestations being one of the most frequent. Epileptic seizures have been reported in patients with this disorder, but in a very few particular attention has been focused on the type and frequency of epilepsy and on the response to the treatment. Herein, we report on five patients with HI who showed episodes of epileptic seizures with onset in childhood, in absence of malformative anomalies except for the skin lesions. A survey on the frequency and types of epileptic seizures in HI children and in the literature is reported.

Neuropathology of pediatric epilepsy

The preoperative study of patients who are candidates for epilepsy surgery often classifies their epileptic foci as "lesional" or "non-lesional" based upon evidence from neuroimaging. Many lesions not detected by MRI are found by microscopic examination of the resected tissue. Advances have been made in neuropathological techniques to study resected brain tissue and to specify the types of focal cortical dysgeneses and other lesions by extending microscopic findings by applying immunocytochemical markers that identify specific types and distributions of neurons and glial cells that denote tissue architecture. There may be etiological differences between focal and extensive cortical dysplasias involving many gyri or entire lobes of cerebral cortex. Of additional importance in pediatric brain resections is that these modern techniques also denote cellular maturation and can identify abnormal cells with mixed lineage. α-B-crystallin can serve as a metabolic tissue marker of epileptic activity, regardless of the presence or absence of a "structural" lesion by MRI or by conventional histopathology. Satellitosis may contribute to epileptogenic neurons and later to death of those neurons. The classification of malformations of the brain is a process requiring continuous updates that include genetics, neuroimaging, and neuropathology as new data emerge, but should not be exclusive to one region of the brain, such as cerebral cortex or cerebellum. Standardization in neuropathological terminology enhances scientific communication. The ILAE recently published a useful consensus classification of focal cortical dysplasias that is flexible to enable future revisions and changes as new data become available.

New association between ring chromosome 20 syndrome and hypomelanosis of Ito

Hypomelanosis of Ito is an uncommon neuroectodermal disease associated with a wide range of cytogenetic abnormalities. Ring chromosome 20 is a rare chromosomal disorder characterized by severe, refractory epilepsy, cognitive delay, and unspecific dysmorphic traits. An association between the hypomelanosis of Ito and ring chromosome 20 syndrome was never reported peviously. We describe a young girl who has ring chromosome 20 and who also has clinical symptoms of hypomelanosis of Ito. After her diagnosis of epilepsy, she was submitted to neurologic and genetic testing, a skin biopsy, and repeated neuropsychologic examinations. Karyotyping revealed a 46 XX, r(20) with mosaicism in 34% of peripheral blood lymphocytes and 8% of skin fibroblasts. A severe, progressive cognitive deterioration was evident. The epilepsy was refractory to antiepileptic drugs, in apparent contrast with the evidence that both telomeric regions were preserved. The percentage of mosaicism seems unrelated to the severity of the clinical phenotype.

Heterogeneous seizure manifestations in Hypomelanosis of Ito: report of four new cases and review of the literature

Hypomelanosis of Ito (HI) is a rare neuroectodermal disorder often associated with mental retardation and epilepsy. We report on four new HI patients presenting with heterogeneous seizure manifestations and we review the literature concerning epileptic seizures in HI. At one extreme, there are patients with generalized seizures well controlled by drug treatment, whereas at the opposite there are patients with severe, often pharmacoresistant, focal seizures. The genetic substrate for HI syndrome is not homogenous and only partially understood. Further researches are required to shed light on the pathogenesis of HI phenotypes.

Epilepsy surgery for the neurocutaneous disorders

Patients with neurophakomatoses were not always considered to be candidates for surgical resection of epileptogenic foci, given the multifocal nature of their disease. Advances in imaging, monitoring, and surgical technique have allowed the identification of particularly active areas of cortex that may provide these patients with better seizure control than medications alone. Options for surgical resection range from focal resections (in those with localized disease) to hemispherectomies (in those with hemispheric involvement).

Hypomelanosis of Ito associated with precocious puberty

Hypomelanosis of Ito has been associated with precocious puberty in two cases. This study reports a third case involving a female with hypomelanosis of Ito including severe mental retardation and seizure disorder with autonomic symptoms (gastroesophageal reflux and asthma). At age 5 she developed vaginal discharge, thelarche, and adrenarche. Soon after, she died of pneumonia stemming from her neurologic deficits. A postmortem examination revealed normal gonads and endocrine organs. The breasts and vulva were prematurely developed. Central nervous system findings included megalencephaly, neuronal eosinophilic inclusions, leptomeningeal neuroglial heterotopias, and cortical dysplasia. Both previously reported cases of hypomelanosis of Ito associated with precocious puberty had abnormal gonads and responded to cyproterone acetate therapy, indicating a peripheral mechanism of precocious puberty (gonadotrophin-independent). The current case, which was autopsied, lacks significant gonadal pathology, and has extensive neurologic involvement that suggests that a central mechanism of precocious puberty (gonadotrophin-dependent) can also be associated with hypomelanosis of Ito.

Preoperative clinical evaluation and noninvasive electroencephalogram in cortical dysplasia

The preoperative evaluation of patients with suspected cortical dysplasia involves detailed neurologic and neuropsychologic evaluations, electroencephalography, and comprehensive neuroimaging and functional studies. The goal is to identify a focal region of seizure onset and to assess for motor impairments, speech and language difficulties, or developmental delay. Although the electroencephalogram abnormalities in cortical dysplasia are nonspecific, they typically include unusual high-amplitude (slowing and focal) activity. The association of cortical dysplasia with cardiovascular, dermatologic, and other systemic disorders is discussed.