Journal of Neurology

Background Heterozygous GAA-TTC repeat expansions in the FGF14 gene cause spinocerebellar ataxia 27B (SCA27B), a late-onset cerebellar ataxia (LOCA) increasingly recognized in populations of European ancestry. Objective To characterize the clinical and genetic features of SCA27B and compare its phenotype and progression with those of unexplained idiopathic LOCA (ILOCA) in a large multicenter cohort. Methods We conducted a nationwide multicenter study of patients with unexplained LOCA recruited from 21 Spanish hospitals. FGF14 GAA-TTC repeat expansions were analyzed using a standardized molecular protocol. Clinical, neuroimaging, and longitudinal data were compared between patients with genetically confirmed SCA27B and those with ILOCA. Longitudinal changes in the Scale for the Assessment and Rating of Ataxia (SARA) were analyzed using linear mixed-effects models. Results Among 430 patients with unexplained LOCA, 111 (25.8%) carried FGF14 expansions >250 repeats, and 16 additional patients (3.7%) had intermediate expansions of 200-249 repeats. Including 90 externally recruited genetically confirmed cases, the SCA27B cohort comprised 217 patients. Compared with 283 patients with ILOCA, SCA27B patients had a later age at onset (median 63 vs 55 years, p<0.001), more frequent episodic symptoms (45.2% vs 12.7%), and more frequent oculomotor abnormalities (82.5% vs 71.6%). Downbeat nystagmus was particularly frequent in SCA27B (67.4% vs 32.9%). Conversely, extracerebellar features, including pyramidal and sensory signs, were more common in ILOCA. Among patients receiving 4-aminopyridine (4-AP), subjective improvement was reported more frequently in SCA27B than ILOCA (72.5% vs 36.0%). Longitudinal SARA analysis showed similar rates of progression between groups (SCA27B slope 0.37 vs ILOCA 0.35 points/year; interaction p=0.56). Conclusions SCA27B was a frequent genetic cause of unexplained LOCA in this nationwide Spanish cohort and showed a distinct clinical phenotype characterized by later onset, episodic symptoms, oculomotor abnormalities, and frequent subjective response to 4-AP. Disease progression was similar to that observed in ILOCA. These findings support systematic FGF14 testing in patients with late-onset cerebellar ataxia, particularly those with characteristic clinical features.

Background: The Progressive Supranuclear Palsy Clinical Deficits Scale (PSP-CDS) is a brief rating scale of clinical severity in PSP. However, its longitudinal performance has not been evaluated. We aimed to assess the ability of the PSP-CDS to track disease progression over time and to compare progression across PSP phenotypes in a real-world Asian cohort. Methods: Patients who met the Movement Disorder Society PSP diagnostic criteria and underwent at least 2 PSP-CDS assessments were recruited from movement disorders clinics in Malaysia. Longitudinal progression was evaluated using linear mixed-effects models. Domain-specific progression and subtype-specific trajectories were also analyzed. Associations between annualized changes in PSP-CDS and Barthel Index (BI) scores were examined. Results: 104 patients (including 59 with PSP-Richardson's syndrome [PSP-RS], 28 with predominant parkinsonism [PSP-P], and 14 with progressive gait freezing [PSP-PGF]) contributed 394 PSP-CDS assessments over a median follow-up of 33.2 months (range, 8.7-73.1 months). PSP-CDS scores increased significantly over time ({beta}=0.126 points/month), corresponding to estimated increases of 1.13 points over 9 months and 2.27 points over 18 months. Subtype-specific analyses demonstrated the fastest progression in PSP-RS (0.156 points/month), followed by PSP-PGF (0.081 points/month) and PSP-P (0.077 points/month). Exploratory domain-level analyses showed that finger dexterity, communication, and dysphagia were the most rapidly worsening domains. Annualized PSP-CDS progression correlated significantly with annualized decline in BI scores (Spearman's {rho}=-0.474, P<0.001). Conclusions: The PSP-CDS is sensitive to longitudinal disease progression in PSP and captures clinically-meaningful functional decline. Its brevity and ability to distinguish differential progression across PSP phenotypes support its utility as a pragmatic outcome measure for routine clinical practice and research.

Background: Serial glial fibrillary acidic protein (GFAP) trajectories have become an important framework for contextualizing evolving secondary-injury pathophysiology after moderate-to-severe traumatic brain injury (msTBI). However, total GFAP pools release and clearance signals that may be less useful for longitudinal bedside decisions than a proteoform-resolved assay. We compared total GFAP with neoGFAP, defined here as calpain-generated GFAP proteoforms intended to index active astroglial proteolysis during the subacute phase. Methods: We analyzed 651 serial serum samples from 95 msTBI patients from a previously described single-site cohort. Total GFAP and neoGFAP were measured on the same MSD platform from 6 to 240 hours after injury. Early (6 to 72 h) and late (96 to 240 h) windows, data-derived tertiles, and serial trajectory summaries were calculated directly from serial samples. Models were benchmarked against age plus admission post-resuscitation Glasgow Coma Scale (GCS) and the admission IMPACT extended risk score using five-fold stratified cross-validation. Outcomes were unfavorable outcome (GOSE 1 to 4), less-than-good recovery (GOSE 1 to 6), Disability Rating Scale (DRS) [&ge;]15, mortality, and neuroimaging worsening at 6 months. Results: The cohort contributed 95 serial biomarker profiles, with 90 participants evaluable for 6-month GOSE and 89 for DRS. Unfavorable outcome occurred in 57/90 (63.3%), and less-than-good recovery in 79/90 (87.8%). For unfavorable outcome, IMPACT plus early neoGFAP reached AUROC 0.85 versus 0.84 for IMPACT plus early total GFAP and 0.81 for IMPACT alone. For less-than-good recovery, IMPACT plus late neoGFAP achieved AUROC 0.90 versus 0.84 for late total GFAP and 0.82 for IMPACT alone. Secondary analyses for DRS, mortality, and neuroimaging worsening showed smaller differences. Conclusions: In this retrospective analysis, neoGFAP provided clearer incremental value than total GFAP for recovery-oriented monitoring, especially when late-window reassessment of patients who remained at risk for less-than-good recovery was required. Results support prospective testing of neoGFAP as a pathophysiology-informed adjunct to serial bedside decision making, repeat-assessment thresholds, and recovery stratification.

Background: Pseudo-orthostatic tremor (psOT) is a rare form of tremor of the lower body, triggered by standing, at frequencies lower than 13 Hz. It is believed to be secondary to other neurological disorders in a large proportion of cases. Surface electromyography (sEMG) can identify its core characteristics and differentiate it from other similar disorders such as primary orthostatic tremor (POT) and orthostatic myoclonus (OM). Objectives: Our study aims to illustrate the clinical and neurophysiological features as well as the outcomes and final diagnoses of patients with psOT in a retrospective two-centre cohort. Methods: We retrospectively examined the available clinical and neurophysiological records of 35 consecutive patients with a diagnosis of psOT in the 2022-2026 period. Data on demographics, clinical characteristics, sEMG findings, pharmacological treatments, ancillary investigations and patient reported outcomes were collected. Results: 35 patients with psOT were identified, of which 6 (17%) displayed features consistent with a functional neurological disorder (FND). Among the 29 patients with organic psOT, 21 (72.4%) fulfilled the diagnostic criteria for essential tremor (ET), while an identifiable neurological cause was established in four (13.8%). sEMG findings differed between functional and organic psOT, with the latter often displaying features consistent with weight-bearing hyperkinesias. Conclusions: Our retrospective study suggests that psOT is most often associated with ET, while an identifiable neurological cause was found in a relatively small proportion of patients. We also describe functional psOT as a previously unrecognized clinical presentation of FND.

Introduction The Brief Ataxia Rating Scale (BARS) and Scale for the Assessment and Rating of Ataxia (SARA) are used to quantify cerebellar ataxia severity. We investigated how often clinician ratings match patient reports of functional impairment, which scale items patients consider important, and whether incremental changes in item scores are meaningful to patients. Methods 30 patients with cerebellar ataxia completed BARS, SARA, FARS Functional Staging, and an Importance of Activities of Daily Living questionnaire. We studied BARS and SARA item scores for over- or underestimation in relation to patient perception of impairment. We explored patient rankings of item importance in relation to daily function, and their perception of the likely importance of 0.5- and 1-point changes in BARS gait and speech. Results Patients identified gait as most important on BARS and SARA, followed by oculomotor (BARS) and stance (SARA). Heel-to-shin was least important, with highest overestimation on both scales. Total overestimated points were similar between BARS (2.65 +/- 2.80) and SARA (2.78 +/- 2.78). 0.5-point changes in BARS gait and speech scores were rated very or extremely important by 60% and 46.6%, respectively, increasing to 83.3% and 70% for a 1-point change. Conclusion Gait is most meaningful to patients with cerebellar ataxia. BARS oculomotor and SARA stance rank second. BARS and SARA appendicular measures have limited patient-perceived clinical meaningfulness. 0.5-point increments in BARS gait and speech provide greater granularity of assessment and are considered meaningful by a substantial proportion of patients, supporting their relevance in practice and in clinical trials.

Objective: Patients with persistent postural-perceptual dizziness (PPPD) perceive unsteadiness associated with abnormal ego- or visual motion perception. Maladaptive multisensory integration and visual dependency have been proposed implicating abnormal functional connectivity (FC). Based on the crucial impact of the cerebellum for prediction errors of sensory perception, we specifically investigated group-related differences in FC between visual cortex, multisensory vestibular cortical areas and the cerebellum. Methods: Resting-state activity (seed-based functional connectivity using a priori regions of interest and fractional amplitude of low-frequency fluctuations, fALFF) was compared between a large cohort of 53 PPPD patients and 54 age- and sex-matched HC and related to various disease parameters and baseline postural sway speed. Results: FC between the patients' posterior insula and the visual (lingual) cortex, as well as the supramarginal gyrus was lower. In contrast, it was markedly larger between the patients' (i) visual motion-related area MT/V5 and cerebellar Crus I, (ii) multisensory operculum and caudal vermis, (iii) OP3 and Crus II, and (iv) inferior parietal lobe and vermis. fALFF was larger in the patients' right hippocampus. Interpretation: The abnormally low cortical visual-vestibular FC may provide a neural substrate for the patients' maladaptive multisensory integration with aberrant inter-sensory reweighting. The larger cerebro-cerebellar FC with cerebellar areas involved in sensory and postural prediction errors control (required for updating internal models of motion) might account for the abnormally high sensory precision weighting leading to the patients' altered egomotion perception. Longitudinal studies are required to investigate whether the larger cerebrocerebellar connectivity is compensatory or dysfunctional in nature.

Background: Localized or segmental overgrowth is a rare condition that may co-occur with vascular malformations. These diseases generally are caused by somatic mutations in the PI3K/AKT/mTOR pathway. Most lesions are progressive and may cause symptoms including pain, functional impairment, and disfigurement. Treatment options are limited, especially for the overgrowth component. Objective: To evaluate the efficacy and safety of the mTOR inhibitor sirolimus in patients with overgrowth with or without a vascular malformation over a 6-months treatment period. Methods: We conducted a single-arm, open-label, phase II study including 18 patients (12 pediatric, six adult) with overgrowth, all of whom initiated oral sirolimus. 16/18 (88.9%) participants received oral sirolimus for 6 months, with dosing adjusted to achieve target blood trough levels of 3-8 ng/mL. Primary outcome was radiological response at six months assessed by the Response Evaluation Criteria in Solid Tumors (RECIST) 1.1. Secondary outcome parameters were evaluated at three, six and nine months and included size and visual appearance of the overgrowth, quality of life (QoL), pain intensity, performance status, and safety. Results: No patient achieved complete or partial radiological response. 17 of 18 patients (94.4%) maintained stable disease at month six; one was not evaluable. QoL measured with WHOQOL-BREF improved modestly in patients aged >= 18 years (n=5, mean difference to baseline +9.3 (95%-CI: -0.9 to 19.5) in physical and +9.2 (95%-CI: 0.7 to 17.7) in psychological domains at month 6). In pediatric participants, no relevant improvement in KINDL total scores was observed over the study period. No significant changes occurred in pain scores. Performance status measured by the Lansky/Karnofsky scales showed minor improvement (mean +3.5 points (95%-CI: 1.0 to 6.1)). All patients experienced at least one adverse event, but no serious adverse events or CTCAE v5.0 grade [&ge;]3 toxicities occurred. Sirolimus was well tolerated. Six patients decided to resume sirolimus after study completion. Conclusions: Sirolimus induced minor lesion shrinkage in a subset of patients, although this did not meet the predefined radiological RECIST endpoint. However, sirolimus can lead to functional improvement in some adults, which may indicate that the primary radiological outcome did not capture patient-perceived benefit.

Background: Cervical spinal cord (CSC) compression and myelopathy are frequent, severe complications in mucopolysaccharidosis (MPS) types I and VI. Early detection is critical to prevent irreversible neurological deficits and preserve quality of life. This prospective study aimed to identify quantitative neuroimaging biomarkers of structural CSC damage and myelopathy in MPS I and VI. Methods: Structural and diffusion magnetic resonance imaging (MRI) of the CSC was analyzed in 17 MPS I patients, 3 MPS VI patients (19{+/-}7 years), and 19 case-matched healthy controls (20{+/-}7 years). CSC macrostructure (cross-sectional area, diameters) and microstructure (fractional anisotropy [FA], radial [RD], mean, axial diffusivities) were evaluated within and beyond the maximal compression areas. Results: MPS patients demonstrated reduced CSC cross-sectional area and anterior-posterior diameter at upper cervical levels, alongside widespread microstructural alterations (lower FA, higher RD) throughout the CSC versus controls (pFDR<0.05). Restricted foramen magnum space was associated with microstructural damage at lower cervical levels without overt macrostructural compression. Morphological and microstructural metrics were sensitive to CSC compression and myelopathy severity (pFDR<0.05). Lower CSC integrity correlated with more advanced growth retardation (p<0.001). Among patients receiving hematopoietic stem cell transplantation, earlier treatment correlated with preserved upper CSC morphology (p<0.05). Distinct neuroimaging phenotypes were observed across MPS genotypes (pFDR<0.05). Conclusions: CSC MRI provides candidate neuroimaging biomarkers for early detection and characterization of myelopathy in MPS I and VI. Structural damage extends beyond primary maximal compression areas, highlighting these markers for clinical monitoring and future therapeutic trials.

Introduction Post stroke dysphagia is common, associated with poor functional outcome and lacks treatment strategies beyond behaviour therapies delivered by speech & language therapists. Here, we present the statistical analysis plan for the ongoing pharyngeal electrical stimulation for acute stroke dysphagia trial (PhEAST). PES is a candidate treatment for dysphagia present in non-ventilated stroke patients. Methods PhEAST is an investigator-initiated international prospective randomised open-label blinded-endpoint phase-4 superiority trial involving 650 participants with tube-dependent post-stroke dysphagia. Consenting patients are randomised to PES versus no PES given on top of standard care with PES given daily for 6 days. The primary outcome is the dysphagia severity rating scale (DSRS), a measure of swallowing impairment, made at days 14 and 90 and analysed using repeated measures regression. Conclusion We present the statistical analysis plan for the main analyses based on data up to day 90 along with planned secondary analyses including presentation of baseline data, health economics, cognition and extended follow-up to 12 months.

Background: Therapy development in ultra-rare, progressive and fatal diseases like vanishing white matter (VWM) is hampered by very low patient numbers and ethical constraints regarding placebo-controlled studies. Under such conditions, standard randomized controlled trials may not be feasible. The use of historical control information could be part of a solution, but would require extra considerations regarding selection of patients and choice of endpoints. We used the VWM registry as a case study to outline key methodological considerations for informing trial design in ultra-rare disease. Methods: The study included 462 patients, available in the VWM registry. Prospective clinical data were collected since 2004 using VWM-specific questionnaire and Health Utility Index (HUI) assessments, while retrospective data from clinical charts were available from 1988 on. We evaluated methodological aspects relevant to trial design, including patient selection, drift in the disease course over time, endpoint selection, and clinically relevant stratification into subgroups. Results: Regarding patient selection, patients with comorbidities impacting disease course, and pre-symptomatic individuals without clinical onset were considered not suitable as historical controls. After excluding patients before 1991, we found no evidence of drift in the disease course from 1991 onwards. Regarding choice of endpoints, episodes of rapid decline were relatively infrequent and occurred mostly at disease onset, limiting their usefulness as trial endpoint. Multi-state modelling and clinical evaluation showed ambulation as preferable endpoint over survival. For longitudinal HUI multiscores, baseline imputation allowed modelling of early disease. The scores showed a distinct ordering, reflecting the association between multi-domain function and disease progression. Regarding stratification, the combination of data-driven analyses and clinical expertise informed revised age of onset groups. Females showed later onset and milder disease; adjustment for age of onset eliminated the effect of sex. Conclusion: This case study provides key considerations for evaluating registry data as historical control and demonstrates how these considerations can inform clinical trial design in ultra-rare diseases.

Introduction/Aims To evaluate the usefulness of the Goal Attainment Scale (GAS) light for assessing response to risdiplam in patients with SMA aged [&ge;]15 years. Methods In this population-based, longitudinal, ambispective study, patients were evaluated before and at 12 and 24 months after risdiplam initiation using motor scales (SMA Functional Composite Score Revised [SMA-FCR]), pinch strength (MyoPinch), functional scales (EK2, ALSFRS-R), patient and clinician global impression of change (PGIC and CGIC), and GAS light. Longitudinal changes were assessed using linear mixed-effects models. The minimal detectable change (MDC) and minimal clinically important change (MCIC) of GAS light were calculated. Results Forty-four patients (median age 32 years; 56.8% female) were included: 31.8% non-sitters, 56.8% sitters, and 11.4% walkers. GAS light priorities differed across functional subgroups, with patients prioritising moderately affected domains. After 24 months of risdiplam treatment, motor outcomes showed non-significant improvements in walkers, whereas functional scales improved significantly only in non-sitters. In contrast, GAS light detected significant, increasing improvements across all functional subgroups. The MCIC and MDC for GAS light were 6.5 and 10.65 points, respectively. According to the CGIC, 58% of patients improved slightly, 29% remained stable, and 13% worsened slightly at 24 months. Using the MCIC threshold, 64.5% achieved clinically meaningful goal improvement. Discussion GAS light is a feasible, sensitive, patient-centred tool that may complement standardised outcome measures when evaluating treatment response in adults with SMA. These findings further support risdiplam as a valuable therapeutic option in this population.

Background: Storage symptoms after stroke-isolated urgency, urgency with frequency, and isolated frequency are common but traditionally attributed to a single overactive bladder mechanism via suprapontine disinhibition. However, clinical heterogeneity in symptom presentation suggests distinct underlying mechanisms. We aimed to characterize the neural substrates of three storage symptom subtypes after stroke using comprehensive lesion-symptom mapping. Methods: We prospectively evaluated 1,498 consecutive subacute stroke patients admitted for inpatient rehabilitation (1,105 men, 73.8%; median age 61 years). Storage symptoms were classified into three subtypes: isolated urgency (n=109), urgency with frequency (n=32), and isolated frequency (n=19). Multivariable logistic regression models with Bonferroni correction identified independent predictors across demographic, clinical, white matter hyperintensity (WMH), brain atrophy, and lesion location variables. Results: The three subtypes demonstrated largely distinct sets of independent predictors. The left genu of the corpus callosum (aOR=20.06, 95% CI 7.78-51.74, P<0.001) and the inferior frontal gyrus (aOR=3.48, 95% CI 1.81-6.67, P<0.001) were independently associated with isolated urgency and survived Bonferroni correction, together with a right IFG-insula synergistic effect (OR=21.46, 95% CI 10.49-43.88, P<0.001). Urgency with frequency was associated with a broad fronto-cingulate network-the IFG (aOR=11.45, 95% CI 3.10-42.33, P<0.001, surviving Bonferroni correction) and the ACC (aOR=11.53, 95% CI 2.40-55.49, P=0.002) with diffuse right-hemisphere dominance, older age and brain atrophy. Isolated frequency was associated with anterior corona radiata involvement (aOR=5.46, 95% CI 1.92-15.54, P=0.002) and male sex (aOR=10.62, 95% CI 1.36-82.98, P=0.024), though none reached the strict Bonferroni threshold. Conclusions: These findings identify three mechanistically distinct post-stroke storage symptom subtypes with separable neural substrates, lateralization profiles, and clinical determinants. The triple dissociation across subtypes supports a discrete pathway model over the traditional unitary OAB framework, providing a neuroanatomically grounded basis for subtype-stratified treatment Keywords: storage symptoms; subacute stroke; hemispheric lateralization; structural synergy; lesion-syndrome mapping

Background: Idiopathic normal pressure hydrocephalus (iNPH) is a potentially treatable neurological disorder whose molecular basis remains incompletely understood. Metabolomic studies in iNPH are scarce and have focused largely on comparisons with other neurological disorders or on cerebrospinal fluid (CSF) alone. Consequently, the broader metabolic phenotype of iNPH and the extent to which CSF alterations are reflected in peripheral blood remain unclear. We therefore compared paired CSF and plasma metabolomic profiles from patients with iNPH and controls. Methods: Paired CSF and plasma samples from 10 patients with iNPH and 10 controls were analyzed via hydrophilic interaction liquid chromatography-mass spectrometry. After quality control and deduplication, 134 CSF and 149 plasma metabolites were quantified. Protein-normalized abundances were log2-transformed and analyzed via age-adjusted ordinary least-squares regression as the primary model, with group-only regression and Mann-Whitney U tests used for sensitivity analyses. Significance was defined as Benjamini-Hochberg q < 0.05 and |log2-fold change| larger or equal to log2(1.5). Results: Age-adjusted analysis revealed 56 altered CSF metabolites in iNPH patients, 34 of which were increased and 22 of which were decreased; 47 were also significantly altered according to the Mann-Whitney U test. The CSF phenotype encompassed energy and carnitine/acylcarnitine metabolism, redox and one-carbon/transsulfuration-associated metabolism, tryptophan-kynurenine metabolism, amino acid and nucleotide turnover, and neuronal- or membrane-associated metabolites. Prominent changes included increased succinate, 3-hydroxybutyrate, oxidized glutathione, cystathionine, kynurenine and kynurenic acid, together with decreased carnitine, short-chain acylcarnitines, methionine and ergothioneine. In plasma, 27 metabolites met the age-adjusted significance criteria, but only allantoin, N-formylmethionine, 3-hydroxybutyrate, N-acetylmethionine and kynurenic acid were also significant according to the Mann-Whitney U test. Global CSF-plasma effect-size concordance was moderate. The most consistent cross-compartment features were 3-hydroxybutyrate, N-formylmethionine and N-acetylmethionine. Conclusions: iNPH was associated with a broad and comparatively consistent CSF-centered metabolic phenotype, whereas plasma showed a smaller, partial and model-sensitive reflection of these alterations. These findings support altered energy substrate handling, redox and sulfur-associated metabolism, tryptophan-kynurenine metabolism and neuronal or membrane-associated metabolite handling as components of iNPH biology. These exploratory findings require validation in larger, longitudinal cohorts.

Persistent neurological symptoms are among the most disabling manifestations of post-COVID-19 syndrome (PCS), yet the contribution of ongoing CNS immune activation remains uncertain. CSF studies including clinically relevant COVID-19 recovered control cohorts are scarce. In this prospective single-center study, we enrolled 50 patients fulfilling the WHO criteria for PCS (COVIDpost, mean age +/- standard deviation [SD] 43.41 +/- 11.99 years, 30 % male, 70 % female) and 50 individuals who had fully recovered from COVID-19 (COVIDreco, mean age +/- SD 39.38 +/- 13.45, 42 % male, 58 % female). Both cohorts were comparable regarding age (p = 0.07), sex (p = 0.30), and education (p = 0.84). All participants underwent paired CSF and serum analyses together with comprehensive neuropsychological assessment. Routine CSF parameters, blood-CSF barrier integrity, oligoclonal bands (OCB), SARS-CoV-2 RNA in CSF and blood, pathogen-specific antibody indices, and neuronal autoantibodies were investigated. Despite marked differences in cognitive performance (p < 0.001) and fatigue severity (p < 0.001), patients with PCS showed no evidence of disease-specific CSF abnormalities compared to recovered controls. Routine CSF parameters, blood-CSF barrier dysfunction, CSF-restricted OCB, SARS-CoV-2 RNA in CSF and blood, intrathecal SARS-CoV-2 antibody synthesis, polyspecific antiviral immune responses, and neuronal autoantibodies were comparable between groups. SARS-CoV-2-specific IgG concentrations in CSF correlated positively with serum concentrations (COVIDpost: r [95%CI] = 0.78 [0.62 - 0.87]; COVIDreco: r [95%CI] = 0.86 [0.75 - 0.92]; both p < 0.001) and albumin quotient (COVIDpost: r [95%CI] = 0.52 [0.26 - 0.71], p < 0.001; COVIDreco: r [95%CI] = 0.37 [0.10 - 0.60]; p = 0.01), consistent with passive transfer across the blood-CSF barrier rather than compartmentalized intrathecal immune activation. Furthermore, SARS-CoV-2-specific antibody measures were not associated with cognitive performance (p > 0.72) or fatigue severity (p > 0.88). This study provides no evidence that persistent neurological symptoms after COVID-19 are accompanied by ongoing adaptive CNS immune activation, disease-specific neuronal autoimmunity, or intrathecal SARS-CoV-2-specific humoral immune responses. The inclusion of a carefully phenotyped COVID-19 recovered comparison cohort strengthens the conclusion that routine CSF abnormalities largely do not seem to reflect mechanisms specific to PCS. These findings argue against routine CSF diagnostics as a source of disease-specific biomarkers in unselected PCS patients and support future studies focusing on alternative mechanisms underlying persistent neurological symptoms.

Background: Hereditary spastic paraplegia (HSP) comprises a heterogeneous group of neurodegenerative disorders characterized by progressive lower-extremity weakness and spasticity, with or without additional neurological symptoms. Objectives: To characterize the molecular genetic spectrum, inheritance patterns, molecular finding rate, and clinical characteristics of HSP within a multicenter Canadian cohort. Methods: We investigated 671 patients from 423 families who met clinical criteria for HSP identified through the Canadian HSP (CanHSP) registry from 7 medical centers across Canada. Patients were evaluated using known HSP and HSP mimic gene panels, whereas unsolved and more recent patients underwent whole-exome sequencing (WES). 435 individuals underwent gene-panel testing and 485 underwent WES. Copy-number variants (CNVs) were assessed using ExomeDepth, and candidate CNVs using multiplex ligation-dependent probe amplification (MLPA). Results: Molecular findings were identified in 426 of 671 individuals (63.5%): 351 (52.3%) had HSP-associated findings, 70 (10.4%) HSP-mimicking disorders, and five (0.7%) other molecular findings; 245 (36.5%) remained unresolved. Candidate variants were found in 80 relevant genes, 36 of which were HSP-associated genes. The most frequently implicated genes were SPAST (22.5%), SPG7 (5.7%), ATL1 (5.2%), SPG11 (3.6%), and SPG8 (3.3%). Phenotypically, SPAST, ATL1, and SPG8 w[zg1.1]ere predominantly associated with pure HSP, whereas SPG7 and SPG11 more often showed complicated phenotypes, with prominent cerebellar involvement in SPG7 and cognitive and developmental features in SPG11. Conclusion: Patients in CanHSP present with genetic and phenotypic heterogeneity. Reanalysis and complementary approaches, including whole-genome, RNA, and long-read sequencing, may increase diagnostic yield.

GM1 gangliosidosis is an inherited, progressively neurodegenerative lysosomal storage disorder with no approved therapy. We report 5-year safety and 3-year clinical, biochemical, and neuroimaging efficacy outcomes following expanded-access intravenous AAV9-GLB1 gene therapy in GT01, a 6-10-year-old female with juvenile-onset GM1 gangliosidosis. During participation in a natural history study before gene transfer, GT01 developed seizures, dysarthria, loss of ambulation, and progressive neurodegeneration. She received a single intravenous administration of AAV9-GLB1 at 1.5x1013 vector genomes per kilogram of body weight. Early improvements included the resolution of dysphagia, increased interactions with others, assisted ambulation, and gains in specific domains of adaptive functioning. She was seizure-free without anti-epileptic drugs 18 months post dosing with sustained seizure freedom at the study completion. Cerebrospinal fluid concentrations of GM1 ganglioside and H3N2b (a pentasaccharide biomarker indicative of biochemical improvement in this disorder) concentrations decreased by 50% and {beta}-galactosidase reached normal activity. Brain, thalamic, and net fiber tract volume assessed by differential tractography increased and ventriculomegaly improved three years post-dosing. These results indicate that meaningful benefit can be achieved even in advanced neurologic disease.

Background: Glial fibrillary acidic protein (GFAP) is a promising blood biomarker that can distinguish intracerebral hemorrhage (ICH) from acute ischemic stroke (AIS). We aimed to summarize the existing evidence regarding: 1) the diagnostic accuracy of GFAP to differentiate ICH from AIS, and from undifferentiated suspected stroke, and 2) characterize GFAP's diagnostic accuracy across time strata from stroke onset. As a secondary objective, associations between GFAP and clinical and radiological outcomes were narratively summarized. Methods: Five databases [(MEDLINE/EMBASE/EBM Reviews/CINAHL Complete/Google Scholar] were searched (03/2026) for studies reporting blood GFAP levels in acute stroke. GFAP levels were analyzed according to time from onset to sampling. Risk of bias was assessed using QUADAS-2 for studies reporting diagnostic accuracy data. Forest plots, pooled sensitivities and specificities were calculated. Results: Two reviewers independently screened 6,336 studies; 64 were included for systematic review and 18 for meta-analysis. Risk of bias was low overall among diagnostic studies. For differentiating ICH from AIS, pooled AUC was 0.86 (95% CI: 0.76-0.92), pooled sensitivity 74.4% (95% CI:63.2-84.2%) and pooled specificity 87.2% (95% CI:77.0-94.7%). For ICH versus undifferentiated suspected stroke, pooled AUC was 0.88 (95% CI: 0.79-0.95), pooled sensitivity 75.4% (95% CI: 63.6-83.3%) and pooled specificity 90.5% (95% CI:88.0-96.2%). Diagnostic precision improved in earlier time strata: <6h: AUC 0.91, sensitivity 75.0%, specificity 92.7%; <2h: AUC 0.96, sensitivity 76.7%, specificity 96.4%. GFAP correlated with ICH volume in 11/12 studies, although smaller hematomas (<10 mL) were frequently associated with GFAP values below limits of detection. Few studies (n=3) suggest higher GFAP levels correlate with greater ischemic injury in AIS. Conclusions: As a blood biomarker in acute stroke, GFAP has strong rule-in value (i.e. high specificity) for ICH, which is preserved in earlier time windows. Nevertheless, sensitivity remains limited, restricting its use as a rule-out test, particularly for smaller ICH volumes. Knowledge gaps remain regarding GFAP's potential in assessing ischemic injury extent in AIS.

BACKGROUND: Existing models for discharge to long-term institutional care after stroke are developed within single health systems and pool to an area under the curve near 0.80, but none is accompanied by an estimate of how much of the outcome is a property of the health system rather than the patient. METHODS: Secondary analysis of the International Stroke Trial, a randomised trial in 19,435 patients with suspected acute ischaemic stroke recruited in 1991-1996 across 36 countries. Among 14,885 survivors to six months with residence recorded, we developed and internally validated a logistic prognostic model for residential or nursing-home residence using 17 admission-day terms, and compared it against a pre-specified benchmark of age and stroke syndrome alone. Between-country variation was estimated by a method-of-moments decomposition with a cluster bootstrap. RESULTS: Institutional residence was recorded for 1,984 of 14,885 survivors (13.3%); the model was fitted on 14,121 patients containing 1,935 events. In 10-fold cross-validation with the whole procedure refitted per fold, the out-of-fold c-statistic was 0.789, calibration slope 0.987, calibration-in-the-large 0.1371 predicted against 0.1370 observed, and Brier score 0.1013. A benchmark of age and stroke syndrome alone reached an optimism-corrected 0.774 against 0.790 for the full model, a corrected difference of 0.0160. Between-country variation gave an intraclass correlation of 0.0409 (0.0191 to 0.0673), and in leave-one-country-out validation the c-statistic ranged from 0.635 to 0.823 across the 14 countries with enough events to estimate it. CONCLUSIONS: Institutional residence after stroke can be stratified at admission with discrimination comparable to existing models and calibration that holds in unseen patients, but almost all of the signal is carried by age and stroke syndrome. Performance varies substantially between countries, pointing to placement systems as the limit on what a pooled model can do.

Background: The condition of a patient with acute stroke often changes within hours of ICU admission. Prognostic work here targets fixed endpoints predicted from admission data, and trajectory phenotyping assigns one label per patient. We used longitudinal ICU data to identify interpretable dynamic clinical states, characterize transitions between them, and relate the current state to later events. Methods: Retrospective cohort study of 6368 adults with acute stroke in MIMIC IV v3.1. The first 72 h were divided into twelve 6-hour windows, and a hidden Markov model was fitted to 21 neurological, physiological and organ support variables. State number was chosen against criteria fixed before fitting: statistical fit, restart stability, state occupancy and clinical interpretability. Generalized estimating equations related the current state to new mechanical ventilation and vasopressor use within 12 h, and to ICU death within 72 h. Eleven sensitivity analyses assessed the robustness of the state solution. Results: Four states were selected: neurologically preserved-low support, neurological impairment low support, impairment renal dysfunction and impairment-respiratory support (63.3%, 7.8%, 11.8% and 17.1% of windows). Within 72 h, 40.3% of patients changed state at least once, and transitions ran in both directions rather than along a single severity gradient. States were identified without outcome data, yet ICU mortality by last state ranged from 2.9% to 43.9%. Adjusted for age, sex, subtype and Charlson index, the current state remained associated with organ-support escalation and death. State prevalence differed by at most 1.1 percentage points between training and test sets, and 10 of 11 sensitivity analyses gave a stable four-state solution (ARI 0.754 0.955). Conclusions: The early ICU course of acute stroke can be represented as movement among a small number of clinically interpretable states. The representation was reproducible in a held out set and across admission eras, but requires validation in an independent database before any clinical use.

Background Patients with acute ischemic stroke (AIS) attributable to symptomatic intracranial atherosclerotic disease (sICAD) remain at substantial risk of early neurological deterioration (END) despite standard medical treatment. Aim To determine whether early addition of a proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor to statin therapy reduces END in patients with AIS attributable to sICAD within 48 hours of symptom onset. Design The study of Combined Therapy with PCSK9 Inhibitor and Statin in Acute Ischemic Stroke (CAPTAIN) is a multicenter, prospective, randomized, open-label, blinded-endpoint trial conducted in China, with a planned sample size of 416 patients. Eligible patients will be randomized in a 1:1 ratio to receive either early evolocumab plus standard-dose statin or standard-dose statin therapy. Outcomes The primary efficacy outcome is the occurrence of END within 3 days after randomization, defined as an increase in the National Institutes of Health Stroke Scale score of at least 2 points from baseline. Secondary efficacy outcomes include neurological improvement, changes in National Institutes of Health Stroke Scale (NIHSS) score, shift in the 90-day modified Rankin Scale score distribution, recurrent stroke, and changes in lipid parameters. The primary safety outcome is the incidence of moderate-to-severe systemic bleeding within 3 days after randomization, as defined by the GUSTO criteria. Conclusions This study is expected to provide evidence on the efficacy and safety of the early addition of a PCSK9 inhibitor to statin therapy in patients with AIS attributable to sICAD. Trial registration number NCT06696820