Severe brain involvement in 5q spinal muscular atrophy type 0.

Spinal muscular atrophy (SMA) type 0 is the most severe form of SMA, associated with the SMN1 gene and manifesting at birth. Most patients die in the first weeks of life. In this work, we present 3 patients with SMA type 0 who survived >1 year and presented diffuse and progressive brain abnormalities on magnetic resonance imaging, which are not usually seen in patients with SMA. Thus, severe brain involvement may likely be the full end manifestation of an already extreme SMA phenotype caused by substantial reduction of the SMN protein in the brain. ANN NEUROL 2019;86:458-462.

Pediatric multiple sclerosis: from clinical basis to imaging spectrum and differential diagnosis.

Pediatric multiple sclerosis (MS) deserves special attention because of its impact on cognitive function and development. Although knowledge regarding pediatric MS has rapidly increased, understanding the peculiarities of this population remains crucial for disease management. There is limited expertise about the efficacy and safety of current disease-modifying agents. Although pathophysiology is not entirely understood, some risk factors and immunological features have been described and are discussed herein. While the revised International Pediatric MS Study Group diagnostic criteria have improved the accuracy of diagnosis, the recently revised McDonald criteria also offer some new insights into the pediatric population. It is fundamental that radiologists have strong knowledge about the vast spectrum of demyelinating disorders that can occur in childhood to ensure appropriate diagnosis and provide early treatment.

Thrombus Imaging Characteristics and Outcomes in Acute Ischemic Stroke Patients Undergoing Endovascular Treatment.

Background and Purpose- Thrombus imaging characteristics have been reported to be useful to predict functional outcome and reperfusion in acute ischemic stroke. However, conflicting data about this subject exist in patients undergoing endovascular treatment. Therefore, we aimed to evaluate whether thrombus imaging characteristics assessed on computed tomography are associated with outcomes in patients with acute ischemic stroke treated by endovascular treatment. Methods- The MR CLEAN (Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands) Registry is an ongoing, prospective, and observational study in all centers performing endovascular treatment in the Netherlands. We evaluated associations of thrombus imaging characteristics with the functional outcome (modified Rankin Scale at 90 days), mortality, reperfusion, duration of endovascular treatment, and symptomatic intracranial hemorrhage using univariable and multivariable regression models. Thrombus characteristics included location, clot burden score (CBS), length, relative and absolute attenuation, perviousness, and distance from the internal carotid artery terminus to the thrombus. All characteristics were assessed on thin-slice (≤2.5 mm) noncontrast computed tomography and computed tomography angiography, acquired within 30 minutes from each other. Results- In total, 408 patients were analyzed. Thrombus with distal location, higher CBS, and shorter length were associated with better functional outcome (adjusted common odds ratio, 3.3; 95% CI, 2.0-5.3 for distal M1 occlusion compared with internal carotid artery occlusion; adjusted common odds ratio, 1.15; 95% CI, 1.07-1.24 per CBS point; and adjusted common odds ratio, 0.96; 95% CI, 0.94-0.99 per mm, respectively) and reduced duration of endovascular procedure (adjusted coefficient B, -14.7; 95% CI, -24.2 to -5.1 for distal M1 occlusion compared with internal carotid artery occlusion; adjusted coefficient B, -8.5; 95% CI, -14.5 to -2.4 per CBS point; and adjusted coefficient B, 7.3; 95% CI, 2.9-11.8 per mm, respectively). Thrombus perviousness was associated with better functional outcome (adjusted common odds ratio, 1.01; 95% CI, 1.00-1.02 per Hounsfield units increase). Distal thrombi were associated with successful reperfusion (adjusted odds ratio, 2.6; 95% CI, 1.4-4.9 for proximal M1 occlusion compared with internal carotid artery occlusion). Conclusions- Distal location, higher CBS, and shorter length are associated with better functional outcome and faster endovascular procedure. Distal thrombus is strongly associated with successful reperfusion, and a pervious thrombus is associated with better functional outcome.

Imaging Patterns of Toxic and Metabolic Brain Disorders.

Toxic and metabolic brain disorders are relatively uncommon diseases that affect the central nervous system, but they are important to recognize as they can lead to catastrophic outcomes if not rapidly and properly managed. Imaging plays a key role in determining the most probable diagnosis, pointing to the next steps of investigation, and providing prognostic information. The majority of cases demonstrate bilateral and symmetric involvement of structures at imaging, affecting the deep gray nuclei, cortical gray matter, and/or periventricular white matter, and some cases show specific imaging manifestations. When an appropriate clinical situation suggests exogenous or endogenous toxic effects, the associated imaging pattern usually indicates a restricted group of diagnostic possibilities. Nonetheless, toxic and metabolic brain disorders in the literature are usually approached in the literature by starting with common causal agents and then reaching imaging abnormalities, frequently mixing many different possible manifestations. Conversely, this article proposes a systematic approach to address this group of diseases based on the most important imaging patterns encountered in clinical practice. Each pattern is suggestive of a most likely differential diagnosis, which more closely resembles real-world scenarios faced by radiologists. Basic pathophysiologic concepts regarding cerebral edemas and their relation to imaging are introduced-an important topic for overall understanding. The most important imaging patterns are presented, and the main differential diagnosis for each pattern is discussed. Online supplemental material is available for this article. ©RSNA, 2019.

Imaging of Creutzfeldt-Jakob Disease: Imaging Patterns and Their Differential Diagnosis.

Diagnosis of sporadic Creutzfeldt-Jakob disease (sCJD) remains a challenge because of the large variability of the clinical scenario, especially in its early stages, which may mimic several reversible or treatable disorders. The molecular basis of prion disease, as well as its brain propagation and the pathogenesis of the illness, have become better understood in recent decades. Several reports have listed recognizable clinical features and paraclinical tests to supplement the replicable diagnostic criteria in vivo. Nevertheless, we lack specific data about the differential diagnosis of CJD at imaging, mainly regarding those disorders evolving with similar clinical features (mimicking disorders). This review provides an update on the neuroimaging patterns of sCJD, emphasizing the relevance of magnetic resonance (MR) imaging, summarizing the clinical scenario and molecular basis of the disease, and highlighting clinical, genetic, and imaging correlations in different subtypes of prion diseases. A long list of differential diagnoses produces a comprehensive pictorial review, with the aim of enabling radiologists to identify typical and atypical patterns of sCJD. This review reinforces distinguishable imaging findings and confirms diffusion-weighted imaging (DWI) features as pivotal in the diagnostic workup of sCJD, as these findings enable radiologists to reliably recognize this rare but invariably lethal disease. A probable diagnosis is justified when expected MR imaging patterns are demonstrated and CJD-mimicking disorders are confidently ruled out. ©RSNA, 2017.

Diffusion tensor MR imaging in neurofibromatosis type 1: expanding the knowledge of microstructural brain abnormalities.

BACKGROUND: Neurofibromatosis type 1 (NF1) is a hereditary disease with a dominant autosomal pattern. In children and adolescents, it is frequently associated with the appearance of T2-weighted hyperintensities in the brain's white matter. MRI with diffusion tensor imaging (DTI) is used to detect white matter abnormalities by measuring fractional anisotropy (FA). OBJECTIVE: This study employed DTI to evaluate the relationship between FA patterns and the findings of T2 sequences, with the aim of improving our understanding of anatomical changes and microstructural brain abnormalities in individuals with NF1. MATERIALS AND METHODS: Forty-four individuals with NF1 and 20 control subjects were evaluated. The comparative analysis of FA between NF1 and control groups was based on four predetermined anatomical regions of the brain hemispheres (basal ganglia, cerebellum, pons, thalamus) and related the presence or absence of T2-weighted hyperintensities in the brain, which are called unidentified bright objects (UBOs). RESULTS: The FA values between the groups demonstrated statistically significant differences (P ≤ 0.05) for the cerebellum and thalamus in patients with NF1, independent of the occurrence of UBOs. CONCLUSIONS: Diffusion tensor MR imaging confirms the influence of UBOs in the decrease of FA values in this series of patients with NF1. Additionally, this technique allows the characterization of microstructural abnormalities even in some brain regions that appear normal in conventional MR sequences.

Cranial vault lymphoma: a systematic review of five patients.

Bone involvement is a common finding in many types of lymphoma (Clin Oncol 9(3): 195-196, 1997). However, cranial vault affliction has been regarded as an exceedingly rare presentation, particularly in the case of primary lymphoma (J Neurosurg 108(5): 1018-1020, 2008). Our objective is to describe a series of five immunocompetent patients with histologically confirmed cranial vault lymphoma (CVL), and to conduct a systematic review of the current literature. Our review points out identical imaging patterns in most of the lesions for all reported CVL cases, despite their different histological subtypes. This typical pattern can be seen on computed tomography (CT) scans and magnetic resonance imaging (MRI) as an expansive tumor that affects all three compartments of the cranial vault, including the scalp, skull bone, and pachymeninges, even in the absence of osteolysis. We argue that the absence of osteolysis might enhance diagnostic capability. In the appropriate clinical setting, these features represent important disease characteristics that may help with an earlier diagnosis. Large B-cell lymphoma was the most common subtype of primary CVL.

Association between brain morphology and electrophysiological features in Congenital Zika Virus Syndrome: A cross-sectional, observational study.

BACKGROUND: Intrauterine infection with the Zika virus (ZIKV) has been connected to severe brain malformations, microcephaly, and abnormal electrophysiological activity. METHODS: We describe the interictal electroencephalographic (EEG) recordings of 47 children born with ZIKV-derived microcephaly. EEGs were recorded in the first year of life and correlated with brain morphology. In 31 subjects, we tested the association between computed tomography (CT) findings and interictal epileptiform discharges (IED). In eighteen, CTs were used for correlating volumetric measurements of the brainstem, cerebellum, and prosencephalon with the rate of IED. FINDINGS: Twenty-nine out of 47 (62%) subjects were diagnosed as having epilepsy. Those subjects presented epileptiform discharges, including unilateral interictal spikes (26/29, 90%), bilateral synchronous and asynchronous interictal spikes (21/29, 72%), and hypsarrhythmia (12/29, 41%). Interestingly, 58% of subjects with clinical epilepsy were born with rhombencephalon malformations, while none of the subjects without epilepsy showed macroscopic abnormalities in this region. The presence of rhombencephalon malformation was associated with epilepsy (odds ratio of 34; 95% CI: 2 - 654). Also, the presence of IED was associated with smaller brain volumes. Age-corrected total brain volume was inversely correlated with the rate of IED during sleep. Finally, 11 of 44 (25%) subjects presented sleep spindles. We observed an odds ratio of 0·25 (95% CI: 0·06 - 1·04) for having sleep spindles given the IED presence. INTERPRETATION: The findings suggest that certain CT imaging features are associated with an increased likelihood of developing epilepsy, including higher rates of IED and impaired development of sleep spindles, in the first year of life of CZVS subjects. FUNDING: This work was supported by the Brazilian Federal Government through a postdoctoral fellowship for EBS (Talented Youth, Science without Borders), an undergraduate scholarship for AJR (Institutional Program of Science Initiation Scholarships, Federal University of Rio Grande do Norte, Brazil), by International Centre for Genetic Engineering and Biotechnology (CRP/BRA18-05_EC) and by CAPES (Grant number 440893/2016-0), and CNPq (Grant number 88881.130729/2016-01).

Cloning of cDNA sequences encoding cowpea (Vigna unguiculata) vicilins: Computational simulations suggest a binding mode of cowpea vicilins to chitin oligomers.

Vicilins are 7S globulins which constitute the major seed storage proteins in leguminous species. Variant vicilins showing differential binding affinities for chitin have been implicated in the resistance and susceptibility of cowpea to the bruchid Callosobruchus maculatus. These proteins are members of the cupin superfamily, which includes a wide variety of enzymes and non-catalytic seed storage proteins. The cupin fold does not share similarity with any known chitin-biding domain. Therefore, it is poorly understood how these storage proteins bind to chitin. In this work, partial cDNA sequences encoding ß-vignin, the major component of cowpea vicilins, were obtained from developing seeds. Three-dimensional molecular models of ß-vignin showed the characteristic cupin fold and computational simulations revealed that each vicilin trimer contained 3 chitin-binding sites. Interaction models showed that chito-oligosaccharides bound to ß-vignin were stabilized mainly by hydrogen bonds, a common structural feature of typical carbohydrate-binding proteins. Furthermore, many of the residues involved in the chitin-binding sites of ß-vignin are conserved in other 7S globulins. These results support previous experimental evidences on the ability of vicilin-like proteins from cowpea and other leguminous species to bind in vitro to chitin as well as in vivo to chitinous structures of larval C. maculatus midgut.

Differentiation of Parkinson's disease and progressive supranuclear palsy with magnetic resonance imaging: the first Brazilian experience.

BACKGROUND: The objective of this study is to differentiate PSP from Parkinson's disease through magnetic resonance imaging. METHODS: We included 14 consecutive patients with PD (9) or PSP (5). These measures included the third ventricle, midbrain diameter, quadrigeminal plate, brainstem volumetry, and interpeduncular angle. RESULTS: Patients with PSP presented enlargement of third ventricle (100% vs. 33%), lower midbrain diameter (mean 13.2 +/- 1.7 mm vs. 16.5 +/- 1.7 mm) and thinning of the quadrigeminal plate (mean 2.7 +/- 0.3 mm vs. 3.6 +/- 0.3 mm) in comparison with PD. CONCLUSIONS: Characteristic findings on MRI may help to differentiate PD from PSP.

Collateral blood vessels in acute ischemic stroke: a physiological window to predict future outcomes.

Collateral circulation is a physiologic pathway that protects the brain against ischemic injury and can potentially bypass the effect of a blocked artery, thereby influencing ischemic lesion size and growth. Several recent stroke trials have provided information about the role of collaterals in stroke pathophysiology, and collateral perfusion has been recognized to influence arterial recanalization, reperfusion, hemorrhagic transformation, and neurological outcomes after stroke. Our current aim is to summarize the anatomy and physiology of the collateral circulation and to present and discuss a comprehensible review of the related knowledge, particularly the effects of collateral circulation on the time course of ischemic injury and stroke severity, as well as imaging findings and therapeutic implications.

MR cerebral blood volume maps correlated with vascular endothelial growth factor expression and tumor grade in nonenhancing gliomas.

BACKGROUND AND PURPOSE: Relative cerebral blood volume (rCBV) measurements derived from perfusion-weighted imaging (PWI) may be useful to evaluate angiogenesis and preoperatively estimate the grade of a glioma. We hypothesized that rCBV is correlated with vascular endothelial growth factor (VEGF) expression as marker of the angiogenic stimulus in presumed supratentorial low-grade gliomas (LGGs). METHODS: From February 2001 to February 2004, we examined 20 adults (16 men, four women; mean age 36 years; range, 23-60 years) with suspected (nonenhancing) supratentorial LGG on conventional MR imaging. Preoperative MR imaging used a dynamic first-pass gadolinium-enhanced, spin-echo echo-planar PWI. In heterogeneous tumors, we performed stereotactic biopsy in the high-perfusion areas before surgical resection. Semiquantitative grading of VEGF immunoreactivity was applied. RESULTS: Nine patients had diffuse astrocytomas (World Health Organization grade II), and 11 had other LGG and anaplastic gliomas. In patients with heterogeneous tumors on PWI, the high-rCBV focus had areas of oligodendroglioma or anaplastic astrocytoma on stereotactic biopsy, whereas the surgical specimens were predominantly astrocytomas. Anaplastic gliomas had high rCBV ratios and positive VEGF immunoreactivity. Diffuse astrocytomas had negative VEGF expression and mean rCBV values significantly lower than those of the other two groups. Three diffuse astrocytomas had positive VEGF immunoreactivity and high rCBV values. CONCLUSION: Our results confirmed the correlation among rCBV measurements, VEGF expression, and histopathologic grade in nonenhancing gliomas. PWI may add useful data to the preoperative assessment of nonenhancing gliomas. Its contribution in predicting tumor behavior and patient prognosis remains to be determined.

Evidence of acute ischemic tissue change in transient global amnesia in magnetic resonance imaging: case report and literature review.

Transient global amnesia is a benign syndrome of sudden-onset alteration of behavior with temporary dysfunction of anterograde and recent retrograde memory. Its neural substrates remain uncertain. Possible causes include ischemia, migraine, and epilepsy. The authors report a case of a 62-year-old man with a transient attack of memory disturbance, suggestive of transient global amnesia, in which magnetic resonance imaging performed 48 hours after onset showed left mesial temporal lobe signal changes on diffusion-weighted imaging and fluid-attenuated inversion recovery images. The findings and a literature review lend further support to the ischemic pathogenesis of transient global amnesia as a possible etiology, and underscore the role of diffusion-weighted imaging in the diagnosis of this condition.

Detection of corticospinal tract compromise in amyotrophic lateral sclerosis with brain MR imaging: relevance of the T1-weighted spin-echo magnetization transfer contrast sequence.

BACKGROUND AND PURPOSE: Hyperintensity in the posterior limb of the internal capsule at T2-weighted MR imaging, consistent with corticospinal tract (CST) degeneration, is described in amyotrophic lateral sclerosis (ALS). However, the lack of specific tests or biological markers hinders confirmation of the diagnosis, especially in the early stages. We investigated the CST in ALS with MR imaging. METHODS: We examined 25 patients (14 men, 11 women; mean age, 49.1 years; range, 29-68 years) and 21 age- and sex-matched control subjects without upper motor neuron signs. According to the revised El Escorial criteria, 22 patients had definite ALS; two, probable ALS; and one, suspected ALS. Fluid-attenuated inversion recovery (FLAIR; TR/TE/TI, 11,000/140/2600) and T1-weighted spin-echo (SE)/magnetization transfer contrast-enhanced (MTC; TR/TE, 510/12) imaging was performed at 1 T. Two experienced neuroradiologists blinded to the patients' history independently evaluated the CST. RESULTS: T1-weighted SE MTC imaging allowed visualization of the CST in both patients and control subjects. T1-weighted SE MTC images showed hypointensity along the CST and bilateral subcortical regions of the precentral gyri in all control subjects and hyperintensity in 80% of patients with ALS (P < .05). FLAIR images showed hyperintensity in these areas in both groups, with no significant difference. CONCLUSION: T1-weighted SE MTC imaging is sensitive and accurate in depicting CST lesions in ALS, whereas FLAIR imaging is not. T1-weighted SE MTC imaging is useful in diagnosing ALS by showing hyperintense areas along the CST, which separates patients from control subjects. This sequence should be included in the workup of patients with weakness and pyramidal signs.

Noninvasive MR cisternography with fluid-attenuated inversion recovery and 100% supplemental O(2) in the evaluation of neurocysticercosis.

SUMMARY: We describe an MR protocol for the noninvasive imaging of the subarachnoid space, which we use in patients with suspected neurocysticercosis in this space. It consists of a fluid-attenuated inversion recovery sequence performed 5 minutes after the continuous inhalation of 100% O(2) with a resultant increase in the signal intensity of the CSF that leads to a greater conspicuity of cyst walls in relation to the cortex and the extraventricular CSF.

Reversal of parkinsonism and portosystemic encephalopathy following embolization of a congenital intrahepatic venous shunt: brain MR imaging and 1H spectroscopic findings.

Parkinsonism and portosystemic encephalopathy (PSE) are cerebral disorders associated with motor and neuropsychological dysfunctions that may occur in patients with chronic liver disease. We describe a patient with parkinsonism and neuroradiologic and 1H spectroscopic findings of PSE associated with a large congenital intrahepatic portosystemic venous shunt. Chronic liver disease was absent. After endovascular treatment, we documented a progressive reversal of parkinsonism and PSE on the basis of clinical, neuroradiologic, and spectroscopic criteria.

Relationship between the concentration of supplemental oxygen and signal intensity of CSF depicted by fluid-attenuated inversion recovery imaging.

BACKGROUND AND PURPOSE: Prior reports have described increased signal intensity (SI) of CSF on fluid-attenuated inversion recovery (FLAIR) images of anesthetized patients receiving 100% O(2). This appearance can simulate that of diseases. We evaluated the relationship between the concentration of inhaled O(2) and the development of increased SI of CSF on FLAIR images. METHODS: FLAIR was performed in 25 healthy volunteers breathing room air and 100% O(2) through a face mask for 5, 10, and 15 minutes. MR imaging, including FLAIR imaging, was performed in 52 patients with no potential meningeal abnormalities under general anesthesia: 21 received an equal mixture of N(2)O and O(2), and 31 received 100% O(2). The SI of CSF in volunteers and patients was graded in several locations by using a three-point scale. RESULTS: SI of CSF significantly increased (P <.05) in various locations, in both volunteers and patients breathing 100% O(2), when compared with SI in the same volunteers breathing room air. Hyperintensity of CSF was not significantly different in volunteers receiving 100% O(2) through a face mask compared with anesthetized patients receiving 100% O(2) through a laryngeal airway or an endotracheal tube. No significant increase in SI occurred in patients receiving 50% O(2), when compared with the SI of volunteers breathing room air. CONCLUSION: Supplemental oxygen at 100% is a main cause of artifactual CSF hyperintensity on FLAIR images, regardless of the anesthetic drug used. This artifact does not develop when 50% O(2) is administered.

Stereotactic biopsy guidance in adults with supratentorial nonenhancing gliomas: role of perfusion-weighted magnetic resonance imaging.

OBJECT: The. diagnosis of low-grade glioma (LGG) cannot be based exclusively on conventional magnetic resonance (MR) imaging studies, and target selection for stereotactic biopsy is a crucial issue given the high risk of sampling errors. The authors hypothesized that perfusion-weighted imaging could provide information on the microcirculation in presumed supratentorial LGGs. METHODS: All adult patients with suspected (nonenhancing) supratentorial LGGs on conventional MR imaging between February 2001 and February 2004 were included in this study. Preoperative MR imaging was performed using a dynamic first-pass gadopentate dimeglumine-enhanced spin echo-echo planar perfusion-weighted sequence, and the tumors' relative cerebral blood volume (rCBV) measurements were expressed in relation to the values observed in contralateral white matter. In patients with heterogeneous tumors a stereotactic biopsy was performed in the higher perfusion areas before resection. Among 21 patients (16 men and five women with a mean age of 36 years, range 23-60 years), 10 had diffuse astrocytomas (World Health Organization Grade II) and 11 had other LGGs and anaplastic gliomas. On perfusion-weighted images demonstrating heterogeneous tumors, areas of higher rCBV focus were found to be oligodendrogliomas or anaplastic astrocytomas on stereotactic biopsy; during tumor resection, however, specimens were characterized predominantly as astrocytomas. Diffuse astrocytomas were associated with significantly lower mean rCBV values compared with those in the other two lesion groups (p < 0.01). The rCBV ratio cutoff value that permitted better discrimination between diffuse astrocytomas and the other lesion groups was 1.2 (80% sensitivity and 100% specificity). CONCLUSIONS: Perfusion-weighted imaging is a feasible method of reducing the sampling error in the histopathological diagnosis of a presumed LGG, particularly by improving the selection of targets for stereotactic biopsy.

Fast acquisition sagittal T1 magnetic resonance imaging (FAST1-MRI): a new imaging approach for the diagnosis of growth hormone deficiency.

Routine magnetic resonance imaging (MRI) is an established standard method to investigate the etiology of pituitary insufficiency. Among the anatomic abnormalities usually observed, ectopic hyperintense signal on T1 sequence is the most frequently associated with pituitary dysfunction. We developed a new protocol (FAST1-MRI) which is able to detect anatomic hypothalamic-pituitary abnormalities with 100% concordance when compared to the routine MRI protocol. FAST1-MRI takes only 3.25 minutes, and is performed without contrast, sedation or anesthesia. We studied 17 controls and 31 patients with growth hormone (GH) deficiency (18/31 with abnormal MRI). Patients with ectopic hyperintense signal were shorter in height, had lower IGF-I and IGFBP-3 levels, and reduced GH response after clonidine. In conclusion, we describe a new simplified MRI protocol that we propose should be used in the diagnosis of GH deficiency.