Incidental finding of juvenile angiofibroma from pre-orthodontic radiographs: two case reports and a literature review.

This case series presents two asymptomatic cases of juvenile angiofibroma which were initially incidentally identified in pre-orthodontic radiographs. Juvenile angiofibroma is an uncommon, locally aggressive benign, vascular neoplasm with invasive growth patterns. Due to the hypervascularity of these tumours, there are biopsy associated risks and multi-slice computed tomography, magnetic resonance imaging and angiography are usually employed for diagnosis. Early pre-symptomatic identification of this lesion facilitates early management and limiting potential life-threatening complications. This highlights the importance of thorough interpretation of dental radiographs, including the evaluation of structures which are not in the primary region of interest. © 2022 Australian Dental Association.

Mirror neuron system activation in children with developmental coordination disorder: A replication functional MRI study.

BACKGROUND: It has been hypothesised that abnormal functioning of the mirror neuron system (MNS) may lead to deficits in imitation and the internal representation of movement, potentially contributing to the motor impairments associated with developmental coordination disorder (DCD). AIMS: Using fMRI, this study examined brain activation patterns in children with and without DCD on a finger adduction/abduction task during four MNS activation states: observation; motor imagery; execution; and imitation. METHODS AND PROCEDURES: Nineteen boys (8.25-12.75 years) participated, including 10 children with DCD (≤16th percentile on MABC-2; no ADHD/ASD), and nine typically developing controls (≥25th percentile on MABC-2). OUTCOMES AND RESULTS: Even though children with DCD displayed deficits behaviourally on imitation (Sensory Integration & Praxis Test Subtests) and motor imagery assessments prior to scanning, no differences in MNS activation were seen between the DCD and control groups at a neurological level, with both groups activating mirror regions effectively across conditions. Small clusters of decreased activation during imitation were identified in non-mirror regions in the DCD group, including the thalamus, caudate, and posterior cingulate - regions involved in motor planning and attentional processes. CONCLUSIONS AND IMPLICATIONS: The results of this study do not provide support for the MNS dysfunction theory as a possible causal mechanism for DCD. Further research to explore attentional and motor planning processes and how they may interact at a network level may enhance our understanding of this complex disorder.

Fulminant Anti-GAD antibody encephalitis presenting with status epilepticus requiring aggressive immunosuppression.

Antibodies against glutamic acid decarboxylase (GAD) are reported in association with numerous neurological conditions including temporal lobe epilepsy and limbic encephalitis. We report a case of Anti-GAD-Antibody associated encephalitis presenting with epilepsia partialis continua (EPC) progressing to a fulminant encephalopathy preferentially affecting the frontal lobes associated with coma and refractory status epilepticus. The abnormalities identified on MRI included marked bilateral frontal lobe involvement which has not been reported in other auto-immune encephalitides and may be specific for Anti-GAD-Antibody associated encephalitis. Similar to the majority of cases of Anti-GAD associated neurological disturbance no underlying malignancy was identified. Treatment with high dose corticosteriods, IVIG and plasmapheresis had minimal response, but escalation of treatment with rituximab and cyclophosphamide was associated with clinical improvement, reducing antibody titers and resolution of MRI changes.

A neuropsychological profile of off-diet adults with phenylketonuria.

The metabolic disorder phenylketonuria (PKU) is treated early by a low-phenylalanine diet. While this prevents global cognitive impairment, some patients still experience cognitive and neurophysiological abnormalities. Neuropsychological testing of early treated, currently off-diet, PKU patients attending an adult PKU clinic showed a reduction in the Perceptual Organization Index (POI), Processing Speed Index (PSI) from the Wechsler Adult Intelligence Scale Third Edition (WAIS-III), and Part A of the Trail Making Test for the PKU group relative to controls. Taken together, these results supported a profile of reduced information-processing speed.

Meta-analysis of neuropsychological symptoms of adolescents and adults with PKU.

Phenylketonuria (PKU; OMIM 261600) is an autosomal recessive inborn error of phenylanaline metabolism. PKU is characterized by deficient or defective phenylalanine hydroxylase activity and persistantly increased levels of the essential amino acid phenylalanine in the circulation. The present article examines current understanding of the etiology of PKU, along with a meta-analysis examining neuropsychological and intellectual presentations in continuously treated adolescents and adults. Patients with PKU differed significantly from controls on Full-Scale IQ, processing speed, attention, inhibition, and motor control. Future research utilizing an integrative approach and detailed analysis of specific cognitive domains will assist both the scientist and clinician, and ultimately the patient.

Two cases of methanol poisoning: CT and MRI features.

Methanol poisoning in Australia is now very rare as methanol has been removed from methylated spirits. In acute intoxication methanol may result in a wide range of damage to the central nervous system. Few cases have been imaged with MRI. We present two cases and their striking neuroimaging findings with a discussion of the published work on methanol poisoning.

Event-related potentials elicited during a visual Go-Nogo task in adults with phenylketonuria.

OBJECTIVE: The aim of the present study was to examine the nature of previously reported deficits in sustained attention and response inhibition in adults with the developmental disorder, phenylketonuria (PKU). METHODS: This study used event-related potentials (ERPs) to examine the performance of PKU adults (n=9) and a matched control group (n=9) on a visual Go-Nogo task. RESULTS: Comparison of behavioural measures between the PKU and control groups failed to reach statistical significance, yet analysis of the ERPs showed statistically significant amplitude reductions in the P1 and N1 components elicited following presentation of stimuli, and a reduction in the amplitude of the N2 component elicited following presentation of Nogo stimuli. CONCLUSIONS: These results suggest that adults with PKU, despite being continuously treated from birth, manifest subtle impairments in distinct aspects of information processing including early sensory processing of visually presented information, as well as impairments in inhibitory functions. SIGNIFICANCE: The results contribute to an understanding of the neurophysiological mechanisms that are implicated in PKU and highlight the sensitivity of ERP techniques for the identification of the loci of information processing deficits in clinical groups.

Paradoxical embolization via a patent foramen ovale following acute pulmonary embolism.

The foramen ovale is usually obliterated following establishment of the adult circulation but remains patent in 25% of individuals. This potential communication between the venous and arterial circulations can allow thromboembolic material to bypass the lungs and enter the systemic circulation. We report two cases of paradoxical embolization through a patent foramen ovale following acute large pulmonary embolism (PE) and discuss the factors that predispose to paradoxical embolization following PE.

Endovascular treatment of intracranial aneurysms with Guglielmi detachable coils: analysis of midterm angiographic and clinical outcomes.

BACKGROUND AND PURPOSE: The previous decade has witnessed increasing application of Guglielmi detachable coils (GDCs) for the treatment of intracranial aneurysms. However, the midterm angiographic and clinical outcomes are not well documented. We report here the angiographic and clinical outcomes of patients treated with GDCs over an 8-year period. METHODS: Between 1992 and 1998, 144 patients with 160 intracranial aneurysms were treated with GDCs. Clinical follow-up data were obtained from medical records, questionnaires, and telephone interviews. Angiographic studies were reviewed by 2 neuroradiologists to obtain consensus regarding the degree of aneurysm occlusion. RESULTS: Eighty-one patients had ruptured aneurysms; 63 had unruptured aneurysms. Technical success was achieved in 91% of patients, with complete aneurysm occlusion in 46%, neck remnants in 16%, and residual body filling in 38%. Angiographic follow-up revealed that residual body filling in some aneurysms was resolved, small neck remnants were stable, and the recanalization rate decreased with time. All 63 patients with unruptured aneurysms were discharged from hospital with independent clinical status (Glasgow Outcome Score, 1 or 2). For patients with ruptured aneurysms, discharge clinical status correlated with the Hunt & Hess clinical grade at the time of treatment. Clinical follow-up for a minimum of 2 years was available in 98.5% of patients. Ninety-four percent of patients treated for unruptured aneurysms were independent at 2 years, and 82% of Hunt & Hess grade I to II patients were independent. CONCLUSIONS: Coil embolization is a safe and effective treatment for both ruptured and unruptured aneurysms. Increasing angiographic stability is demonstrated in treated aneurysms up to 3 years from coil embolization. Therefore, follow-up angiography until this time is advisable.

FLAIR imaging in the follow-up of low-grade gliomas: time to dispense with the dual-echo?

Fluid-attenuated inversion-recovery (FLAIR) imaging has established its utility in neuroimaging. We propose this imaging sequence as a replacement for proton density (PD) and T2-weighted spin-echo sequences in the follow-up of low-grade glioma. 26 MRI examinations of 18 patients with such tumours were reviewed by three neuroradiologists and a neurosurgeon. FLAIR was found to be superior for appreciation of the lesion (91% of studies) and for demonstration of its margin (92%). FLAIR was also better at showing different tumour components, particularly in regions difficult to demonstrate in some planes, such as the vertex in axial imaging. The sequence also defines the postoperative cavity, shows the least amount of susceptibility effect associated with surgical clips, and demonstrates local spread (to white matter tracts, subependymal and capsular) more distinctly. We conclude that FLAIR can replace PD and T2-weighted spin-echo imaging in radiological follow-up of low-grade glioma.

Perfusion magnetic resonance abnormalities in patients with sickle cell disease.

Neurological complications are common in sickle cell disease (SCD). However, it is often difficult to relate the clinical presentation to conventional neuroimaging, because subclinical infarction is common and stroke has been described in the absence of large-vessel disease. We studied 48 patients with SCD aged 4-34 (median 13) years with T2-weighted, diffusion and perfusion magnetic resonance imaging (MRI) and with MR angiography. Forty-four underwent transcranial Doppler (TCD). Abnormalities on perfusion imaging were seen in 25 cases, 24 of whom had been symptomatic. The remaining patient had evidence of executive dysfunction and reduced perfusion in the frontal lobes. The perfusion abnormality was larger than the area of infarction in 9 patients and was seen in an arterial distribution with no infarction in a further 9. In 3 patients with transient ischemic attacks, perfusion abnormalities were demonstrated in the absence of any other neuroimaging abnormalities, and perfusion changes were seen in 3 others despite normal MR angiography and TCD. Perfusion abnormalities are associated with neurological symptoms in patients with SCD, whether or not MRI, MR angiography, and TCD are abnormal. It is likely that this technique will guide management in individual patients.

Dorsal dens angulation and a Chiari type malformation in a Cavalier King Charles Spaniel.

A nineteen month old Cavalier King Charles had clinical signs consistent with a cervical myelopathy. Radiologically there was abnormal angulation of the dens with cervical spinal cord compression and a Chiari type malformation of the atlanto-occipital region. The condition and method of investigation is discussed.

Diffusion and perfusion magnetic resonance imaging in childhood stroke.

Two magnetic resonance imaging techniques, diffusion and perfusion imaging, are being used increasingly for evaluation of pathophysiology of stroke. This article introduces these techniques and reports some initial studies using these approaches, together with conventional T2-weighted magnetic resonance imaging, for investigation of childhood stroke. It is shown that the combination of T2-weighted and diffusion images can provide information about the timing of stroke events in childhood, and perfusion imaging can detect abnormalities not visible by other magnetic resonance imaging techniques. These magnetic resonance methods therefore should play an important role in investigation of children with stroke and could be of particular value in studies of at-risk populations of children such as those with sickle cell disease.

Contrast-enhanced MR angiography in patients with carotid artery stenosis: comparison of two different techniques with an unenhanced 2D time-of-flight sequence.

Conventional time-of-flight (TOF) MR angiography (MRA) in carotid artery stenosis relies on flow-related enhancement to produce signal from vascular structures. Intravoxel phase dispersion, due to vortices, causes loss of signal and is the reason for the tendency to overestimate the degree of stenosis. In contrast-enhanced MRA, intravascular signal is mainly dependent on T1 shortening of the blood. We compared first-pass contrast-enhanced MRA (contrast-enhanced 3D gradient echo, ce3D GRE) and contrast-enhanced 2D TOF (ce2D TOF) sequences with an unenhanced 2D TOF in 13 patients with carotid artery stenosis, assessing delineation of the carotid bifurcation, enhancement of veins and grade of stenosis. The contrast-enhanced techniques produced more morphological detail, the ce3D GRE being superior to the ce2D TOF. Four carotid arteries were reclassified into lesser stenosis categories using the ce3D GRE technique. However, seven carotid arteries (27%) were rated as nondiagnostic on the ce3D GRE, mainly due to masking of the carotid bifurcation by veins. The latter can be avoided by decreasing the acquisition time; on our 1.5-T system we could achieve a minimum time of 23 s per 3D GRE. Further reduction of acquisition time would be necessary to incorporate this method into clinical routine, requiring higher-performance gradients, which are not available in many UK hospitals.

Long-term outcome of brain manganese deposition in patients on home parenteral nutrition.

Manganese intoxication has been described in children on long term parenteral nutrition presenting with liver and nervous system disorders. Cases are reported of a brother and sister on long term parenteral nutrition with hypermanganesaemia and basal ganglia manganese deposition, detected by magnetic resonance imaging (MRI), without overt neurological signs. Following reduction of manganese intake, basal ganglia manganese was monitored by repeated MRI, and neurological and developmental examinations. An MRI intensity index of the globus pallidus declined over a three year period from 0.318 and 0.385 to 0.205 and 0.134 with concomitant falls in whole blood manganese from 323 and 516 to 226 and 209 nmol/l (normal range, 73-210 nmol/l). Unlike adult experience these children developed normally without neurological signs. In conclusion, deposited manganese is removed from neural tissue over time and the prognosis is good when neurological manifestations and liver disease are absent.