A First Case of Acute Cerebellitis Associated with Coronavirus Disease (COVID-19): a Case Report and Literature Review

Novel coronavirus (severe acute respiratory syndrome-coronavirus-2: SARS-CoV-2), which originated from Wuhan, China, has spread to the other countries in a short period of time. We report a 47-year-old male who was admitted to our hospital due to suffering from progressive vertigo and ataxia for 7 days prior to the admission. Neurological examination revealed cerebellar dysfunction, and brain magnetic resonance imaging (MRI) depicted edema of the cerebellar hemisphere associated with leptomeningeal enhancement. Cerebrospinal fluid (CSF) analysis showed mild lymphocytic pleocytosis, elevated protein, and lactate dehydrogenase. SARS-CoV-2 RNA was detected in the oropharyngeal/nasopharyngeal and CSF specimens. As a result, treatment with lopinavir/ritonavir was initiated, and patient symptoms and signs improved significantly during the course of hospitalization. To the best of our knowledge, this is the first case of acute cerebellitis associated with COVID-19 disease which is reported in the literature so far.

Endovascular treatment for the flow-related aneurysm originating from an anterior inferior cerebellar artery supplying the cerebellar arteriovenous malformation

BACKGROUND

When a flow-related aneurysm originates from an anterior inferior cerebellar artery (AICA) supplying the cerebellar arteriovenous malformation (AVM), the management becomes very complicated. Endovascular treatment (EVT) was an option, but no consensus has been achieved.Methods and materials: A retrospective investigation was performed for patients with flow-related aneurysm originating from an AICA supplying the cerebellar AVM.

RESULTS

Ten patients, harboring 13 aneurysms, were identified. Of the 5 a1 aneurysms, 2 underwent stent assisted coiling, 2 underwent parent artery occlusion (PAO), and 1 was intact. Of the 8 a2 aneurysms, 3 underwent coiling with preservation of the AICA, 3 underwent PAO with Onyx, 1 underwent PAO with coils, and 1 was intact. Seven patients underwent partial embolization of the cerebellar AVM, 3 were intact. One patient died 6 hours postoperatively for cerebellar AVM rebleeding. During a follow-up from 6 months to 6 years, 9 patients had favorable recovery.

CONCLUSION

For the flow-related aneurysm originating from an AICA supplying the cerebellar AVM, the EVT depends on the specific circumstances. When the aneurysm is located at the a1 segment, coiling of the aneurysm with preservation of the parent AICA should be performed. PAO is the last resort. When the a2 aneurysm is proximal to the internal auditory artery, coiling of the aneurysm with preservation of the AICA is preferred. When the aneurysm is distal to the internal auditory artery, PAO can be safely performed.

Orthostatic Enlargement of a Supracerebellar Arachnoid Cyst With Cerebellar Descent Visualized by Upright Computed Tomography

BACKGROUND

Posterior fossa arachnoid cysts are often asymptomatic, but can rarely cause postural headache, the mechanism of which remains unknown.

CASE DESCRIPTION

We present a 40-year-old woman with an asymptomatic supracerebellar arachnoid cyst. Upright computed tomography (CT) showed enlargement of the arachnoid cyst and caudal descent of the cerebellum compared with supine CT with narrowing of the craniocervical junction cerebrospinal fluid space.

CONCLUSIONS

This finding aids in understanding the association of posterior fossa arachnoid cysts with orthostatic headache. Clinicians should be aware of possible posture-related changes in intracranial structures.

An Uncommon Case of Neuroenteric Cyst Located at the Lateral Cerebellomedullary Cistern

We present the case of a 42-year-old woman with a 5-week history of headache, progressive dysphagia, dysphonia, and hoarseness. A brain magnetic resonance imaging revealed an extra-axial cyst of the left lateral cerebellomedullary cistern. The subsequent histopathologic examination diagnosed a neuroenteric cyst. This case sheds light on the pivotal role of histologic identification of neuroenteric cyst, which could be crucial for further diagnostic investigations, especially in pediatric patients.

De Novo KAT5 Variants Cause a Syndrome with Recognizable Facial Dysmorphisms, Cerebellar Atrophy, Sleep Disturbance, and Epilepsy

KAT5 encodes an essential lysine acetyltransferase, previously called TIP60, which is involved in regulating gene expression, DNA repair, chromatin remodeling, apoptosis, and cell proliferation; but it remains unclear whether variants in this gene cause a genetic disease. Here, we study three individuals with heterozygous de novo missense variants in KAT5 that affect normally invariant residues, with one at the chromodomain (p.Arg53His) and two at or near the acetyl-CoA binding site (p.Cys369Ser and p.Ser413Ala). All three individuals have cerebral malformations, seizures, global developmental delay or intellectual disability, and severe sleep disturbance. Progressive cerebellar atrophy was also noted. Histone acetylation assays with purified variant KAT5 demonstrated that the variants decrease or abolish the ability of the resulting NuA4/TIP60 multi-subunit complexes to acetylate the histone H4 tail in chromatin. Transcriptomic analysis in affected individual fibroblasts showed deregulation of multiple genes that control development. Moreover, there was also upregulated expression of PER1 (a key gene involved in circadian control) in agreement with sleep anomalies in all of the individuals. In conclusion, dominant missense KAT5 variants cause histone acetylation deficiency with transcriptional dysregulation of multiples genes, thereby leading to a neurodevelopmental syndrome with sleep disturbance, cerebellar atrophy, and facial dysmorphisms, and suggesting a recognizable syndrome.

Wernekink Commissure Syndrome: A Rare Cause of Bilateral Cerebellar Syndrome

PURPOSE

Focal signs are a big deal in neurology and are among the most important clues leading to diagnosis and localization. Wernekink commissure syndrome is due to lesions in the caudal paramedian midbrain involving the entire decussation of the superior cerebellar peduncles, resulting in the clinical hallmark of a bilateral cerebellar syndrome.

CASE REPORT

A 79-year-old man presented with sudden, severe unsteadiness associated with slurring of speech, binocular double vision, and bilateral hand tremor. Examination showed right INO, moderately severe dysarthria, bilateral dysmetria and dysdiadochokinesia, with severe truncal ataxia and bilateral upper and lower limb ataxia. Also, bilateral coarse tremor was noted in both hands which was present at rest, action and on reaching for objects. Brain MRI revealed an acute infarction involving the Wernekinck decussation in the right caudal midbrain and mesencephalo-pontine junction.

CONCLUSION

The differential of Wernekink Commissure Syndrome is complex, and localization and lateralization are extremely difficult owing to prominent bilateral cerebellar symptoms. The finding of an associated unilateral INO in some cases makes it possible to confidently narrow the list of differentials and localize the lesion to the paramedian tegmentum ipsilateral to the non-adducting eye.

Case Report: A Case of Severe Cryptococcal Immune Reconstitution Inflammatory Syndrome Presenting with Brain and Intradural Abscesses in an HIV Patient

Clinical worsening or new manifestation of cryptococcal disease following initiation of anti-retroviral therapy (ART) in an HIV patient is a hallmark of cryptococcal immune reconstitution inflammatory syndrome (C-IRIS). However, it can be difficult to distinguish IRIS from worsening or new infection. Here, we present a case of severe C-IRIS involving multiple cerebellar, spinal, and intradural abscesses and spinal arachnoiditis 7 months after ART initiation in an AIDS patient with uncertain prior ART compliance. He had multiple prior episodes of cryptococcal meningitis with complications necessitating ventriculoperitoneal shunt placement and was on suppressive fluconazole when he developed worsening brain manifestations. He received empiric anti-cryptococcal re-induction without improvement. All cerebrospinal fluid cultures remained sterile, with negative Cryptococcus PCR testing, and his condition continued to worsen prior to corticosteroid initiation. Ultimately, C-IRIS was diagnosed by brain biopsy. This case demonstrates an extreme in severity of C-IRIS and in the timeline of presentation after ART initiation.

Radiology of post-operative paediatric cerebellar mutism syndrome

BACKGROUND

Post-operative paediatric cerebellar mutism syndrome is a well-recognized complication following posterior fossa tumour resection in children. Over the past few decades, imaging has played an important role in understanding this disorder.

AIM

This review article aims to focus on the disorder from a radiological perspective, summarizing the salient radiological evidence related to the anatomical structures, pathophysiology, and risk factors related to this disorder.

CONCLUSION

Radiological studies have been integral to the improved understanding of this condition. Future large multicentre studies and quantitative analysis techniques will be vital in further refinement of our understanding of this complex condition.

Pediatric post-operative cerebellar mutism syndrome, cerebellar cognitive affective syndrome, and posterior fossa syndrome: historical review and proposed resolution to guide future study

BACKGROUND

Cerebellar mutism (CM), pseudobulbar palsy, posterior fossa syndrome (PFS), and cerebellar cognitive affective syndrome (CCAS) are terms that have been used, sometimes interchangeably, to refer to the complex neurological constellation that occurs following surgical removal of cerebellar and fourth ventricular tumors, mostly in children, but also sometimes in adults.

METHODS

This paper reviews the origins of what is now regarded as pediatric post-operative cerebellar mutism, the cerebellar cognitive affective syndrome, and the neurological manifestations of injury to or disruption of brainstem and cerebellar structures. It examines the specific components of each of these phenomena in the context of the evolving understanding of the role of the cerebellum in nervous system function.

RESULTS

Children undergoing surgical management of tumors in the posterior cranial fossa are at risk of experiencing cranial neuropathies, corticospinal damage, cerebellar ataxia and related motor disorders, neuropsychiatric and cognitive changes, and in some patients, mutism. These clinical presentations are differentiated from each other and examined in the context of the relevant anatomical structures and distributed neural circuits. The term posterior fossa syndrome is not sufficiently helpful in distinguishing the different elements of the clinical phenomena from each other, and because of this lack of precision and specificity, there is consensus among investigators in the international Posterior Fossa Society that the designation be retired.

CONCLUSIONS

Using contemporary brain imaging methods and guided by careful clinical observation and meticulous definition of clinical phenomenology, it is now feasible to perform detailed structure function correlation analyses to achieve two critical goals in the care of children with tumors in the posterior cranial fossa. The first goal is to identify and understand the neural circuits responsible for the different manifestations-arousal, cranial neuropathies, long tract signs, cerebellar motor syndrome, cerebellar vestibular syndrome, cerebellar cognitive affective syndrome including emotional dyscontrol, and mutism. The second goal is to transform this knowledge into practical clinical intervention, preventing the complications inherent in the necessary surgery whenever possible, and develop new approaches to treatment with methods including brain modulation targeting interconnected nodes of the damaged neural circuits.

The Cerebellar Cognitive Affective/Schmahmann Syndrome: a Task Force Paper

Sporadically advocated over the last two centuries, a cerebellar role in cognition and affect has been rigorously established in the past few decades. In the clinical domain, such progress is epitomized by the "cerebellar cognitive affective syndrome" ("CCAS") or "Schmahmann syndrome." Introduced in the late 1990s, CCAS reflects a constellation of cerebellar-induced sequelae, comprising deficits in executive function, visuospatial cognition, emotion-affect, and language, over and above speech. The CCAS thus offers excellent grounds to investigate the functional topography of the cerebellum, and, ultimately, illustrate the precise mechanisms by which the cerebellum modulates cognition and affect. The primary objective of this task force paper is thus to stimulate further research in this area. After providing an up-to-date overview of the fundamental findings on cerebellar neurocognition, the paper substantiates the concept of CCAS with recent evidence from different scientific angles, promotes awareness of the CCAS as a clinical entity, and examines our current insight into the therapeutic options available. The paper finally identifies topics of divergence and outstanding questions for further research.

Non-linear spelling in writing after a pure cerebellar lesion

The most common deficits in processing written language result from damage to the graphemic buffer system and refer to semantic and lexical problems or difficulties in phoneme-graphene conversion. However, a writing disorder that has not yet been studied in depth is the non-linear spelling phenomenon. Indeed, although some cases have been described, no report has exhaustively explained the cognitive mechanism and the anatomical substrates underlying this process. In the present study, we analyzed the modality of non-linear writing in a patient affected by a focal cerebellar lesion, who presented with an alteration of the normal trend to write the order of the letters. Based on this evidence, we analyzed the functional connectivity between the cerebellum and the brain network that subtends handwriting and demonstrated how the cerebellar lesion of the patient affected the connections between the cerebellum and cortical areas that support the anatomical system of writing. This is the first report of non-linear spelling in a patient with a lesion outside the fronto-parietal network, specifically with a focal cerebellar lesion. We propose that non-linear writing can be interpreted in view of the role of the cerebellum in timing and sequential processing. Thus, considering the current functional connectivity data, we hypothesize that the cerebellum might be relevant in the mechanism that allows the correct activation timing of letters within a string and placement of the letters in a specific sequential writing order.

Fourth ventricle index: sonographic marker for severe fetal vermian dysgenesis/agenesis

OBJECTIVE

Prenatal diagnosis of midbrain-hindbrain (MB-HB) malformations relies primarily on abnormal size and shape of the cerebellum and retrocerebellar space, particularly 'open fourth ventricle' (4V), the most common indicator of MB-HB malformations. The aim of this study was to present the fourth ventricle index (4VI), and to evaluate its role as a marker for severe vermian dysgenesis/agenesis in cases without open 4V.

METHODS

This was a prospective cross-sectional study of patients with singleton low-risk pregnancy at 14 + 1 to 36 + 6 gestational weeks presenting between May 2016 and November 2017 for routine ultrasound examination. Axial images of the fetal 4V were obtained and the 4VI was calculated as the ratio between the laterolateral and the anteroposterior diameters. Reference ranges were constructed and retrospectively collected values from 44 fetuses with confirmed anomalies involving severe vermian dysgenesis/agenesis (Joubert syndrome and related disorders, rhombencephalosynapsis, cobblestone malformations and cerebellar hypoplasia) but without open 4V were compared with the normal values.

RESULTS

In total, 384 healthy fetuses were enrolled into the study, from which reference ranges were produced, and 44 cases were collected retrospectively. The 4VI in the normal fetuses was always > 1. In affected fetuses, it was always below mean -2 SD and < 1.

CONCLUSIONS

The 4VI is a sonographic marker for severe fetal vermian dysgenesis/agenesis in the absence of an open 4V. It may be incorporated easily into the routine brain scan; 4VI < 1 indicates a need for dedicated fetal neuroimaging for diagnosis and prenatal counseling. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Multiple aneurysms on the subarcuate artery arising from the anterior inferior cerebellar artery in a patient with a Borden type I transverse-sigmoid dural arteriovenous fistula manifesting as subarachnoid hemorrhage: A case report

BACKGROUND

Peripheral anterior inferior cerebellar artery (AICA) aneurysms are rare and commonly associated with vascular malformations, such as cerebellar arteriovenous malformations (AVMs). We present a case wherein multiple AICA feeding aneurysms on the subarcuate artery as a feeding artery of a Borden type I transverse-sigmoid dural arteriovenous fistula (dAVF) manifested as subarachnoid hemorrhage.

CASE DESCRIPTION

A 67-year-old woman presented with acute severe headache. Brain computed tomography (CT) demonstrated subarachnoid hemorrhage mainly in the posterior fossa. A transverse-sigmoid dAVF was detected on magnetic resonance angiography (MRA) and three-dimensional-CT angiography (3D-CTA), with no cortical venous reflex. The patient underwent conventional angiography, which showed multiple aneurysms on a small branch of the AICA, feeding a transverse-sigmoid dAVF (Borden type I). The AICA aneurysms seemed flow dependent and ruptured owing to high-flow arteriovenous shunts through the dAVF. Based on the source images of the MRA, the small artery arising from the AICA was considered the subarcuate artery, and it was confirmed on 3D-CTA after the artery was successfully embolized with Onyx without any complications. Multiple aneurysms on the subarcuate artery are extremely rare, and the artery has not been identified as a feeding artery of the transverse-sigmoid dAVF.

CONCLUSION

A rare case of multiple ruptured aneurysms on the subarcuate artery was reported in a patient with a Borden type I dAVF at the transverse-sigmoid sinuses manifesting as subarachnoid hemorrhage. Onyx embolization of the parent artery occlusion was feasible and useful in treating this type of feeding artery aneurysm of the AICA with a dAVF.

Cerebral small vessel disease in patients with spontaneous cerebellar hemorrhage

BACKGROUND

Spontaneous cerebellar-intracerebral hemorrhage (ICH) can be associated with both cerebral amyloid angiopathy (CAA) and hypertensive small vessel disease (HTN-SVD, i.e. arteriolosclerosis). To better understand the underlying microangiopathy of cerebellar-ICH, we aimed to evaluate the spatial distribution of supratentorial cerebral microbleeds (CMBs) and neuropathologic profiles in these patients.

METHODS

We enrolled consecutive cerebellar-ICH patients. Clinical variables and MRI markers specific for CAA and HTN-SVD were assessed. Patients were classified into categories according to the topography (strictly-lobar, strictly-deep, and mixed) of supratentorial CMBs and comparisons were performed. Available neuropathological material was reviewed to evaluate the presence and severity of arteriolosclerosis and CAA.

RESULTS

Ninety-eight cerebellar-ICH patients were enrolled. Fifty patients (51%) had at least one supratentorial CMB. Twelve patients (12%) had strictly lobar-CMBs, 12 patients (12%) showed strictly deep-CMBs and mixed-CMBs (lobar and deep CMBs) were present in 26 cerebellar-ICH patients (27%). In multivariable analysis, cerebellar-ICH patients with mixed-CMBs were associated with higher prevalence of hypertension (OR 4.9, 95% confidence interval [CI] 1.2-20, p = 0.017) but with lower prevalence of severe centrum-semiovale enlarged perivascular spaces (OR 0.2, CI 0.05-0.8, p = 0.024) when compared to cerebellar-ICH patients with strictly lobar-CMBs. Vascular risk factors and neuroimaging characteristics were similar between strictly deep-CMBs and mixed-CMBs. Six patients had available neuropathological material for analyses and they all showed some degree of arteriolosclerosis.

CONCLUSIONS

Cerebellar-ICH patients frequently show supratentorial CMBs. The mixed-CMBs pattern appears to be the most common. Our radiological and pathological results suggest that the majority of cerebellar-ICH patients harbor HTN-SVD as dominant microangiopathy.

A computational framework for the detection of subcortical brain dysmaturation in neonatal MRI using 3D Convolutional Neural Networks

Deep neural networks are increasingly being used in both supervised learning for classification tasks and unsupervised learning to derive complex patterns from the input data. However, the successful implementation of deep neural networks using neuroimaging datasets requires adequate sample size for training and well-defined signal intensity based structural differentiation. There is a lack of effective automated diagnostic tools for the reliable detection of brain dysmaturation in the neonatal period, related to small sample size and complex undifferentiated brain structures, despite both translational research and clinical importance. Volumetric information alone is insufficient for diagnosis. In this study, we developed a computational framework for the automated classification of brain dysmaturation from neonatal MRI, by combining a specific deep neural network implementation with neonatal structural brain segmentation as a method for both clinical pattern recognition and data-driven inference into the underlying structural morphology. We implemented three-dimensional convolution neural networks (3D-CNNs) to specifically classify dysplastic cerebelli, a subset of surface-based subcortical brain dysmaturation, in term infants born with congenital heart disease. We obtained a 0.985 ± 0. 0241-classification accuracy of subtle cerebellar dysplasia in CHD using 10-fold cross-validation. Furthermore, the hidden layer activations and class activation maps depicted regional vulnerability of the superior surface of the cerebellum, (composed of mostly the posterior lobe and the midline vermis), in regards to differentiating the dysplastic process from normal tissue. The posterior lobe and the midline vermis provide regional differentiation that is relevant to not only to the clinical diagnosis of cerebellar dysplasia, but also genetic mechanisms and neurodevelopmental outcome correlates. These findings not only contribute to the detection and classification of a subset of neonatal brain dysmaturation, but also provide insight to the pathogenesis of cerebellar dysplasia in CHD. In addition, this is one of the first examples of the application of deep learning to a neuroimaging dataset, in which the hidden layer activation revealed diagnostically and biologically relevant features about the clinical pathogenesis. The code developed for this project is open source, published under the BSD License, and designed to be generalizable to applications both within and beyond neonatal brain imaging.

Mitochondrial POLG related disorder presenting prenatally with fetal cerebellar growth arrest

We report the prenatal findings of severe cerebellar growth arrest in two siblings with POLG1 mutations. The first presented with seizures and lactic acidosis immediately after premature birth and was diagnosed with mitochondrial disease on muscle biopsy. Molecular DNA analysis confirmed homozygous missense mutation in the POLG1 gene. The pregnancy of the second sibling was monitored closely by repeat fetal ultrasounds since the parents declined invasive testing. A detailed fetal ultrasound at 19 weeks gestation showed a small cerebellum with transcerebellar diameter (TCD) on axial cranial imaging, measuring below the 5th centile for gestational age. Molecular analysis confirmed the same homozygous familial mutation in the POLG1gene. This report further delineates the phenotypic features of the POLG related disorders and expands it to the prenatal era. Subsequent pregnancies were monitored by molecular analysis, using chorionic villus sampling (CVS).

Cerebellar involvement in autism and ADHD

The cerebellum has long been known for its importance in motor learning and coordination. However, increasing evidence supports a role for the cerebellum in cognition and emotion. Consistent with a role in cognitive functions, the cerebellum has emerged as one of the key brain regions affected in nonmotor disorders, including autism spectrum disorder and attention deficit-hyperactivity disorder. Here, we discuss behavioral, postmortem, genetic, and neuroimaging studies in humans in order to understand the cerebellar contributions to the pathogenesis of both disorders. We also review relevant animal model findings.

Prediction of a multiple sclerosis diagnosis in patients with clinically isolated syndrome using the 2016 MAGNIMS and 2010 McDonald criteria: a retrospective study

BACKGROUND

In 2016, the Magnetic Resonance Imaging in Multiple Sclerosis (MAGNIMS) network proposed modifications to the MRI criteria to define dissemination in space (DIS) and time (DIT) for the diagnosis of multiple sclerosis in patients with clinically isolated syndrome (CIS). Changes to the DIS definition included removal of the distinction between symptomatic and asymptomatic lesions, increasing the number of lesions needed to define periventricular involvement to three, combining cortical and juxtacortical lesions, and inclusion of optic nerve evaluation. For DIT, removal of the distinction between symptomatic and asymptomatic lesions was suggested. We compared the performance of the 2010 McDonald and 2016 MAGNIMS criteria for multiple sclerosis diagnosis in a large multicentre cohort of patients with CIS to provide evidence to guide revisions of multiple sclerosis diagnostic criteria.

METHODS

Brain and spinal cord MRI and optic nerve assessments from patients with typical CIS suggestive of multiple sclerosis done less than 3 months from clinical onset in eight European multiple sclerosis centres were included in this retrospective study. Eligible patients were 16-60 years, and had a first CIS suggestive of CNS demyelination and typical of relapsing-remitting multiple sclerosis, a complete neurological examination, a baseline brain and spinal cord MRI scan obtained less than 3 months from clinical onset, and a follow-up brain scan obtained less than 12 months from CIS onset. We recorded occurrence of a second clinical attack (clinically definite multiple sclerosis) at months 36 and 60. We evaluated MRI criteria performance for DIS, DIT, and DIS plus DIT with a time-dependent receiver operating characteristic curve analysis.

FINDINGS

Between June 16, 1995, and Jan 27, 2017, 571 patients with CIS were screened, of whom 368 met all study inclusion criteria. At the last evaluation (median 50·0 months [IQR 27·0-78·4]), 189 (51%) of 368 patients developed clinically definite multiple sclerosis. At 36 months, the two DIS criteria showed high sensitivity (2010 McDonald 0·91 [95% CI 0·85-0·94] and 2016 MAGNIMS 0·93 [0·88-0·96]), similar specificity (0·33 [0·25-0·42] and 0·32 [0·24-0·41]), and similar area under the curve values (AUC; 0·62 [0·57-0·67] and 0·63 [0·58-0·67]). Performance was not affected by inclusion of symptomatic lesions (sensitivity 0·92 [0·87-0·96], specificity 0·31 [0·23-0·40], AUC 0·62 [0·57-0·66]) or cortical lesions (sensitivity 0·92 [0·87-0·95], specificity 0·32 [0·24-0·41], AUC 0·62 [0·57-0·67]). Requirement of three periventricular lesions resulted in slightly lower sensitivity (0·85 [0·78-0·90], slightly higher specificity (0·40 [0·32-0·50], and similar AUC (0·63 [0·57-0·68]). Inclusion of optic nerve evaluation resulted in similar sensitivity (0·92 [0·87-0·96]), and slightly lower specificity (0·26 [0·18-0·34]) and AUC (0·59 [0·55-0·64]). AUC values were also similar for DIT (2010 McDonald 0·61 [0·55-0·67] and 2016 MAGNIMS 0·61 [0·55-0·66]) and DIS plus DIT (0·62 [0·56-0·67] and 0·64 [0·58-0·69]).

INTERPRETATION

The 2016 MAGNIMS criteria showed similar accuracy to the 2010 McDonald criteria in predicting the development of clinically definite multiple sclerosis. Inclusion of symptomatic lesions is expected to simplify the clinical use of MRI criteria without reducing accuracy, and our findings suggest that needing three lesions to define periventricular involvement might slightly increase specificity, suggesting that these two factors could be considered during further revisions of multiple sclerosis diagnostic criteria.

FUNDING

UK MS Society, National Institute for Health Research University College London Hospitals Biomedical Research Centre, Dutch MS Research Foundation.

Rapid, label-free identification of cerebellar structures using multiphoton microscopy

The cerebellum is the prominent laminar structure of the mammalian brain that has been implicated in various psychiatric and neurological diseases. Although clinical brain imaging techniques have provided precise anatomic images of cerebellar structures, a definitive diagnosis still requires adequate resolution to identify individual layers in cerebellar cortex, the extent of tumor, even requires the histological tissue examination during surgical procedures. In this study, multiphoton microscopy (MPM), based on second harmonic generation (SHG) and two-photon excited fluorescence (TPEF), was perform on the rat cerebellar structures and pathology with the combination of image analysis methods. Results show that MPM can reveal the cerebellar vermis, hemispheres, medulla, and ventricle, as well as axon bundles, Purkinje cells, capillaries, and the pia mater of the cerebellum. Together with custom-developed image processing algorithms, MPM could further differentiate between the gray and white matter, as well as evaluate the Purkinje cell layer, identify the cerebellar tumor boundary, and distinguish between the tumor core and peritumor regions. Our results establish a direct visualization and rapid assessment approach for the cerebellar structures, as well as suggest the feasibility of in vivo multiphoton microendoscopes and fiberscopes as clinical tools for neuropathological diagnoses.

Rapid, label-free identification of cerebellar structures using multiphoton microscopy

The cerebellum is the prominent laminar structure of the mammalian brain that has been implicated in various psychiatric and neurological diseases. Although clinical brain imaging techniques have provided precise anatomic images of cerebellar structures, a definitive diagnosis still requires adequate resolution to identify individual layers in cerebellar cortex, the extent of tumor, even requires the histological tissue examination during surgical procedures. In this study, multiphoton microscopy (MPM), based on second harmonic generation (SHG) and two-photon excited fluorescence (TPEF), was perform on the rat cerebellar structures and pathology with the combination of image analysis methods. Results show that MPM can reveal the cerebellar vermis, hemispheres, medulla, and ventricle, as well as axon bundles, Purkinje cells, capillaries, and the pia mater of the cerebellum. Together with custom-developed image processing algorithms, MPM could further differentiate between the gray and white matter, as well as evaluate the Purkinje cell layer, identify the cerebellar tumor boundary, and distinguish between the tumor core and peritumor regions. Our results establish a direct visualization and rapid assessment approach for the cerebellar structures, as well as suggest the feasibility of in vivo multiphoton microendoscopes and fiberscopes as clinical tools for neuropathological diagnoses.

[Degenerative cerebellar diseases and differential diagnoses]

CLINICAL/METHODICAL ISSUE

Cerebellar syndromes result in distinct clinical symptoms, such as ataxia, dysarthria, dysmetria, intention tremor and eye movement disorders.

STANDARD RADIOLOGICAL METHODS

In addition to the medical history and clinical examination, imaging is particularly important to differentiate other diseases, such as hydrocephalus and multi-infarct dementia from degenerative cerebellar diseases. Degenerative diseases with cerebellar involvement include Parkinson's disease, multiple system atrophy as well as other diseases including spinocerebellar ataxia.

ACHIEVEMENTS

In addition to magnetic resonance imaging (MRI), nuclear medicine imaging investigations are also helpful for the differentiation.

PRACTICAL RECOMMENDATIONS

Axial fluid-attenuated inversion recovery (FLAIR) and T2-weighted sequences can sometimes show a signal increase in the pons as a sign of degeneration of pontine neurons and transverse fibers in the basilar part of the pons. The imaging is particularly necessary to exclude other diseases, such as normal pressure hydrocephalus (NPH), multi-infarct dementia and cerebellar lesions.

Cerebellar Infarction Presenting with Acute Vestibular Syndrome in Two U.S. Air Force Pilots

BACKGROUND

Cerebellar infarction is an uncommon but serious cause of isolated acute vestibular symptoms, particularly in young, healthy individuals, and can easily be overlooked. We present two cases of cerebellar infarction in U.S. Air Force pilots, one of which occurred during flight.

CASE REPORTS

A 41-yr-old man developed acute vertigo, disequilibrium, nausea, and headache, with progressive slow symptomatic improvement, and presented to medical attention 4 d after symptom onset. Brain magnetic resonance imaging showed right inferomedial cerebellar infarction. Echocardiography discovered patent foramen ovale and atrial septal aneurysm. A 40-yr-old man developed severe vertigo, nausea, and vomiting during initial aircraft descent. Head computed tomography scan was performed acutely and was normal. Initial assessment was benign paroxysmal positional vertigo. Brain magnetic resonance imaging 1 mo after symptom onset showed a small right inferior cerebellar infarction. Patent foramen ovale and bilateral atrial enlargement were seen on echocardiography. Both pilots made full neurological recoveries and were eventually returned to flight status.

DISCUSSION

Central causes of isolated acute vestibular symptoms are uncommon and are often not considered in otherwise healthy individuals. Cerebellar infarction is one of these uncommon but increasingly recognized causes of acute vestibular symptoms. As evaluation and management of central causes are much different from peripheral conditions, prompt localization confirmation is paramount. Accurate evidence-based bedside screening methods are available for rapid localization. Awareness of the possibility of central etiologies and careful clinical evaluation with application of bedside screening methods in patients with acute vestibular symptoms will reduce the number of inaccurate diagnoses.Hesselbrock RR. Cerebellar infarction presenting with acute vestibular syndrome in two U.S. Air Force pilots. Aerosp Med Hum Perform. 2017; 88(9):880-883.