Macrocerebellum, epilepsy, intellectual disability, and gut malrotation in a child with a 16q24.1-q24.2 contiguous gene deletion.

Macrocerebellum is a rare condition characterized by enlargement of the cerebellum with conservation of the overall shape and cytoarchitecture. Here, we report on a child with a distinctive constellation of clinical features including macrocerebellum, epilepsy, apparent intellectual disability, dysautonomia, gut malrotation, and poor gut motility. Oligonucleotide chromosome microarray analysis identified a 16q24.1-q24.2 deletion that included four OMIM genes (FBXO31, MAP1LC3B, JPH3, and SLC7A5). Review of prior studies describing individuals with similar or overlapping16q24.1-q24.2 deletions identified no other reports of macrocerebellum. These observations highlight a potential genetic cause of this rare disorder and raise the possibility that one or more gene(s) in the 16q24.1-q24.2 interval regulate cerebellar development.

Dural puncture-induced intracranial hypotension causing diplopia.

BACKGROUND: Diplopia that occurs after an epidural spinal catheter has been placed for pain control has been attributed to sixth nerve palsy nerve palsy induced by intracranial hypotension. There is sparse information about the factors that confound diagnosis in this setting. METHODS: Review of 6 cases examined over a period of 5 years at a single tertiary care medical center. RESULTS: Six confounders to diagnosis were identified: 1) lack of awareness that an epidural spinal catheter was or had been in place; 2) delayed reporting of diplopia; 3) mild or inapparent ductional deficits; 4) lack of postural headache; 5) clinical features that suggested an alternative diagnosis; 6) neuroimaging features that did not allow exclusion of pachymeningitis. CONCLUSION: Clinicians should be aware of features that confound a diagnosis of dural puncture-induced intracranial hypotension as a cause of diplopia in the post-operative period when an epidural pain control system is or has been deployed. If these confounders are recognized and the correct diagnosis is reached, radiologists will be less likely to diagnose pachymeningitis and clinicians will be able to avoid lumbar puncture, which may exacerbate the condition.

Relapsing dorsal midbrain syndrome following interventions for hydrocephalus in aqueductal stenosis.

Dorsal midbrain syndrome (DMS) is a recognized clinical manifestation of increased intracranial pressure (ICP) associated with ventricular enlargement, especially in shunt malfunction, but the mechanism by which DMS occurs in this setting is unsettled. We report a patient with triventriculomegaly attributed to aqueductal narrowing by a tectal mass who went through 2 cycles of developing and resolving DMS promptly after undergoing interventions that altered the size of the posterior third ventricle and proximal aqueduct but probably did not markedly alter ICP. This case provides additional evidence that DMS in this setting is caused by deformation of the dorsal midbrain region produced by rapid expansion of the posterior third ventricle or proximal aqueduct.

Homonymous hemianopia from infarction of the optic tract and lateral geniculate nucleus in deep cerebral venous thrombosis.

A 20-year-old man developed right homonymous hemianopia, hemiparesis, and hemisensory loss from deep cerebral venous thrombosis in the setting of high altitude. Approximately 3 months later, brain MRI showed encephalomalacia of the left optic tract and lateral geniculate nucleus, as well as signal abnormalities of the internal capsule and posterolateral thalamus. Homonymous hemianopia has previously been described in 1 case after deep cerebral venous thrombosis but without detailed neuroimaging features.

Sixth cranial nerve palsy and ipsilateral trigeminal neuralgia caused by vertebrobasilar dolichoectasia.

PURPOSE: To report an unusual case of vertebrobasilar dolichoectasia causing both trigeminal neuralgia and ipsilateral sixth cranial nerve palsy. OBSERVATIONS: A patient had undergone surgical decompression of trigeminal neuralgia caused by dolichoectatic vertebral and basilar arteries years before presenting with ipsilateral sixth nerve palsy. Brain MRI showed deviant vertebrobasilar arteries that presumably now compressed the sixth cranial nerve. The unaffected left sixth cranial nerve was visible on MRI, but the affected right sixth cranial nerve was not. The central spinal fluid space in Dorello's canal on the affected side was relatively ample, suggesting atrophy of the affected sixth cranial nerve. On follow-up examination one year after presentation, the patient's diplopia was palliated with spectacle prism. CONCLUSIONS AND IMPORTANCE: This is the tenth reported case of dolichoectasia causing sixth cranial nerve palsy, but only the second to occur with dolichoectatic trigeminal neuralgia. It provides more detailed imaging that previously reported cases. Review of reported cases of dolichoectatic compression of cranial nerves indicates that vascular decompression may be effective for trigeminal neuralgia, but is not indicated for dolichoectatic sixth nerve palsy, which will resolve spontaneously or can be effectively managed with prism or eye muscle surgery.

Magnetic resonance imaging of oropharyngeal cancer.

Magnetic resonance imaging (MRI) is a powerful tool for cross-sectional analysis of head and neck anatomy and pathology. This is especially true with regard to oropharyngeal neoplasms, where soft tissue spread, nodal disease, perineural extension, and osseous involvement may significantly alter therapy and prognosis. In this article, we will provide a background on oropharyngeal cancers and MRI techniques and strategies, describing potential advantages of MRI with regard to particular anatomic subsites of the oropharynx. Future imaging trends in perfusion and diffusion MRI of such cancers are also discussed.

Alternatives to GBCA: Are We There Yet?

Gadolinium has been widely used as the contrast agent of choice for magnetic resonance imaging (MRI). However, gadolinium administration is not always desired due to its inherent enhancement properties and potential side effects (nephrogenic systemic fibrosis). This article reviews gadolinium alternatives, iron-, and manganese- based agents, and their current clinical usage for contrast-enhanced MRI examinations.

CT: history, technology, and clinical aspects.

The introduction of computerized tomography (CT) revolutionized noninvasive imaging, particularly with regards to the central nervous system. Further advances in CT technology over the past two decades have allowed for more elegant visualization of various bodily structures, including vascular anatomy and organ perfusion physiology. This article will review the development of computerized tomography from conventional machines to multislice helical units, emphasizing relevant advances in stroke imaging and including some discussion of radiation safety.

Neck MR imaging anatomy.

The normal MR imaging appearance of the neck can be confusing given the number and complexity of structures that pass through it. This article strives to simplify normal MR imaging anatomy of the neck using a spatial approach. We present the protocols used at our institution and provide tables with details. Magnetic resonance (MR) imaging anatomy and appearance of the deep spaces of the neck are described with extensive labeled imaging correlates. Pearls and common pitfalls encountered with MR imaging of the neck are discussed. Additional aspects of normal neck MR imaging are described including lymph node, brachial plexus, and vascular anatomy.

Skull base, orbits, temporal bone, and cranial nerves: anatomy on MR imaging.

Accurate delineation, diagnosis, and treatment planning of skull base lesions require knowledge of the complex anatomy of the skull base. Because the skull base cannot be directly evaluated, imaging is critical for the diagnosis and management of skull base diseases. Although computed tomography (CT) is excellent for outlining the bony detail, magnetic resonance (MR) imaging provides better soft tissue detail and is helpful for evaluating the adjacent meninges, brain parenchyma, and bone marrow of the skull base. Thus, CT and MR imaging are often used together for evaluating skull base lesions. This article focuses on the radiologic anatomy of the skull base pertinent to MR imaging evaluation.

Cross-sectional examination interpretation discrepancies between on-call diagnostic radiology residents and subspecialty faculty radiologists: analysis by imaging modality and subspecialty.

PURPOSE: The aim of this study was to identify the rate of discrepancies between radiology residents and faculty radiologists at an academic hospital and to determine the distribution across subspecialties and modalities, specifically CT, MR, and ultrasound. METHODS: Consecutive CT, MR, and ultrasound preliminary interpretations rendered by on-call second-year through fourth-year radiology residents for 9 months on emergency department patients, inpatients, and urgent outpatients formed the study population. All preliminary interpretations were graded using a modified RADPEER(®) system (scores 0 and 1 = concordance; score 2 = minor, clinically insignificant discordance; scores 3 and 4 = clinically significant discordance) by the subspecialty faculty members who rendered the final interpretation. RESULTS: There were 158 clinically significant discrepancies out of 21,482 preliminary interpretations, for a discrepancy rate of 0.7%. There was no statistically significant difference in rates across subspecialties or between adult and pediatric examinations (cardiothoracic, 1%; abdominal, 0.7%; neuroradiology, 0.6%; musculoskeletal, 0.7%; pediatrics, 0.8%). MR and CT interpretations had significantly higher rates than ultrasound (MR, 1.4%; CT, 0.9%; ultrasound, 0.2%; P < .001). Within neuroradiology, there was a significantly higher rate for MR than CT (1.5% vs 0.6%, P < .01), and within abdominal radiology, there was a significantly higher rate for CT than ultrasound (1.1% vs 0.2%, P < .01). CONCLUSIONS: Discrepancy rates in this study were less than or comparable with those reported previously and within or lower than rates for practicing radiologists. Discrepancy rates varied among subspecialties and modalities, suggesting the use of a RADPEER system with attention to modality and subspecialty as a methodology for identifying areas for targeted resident education.

Prevalence and etiology of intracranial hemorrhage in term children under the age of two years: a retrospective study of computerized tomographic imaging and clinical outcome in 798 children.

RATIONALE AND OBJECTIVES: The purposes of this study were to retrospectively identify various etiologies underlying intracranial hemorrhages (ICHs) in term infants aged <2 years and their respective prevalence in this population and to describe the long-term clinical outcomes in these patients. MATERIALS AND METHODS: A retrospective review of the medical records and computed tomographic studies of the head in 798 term infants aged 0 to 24 months with suspected or known ICHs was conducted. RESULTS: ICHs were present in 195 of the 798 infants (24%). More than one type of ICH was present in 32%. Subdural hemorrhage was the most frequent type of ICH, occurring in 63% of the infants. Good clinical outcomes were present in 49% of the infants but varied depending on the location, etiology, and timing of the ICH. CONCLUSION: The incidence of various etiologies of ICH depended on the ages of the infants. The overall clinical outcomes were good, with no long-term sequelae in half of the infants presenting with ICHs. In infants aged >4 weeks presenting with ICHs, special attention should be given to the possibility of nonaccidental trauma etiology, because this is common and has worse long-term outcomes.