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Visual Hallucinations (VH) are a common non-motor symptom of Parkinson’s Disease (PD) and the Lewy body dementias (LBD) of Parkinson's disease with dementia (PDD) and Dementia with Lewy Bodies (DLB). The origin of VH in PD and LBD is debated: earlier studies considered a number of different possible mechanisms underlying VH including visual disorders, Rapid Eye Movement (REM) Sleep Intrusions, dysfunctions of top down or bottom up visual pathways, and neurotransmitter imbalance.

Background: Modafinil is primarily employed to treat narcolepsy but also as an off-label cognitive enhancer. Functional Magnetic Resonance Imaging (fMRI) studies indicate that modafinil modulates the connectivity of neocortical networks primarily involved in attention and executive functions. However, much less is known about the drug's effects on subcortical structures. Following preliminary findings, we evaluated modafinil's activity on the connectivity of distinct cerebellar regions with the neocortex. We assessed the spatial relationship of these effects with the expression of neurotransmitter receptors/transporters., Methods: Patterns of resting-state fMRI (rs-fMRI) connectivity were estimated in 50 participants from scans acquired pre- and post-administration of a single (100 mg) dose of modafinil (n=25) or placebo (n=25). Using specific cerebellar regions as seeds for voxel-wise analyses, we examined modafinil's modulation on cerebellar-neocortical connectivity. Next, we conducted a quantitative evaluation of the spatial overlap between the modulation of cerebellar-neocortical connectivity and the expression of neurotransmitter receptors/transporters obtained by publicly available databases., Results: Modafinil increased the connectivity of Crus I and Vermis IX with prefrontal regions. Crus I connectivity changes were associated with the expression of dopaminergic D 2 receptors. The Vermis I-II showed enhanced coupling with the dorsal anterior cingulate cortex and matched the expression of histaminergic H 3 receptors. The Vermis VII-VIII displayed increased connectivity with the visual cortex, an activity associated with dopaminergic and histaminergic neurotransmission., Conclusion: Our study reveals modafinil's modulatory effects on cerebellar-neocortical connectivity. The modulation mainly involves Crus I and the Vermis and spatially overlaps the distribution of dopaminergic and histaminergic receptors and serotonin transporters., (Copyright © 2024. Published by Elsevier Inc.)

Intravascular large B cell lymphoma (IVLBCL) is a very rare subtype of aggressive non-Hodgkin B cell lymphoma characterized by intravascular proliferation of clonal B lymphocytes, classically associated with pulmonary and cutaneous disease and, less frequently, with central nervous system (CNS) involvement. Brain imaging findings are usually non-specific, with evidence of multiple vascular occlusions and stroke as non-specific multifocal abnormalities. We present an exceptionally rare case of IVLBCL in a patient with unexplained inflammatory syndrome with B symptoms and rapidly progressive neurological impairment, with multifocal hemorrhagic and tumefactive brain lesions seen on MRI. We suggest that in this clinical setting, the presence of tumefactive and hemorrhagic lesions should raise suspicion for IVLBCL and lead to the decision to perform a biopsy, which, nonetheless, remains the diagnostic gold standard., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

We evaluated the accuracy of the quantitative and semiquantitative analysis in detecting regional atrophy patterns and differentiating mild cognitive impairment patients who remain stable (aMCI-S) from patients who develop Alzheimer's disease (aMCI-AD) at clinical follow-up. Baseline magnetic resonance imaging was used for quantitative and semiquantitative analysis using visual rating scales. Visual rating scores were related to gray matter thicknesses or volume measures of some structures belonging to the same brain regions. Receiver operating characteristic (ROC) analysis was performed to assess measures' accuracy in differentiating aMCI-S from aMCI-AD. Comparing aMCI-S and aMCI-AD patients, significant differences were found for specific rating scales, for cortical thickness belonging to the middle temporal lobe (MTL), anterior temporal (AT), and fronto-insular (FI) regions, for gray matter volumes belonging to MTL and AT regions. ROC curve analysis showed that middle temporal atrophy, AT, and FI visual scales showed better diagnostic accuracy than quantitative measures also when thickness measures were combined with hippocampal volumes. Semiquantitative evaluation, performed by trained observers, is a fast and reliable tool in differentiating, at the early stage of disease, aMCI patients that remain stable from those patients that may progress to AD since visual rating scales may be informative both about early hippocampal volume loss and cortical thickness reduction., Competing Interests: Conflict of interest: Cesare Colosimo declares that he is scientific consultant for Bracco Diagnostics Inc. and Bayer HealthCare. The other authors do not state the conflict of interest., (© 2022 Rosalinda Calandrelli et al., published by De Gruyter.)

The salience network (SN), ventral attention network (VAN), dorsal attention network (DAN) and default mode network (DMN) have shown significant interactions and overlapping functions in bottom-up and top-down mechanisms of attention. In the present study, we tested if the SN, VAN, DAN and DMN connectivity can infer the gestational age (GA) at birth in a study group of 88 healthy neonates, scanned at 40 weeks of post-menstrual age, and with GA at birth ranging from 28 to 40 weeks. We also ascertained whether the connectivity within each of the SN, VAN, DAN and DMN was able to infer the average functional connectivity of the others. The ability to infer GA at birth or another network's connectivity was evaluated using a multivariate data-driven framework. The VAN, DAN and the DMN inferred the GA at birth (p < 0.05). The SN, DMN and VAN were able to infer the average connectivity of the other networks (p < 0.05). Mediation analysis between VAN's and DAN's inference on GA at birth found reciprocal transmittance of change with GA at birth of VAN's and DAN's connectivity (p < 0.05). Our findings suggest that the VAN has a prominent role in bottom-up salience detection in early infancy and that the role of the VAN and the SN may overlap in the bottom-up control of attention., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

OBJECTIVE. The purpose of this article is to provide an illustrative review of nonsyndromic congenital causes of sensorineural hearing loss (SNHL) in children. CONCLUSION. Early recognition and treatment are essential in maximizing developmental outcomes in children with congenital SNHL. Because imaging plays an integral role in identifying underlying causes of SNHL, it is imperative that radiologists be able to recognize, describe, and appropriately categorize the spectrum of congenital inner ear malformations in children.

Cerebral peri-aneurysmal edema (PE) is typically associated with giant partially-thrombosed aneurysms and less frequently with smaller aneurysms treated with endovascular embolization. An understanding of the pathophysiologic mechanism of PE is still limited. We report 3 cases of cerebral aneurysms associated with PE. We describe 2 cases of giant partially thrombosed aneurysms surrounded by vasogenic edema with apposition of an intramural and juxtamural thrombus. Our third case is a smaller aneurysm inciting vasogenic edema several years after coil embolization. Vessel-wall magnetic resonance imaging (MRI) showed avid wall enhancement and an enhancing thrombus embedded within the coils, reflecting inflammation of the aneurysm wall and proliferation of the vasa vasorum. Thrombosis within the aneurysmal sac and walls, both in native and treated aneurysms, may promote inflammatory changes and sustain the occurrence of PE. Vessel-wall MRI has a potential role in the evaluation process of this subgroup of aneurysms.

Purpose: Although symptoms are expected to improve after the resection of pituitary macroadenomas, tumor resection volume does not always correlate with the patient's symptoms. Our objectives were to assess the pre and postoperative volumes of pituitary macroadenomas before, immediately after surgery and at follow-up, and to explore possible associations and correlations among these changes and symptoms., Materials and Methods: We retrospectively reviewed the clinical records and the preoperative and postoperative magnetic resonance imaging studies at 24 hours and at 3, 6 and 9 months follow-up of 146 patients who underwent surgery for pituitary macroadenomas. We measured tumor volumes before and after surgery and compared changes with symptom improvement., Results: The mean preoperative tumor volume was 24.66 cm 3 (standard deviation 65.18 cm 3 , 95% confidence interval (CI) 14-35.32). The most common symptoms were visual/cranial nerve abnormalities (65%) and headaches (56%). Immediately after surgery, symptoms persisted without significant changes in all patients. A progressive tumor volume decrease was noted during follow-up, and symptoms improved in 78% of patients. Despite no imaging evidence of chiasm or cavernous sinus compression, 32 patients showed no symptom improvement. Patients with symptoms for more than 1 year (mean duration of symptoms 26 months, SD 24.3, 95% CI 22.03-29.97 months) had a higher risk of the persistence of symptoms compared to patients with a mean duration of symptoms of less than 1 year (odds ratio 2.5, 95% CI 2.4-3, P < 0.005)., Conclusions: The duration of symptoms prior of surgery is a more important factor than tumor resection volume alone when considering the long-term outcome of symptoms. Furthermore, lack of symptom improvement in the immediate postoperative period does not necessarily represent an inadequate resection.

Background and Purpose: Cavitary plaques have been reported as a manifestation of otospongiosis. They have been related to third window manifestations, complications during cochlear implantation, and sensorineural hearing loss. However, their etiology and clinical implications are not entirely understood. Our purpose was to determine the prevalence, imaging findings, and clinical implications of cavitary plaques in otospongiosis., Materials and Methods: We identified patients with otospongiosis at a tertiary care academic medical center from January 2012 to April 2017. Cross-sectional CT images and clinical records of 47 patients (89 temporal bones) were evaluated for the presence, location, and imaging features of cavitary and noncavitary otospongiotic plaques, as well as clinical symptoms and complications in those who underwent cochlear implantation., Results: Noncavitary otospongiotic plaques were present in 86 (97%) temporal bones and cavitary plaques in 30 (35%). Cavitary plaques predominated with increasing age (mean age, 59 years; P = .058), mostly involving the anteroinferior wall of the internal auditory canal ( P = .003), and their presence was not associated with a higher grade of otospongiosis by imaging ( P = .664) or with a specific type of hearing loss ( P = .365). No patients with cavitary plaques had third window manifestations, and those with a history of cochlear implantation ( n = 6) did not have complications during the procedure., Conclusions: Cavitary plaques occurred in one-third of patients with otospongiosis. Typically, they occurred in the anteroinferior wall of the internal auditory canal. There was no correlation with the degree of otospongiosis, type of hearing loss, or surgical complications. Cavitary plaques tended to present in older patients., (© 2018 by American Journal of Neuroradiology.)

Psychosis in Parkinson's disease (PD) is currently considered as the occurrence of hallucinations and delusions. The historical meaning of the term psychosis was, however, broader, encompassing a disorganization of both consciousness and personality, including behavior abnormalities, such as impulsive overactivity and catatonia, in complete definitions by the International Classification of Diseases-10 (ICD-10) and the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition ( DSM-5 ). Our review is aimed at reminding that complex psychotic symptoms, including impulsive overactivity and somatoform disorders (the last being a recent controversial entity in PD), were carefully described in postencephalitic parkinsonism (PEP), many decades before dopaminergic treatment era, and are now described in other parkinsonisms than PD. Eminent neuropsychiatrists of the past century speculated that studying psychosis in PEP might highlight its mechanisms in other conditions. Yet, functional assessments were unavailable at the time. Therefore, the second part of our article reviews the studies of neural correlates of psychosis in parkinsonisms, by taking into account both theories on the narrative functions of the default mode network (DMN) and hypotheses on DMN modulation., Competing Interests: Disclosure The authors report no conflicts of interest in this work.

Brain imaging plays an important role in the study of Alzheimer's disease (AD), where atrophy has been found to occur in the hippocampal formation during the very early disease stages and to progress in parallel with the disease's evolution. The aim of the present study was to evaluate a possible correlation between "Small World" characteristics of the brain connectivity architecture-as extracted from EEG recordings-and hippocampal volume in AD patients. A dataset of 144 subjects, including 110 AD (MMSE 21.3) and 34 healthy Nold (MMSE 29.8) individuals, was evaluated. Weighted and undirected networks were built by the eLORETA solutions of the cortical sources' activities moving from EEG recordings. The evaluation of the hippocampal volume was carried out on a subgroup of 60 AD patients who received a high-resolution T1-weighted sequence and underwent processing for surface-based cortex reconstruction and volumetric segmentation using the Freesurfer image analysis software. Results showed that, quantitatively, more correlation was observed in the right hemisphere, but the same trend was seen in both hemispheres. Alpha band connectivity was negatively correlated, while slow (delta) and fast-frequency (beta, gamma) bands positively correlated with hippocampal volume. Namely, the larger the hippocampal volume, the lower the alpha and the higher the delta, beta, and gamma Small World characteristics of connectivity. Accordingly, the Small World connectivity pattern could represent a functional counterpart of structural hippocampal atrophying and related-network disconnection.

Intracranial dissecting aneurysms have been frequently reported to present with fairly challenging and time-variable imaging findings that can be mostly explained by the pathological mechanisms that underline the dissection. We present two cases of spontaneous dissecting aneurysm of the supraclinoid ICA, both clinically presenting with SAH, but characterized by different progression of clinical symptoms and imaging. However, in both cases an outpouch and a mild fusiform dilation of the supraclinoid ICA was present in the initial CTA performed after the occurrence of symptoms. These findings were well depicted by the MPR reformats performed retrospectively. We postulate that this finding may represent the point of initial transmural dissection and we recommend that careful analysis of the CTA MRP reformatted images should be performed in order to detect this finding promptly., (© The Author(s) 2016.)

The Medio-Dorsal Nuclei (MDN) including the thalamic magnocellular and parvocellular thalamic regions has been implicated in verbal memory function. In a 77 year old lady, with a prior history of a clinically silent infarct of the left MDN, we observed the acute onset of spontaneous confabulations when an isolated new infarct occurred in the right MDN. The patient and five age-matched healthy subjects underwent Magnetic Resonance Imaging (MRI) and Diffusion Tensor Imaging (DTI). The thalamic lesions were localized by overlapping Morel Thalamic Atlas with structural MRI data. DTI was used to assess: i) white matter alterations (Fractional Anisotropy, FA) within fibers connecting the ischemic areas to cortex; ii) the micro-structural damage (Mean Diffusivity) within the thalamic sub-regions defined by their structural connectivity to the Anterior Cingulate Cortex (ACC) and to the temporal lobes. These target regions were chosen because their damage is considered associated with the appearance of confabulations. Thalamic lesions were localized within the parvocellular regions of the right and left MDNs. The structural connectivity study showed that the fiber tracts, connecting the bilaterally damaged thalamic regions with the frontal cortex, corresponded to the anterior thalamic radiations (ATR). FA within these tracts was significantly lower in the patient as compared to controls. Mean diffusivity within the MDNs projecting to Broadman area (BA) 24, BA25 and BA32 of ACC was significantly higher in the patient than in control group. Mean diffusivity values within the MDN projecting to temporal lobes in contrast were not different between patient and controls. Our findings suggest the involvement of bilateral MDNs projections to ACC in the genesis of confabulations and help provide clarity to the longstanding debate on the origin of confabulations.

Levitation and tentacular movements (LTM) are considered specific, yet rare (30%), features of Corticobasal Syndrome (CBS), and are erroneously classified as alien hand. Our study focuses on these typical involuntary movements and aims to highlight possible neural correlates.LTM were recognizable during functional magnetic resonance imaging (fMRI) in 4 of 19 CBS patients. FMRI activity was evaluated with an activation recognition program for movements, during LTM, consisting of levitaton and finger writhing, and compared with the absence of movement (rest) and voluntary movements (VM), similar to LTM, of affected and unaffected arm-hand. FMRI acquisition blocks were balanced in order to match LTM blocks with rest and VM conditions. In 1 of the 4 patients, fMRI was acquired only during LTM and with a different equipment.Despite variable intensity and range of involuntary movements, evidenced by videos, fMRI showed, during LTM, a significant (P<0.05-0.001) activation only of the contralateral primary motor cortex (M1). Voluntary movements of the affected and unaffected arm elicited the known network including frontal, supplementary, sensory-motor cortex, and cerebellum. Willed movements of the LTM-affected arm induced higher and wider activation of contralateral M1 compared with the unaffected arm.The isolated activation of M1 suggests that LTM is a cortical disinhibition symptom, not involving a network. Higher activation of M1 during VM confirms that M1 excitability changes occur in CBS. Our study calls, finally, attention to the necessity to separate LTM from other alien hand phenomena.

Visual Hallucinations (VH) are a common non-motor symptom of Parkinson's Disease (PD) and the Lewy body dementias (LBD) of Parkinson's disease with dementia (PDD) and Dementia with Lewy Bodies (DLB). The origin of VH in PD and LBD is debated: earlier studies considered a number of different possible mechanisms underlying VH including visual disorders, Rapid Eye Movement (REM) Sleep Intrusions, dysfunctions of top down or bottom up visual pathways, and neurotransmitter imbalance. More recently newer hypotheses introduce, among the possible mechanisms of VH, the role of attention networks (ventral and dorsal) and of the Default Mode Network (DMN) a network that is inhibited during attentional tasks and becomes active during rest and self referential imagery. Persistent DMN activity during active tasks with dysfunctional imbalance of dorsal and ventral attentional networks represents a new hypothesis on the mechanism of VH. We review the different methods used to classify VH and discuss reports supporting or challenging the different hypothetical mechanisms of VH.

Background: Autoscopic phenomena are psychic illusory visual experiences consisting of the perception of the image of one's own body or face within space, either from an internal point of view, as in a mirror or from an external point of view. Descriptions based on phenomenological criteria distinguish six types of autoscopic experiences: autoscopic hallucination, he-autoscopy or heautoscopic proper, feeling of a presence, out of body experience, negative and inner forms of autoscopy., Methods and Results: We report a case of a patient with he-autoscopic seizures. EEG recordings during the autoscopic experience showed a right parietal epileptic focus. This finding confirms the involvement of the temporo-parietal junction in the abnormal body perception during autoscopic phenomena. We discuss and review previous literature on the topic, as different localization of cortical areas are reported suggesting that out of body experience is generated in the right hemisphere while he-autoscopy involves left hemisphere structures.

Aims of the Study: Earlier P300 studies were conducted when the prevalence of dementia with Lewy Bodies (DLB) was unknown. Our study aims to examine whether P300 abnormalities are present in DLB and to evidence possible differences between DLB and Alzheimer's disease (AD). A second aim of this study is to look for correlations between P300 recordings and EEG, as abnormal EEG variability has been described in DLB., Patients and Methods: Auditory P300 responses were recorded by a classic oddball paradigm in 50 controls, in 36 DLB patients, and in 40 AD patients with MMSE>20., Results: Reliable auditory P300 responses were obtained in 26 DLB (72%), 33 AD (82.5%), and 46 controls (92%). P300 was more delayed and had lower amplitude in DLB compared to AD groups. P300 topography was also different as the anterior-to-posterior scalp amplitude gradient was reversed in DLB. P300 latency correlated with neuropsychological test scores and with EEG variables. Gradient inversion and delayed P300 responses in frontal derivations evidenced differences between DLB and AD patients with a sensitivity of 70% and a specificity of 97%., Conclusions: P300 recordings are abnormal in DLB and can be useful to distinguish DLB from AD., (Copyright © 2010 Elsevier Masson SAS. All rights reserved.)

We present two further cases of the pharyngeal-cervical-brachial (PCB) form of GBS, with unfavourable outcome, showing dramatic dissociation between upper and lower body Symptoms. Both patients showed rapidly progressive motor denervation with disappearance of Compound Muscle Action Potentials (CMAPs) in upper limbs muscles. Sensory Nerve Action Potentials (SNAPs) were instead normal. Normal reflexes, F waves and action potentials were elicited in lower limbs. Despite i.v. Immunoglobulin treatment no recovery was observed and both patients died within a year from onset of symptoms.