Background: Paraneoplastic Neurological Syndromes (PNS) comprise a diverse group of disorders propagated by immune-mediated effects of malignant tumors on neural tissue. Methods: A single-center longitudinal study was performed including consecutive adult patients treated at a tertiary academic hospital between 2015 and 2023 and diagnosed with PNS. PNS were ascertained using the 2004 and the revised 2021 PNS-Care diagnostic criteria. Results: Thirteen patients who fulfilled the 2004 definite PNS criteria were included. PNS comprise diverse neurological syndromes, with neuromuscular junction disorders (54%) and limbic encephalitis (31%) being predominant. PNS-related antibodies were detected in 85% of cases, including anti-AChR (n = 4), anti-P/Q-VGCC (n = 3), anti-Hu (n = 3), anti-Yo (n = 1), anti-Ma (n = 1), anti-titin (n = 1), anti-IgLON5 (n = 1), and anti-GAD65 (n = 1). Thymoma (31%), small-cell lung cancer (23%), and papillary thyroid carcinoma (18%) were the most frequent tumors. Imaging abnormalities were evident in 33% of cases. Early immunotherapy within 4-weeks from symptom onset was associated with favorable outcomes. At a mean follow-up of 2 ± 1 years, two patients with anti-Hu and anti-Yo antibodies died (18%). Four and three patients fulfilled the 2021 PNS-Care diagnostic criteria for definite and probable PNS, respectively. Conclusions: This study highlights the clinical heterogeneity of PNS, emphasizing the need for early suspicion and prompt treatment initiation for optimal outcomes.

Background/Objectives: Myelin oligodendrocyte glycoprotein (MOG) is exclusively expressed in the central nervous system (CNS) and is found on the outer surface of oligodendrocytes. Antibodies to MOG are associated with CNS demyelination, whereas peripheral nervous system (PNS) demyelination is seldom reported to be related to MOG-IgG. Methods: The database of patients seen in our neurological academic center was searched for MOG-IgG seropositivity and concomitant demyelinating polyneuropathy. For the purpose of the review, in March 2024, we searched for case reports and case series in the following databases: PubMed, Scopus, Cochrane, and ScienceDirect. Inclusion criteria were MOG-IgG seropositivity and demyelinating polyneuropathy. Exclusion criteria were type of publication other than case reports and case series, unconfirmed diagnosis of demyelinating polyneuropathy, and other diseases causing demyelination in either the CNS or PNS. Critical appraisal of the selected case reports and case series was realized by JBI. Results: Four new cases were identified with MOG-IgG and confirmed demyelinating polyneuropathy. This review identified 22 cases that have been published since 2018. Clinical, imaging, neurophysiological, and immunological characteristics, as well as treatment options and outcomes are presented and compared to those of other cases with combined central and peripheral demyelination (CCPD). Conclusions: The pathogenetic mechanism is unclear; thus, different hypotheses are discussed. New case reporting and large cohort studies will help further the exploration of the underlying mechanism and guide more effective therapeutic interventions.

Introduction: Multiple Sclerosis (MS) is associated with a wide range of debilitating symptoms, and conventional therapies often fail to adequately address the disease’s multifaceted challenges. Cannabidiol (CBD) 13.0% + Delta9-tetrahydrocannabinol (THC) 9.0% (CBD13/THC9), a vaporized cannabis-based medicinal product, presents a novel therapeutic option for managing MS symptoms. Methods: This single-center longitudinal study followed 69 MS patients over a six-month period. Participants were assessed at treatment initiation and at three- and six-month intervals. Key measures included muscle spasticity, urine bladder dysfunction, and the evaluation of disability progression rate. The evaluation included the Modified Ashworth Scale (MAS), the Post Void Residual (PVR) volume, and the Expanded Disability Status Scale (EDSS). Results: Significant improvement was observed across all outcome assessments. The EDSS score was decreased over time (p = 0.009), indicating a slight reduction in disability progression rate, while MAS scores showed substantial improvement in muscle spasticity (p < 0.001). Urine bladder function improved significantly, with PVR volume showing notable improvement between baseline and the six-month assessment (p < 0.001). Correlation analyses revealed that a gradual increase in vaporized CBD13/THC9 dose was correlated with slightly lower EDSS scores, while the adverse effects were negatively associated with the frequency of cannabinoid use. Finally, patients who were smokers used CBD13/THC9 more frequently. Conclusions: The vaporized CBD13/THC9 formulation demonstrated notable efficacy in slightly improving disability progression rate via reduction in muscle spasticity and urine bladder dysfunction in MS patients. This highlights its addon therapeutic value during rehabilitation in MS patients with debilitating disability symptoms.

Background/Objectives: Neuropsychological impairment (NI) is common in newly diagnosed patients with multiple sclerosis (pwMS). This study has two main objectives; the systematic review aims to describe the relationship between NI and molecular biomarkers in newly diagnosed pwMS, and the meta-analysis aims to explore the relationship between NI, age, disability status, and disease duration in this patient group. Methods: We conducted a systematic review, with 20 studies meeting the inclusion criteria. Out of these, 12 studies were included in the meta-analysis. We analyzed three key cognitive measures—the Symbol Digit Modalities Test (SDMT), the Paced Auditory Serial Addition Test (PASAT), and the Selective Reminding Test–long-term storage (SRT-LTS)—in relation to demographic and MS-related characteristics. Results: Neurofilament light chain (NfL) levels were consistently associated with NI, especially a slower information processing speed (IPS). Other biomarkers, including chitinase 3-like 1 (CHI3L1), brain-derived neurotrophic factor (BDNF), apolipoprotein E4 allele (APOE4), and vitamin D, also showed promising correlations with NI. A meta-regression analysis of 2380 pwMS indicated a negative association between SDMT score and disability status (p = 0.01). No significant associations were found for the PASAT with age, disability status, or disease duration (p > 0.05). Conclusions: These findings highlight the role of NfL as a biomarker related to NI in newly diagnosed pwMS and the association between IPS and disability status. Further research is needed with more homogeneous samples in terms of the disease duration, along with standardized cognitive assessments and a broader range of biomarkers, to improve our understanding and management of cognitive difficulties in the early stages of MS.

Stavrogianni K, et al. J Clin Neurol. 2024 Nov;20(6):591-598. https://doi.org/10.3988/jcn.2024.0149

Introduction: Neuropathic pain (NP) in neuromyelitis optica spectrum disorder (NMOSD) represents a significant and often under-recognized complication arising from central nervous system (CNS) lesions. Unlike other demyelinating disorders, NMOSD involves a distinct immunopathogenesis primarily driven by aquaporin-4 antibodies (AQP4-IgG), leading to severe inflammatory damage. NP is typically the consequence of inflammatory damage to the spinothalamic tract or dorsal columns, resulting in both acute and chronic pain syndromes. Methods: A systematic review and meta-analysis were conducted following a comprehensive search of Medline and Scopus, identifying nine eligible studies reporting on NP in NMOSD. Results: Pooled prevalence was estimated using a random-effects metaprop meta-analysis with Freeman–Tukey transformation and REML-based heterogeneity estimation. The pooled prevalence of NP among patients with NMOSD was 56.2% (95% CI: 41.7–70.1%; I² = 95.3%, p < 0.001). Sensitivity analysis including only AQP4-IgG⁺ cohorts revealed a prevalence of 63.2% (95% CI: 23.4–94.7%; I² = 98.1%, p < 0.001). No significant difference was found between mixed and AQP4-IgG⁺-only populations (53.05% vs. 63.27%, p = 0.63). Meta-regression showed no significant associations between NP prevalence and age (β = 0.01, p = 0.33) or disability (β = 0.08, p = 0.18). Qualitative synthesis demonstrated an association between thoracic spinal cord lesions and NP, and also indicated that NP was often resistant and refractory to standard pharmacologic therapies. Conclusions: NP affects one in two NMOSD patients, and is associated with thoracic spinal cord lesions. In comparison with multiple sclerosis, NP in NMOSD is primarily structural and immunopathological in origin. Treatment strategies remain inadequate, emphasizing the need for early recognition and a disease-specific therapeutic approach.