Case 318.

HISTORY: A 72-year-old man sought care for a cognitive deterioration over the past 5 years. There was a documented decline in his performance on the Mini-Mental State Examination (30 of 30 in 2016, 23 of 30 in 2021), with mainly episodic memory impairment. A more detailed history revealed a gait problem, paresthesia in both feet, and nocturnal urinary frequency. Clinical examination findings were suggestive of a length-dependent polyneuropathy. In addition, a right-sided Babinski sign was noted. Electromyography and a nerve conduction study corroborated a peripheral axonal sensorimotor neuropathy. MRI of the brain was performed (Figure).

Case 318: Adult Polyglucosan Body Disease.

HISTORY: A 72-year-old man sought care for a cognitive deterioration over the past 5 years. There was a documented decline in his performance on the Mini-Mental State Examination (30 of 30 in 2016, 23 of 30 in 2021), with mainly episodic memory impairment. A more detailed history revealed a gait problem, paresthesia in both feet, and nocturnal urinary frequency. Clinical examination findings were suggestive of a length-dependent polyneuropathy. In addition, a right-sided Babinski sign was noted. Electromyography and a nerve conduction study corroborated a peripheral axonal sensorimotor neuropathy. MRI of the brain was performed.

MRI Analysis Of the Water Content Change In the Brain During Acute Ethanol Consumption Via Quantitative Water Mapping.

AIMS: Alcohol consumption influences the water balance in the brain. While the impact of chronic alcohol misuse on cerebral water content has been the subject of several studies, less is known about the effects of acute alcohol misuse, with contradictory results in the literature. Therefore, we investigated the effects of acute alcohol intoxication on cerebral water content using a precise quantitative magnetic resonance imaging (MRI) sequence. METHODS: In a prospective study, we measured cerebral water content in 20 healthy volunteers before alcohol consumption and after reaching a breath alcohol concentration of 1 ‰. A quantitative MRI water mapping sequence was conducted on a clinical 3 T system. Non-alcoholic fluid input and output were documented and accounted for. Water content was assessed for whole brain, grey and white matter and more specifically for regions known to be affected by acute or chronic alcohol misuse (occipital and frontal lobes, thalamus and pons). Changes in the volume of grey and white matter as well as the whole brain were examined. RESULTS: Quantitative cerebral water content before and after acute alcohol consumption did not differ significantly (P ≥ 0.07), with changes often being within the range of measurement accuracy. Whole brain, white and grey matter volume did not change significantly (P ≥ 0.12). CONCLUSION: The results of our study show no significant water content or volume change in the brain after recent alcohol intake in healthy volunteers. This accounts for the whole brain, grey and white matter, occipital and frontal lobes, thalamus and pons.

True First-Pass Effect.

Background and Purpose- It has been hypothesized that in stroke patients, complete reperfusion (modified Thrombolysis in Cerebral Infarction; mTICI 3) after a single thrombectomy pass is a predictor for favorable outcome (modified Rankin Scale score, 0-2), but a true first-pass effect defined as improved clinical outcome after complete reperfusion with one versus multiple passes has not yet been specifically addressed in the literature. Methods- We compared clinical outcome of 164 consecutive patients with occlusions in the anterior circulation and known symptom onset, in whom we achieved complete reperfusion (mTICI 3), depending on whether complete reperfusion was achieved after a single thrombectomy pass (n=62) or multiple thrombectomy passes (n=102). To adjust for confounding factors such as prolonged time spans between symptom onset and reperfusion, additional administration of intra-arterial thrombolysis, and clot localization, we also compared clinical outcome of our first-pass group with a matched cohort (n=54) and a superselective subgroup of first-pass patients (only M1 occlusions, no additional intra-arterial thrombolysis; n=46) with its matched cohort (n=24). Results- Multivariable analysis of our cohort of 164 nonmatched patients revealed that there was a significant association between first-pass complete reperfusion and favorable clinical outcome (P=0.013). This was confirmed in our case-control analyses (P=0.010 and P=0.042). In our matched cohorts, favorable clinical outcome was seen almost twice as often if complete reperfusion was achieved after one pass (62% and 67% versus 36% and 37%), and odds for favorable outcome were 2.4 to 3.2× higher (CIs, 1.1-4.8 and 1.0-9.9). Conclusions- First-pass complete reperfusion is an independent factor for favorable outcome and should be aimed for in mechanical thrombectomy.

Presence of the posterior pituitary bright spot sign on MRI in the general population: a comparison between 1.5 and 3T MRI and between 2D-T1 spin-echo- and 3D-T1 gradient-echo sequences.

PURPOSE: To describe the prevalence of the posterior pituitary bright spot (PPBS) in the general population on 1.5 and 3T MRI examinations and on 2D-T1 spin-echo (SE) and 3D-T1 gradient-echo (GE) sequences. MATERIALS AND METHODS: 1017 subjects who received an MRI of the brain for aspecific neurological complaints were included. MRI was performed on 1.5T in 64.5% and on 3T in 35.5% of subjects. Presence of the PPBS was evaluated on sagittal 2D T1-SE echo images with slice thickness 3 mm in 67.5% and on sagittal 3D T1-GE with slice thickness 0.9 mm in 32.5% of subjects. RESULTS: The PPBS was detectable in 95.9% of subjects. After correction for sex and age, no statistically significant difference could be seen concerning PPBS detection between 1.5 and 3T MRI examinations (p = 0.533), nor between 2D T1-SE and 3D T1-GE sequences (p = 0.217). There was a statistically significant association between increasing age and the absence of the PPBS (p < 0.001). The PPBS could not be identified in 6.2% of male subjects, compared to 2.2% of female subjects (p = 0.01). DISCUSSION: Absence of the PPBS can be seen in 4.1% of patients undergoing MRI of the brain for non-endocrinological reasons. Neither field-strength nor the use of a thick-sliced 2D T1-SE versus a thin-sliced 3D T1-GE sequence influenced the detectability of the PPBS. There is a statistically significant association between increasing age and male sex and the absence of the PPBS.

Infarct fogging on immediate postinterventional CT-a not infrequent occurrence.

PURPOSE: A pseudo-normalization of infarcted brain parenchyma, similar to the "fogging effect" which usually occurs after 2-3 weeks, can be observed on CT performed immediately after endovascular stroke treatment (EST). Goal of this study was to analyze the incidence of this phenomenon and its evolution on follow-up imaging. METHODS: One hundred fifty-two patients in our database of 949 patients, who were treated for acute stroke between January 2010 and January 2015, fulfilled the inclusion criteria of (a) EST for an acute stroke in the anterior circulation, (b) an ASPECT-score < 10 on pre-interventional CT, and (c) postinterventional CT imaging within 4.5 h after the procedure. Two independent reviewers analyzed imaging data of these patients. RESULTS: Transformation of brain areas from hypoattenuated on pre-interventional CT to isodense on postinterventional CT was seen in 37 patients in a total of 49 ASPECTS areas (Cohen's kappa 0.819; p < 0.001). In 17 patients, the previously hypoattenuated brain areas became isodense, but appeared swollen. In 20 patients (13%), the previously hypodense brain area could not be distinguished from normal brain parenchyma. On follow-up imaging, all isodense brain areas showed signs of infarction. CONCLUSION: Pseudo-normalization of infarct hypoattenuation on postinterventional CT is not infrequent. It is most likely caused by contrast leakage in infarcted parenchyma and does not represent salvage of ischemic brain parenchyma.

Imaging Findings in Acute Traumatic Brain Injury: a National Institute of Neurological Disorders and Stroke Common Data Element-Based Pictorial Review and Analysis of Over 4000 Admission Brain Computed Tomography Scans from the Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI) Study.

In 2010, the National Institute of Neurological Disorders and Stroke (NINDS) created a set of common data elements (CDEs) to help standardize the assessment and reporting of imaging findings in traumatic brain injury (TBI). However, as opposed to other standardized radiology reporting systems, a visual overview and data to support the proposed standardized lexicon are lacking. We used over 4000 admission computed tomography (CT) scans of patients with TBI from the Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI) study to develop an extensive pictorial overview of the NINDS TBI CDEs, with visual examples and background information on individual pathoanatomical lesion types, up to the level of supplemental and emerging information (e.g., location and estimated volumes). We documented the frequency of lesion occurrence, aiming to quantify the relative importance of different CDEs for characterizing TBI, and performed a critical appraisal of our experience with the intent to inform updating of the CDEs. In addition, we investigated the co-occurrence and clustering of lesion types and the distribution of six CT classification systems. The median age of the 4087 patients in our dataset was 50 years (interquartile range, 29-66; range, 0-96), including 238 patients under 18 years old (5.8%). Traumatic subarachnoid hemorrhage (45.3%), skull fractures (37.4%), contusions (31.3%), and acute subdural hematoma (28.9%) were the most frequently occurring CT findings in acute TBI. The ranking of these lesions was the same in patients with mild TBI (baseline Glasgow Coma Scale [GCS] score 13-15) compared with those with moderate-severe TBI (baseline GCS score 3-12), but the frequency of occurrence was up to three times higher in moderate-severe TBI. In most TBI patients with CT abnormalities, there was co-occurrence and clustering of different lesion types, with significant differences between mild and moderate-severe TBI patients. More specifically, lesion patterns were more complex in moderate-severe TBI patients, with more co-existing lesions and more frequent signs of mass effect. These patients also had higher and more heterogeneous CT score distributions, associated with worse predicted outcomes. The critical appraisal of the NINDS CDEs was highly positive, but revealed that full assessment can be time consuming, that some CDEs had very low frequencies, and identified a few redundancies and ambiguity in some definitions. Whilst primarily developed for research, implementation of CDE templates for use in clinical practice is advocated, but this will require development of an abbreviated version. In conclusion, with this study, we provide an educational resource for clinicians and researchers to help assess, characterize, and report the vast and complex spectrum of imaging findings in patients with TBI. Our data provides a comprehensive overview of the contemporary landscape of TBI imaging pathology in Europe, and the findings can serve as empirical evidence for updating the current NINDS radiologic CDEs to version 3.0.

Adjuvant Wilms' tumour 1-specific dendritic cell immunotherapy complementing conventional therapy for paediatric patients with high-grade glioma and diffuse intrinsic pontine glioma: protocol of a monocentric phase I/II clinical trial in Belgium.

INTRODUCTION: Diffuse intrinsic pontine glioma (DIPG) and paediatric high-grade glioma (pHGG) are aggressive glial tumours, for which conventional treatment modalities fall short. Dendritic cell (DC)-based immunotherapy is being investigated as a promising and safe adjuvant therapy. The Wilms' tumour protein (WT1) is a potent target for this type of antigen-specific immunotherapy and is overexpressed in DIPG and pHGG. Based on this, we designed a non-randomised phase I/II trial, assessing the feasibility and safety of WT1 mRNA-loaded DC (WT1/DC) immunotherapy in combination with conventional treatment in pHGG and DIPG. METHODS AND ANALYSIS: 10 paediatric patients with newly diagnosed or pretreated HGG or DIPG were treated according to the trial protocol. The trial protocol consists of leukapheresis of mononuclear cells, the manufacturing of autologous WT1/DC vaccines and the combination of WT1/DC-vaccine immunotherapy with conventional antiglioma treatment. In newly diagnosed patients, this comprises chemoradiation (oral temozolomide 90 mg/m2 daily+radiotherapy 54 Gy in 1.8 Gy fractions) followed by three induction WT1/DC vaccines (8-10×106 cells/vaccine) given on a weekly basis and a chemoimmunotherapy booster phase consisting of six 28-day cycles of oral temozolomide (150-200 mg/m2 on days 1-5) and a WT1/DC vaccine on day 21. In pretreated patients, the induction and booster phase are combined with best possible antiglioma treatment at hand. Primary objectives are to assess the feasibility of the production of mRNA-electroporated WT1/DC vaccines in this patient population and to assess the safety and feasibility of combining conventional antiglioma treatment with the proposed immunotherapy. Secondary objectives are to investigate in vivo immunogenicity of WT1/DC vaccination and to assess disease-specific and general quality of life. ETHICS AND DISSEMINATION: The ethics committee of the Antwerp University Hospital and the University of Antwerp granted ethics approval. Results of the clinical trial will be shared through publication in a peer-reviewed journal and presentations at conferences. TRIAL REGISTRATION NUMBER: NCT04911621.

The Claustrum Sign in Febrile Infection-Related Epilepsy Syndrome (FIRES).

Teaching Point: Bilateral mesiotemporal edema and the claustrum sign can be seen in febrile infection-related epilepsy syndrome (FIRES) and new onset refractory status epilepticus (NORSE) but are neither diagnostic nor pathognomonic for these entities.

Anything but Little: a Pictorial Review on Anatomy and Pathology of the Cerebellum.

Despite its small size the cerebellum is an anatomically complex and functionally important part of the brain. Traditionally the cerebellum is viewed as a motor control structure entirely devoted to motor control and learning, but recent functional magnetic resonance imaging (fMRI) studies demonstrated significant involvement of the cerebellum in higher order cognitive functions. The anatomical complexity of the cerebellum is reflected by the several nomenclature systems that exist for the description of cerebellar anatomy. The cerebellum can be affected by a variety of pathological processes, including congenital, infectious and inflammatory, neoplastic, vascular, degenerative and toxic metabolic diseases. The purpose of this pictorial review is to (1) provide a general overview of cerebellar anatomy and function, (2) demonstrate normal cerebellar anatomy on imaging studies, and (3) illustrate both common as well as rare pathological conditions affecting the cerebellum.

COMBINED CENTRAL RETINAL ARTERIAL AND VENOUS OCCLUSIONS DUE TO LEUKEMIC INFILTRATION.

PURPOSE: To report combined central arterial and venous occlusions secondary to bilateral leukemic interfascicular optic nerve infiltration in a 56-year-old man. This was the sole presentation of a relapse in T/myeloid mixed-phenotype acute leukemia after 5 months of remission. METHODS: Case report with clinical photography. RESULTS: A 56-year-old man reported to be in complete remission of T/myeloid mixed-phenotype acute leukemia presented with sudden painless loss of vision in his left eye. Fundoscopy showed unilateral severe optic disk swelling with characteristic findings of a central retinal vein occlusion, namely, intraretinal and preretinal hemorrhages and cotton-wool spots, as well as the features of a central retinal artery occlusion resulting in a pale, edematous retina and a characteristic cherry-red spot. Blood analysis, cerebrospinal fluid evaluation, and bone marrow analysis were performed in combination with medical imaging. No evidence of leukemic relapse was found. An optic nerve biopsy was indicated because of decompensation of the contralateral eye and ultimately confirmed leukemic infiltration. CONCLUSION: Regardless of no hematological and nonspecific imaging findings, optic nerve biopsy may be crucial for clinical decision-making in a patient with acute complete vision loss and a history of leukemia.

Distinct features in adult polyglucosan body disease: a case series.

Adult polyglucosan body disease (APBD) is caused by bi-allelic pathogenic variants in GBE1 and typically shows middle age onset urinary symptoms followed by progressive gait disturbances and possibly cognitive decline. Here we present a Belgian cohort of four patients from three families showing both classical and atypical signs of APBD. By clinical phenotyping, detailed neuroimaging of both central nervous system and skeletal muscle, genetic and biochemical testing, we confront our findings with the classical presentation of adult polyglucosan body disease and emphasize the importance of a multidisciplinary approach when diagnosing these patients.

Not Your Everyday FCD: Imaging Findings of Focal Cortical Dysplasia Type 1.

Teaching Point: The imaging findings of focal cortical dysplasia type 1 are less well-known than focal cortical dysplasia type 2 and consist of increased white matter signal intensity and blurring of the gray-white matter in a large region of the brain, with associated segmental or lobar brain atrophy.

The Dark Pituitary: Hemochromatosis as a Lesser-Known Cause of Pituitary Dysfunction.

Teaching Point: Iron deposition in the pituitary gland in patients with primary and secondary hemochromatosis is a lesser-known cause of pituitary dysfunction and results in T2- and T2*-signal loss on MRI, other brain structures, in which iron deposition can be seen, are the choroid plexus and sporadically the circumventricular organs (e.g., the pineal gland).

Human Herpesvirus-6 Encephalitis.

Teaching point: HHV6 encephalitis is a specific complication to be considered in a patient with neurological symptoms after hematopoietic stem cell transplantation and typically shows symmetrical involvement of the limbic system.

Dorsal Arachnoid Web: A Rare Cause of Myelopathy.

Teaching point: The scalpel sign is pathognomonic for a dorsal arachnoid web, a rare clinical-radiologic entity that can cause myelopathy.

Alexander Disease.

Main teaching point: The main differential diagnosis of leukodystrophy associated with macrocephaly consists of Alexander disease, Canavan disease, and megalencephalic leukodystrophy with subcortical cysts. Distinguishing imaging characteristics of Alexander disease are an apicoposterior gradient of white matter involvement and a periventricular T2-hypointense rim.

Emergency Carotid Endarterectomy Instead of Carotid Artery Stenting Reduces Delayed Hemorrhage in Thrombectomy Stroke Patients.

PURPOSE: Data in the literature suggest that thrombectomy with emergency carotid artery stenting (CAS) in acute stroke is associated with an increased hemorrhage rate. As we perform thrombectomy with the patient under general anesthesia, we avoid emergency CAS and perform emergency carotid endarterectomy (CEA) as an alternative to CAS in the same anesthesia session in our angiography suite whenever needed and possible. METHODS: We compared 27 thrombectomy patients with emergency CEA and 62 thrombectomy patients with emergency CAS and glycoprotein (Gp) IIb/IIIa inhibitors and/or dual antiplatelet therapy (DAPT) in the same time span. RESULTS: The symptomatic hemorrhage rate was 0% (0/27) in the CEA group and 8% (5/62) in the CAS group (p = 0.317). The parenchymal hemorrhage rate (PH2) was 7% (2/27) in the CEA group and 16% (10/62) in the CAS group (p = 0.333). Both cases of PH2 in the CEA group occurred during the intervention and were diagnosed on immediate postinterventional imaging, whereas in the CAS group only 2/10 cases of PH2 occurred during the intervention and the remaining 8 PH2 occurred within 3 days after the intervention (p = 0.048). Clinical outcome at 90 days was comparable with 39% of CEA and 51% of CAS patients achieving good clinical outcome (modified Rankin scale, mRS 0-2, p = 0.452). CONCLUSION: The use of CEA is a feasible alternative to CAS in acute stroke and has the advantage that DAPT/GpIIb/IIIa inhibitors are not needed. All PH2 in CEA patients occurred during the intervention, implying that hemorrhage in this group is likely to be caused by reperfusion injury, whereas delayed hemorrhage is likely to be caused by DAPT/GpIIb/IIIa inhibitors.