Neuroradiologic Phenotyping of Galactosemia: From the Neonatal Form to the Chronic Stage.

Galactosemia is a rare genetic condition caused by mutation of enzymes involved in galactose and glucose metabolism. The varying clinical spectrum reflects the genetic complexity of this entity manifesting as acute neonatal toxicity syndrome, requiring prompt diagnosis and treatment, to more insidious clinical scenarios as observed in the subacute and chronic presentations. The current literature predominantly focuses on the long-standing sequelae of this disease. The purpose of this multicenter clinical report comprising 17 patients with galactosemia is to highlight the MR imaging patterns encompassing the whole spectrum of galactosemia, emphasizing the 3 main clinical subtypes: 1) acute neonatal presentation, with predominant white matter edema; 2) subacute clinical onset with a new finding called the "double cap sign"; and 3) a chronic phase of the disease with heterogeneous imaging findings. The knowledge of these different patterns together with MR spectroscopy and the clinical presentation may help in prioritizing galactosemia over other neonatal metabolic diseases and prevent possible complications.

Impact of Skull Defects on the Role of CTA for Brain Death Confirmation.

BACKGROUND AND PURPOSE: Intracranial pressure modifications caused by a skull defect, such as craniectomy or craniotomy, may change the hemodynamics and decrease the accuracy of CTA to confirm brain death. This study aimed to evaluate the impact of a skull defect and the interpretation criteria of images on this diagnostic test. MATERIALS AND METHODS: A series of consecutive patients with a clinical diagnosis of brain death underwent CTA (case group), while the control group comprised patients with acute ischemic stroke in the same period. CTA criteria adopted to confirm brain death were the absence of opacification of the M4 branches and internal cerebral veins. The evaluation also included the presence of "stasis filling." Cases were stratified as intact skull, craniotomy, and craniectomy. Three neuroradiologists evaluated all examinations independently. RESULTS: In the case group, according to the Frampas criteria, the sensitivity of CTA to confirm brain death was 95.5% in patients with intact skull, 87.5% with craniotomy, and 60% with craniectomy. False-negative diagnoses of brain death were 15.6%, related to stasis filling in 71.4% (P < .001). However, according to the "modified Frampas criteria," the sensitivity of CTA to confirm brain death was 100% in patients with intact skull, 93.8% with craniotomy, and 80% with craniectomy. False-negative diagnoses of brain death were found in 6.2% of patients, and there was no stasis filling. CTA showed 100% specificity in the control group. There were no disagreements among observers. CONCLUSIONS: CTA had a high diagnostic accuracy and reproducibility to confirm brain death in patients with an intact skull. The modified Frampas criteria increased the sensitivity of CTA, particularly in patients with a skull defect. A concurrent skull defect, especially craniectomy, can decrease the sensitivity of CTA to confirm brain death.

Gadolinium-Enhanced Susceptibility-Weighted Imaging in Multiple Sclerosis: Optimizing the Recognition of Active Plaques for Different MR Imaging Sequences.

BACKGROUND AND PURPOSE: Gadolinium SWI is MR imaging that has recently been reported to be effective in the evaluation of several neurologic disorders, including demyelinating diseases. Our aim was to analyze the accuracy of gadolinium SWI for detecting the imaging evidence of active inflammation on MS plaques when a BBB dysfunction is demonstrated by a focal gadolinium-enhanced lesion and to compare this technique with gadolinium-enhanced T1 spin-echo and T1 spin-echo with magnetization transfer contrast. MATERIALS AND METHODS: MR imaging studies of 103 patients (170 examinations) were performed using a 1.5T scanner. Two neuroradiologists scrutinized signal abnormalities of the demyelinating plaques on gadolinium SWI and compared them with gadolinium T1 before and after an additional magnetization transfer pulse. Interrater agreement was evaluated among gadolinium T1 magnetization transfer contrast, gadolinium SWI, and gadolinium T1 spin-echo using the κ coefficient. The T1 magnetization transfer contrast sequence was adopted as the criterion standard in this cohort. Thus, the sensitivity, specificity, positive predictive value, and negative predictive value were calculated for gadolinium T1 spin-echo and gadolinium SWI sequences. RESULTS: Differences in BBB dysfunction were evident among gadolinium SWI, gadolinium T1 spin-echo, and gadolinium T1 magnetization transfer contrast. Gadolinium T1 magnetization transfer contrast demonstrated the highest number of active demyelinating plaques. Gadolinium SWI was highly correlated with gadolinium T1 magnetization transfer contrast in depicting acute demyelinating plaques (κ coefficient = 0.860; sensitivity = 0.837), and these techniques provided better performance compared with gadolinium T1 spin-echo (κ coefficient = 0.78; sensitivity = 0.645). CONCLUSIONS: Gadolinium SWI was able to better detect BBB dysfunction in MS plaques and had a better performance than gadolinium T1 spin-echo. Increasing SWI sequence applications in clinical practice can improve our knowledge of MS, likely allowing the addition of BBB dysfunction analysis to the striking findings of the previously reported central vein sign.

Multinodular and Vacuolating Neuronal Tumor of the Cerebrum: A New "Leave Me Alone" Lesion with a Characteristic Imaging Pattern.

Multinodular and vacuolating neuronal tumor of the cerebrum is a recently reported benign, mixed glial neuronal lesion that is included in the 2016 updated World Health Organization classification of brain neoplasms as a unique cytoarchitectural pattern of gangliocytoma. We report 33 cases of presumed multinodular and vacuolating neuronal tumor of the cerebrum that exhibit a remarkably similar pattern of imaging findings consisting of a subcortical cluster of nodular lesions located on the inner surface of an otherwise normal-appearing cortex, principally within the deep cortical ribbon and superficial subcortical white matter, which is hyperintense on FLAIR. Only 4 of our cases are biopsy-proven because most were asymptomatic and incidentally discovered. The remaining were followed for a minimum of 24 months (mean, 3 years) without interval change. We demonstrate that these are benign, nonaggressive lesions that do not require biopsy in asymptomatic patients and behave more like a malformative process than a true neoplasm.

Recognizing Autoimmune-Mediated Encephalitis in the Differential Diagnosis of Limbic Disorders.

Limbic encephalitis is far more common than previously thought. It is not always associated with cancer, and it is potentially treatable. Autoantibodies against various neuronal cell antigens may arise independently or in association with cancer and cause autoimmune damage to the limbic system. Neuroimaging plays a key role in the management of patients with suspected limbic encephalitis by supporting diagnosis and excluding differential possibilities. This article describes the main types of autoimmune limbic encephalitis and its mimic disorders, and emphasizes their major imaging features.

A case review of the MRI features in alternating Tolosa-Hunt syndrome.

Tolosa-Hunt syndrome (THS) consists of a painful ophthalmoplegia with typical features in magnetic resonance imaging (MRI). The recurring nature of this affliction has been known since its first description. However, compromise of the contralateral cavernous sinus, known as alternating THS, is very rare and has never been examined using MRI. We report clinical data, laboratory data and imaging features of a patient with alternating THS. According to our literature review, this is the first MRI study of THS.

Hippocampal abnormalities in an MR imaging series of patients with tuberous sclerosis.

BACKGROUND AND PURPOSE: Hippocampal abnormalities are known as highly epileptogenic precursor lesions in the general population, primarily manifesting as MTS. The purpose of this study was to evaluate the occurrence of hippocampal abnormalities on MR imaging in patients with TS to explore the possible underlying mechanisms of the abnormalities and to identify the relationship between an abnormal HF and epilepsy. MATERIALS AND METHODS: We studied MR images and clinical data from 31 patients with TS. The MR imaging protocol was identical for all patients and included tilted coronal images of their temporal lobes. The diagnosis of TSC was made according to established criteria. The HFs of the patients were evaluated from coronal images according to size, morphology, and signal intensity. The data were submitted to statistical analysis, and P values < or = .05 were considered significant. RESULTS: We found HF abnormalities in 5 patients. Four had typical MTS, and 1 had HIMAL. We found a positive correlation between childhood febrile seizures and MTS in patients with TS. We also confirmed that patients with altered hippocampi had a tendency to exhibit more cortical tubers. CONCLUSIONS: Analysis of this series of patients demonstrated the presence of HF abnormalities, mainly MTS in patients with TS. We also found that the occurrence of febrile seizures during the first year of life appears to be one of the determining factors for MTS development in these patients.

A preliminary study revealing a new association in patients undergoing maintenance hemodialysis: manganism symptoms and T1 hyperintense changes in the basal ganglia.

BACKGROUND AND PURPOSE: Patients undergoing parenteral nutrition and those with portosystemic encephalopathy secondary to chronic liver disease and acquired and congenital portosystemic venous shunts frequently present manganese deposition in the basal ganglia, detected by MR imaging as hyperintense areas on T1-weighted sequences. We also observed similar abnormalities in the basal ganglia of patients with chronic renal failure undergoing maintenance hemodialysis. Our aim was to evaluate the pallidal signal intensity on T1-weighted images in a series of patients undergoing hemodialysis, with further evaluation of serum manganese levels and neurologic correlation, comparing them with patients with chronic renal failure without dialytic treatment. MATERIALS AND METHODS: We performed MR imaging examinations in 9 patients with chronic renal failure, 5 of whom were undergoing hemodialysis. An experienced neuroradiologist scrutinized the presence of symmetric hyperintensities in the basal ganglia on T1-weighted sequences. We also determined the serum manganese levels and performed the neurologic evaluations in all patients. RESULTS: All patients undergoing hemodialysis presented elevated serum manganese levels and symmetric hyperintensities within the globus pallidus. In this group, 4 patients presented with parkinsonian symptoms, myoclonus, and syndromes with vestibular and vestibular-auditory symptoms. The patients without dialytic treatment presented with neither bilaterally increased T1 MR imaging signal intensity within the globus pallidus nor symptoms of manganism. CONCLUSION: Our preliminary results demonstrated the occurrence of bilateral pallidal hyperintensity on T1-weighted images in all patients undergoing hemodialysis associated with high serum manganese levels, revealing a new association.

Motor neuron disease associated with non-fluent rapidly progressive aphasia: case report and review of the literature.

The superimposed clinical features of motor neuron disease (MND) and frontotemporal lobar degeneration (FTLD) comprise a rare neurological overlap syndrome that represents a diagnostic challenge to neurologists. Currently, FTLD-MND is considered a distinct entity and its clinicopathological basis has recently been reviewed. Our aim is to present a patient with MND and non-fluent rapidly progressive aphasia with clinical, imaging and histopathological correlation, as well as a brief review of the literature. We demonstrated the selective corticospinal tract (CST) and temporal lobe involvement using T1 spin-echo with an additional magnetization transfer contrast pulse on resonance (T1 SE/MTC) and FLAIR MR sequences in our patient, with further clinical and histopathological correlation. To the best of our knowledge, there is no description about the use of these particular MR sequences in the evaluation of FTLD-MND patients.

Trigeminal involvement in multiple sclerosis: magnetic resonance imaging findings with clinical correlation in a series of patients.

Trigeminal involvement detected by magnetic resonance imaging (MRI) in multiple sclerosis (MS) patients is usually associated with trigeminal neuralgia (TN) or painless paraesthesia in the trigeminal distribution. Our aim is to review the incidence of trigeminal involvement on MRI in a series of patients with MS at our institution, with further clinical correlation. We reviewed MRI scans of 275 MS patients for the presence of gadolinium enhancement on postcontrast T1-weighted images, anatomical and signal abnormalities on different sequences at the pontine trigeminal root entry zone (REZ) and in the cisternal portion of the nerves. We observed enhancement in the cisternal portion of the nerves and signal abnormalities (with or without enhancement) at the pontine trigeminal REZ in 8 (2.9%) patients, and enhancement was bilateral in 6 (75%) of those. Despite the inflammatory activity, none of them had TN and 3 (37.5%) had only painless paraesthesias in the correspondent V3 distribution. We also found a marked trigeminal hypertrophy in 2 (25%) patients, both with a longer period of disease. Our results confirm a high and clinically silent incidence of trigeminal involvement in MS patients, and suggest a simultaneous role of the central and peripheral type of myelin in trigeminal demyelination.

Magnetic resonance findings in amyotrophic lateral sclerosis using a spin echo magnetization transfer sequence. Preliminary report.

We present the magnetic resonance (MR) findings of five patients with amyotrophic lateral sclerosis (ALS) using a spin-echo sequence with an additional magnetization transfer (MT) pulse on T1-weighted images (T1 SE/MT). These findings were absent in the control group and consisted of hyperintensity of the corticospinal tract. Moreover we discuss the principles and the use of this fast but simple MR technique in the diagnosis of ALS.