FDG PET and PET CT is a sensitive and specific diagnostic tool for NF1-associated MPNST. Other PET tracers will be required to solve the problem of predicting tumour grade.

Vici syndrome is a rare, genetically unresolved congenital multisystem disorder comprising agenesis of the corpus callosum, cataracts, immunodeficiency, cardiomyopathy, and hypopigmentation. An associated neuromuscular phenotype has not previously been described in detail. We report on an infant with clinical features suggestive of Vici syndrome and additional sensorineural hearing loss. Muscle biopsy revealed several changes including markedly increased variability in fiber size, increased internal nuclei, and abnormalities on Gomori trichrome and oxidative stains, raising a wide differential diagnosis including neurogenic atrophy, centronuclear myopathy (CNM) or a metabolic (mitochondrial) cytopathy. Respiratory chain enzyme studies, however, were normal and sequencing of common CNM-associated genes did not reveal any mutations. This case expands the clinical spectrum of Vici syndrome and indicates that muscle biopsy ought to be considered in infants presenting with suggestive clinical features. In addition, we suggest that Vici syndrome is considered in the differential diagnosis of infants presenting with congenital callosal agenesis and that additional investigation has to address the possibility of associated ocular, auditory, cardiac, and immunologic involvement when this radiologic finding is present.

AIM Mutations in the SLC16A2 gene have been implicated in Allan–Herndon–Dudley syndrome (AHDS), an X-linked learning disability* syndrome associated with thyroid function test (TFT) abnormalities. Delayed myelination is a non-specific finding in individuals with learning disability whose genetic basis is often uncertain. The aim of this study was to describe neuroimaging findings and neurological features in males with SLC16A2 gene mutations. METHOD We reviewed brain magnetic resonance imaging (MRI) findings and neurological features in a cohort of five males aged between 1 year 6 months and 6 years (median 4y) from four families harbouring SLC16A2 gene mutations. RESULTS The participants presented aged between 4 and 9 months with initial hypotonia and subsequent spastic paraparesis with dystonic posturing and superimposed paroxysmal dyskinesias. Dystonic cerebral palsy was the most common initial clinical diagnosis, and AHDS was suspected only retrospectively, considering the characteristically abnormal thyroid function tests, with high serum tri-iodothyronine (T3), as the most consistent finding. Brain MRI showed absent or markedly delayed myelination in all five participants, prompting the suspicion of Pelizaeus–Merzbacher disease in one patient. INTERPRETATION Our findings indicate a consistent association between defective neuronal T3 uptake and delayed myelination. SLC16A2 involvement should be considered in males with learning disability, an associated motor or movement disorder, and evidence of delayed myelination on brain MRI. Although dysmorphic features suggestive of AHDS are not always present, T3 measurement is a reliable screening test.

There are very limited published data on the neurologic complications associated with coronavirus disease 2019 in the pediatric population. Here we present the first 2 pediatric cases of presumed COVID-19 related cytotoxic lesions of the corpus callosum. Similar to reports in adults, these cases suggest that the COVID-19 infection in children may rarely mediate a hyperinflammatory response that can cause CNS pathology. As the pandemic continues further, the presentation of cytotoxic lesions of the corpus callosum should prompt radiologists to consider COVID-19, among other known causes. ABBREVIATIONS: CLOCC¼ cytotoxic lesions of the corpus callosum; COVID-19 ¼ coronavirus disease 2019; CRP ¼ C-reactive protein; RT-PCR ¼ real-time reverse transcriptase polymerase chain reaction; SARS-CoV-2 ¼ Severe Acute Respiratory Syndrome coronavirus 2A s of June 2, 2020, over 6.1 million cases of coronavirus disease 2019 (COVID-19) have been recorded and over 370,000 people have died. 1 Most confirmed cases have been in the adult population with only a small percentage (1%-2%) of reported cases being in children. 2 In the pediatric population, COVID-19 infection seems to be often asymptomatic or associated with mild respiratory symptoms. 2 As yet, there have been very limited reports of neurologic complications in children. Here we report the first series of pediatric neurologic presentations with COVID-19-associated cytotoxic lesions of the corpus callosum (CLOCC). This presentation has been related to other viral infections, but not yet demonstrated in association with COVID-19.

To evaluate the usefulness of neuroimaging in children with idiopathic intracranial hypertension, brain magnetic resonance imaging (MRI) scans of children with idiopathic intracranial hypertension and age-matched controls were reviewed. Compared with controls, patients with idiopathic intracranial hypertension had flattening of the posterior sclera in 61% versus 40% of cases, distension of perioptic subarachnoid space in 65% versus 35%, intraocular protrusion of pre-laminar optic nerve in 17% versus 0%, tortuosity of optic nerve in 30% versus 5%, and an empty sella in 26% versus 5% of cases. The presence of 3 or more of the MRI features is 95% specific in predicting idiopathic intracranial hypertension. The observed general anesthetic effect on these neuroimaging features are also minimized when multiple features are taken into account. Magnetic resonance imaging features can assist in suspecting the diagnosis of idiopathic intracranial hypertension in children, provided caution is applied when interpreting imaging performed under a general anesthesia.

Background and Purpose-Ischemic symptoms in patients with moyamoya syndrome (MMS) are usually due to hemodynamically mediated perfusion failure, and identification of abnormal tissue perfusion in these patients is therefore clinically important. Although dynamic susceptibility contrast (DSC) MRI can be used to study tissue perfusion, there are potential technical problems in MMS. This study investigates the scope and limitations of perfusion MRI in the clinical evaluation of such patients. Methods-Thirteen patients with bilateral MMS were studied with the use of structural, diffusion, and perfusion MRI. The DSC MRI data were analyzed both visually and by a quantitative regional analysis, and the relationship between perfusion status and clinical symptoms was investigated. Results-Extensive bilateral DSC MRI abnormalities were observed in all the patients. There was a very heterogeneous distribution of bolus arrival time. The areas of abnormality included the major arterial border zones in all cases, although these usually appeared normal on structural and diffusion MRI. Only the most clinically unstable patients had peak width (defined as time to peak minus bolus arrival time) Ͼ5 seconds on the quantitative regional analysis. Several technical limitations of perfusion quantification in MMS are described, as well as the implications of these limitations in patients with other forms of occlusive large-vessel disease. Conclusions-The

BackgroundCerebral microhaemorrhages are increasingly being recognised as a complication of COVID-19. This observational retrospective study aims to further investigate the potential pathophysiology through assessing the pattern of microhaemorrhage and clinical characteristics of patients with COVID-19 and microhaemorrhage. By comparing with similar patterns of microhaemorrhage in other non-COVID-19 disease, this study aims to propose possible common pathogenic mechanisms.MethodsA retrospective observational case series was performed identifying all patients with COVID-19 complicated by cerebral microhaemorrhage on MRI. The distribution and number of microhaemorrhages were recorded using the microbleed anatomical scale, and patients’ baseline characteristics and salient test results were also recorded.ResultsCerebral microhaemorrhages were noted to have a predilection for the corpus callosum, the juxtacortical white matter and brainstem. All patients had a preceding period of critical illness with respiratory failure and severe hypoxia necessitating intubation and mechanical ventilation.DiscussionThis study demonstrates a pattern of cerebral microhaemorrhage that is similar to the pattern reported in patients with non-COVID-19 related critical illness and other causes of severe hypoxia. This raises questions regarding whether microhaemorrhage occurs from endothelial dysfunction due the direct effect of SARS-CoV-2 infection or from the secondary effects of critical illness and hypoxia.

Systemic lupus erythematosus (SLE) can affect any part of the central nervous system (CNS) from the cerebrum to the cauda eqina, giving rise to diverse neurological mainfestations. Despite clinically apparent symptoms and signs, imaging will commonly be normal while at times the magnitude of changes demonstrated on MRI may be out of proportion to the clinical presentation. We describe the MRI techniques used in CNS imaging and the pattern of presentation in SLE.