cover image European Journal of Neurology

European Journal of Neurology

2025 - Volume 32
Issue 12 | December 2025

ISSUE INFORMATION

Issue Information

ORIGINAL ARTICLE

Background

Epidemiological studies on amyotrophic lateral sclerosis (ALS) in Greece are scarce and outdated.

Methods

We performed an observational cohort study in 11 specialized centres across Greece. Adult individuals with ALS diagnosed based on the Gold Coast criteria were recruited. Data were collected on socio‐demographics, somatometrics, comorbidities, early life exposures, disease‐related parameters, riluzole intake, motor and non‐motor symptoms, as well as functional progression. Follow‐up evaluations were scheduled on approximately 6–9–12–18–24 months. Our aim was to identify shortcomings in the monitoring of patients with ALS in specialized centers, delineate the course of the disease, and capture factors related to the earlier occurrence of ALS and potential diagnostic delays.

Results

A total of 229 ALS patients were included in the present registry. The average age of diagnosis was 63.7 years, with an average 12.8‐month interval between symptom onset and diagnosis. The presence of bulbar symptoms at onset was associated with shorter diagnostic delays. Systematic physical exercise was strongly linked to the earlier onset of symptoms. Disease progression was slower during the prediagnostic stage, more precipitous over the first year following diagnosis, and milder thereafter (~1‐point monthly decline in ALSFRS‐R on average, post‐diagnosis). The majority of associated motor and non‐motor symptoms accumulated over time. The overwhelming majority of patients were prescribed the liquid form of riluzole, which exhibited an excellent tolerability profile. Greek islands are probably the most underprivileged in terms of specialized monitoring of ALS cases.

Conclusions

The present observational cohort study mapped key aspects and shortcomings of ALS management in Greece.

ORIGINAL ARTICLE

Background

We systematically evaluated the different components of the motor unit using an integrated set of noninvasive electrophysiological techniques across a broad spectrum of disease severity in symptomatic adolescents and adults with spinal muscular atrophy types 1–4.

Methods

We performed detailed electrophysiological mapping of the median nerve, including the compound muscle action potential scan, and repetitive nerve stimulation, in 104 genetically confirmed patients with SMA (aged ≥ 12 years, types 1c–4) before the start of DMT. We compared data to a reference group of 65 healthy controls.

Results

Motor unit patterns were significantly altered in patients with SMA, showing severe motor unit loss and enlarged motor units. Distinct patterns reflected disease severity, independent of age or disease duration. Patterns were characterized by varying proportions of enlarged motor units relative to motor unit number, with significantly reduced motor unit number and high contributions of enlarged units in advanced disease stages. Neuromuscular junction (NMJ) dysfunction (≥ 10% decrement) was present in 13%–38% of patients, irrespective of SMA severity. In line with these findings, clinical motor function scores correlated with greater motor unit loss and higher contributions of enlarged motor units.

Conclusions

We identified altered motor unit patterns and NMJ function in patients with SMA, with distinct patterns across SMA severity independent of age or disease duration. These measures may serve as complementary biomarkers for disease severity in patients with SMA.

Trial Registration

Dutch registry for clinical studies and trials (): NL72562.041.20 (March 26, 2020)

ORIGINAL ARTICLE

Background

Predicting prognosis in people with multiple sclerosis (pwMS) at early disease stages still remains an unmet need. Machine learning (ML) strategies demonstrated good reliability when applied for prediction in medicine. This study aimed at developing a predictive algorithm comparing different ML approaches, by using routine demographic, clinical and radiological data from a large multicentric cohort of newly diagnosed pwMS.

Methods

Demographic, clinical, radiological and biochemical data were retrospectively collected at three Italian MS centers at baseline and four timepoints thereafter (6, 12, 24, and 36 months). Data from the first evaluation and subsequent 2‐year follow‐up were analyzed, comparing different ML models (Random Forest, Extra Trees, XGBoost, Logistic Regression and Support Vector Classifier) to predict progression independent of relapse activity (PIRA) at year 3. To understand how features impacted the selected model's output, a ML explainability analysis was performed on the whole cohort and on specific subsets of patients, those aged under 45 and those NEDA‐3 at the 2‐year follow‐up.

Results

Data from 719 pwMS (age 34.6 ± 11.2 years); female sex 501 (70%) were analyzed. Ninety‐two pwMS (13%) developed PIRA at year 3. Random Forest achieved the highest score, with a test set area under the ROC curve (AUC) of 0.75 ± 0.06. Features with the highest predictive impact were Expanded Disability Status Scale at 24 months, age at symptom onset and disease duration at baseline.

Conclusion

Our results showed the feasibility of applying ML techniques to predict short‐term PIRA in newly diagnosed pwMS by using routine clinical practice data, paving the way for tailored and personalized approaches.

LETTER TO THE EDITOR

Response to Letter to the Editor: Headache After Sealing of Cerebrospinal Fluid Leaks in Patients With Spontaneous Intracranial Hypotension

LETTER TO THE EDITOR

Letter to the Editor: Headache After Sealing of Cerebrospinal Fluid Leaks in Patients With Spontaneous Intracranial Hypotension

ORIGINAL ARTICLE

Background

Persistent headache after SARS‐CoV‐2 infections and vaccination has been reported. However, limited data exist on the risk of new‐onset headache after these exposures compared to unexposed periods in the general population.

Methods

We used data from three population‐based cohorts ( = 85,774, age 19–81 years). SARS‐CoV‐2 infections and vaccinations were obtained from national registries and questionnaires. Before and after Omicron emergence, participants stated whether they had been suffering from headache during the past year, reported headache characteristics, and time of onset. Time‐dependent exposures were used to investigate the impact of SARS‐CoV‐2 infection and vaccination on the risk of new‐onset headache. Headache subtypes were secondary outcomes.

Results

SARS‐CoV‐2 infection and first and second vaccine doses were associated with increased risk of new‐onset headache. The three cohorts, representing different age groups, were analyzed separately. For pre‐Omicron infections, the hazard ratio (HR) was 6.7 (95% confidence interval (CI) 4.8–9.2) and 6.5 (95% CI 3.8–11.1) among middle‐aged women and men, respectively. For Omicron infection, HRs were 4.7 (95% CI 4.1–5.4) and 4.5 (95% CI 3.7–5.4), respectively. The risk increased with infection severity. Corresponding HRs for first and second vaccine doses, administered during low transmission, were 1.6 and 1.7, respectively, in women, and 1.5 for both doses in men. The third dose, given before the Omicron surge, was associated with 20%–40% protection against new‐onset headache.

Conclusions

SARS‐CoV‐2 infection was strongly associated with new‐onset headache. Primary vaccination was associated with a small increased risk of headache during a low‐transmission period, whereas booster vaccination offered protection during high‐transmission.

ORIGINAL ARTICLE

Background

We investigated whether diffusion tensor imaging (DTI) and atlas‐based volumetry (ABV) could track specific patterns of brain white matter (WM) microstructure and gray matter (GM) volumes in behavioral variant frontotemporal dementia (bvFTD) and amyotrophic lateral sclerosis with frontotemporal dementia (ALS‐FTD).

Methods

MRI datasets from 65 bvFTD (including 19 with longitudinal MRI), 18ALS‐FTD, and 39 controls were analyzed. White matter fractional anisotropy (FA) differences were assessed using unbiased Whole Brain‐based Spatial Statistics (WBSS) and a hypothesis‐driven complementary approach consisting of Tract‐Wise FA Statistics (TFAS) in Tracts of Interest (TOIs) and ABV in Structures of Interest (SOIs). FA maps were correlated with disease severity (FTLD‐CDR sum of boxes). A random forest algorithm classified participants employing TOI and SOI data.

Results

At baseline, both bvFTD and ALS‐FTD exhibited WM changes in several tracts including the uncinate fasciculi, tracts originating in the corpus callosum, and the inferior and superior longitudinal fasciculi. Atrophy was most pronounced in the frontal lobes and caudate nuclei. Longitudinally, bvFTD demonstrated an antero‐posterior spread of WM degeneration, particularly along the corpus callosum and inferior longitudinal fasciculus, with relatively modest cortical atrophy progression. Random forest analysis identified the most discriminative TOIs and SOIs including the uncinate fasciculus and the amygdala.

Conclusions

Our findings demonstrate a similar pattern of structural and microstructural changes in bvFTD and ALS‐FTD, with a specific involvement of the corticospinal tract for ALS‐FTD, and support the utility of combined DTI and ABV in tracking disease progression across the FTLD spectrum.

LETTER TO THE EDITOR

Letter to the Editor: “Headache After Sealing of Cerebrospinal Fluid Leaks in Patients With Spontaneous Intracranial Hypotension”

ORIGINAL ARTICLE

Background

Insurance data allow insights into dispensations of medications. This retrospective study over 49 months examined dispensations of monoclonal antibodies against calcitonin gene‐related peptide (CGRP‐mAbs).

Methods

Using nationwide insurance data, we examined dispensations of erenumab, fremanezumab, or galcanezumab from September 1, 2018 to September 30, 2022. We examined the duration of treatment and breaks (Kaplan–Meier curves, medians, quartiles), persistence (proportion of days covered), and switches, acute medications, and other preventatives.

Results

Of 8.8 million persons, 8934 were at least once dispensed a CGRP‐mAb (83.5% women, median age 45 years). Median individual follow‐up time was 710 days, median duration of treatment with any CGRP‐mAb was 297 days, 42.9% had CGRP‐mAbs for at least 1 year. Median duration of treatment with the first‐ever CGRP‐mAb was 327 days; 63.4% experienced a therapy break. Within 1 year after stopping, 53.5% resumed the same CGRP‐mAb, 16.9% another CGRP‐mAb, 29.6% did not resume any CGRP‐mAb; 13.7% started a second CGRP‐mAb and 1.7% a third. 22% definitively stopped therapy within their follow‐up. Dispensation of triptans decreased during and after therapy with CGRP‐mAbs; dispensation of other acute prescription medications was low without change. 11.4% had other preventatives before and 2.4% during CGRP‐mAb therapy. The proportion of days covered was 96%.

Conclusions

In this nationwide study persistence with CGRP‐mAbs was excellent; dispensations of triptans and other preventatives decreased during CGRP‐mAb therapy. Therapy breaks were common, but the majority resumed CGRP‐mAbs, which indicates the need for long‐term prophylaxis.

SHORT COMMUNICATION

Background

Annexins are a family of calcium‐dependent membrane‐binding proteins implicated in membrane repair and inflammation, yet their immunoreactivity patterns in neuromuscular disorders remain poorly characterized. This study systematically examined the immunoreactivity profiles of annexins A1, A2, A4, A5, A6, A7, and A11 across various muscular dystrophies, including muscular dystrophies, inflammatory myopathies, lipid storage myopathy (LSM), and amyotrophic lateral sclerosis (ALS).

Methods

Muscle biopsies from patients with dysferlinopathy, Duchenne/Becker muscular dystrophy (DMD/BMD), myotonic dystrophy type 1 (DM1), oculopharyngeal muscular dystrophy (OPMD), facioscapulohumeral muscular dystrophy (FSHD), LSM, inflammatory myopathies, and ALS, along with controls, were analyzed. Immunofluorescence and immunoblot assays were used to assess annexin localization and abundance, and quantitative immunoreactivity levels were statistically compared with controls.

Results

Dysferlinopathy showed a distinct upregulation of multiple annexins (A1, A2, A4, A5, A6, and A7). These annexins were primarily localized to the extracellular matrix, with additional cytoplasmic accumulation in atrophied fibers. Annexin A6 was strongly associated with the sarcolemma, while annexin A7 was diffusely distributed. In contrast, other myopathies such as OPMD and FSHD exhibited reduced or unchanged annexin immunoreactivity. Inflammatory myopathies partially mirrored the dysferlinopathy pattern, though annexin A2 levels were lower. ALS samples displayed minimal immunoreactivity, restricted to focal cytoplasmic annexin A1 and sparse sarcolemmal annexin A6.

Conclusions

These findings reveal a unique annexin signature in dysferlinopathy, suggesting a potential involvement in membrane repair and inflammatory modulation. The differential expression across disorders highlights the diverse roles of annexins in muscle pathophysiology and supports their utility as diagnostic biomarkers and therapeutic targets.

ORIGINAL ARTICLE

Background

Aphasia after acute stroke is a frequent and disabling condition, impairing communication and quality of life. We investigated whether tablet‐assisted Speech and Language Therapy (SLT) using the Neolexon application is superior to standard SLT in acute stroke patients.

Methods

In this prospective, open‐label, randomized, controlled clinical trial, patients with acute post‐stroke aphasia were recruited from one stroke center and two neurorehabilitation clinics in Germany. Participants were stratified by aphasia severity and randomized to tablet‐assisted SLT ( = 53) or standard SLT ( = 51), initiated during inpatient care and continued in rehabilitation (30 min/Day). The primary outcome was the change in the Bielefelder Aphasia Screening (BIAS) percentile rank from baseline to 90 days. Secondary outcomes included frequency and duration of self‐training.

Results

From 07/2021 to 09/2024, 4097 patients were screened and 104 randomized (mean age 74.4 ± 11.2 years; 51.9% female). No significant difference in BIAS change was found at 90 days (18 vs. 14). The trial was stopped early for futility. The intervention group engaged in self‐directed training more frequently (37.7% vs. 21.6%) and trained longer (10 vs. 4 h). Subgroup analyses showed benefits of tablet‐assisted SLT in patients with mild ( = 15.51; 95% CI −1.67 to 32.69) and moderate aphasia ( = 23.58; 95% CI −4.48 to 51.65), and those with a National Institutes of Health Stroke Scale of less than 5 ( = 21.69; 95% CI 5.54–37.84).

Conclusions

Although underpowered to demonstrate overall superiority, tablet‐assisted SLT showed potential benefits in patients with mild to moderate aphasia and less severe strokes in the acute setting.

REVIEW ARTICLE

Background and Objectives

Infectious encephalitis is a serious global health problem linked to high rates of mortality and morbidity. However, clinical and laboratory factors that impact neurological outcomes following infectious encephalitis remain poorly understood. Accordingly, we undertook a systematic review and meta‐analysis of clinical and laboratory factors influencing neurological outcomes following infectious encephalitis.

Methods

We searched MEDLINE and EMBASE from inception to 25th September 2023 for observational studies that reported on neurological outcomes at discharge or at ≥ 6 months. We assessed the prognostic value of a priori selected clinical and laboratory‐based features by estimating pooled risk ratios (RRs) through a random‐effects meta‐analysis. The statistic was used to assess heterogeneity. This study is registered with PROSPERO (CRD42023485045).

Results

There were several key findings. First, immunocompromised status, status epilepticus, and Glasgow coma scale of < 8 during initial admission were significantly associated with poor neurological outcomes both at discharge and ≥ 6 months after infectious encephalitis onset. Second, CSF leucocytosis [RR: 0.83 95% CI: 0.69–0.98,  = 0.03,  = 5,  = 0%] conferred better neurological outcomes while elevated CSF protein [RR: 1.25 95% CI: 1.07–1.46,  = 0.006,  = 7,  = 0%] was linked to worse neurological outcomes at discharge. Third, there was no significant association between adjunct steroid therapy and neurological outcomes at discharge and ≥ 6 months.

Discussion

This is the first systematic review and meta‐analysis to investigate prognostic factors linked to neurological outcomes following infectious encephalitis. The results highlight the prognostic value of a range of easily accessible clinical and laboratory parameters.

ORIGINAL ARTICLE

Objectives

To explore the clinicopathological features and treatment prognosis including death, relapse and remission of dermatomyositis (DM) based on myositis‐specific autoantibody (MSAs) stratification.

Methods

Patients with DM come from a provincial neuromuscular center in northern China. Patients who underwent biopsy from 2010 to 2023 were collected, and the follow‐up time was all more than 6 months. Clinical characteristics, serum samples, and muscle biopsies were collected. Kaplan–Meier analysis, Cox regression, and competing risk model were used for analysis.

Results

Our study included 140 patients with DM. Among the 25 juvenile patients, 9 (36%) were anti‐NXP2 antibody positive. About 80.95% of the patients with anti‐TIF1‐γ antibodies had neck flexion weakness. Patients with anti‐Mi‐2 antibodies showed a predominance of severe muscle fiber necrosis/regeneration (76.19%) rather than perifascicular atrophy (14.29%). Compared to the seronegative subgroup, the short‐ and long‐term risks of death were higher in anti‐TIF1‐γ‐positive patients, and the 3‐year risk of death was higher in anti‐MDA5 patients. The short‐ and long‐term dangers of relapse were consistently higher in anti‐Mi‐2‐positive patients, with a higher 3‐year relapse risk in the anti‐NXP2 subgroup. In the case of death as a competing risk of relapse, patients with anti‐Mi‐2 and patients with anti‐NXP2 had higher short‐ and long‐term risks of relapse. No difference was found in the clinical remission rate based on the DM‐MSA stratification.

Conclusion

Evaluating the characteristics and prognosis of DM subgroups based on serum MSA stratification is helpful for patient management and treatment strategies.

ORIGINAL ARTICLE

Background

Obesity increases the risk of diabetic peripheral neuropathy (DPN). However, past studies have typically assessed obesity using anthropometric measurements. Our primary aim determined associations between detailed obesity measurements, DPN, and painful DPN (pDPN). Our secondary aim compared the discriminatory capabilities of these measurements.

Methods

We performed a cross‐sectional study of persons with diabetes. Obesity was assessed using anthropometrics, bioelectrical impedance (BIA), abdominal MRIs (aMRI), and/or dual x‐ray absorptiometry (DEXA). Obesity measurements were categorized as measuring general, central, or peripheral obesity, or the central‐peripheral obesity ratio. DPN was defined as Michigan Neuropathy Screening Instrument questionnaire ≥ 4. Within this group, pDPN was defined as bilateral foot pain in the prior 3 months. Areas under receiver operating characteristic curves (AUC) determined discriminatory capabilities of obesity measurements for DPN, stratified by sex.

Results

We identified 7090 persons with diabetes that completed DPN assessments (mean age: 58.4, 39.6% female), of which 100.0% completed anthropometrics, 98.4% completed BIA, 3.9% completed aMRI, and 2.3% completed DEXA. 1271 (17.9%) had DPN with 28.1% experiencing pDPN. Logistic regression revealed 13/13 anthropometric, 27/29 BIA, 21/34 DEXA, and 8/14 aMRI measurements associated with DPN, but none associated with pDPN. For males, median AUCs for DPN were similar regardless of location (central: 0.88, 0.89, general: 0.89, peripheral: 0.88, central–peripheral ratio: 0.87), whereas for females, central obesity (0.92) had the largest AUC for DPN, followed by general (0.88), peripheral (0.84), and central–peripheral obesity ratio (0.78).

Conclusions

Obesity is associated with DPN, but not pDPN. For males, obesity distribution did not differentially discriminate DPN, whereas for females, central obesity best discriminated DPN.

ORIGINAL ARTICLE

Background

Inflammation is increasingly recognized in the pathogenesis of diabetic neuropathy (DN). Circulating miR‐27a‐3p levels are closely related to inflammation and increased in patients with diabetic nephropathy and retinopathy. miR‐27a‐3p has a predicted binding site in the 3 UTR of Netrin‐1 mRNA, an anti‐inflammatory nerve growth factor whose levels correlate with small nerve fiber loss in patients with DN.

Methods

Eighty‐two participants with (DN+) and without (DN‐) small nerve fiber damage and 45 healthy controls underwent measurement of plasma miR‐27a‐3p, PBMC levels of NF‐kB and NLRP3, serum Netrin‐1, TNFα, IL‐1β, and IL‐10 levels.

Results

Corneal nerve fiber density (CNFD), branch density (CNBD), and fiber length (CNFL) were significantly lower in the DN‐ and DN+ groups compared to controls ( < 0.001). Plasma miR‐27a‐3p and PBMC NF‐kB and NLRP3 expression were significantly higher in the DN+ group, and miR‐27a‐3p identified DN+ with an area under the curve (AUC) of 89%. Serum Netrin‐1 and IL‐10 levels were lower, while TNFα and IL‐1β levels were higher in the DN+ group. miR‐27a‐3p levels correlated negatively with CNFL and Netrin‐1 and positively with NF‐kB and NLRP3.

Conclusion

miR‐27a‐3p levels are elevated in subjects with DN and correlate with markers of inflammation, Netrin‐1, and corneal nerve loss. miR‐27a‐3p could be a biomarker for DN, and miR‐27a‐3p/Netrin‐1 crosstalk may be a promising therapeutic target for DN.

ORIGINAL ARTICLE

Background

Abnormal temporal dispersion (TD) poses a significant challenge to the detection of motor conduction block (CB) in routine electrodiagnostic practice. However, the most recent electrodiagnostic criteria do not explicitly address the relationship between these phenomena. This study aimed to evaluate the impact of motor conduction velocity (MCV) slowing and abnormal TD on motor CB, and to establish TD‐based electrodiagnostic criteria for the accurate identification of motor CB.

Methods

Electrophysiological data from 35 patients diagnosed with chronic immune‐mediated demyelinating neuropathies, according to the EAN/PNS electrodiagnostic criteria, were retrospectively analyzed. Linear regression models were employed to examine the relationship between MCV changes, TD, and proximal compound muscle action potential (p‐CMAP) amplitude reduction.

Results

p‐CMAP amplitude reduction was significantly associated with TD and MCV changes in the median, ulnar, and peroneal nerves ( < 0.001). Moreover, increases in TD accounted for 46.9% to 56.2% of the variability in p‐CMAP amplitude reduction. In contrast, in the tibial nerve, TD explained only 21.8% of the observed variability. The regression analyses demonstrated that true motor CB could not be defined when abnormal TD exceeded 140% in the median nerve, 85% in the ulnar nerve, 185% in the peroneal nerve, and 240% in the tibial nerve. Furthermore, in the absence of abnormal TD, the cut‐off values for detecting definite motor CB ranged from 40% to 60%, depending on the nerve examined.

Conclusions

Even a marked decline in p‐CMAP amplitude may not necessarily reflect true motor CB. Reliable determination of definite motor CB requires stringent, nerve‐specific electrodiagnostic criteria that take abnormal TD into account.

EDITORIAL

The Sleep Puzzle: Linking Glymphatic Function to Cognitive Decline

ORIGINAL ARTICLE

Background

Skin biopsies and seed amplification assays (SAA) provide a sensitive and potentially quantitative method to detect alpha‐synuclein (a‐syn) aggregation in peripheral nerve fibers in Parkinson's disease (PD). Relating to the previously published hypothesis that PD may either originate in the peripheral (body‐first) or central (brain‐first) nervous system, we investigated whether patients with clinical features that have been reported to be associated with a suspected body‐first subtype of PD exhibit higher levels of a‐syn aggregation in dermal nerve fibers compared to those without these features. Patients with isolated REM sleep behavior disorder (iRBD) representing a suspected premotor stage of body‐first PD were studied in comparison to the PD cohort.

Methods

Patients were categorized on the basis of clinical features, and SAA parameters such as lag time, number of positive curves, and titers were analyzed and correlated with clinical features.

Results

Although patients with clinical features of suspected body‐first PD showed slightly higher titers, significant differences were mainly observed between iRBD patients and PD patients.

Conclusions

Our data suggest that widespread α‐syn aggregation in advanced PD limits the use of SAA in skin biopsies for subtype differentiation.

ORIGINAL ARTICLE

Background

Asymptomatic degenerative cervical cord compression (ADCC) represents a premyelopathic stage of degenerative cervical myelopathy (DCM), with high prevalence in older age and unclear management. Contact heat‐evoked potentials (CHEPs) assess the integrity of the thermo‐algesic somatosensory pathway and have shown the highest sensitivity among neurophysiological methods in detecting dysfunction in the centromedial and anterior spinal cord in DCM.

Methods

This cross‐sectional cohort study evaluated the utility of upper extremity dermatomal C4, C6 and C8 CHEPs (dCHEPs) compared to standard neurophysiological methods—median and tibial nerves somatosensory evoked potentials (SEPs), upper and lower extremity motor evoked potentials (MEPs), and electromyography (EMG)—for detecting subclinical cervical cord dysfunction in ADCC. Two cohorts were included: 82 ADCC patients (mean age 53.7 ± 9.8 years; 53 females) and 10 DCM patients (mean age 64.0 ± 7.9 years; 4 females). All underwent bilateral dCHEPs (C4, C6, C8), SEPs, MEPs, and EMG (C5–C8 myotomes).

Results

dCHEPs abnormalities were found in 50% of ADCC patients, exceeding the rates for SEPs (32.1%), MEPs (21.8%), and EMG (13.9%). In 20.7%, dCHEPs were the only abnormal neurophysiological finding. In the DCM cohort, dCHEPs were abnormal in 80%, and were the only abnormality in 20%. In both groups, abnormalities were most frequent in the C8 dermatome.

Conclusions

dCHEPs demonstrated superior sensitivity in detecting cervical cord dysfunction, not only in DCM but also in ADCC. As a functional complement to MRI, they may aid in identifying early spinal cord involvement. Their prognostic role in ADCC warrants further study.

ORIGINAL ARTICLE

Background

Inherited prion diseases follow autosomal dominant inheritance with a theoretical 50% transmission risk per pregnancy. Transmission ratio distortion (TRD)—deviation from expected Mendelian ratios—has been documented in other genetic disorders but never systematically studied in prionopathies. We aimed to determine whether TRD occurs in families with inherited prion diseases—specifically familial Creutzfeldt‐Jakob disease due to the p.E200K variant and fatal familial insomnia caused by the p.D178N variant—and to assess whether transmission patterns differ by parent sex.

Methods

We analyzed 24 pedigrees (12 per variant) comprising 65 nuclear families with 151 offspring. Transmission ratios were calculated and compared to expected 50% Mendelian inheritance using generalized estimating equations. Sex‐specific transmission patterns were evaluated for both maternal and paternal carriers.

Results

Overall transmission rates were 67.1% for p.D178N (95% CI: 56.3%–77.9%,  < 0.05) and 70.5% for p.E200K (95% CI: 60.4%–80.6%,  < 0.001), representing deviations from expected Mendelian ratios. Sex‐specific analysis revealed maternal transmission of 67.5% for p.D178N ( < 0.05) and 67.3% for p.E200K ( < 0.05). Paternal transmission showed 66.7% for p.D178N ( = 0.056) and 78.3% for p.E200K ( < 0.05), with the latter showing pronounced paternal bias.

Conclusions

This study provides the first systematic evidence of TRD in inherited prion diseases, with both variants showing clinically meaningful deviations from Mendelian inheritance. These findings challenge current genetic counseling assumptions of 50% inheritance risk and suggest that actual transmission probabilities are 17%–21% higher than traditionally estimated. Risk assessment protocols for prion diseases require updating to incorporate variant‐specific and sex‐specific transmission patterns, particularly the strong paternal bias observed with p.E200K.

ORIGINAL ARTICLE

Background

Spinal and bulbar muscular atrophy (SBMA) is a hereditary neuromuscular disorder linked to gene mutations, often associated with metabolic abnormalities. We aimed to investigate the incidence of fragility fractures and the underlying mechanisms in SBMA.

Methods

Consecutive genetically confirmed SBMA patients and healthy controls (HC) were enrolled. We surveyed fracture history and assessed motor function, bone metabolism markers, and bone mineral density (BMD) using dual‐energy X‐ray absorptiometry. Longitudinal BMD changes were also analyzed between SBMA patients and HC.

Results

A total of 109 SBMA patients and 21 HC were included. Fragility fractures in SBMA patients were mainly observed in cortical bone‐dominant regions. Their lower limb BMD was significantly reduced (SBMA 1.10 g/cm, HC 1.19 g/cm;  < 0.05) and further decreased overtime. Despite low bone resorption markers, bone formation markers showed no difference between the groups, suggesting that SBMA patients exhibit characteristics of low turnover osteoporosis. Serum 25‐hydroxyvitamin D levels were lower in SBMA patients than in HC (15.4 ng/mL vs. 19.4 ng/mL;  < 0.01). Longitudinal analysis revealed that SBMA patients had a higher incidence of fragility fractures than HC (log‐rank test,  < 0.05), with the first fragility fracture occurring 10 years after the onset of muscle weakness. Low baseline BMD was a predictor of fragility fractures (adjusted OR = 0.32; 95% CI: 0.17–0.60;  < 0.05).

Conclusions

SBMA patients have a high fragility fracture incidence, particularly in cortical bone, with a progressive BMD decrease. Low bone turnover and vitamin D deficiency are associated with these fractures.

REVIEW ARTICLE

Background

We aimed to systematically review the evidence for associations between the known modifiable risk factors and dementia based on Mendelian randomisation (MR) studies.

Method

Five databases were searched from inception to April 2024 investigating the association between the 12 risk factors identified in the Lancet Commission and dementia. Evaluable analyses were categorized into one of four levels (robust, probable, suggestive, insufficient) based on estimate significance level and concordance of direction of effect between main and sensitivity analyses. Evidence from clinically diagnosed dementia outcomes was synthesized separately from proxy outcomes. A post hoc sensitivity analysis excluded estimates with concerns over construct validity.

Results

A total of 47 studies were included, representing 240 MR associations (185 unique and evaluable). Over half (73.5%) of evaluable analyses were graded as providing insufficient evidence for a causal association. Among clinically diagnosed outcomes, the strongest evidence was for educational attainment (mainly probable evidence in a protective direction) and type 2 diabetes‐related dysfunction (probable evidence in the risk direction). Smoking showed probable evidence of a protective association. Other risk factors, produced inconclusive or insufficient evidence. Proxy outcome analyses yielded weaker findings; in particular, the association between education and Alzheimer's disease reversed direction.

Conclusion

MR evidence for most Lancet Commission risk factors remains insufficient or inconclusive. The most consistent support for causal associations was observed for lower educational attainment and type 2 diabetes. Null findings should be interpreted cautiously given limitations in GWAS phenotyping, sample composition, and MR methodology.

ORIGINAL ARTICLE

Background

Following COVID‐19, an increased risk of neurological and psychiatric sequelae has been reported. Viral illnesses commonly trigger functional neurological disorder (FND). However, mechanisms beyond immediate biological effects may contribute to FND after COVID‐19. While FND cases have been observed after COVID‐19, the overall risk and contributing factors remain unclear. In this retrospective cohort study, we compared the rates of FND post‐COVID‐19 to other respiratory tract infections (RTIs), assessed the influence of disease severity, and the characteristics of newly diagnosed patients.

Methods

We used TriNetX, a global electronic health record network. In total, 2,740,094 COVID‐19 cases and 1846 post‐COVID‐19 FND cases were analysed. We compared FND incidence between 2 weeks and 6 months after COVID‐19 to other RTIs and across cohorts of varying COVID‐19 severity. Characteristics of individuals with new diagnoses of FND and migraine following COVID‐19 were compared.

Results

The incidence of FND was higher in COVID‐19 patients with records of hospitalisation (OR 2.165; 95% CI 1.691–2.773) and emergency department visits (OR 1.412; 95% CI 1.069–1.864). Incidence was higher following COVID‐19 compared to other RTIs, both in the first 2 years of the pandemic (0.033 vs. 0.021%, OR 1.555, 95% CI 1.271–1.902) and subsequently (0.038 vs. 0.027%, OR 1.394, 95% CI 1.173–1.657). Medical, neurological, and psychiatric comorbidities were more common in newly diagnosed post‐COVID‐19 FND compared to migraine.

Conclusions

New‐onset FND appears more likely after COVID‐19 than other RTIs. Both the severity of the triggering illness and pre‐existing individual vulnerability may contribute to the development of FND.

ORIGINAL ARTICLE

Background

This post hoc analysis examined the reduction in monthly headache days (MHDs) by frequency category shifts and associated improvements following eptinezumab treatment.

Methods

The DELIVER trial evaluated eptinezumab in adults with migraine for whom 2–4 previous preventive treatments failed. During a 24‐week, double‐blind, placebo‐controlled period followed by a 48‐week extension period, participants received IV eptinezumab 100 mg, 300 mg, or placebo every 12 weeks, with all receiving eptinezumab beginning Week 25 (dose‐blinded). Participants were categorized by MHD frequency: > 14, 8–14, 4 to < 8, 1 to < 4, 0. MHD category shifts were evaluated in the total population and several subgroups (including participants with > 14 baseline MHDs and early ≥ 50% responders). In participants reporting < 8 MHDs after all doses, the associated changes in headache intensity and disease status were evaluated.

Results

Of randomized participants, 88% (782/890) completed the trial. The percentage of participants randomized initially to eptinezumab who reported < 4 MHDs was 23% (138/592) over Weeks 1–12 and 47% (236/498) over Weeks 61–72; 9% reported 0 MHDs after the final dose. Of participants randomized initially to eptinezumab who shifted from ≥ 8 MHDs at baseline to < 8 over Weeks 1–12, 71% (170/241) reported < 8 MHDs for the rest of the trial; of those who shifted from > 14 to < 8 MHDs, 66% (49/74) reported < 8 MHDs for the rest of the trial. Reduction to < 8 MHDs was associated with robust improvements in headache intensity and disease burden.

Conclusions

Eptinezumab was associated with sustained reduction in MHD category, with some achieving headache/migraine freedom in patients with a history of preventive treatments that failed.

Trial Registration

(identifier: NCT04418765; ) and EudraCT (identifier: 2019‐004497‐25; )

ORIGINAL ARTICLE

Background and Aims

Previous randomized trials, such as CHANCE and POINT, have shown that dual antiplatelet therapy (DAPT) reduces ischemic event recurrence. However, its effectiveness depends on accurate dosage and timely administration. This study is a comprehensive quality assessment of the implementation of the DAPT protocol—specifically, treatment initiation within 48 h of symptom onset in patients with mild stroke or high‐risk TIA—at our center.

Methods

For this single‐center, retrospective analysis we screened all 11,180 consecutive patients from the Helsinki Stroke Quality Registry (HSQR) treated at the emergency department between 1st of January 2019 and 25th of January 2023. Patients with DAPT (ASA and clopidogrel) within 2 weeks of admission were included. Patients treated with i.v. thrombolysis, thrombectomy or if already on DAPT prior to admission were excluded. We analyzed the time of DAPT initiation, patient diagnoses and risk scores (NIHSS and ABCD).

Results

Of 11,180 patients screened, 299 met the inclusion criteria. Among them, 263 (88.0%) had a final diagnosis of ischemic stroke or TIA, supporting DAPT use. Risk scores were documented in 193 (73.4%), and 197 (65.9%) initiated DAPT within 48 h of symptom onset per our institutional protocol. Overall, 137 (45.8%) fully adhered to all protocol criteria.

Conclusions

Fewer than half (45.8%) of patients fully adhered to the HUS protocol, and 65.9% initiated DAPT within 48 h from symptom onset. We propose that DAPT should be considered as part of the acute stroke treatment protocol for eligible patients to minimize delays in treatment initiation.

REVIEW ARTICLE

Background

In patients with giant cell arteritis (GCA), 2.8%–8.2% present with ischemic stroke (IS) or transient ischemic attack (TIA). GCA diagnosis may be overlooked, and immunosuppressive treatment delayed if typical symptoms are absent or if a common cause of IS coexists. This study aimed to identify potential markers of GCA through clinical evaluation and baseline investigation of IS/TIA patients.

Methods

Two authors independently conducted a scoping review using MEDLINE and EMBASE databases to identify patients diagnosed with GCA after presenting with IS/TIA. All articles, including the gray literature, were considered from January 2000 onwards if individualized data were described. Only cases of IS/TIA with GCA later diagnosed as the etiology were included for analysis.

Results

A total of 101 publications were included, pooling data on 141 patients for analysis. The mean age was 73.6 years, and 61 were women. Patients experienced either single (56.0%) or multiple IS/TIA events (44.0%). Associated symptoms included GCA‐related pain, such as headaches (50.4%), constitutional symptoms (47.5%), and temporal artery inflammation (27.0%). Neurological deficits involved corticospinal tracts (41.8%), and cerebellar functions (53.2%). Most patients had clinical or radiological evidence of vertebrobasilar involvement (83.7%). Multifocal involvement of the vertebrobasilar and carotid territories was supported when combining clinical‐radiological manifestations (41.1%). Recurrent events were common (44.0%).

Conclusion

GCA should be considered in IS/TIA patients aged ≥ 50 years with vertebrobasilar or multiterritorial involvement, or recurrent IS/TIA despite secondary prevention.

ORIGINAL ARTICLE

Background

Evidence suggests signs and symptoms may emerge years before the clinical onset of multiple sclerosis (MS). We investigated secondary healthcare use and medication dispensations before MS onset.

Methods

Using linked administrative data, we analyzed a neurologist‐diagnosed MS clinical cohort and an algorithm‐defined administrative cohort in Sweden (2001–2019). People with MS (PwMS) were matched to up to five non‐MS comparators by sex, birth year, residency location, and residency duration before the index date (clinical: symptom onset; administrative: first MS/demyelinating diagnosis code). Annual outpatient visits and hospitalizations by diagnosis codes across 19 years pre‐index, and dispensed medications by anatomical and therapeutic classifications across 14 years pre‐index were compared.

Results

The clinical cohort included 7604 PwMS and 37,974 matched comparators (median age at symptom onset = 35.5; 68.5% females). In the 5 years pre‐index, outpatient visits were 11%–73% higher among PwMS for disturbances of sense organs, nervous, musculoskeletal, digestive, and genitourinary systems, mental health/behavior, and ill‐defined symptoms/signs, with visits related to sense organs elevated up to 6 years. Hospitalizations were often elevated in the year pre‐index. Dispensations of nervous system‐related, musculoskeletal, blood‐related, metabolic, sensory, respiratory, and dermatological agents were elevated by 6%–22% in the 5 years pre‐index, with elevations in nervous system‐related and musculoskeletal agents extending up to 6–9 years pre‐index. Findings were similar in the administrative cohort with greater magnitudes and longer durations pre‐index.

Conclusions

We observed increased hospital, outpatient, and prescription utilization for multiple body systems 6–9 years pre‐MS onset. These patterns provide a more comprehensive picture of the MS prodrome.

REVIEW ARTICLE

Background

Anti‐IgLON5 disease is now considered a complex and heterogeneous neurological disorder with sleep, movement, and neuroimmunological as well as neurodegenerative aspects. The aim of this systematic review and meta‐analysis was to entail the whole clinical spectrum as well as laboratory characteristics, therapeutic interventions and reported outcomes of anti‐IgLON5 disease.

Methods

The electronic databases PubMed/MEDLINE, Web of Science and Semantic Scholar were searched for case reports and case series on anti‐IgLON5 disease published until July 31, 2024. For inclusion, studies had to report on patients with a positive IgLON5 antibody titer in serum or CSF and be published in English in a peer‐reviewed journal. For meta‐analyses, only case series with  ≥ 10 patients were considered. The risk of bias was assessed with the JBI critical appraisal tool.

Results

A total of 285 patients ( case series/case reports = 85) with anti‐IgLON5 disease were included in this systematic review. Sleep abnormalities ( = 218; 76.5%), bulbar dysfunction ( = 175; 61.4%) and movement disorders ( = 160; 56.1%) were most frequently reported. The prevalence of IgLON5 antibodies in the serum was 99.6% ( reported = 276).

Conclusion

Based on our results, anti‐IgLON5 disease should be considered in patients presenting with sleep disorders and additional neurological symptoms that might resemble other diseases but do not fulfill the respective diagnostic criteria. Testing for antibodies in serum has a high sensitivity in this disorder. A limitation of this study is that it was not preregistered.

LETTER TO THE EDITOR

Uncovering Hidden Profiles: From Pain‐Centric to Multi‐Symptom Small Fiber Neuropathy

LETTER TO THE EDITOR

Olfactory Dysfunction and/or RBD for Mapping Parkinson's Disease Subtypes?

ORIGINAL ARTICLE

Background

Cerebrospinal fluid (CSF) analysis is key to diagnosing multiple sclerosis (MS). In particular, the presence of CSF‐specific oligoclonal bands (OCB) is examined alongside differential diagnostic aspects. This study aims to investigate the diagnostic value of OCB in MS compared to other neurological disorders.

Methods

Patients who presented to the Department of Neurology of the Medical University of Vienna between January 1, 2004 and December 31, 2020, due to neurological complaints and underwent lumbar puncture (LP) for diagnostic purposes were included in this retrospective analysis. Exclusion criteria were incomplete laboratory data and/or a missing final diagnosis.

Results

Of 5744 patients who underwent LP, 5225 were available for analysis. Of these, 745 (14.3%) were diagnosed with MS, whereby CSF‐specific OCB showed a sensitivity of 92.8% and a specificity of 90.4%. While the positive predictive value (PPV) was merely 61.5%, the negative predictive value (NPV) yielded 98.7%. In comparison, OCB displayed low sensitivity rates for most other neurological disease groups. Of note, neuroborreliosis ( = 66) had a relatively high OCB positive rate of 70%, followed by CNS human immunodeficiency virus infections ( = 32) with 62.5%.

Conclusions

CSF‐specific OCB have a high sensitivity and specificity and a very high NPV for diagnosing MS. However, the PPV was lower in this cohort. These findings must be carefully considered when diagnosing MS and interpreting OCB, especially in the context of differential diagnostic workup.

ORIGINAL ARTICLE

Background

This study aimed at assessing the applicability of a symptom‐led staging system for primary progressive aphasia (PPA) based on retrospective medical records, as well as at exploring their demographic and clinical correlates.

Methods

75 PPA patients (10 semantic, 28 non‐fluent, 22 logopenic, and 16 mixed variants) were retrospectively staged according to the PPA Progression Planning Aid (PPA‐Squared) system, which stages the disease by accounting for clinical features along three axes: (1) Communication; (2) Non‐Verbal Thinking and Personality; (3) Personal Care and Well‐Being. The percentage of successfully staged patients was computed. The association between PPA‐Squared scores and demographic and clinical data was tested via non‐parametric tests. The predictive capability of PPA‐Squared scores towards survival was explored via a Mantel‐Cox test.

Results

89.3% of patients were successfully staged based on retrospective medical records. The PPA‐Squared was associated with the MMSE ( < 0.001), ADL ( = 0.021), and IADL scores ( < 0.001) and a set of second‐level cognitive measures tapping on attention, executive functions, language, long‐term memory, and visuo‐spatial abilities ( ≤ 0.049). No association was found between the PPA‐Squared and demographic features, symptom duration, PPA phenotype, the presence of motor involvement, and survival.

Discussion

The PPA‐Squared is a feasible and clinically valid tool for staging PPA patients based on their cognitive and functional .

LETTER TO THE EDITOR

Uncovering Hidden Profiles: From Pain‐Centric to Multi‐Symptom Small Fiber Neuropathy