Neonatal Hemimegalencephaly Accompanying Band Heterotopia: Sonographic Finding and Correlation with MR Finding

There are many reports of hemimegalencephaly on MRI. However, there have been a few reports of sonographic diagnosis of the disease in a neonate. A one-day-old female infant was diagnosed as hemimegalencephaly accompanying band heterotopia on cranial sonography, which showed 4 a four-layered patterns of hypoechoic cortex, thick band-like hyperechoic subcortical white matter, inner hypoechoic heterotopia, and hyperechoic unmyelinated periventricular white matter. The sonographic patterns corresponded well with MRI findings on the second day of life. To the best of my knowledge, the author is the first to reports on the US findings and MR correlation of hemimegalencephaly.

A Novel Missense Mutation of Doublecortin: Mutation Analysis of Korean Patients with Subcortical Band Heterotopia

The neuronal migration disorders, X-linked lissencephaly syndrome (XLIS) and subcortical band heterotopia (SBH), also called "double cortex", have been linked to missense, nonsense, aberrant splicing, deletion, and insertion mutations in doublecortin (DCX) in families and sporadic cases. Most DCX mutations identified to date are located in two evolutionarily conserved domains. We performed mutation analysis of DCX in two Korean patients with SBH. The SBH patients had mild to moderate developmental delays, drug-resistant generalized seizures, and diffuse thick SBH upon brain MRI. Sequence analysis of the DCX coding region in Patient 1 revealed a c.386 C>T change in exon 3. The sequence variation results in a serine to leucine amino acid change at position 129 (S129L), which has not been found in other family members of Patient 1 or in a large panel of 120 control X-chromosomes. We report here a novel c.386 C>T mutation of DCX that is responsible for SBH.

A Case of Band Heterotopia with Lennox-Gastaut Syndrome / 대한소아신경학회지

Band heterotopia is a rare neuronal migration disorder, resulting in epilepsy and mental retardation. Epilepsy in band heteropopia, of which Lennox-Gastaut syndrome constituted about 20%, varied in nature and degree of severity. Band heterotopia can be diagnosed by brain magnetic resonance imaging (MRI), showing another diffuse layer of gray matter underlying the normal-looking cortex with intervening thin rim of white matter. While positron emission tomography (PET) with [18F]-fluorodeoxyglucose revealed glucose uptake similar to the overlying cortex, single photon emission computerized tomography (SPECT) findings of band heterotopia have not been reported. We report a 8-year-old girl who presented with variable types of generalized seizures and mild mental retardation. She was diagnosed as having band heterotopia with Lennox-Gastaut syndrome by MRI and interictal electroencephalogram (EEG) showing immature background and generalized 2 Hz slow spike and wave complexes. Interictal SPECT, using Tc 99m hexamethyl propylenamine oxime (Tc 99m-HMPAO), revealed the same degree of perfusion in both the areas of band heterotopia and the overlying cortex. By using valproate and lamotrigine, she is now in stable condition with a significant decrease in seizure frequency.

A Case of Band Heterotopia

The "band heterotopia" or "double cortex" is a brain anomaly that is presumed to result from a premature arrest of neuronal migration. Generalized disorders of neuronal migration to the cerebral cortex have been recognized since the end of the 19th century. Recently, development of neuroimaging technique, such as MRI, have permitted easy diagnosis of generalized neuronal migration disorder. This syndrome is prevalent in females. Most patients present with generalized or multifocal epilepsy, some mental retardation, pyramidal signs and in some dysarthria. Full scales I.Q.s ranging from severely low to normal have been reported. EEG investigations usually demonstrate generalized spike-and-wave discharges or multifocal EEG abnormalities. Classic MRI findings demonstrate a band of subcortical gray matter heterotopia underlying the cortical mantle and separated from it by a thin rim of white mater. We report a 3 year old girl who present a single episode of generalized tonic clonic seizure with fever. Her MRI showed characteristic findings of band heterotopia. She has not been showed further seizure attack. She is being follow up at OPD without medication.