Search

Background:Synaptic plasticity reserve correlates with clinical recovery after a relapse in relapsing–remitting forms of multiple sclerosis (MS) and is significantly compromised in patients with progressive forms of MS. These findings suggest that progression of disability in MS is linked to reduced synaptic plasticity reserve. D-Aspartate, an endogenous aminoacid approved for the use in humans as a dietary supplement, enhances synaptic plasticity in mice.Objective:To test whether D-Aspartate oral intake increases synaptic plasticity reserve in progressive MS patients.Methods:A total of 31 patients affected by a progressive form of MS received either single oral daily doses of D-Aspartate 2660 mg or placebo for 4 weeks. Synaptic plasticity reserve and trans-synaptic cortical excitability were measured through transcranial magnetic stimulation (TMS) protocols before and after D-Aspartate.Results:Both TMS-induced long-term potentiation (LTP), intracortical facilitation (ICF) and short-interval ICF increased after 2 and 4 weeks of D-Aspartate but not after placebo, suggesting an enhancement of synaptic plasticity reserve and increased trans-synaptic glutamatergic transmission.Conclusion:Daily oral D-Aspartate 2660 mg for 4 weeks enhances synaptic plasticity reserve in patients with progressive MS, opening the path to further studies assessing its clinical effects on disability progression.

ObjectiveTo investigate clinical and radiological outcomes of women with relapsing-remitting multiple sclerosis (RRMS) undergoing abortion.MethodsAn independent, multicentre retrospective study was conducted collecting data from eight Italian MS centres. We compared the preconception and postabortion annualised relapse rate (ARR) and number of Gadolinium enhancing (Gd+) lesions, by analyses of covariance. Variables associated with postabortion clinical and MRI activity were investigated using Poisson regression models; each abortion was considered as a statistical unit.ResultsFrom 1995 to 2017, we observed 188 abortions (17 elective) in 153 women with RRMS. Abortions occurred after a mean time of 9.5 (4.4) weeks from estimated conception date. In 86 events out of 188, conception happened during treatment with disease modifying drugs. The mean postabortion ARR (0.63±0.74) was significantly increased (p=0.037) compared with the preconception year (0.50±0.71) as well as the postabortion mean number of new Gd+ lesions (0.77±1.40 vs 0.39±1.04; p=0.004). Higher likelihood of relapses was predicted by higher preconception ARR, discontinuation of preconception treatment and elective abortion; the occurrence of new Gd+ lesions was associated with higher preconception number of active lesions, discontinuation of preconception treatment, shorter length of pregnancy maintenance and elective abortion.ConclusionsAbortion was associated with clinical and radiological inflammatory rebound remarkably in the first 12 months postevent. Deregulated proinflammatory processes arising at the early stages of pregnancy might play a role both in MS reactivation and abortion. Women with MS should be counselled about these risks of abortion and followed up accordingly.

Dimethyl fumarate (DMF) exerts anti-inflammatory effects in multiple sclerosis by activating the Nrf2 antioxidant pathway, which is also stimulated by acetylcholine via alpha-7 nicotinic acetylcholine receptors. In animal models, Nrf2 potentiates cholinergic synaptic plasticity. The aim of this study was to test whether treatment with DMF modulates cholinergic pathways in relapsing-remitting multiple sclerosis (RRMS). Patients starting DMF (20) or IFN-β 1a (20) and healthy subjects (20) were enrolled. Short-latency afferent inhibition (SAI), which is a transcranial stimulation measure of central cholinergic transmission, was recorded in patients and controls at baseline and, in patients only, after 6 months of treatment. Patients treated with DMF also underwent autonomic function testing to further explore peripheral and central cholinergic tone. At baseline, SAI was similar in patients and in controls (p = 0.983). Treatment with DMF significantly increased SAI (p = 0.01), while IFNβ had no effect (p = 0.80). In the cold face test, DMF treatment also increased reflex bradycardia (p = 0.013), and reduced diastolic blood pressure variation (p = 0.010), further indicating its ability to stimulate cholinergic transmission. Treatment of MS patients with DMF results in increased cholinergic stimulation, with possible implications for neuroinflammation and neuroprotection.

Patients with multiple sclerosis on long-term injectable therapies may suffer from the so-called “needle fatigue”, i.e., a waning commitment to continue with the prescribed injectable treatment. Therefore, alternative treatment strategies to enhance patients’ adherence are warranted. In this independent, multicentre post-marketing study, we sought to directly compare switching to either teriflunomide (TFN), dimethyl fumarate (DMF), or pegylated interferon (PEG) on treatment persistence and time to first relapse over a 12-month follow-up. We analyzed a total of 621 patients who were free of relapses and gadolinium-enhancing lesions in the year prior to switching to DMF (n = 265), TFN (n = 160), or PEG (n = 196). Time to discontinuation and time to first relapse were explored in the whole population by Cox regression models adjusted for baseline variables and after a 1:1:1 ratio propensity score (PS)-based matching procedure. Treatment discontinuation was more frequent after switching to PEG (28.6%) than DMF (14.7%; hazard ratio [HR] = 0.25, p

BackgroundNabiximols (THC/CBD Oromucosal Spray, Sativex) is used as an add-on therapy to treat moderate to severe spasticity of Multiple Sclerosis (MS).ObjectivesTo examine the impact of physiotherapy (PT) programs on effectiveness and persistence of nabiximols treatment in people with MS-related spasticity.MethodsThis is an observational multicenter study with a follow-up period of 12 weeks, conducted in routine care settings in Italy. Patients with moderate to severe MS-related spasticity who started nabiximols were included. Spasticity was evaluated by the patient-rated 0-10 numerical rating scale (NRS). Clinical data were collected at baseline (T0), 4 weeks (T1) and 12 weeks (T2) months after enrollment.ResultsA total of 297 MS patients were selected, 290 completed the 3 months follow-up period. Mean NRS scores were 7.6 ± 1.1 at T0, 5.8 ± 1.4 at T1 and 5.5 ± 1.5 at T2. At T1, 77% of patients reached ≥20% improvement (initial response, IR); 22% reached ≥30% improvement (clinically relevant response, CRR). At T1, patients undergoing PT had a higher probability to reach CRR (Odds Ratio = 2.6 95% CI 1.3-5.6, p = 0.01). Nabiximols was discontinued in 30/290 (10.3%) patients at T1 (early discontinuers) and in 71/290 (24.5%) patients at T2 (late discontinuers). The probability of being late discontinuers was reduced in patients undergoing PT (Hazard Ratio = 0.41; 95% CI 0.23-0.69, p = 0.001).ConclusionsOur real-life study confirms nabiximols' effectiveness in MS-related spasticity and suggests that the association of a PT program may improve overall response and persistence to nabiximols treatment.

Background: Fingolimod is a modulator of Central and peripheral sphingosine pathways, which is currently approved for treatment of Multiple Sclerosis (MS). In animal models it reduces inflammation, but it is also able to potentiate glutamatergic transmission and synaptic plasticity. We aimed to explore whether Fingolimod is able to modify the clinical expression of new demyelinating lesions with respect to IFNβ−1a in relapsing remitting MS (RRMS) patients suboptimal responders to IFNβ−1a. Methods: 103 patients with RRMS switching for inefficacy from IFNβ−1a to Fingolimod and treated for at least 12 months were included. Annualised Relapse Rate (ARR), EDSS and the number of new brain and spinal gadolinium enhancing (Gd +) and T2 lesions were retrospectively assessed in the whole group during each treatment period. The likelihood of co-occurrence of new Gd + lesions and clinical relapses during IFNβ−1a and Fingolimod treatment was analysed. Results: The mean duration of treatment with IFNβ−1a and Fingolimod was 3.14 (SD 1.6) and 3.22 years (SD 1.1) respectively. Significant reduction of ARR (p

Two phase III trials have demonstrated the clinical and radiological efficacy of delayed-release dimethyl fumarate (DMF) in relapsing-remitting multiple sclerosis (RRMS). However, data on its safety and effectiveness in real-world practice are still limited. The aim of our study was to explore the safety and tolerability profile of DMF in RRMS. We also tried to identify individual variables associated with better clinical and radiological outcomes. We collected the clinical and magnetic resonance imaging (MRI) data of patients with RRMS who started DMF between 2012 and 2017 in seven MS clinics in central Italy. We first evaluated DMF discontinuation rates and the incidence of adverse events and side effects. We then assessed the annualized relapse rate (ARR), the number of patients with clinical relapses or disability worsening and the presence of radiological activity. Third, we investigated which baseline variables were associated with clinical and radiological outcomes. We collected data for 1089 patients with a mean on-treatment follow-up of 17 ± 8 months; 331 (30.4%) of these patients were treatment naive. In total, 210 (19.5%) patients discontinued DMF mainly because of poor tolerability (n = 103) and disease activity (n = 63), and 166 (16.5%) patients presented with lymphopenia. The ARR reduced from 0.55 to 0.13. Mean change in Expanded Disability Status Scale (EDSS) score was 0.08 ± 0.44 per year. The occurrence of clinical and/or radiological activity during follow-up was associated with younger age [hazard ratio (HR) 0.97; p

Clinical deterioration of relapsing–remitting MS (RR-MS) patients reflects not only the number and severity of overt inflammatory and demyelinating episodes, but also subtle central damage caused by persistent exposure to inflammatory molecules. To explore the correlation between levels of CSF inflammatory molecules at the time of diagnosis and both demographic and clinical characteristics of a large sample of RR-MS patients, as well as the predictive value of cytokine levels on their prospective disease course. In 205 patients diagnosed with RR-MS, we measured at the time of diagnosis the CSF levels of inflammatory molecules. Clinical and MRI evaluation was collected at the time of CSF withdrawal and during a median follow-up of 3 years. The time interval between the first anamnestic episode of focal neurological dysfunction and RR-MS diagnosis was the main factor associated with high CSF levels of IL-6 and IL-8. Furthermore, elevated CSF levels of these cytokines correlated with enhanced risk of clinical and radiological disease reactivation, switch to second-line treatments, and with disability progression in the follow-up. Delayed diagnosis and treatment initiation are associated with higher CSF levels of IL-6 and IL-8 in RR-MS, leading to worsening disease course and poor response to treatments.

Central neuropathic pain (CNP) is common and disabling among patients with multiple sclerosis (MS). The pathological mechanisms underlying CNP in MS are not well understood. We explored whether NGF is implicated in the pathogenesis of CNP in MS. We measured NGF concentration in the CSF of 73 patients affected by MS, 15 with and 58 without CNP and 14 controls. We found increased levels of NGF in the CSF of patients with CNP compared to patients without and to controls. This finding supports the hypothesis that NGF plays a role in MS related CNP.

Background The Expanded Disability Status Scale (EDSS) is the most widely used measure of disability in MS, however because of its limitations surrogate markers of clinical disability progression are of high interest. Transcranial magnetic stimulation (TMS) measures of demyelination and cortical excitability correlate with disability levels in MS. Objective Aim of this study was testing whether paired pulse (pp) TMS represents a reliable surrogate marker to measure clinical disability in MS. Methods ppTMS measures of intracortical synaptic transmission such as short interval intracortical inhibition (SICI), long interval intracortical inhibition (LICI), short interval intracortical facilitation (SICF) and intracortical facilitation (ICF) were collected from 74 patients affected by MS. Correlation of EDSS scores with ppTMS measures was analyzed. Results EDSS scores correlated with patient’s age, disease duration, Motor Evoked Potentials latency and thresholds and SICF measures but not with age of onset, SICI, ICF and LICI. Conclusions These findings support a possible use of SICF and MEP latency as surrogate markers of disability in MS. Further research is warranted to determine the role of SICF in the follow up of disease progression and to validate its use as an endpoint in multiple sclerosis clinical trials.

Background Flu-like syndrome (FLS) is a common adverse event experienced by patients with relapsing-remitting multiple sclerosis (RRMS) treated with interferon beta (IFNβ). FLS can lead to poor treatment adherence and early IFNβ discontinuation. The involvement of interleukin-6 (IL-6) in the occurrence of FLS has been suggested. We hypothesized that cetirizine, a second-generation histamine H1 receptor antagonist able to reduce the levels of IL-6, might improve IFNβ-induced FLS. Methods We conducted a pilot, cross-over, randomized, placebo-controlled, double-blind study to evaluate the efficacy of cetirizine 10 mg added after each IFNβ injection to the standard of care for FLS (acetaminophen or nonsteroidal anti-inflammatory drugs) on FLS in patients with RRMS treated with IFNβ. Patients were randomized to two treatment sequences: 1) 4-week treatment with placebo added to the standard treatment for FLS, followed by 4-week treatment with cetirizine added to the standard of care, and 2) first addition of cetirizine, then of placebo. The primary efficacy endpoint was the mean change of FLS severity [11-point visual analog scale (VAS)] after 4 weeks of treatment within each sequence. Results Forty-five patients (71.1% female, mean age 39.1 years, mean time from RRMS diagnosis 5.8 years) were randomized to treatment sequences 1 and 2. The differences between cetirizine and placebo in the intensity of FLS were not statistically significant: total mean VAS scores at 4 hours from IFNβ injection were 3.57 and 3.42 for cetirizine and placebo, respectively (difference -0.15; 95% confidence interval: from -0.74 to 0.44; p = 0.6029). The two treatments were similar also with regard to other efficacy measures considered and to the safety/tolerability profile. Conclusions The addition of cetirizine to the standard of care for IFNβ-induced FLS in patients with RRMS does not seem to provide significant benefits compared with placebo. Further effort is required to understand the mechanisms underlying IFNβ-induced FLS. Trial registration EudraCT 2013-001055-12.

Alzheimer's disease (AD) is a neurodegenerative process characterized by progressive neuronal degeneration, reduced levels of neurotransmitters, and altered forms of synaptic plasticity. In animal models of AD, amyloid-β (Aβ) and tau proteins are supposed to interfere with synaptic transmission. In the current study, we investigated the correlation between motor cortical plasticity, measured with 1 Hz repetitive transcranial magnetic stimulation (rTMS), and the levels of Aβ₁₋₄₂, total tau (t-Tau), and phosphorylated tau (p-Tau) detected in cerebrospinal fluid (CSF) of AD patients. We found that the overall rTMS after effects were milder in AD patients in comparison with controls. In AD patients the amount of rTMS-induced inhibition correlated with CSF t-Tau, but not with Aβ₁₋₄₂ CSF levels. Surprisingly, higher CSF t-Tau levels were associated to a stronger inhibition of the motor evoked potentials, implying that the expected effects of the 1 Hz rTMS protocol were more evident in patients with more pathological t-Tau CSF levels. These data could be interpreted as the consequence of CSF t-Tau mediated abnormal excitatory activity and could suggest that CSF t-Tau may impact mechanisms of cortical plasticity.

Neuropathic pain in patients with MS is frequent and is associated with a great interference with daily life activities. In the present study, we investigated whether anodal transcranial direct current stimulation (tDCS) may be effective in reducing central chronic pain in MS patients. Patients received sham tDCS or real tDCS in a 5-day period of treatment in a randomized, double blind, sham-controlled study. Pain was measured using visual analog scale (VAS) for pain and the short form McGill questionnaire (SF-MPQ). Quality of life was measured using the Multiple Sclerosis Quality of Life-54 scale (MSQoL-54). Depressive symptoms and anxiety were also evaluated as confounding factors using the Beck Depression Inventory (BDI) and VAS for anxiety. Evaluations were performed at baseline, immediately after the end of treatment, and once a week during a 3-week follow-up period. Following anodal but not sham tDCS over the motor cortex, there was a significant pain improvement as assessed by VAS for pain and McGill questionnaire, and of overall quality of life. No depression or anxiety changes were observed. Our results show that anodal tDCS is able to reduce pain-scale scores in MS patients with central chronic pain and that this effect outlasts the period of stimulation, leading to long-lasting clinical effects. Perspective This article presents a new, noninvasive therapeutic approach to chronic, central neuropathic pain in multiple sclerosis, poorly responsive to current conventional medications. tDCS is known to cause long-lasting changes of neuronal excitability at the site of stimulation and in the connected areas in healthy subjects. This led us to hypothesize that pain decrease may be the result of functional plastic changes in brain structures involved in the pathogenesis of chronic neuropathic pain.

Background and purpose: Spasticity is a common disorder and a major cause of long-term disability in patients with multiple sclerosis (MS). Our aim was to evaluate whether a recently developed repetitive transcranial magnetic stimulation protocol, the intermittent theta burst stimulation (iTBS) is effective in modulating lower limb spasticity in MS patients. Methods: Twenty MS patients were pseudorandomized to undergo a 2-week daily sessions of real or sham iTBS protocol. The H/M amplitude ratio of the Soleus H reflex, a reliable neurophysiological index of spinal excitability and the Modified Ashworth Scale (MAS) for spasticity were evaluated by blinded raters before and after the stimulation protocols. Results: Patients receiving real iTBS showed a significant reduction of H/M amplitude ratio and MAS scores 1 week after the stimulation and persisting up to 2 weeks after the end of stimulation protocol. There were no significant effects for sham stimulation. Conclusions: These results show that iTBS, a safe, non-invasive, well-tolerated and feasible protocol, is a promising tool for the treatment of spasticity in MS.

Summary Aim Natalizumab (NTZ) discontinuation leads to multiple sclerosis (MS) recurrence, but represents the only known strategy to limit the risk of progressive multifocal leukoencephalopathy (PML) in JCV seropositive patients. Here, we compared the clinical and imaging features of three groups of patients who discontinued NTZ treatment. Methods We treated 25 patients with subcutaneous INFβ-1b (INF group), 40 patients with glatiramer acetate (GA group), and 40 patients with GA plus pulse steroid (GA+CS group). Results Six of 25 patients (24%) of the INF group were relapse-free 6 months after NTZ suspension. In GA group, a significant higher proportion of patients (26 of 40 patients, 65%) were relapse-free (P

Background: In multiple sclerosis (MS), the location of focal lesions does not always correlate with clinical symptoms, suggesting disconnection as a major pathophysiological mechanism. Resting-state (RS) functional magnetic resonance imaging (fMRI) is believed to reflect brain functional connectivity (FC) within specific neuronal networks. Objective: RS-fMRI was used to investigate changes in FC within two critical networks for the understanding of MS disabilities, namely, the sensory-motor network (SMN) and the default-mode network (DMN), respectively, implicated in sensory-motor and cognitive functions. Methods: Thirty-four relapsing–remitting (RR), 14 secondary progressive (SP) MS patients and 25 healthy controls underwent MRI at 3T, including conventional images, T1-weighted volumes, and RS-fMRI sequences. Independent component analysis (ICA) was employed to extract maps of the relevant RS networks for every participant. Group analyses were performed to assess changes in FC within the SMN and DMN in the two MS phenotypes. Results: Increased FC was found in both networks of MS patients. Interestingly, specific changes in either direction were observed also between RR and SP MS groups. Conclusions: FC changes seem to parallel patients’ clinical state and capability of compensating for the severity of clinical/cognitive disabilities.

Synaptic transmission and plasticity mediated by NMDA receptors (NMDARs) could modulate the severity of multiple sclerosis (MS). Here the role of NMDARs in MS was first explored in 691 subjects carrying specific allelic variants of the NR1 subunit gene or of the NR2B subunit gene of this glutamate receptor. The analysis was replicated for significant SNPs in an independent sample of 1548 MS subjects. The C allele of rs4880213 was found to be associated with reduced NMDAR-mediated cortical excitability, and with increased probability of having more disability than the CT/TT MS subjects. MS severity was higher in the CC group among relapsing-remitting MS (RR-MS) patients, while primary progressive MS (PP-MS) subjects homozygous for the T allele had more pronounced clinical worsening. Mean time to first relapse, but not to an active MRI scan, was lower in the CC group of RR-MS patients, and the number of subjects with two or more clinical relapses in the first two years of the disease was higher in CC compared to CT/TT group. Furthermore, the percentage of relapses associated with residual disability was lower in subjects carrying the T allele. Lesion load at the MRI was conversely unaffected by the C or T allele of this SNP in RR-MS patients. Axonal and neuronal degeneration at the optical coherence tomography was more severe in the TT group of PP-MS patients, while reduced retinal nerve fiber thickness had less consequences on visual acuity in RR-MS patients bearing the T allele. Finally, the T allele was associated with preserved cognitive abilities at the Rao's brief repeatable neuropsychological battery in RR-MS. Signaling through glutamate NMDARs enhances both compensatory synaptic plasticity and excitotoxic neurodegeneration, impacting in opposite ways on RR-MS and PP-MS pathophysiological mechanisms.

Background and purpose Multiple sclerosis (MS) patients discontinuing natalizumab are at risk of rebound of disease activity. Methods In the present multi-center, open-label, non-randomized, prospective, pilot study, we tested whether treatment with glatiramer acetate (GA) is safe and effective after natalizumab in MS patients. The study was performed at academic tertiary medical centers. Forty active relapsing–remitting MS patients who never failed GA therapy and who discontinued natalizumab after 12–18 months of therapy were enrolled. GA was initiated 4 weeks after the last dose of natalizumab. Results 62.5% of patients were relapse-free 12 months after GA initiation. Annualized relapse rate and time to relapse were significantly lower than before natalizumab. Notably, the frequency of relapses was significantly lower amongst those patients who had experienced ≤2 relapses the year before initiation of natalizumab therapy, compared with patients who had had three or more relapses. No evidence of rebound was observed in magnetic resonance imaging scans. Furthermore, Expanded Disability Status Scale and Multiple Sclerosis Functional Composite were stable in our patients, again suggesting that 12 months of post-natalizumab–GA therapy is not associated with clinical deterioration. Conclusions Following discontinuation of natalizumab, 12 months of therapy with GA is safe and well tolerated in MS patients. GA can reduce the risk of early reactivation/rebound of disease activity in this setting.

Background: Multiple sclerosis (MS) patients discontinuing natalizumab treatment are at risk of disease reactivation. No clinical or surrogate parameters exist to identify patients at risk of post-natalizumab MS reactivation. Objective: To determine the role of natalizumab-induced lymphocytosis and of Akt polymorphisms in disease reactivation after natalizumab discontinuation. Methods: Peripheral leukocyte count and composition were monitored in 93 MS patients during natalizumab treatment, and in 56 of these subjects who discontinued the treatment. Genetic variants of the anti-apoptotic protein Akt were determined in all subjects because natalizumab modulates the apoptotic pathway and lymphocyte survival is regulated by the apoptotic cascade. Results: Natalizumab-induced peripheral lymphocytosis protected from post-natalizumab MS reactivation. Subjects who relapsed or had magnetic resonance imaging (MRI) worsening after treatment cessation, in fact, had milder peripheral lymphocyte increases during the treatment, largely caused by less marked T cell increase. Furthermore, subjects carrying a variant of the gene coding for Akt associated with reduced anti-apoptotic efficiency (rs2498804T) had lower lymphocytosis and higher risk of disease reactivation. Conclusion: This study identified one functionally meaningful genetic variant within the Akt signaling pathway that is associated with both lymphocyte count and composition alterations during natalizumab treatment, and with the risk of disease reactivation after natalizumab discontinuation.

Studies in rodents show that transient receptor potential vanilloid 1 (TRPV1) channels regulate glutamate release at central and peripheral synapses. In humans, a number of nonsynonymous single-nucleotide polymorphisms (SNPs) have been described in theTRPV1gene, and some of them significantly alter the functionality of the channel. To address the possible role of TRPV1 channels in the regulation of synaptic transmission in humans, we studied how TRPV1 genetic polymorphisms affect cortical excitability measured with transcranial magnetic stimulation (TMS). Two SNPs of theTRPV1gene were selected and genotyped (rs222747 and rs222749) in a sample of 77 healthy subjects. In previous cell expression studies, the “G” allele of rs222747 was found to enhance the activity of the channel, whereas rs222749 had no functional effect. Allelic variants in the rs222749 region were not associated with altered cortical response to single, paired, and repetitive TMS. In contrast, subjects homozygous for the G allele in rs222747 exhibited larger short-interval intracortical facilitation (a measure of glutamate transmission) explored through paired-pulse TMS of the primary motor cortex. Recruitment curves, short-interval intracortical inhibition, intracortical facilitation, and long-interval intracortical inhibition were unchanged. LTP- and LTD-like plasticity explored through intermittent or continuous theta-burst stimulation was also similar in the “G” and “non-G” subjects. To our knowledge, our results provide the first evidence that TRPV1 channels regulate cortical excitability to paired-pulse stimulation in humans.

Background Cerebellar repetitive transcranial magnetic stimulation may be effective in reducing peak-dose levodopa induced dyskinesia in Parkinson’s disease patients. It was proposed that the antidyskinetic effect could be due to modulation of cerebello-thalamo-cortical pathways. However the neural basis for these clinical effects have not yet been demonstrated. Methods We investigated the effects of repeated sessions of cerebellar continuous theta burst stimulation in Parkinson’s disease patients with levodopa induced dyskinesia on brain metabolism by means of positron emission tomography scan with fluorodeoxyglucose (18F-FDG) to characterize the specific cerebral network activated by cerebellar stimulation in these patients. Results We found that five days of bilateral cerebellar continuous theta burst stimulation (cTBS) were effective in reducing levodopa induced dyskinesia. Clinical changes were paralleled by a reduction of 18F-FDG metabolism in the cerebellum as revealed by positron emission tomography imaging. We found a global decrease in the metabolism of the bilateral cerebellar hemispheres, and a significant decrease in 18F-FDG uptake in correspondence of bilateral dentate nucleus. Conclusions Our study demonstrates the antidyskinetic effect of cerebellar cTBS in Parkinson’s disease patients with levodopa induced dyskinesia, is paralleled by modulation of the activity of the pathways connecting the cerebellar cortex with the deep cerebellar nuclei, confirming the hypothesis that the motor cerebellar circuit is involved in the generations of levodopa induced dyskinesia.

Acute inflammation is associated with cognitive deficits and alterations of cortical plasticity in multiple sclerosis (MS). We tested whether early treatment with high-dose interferon (IFN) beta-1a, known to reduce inflammatory activity, improves cortical function and cognitive deficits in MS. Eighty treatment-naïve relapsing-remitting MS (RRMS)patients received IFN beta-1a (44 mcg) subcutaneously three times per week. Cognitive performance and cortical plasticity were measured through the paced auditory serial addition test (PASAT) and intermittent theta burst stimulation (iTBS) before and up to two years af-ter IFN beta-1a initiation. Before treatment, patients with gadolinium-enhancing lesions (Gd+) on MRI performed worse on the PASAT,and showed lower iTBS-induced plasticity, compared with Gd- patients. Six months after treatment initiation both PASAT and iTBS-induced plasticity improved in Gd+ and remained stable in Gd- patients. These results suggest that cognitive and synaptic plasticity deficits may be rescued during high-doseIFN beta-1a treatment in newly-diagnosed RRMS patients with Gd+ lesions.

Objectives: To investigate the inter-hemispheric connections between the dorsal premotor cortex (dPM) and contralateral primary motor cortex (M1) in schizophrenia. Methods: Sixteen medicated, nine unmedicated schizophrenia patients and 20 healthy age-matched subjects were studied by twin-coil Transcranial Magnetic Stimulation. To activate distinct facilitatory and inhibitory transcallosal pathways between dPM and the contralateral M1, the intensity of dPM stimulation was adjusted to be either suprathreshold (110% of resting motor threshold) or subthreshold (80% of active motor threshold). Interstimulus intervals between conditioning stimulus and test stimulus were 6, 8 and 15 ms. Results: Schizophrenia patients had comparable efficacy of the inhibitory pathway. On the other hand, medicated patients showed less facilitation of contralateral M1 following dPM stimulation at 80% of active motor threshold, at interstimulus interval = 8 ms. The individual amount of facilitation induced by dPM conditioning at 80% of active motor threshold at interstimulus interval = 8 ms correlated negatively with negative symptoms. Conclusions: Inter-hemispheric facilitatory dPM–M1 connectivity is selectively altered in schizophrenia. Significance: This study produced evidence that dPM–M1 connectivity is dysfunctional and that correlates with negative symptoms. These results converge with previous studies which strongly hypothesize that inter- and intra-hemispheric connectivity disturbances may play a major role in schizophrenia.

Cognitive dysfunction is of frequent observation in multiple sclerosis (MS). It is associated with gray matter pathology, brain atrophy, and altered connectivity, and recent evidence showed that acute inflammation can exacerbate mental deficits independently of the primary functional system involved. In this study, we measured cerebrospinal fluid (CSF) levels of amyloid-β(1-42) and τ protein in MS and in clinically isolated syndrome patients, as both proteins have been associated with cognitive decline in Alzheimer's disease (AD). In AD, amyloid-β(1-42) accumulates in the brain as insoluble extracellular plaques, possibly explaining why soluble amyloid-β(1-42) is reduced in the CSF of these patients. In our sample of MS patients, amyloid-β(1-42) levels were significantly lower in patients cognitively impaired (CI) and were inversely correlated with the number of Gadolinium-enhancing (Gd+) lesions at the magnetic resonance imaging (MRI). Positive correlations between amyloid-β(1-42) levels and measures of attention and concentration were also found. Furthermore, abnormal neuroplasticity of the cerebral cortex, explored with θ burst stimulation (TBS), was observed in CI patients, and a positive correlation was found between amyloid-β(1-42) CSF contents and the magnitude of long-term potentiation-like effects induced by TBS. No correlation was conversely found between τ protein concentrations and MRI findings, cognitive parameters, and TBS effects in these patients. Together, our results indicate that in MS, central inflammation is able to alter amyloid-β metabolism by reducing its concentration in the CSF and leading to impairment of synaptic plasticity and cognitive function.

Exercise therapy (ET) can be beneficial in disabled multiple sclerosis (MS) patients. Intermittent transcranial magnetic theta burst stimulation (iTBS) induces long-term excitability changes of the cerebral cortex and may ameliorate spasticity in MS. We investigated whether the combination of iTBS and a program of ET can improve motor disability in MS patients. In a double-blind, sham-controlled trial, 30 participants were randomized to three different interventions: iTBS plus ET, sham stimulation plus ET, and iTBS alone. Before and after 2 weeks of treatment, measures of spasticity through the modified Ashworth scale (MAS) and the 88 items Multiple Sclerosis Spasticity Score questionnaire (MSSS-88), fatigue through the Fatigue Severity Scale (FSS), daily living activities (ADL) through the Barthel index and health-related quality of life (HRQoL) through the 54 items Multiple Sclerosis Quality of life inventory (MSQoL-54) were collected. iTBS plus ET reduced MAS, MSSS-88, FSS scores, while in the Barthel index and MSQoL-54, physical composite scores were increased. iTBS alone caused a reduction of the MAS score, while none of the measured scales showed significant changes after sham iTBS plus ET. iTBS associated with ET is a promising tool for motor rehabilitation of MS patients.

Objective Mechanisms of synaptic plasticity like long term depression (LTD) are altered in experimental models of Alzheimer’s disease (AD). LTD-like plasticity mechanisms has not been yet fully investigated in AD patients. Methods Here we studied the effects of low frequency (1 Hz) repetitive transcranial magnetic stimulation (rTMS) over the primary motor cortex in a group of patients with a diagnosis of probable AD, compared to healthy age-matched controls (HS). Moreover, we tested the effects of a single dose of orally administered L-dopa, one of the key neurotransmitters in modulating synaptic plasticity mechanisms, on rTMS induced plasticity. Results We found that in AD patients the 1 Hz rTMS protocol did not induce the expected inhibitory effect, while a long lasting inhibition of MEP was observed in HS. In addition, L-dopa induced a clear form of reversal of the direction of plasticity in HS that was not evident in AD. Conclusions Dopamine modulation of LTD-like plasticity is impaired when tested in AD patients. Significance These findings provide evidence of possible dysfunction of dopaminergic transmission in AD patients.

Background: Patients with multiple sclerosis may present altered patterns of connectivity between the two brain hemispheres. To date, only transcallosal connectivity between the two primary motor cortices (M1) has been investigated functionally in patients with multiple sclerosis. Objectives: The aim of this study was to investigate whether connectivity between the dorsal premotor cortex and the contralateral M1 was altered in patients with multiple sclerosis, and to see whether clinical progression is accompanied by exacerbated dorsal premotor cortex—M1 disconnectivity. Methods: A twin-coil transcranial magnetic stimulation approach was used to investigate both excitatory and inhibitory interhemispheric connections between the left dorsal premotor cortex and the contralateral M1 in 18 multiple sclerosis patients without disability, in 18 multiple sclerosis patients with advanced disease and in 12 age-matched healthy subjects. To activate distinct inhibitory and facilitatory transcallosal pathways, the intensity of dorsal premotor cortex stimulation was adjusted to be either suprathreshold (110% of resting motor threshold) or subthreshold (80% of active motor threshold). Results: Our sample of patients with multiple sclerosis showed altered patterns of interhemispheric dorsal premotor cortex—M1 functional connectivity even in the absence of clinical deficits. Facilitatory connections originating from dorsal premotor cortex were reduced in multiple sclerosis patients with or without disability, while inhibitory dorsal premotor cortex—M1 connections were altered only in disabled patients. Conclusions: The current study demonstrates that functional excitatory connectivity originating from non-primary motor areas is compromised in multiple sclerosis patients even in the absence of clinical disability. Clinical disease progression leads to an impairment of both excitatory and inhibitory transcallosal connections.

Background In animal models, the cannabinoid system has been convincingly implicated in the regulation of long-lasting synaptic plasticity. Both long-term potentiation (LTP) and depression (LTD) phenomena can be induced in the human motor cortex by transcranial magnetic theta burst stimulation (TBS). Objective/Hypothesis Here, we explored the potential involvement of the cannabinoid system in TBS-induced synaptic plasticity in humans. Methods We tested the effects of a cannabis-based preparation (Sativex) on continuous TBS (cTBS) and intermittent TBS (iTBS) protocols in subjects with multiple sclerosis. Results We observed a shift in the polarity of synaptic plasticity induced by cTBS. In these subjects, in fact, cTBS induced the expected inhibition of motor-evoked potentials (MEPs) before Sativex exposure, whereas it caused a persisting enhancement of MEP amplitude 4 weeks after. The LTP-like phenomenon induced by iTBS was conversely unaffected by Sativex. Conclusions Our results indicate that cannabis ingredients have metaplastic effects on the motor cortex, and strongly suggest that the cannabinoid system is involved in the modulation of synaptic plasticity not only in rodents but also in humans.

In Alzheimer's disease (AD) patients dysfunction of cholinergic neurons is considered a typical hallmark, leading to a rationale for the pharmacological treatment in use based on drugs that enhance acetylcholine neurotransmission. However, besides altered acetylcholine transmission, other neurotransmitter systems are involved in cognitive dysfunction leading to dementia. Among others, dopamine seems to be particularly involved in the regulation of cognitive processes, also having functional relationship with acetylcholine. To test whether cholinergic dysfunction can be modified by dopamine, we used short latency afferent inhibition (SLAI) as a neurophysiological tool. First, we tested the function of the cholinergic system in AD patients and in healthy subjects. Then, we tested whether a single L-dopa challenge was able to interfere with this system in both groups. We observed that SLAI was reduced in AD patients, and preserved in normal subjects. L-dopa administration was able to restore SLAI modification only in AD, having no effect in healthy subjects. We conclude that dopamine can modify SLAI in AD, thus confirming the relationship between acetylcholine and dopamine systems. Moreover, it is suggested that together with cholinergic, dopaminergic system alteration is likely to occur in AD, also. These alterations might be responsible, at least in part, for the progressive cognitive decline observed in AD patients.

We tested the effects of 5-Hz repetitive transcranial magnetic stimulation (rTMS) over the motor cortex in multiple sclerosis (MS) subjects with cerebellar symptoms. rTMS improved hand dexterity in cerebellar patients ( n = 8) but not in healthy subjects ( n = 7), as detected by a significant transient reduction of the time required to complete the nine-hole pegboard task. rTMS of the motor cortex may be a useful approach to treat cerebellar impairment in MS patients.