Phenotypic bases of NOTCH2NLC GGC expansion positive neuronal intranuclear inclusion disease in a Southeast Asian cohort.

Neuronal intranuclear inclusion disease (NIID) is a neurodegenerative disorder associated with GGC repeats of >60 to 500 copies in the 5'-untranslated region of NOTCH2NLC. The clinical and genetic characterization of NIID outside of East Asia remains unknown. We identified twelve patients who underwent genetic testing using long-read sequencing or repeat primed polymerase chain reaction. All were positive for a GGC repeat expansion; the median repeat length was 107 (range 92-138). Ten were Chinese and two of Malay ethnicity. Age at onset ranged from 50 to 69 years. Eight (66.7%) patients had dementia, while four (33.3%) patients were oligosymptomatic, without typical NIID symptoms of dementia, Parkinsonism, or muscle weakness. GGA interruptions within the GGC expansion were present in four patients; the number of GGA interruptions was highest (6.71%) in the patient with the earliest age at onset (50 years). Median plasma neurofilament light level was 47.3 pg/mL in seven patients (range 26-380 pg/mL). The highest level (380 pg/mL) was found in one patient who experienced an encephalitic episode. Overall, we describe a cohort of genetically confirmed NIID patients from Southeast Asia and provide further information that the presence of GGA interruptions within GGC repeat expansions may serve as a potential genetic modifier in NIID.

NOTCH2NLC GGC Repeat Expansions Are Associated with Sporadic Essential Tremor: Variable Disease Expressivity on Long-Term Follow-up.

We screened 662 subjects comprising 462 essential tremor (ET) subjects (285 sporadic, 125 with family history, and 52 probands from well-characterized ET pedigrees) and 200 controls and identified pathogenic NOTCH2NLC GGC repeat expansions in 4 sporadic ET patients. Two patients were followed up for >1 decade; one with 90 repeats remained an ET phenotype that did not evolve after 40 years, whereas another patient with 107 repeats developed motor symptoms and cognitive impairment after 8 to 10 years. Neuroimaging in this patient revealed severe leukoencephalopathy; diffusion-weighted imaging hyperintensity in the corticomedullary junction and skin biopsy revealed intranuclear inclusions suggestive of intranuclear inclusion body disease (NIID). No GGC repeats of >60 units were detected in familial ET cases and controls, although 4 ET patients carried 47 to 53 "intermediate" repeats. NOTCH2NLC GGC repeat expansions can be associated with sporadic ET. Carriers presenting with a pure ET phenotype may or may not convert to NIID up to 4 decades after initial tremor onset. ANN NEUROL 2020;88:614-618.

Nipah Virus Infection.

Nipah virus, a paramyxovirus related to Hendra virus, first emerged in Malaysia in 1998. Clinical presentation ranges from asymptomatic infection to fatal encephalitis. Malaysia has had no more cases since 1999, but outbreaks continue to occur in Bangladesh and India. In the Malaysia-Singapore outbreak, transmission occurred primarily through contact with pigs, whereas in Bangladesh and India, it is associated with ingestion of contaminated date palm sap and human-to-human transmission. Bats are the main reservoir for this virus, which can cause disease in humans and animals. There are currently no effective therapeutics, and supportive care and prevention are the mainstays of management.

Progressive Supranuclear Gaze Palsy with Predominant Cerebellar Ataxia: A Case Series with Videos.

Progressive supranuclear palsy (PSP) with predominant cerebellar ataxia (PSP-C) is a rare phenotype of PSP. The clinical and radiological features of this disorder remain poorly characterized. Through a retrospective case series, we aim to characterize the clinical and radiological features of PSP-C. Four patients with PSP-C were identified: patients who presented with prominent cerebellar dysfunction that disappeared with the progression of the disease. Supranuclear gaze palsy occurred at a mean of 2.0 ± 2.3 years after the onset of ataxia. Mild cerebellar volume loss and midbrain atrophy were detected on brain imaging, which are supportive of a diagnosis of PSP. Videos are presented illustrating the co-existence of cerebellar signs and supranuclear gaze palsy and the disappearance of cerebellar signs with disease progression. Better recognition and the development of validated diagnostic criteria would aid in the antemortem recognition of this rare condition.

MRI in spinal cord decompression sickness.

INTRODUCTION: Spinal cord decompression sickness (DCS) is a rare condition that can lead to spinal cord infarction. Despite the low incidence of diving-related DCS, we have managed to collect the data and MRI findings of seven patients who have been diagnosed with and treated for DCS in our local hyperbaric facility. This study describes the clinical presentation, MRI spinal cord findings, treatment administered and outcome of these patients. METHODS: The patient medical records, from 1997 to 2007, were retrospectively reviewed. All patients with a final diagnosis of DCS and who underwent examination were included. The images were independently reviewed by two radiologists who recorded the location and number of lesions within the spinal cord. The Frankel grading was used to assess the initial and clinical outcome response. RESULTS: Patchy-increased T2W changes affecting several levels at the same time were found. Contrary to the popular notion that venous infarction is the leading cause of DCS, most of our patients also demonstrated affliction of grey matter, which is typically seen in an arterial pattern of infarction. Initial involvement of multiple (>6) spinal cord levels was associated with a poor outcome. Patients who continued to have multiple neurological sequelae with less than 50% resolution of symptoms despite recompression treatment were also those who had onset of symptoms within 30 min of resurfacing. CONCLUSIONS: DCS is probably a combination of both arterial and venous infarction. Short latency to the onset of neurological symptoms and multilevel cord involvement may be associated with a poorer outcome.

The iPad tablet computer for mobile on-call radiology diagnosis? Auditing discrepancy in CT and MRI reporting.

Tablet computers such as the iPad, which have a large format, improved graphic display resolution and a touch screen interface, may have an advantage compared to existing mobile devices such as smartphones and laptops for viewing radiological images. We assessed their potential for emergency radiology teleconsultation by reviewing multi-image CT and MRI studies on iPad tablet computers compared to Picture Archival and Communication Systems (PACS) workstations. Annonymised DICOM images of 79 CT and nine MRI studies comprising a range of common on-call conditions, reported on full-featured diagnostic PACS workstation by one Reporting Radiologist, were transferred from PACS to three iPad tablet computers running OsiriX HD v 2.02 DICOM software and viewed independently by three reviewing radiologists. Structured documentation was made of major findings (primary diagnosis or other clinically important findings), minor findings (incidental findings), and user feedback. Two hundred and sixty four readings (88 studies read by three reviewing radiologists) were compared, with 3.4 % (nine of 264) major discrepancies and 5.6 % (15 of 264) minor discrepancies. All reviewing radiologists reported favorable user experience but noted issues with software stability and limitations of image manipulation tools. Our results suggest that emergency conditions commonly encountered on CT and MRI can be diagnosed using tablet computers with good agreement with dedicated PACS workstations. Shortcomings in software and application design should be addressed if the potential of tablet computers for mobile teleradiology is to be fully realized.

Arterial Spin Labeling: a one-stop-shop for measurement of brain perfusion in the clinical settings.

Arterial Spin Labeling (ASL) has opened a unique window into the human brain function and perfusion physiology. Altogether fast and of intrinsic high spatial resolution, ASL is a technique very appealing not only for the diagnosis of vascular diseases, but also in basic neuroscience for the follow-up of small perfusion changes occurring during brain activation. However, due to limited signal-to-noise ratio and complex flow kinetics, ASL is one of the more challenging disciplines within magnetic resonance imaging. In this paper, the theoretical background and main implementations of ASL are revisited. In particular, the different uses of ASL, the pitfalls and possibilities are described and illustrated using clinical cases.

Early deep vein thrombosis: incidence in Asian stroke patients.

INTRODUCTION: Deep venous thrombosis (DVT) is thought to be less common in Asians than in the Caucasian population. The incidence of asymptomatic DVT in high-risk groups in the Asian population has not been well studied. While DVT incidence among Caucasian stroke patients has been extensively studied and the need for prophylaxis established, the lack of data in Asian patients leaves physicians with no firm basis for adopting prophylactic protocols in the local population. Our aim was to prospectively establish the incidence of early DVT in immobilised stroke patients in a heterogenous Asian population. MATERIALS AND METHODS: We screened 44 patients with significant hemiplegia from acute stroke. Doppler ultrasound, the currently accepted method of investigation for DVT, was used to study patients on admission and at 1 week post-stroke. While there was no standard prophylactic regime in use, none of the patients received heparin and only 2 were given compression stockings. RESULTS: The incidence of DVT at 1 week was 2.4%. Review at 1 month detected another patient with DVT, bringing the overall incidence at 1 month to 4.8%. This is lower than in Caucasian populations, but is similar to another local study on a different group of high-risk patients. CONCLUSION: The low incidence of early DVT in hospitalised stroke patients of Asian ethnicity does not justify routine screening for this population. Further research to validate this should ideally include a comparison test for DVT as ultrasound may have inherently lower sensitivity in an asymptomatic population.

Disseminated spread of recurrent oligodendroglioma (WHO grade II).

Oligodendroglioma is a relatively uncommon primary brain tumour. The occurrence of metastatic dissemination of oligodendroglioma is rare and usually occurs in patients with anaplastic oligodendroglioma. The dissemination of WHO Grade II oligodendroglioma can occur and we report a patient with an initial diagnosis of a left temporal oligodendroglioma who presented with disseminated disease in the left temporal lobe, sellar region, medulla oblongata, both frontal lobes and ventricles more than 8 years later. Histology at dissemination showed anaplastic oligodendroglioma. Similar reports of metastatic dissemination of oligodendrogliomas reveal that the tumours may remain as WHO Grade II or may progress to anaplastic oligodendroglioma at metastasis. However, regardless of the histological grade at metastasis, the prognosis of metastatic oligodendroglioma is poor.

Multi-voxel MR spectroscopic imaging of the brain: utility in clinical setting-initial results.

BACKGROUND AND PURPOSE: Compared to single voxel methods, MR spectroscopic imaging (MRSI) of the brain provides metabolic information with improved anatomical coverage and spectral resolution, but may be difficult to perform in the clinical setting. We evaluate the factors influencing spectral quality in MRSI using a semi-automated method, focussing on lipid contamination, and phase correction errors related to magnetic field inhomogeneity. METHODS: We retrospectively analysed MRSI studies planned by radiologists and radiographers. Two-dimensional MRSI studies using point-resolved spectroscopy (PRESS) localisation, at long echo time (135 or 144 ms) were acquired on a 1.5 T scanner. Studies that contained lipid contamination and abnormally inverted spectra were reviewed and the latter correlated with anatomic location at the base of skull, and with the area of the region of interest (ROI) studied. RESULTS: Of 128 consecutive MRSI studies, six showed abnormal inverted spectra, of which four were acquired at the base of skull. Multivariate logistic regression analysis showed that study location at the base of skull, but not larger ROI, was a significant predictor for the risk of being affected by inverted spectra (RR for base of skull: 11.76, 95% CI: 1.86-74.18, P=0.009. RR for area of ROI: 3.68, 95% CI: 0.57-23.67, P=0.170). Seven studies showed lipid contamination; all were in close proximity to the overlying scalp. CONCLUSION: Using a semi-automated acquisition and post-processing method, MRSI can be successfully applied in the clinical setting. However, care should be taken to avoid regions of high magnetic field inhomogeneity at the base of skull, and lipid contamination in voxels prescribed near the scalp.

Perfusion imaging using arterial spin labeling.

Arterial spin labeling is a magnetic resonance method for the measurement of cerebral blood flow. In its simplest form, the perfusion contrast in the images gathered by this technique comes from the subtraction of two successively acquired images: one with, and one without, proximal labeling of arterial water spins after a small delay time. Over the last decade, the method has moved from the experimental laboratory to the clinical environment. Furthermore, numerous improvements, ranging from new pulse sequence implementations to extensive theoretical studies, have broadened its reach and extended its potential applications. In this review, the multiple facets of this powerful yet difficult technique are discussed. Different implementations are compared, the theoretical background is summarized, and potential applications of various implementations in research as well as in the daily clinical routine are proposed. Finally, a summary of the new developments and emerging techniques in this field is provided.

Providing optimal radiology service in the severe acute respiratory syndrome outbreak: use of mobile CT.

OBJECTIVE: Severe acute respiratory syndrome (SARS) is a serious atypical pneumonia caused by a novel pathogen. We describe our experience using a mobile CT scanner in an improvised isolation ward with life-support systems, portable lead shielding, and strict barrier nursing. This scanner was used exclusively for patients with SARS and patients with other illnesses who were also thought to have SARS. This arrangement freed the other CT scanners in the main department for non-SARS patients. In 5 weeks, 90 studies were performed; no cases of cross infection of health care workers were reported. CONCLUSION: Mobile CT may be used to provide dedicated radiology services to seriously ill patients requiring strict isolation during an infectious disease outbreak.

Serial diffusion-weighted magnetic resonance imaging in adult-onset citrullinaemia.

A 25-year-old Chinese man presented with a 2-year history of recurrent coma. His plasma ammonia level was extremely elevated, with raised citrulline level and absence of argininosuccinic acid. Adult-onset citrullinaemia, a condition rarely reported outside the Japanese population, was diagnosed. Serial magnetic resonance (MR) imaging, including diffusion-weighted (DW) studies, showed initial involvement of the insula cortex and cingulate gyrus, changing to a pattern of multiple small lesions in the depths of the cortical sulci. This changing pattern of lesions over time on DW MR imaging has not previously been described in adult-onset citrullinaemia.