Serum neurofilament light chain: a promising early diagnostic biomarker for hereditary transthyretin amyloidosis?

BACKGROUND AND PURPOSE: Hereditary transthyretin amyloidosis (ATTRv) is a life-threatening disease caused by mutations in the gene encoding transthyretin (TTR). The recent therapeutic advances have underlined the importance of easily accessible, objective biomarkers of both disease onset and progression. Preliminary evidence suggests a potential role in this respect for neurofilament light chain (NfL). In this study, the aim was to determine serum NfL (sNfL) levels in a late-onset ATTRv population and evaluate whether it might represent a reliable biomarker of disease onset (i.e., 'conversion' from the asymptomatic status to symptomatic disease in TTR mutation carriers). METHODS: In all, 111 individuals harbouring a pathogenic TTR variant (61 symptomatic ATTRv patients and 50 presymptomatic carriers) were consecutively enrolled. Fifty healthy volunteers were included as the control group. Ella™ apparatus was used to assess sNfL levels. RESULTS: Serum NfL levels were increased in ATTRv patients compared to both presymptomatic carriers and healthy controls, whilst not differing between carriers and healthy controls. An sNfL cut-off of 37.10 pg/mL could discriminate between asymptomatic and symptomatic individuals with high diagnostic accuracy (area under the curve 0.958; p < 0.001), sensitivity (81.4%) and specificity (100%). CONCLUSIONS: Serum NfL seems to be a promising biomarker of peripheral nerve involvement in ATTRv amyloidosis and might become a reliable, objective measure to detect the transition from the presymptomatic stage to the onset of symptomatic disease. Further longitudinal studies are needed to confirm such a role and determine whether it could equally represent a biomarker of disease progression and response to therapy.

Comparison of the diagnostic accuracy of the 2010 European Federation of Neurological Societies/Peripheral Nerve Society and American Association of Electrodiagnostic Medicine diagnostic criteria for multifocal motor neuropathy.

BACKGROUND AND PURPOSE: This study was undertaken to compare the sensitivity and specificity of the 2010 European Federation of Neurological Societies/Peripheral Nerve Society (EFNS/PNS) diagnostic criteria for multifocal motor neuropathy (MMN) with those of the American Association of Electrodiagnostic Medicine (AAEM). METHODS: Sensitivity and specificity of the two sets of criteria were retrospectively evaluated in 53 patients with MMN and 280 controls with axonal peripheral neuropathy, inflammatory demyelinating polyneuropathy, or amyotrophic lateral sclerosis. Comparison of the utility of nerve conduction studies with different numbers of nerves examined was also assessed. RESULTS: The 2010 EFNS/PNS criteria had a sensitivity of 47% for definite MMN and 57% for probable/definite MMN, whereas the AAEM criteria had a sensitivity of 28% for definite MMN and 53% for probable/definite MMN. The sensitivity of the AAEM criteria was higher when utilizing area compared to amplitude reduction to define conduction block. Using supportive criteria, the sensitivity of the 2010 EFNS/PNS criteria for probable/definite MMN increased to 64%, and an additional 36% patients fulfilled the criteria (possible MMN). Specificity values for definite and probable/definite MMN were slightly higher with the AAEM criteria (100%) compared to the EFNS/PNS criteria (98.5% and 97%). Extended nerve conduction studies yielded slightly increased diagnostic sensitivity for both sets of criteria without significantly affecting specificity. CONCLUSIONS: In our patient populations, the 2010 EFNS/PNS criteria demonstrated higher sensitivity but slightly lower specificity compared to the AAEM criteria. Extended nerve conduction studies are advised to achieve slightly higher sensitivity while maintaining very high specificity.

Assessment of diagnostic criteria for multifocal motor neuropathy in patients included in the Italian database.

BACKGROUND AND PURPOSE: This study aimed to assess the diagnostic criteria, ancillary investigations and treatment response using real-life data in multifocal motor neuropathy (MMN) patients. METHODS: Clinical and laboratory data were collected from 110 patients enrolled in the Italian MMN database through a structured questionnaire. Twenty-six patients were excluded due to the unavailability of nerve conduction studies or the presence of clinical signs and symptoms and electrodiagnostic abnormalities inconsistent with the MMN diagnosis. Analyses were conducted on 73 patients with a confirmed MMN diagnosis and 11 patients who did not meet the diagnostic criteria. RESULTS: The European Federation of Neurological Societies/Peripheral Nerve Society (EFNS/PNS) diagnostic criteria were variably applied. AUTHOR: When applying the American Association of Electrodiagnostic Medicine criteria, an additional 17% of patients fulfilled the criteria for probable/definite diagnosis whilst a further 9.5% missed the diagnosis. In 17% of the patients only compound muscle action potential amplitude, but not area, was measured and subsequently recorded in the database by the treating physician. Additional investigations, including anti-GM1 immunoglobulin M antibodies, cerebrospinal fluid analysis, nerve ultrasound and magnetic resonance imaging, supported the diagnosis in 46%-83% of the patients. Anti-GM1 immunoglobulin M antibodies and nerve ultrasound demonstrated the highest sensitivity. Additional tests were frequently performed outside the EFNS/PNS guideline recommendations. CONCLUSIONS: This study provides insights into the real-world diagnostic and management strategies for MMN, highlighting the challenges in applying diagnostic criteria.

Impact of 2021 European Academy of Neurology/Peripheral Nerve Society diagnostic criteria on diagnosis and therapy of chronic inflammatory demyelinating polyradiculoneuropathy variants.

BACKGROUND AND PURPOSE: There are different criteria for the diagnosis of different variants of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). The 2021 European Academy of Neurology/Peripheral Nerve Society (EAN/PNS) guidelines provide specific clinical criteria for each CIDP variant even if their therapeutical impact has not been investigated. METHODS: We applied the clinical criteria for CIDP variants of the 2021 EAN/PNS guidelines to 369 patients included in the Italian CIDP database who fulfilled the 2021 EAN/PNS electrodiagnostic criteria for CIDP. RESULTS: According to the 2021 EAN/PNS clinical criteria, 245 patients achieved a clinical diagnosis of typical CIDP or CIDP variant (66%). We identified 106 patients with typical CIDP (29%), 62 distal CIDP (17%), 28 multifocal or focal CIDP (7%), four sensory CIDP (1%), 27 sensory-predominant CIDP (7%), 10 motor CIDP (3%), and eight motor-predominant CIDP (2%). Patients with multifocal, distal, and sensory CIDP had milder impairment and symptoms. Patients with multifocal CIDP had less frequently reduced conduction velocity and prolonged F-wave latency and had lower levels of cerebrospinal fluid protein. Patients with distal CIDP more frequently had reduced distal compound muscle action potentials. Patients with motor CIDP did not improve after steroid therapy, whereas those with motor-predominant CIDP did. None of the patients with sensory CIDP responded to steroids, whereas most of those with sensory-predominant CIDP did. CONCLUSIONS: The 2021 EAN/PNS criteria for CIDP allow a better characterization of CIDP variants, permitting their distinction from typical CIDP and more appropriate treatment for patients.

Unclassified clinical presentations of chronic inflammatory demyelinating polyradiculoneuropathy.

BACKGROUND: To assess the ability of the 2021 European Academy of Neurology/Peripheral Nerve Society (EAN/PNS) clinical criteria for chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) to include within their classification the whole spectrum of clinical heterogeneity of the disease and to define the clinical characteristics of the unclassifiable clinical forms. METHODS: The 2021 EAN/PNS clinical criteria for CIDP were applied to 329 patients fulfilling the electrodiagnostic (and in some cases also the supportive) criteria for the diagnosis of CIDP. Clinical characteristics were reviewed for each patient not strictly fulfilling the clinical criteria ('unclassifiable'). RESULTS: At study inclusion, 124 (37.5%) patients had an unclassifiable clinical presentation, including 110 (89%) with a typical CIDP-like clinical phenotype in whom some segments of the four limbs were unaffected by weakness ('incomplete typical CIDP'), 10 (8%) with a mild distal, symmetric, sensory or sensorimotor polyneuropathy confined to the lower limbs with cranial nerve involvement ('cranial nerve predominant CIDP') and 4 (1%) with a symmetric sensorimotor polyneuropathy limited to the proximal and distal areas of the lower limbs ('paraparetic CIDP'). Eighty-one (65%) patients maintained an unclassifiable presentation during the entire disease follow-up while 13 patients progressed to typical CIDP. Patients with the unclassifiable clinical forms compared with patients with typical CIDP had a milder form of CIDP, while there was no difference in the distribution patterns of demyelination. CONCLUSIONS: A proportion of patients with CIDP do not strictly fulfil the 2021 EAN/PNS clinical criteria for diagnosis. These unclassifiable clinical phenotypes may pose diagnostic challenges and thus deserve more attention in clinical practice and research.

Risk of disease relapse, safety and tolerability of SARS-CoV-2 vaccination in patients with chronic inflammatory neuropathies.

BACKGROUND AND PURPOSE: The aim was to evaluate the risk of relapse after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination, and its safety and tolerability, in patients with chronic inflammatory neuropathies. METHODS: In this multicenter, cohort and case-crossover study, the risk of relapse associated with SARS-CoV-2 vaccination was assessed by comparing the frequency of relapse in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and multifocal motor neuropathy (MMN) patients who underwent or did not undergo vaccination. Frequency of relapse in the 3 months prior to and after vaccination, and safety and tolerability of SARS-CoV-2 vaccination, were also assessed. RESULTS: In all, 336 patients were included (278 CIDP, 58 MMN). Three hundred and seven (91%) patients underwent SARS-CoV-2 vaccination. Twenty-nine patients (9%) did not undergo vaccination. Mild and transient relapses were observed in 16 (5%) patients (13 CIDP, 3 MMN) after SARS-CoV-2 vaccination and in none of the patients who did not undergo vaccination (relative risk [RR] 3.21, 95% confidence interval [CI] 0.19-52.25). There was no increase in the specific risk of relapse associated with type of vaccine or diagnosis. Comparison with the 3-month control period preceding vaccination revealed an increased risk of relapse after vaccination (RR 4.00, 95% CI 1.35-11.82), which was restricted to CIDP patients (RR 3.25, 95% CI 1.07-9.84). The safety profile of SARS-CoV-2 vaccination was characterized by short-term, mild-to-moderate local and systemic adverse events. CONCLUSIONS: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination in CIDP and MMN patients does not seem to be associated with an increased risk of relapse at the primary end-point, although a slightly increased risk in CIDP patients was found compared to the 3 months before vaccination.

Effect of RNS60 in amyotrophic lateral sclerosis: a phase II multicentre, randomized, double-blind, placebo-controlled trial.

BACKGROUND AND PURPOSE: Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease with limited treatment options. RNS60 is an immunomodulatory and neuroprotective investigational product that has shown efficacy in animal models of ALS and other neurodegenerative diseases. Its administration has been safe and well tolerated in ALS subjects in previous early phase trials. METHODS: This was a phase II, multicentre, randomized, double-blind, placebo-controlled, parallel-group trial. Participants diagnosed with definite, probable or probable laboratory-supported ALS were assigned to receive RNS60 or placebo administered for 24 weeks intravenously (375 ml) once a week and via nebulization (4 ml/day) on non-infusion days, followed by an additional 24 weeks off-treatment. The primary objective was to measure the effects of RNS60 treatment on selected biomarkers of inflammation and neurodegeneration in peripheral blood. Secondary objectives were to measure the effect of RNS60 on functional impairment (ALS Functional Rating Scale-Revised), a measure of self-sufficiency, respiratory function (forced vital capacity, FVC), quality of life (ALS Assessment Questionnaire-40, ALSAQ-40) and survival. Tolerability and safety were assessed. RESULTS: Seventy-four participants were assigned to RNS60 and 73 to placebo. Assessed biomarkers did not differ between arms. The mean rate of decline in FVC and the eating and drinking domain of ALSAQ-40 was slower in the RNS60 arm (FVC, difference 0.41 per week, standard error 0.16, p = 0.0101; ALSAQ-40, difference -0.19 per week, standard error 0.10, p = 0.0319). Adverse events were similar in the two arms. In a post hoc analysis, neurofilament light chain increased over time in bulbar onset placebo participants whilst remaining stable in those treated with RNS60. CONCLUSIONS: The positive effects of RNS60 on selected measures of respiratory and bulbar function warrant further investigation.

SMN Deficiency Destabilizes ABCA1 Expression in Human Fibroblasts: Novel Insights in Pathophysiology of Spinal Muscular Atrophy.

The deficiency of survival motor neuron protein (SMN) causes spinal muscular atrophy (SMA), a rare neuromuscular disease that affects different organs. SMN is a key player in RNA metabolism regulation. An intriguing aspect of SMN function is its relationship with plasma membrane-associated proteins. Here, we provide a first demonstration that SMN affects the ATP-binding cassette transporter A1, (ABCA1), a membrane protein critically involved in cholesterol homeostasis. In human fibroblasts, we showed that SMN associates to ABCA1 mRNA, and impacts its subcellular distribution. Consistent with the central role of ABCA1 in the efflux of free cholesterol from cells, we observed a cholesterol accumulation in SMN-depleted human fibroblasts. These results were also confirmed in SMA type I patient-derived fibroblasts. These findings not only validate the intimate connection between SMN and plasma membrane-associated proteins, but also highlight a contribution of dysregulated cholesterol efflux in SMA pathophysiology.

Validation of the DYALS (dysphagia in amyotrophic lateral sclerosis) questionnaire for the evaluation of dysphagia in ALS patients.

BACKGROUND: Dysphagia is a common symptom during the trajectory of ALS, and it can significantly impact on the quality of life and prognosis of patients. Nowadays, no specific tool for the screening of dysphagia in ALS is validated, and the approach is heterogeneous across the Italian centres. OBJECTIVE: To validate the DYALS (dysphagia in amyotrophic lateral sclerosis) questionnaire, adapting the DYMUS (dysphagia in multiple sclerosis) questionnaire, for the assessment of dysphagia in ALS patients, in order to uniform the evaluations across the Italian ALS network. METHODS: We included 197 patients diagnosed with ALS following the El Escorial criteria, in sixteen Italian ALS centres between 1st December 2019 and 1st July 2020. For each patient, we collected clinical and demographic data and obtained ALSFRS-r score, ALSAQ-5 score, DYMUS score, and EAT-10 score. RESULTS: Across the 197 patients, the ratio M/F was 113/84, and the median age was 64 years (IQR 56-72.5). Bulbar patients were 20%, and spinal patients 80%. The median ALSFRSr total score of patients was 35 (IQR 28-39). DYALS score was statistically higher in bulbar ALS than in spinal ALS (median = 6, IQR 4.5-9 vs median = 1, IQR 0-5, z = 6.253, p < 0.0001). DYALS questionnaire showed a high internal consistency (Cronbach's alpha = 0.88). There was a statistically significant correlation between DYALS and EAT-10 (rho = 0.90, p < 0.0001). CONCLUSIONS: DYALS scale is reliable, manageable, and easily usable for the screening of dysphagia in ALS. It can be shared with all the Italian ALS centres in order to collect uniform data for therapeutic strategies and clinical trials.

Progression of Oropharyngeal Dysphagia in Amyotrophic Lateral Sclerosis: A Retrospective Cohort Study.

Little is known regarding the optimal timing of dysphagia assessment and PEG indication in amyotrophic lateral sclerosis (ALS). The study aims to investigate the progression of dysphagia in a cohort of ALS patients and to analyse whether there are variables linked to a faster progression of dysphagia and faster indication of PEG placement. A retrospective cohort study in 108 individuals with ALS. Fiberoptic endoscopic evaluation of swallowing was performed 6 monthly until PEG indication or death. Dysphagia severity and PEG indication were assessed using Penetration Aspiration Scale. Progression Index (PI) analysed the risk of disease progression (fast/slow) in relation to dysphagia onset and PEG indication. Patients were grouped based on ALS onset and PI. Person-time incidence rates were computed considering dysphagia onset and PEG indication from ALS symptoms during the entire observation period and have been reported as monthly and 6-month rates. Cox regression survival analysis assessed dysphagia and PEG risk factors depending on onset. Person-time incidence rates of dysphagia progression and PEG risk were increased based on type of ALS onset and PI. Patients with a fast progressing disease and with bulbar onset (BO) show statistically significant increased risk of dysphagia (BO 178.10% hazard ratio (HR) = 2.781 P < 0.01; fast 181.10% HR 2.811 P < 0.01). Regarding PEG risk, fast patients and patients with BO had a statistically significant increased risk (fast 147.40% HR 2.474 P < 0.01, BO 165.40% HR 2.654 P < 0.01). Fast PI predicts the likelihood of faster progression of dysphagia and PEG indication and should be included in multidisciplinary assessments and considered in the design of future guidelines regarding dysphagia management in ALS patients.Level of Evidence Level IV.

Nerve high-resolution ultrasonography in tangier disease.

INTRODUCTION: Tangier disease (TD) is an autosomal recessive disorder characterized by severe reduction in high-density lipoprotein and accumulation of cholesterol esters in peripheral nerves and other tissues. The aim of this study was to evaluate whether nerve high-resolution ultrasonography (HRUS) can detect morphological nerve changes in TD. METHODS: Three related patients of a previously reported Italian family with Tangier disease, carrying the Y1698X mutation in ABCA1, underwent clinical, neurophysiological, and quantitative nerve HRUS evaluation. Nerve HRUS data were compared with normal controls. RESULTS: Despite neurophysiological abnormalities, no quantitative HRUS abnormality was detected in peripheral nerves. DISCUSSION: Normalcy of HRUS in neurophysiologically abnormal nerves suggests possible subtle abnormalities that escape quantitative HRUS detection. Systematic studies in larger TD cohorts with different mutations are needed to confirm our findings. Muscle Nerve 59:587-587, 2019.

Italian recommendations for the diagnosis and treatment of myasthenia gravis.

Myasthenia gravis is a well-treatable disease, in which a prompt diagnosis and an adequate management can achieve satisfactory control of symptoms in the great majority of patients. Improved knowledge of the disease pathogenesis has led to recognition of patient subgroups, according to associated antibodies, age at onset and thymus pathology, and to a more personalized treatment. When myasthenia gravis is suspected on clinical grounds, diagnostic confirmation relies mainly on the detection of specific antibodies. Neurophysiological studies and, to a lesser extent, clinical response to cholinesterase inhibitors support the diagnosis in seronegative patients. In these cases, the differentiation from congenital myasthenia can be challenging. Treatment planning must consider weakness extension and severity, disease subtype, thymus pathology, together with patient characteristics and comorbidities. Since most subjects with myasthenia gravis require long-term immunosuppressive therapy, surveillance of expected and potential adverse events is critical. For patients refractory to conventional immunosuppression, the use of biologic agents is highly promising. These recommendations are addressed to non-experts on neuromuscular transmission disorders. The diagnostic procedures and therapeutic approaches hereafter described are largely accessible in Italy.

Acetylcholine receptors from human muscle as pharmacological targets for ALS therapy.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease affecting motor neurons that leads to progressive paralysis of skeletal muscle. Studies of ALS have revealed defects in expression of acetylcholine receptors (AChRs) in skeletal muscle that occur even in the absence of motor neuron anomalies. The endocannabinoid palmitoylethanolamide (PEA) modified the clinical conditions in one ALS patient, improving muscle force and respiratory efficacy. By microtransplanting muscle membranes from selected ALS patients into Xenopus oocytes, we show that PEA reduces the desensitization of acetylcholine-evoked currents after repetitive neurotransmitter application (i.e., rundown). The same effect was observed using muscle samples from denervated (non-ALS) control patients. The expression of human recombinant α1ß1γδ (γ-AChRs) and α1ß1εδ AChRs (ε-AChRs) in Xenopus oocytes revealed that PEA selectively affected the rundown of ACh currents in ε-AChRs. A clear up-regulation of the α1 subunit in muscle from ALS patients compared with that from non-ALS patients was found by quantitative PCR, but no differential expression was found for other subunits. Clinically, ALS patients treated with PEA showed a lower decrease in their forced vital capacity (FVC) over time as compared with untreated ALS patients, suggesting that PEA can enhance pulmonary function in ALS. In the present work, data were collected from a cohort of 76 ALS patients and 17 denervated patients. Our results strengthen the evidence for the role of skeletal muscle in ALS pathogenesis and pave the way for the development of new drugs to hamper the clinical effects of the disease.

Repetitive transcranial magnetic stimulation for chronic neuropathic pain in patients with bladder pain syndrome/interstitial cystitis.

AIMS: To evaluate the efficacy, safety, and tolerability of repetitive Transcranial Magnetic Stimulation (rTMS) associated with standard drug therapies for neuropathic pain that does not respond to pharmacological treatment alone in patients with Bladder Pain Syndrome/Interstitial Cystitis (BPS/IC). Secondary goals were to assess the effects of rTMS on Lower Urinary Tract Symptoms (LUTS) and Quality of Life (QOL). METHODS: Fifteen patients with BPS/IC were enrolled in this randomized, double-blind, sham stimulation-controlled, crossover study. Patients were treated for 2 weeks with either real-rTMS (for five consecutive days in 20-min sessions) or sham-rTMS (for five consecutive days in 20-min sessions). After a 6-week washout period, the patients who had previously undergone real-rTMS underwent sham-rTMS, and vice versa. Patients were rated at each visit by means of questionnaires on pain, urinary disturbances, depression, and QOL. RESULTS: The statistical analysis revealed significant effects of real-rTMS, when compared with sham-rTMS, on pain (in the VAS, Functional Neuropathic Pelvic Pain, Neuropathic Pain Symptom Inventory, McGill questionnaire, and Central Sensitization Inventory), urinary LUTS (in the Overactive Bladder Questionnaire score, bladder emptying, and daily urinary frequency), and QOL (in the subscores of the SF-36 related to physical pain and to emotional status). No serious adverse events were reported during the study. CONCLUSIONS: The results of this study show that rTMS applied with an H-coil over the M1 in the area corresponding to the pelvic region in patients with BPS/IC appears to improve chronic pelvic pain (CPP) and associated urinary disorders.

Chronic inflammatory demyelinating polyneuropathy: evaluation of the vestibular system with cervical and ocular vestibular evoked myogenic potentials.

PURPOSE: To investigate the possibility of vestibular damage in a group of patients suffering from chronic inflammatory demyelinating polyneuropathy (CIDP) using a diagnostic protocol including the caloric test, C-VEMPs and O-VEMPs. METHODS: Twenty patients suffering from CIDP (mean age 58.5 years, range 33-80 years; 4 women and 16 men) were investigated. To assess any eventual audio-vestibular involvement, all patients of the study underwent pure tone audiometry, Fitzgerald-Hallpike caloric vestibular test, C-VEMPs and O-VEMPs. RESULTS: In 11 patients with CIDP values of both O-VEMPs and C-VEMPs were either absent or abnormal. An absent trace at O-VEMPs testing occurred in 36% of these pathological patients, whereas an increase of n10 latency and amplitude was present in the other 64% . CONCLUSIONS: A specific diagnostic protocol including the caloric test, C-VEMPS, O-VEMPS, could be useful when employed for identifying vestibular damage in CIDP patients.

Glutamate-Mediated Blood-Brain Barrier Opening: Implications for Neuroprotection and Drug Delivery.

UNLABELLED: The blood-brain barrier is a highly selective anatomical and functional interface allowing a unique environment for neuro-glia networks. Blood-brain barrier dysfunction is common in most brain disorders and is associated with disease course and delayed complications. However, the mechanisms underlying blood-brain barrier opening are poorly understood. Here we demonstrate the role of the neurotransmitter glutamate in modulating early barrier permeability in vivo Using intravital microscopy, we show that recurrent seizures and the associated excessive glutamate release lead to increased vascular permeability in the rat cerebral cortex, through activation of NMDA receptors. NMDA receptor antagonists reduce barrier permeability in the peri-ischemic brain, whereas neuronal activation using high-intensity magnetic stimulation increases barrier permeability and facilitates drug delivery. Finally, we conducted a double-blind clinical trial in patients with malignant glial tumors, using contrast-enhanced magnetic resonance imaging to quantitatively assess blood-brain barrier permeability. We demonstrate the safety of stimulation that efficiently increased blood-brain barrier permeability in 10 of 15 patients with malignant glial tumors. We suggest a novel mechanism for the bidirectional modulation of brain vascular permeability toward increased drug delivery and prevention of delayed complications in brain disorders. SIGNIFICANCE STATEMENT: In this study, we reveal a new mechanism that governs blood-brain barrier (BBB) function in the rat cerebral cortex, and, by using the discovered mechanism, we demonstrate bidirectional control over brain endothelial permeability. Obviously, the clinical potential of manipulating BBB permeability for neuroprotection and drug delivery is immense, as we show in preclinical and proof-of-concept clinical studies. This study addresses an unmet need to induce transient BBB opening for drug delivery in patients with malignant brain tumors and effectively facilitate BBB closure in neurological disorders.

Effects of visual deprivation on primary motor cortex excitability: a study on healthy subjects based on repetitive transcranial magnetic stimulation.

We investigated whether rapid changes in visual input or dark adaptation modify primary motor cortex (M1) excitability in healthy subjects. Repetitive transcranial magnetic stimulation (rTMS), consisting of 10 stimuli delivered at 5 Hz at 120% of the resting motor threshold, was delivered over the M1 in 14 healthy volunteers. They were instructed to relax under eyes-open (EO) and eyes-closed (EC) resting conditions. Two experimental sessions were performed. In the first session, subjects were tested under both EO and EC conditions in order to determine whether short visual deprivation affected M1 excitability as tested through changes in the motor-evoked potential (MEP) amplitude during rTMS. In the second session, rTMS was delivered both under EO conditions with room lights on and after 30 min of blindfolding to evaluate the effects of prolonged visual deprivation on M1 excitability. Short-term visual deprivation lasting 2.5 s left the MEP facilitation unchanged during the 5-Hz rTMS trains, while 30 min of blindfolding significantly reduced MEP facilitation. Short-term visual deprivation did not significantly affect M1 excitability, whereas dark adaptation reduced rTMS-induced MEP facilitation, modulating motor cortical excitability.

A genome-wide association meta-analysis identifies a novel locus at 17q11.2 associated with sporadic amyotrophic lateral sclerosis.

Identification of mutations at familial loci for amyotrophic lateral sclerosis (ALS) has provided novel insights into the aetiology of this rapidly progressing fatal neurodegenerative disease. However, genome-wide association studies (GWAS) of the more common (∼90%) sporadic form have been less successful with the exception of the replicated locus at 9p21.2. To identify new loci associated with disease susceptibility, we have established the largest association study in ALS to date and undertaken a GWAS meta-analytical study combining 3959 newly genotyped Italian individuals (1982 cases and 1977 controls) collected by SLAGEN (Italian Consortium for the Genetics of ALS) together with samples from Netherlands, USA, UK, Sweden, Belgium, France, Ireland and Italy collected by ALSGEN (the International Consortium on Amyotrophic Lateral Sclerosis Genetics). We analysed a total of 13 225 individuals, 6100 cases and 7125 controls for almost 7 million single-nucleotide polymorphisms (SNPs). We identified a novel locus with genome-wide significance at 17q11.2 (rs34517613 with P = 1.11 × 10(-8); OR 0.82) that was validated when combined with genotype data from a replication cohort (P = 8.62 × 10(-9); OR 0.833) of 4656 individuals. Furthermore, we confirmed the previously reported association at 9p21.2 (rs3849943 with P = 7.69 × 10(-9); OR 1.16). Finally, we estimated the contribution of common variation to heritability of sporadic ALS as ∼12% using a linear mixed model accounting for all SNPs. Our results provide an insight into the genetic structure of sporadic ALS, confirming that common variation contributes to risk and that sufficiently powered studies can identify novel susceptibility loci.

Brain-computer interface boosts motor imagery practice during stroke recovery.

OBJECTIVE: Motor imagery (MI) is assumed to enhance poststroke motor recovery, yet its benefits are debatable. Brain-computer interfaces (BCIs) can provide instantaneous and quantitative measure of cerebral functions modulated by MI. The efficacy of BCI-monitored MI practice as add-on intervention to usual rehabilitation care was evaluated in a randomized controlled pilot study in subacute stroke patients. METHODS: Twenty-eight hospitalized subacute stroke patients with severe motor deficits were randomized into 2 intervention groups: 1-month BCI-supported MI training (BCI group, n = 14) and 1-month MI training without BCI support (control group; n = 14). Functional and neurophysiological assessments were performed before and after the interventions, including evaluation of the upper limbs by Fugl-Meyer Assessment (FMA; primary outcome measure) and analysis of oscillatory activity and connectivity at rest, based on high-density electroencephalographic (EEG) recordings. RESULTS: Better functional outcome was observed in the BCI group, including a significantly higher probability of achieving a clinically relevant increase in the FMA score (p < 0.03). Post-BCI training changes in EEG sensorimotor power spectra (ie, stronger desynchronization in the alpha and beta bands) occurred with greater involvement of the ipsilesional hemisphere in response to MI of the paralyzed trained hand. Also, FMA improvements (effectiveness of FMA) correlated with the changes (ie, post-training increase) at rest in ipsilesional intrahemispheric connectivity in the same bands (p < 0.05). INTERPRETATION: The introduction of BCI technology in assisting MI practice demonstrates the rehabilitative potential of MI, contributing to significantly better motor functional outcomes in subacute stroke patients with severe motor impairments.