Neuroimaging Findings in Fetal Hemimegalencephaly: Case Study and Review

BACKGROUND

Limited information exists in the prenatal literature regarding the neuroimaging features of fetal hemimegalencephaly.

SUMMARY

This report describes ultrasound and magnetic resonance imaging (MRI) findings in a second-trimester fetus with an isolated, severe form of hemimegalencephaly. The most prominent imaging findings included unilateral enlarged cerebral hemisphere and ipsilateral ventriculomegaly causing cerebral asymmetry, midline shift, and macrocephaly. Abnormal cortical development imaging signs were also evident. A literature review encompassing 23 reports describing 36 cases, including ours, is presented.

KEY MESSAGES

Characteristic ultrasound findings for the diagnosis of hemimegalencephaly are not always apparent prenatally. Asymmetric ventriculomegaly emerges as the most common but nonspecific presenting feature during routine second- or third-trimester ultrasound scans. Subsequent high-resolution prenatal neurosonography and fetal MRI facilitate definitive prenatal diagnosis, showcasting associated features primarily related to cortical migration, differentiation, and maturation. Postnatally, the prognosis is poor due to intractable seizures, hemiplegia, and progressive neurodevelopmental delay.

Morphometric analysis program: Detection of epileptic foci in young children using an adult normative database: Initial experience

Objective

To report our initial experience using an adult-template MAP in drug-resistant focal epilepsy in five children with apparently normal MRI.

Methods

Patients selected were highly suspicious of harboring focal structural lesions and had negative brain MRI studies. MAP was performed using a locally obtained adult database as a template. Results were reviewed by two neuroradiologists. Pertinence of MAP-positive areas was confirmed by the focal epileptic hypothesis or by pathology when possible (J Neuroradiol, 39, 2012, 87). Visual analysis was performed using Mango Software. MRI studies were reanalyzed at the workstation with knowledge of the clinical suspicion to confirm or discard the possibility of FCD.

Results

Five patients aged 19-48 months were studied, all with initial 3T MRI studies interpreted as normal. All had focal epileptic hypothesis with coherence of clinical seizure characterization and electroencephalographic findings. In two patients, histology showed type 1 FCD. Due to the age of our subjects, the junction map always highlighted the subcortical white matter in relationship to maturity differences. FCD was identified as asymmetric U-shaped highlighted regions in the junction map.

Significance

FCD is the most frequent pathology reported in pediatric epilepsy surgery series (Epileptic Disord, 18, 2016, 240). Significant number of FCDs may be overlooked on MRIs, reducing the odds of seizure freedom after surgery (Epilepsy Res, 89, 2010, 310). MAP is an image postprocessing method for enhanced visualization of FCD; however, when using an adult template in developing brains, normal subcortical regions may be highlighted as pathological. Creating a pediatric template is difficult, due to the need for general anesthesia to acquire the MRI database. Here, we were able to show that MAP identified FCDs as asymmetric "U-" shaped highlighted regions in the junction maps of all five patients, which may indicate that obtaining childhood databases for this purpose may not be necessary and that adult ones suffice for diagnosis of FCD.

A novel ITPA variant causes epileptic encephalopathy with multiple-organ dysfunction

Inborn errors of metabolism can cause epileptic encephalopathies. Biallelic loss-of-function variants in the ITPA gene, encoding inosine triphosphate pyrophosphatase (ITPase), have been reported in epileptic encephalopathies with lack of myelination of the posterior limb of the internal capsule, brainstem tracts, and tracts to the primary visual and motor cortices (MIM:616647). ITPase plays an important role in purine metabolism. In this study, we identified two novel homozygous ITPA variants, c.264-1 G > A and c.489-1 G > A, in two unrelated consanguineous families. The probands had epilepsy, microcephaly with characteristic magnetic resonance imaging findings (T2 hyperintensity signals in the pyramidal tracts of the internal capsule, delayed myelination, and thin corpus callosum), hypotonia, and developmental delay; both died in early infancy. Our report expands the knowledge of clinical consequences of biallelic ITPA variants.

[Pediatric intervertebral disc calcification: A rare cause of acquired torticollis. Case report]

INTRODUCTION

Pain and cervical muscle spasm are common reasons why parents bring children to the pediatric emergency department. The first steps are the gathering of medical history of the patient and a physical examination. If musculoskeletal damage is suspected, cervical spine x-rays should be obtained. An intervertebral disc calcification finding, in the absence of other radiological lesions should suggest pediatric intervertebral disc calcification.

OBJECTIVE

To present a case of intervertebral disc calcification, a rare condition that must be considered in the differential diagnosis of torticollis and neck pain in childhood.

CASE REPORT

A seven-year-old male patient without morbid history and no history of trauma or rough sport practice. He consulted the emergency room for pain and cervical contracture for the last six days. C reactive protein and red cell sedimentatio rates were slightly elevated. Imaging studies showed calcification of the C5-C6 intrvertebral disc and anterior disc protrusion. The patient was hospitalized for evaluation and pain management, with good clinical response and continue afterwards with non-steroidal anti-inflammatory drugs and a soft collar. At the 6-month-follow up, the patient had resolved symptoms and calcifications.

CONCLUSIONS

Pediatric intervertebral disc calcification is a rare cause of acquired torticollis, with a benign and self-limited outcome. Conservative management, as well as clinical and imaging follow-up is recommended.

Vigabatrin-induced MRI changes associated with extrapyramidal symptoms in a child with infantile spasms

Vigabatrin is an antiepileptic drug used for treatment of infantile spasms. We present a female patient with infantile spasms in treatment with vigabatrin who developed ataxic movements. MRI demonstrated a symmetrical pattern of thalamic and globi pallidi diffusion restriction. While these image features have been widely described to be related to the use of vigabatrin, this case highlights the development of movement disorders in association with MRI signal changes. Awareness of the reversible nature of this condition is reassuring for the treating team and avoids unjustified studies.

HIGH AMOUNT OF DINOPHYSISTOXIN-3 IN Mytilus chilensis COLLECTED IN SENO DE RELONCAVI, CHILE, DURING MASSIVE HUMAN INTOXICATION ASSOCIATED WITH OUTBREAK OF Vibrio parahaemolyticus

This study describes the detection of high amount of 7-O-acyl-derivative dinophysistoxin-1 (Dinophysistoxin-3) in filter bivalves collected on February 2005 in the Seno de Reloncaví, Puerto Montt City, Southern Chile, in the same period of time where an intoxication episode was associated with the presence of Vibrio parahaemolyticus in shellfish. The Diarrhetic Shellfish Poisoning (DSP) mouse bioassay of mussel extract samples, performed as described for regulatory testing, were negative to DSP toxins. Therefore, the same mussel samples collected from 8 places of Seno de Reloncaví were then analyzed by the HPLC-FLD method with pre-column derivatization procedure for DSP toxins. The samples showed mainly 7-O-acyl-derivative dinophysistoxin-1 (Dinophysistoxin-3) in concentrations ranging from 190.3 +/- 6.8 to 311.1 +/- 4.8 ng of DSP toxin/g hepatopancreas and less amounts of Dinophysistoxin-1 ranging from 1.9 +/- 1.5 to 11.7 +/- 4.6 ng of DSP toxin/g hepatopancreas. After alkaline hydrolysis of the mussel extracts, 279.4 +/- 7.2 ng of Dinophysistoxin-1 /g hepatopancreas (mean +/- SEM, N=6) were found in mussel extracts (Zone 8). These data showed that these shellfish samples are contaminated with the ester form 7-O-acyl-derivatives of Dinophysisyoxin-1, far beyond the safe regulatory limit. This paper also shows a direct relation between lipid content in the mussel tissue extracts and the levels of Dinophysistoxin-3. The 7-O-acyl-derivative dinophysistoxin-1 ester was the only compound associated with DSP toxins detected in the shellfish samples, and in view of the fact that metabolic transformation of Dinophysistoxin-3 into Dinophysistoxin-1 in humans has recently been described in the literature, the consumption of shellfish contaminated with 7-O-acyl-derivatives dinophysistoxin-1 could be a major reason that explains the diarrhetic symptoms shown by the intoxicated patients.