Bilateral hippocampal encephalitis caused by enteroviral infection.

Nonpolio enteroviral encephalitis usually presents as a diffuse, generalized encephalitis. Focal cerebral involvement by nonpolioviruses is uncommon, and neuroradiologic studies in these cases are usually normal. The authors present a case of a 5-year-old male with an acute encephalitic illness and bilateral lesions of the hippocampi on magnetic resonance imaging. Enteroviral nucleic acids were detected in the cerebrospinal fluid by the reverse transcription polymerase chain reaction. The findings suggest that enteroviral infection should be considered in the differential diagnosis of acute bilateral hippocampal encephalitis in patients in whom polymerase chain reaction fails to demonstrate the presence of herpes simplex virus.

Successful therapy in a child with a congenital peripheral medulloepithelioma and disruption of hindquarter development.

PURPOSE: Medulloepithelioma is an embryonal multipotential neuroepithelial tumor with a striking potential for divergent differentiation. It is usually intraocular or intracerebral and associated with a good prognosis only if completely surgically excised. Data regarding therapy in children with incompletely resected tumors are limited. PATIENT AND METHODS: A girl was born with a large, peripheral, congenital medulloepithelioma associated with complete absence of the left hindquarter and anus. Plain film, ultrasonography, and magnetic resonance imaging demonstrated complete absence of the left kidney and hemipelvis. A subtotal resection of the mass and reconstruction of the tumor-related anatomical defects were performed. RESULTS: Pathologic examination showed neuroglia and pseudostratified neuroectoderm diagnostic of medulloepithelioma. She was treated with multiagent chemotherapy including vincristine, cisplatin, cyclophosphamide, carboplatin, and etoposide. She is now 50 months of age and developing normally without recurrent disease. CONCLUSIONS: A child with an incompletely resected congenital peripheral medulloepithelioma who has experienced long-term disease-free survival after treatment with chemotherapy is described. This report supports a role for adjuvant chemotherapy in the treatment of children with peripheral medulloepithelioma.

Neuroimaging of postnatal pediatric central nervous system infections.

Pediatric neuroimaging plays an important role in the timely diagnosis of postnatal central nervous system (CNS) infections, and in some patients the imaging findings are sufficiently specific to suggest a cause. The sequela of CNS infection, including hydrocephalus, subdural collections, ischemia/infarction, cerebral abscess, demyelination, and vascular thrombosis, can be accurately depicted and serially followed with current imaging techniques. The purpose of this review is to describe the spectrum of pediatric postnatal CNS infections, emphasizing key pathological and neuroimaging features, and to outline the strengths, weaknesses, and applications of current neuroimaging technology. The prenatal and perinatal infections falling under the designation of TORCH (toxoplasmosis, other [e.g., syphilis, HIV], rubella, cytomegalovirus, and herpes simplex II) are not covered.

Choroid plexus papilloma and cysts in the Aicardi syndrome: case reports.

Two female infants with callosal agenesis, infantile spasms, chorioretinal lacunae, optic disc colobomas and cortical heterotopias were diagnosed with Aicardi syndrome. A choroid plexus papilloma was found in one patient, and choroid plexus cysts were found in the other. Choroid plexus lesions are common findings in the Aicardi syndrome and are discussed in this paper.

Factors associated with stroke following the Fontan procedure.

We reviewed the results of 68 consecutive Fontan procedures from 1978 to 1993 to determine the frequency of late central neurologic complications of the Fontan procedure in patients living at a mean altitude of 4500 feet. Two surviving patients had transient neurologic symptoms or signs with no corresponding evidence of brain injury by magnetic resonance imaging (MRI), whereas six surviving patients had strokes defined by sustained neurologic symptoms or signs with areas of brain injury identified by MRI [8.8% (6.0-13.0%; 70% confidence limits)]. Collectively, patients with neurologic symptoms had normal hemoglobin values, platelet counts, partial thromboplastin times, and prothrombin times at the onset of clinical neurologic findings. Two patients were taking antiplatelet agents, and one patient was taking warfarin. One of the patients with transient neurologic findings and all of the stroke patients had residual right-to-left shunts. Thus strokes were not uncommon in our patients after the Fontan procedure. Brain injury may result from thromboembolic events associated with residual right-to-left shunts, but our total number of asymptomatic patients with a residual shunt or brain abnormalities by MRI is not known.

Neuroimaging of premature infants.

Neuroimaging of babies born prematurely challenges each member of the imaging team. This article reviews the commonly used modalities for neuroimaging in premature infants (ultrasonography, CT, and MR imaging) and makes recommendations for their optimal implementation based on the imaging literature and the author's experience. Special care of the premature neonate in the imaging department is discussed. Suggestions are made for the proper application of current imaging technology to the frequently encountered problems of intracranial hemorrhage and periventricular leukomalacia in the neonate.

Pneumatization of the paranasal sinuses: normal features of importance to the accurate interpretation of CT scans and MR images.

CT and MR imaging of the paranasal sinuses in infants and children reveal a spectrum of findings associated with the normal pneumatization process, both inside the sinus cavities and in the adjacent marrow spaces. These normal findings must be understood and recognized so that CT scans and MR images may be accurately interpreted. If such normal developmental radiologic findings are not appreciated, misinterpretation may occur and lead to inappropriate treatment. In this pictorial essay, the normal process of pneumatization for each paranasal sinus group will be described from the first stages of the process to its completion. CT scans and MR images will illustrate the range of normal radiologic findings associated with the developmental process, with emphasis placed on the types of findings that, although normal, create potential interpretive difficulties.

Magnetic resonance angiography in pediatric neuroradiology.

Magnetic resonance angiography (MRA) is a novel technique that uses gradient echo pulse sequences and computer postprocessing technology to create vascular-flow images. The technique is easy to apply, noninvasive, and frequently yields information not available by other noninvasive means. The utility and benefits of MRA are amply documented by clinical studies in the neuroimaging literature. This article reviews the techniques of MRA and the current literature in the application of MRA in pediatric imaging. Illustrative cases demonstrating the use of MRA in pediatric neuroradiology are presented. The utilization of MRA in congenital lesions such as aberrant internal carotid artery and arteriovenous malformation and in differing causes of ischemic disease is highlighted. There is an ever-expanding number of applications of MRA in pediatric neuroimaging. Despite the lack of standardized protocols, with a thorough knowledge of the basic principles, MRA can be successfully applied in many imaging situations. The ease of use and noninvasive nature of MRA make it an ideal tool in the evaluation of the pediatric neurovasculature.

Cerebral MR angiography with multiple overlapping thin slab acquisition. Part II. Early clinical experience.

In a prospective, multicenter study of 164 patients, cerebral magnetic resonance (MR) angiography with multiple overlapping thin slab acquisition was evaluated for image quality and diagnostic accuracy. Of the 164 patients, 87 (53%) underwent either correlative cut-film angiography or surgery. The overall image quality was excellent in 90% of patient studies. Eighteen of 19 aneurysms were detected with MR angiography. The parent artery, the anatomy of the neck and dome, and the size were correctly shown in 17 of the 19 aneurysms. All 19 vascular malformations were seen with MR angiography. Venous malformations and single pedicle arteriovenous malformations were completely defined with MR angiography, while complete definition of complex arteriovenous malformations was frequently difficult. In cerebral tumors, the arteries and veins important in surgical planning were accurately shown in all cases. In ischemic cerebrovascular disease, MR angiography depicted all stenoses and occlusions of first- and second-order cerebral arteries. The inability to depict intraluminal filling defects in any but the large central arteries limited the ability of MR angiography to enable the specific diagnosis of embolic stroke.