Muscle atonia index during multiple sleep latency test: A possible marker to differentiate narcolepsy from other hypersomnias

OBJECTIVE

The complexity and delay of the diagnosis of narcolepsy require several diagnostic tests and invasive procedures such as lumbar puncture. Our study aimed to determine the changes in muscle tone (atonia index, AI) at different levels of vigilance during the entire multiple sleep latency test (MSLT) and each nap in people with narcolepsy type 1 (NT1) and 2 (NT2) compared with other hypersomnias and its potential diagnostic value.

METHODS

Twenty-nine patients with NT1 (11 M 18F, mean age 34.9 years, SD 16.8) and sixteen with NT2 (10 M 6F, mean age 39 years, SD 11.8) and 20 controls with other hypersomnias (10 M, 10F mean age 45.1 years, SD 15.1) were recruited. AI was evaluated at different levels of vigilance (Wake and REM sleep) in each nap and throughout the MSLT of each group. The validity of AI in identifying patients with narcolepsy (NT1 and NT2) was analyzed using receiver operating characteristic (ROC) curves.

RESULTS

AI during wakefulness (WAI) was significantly higher in the narcolepsy groups (NT1 and NT2 p < 0.001) compared to the hypersomniac group. AI during REM sleep (RAI) (p = 0.03) and WAI in nap with sudden onsets of REM sleep periods (SOREMP) (p = 0.001) were lower in NT1 than in NT2. The ROC curves showed high AUC values for WAI (NT1 0.88; Best Cut-off > 0.57, Sensitivity 79.3 % Specificity 90 %; NT2 0.89 Best Cut-off > 0.67 Sensitivity 87.5 % Specificity 95 %; NT1 and NT2 0.88 Best Cut-off > 0.57 Sensitivity 82.2 % Specificity 90 %) in discriminating subjects suffering from other hypersomnias. RAI and WAI in nap with SOREMP showed a poor AUC value (RAI AUC: 0.7 Best cutoff 0.7 Sensitivity 50 % Specificity 87.5 %; WAI in nap before SOREMP AUC: 0.66, Best cut-off < 0.82 sensitivity 61.9 % and specificity 67.35 %) differentiating NT1 and NT2.

CONCLUSIONS

WAI may represent an encouraging electrophysiological marker of narcolepsy and suggests a vulnerable tendency to dissociative wake / sleep dysregulation lacking in other forms of hypersomnia.

SIGNIFICANCE

AI during wakefulness may help distinguish between narcolepsy and other hypersomnias.

Identifying neuropathic pain in patients with multiple sclerosis: a cross-sectional multicenter study using highly specific criteria

BACKGROUND

Pain is a common and heterogeneous complication of multiple sclerosis (MS). In this multicenter, cross sectional study, we aimed at investigating the prevalence of pain in MS using highly specific criteria for distinguishing the different types of pain.

MATERIALS AND METHODS

After a structured interview, in patients with pain, clinical examination and DN4 questionnaire were used for distinguishing neuropathic and nociceptive pain. In subjects with neuropathic pain, the Neuropathic Pain Symptom Inventory was used for differentiating neuropathic pain symptoms.

RESULTS

We enrolled 1249 participants (832 F, 417 M, mean age 33.9 years, mean disease duration 8 years, mean EDSS 3.2); based on clinical evaluation and DN4 score 429 patients (34.34%) were classified with pain (470 pain syndromes): 286 nociceptive pain syndromes and 184 neuropathic pain syndromes. Multivariate analysis showed that pain was associated with age, gender and disease severity and that neuropathic pain was distinctly associated with EDSS.

CONCLUSIONS

Our study, providing definite information on the prevalence, characteristics and variables associated with neuropathic pain due to MS, shows that a more severe disease course is associated with a higher risk of neuropathic pain. Our findings might, therefore, provide a basis for improving the clinical management of this common MS complication.

A novel crosstalk within the endocannabinoid system controls GABA transmission in the striatum

The N-palmitoylethanolamine (PEA) is an endogenous member of the endocannabinoid system (ECS) with several biological functions, including a neuromodulatory activity in the central nervous system. To shed light on the neuronal function of PEA, we investigated its involvement in the control of both excitatory and inhibitory transmission in the murine striatum, a brain region strongly modulated by the ECS. By means of electrophysiological recordings, we showed that PEA modulates inhibitory synaptic transmission, through activation of GPR55 receptors, promoting a transient increase of GABAergic spontaneous inhibitory postsynaptic current (sIPSC) frequency. The subsequently rundown effect on sIPSC frequency was secondary to the delayed stimulation of presynaptic cannabinoid CB1 receptors (CB1Rs) by the endocannabinoid 2-AG, whose synthesis was stimulated by PEA on postsynaptic neurons. Our results indicate that PEA, acting on GPR55, enhances GABA transmission in the striatum, and triggers a parallel synthesis of 2-AG at the postsynaptic site, that in turn acts in a retrograde manner to inhibit GABA release through the stimulation of presynaptic CB1Rs. This electrophysiological study identifies a previously unrecognized function of PEA and of GPR55, demonstrating that GABAergic transmission is under the control of this compound and revealing that PEA modulates the release of the endocannabinoid 2-AG.

Effects of motor cortex rTMS on lower urinary tract dysfunction in multiple sclerosis

We tested the effects of 5-Hz rTMS over the motor cortex in multiple sclerosis (MS) subjects complaining of lower urinary tract symptoms either in the filling or voiding phase. Our data show that motor cortex stimulation for five consecutive days over two weeks ameliorates the voiding phase of the micturition cycle, suggesting that enhancing corticospinal tract excitability might be useful to ameliorate detrusor contraction and/or urethral sphincter relaxation in MS patients with bladder dysfunction. Multiple Sclerosis 2007; 13: 269–271. http://msj.sagepub.com

Depressive Symptoms Correlate with Disability and Disease Course in Multiple Sclerosis Patients: An Italian Multi-Center Study Using the Beck Depression Inventory

Background

Depression occurs in about 50% of patients with multiple sclerosis. The aims of this study was to investigate the prevalence of depressive symptoms in a multicenter MS population using the Beck Depression Inventory II (BDI II) and to identify possible correlations between the BDI II score and demographic and clinical variables.

Methods

Data were collected in a multi-center, cross-sectional study over a period of six months in six MS centers in Italy using BDI II.

Results

1,011 MS patients participated in the study. 676 subjects were female, with a mean age of 34 years (SD 10.8), mean EDSS of 3.3 (0–8.5) and mean disease duration of 10.3 years (range 1–50 years). 668 (%) subjects scored lower than 14 on the BDI II and 343 (33.9%) scored greater than 14 (14 cut-off score). For patients with BDI>14 multivariate analysis showed a significant difference between EDSS and disease course. BDI II scores for subjects with secondary progressive (SP) MS were significantly different from primary progressive (PP) patients (p < 0.001) but similar to relapsing-remitting (RR) patients. Considering subjects with moderate to severe depressive symptoms (BDI II score from 20–63), in relation to disease course, 11.7% (83/710) had RR MS, 40.7% (96/236) SP and 13.6% (6/44) PP.

Conclusions

Using the BDI II, 30% of the current sample had depressive symptoms. BDI II score correlates with disability and disease course, particularly in subjects with SP MS. The BDI II scale can be a useful tool in clinical practice to screen depressive symptoms in people with MS.

Efficacy and safety of cannabinoid oromucosal spray for multiple sclerosis spasticity

BACKGROUND

The approval of 9-δ-tetrahydocannabinol and cannabidiol (THC:CBD) oromucosal spray (Sativex) for the management of treatment-resistant multiple sclerosis (MS) spasticity opened a new opportunity for many patients. The aim of our study was to describe Sativex effectiveness and adverse events profile in a large population of Italian patients with MS in the daily practice setting.

METHODS

We collected data of all patients starting Sativex between January 2014 and February 2015 from the mandatory Italian medicines agency (AIFA) e-registry. Spasticity assessment by the 0-10 numerical rating scale (NRS) scale is available at baseline, after 1 month of treatment (trial period), and at 3 and 6 months.

RESULTS

A total of 1615 patients were recruited from 30 MS centres across Italy. After one treatment month (trial period), we found 70.5% of patients reaching a ≥20% improvement (initial response, IR) and 28.2% who had already reached a ≥30% improvement (clinically relevant response, CRR), with a mean NRS score reduction of 22.6% (from 7.5 to 5.8). After a multivariate analysis, we found an increased probability to reach IR at the first month among patients with primary and secondary progressive MS, (n=1169, OR 1.4 95% CI 1.04 to 1.9, p=0.025) and among patients with >8 NRS score at baseline (OR 1.8 95% CI 1.3-2.4 p<0.001). During the 6 months observation period, 631(39.5%) patients discontinued treatment. The main reasons for discontinuation were lack of effectiveness (n=375, 26.2%) and/or adverse events (n=268, 18.7%).

CONCLUSIONS

Sativex can be a useful and safe option for patients with MS with moderate to severe spasticity resistant to common antispastic drugs.

Rituximab in the treatment of Neuromyelitis optica: a multicentre Italian observational study

Rituximab (RTX) efficacy in NMO is suggested by several case series. No consensus exists on optimal dosing strategies. At present the treatment schedules more frequently used are 375 mg/m2/week iv for 4 weeks (RTX-A) and 1000 mg iv twice, 2 weeks apart (RTX-B). Aim of this study is to confirm RTX efficacy and safety in the treatment of NMO and to evaluate whether a most favourable dosage regimen exists. Data on RTX-treated NMO patients were collected from 13 Italian Hospitals. 73 patients (64 F), were enlisted. RTX-A was administered in 42/73 patients, RTX-B in 31/73. Median follow-up was 27 months (range 7-106). Mean relapse rate in the previous year before RTX start was 2.2 ± 1.3 for RTX-A and 2.3 ± 1.2 for RTX-B. ARR in the first year of treatment was 0.8 ± 0.9 for RTX-A and 0.2 ± 0.4 for RTX-B, in the second year of treatment was 0.9 ± 1.5 for RTX-A and 0.4 ± 0.8 for RTX-B patients (p = 0.001 for the first year, ns (0.09) for the second year). RTX-B was more effective in delaying the occurrence of a relapse (HR 2.2 (95 % IC 1.08-4.53) p = 0.02). Adverse events were described in 19/73 patients (mainly urinary tract and respiratory infections, and infusion reactions). Two deaths were reported in severely disabled patients. Though with the limitations of an observational study, our data support RTX efficacy in NMO and suggest that high dose pulses might be more effective than a more fractioned dose.

Epigenetic modifications of Dexras 1 along the nNOS pathway in an animal model of multiple sclerosis

The development of multiple sclerosis, a major neurodegenerative disease, is due to both genetic and environmental factors that might trigger aberrant epigenetic changes of the genome. In this study, we analysed global DNA methylation in the brain of mice upon induction of experimental autoimmune encephalomyelitis (EAE), and the effect of environmental enrichment (EE). We demonstrate that global DNA methylation decreased in the striatum, but not in the cortex, of EAE mice compared to healthy controls, in particular in neuronal nitric oxide synthase (nNOS)-positive interneurons of this brain area. Also, in the striatum but again not in the cortex, decreased DNA methylation of the nNOS downstream effector, dexamethasone-induced Ras protein 1 (Dexras 1), was observed in EAE mice, and was paralleled by an increase in its mRNA. Interestingly, EE was able to revert EAE effects on mRNA expression and DNA methylation levels of Dexras 1 and reduced gene expression of nNOS and 5-lipoxygenase (Alox5). Conversely, interleukin-1β (IL-1β) gene expression was found up-regulated in EAE mice compared to controls and was not affected by EE. Taken together, these data demonstrate an unprecedented epigenetic modulation of nNOS-signaling in the pathogenesis of multiple sclerosis, and show that EE can specifically revert EAE effects on Dexras 1 along this pathway.

Diagnostic tools for assessment of urinary dysfunction in MS patients without urinary disturbances

Many guidelines are available for the management of lower urinary tract symptoms (LUTSs) in multiple sclerosis (MS) patients, but no agreement exists on the best approach for subjects without LUTSs. The objective of this study was to evaluate whether LUTSs can be detected in MS patients asymptomatic for urinary dysfunction, comparing three different tools [measure of post-void residual volume (PRV), bladder diary (BD), a focused questionnaire (IPSS)], and whether disability, disease duration and signs of pyramidal involvement are linked to their subclinical presence. 178 MS patients (118 women) have been included (mean age 41.2 years, mean disease duration 11.3 years, mean EDSS 2.2), and tested with the above-mentioned tools. PRV was abnormal in 14 subjects (7.8%), associated to abnormal findings at IPSS in 3 cases, at BD in 2 cases, at both in 1. BD was abnormal in 37 subjects (20.8%), with concomitant abnormal PRV in 2, abnormal IPSS in 10 cases, abnormal IPSS and BD in 1. IPSS was ≥ 9 in 43 subjects (24.1%). At least one test was abnormal in 76 patients (42.7%): 1 in 57 patients (32.0%), 2 in 17 (9.5%), and 3 tests in 2 (1.1%). Patients with at least one abnormal urinary variable, compared to patients without urinary abnormalities, had a more frequent pyramidal involvement (69.5 vs. 16.8%, χ(2) = 48.6, p < 0.00001), a more frequent occurrence of EDSS ≥2 (83.1 vs. 23.5%, χ(2) = 56.9, p < 0.00001), and a longer disease duration (15.7 ± 7.3 vs. 9.1 ± 7.1, t = 5.7, p < 0.00001). Asymptomatic LUTS were frequent but none of the tests used permitted to better identify asymptomatic patients.

FAS-ligand regulates differential activation-induced cell death of human T-helper 1 and 17 cells in healthy donors and multiple sclerosis patients

Functionally distinct T-helper (Th) subsets orchestrate immune responses. Maintenance of homeostasis through the tight control of inflammatory Th cells is crucial to avoid autoimmune inflammation. Activation-Induced Cell Death (AICD) regulates homeostasis of T cells, and it has never been investigated in human Th cells. We generated stable clones of inflammatory Th subsets involved in autoimmune diseases, such as Th1, Th17 and Th1/17 cells, from healthy donors (HD) and multiple sclerosis (MS) patients and we measured AICD. We find that human Th1 cells are sensitive, whereas Th17 and Th1/17 are resistant, to AICD. In particular, Th1 cells express high level of FAS-ligand (FASL), which interacts with FAS and leads to caspases' cleavage and ultimately to cell death. In contrast, low FASL expression in Th17 and Th1/17 cells blunts caspase 8 activation and thus reduces cell death. Interestingly, Th cells obtained from healthy individuals and MS patients behave similarly, suggesting that this mechanism could explain the persistence of inflammatory IL-17-producing cells in autoimmune diseases, such as MS, where their generation is particularly substantial.

Subclinical central inflammation is risk for RIS and CIS conversion to MS

Background:

Subtle diffuse intrathecal inflammation is undetectable by conventional neuroimaging, and could influence multiple sclerosis (MS) disease course.

Objective:

To explore the role of subclinical persisting intrathecal inflammation in radiologically isolated syndrome (RIS) or clinically isolated syndrome (CIS) conversion to MS, and in early MS disease reactivation.

Methods:

One-hundred ninety-three subjects with RIS, CIS, relapsing–remitting (RR), or primary progressive (PP) MS were included, along with 76 matched controls. Cerebrospinal fluid (CSF) levels of interleukin-8 (IL-8), a major proinflammatory cytokine, were measured as a biomarker of intrathecal inflammation. Patients were followed up for 2 years. Clinical and imaging measures of disease progression were recorded.

Results:

High central contents of IL-8 were associated to clinical progression in subjects with RIS, and to the risk of conversion to MS in subjects with CIS. Asymptomatic intrathecal inflammation placed subjects at risk for MS conversion, even regardless lesion load. CSF IL-8 levels were higher in RR MS with high disease activity. Higher number of relapses in the first two years since diagnosis and shorter first inter-attack intervals were observed in patients with high levels of IL-8.

Conclusion:

IL-8 might provide utility in determining the presence of active intrathecal inflammation, and could be important in diagnostically undefined cases.

Free D-aspartate regulates neuronal dendritic morphology, synaptic plasticity, gray matter volume and brain activity in mammals

D-aspartate (D-Asp) is an atypical amino acid, which is especially abundant in the developing mammalian brain, and can bind to and activate N-methyl-D-Aspartate receptors (NMDARs). In line with its pharmacological features, we find that mice chronically treated with D-Asp show enhanced NMDAR-mediated miniature excitatory postsynaptic currents and basal cerebral blood volume in fronto-hippocampal areas. In addition, we show that both chronic administration of D-Asp and deletion of the gene coding for the catabolic enzyme D-aspartate oxidase (DDO) trigger plastic modifications of neuronal cytoarchitecture in the prefrontal cortex and CA1 subfield of the hippocampus and promote a cytochalasin D-sensitive form of synaptic plasticity in adult mouse brains. To translate these findings in humans and consistent with the experiments using Ddo gene targeting in animals, we performed a hierarchical stepwise translational genetic approach. Specifically, we investigated the association of variation in the gene coding for DDO with complex human prefrontal phenotypes. We demonstrate that genetic variation predicting reduced expression of DDO in postmortem human prefrontal cortex is mapped on greater prefrontal gray matter and activity during working memory as measured with MRI. In conclusion our results identify novel NMDAR-dependent effects of D-Asp on plasticity and physiology in rodents, which also map to prefrontal phenotypes in humans.

The autonomic balance predicts cardiac responses after the first dose of fingolimod

BACKGROUND

Predictive markers of cardiac side effects would be helpful for the stratification and individualized monitoring of multiple sclerosis (MS) patients prescribed with fingolimod.

OBJECTIVE

To test whether the autonomic balance predicts a cardiac response after the first dose of fingolimod.

METHODS

A total of 55 consecutive relapsing-remitting MS (RRMS) patients underwent 'head-up tilt', Valsalva maneuver, deep breathing and handgrip tests before their first dose of fingolimod. The normalized unit of the high frequency (HF) component (HF normalized units; HFnu), reflecting mostly vagal activity; and the low frequency (LF) component (LF normalized units; LFnu) reflecting mostly sympathetic activity, were considered for the analysis of heart rate (HR) variability. The patients' HR and electrocardiographic parameters ((the interval between P wave and ventricular depolarization (PR); the interval between Q and T waves (QT)) were recorded during 6-hour post-dose monitoring.

RESULTS

We found significant correlations between measures of parasympathetic function and fingolimod-induced bradycardia. Subjects with higher Valsalva ratio and HR variation during deep breathing had, in fact, nadir HR ≤ 50 beats/minute (bpm) after the first fingolimod dose. Conversely, significant negative correlations were found between measures of sympathetic function and fingolimod-induced PR interval increase. Subjects with lower LFnu at rest and less increase of blood pressure on the handgrip test showed a PR interval increase > 20 ms after fingolimod.

CONCLUSIONS

Assessing autonomic control of cardiovascular functions can be useful to predict cardiac effects after the first fingolimod dose.

Interleukin-8 is associated with acute and persistent dysfunction after optic neuritis

Background:

Acute optic neuritis is often in association with multiple sclerosis (MS). Proinflammatory cytokines trigger neuronal damage in neuroinflammatory disorders but their role in optic neuritis is poorly investigated.

Objective:

The objective of this work is to investigate the associations of intrathecal contents of proinflammatory cytokines with transient and persistent dysfunctions after optic neuritis.

Methods:

In 50 MS patients followed for up to six months, cerebrospinal fluid (CSF) levels of IL-1β, TNF and IL-8 were determined, along with clinical, neurophysiological and morphological measures of optic neuritis severity.

Results:

Visual impairment, measured by high- and low-contrast visual acuity, and delayed visual-evoked potential (VEP) latencies were significantly correlated to IL-8 levels during optic neuritis. IL-8 at the time of optic neuritis was also associated with persistent demyelination and final axonal loss, inferred by VEP and optical coherence tomography measures, respectively. Contents of IL-8 were correlated to functional visual outcomes, being higher among patients with incomplete recovery. Multivariate analysis confirmed that IL-8 significantly predicted final visual acuity, at equal values of demographics and baseline visual scores.

Conclusion:

Our study points to IL-8 as the main inflammatory cytokine associated with demyelination and secondary neurodegeneration in the optic nerve after optic neuritis.

Phlebographic study does not show differences between patients with MS and control subjects

BACKGROUND AND PURPOSE

Hypothetical correlation between chronic cerebrospinal venous insufficiency and MS has gained the attention of patients and the scientific community. Studies performed by echo-color Doppler ultrasonography have shown different results, and it is necessary to use more objective diagnostic techniques. The aim of our study was to evaluate the presence of stenoses affecting azygos veins and internal jugular veins by use of venography in patients with MS.

MATERIALS AND METHODS

We recruited 2 groups of subjects who underwent venography: the study group included 29 patients with MS and the control group included 15 healthy volunteers. The ileo-lumbar plexus, the azygos, and the internal jugular veins were selectively catheterized. We considered any cross-sectional area reduction of the venous lumen >50% to be a significant stenosis. Furthermore, blood pressure was measured in the studied vessels at the stenotic internal jugular veins.

RESULTS

Selective venography showed at least 1 significant venous stenosis in 84% of subjects examined, without significant difference between the study group and the control group. Positive venography chronic cerebrospinal venous insufficiency patterns were found in 50% of all subjects examined, without any significant difference between the 2 groups. The multivariate logistic regression analysis failed to assess any significant association between the presence of a positive venography and MS condition. The difference between the median blood pressure of stenotic and nonstenotic internal jugular veins was not statistically significant (P = .46).

CONCLUSIONS

Our data exclude any direct correlation between chronic cerebrospinal venous insufficiency and MS because venous abnormalities were equally present in both groups.

Functional connectivity changes within specific networks parallel the clinical evolution of multiple sclerosis

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.

Interleukin-1β alters the sensitivity of cannabinoid CB1 receptors controlling glutamate transmission in the striatum

Proinflammatory cytokines such as tumor necrosis factor-α and interleukin-1β (IL1β) regulate both excitatory and inhibitory synaptic transmission in the central nervous system. The interaction between IL1β and endocannabinoid system (ECS) is also emerging, based on the evidence that IL1β effects on striatal spontaneous excitatory and inhibitory postsynaptic currents are regulated by transient receptor potential vanilloid 1 (TRPV1) channels, members of the ECS. Furthermore, IL1β has also been shown to control the sensitivity of cannabinoid CB1 receptors controlling GABA transmission (CB1Rs(GABA)) in the striatum. To better detail the synaptic action of IL1β, and to clarify its complex interaction with the ECS, here we investigated the possible interplay between IL1β and CB1Rs controlling glutamate transmission (CB1Rs(glu)), other critical elements of the ECS. Our results show that the sensitivity of CB1Rs(glu) is fully blocked in the presence of IL1β in corticostriatal brain slices, and that the protein kinase C/TRPV1 pathway is involved in this effect. IL1β failed to modulate the sensitivity of glutamate synapses to the stimulation of GABAB receptors. We also provided evidence that IL1β-CB1Rs(GABA) but not IL1β-CB1Rs(glu) interaction is under the control of the brain-derived neurotrophic factor (BDNF)/trkB signaling and of lipid raft composition, because BDNF gene partial deletion, pharmacological blockade of trkB and membrane cholesterol removal with methyl-β-cyclodextrin all blocked IL1β-mediated inhibition of CB1Rs(GABA) but left unaltered the sensitivity of CB1Rs(glu) to this cytokine. Our results provide further evidence that synaptic transmission and the ECS are regulated by IL1β in the striatum.

Abnormal NMDA receptor function exacerbates experimental autoimmune encephalomyelitis

BACKGROUND AND PURPOSE

Glutamate transmission is dysregulated in both multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE), the animal model of MS. A characteristic of EAE is increased glutamate transmission associated with up-regulation of AMPA receptors. However, little is known about the role of NMDA receptors in the synaptic modifications induced by EAE.

EXPERIMENTAL APPROACH

The contribution of NMDA receptors to the alterations of glutamate transmission and disease severity in EAE mice was assessed by means of neurophysiological, morphological, Western blot, metabolic and clinical score assessments.

KEY RESULTS

In our EAE mice, there was an NMDA receptor-dependent increase of glutamate release, associated with marked activation of the astroglia. Presynaptic NMDA receptors became overactive during EAE, increasing synaptic glutamate release by a mechanism dependent on voltage-gated sodium channels. By means of NAD(P)H autofluorescence analysis, we also found that EAE has a glutamate and NMDA receptor-dependent dysfunction of mitochondrial activity, which is known to contribute to the neurodegenerative damage of MS and EAE. Furthermore, pharmacological blockade of NMDA receptors in vivo ameliorated both synaptic transmission defects and of the clinical disease course of EAE mice, while EAE induced in mice with a genetically enhanced NMDA receptor signalling had opposite effects.

CONCLUSIONS AND IMPLICATIONS

Our data, showing both sensitization of NMDA receptors and their involvement in the progression of the EAE disease, supggest that pharmacological impairment of NMDA receptor signalling would be a component of a neuroprotection strategy in MS.

Local excision with adjuvant imatinib therapy for anorectal gastrointestinal stromal tumors

Rectal gastrointestinal stromal tumors (GISTs) are uncommon, and the role of local excision versus a more extensive resection after the advent of effective targeted chemotherapy with imatinib is not known. Our aim is to present two cases of large anorectal GIST treated with local excision through a new anterolateral trans-sphincteric approach followed by adjuvant therapy with imatinib. Two patients (both males, 68 and 63 years old) presented at our institution with anorectal GIST in the period October-November 2010. Their medical records, pathology results, and imaging studies were retrospectively reviewed. Both patients presented with an anterior perianal mass. Imaging studies were characteristic of GIST originating in the lower rectum, circumscribed by a pseudocapsule, and protruding into the ischiorectal fossa. Both patients underwent local excision via an anterolateral trans-sphincteric approach. Both tumors were removed intact, with microscopically negative margins. The maximum tumor diameter was 8 and 9 cm, and the diagnosis of GIST was confirmed by positive CD117 and CD34 staining in both cases. Both tumors had a high (>5/50HPF) mitotic index. The patients had an uneventful postoperative course and were discharged on days 5 and 6. Both patients were started on imatinib 400 mg bid postoperatively. Postoperative magnetic resonance imaging and positron emission tomography computed tomography were carried out at 12 months and did not reveal any signs of recurrence. The patients are currently disease-free at 24 and 23 months of follow-up. In selected cases, complete excision of rectal GIST with negative margins is feasible via a trans-sphincteric approach. With the use of adjuvant therapy, which is currently advocated in all high-risk cases, it is possible that local excision with its reduced morbidity may become a viable alternative, especially in patients who would otherwise require abdominoperineal excision such as the two presented here. Prospective studies with longer follow-up are needed to confirm adequate oncologic results.

Anatomical brain connectivity can assess cognitive dysfunction in multiple sclerosis

BACKGROUND

Brain disconnection plays a major role in determining cognitive disabilities in multiple sclerosis (MS). We recently developed a novel diffusion-weighted magnetic resonance imaging (DW-MRI) tractography approach, namely anatomical connectivitity mapping (ACM), that quantifies structural brain connectivity.

OBJECTIVE

Use of ACM to assess structural connectivity modifications in MS brains and ascertain their relationship with the patients' Paced-Auditory-Serial-Addition-Test (PASAT) scores.

METHODS

Relapsing-remitting MS (RRMS) patients (n = 25) and controls (n = 25) underwent MRI at 3T, including conventional images, T1-weighted volumes and DW-MRI. Volumetric scans were coregistered to fractional anisotropy (FA) images, to obtain parenchymal FA maps for both white and grey matter. We initiated probabilistic tractography from all parenchymal voxels, obtaining ACM maps by counting the number of streamlines passing through each voxel, then normalizing by the total number of streamlines initiated. The ACM maps were transformed into standard space, for statistical use.

RESULTS

RRMS patients had reduced grey matter volume and FA, consistent with previous literature. Also, we showed reduced ACM in the thalamus and in the head of the caudate nucleus, bilaterally. In our RRMS patients, ACM was associated with PASAT scores in the corpus callosum, right hippocampus and cerebellum.

CONCLUSIONS

ACM opens a new perspective, clarifying the contribution of anatomical brain disconnection to clinical disabilities in MS.

Prevalence and management of panic attacks during infliximab infusion in psoriatic patients

BACKGROUND

Psoriasis is a chronic, inflammatory skin disease associated with anxiety and depression. Infliximab (IFX) is a human/mouse chimeric anti-TNF-α antibody effective in the treatment of psoriasis.

OBJECTIVE

The aim of this study was to evaluate the prevalence of panic disorders in psoriatic patients during IFX infusions.

METHODS

A retrospective study was performed on patients affected with psoriasis who were treated with IFX from 2002 to 2011 at a single center. Panic disorders were defined using the clinical criteria of the Diagnostic and Statistical Manual of Mental Disorders, 4th edition. A population of dermatological patients under treatment with IVG, rituximab, apheresis, intravenous corticosteroids and antibiotics was considered as the control group.

RESULTS

A total of 141 patients were evaluated. Of these, 6 (4.25%) experienced panic attacks during the infusion; 16 (11.3%) had a medical history of panic attack and of those 5/16 (31%) experienced panic attacks during IFX infusion. In the control group panic attacks were not recorded.

CONCLUSION

We describe 6 cases of patients in whom panic attacks were triggered by IFX infusion. Premedication with oral benzodiazepine and a slow rate of infusion is recommended.

Oral fingolimod rescues the functional deficits of synapses in experimental autoimmune encephalomyelitis

BACKGROUND AND PURPOSE Alterations of glutamate-mediated synaptic transmission occur early during neuroinflammatory insults, and lead to degenerative neuronal damage in multiple sclerosis (MS) and also in experimental autoimmune encephalomyelitis (EAE), which is a murine model of MS. Fingolimod is an effective orally active agent for the treatment of MS, affecting lymphocyte invasion of the brain. However, it is still unclear if fingolimod can be neuroprotective in this disorder. EXPERIMENTAL APPROACH Using neurophysiological recordings and morphological evaluation of dendritic integrity, we evaluated the effects of oral fingolimod on the clinical score of EAE mice in order to determine whether the compound was associated with preservation of synaptic transmission. KEY RESULTS Oral fingolimod prevented and reversed the pre- and postsynaptic alterations of glutamate transmission in EAE mice. These effects were associated with a clear amelioration of the clinical deterioration seen in EAE mice, and with a significant inhibition of neuronal dendritic pathology. Fingolimod did not alter the spontaneous excitatory postsynaptic currents in control animals, suggesting that only the pathological processes behind the inflammation-induced defects in glutamate transmission were modulated by this compound. CONCLUSIONS AND IMPLICATIONS The beneficial effects of fingolimod on the clinical, synaptic and dendritic abnormalities of murine EAE might correlate with the neuroprotective actions of this agent, as observed in MS patients. LINKED ARTICLE This article is commented on by Gillingwater, pp. 858-860 of this issue. To view this commentary visit http://dx.doi.org/10.1111/j.1476-5381.2011.01612.x.

Cannabinoid receptor signalling in neurodegenerative diseases: a potential role for membrane fluidity disturbance

Type-1 cannabinoid receptor (CB(1)) is the most abundant G-protein-coupled receptor (GPCR) in the brain. CB(1) and its endogenous agonists, the so-called 'endocannabinoids (eCBs)', belong to an ancient neurosignalling system that plays important functions in neurodegenerative and neuroinflammatory disorders like Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis and multiple sclerosis. For this reason, research on the therapeutic potential of drugs modulating the endogenous tone of eCBs is very intense. Several GPCRs reside within subdomains of the plasma membranes that contain high concentrations of cholesterol: the lipid rafts. Here, the hypothesis that changes in membrane fluidity alter function of the endocannabinoid system, as well as progression of particular neurodegenerative diseases, is described. To this end, the impact of membrane cholesterol on membrane properties and hence on neurodegenerative diseases, as well as on CB(1) signalling in vitro and on CB(1) -dependent neurotransmission within the striatum, is discussed. Overall, present evidence points to the membrane environment as a critical regulator of signal transduction triggered by CB(1) , and calls for further studies aimed at better clarifying the contribution of membrane lipids to eCBs signalling. The results of these investigations might be exploited also for the development of novel therapeutics able to combat disorders associated with abnormal activity of CB(1).

Potential role of IL-13 in neuroprotection and cortical excitability regulation in multiple sclerosis

BACKGROUND

Inflammation triggers secondary neurodegeneration in multiple sclerosis (MS).

OBJECTIVES

It is unclear whether classical anti-inflammatory cytokines have the potential to interfere with synaptic transmission and neuronal survival in MS.

METHODS

Correlation analyses between cerebrospinal fluid (CSF) contents of anti-inflammatory cytokines and molecular, imaging, clinical, and neurophysiological measures of neuronal alterations were performed.

RESULTS

Our data suggest that interleukin-13 (IL-13) plays a neuroprotective role in MS brains. We found, in fact, that the levels of IL-13 in the CSF of MS patients were correlated with the contents of amyloid-β(1-42). Correlations were also found between IL-13 and imaging indexes of axonal and neuronal integrity, such as the retinal nerve fibre layer thickness and the macular volume evaluated by optical coherence tomography. Furthermore, the levels of IL-13 were related to better performance in the low-contrast acuity test and Multiple Sclerosis Functional Composite scoring. Finally, by means of transcranial magnetic stimulation, we have shown that GABAA-mediated cortical inhibition was more pronounced in patients with high IL-13 levels in the CSF, as expected for a neuroprotective, anti-excitotoxic effect.

CONCLUSIONS

The present correlation study provides some evidence for the involvement of IL-13 in the modulation of neuronal integrity and synaptic function in patients with MS.

Quality of life, depression and fatigue in mildly disabled patients with relapsing-remitting multiple sclerosis receiving subcutaneous interferon beta-1a: 3-year results from the COGIMUS (COGnitive Impairment in MUltiple Sclerosis) study

BACKGROUND

The precise relationships among quality of life, depression, fatigue and cognitive impairment in multiple sclerosis (MS) are complex and poorly understood.

OBJECTIVE

To assess the effects of subcutaneous interferon beta-1a on quality of life, depression and fatigue over 3 years in the COGIMUS study, and to examine the relationship between these outcomes and baseline cognitive status.

METHODS

COGIMUS was an observational 3-year trial assessing cognitive function in 459 patients with relapsing-remitting MS treated with subcutaneous interferon beta-1a.

RESULTS

In total, 331 patients completed the study (168 received interferon beta-1a, 44 µg subcutaneously three times weekly, and 163 received interferon beta-1a, 22 µg subcutaneously three times weekly). Mean MS Quality of Life-54 (MSQoL-54) composite scores did not change over time. There were no significant differences between groups in MSQoL-54 composite scores when patients were grouped by treatment dose and baseline cognitive status. Mean (standard deviation) Hamilton Depression Rating Scale score decreased from 6.8 (4.9) at baseline to 5.8 (5.9) at year 3. Mean total Fatigue Impact Scale scores were low (<30) at all time points.

CONCLUSION

Quality of life, depression and fatigue remained largely stable over 3 years; no effects of treatment dose or baseline cognitive status were found.

Risk of acute promyelocytic leukemia in multiple sclerosis: coding variants of DNA repair genes

BACKGROUND

Single nucleotide polymorphisms (SNPs) in double-strand break repair genes may alter DNA repair capacity and, in turn, confer predisposition to leukemia. We analyzed polymorphic variants of DNA repair and detoxification genes in patients with multiple sclerosis (MS) who developed secondary acute promyelocytic leukemia (sAPL), in most cases after treatment with mitoxantrone (MTZ).

METHODS

Using MassARRAY high-throughput DNA analysis with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, we genotyped patients with sAPL (n=20) developed after treatment of MS (18 out 20 treated with MTZ) for the presence of 210 SNPs of 22 genes mostly involved in DNA repair and drug detoxification. Patients with MS who did not develop sAPL including 41 treated with MTZ (n=253 and 41, respectively) and healthy blood donors (n=310) were also genotyped as controls.

RESULTS

We observed risk allele frequency between MS and sAPL for BRCA2 (rs1801406): 6% and 26%, p=0.007; XRCC5 (rs207906): 2.5% and 15%, p=0.016; CYP3A4 (rs2740574): 4.5% and 25%, p=0.0035. The association of homozygous variants of BRCA2 and XRCC5 yielded higher risk of sAPL (MS vs sAPL: 0.4% and 18%, p=0.001). We also observed a significant association between a SNP in the promoter region (rs2740574) of CYP3A4, an enzyme involved in the metabolism of chemotherapeutic agents and development of sAPL.

CONCLUSIONS

Increased susceptibility to develop sAPL in patients with MS receiving MTZ may be linked to genetic variants in DNA repair and drug-metabolizing enzymes that result in impaired detoxification of chemotherapy or inefficient repair of drug-induced genetic damage.

Transient receptor potential vanilloid 1 channels control acetylcholine/2-arachidonoylglicerol coupling in the striatum

The neurotransmitter acetylcholine (Ach) controls both excitatory and inhibitory synaptic transmission in the striatum. Here, we investigated the involvement of the endocannabinoid system in Ach-mediated inhibition of striatal GABA transmission, and the potential role of transient receptor potential vanilloid 1 (TRPV1) channels in the control of Ach-endocannabinoid coupling. We found that inhibition of Ach degradation and direct pharmacological stimulation of muscarinic M1 receptors reduced striatal inhibitory postsynaptic currents (IPSCs) through the stimulation of 2-arachidonoylglicerol (2AG) synthesis and the activation of cannabinoid CB1 receptors. The effects of M1 receptor activation on IPSCs were occlusive with those of metabotropic glutamate receptor 5 stimulation, and were prevented in the presence of capsaicin, agonist of TRPV1 channels. Elevation of anandamide (AEA) tone with URB597, a blocker of fatty acid amide hydrolase, mimicked the effects of capsaicin, indicating that endogenous AEA acts as an endovanilloid substance in the control of M1-dependent 2AG-mediated synaptic effects in the striatum. Accordingly, both capsaicin and URB597 effects were absent in mice lacking TRPV1 channels. Pharmacological interventions targeting AEA metabolism and TRPV1 channels might be considered alternative therapeutic routes in disorders of striatal cholinergic or endocannabinoid neurotransmission.

Antiacquaporin 4 antibodies detection by different techniques in neuromyelitis optica patients

Background: Antibodies against aquaporin-4 (AQP4), a water channel particularly expressed on perivascular astrocytic podocytes, are proposed as a marker for the diagnosis of neuromyelitis optica (NMO). However, a consensus on seroprevalence and optimal detection method has not yet been reached.

Objectives: To investigate the performance of different assays to detect anti-AQP4 antibodies.

Methods: We set up five different assays. Two of them were capable to detect perivascular IgG reactivity on brain tissue by immunofluorescence (NMO-IgG). Other three assays have been set to detect anti-AQP4 antibodies: immunofluorescence and flow cytometry on AQP4-expressing cells, and a radioimmunoprecipitation assay. We assessed sensitivity and specificity of these assays by interrogating sera of 33 NMO patients, 13 patients at high risk to develop NMO (hrNMO), 6 patients affected by acute partial transverse myelitis (APTM), 20 patients with multiple sclerosis (MS), and 67 age- and sex-matched healthy controls.

Results: We found that the presence of serum NMO-IgG and anti-AQP4 reactivity is almost exclusively restricted to patients with NMO and hrNMO. Seroprevalence and sensitivity ranged from 30 to 47%, depending on the assay. Specificity ranged from 95 to 100%. Comparing results obtained in the five assays, we noticed lack of concordance in some samples.

Conclusions: Detection of NMO-IgG or anti-AQP4 antibodies may represent a valuable tool to assist neurologists in the differential diagnosis between patients with NMO, hrNMO, APTM, or MS. The current lack of a gold standard to detect anti-AQP4 antibodies implies the necessity to standardize the detection of these antibodies.