Search

Background: Susac syndrome is a rare autoimmune endotheliopathy that affects the central nervous system, retina, and inner ear, characterized by encephalopathy, branch retinal artery occlusions, and sensorineural hearing loss. Due to the heterogeneity of its presentation, early diagnosis, and treatment remain challenging., Objective/methods: To evaluate the clinical outcomes and radiological responses in two patients with Susac syndrome treated with natalizumab in an off-label therapeutic approach, clinical assessments and serial magnetic resonance imaging (MRI) were performed over a follow-up period of up to 22 months to monitor disease progression and treatment response., Results: Both patients demonstrated clinical stabilization with reduced MRI and retinal angiography disease activity. Treatment was well tolerated, and no significant adverse events were reported during observation., Discussion: Natalizumab may constitute a potential off-label therapeutic for Susac syndrome. Further studies are warranted to assess its efficacy and safety in this rare condition., (© 2025 The Author(s). European Journal of Neurology published by John Wiley & Sons Ltd on behalf of European Academy of Neurology.)

Its angular representation on the retina does not solely determine the perceived size of an object. Instead, contextual information is interpreted. We investigated the levels of processing at which this interpretation occurs. Combining three experimental paradigms, we explored whether masked and more implicitly coded objects are already size-rescaled. We induced object size rescaling using a modified variant of the Ebbinghaus illusion. In this variant, six dots altered the size of a central stimulus and served as inducers generating Object-Substitution Masking (OSM). Participants reported the average size of multiple circles using the size-averaging paradigm, allowing us to test the contribution of masked and non-masked central target circles. Our Ebbinghaus illusion variant altered perceived stimulus size and showed robust masking via OSM. Furthermore, size-averaging was sensitive enough to detect perceived size changes in the magnitude of the ones induced by the Ebbinghaus illusion. Finally, combining all three paradigms, we observed that masked and non-masked stimuli contributed to size averaging in a size-rescaled manner. In a control experiment testing the general effects of Ebbinghaus inducers, we observed a contrast-like effect on size averaging. Large inducers decreased the perceived average size, while small inducers increased it. In summary, our experiments indicate that context integration, induced by the Ebbinghaus illusion, alters size representations at an early stage. These modified size representations are independent of whether a target is recognisable. Moreover, perceived average size appears to be coded relative to surrounding perceptual groups., Competing Interests: Declaration of competing interest The authors declare no competing interests., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: Isolated REM sleep behavior disorder (iRBD) indicates an early α-synucleinopathy with approximately 90% of individuals pheno-converting to Parkinson's disease (PD), dementia with Lewy bodies (DLB), or multiple system atrophy (MSA). Recently, prodromal disease definitions (pPD, pDLB, pMSA) have been introduced., Objective: To investigate the overlap of prodromal definitions in an established iRBD cohort., Methods: We applied the current diagnostic criteria for pPD, pDLB, and pMSA to N = 55 individuals from the local iRBD cohort., Results: All except two individuals fulfilled at least one of the prodromal disease definitions; most individuals were classified as pPD (94.5%). 56% of the individuals fulfilled more than one definition: 32.7% pMSA&pPD, 10.9% pDLB&pPD, and 12.7% all three (pPD&pDLB&pMSA). The cognitive screening [(pPD = pMSA) > pDLB], motor symptoms [pPD < (pDLB = pMSA)], and olfactory testing [(pPD = pDLB) < pMSA] significantly differed between groups., Conclusions: The observed overlap leads to challenges in patient counseling and risk disclosure. Better discrimination will facilitate research in early α-synucleinopathy phases., (© 2025 The Author(s). Movement Disorders Clinical Practice published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.)

Isolated rapid eye movement (REM) sleep behavior disorder (iRBD) highlights an early α-synucleinopathy. This study compared health-related quality of life (hrQoL) in 62 individuals with iRBD with 19 healthy controls (HC) and 29 individuals with Parkinson's disease (PD) and identified factors linked to poorer hrQoL. HrQoL was significantly lower in individuals with iRBD (83.33 ± 16.96) compared to HC (92.29 ± 5.49, p = 0.027). Poorer hrQoL in individuals with iRBD was linked to severity of multiple non-motor symptoms, most prominently fatigue and depressive symptoms being significant predictors ( p  < 0.001, adjusted R 2  = 0.81). This study highlights the importance of non-motor symptoms for hrQoL in prodromal PD., Competing Interests: Declaration of conflicting interestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background: Nitrous oxide (N₂O), commonly known as laughing gas, is widely recognized for its anesthetic and analgesic effects, and is frequently used in medical contexts. However, its misuse can lead to significant neurological complications, which are often under-recognized in clinical practice. Recent data on such cases in Germany are rare. We here report the spectrum of neurological complications associated with the recreational use of N₂O, as encountered in German neurology centers., Methods: We retrospectively analyzed of 23 cases presenting with neurological symptoms following N₂O abuse between July 2020 and August 2024 across five neurology departments in Germany. Data were collected on patient demographics, clinical manifestations, diagnostic findings, and treatment approaches., Results: Over the last four years the number of cases increased. Clinical presentations primarily included neuropathy, found in all patients, along with myelopathy. The most common symptoms were sensory loss, ataxia, and motor deficits., Conclusion: Our data suggest that N₂O abuse is on the rise in Germany. Further initiatives are warranted to raise awareness among users, healthcare and professionals., Competing Interests: Declarations. Ethics approval and consent to participate: According to the local ethics committee, University of Bonn, North-Rhine Westphalia, Germany (reference number 2024-358-BO) neither approval of the institutional review board nor patient informed consent were required due to the retrospective character of the analysis of anonymized patient records. All study protocols and procedures were conducted in accordance with the Declaration of Helsinki. Consent for publication: Not applicable. Competing interests: None of the authors declares competing interests., (© 2025. The Author(s).)

Background: Apraxia is a motor-cognitive disorder that primary sensorimotor deficits cannot solely explain. Previous research in stroke patients has focused on damage to the fronto-parietal praxis networks in the left hemisphere (LH) as the cause of apraxic deficits. In contrast, the potential role of the (left) primary motor cortex (M1) has largely been neglected. However, recent brain stimulation and lesion-mapping studies suggest an involvement of left M1 in motor cognitive processes-over and above its role in motor execution. Therefore, this study explored whether the left M1 plays a specific role in apraxia., Methods: We identified 157 right-handed patients with first-ever unilateral LH stroke in the sub-acute phase (< 90 days post-stroke), for whom apraxia assessments performed with the ipsilesional left hand and lesion maps were available. Utilizing the maximum probability map of Brodmann area 4 (representing M1) provided by the JuBrain Anatomy Toolbox in SPM, patients were subdivided into two groups depending on whether their lesions involved (n = 40) or spared (n = 117) left M1. We applied a mixed model ANCOVA with repeated measures to compare apraxic deficits between the two patient groups, considering the factors "body part" and "gesture meaning". Furthermore, we explored potential differential effects of the anterior (4a) and posterior (4p) parts of Brodmann area 4 by correlation analyses., Results: Patients with and without M1 involvement did not differ in age and time post-stroke but in lesion size. When controlling for lesion size, the total apraxia scores did not differ significantly between groups. However, the mixed model ANCOVA showed that LH stroke patients with lesions involving left M1 performed differentially worse when imitating meaningless finger gestures. This effect was primarily driven by lesions affecting Brodmann area 4p., Conclusions: Even though many current definitions of apraxia disregard a relevant role of (left) M1, the observed differential effect of M1 lesions, specifically involving subarea 4p, on the imitation of meaningless finger gestures in the current sample of LH stroke patients suggests a specific role of left M1 in imitation when high amounts of (motor) attention and sensorimotor integration are required., Competing Interests: Declarations. Ethics approval and consent to participate: The local ethics committee (University of Cologne) approved this single-center, retrospective study, which was carried out under the Declaration of Helsinki. Consent for publication: Not applicable. Competing interests: Gereon R. Fink is a section editor and Peter H. Weiss (-Blankenhorn) is a member of the editorial board of Neurological Research and Practice., (© 2025. The Author(s).)

Targeting of diseased cells is one of the most urgently needed prerequisites for a next generation of potent pharmaceuticals. Different approaches pursued fail mainly due to a lack of specific surface markers. Developing an RNA-based methodology, we can now ensure precise cell targeting combined with selective expression of effector proteins for therapy, diagnostics or cell steering. The specific combination of the molecular properties of antisense technology and mRNA therapy with functional RNA secondary structures allowed us to develop selectively expressed RNA molecules for medical applications. These seRNAs remain inactive in non-target cells and induce translation by partial degradation only in preselected cell types of interest. Cell specificity and type of functionalization are easily adaptable based on a modular system. In proof-of-concept studies we use seRNAs as platform technology for highly selective cell targeting. We effectively treat breast tumor cell clusters in mixed cell systems and shrink early U87 glioblastoma cell clusters in the brain of male mice without detectable side effects. Our data open up potential avenues for various therapeutic applications., Competing Interests: Competing interests: The underlying technology is patent pending in the following countries with B.H. and H.B. as inventors: Australia (PCT-AU2018222453), Canada (PCT-CA 3,054,096), Eurasia (PCT-EA 201991828), Israel (PCT-IL 2018149740), Indonesia (PCT-IN 201917032813), Japan, (PCT-JP 2019-565615). The patent has already been granted in the Republic of Korea (PCT-KR 10-2019-7024525), the USA (PCT-US 16487,377), Europe (PCT-EP-18710763.6), and China (PCT-CN 201880012606.3). The patent is owned by the SRTD Biotech GmbH. B.H. and H.B. hold shares in this company. The remaining authors declare no competing interests., (© 2025. The Author(s).)