Refractory chronic migraine: is drug withdrawal necessary before starting a therapy with onabotulinum toxin type A?

Onabotulinum toxin A (BT-A) is now one of the authorized prophylaxis treatments for chronic migraine (CM) thanks to previous clinical trials, which usually required a pharmacologic washout as a precondition for demonstrating its efficacy. Aim of our study was to assess the efficacy in daily clinical practice of BT-A injections in refractory CM patients, regardless of medication overuse without any standardized withdrawal protocol and without stopping the ongoing prophylaxis treatment as well. We treated 44 refractory CM patients (37 females and 7 males) trimonthly without any modification in symptomatic, or prophylactic drug therapy. Main efficacy variables included number of headache, or migraine days and episodes, total cumulative headache hours, MIDAS and HIT-6 scores; all items were assessed at baseline and at the 12-, 24-, and 36-week follow-up. All variables showed a statistically significant improvement at week 36. In general, more than 50 % of patients had a good clinical outcome (including all improved patients, either partial or full responder) and that the percentage of drug abuser patients significantly decreased from 75 to 50 %, thanks to a spontaneous reduction of the symptomatic drug intake. Adverse events were uncommon and did not require treatment discontinuation. Onabotulinum toxin A treatment in refractory CM patients with unsatisfactory prophylactic drug treatments and pharmacological abuse is effective in improving clinical outcome and quality of life. This result may be achieved through a flexible pharmacologic approach tailored to each patient's needs; moreover, the patient himself can be often expected to reduce drug consumption spontaneously.

Down-sizing of neuronal network activity and density of presynaptic terminals by pathological acidosis are efficiently prevented by Diminazene Aceturate.

Local acidosis is associated with neuro-inflammation and can have significant effects in several neurological disorders, including multiple sclerosis, brain ischemia, spinal cord injury and epilepsy. Despite local acidosis has been implicated in numerous pathological functions, very little is known about the modulatory effects of pathological acidosis on the activity of neuronal networks and on synaptic structural properties. Using non-invasive MRI spectroscopy we revealed protracted extracellular acidosis in the CNS of Experimental Autoimmune Encephalomyelitis (EAE) affected mice. By multi-unit recording in cortical neurons, we established that acidosis affects network activity, down-sizing firing and bursting behaviors as well as amplitudes. Furthermore, a protracted acidosis reduced the number of presynaptic terminals, while it did not affect the postsynaptic compartment. Application of the diarylamidine Diminazene Aceturate (DA) during acidosis significantly reverted both the loss of neuronal firing and bursting and the reduction of presynaptic terminals. Finally, in vivo DA delivery ameliorated the clinical disease course of EAE mice, reducing demyelination and axonal damage. DA is known to block acid-sensing ion channels (ASICs), which are proton-gated, voltage-insensitive, Na(+) permeable channels principally expressed by peripheral and central nervous system neurons. Our data suggest that ASICs activation during acidosis modulates network electrical activity and exacerbates neuro-degeneration in EAE mice. Therefore pharmacological modulation of ASICs in neuroinflammatory diseases could represent a new promising strategy for future therapies aimed at neuro-protection.

Sensory tricks and brain excitability in cervical dystonia: a transcranial magnetic stimulation study.

BACKGROUND: Sensory tricks such as touching the face with fingertips often improve cervical dystonia [CD]. This study is to determine whether sensory tricks modulate motor cortex excitability, assessed by paired-pulse transcranial magnetic stimulation [p-pTMS]. METHODS: Eight patients with rotational CD underwent p-pTMS, at rest and when the sensory trick was applied. To test intracortical inhibition [ICI] and facilitation [ICF], the amplitude ratio between conditioned and unconditioned cortical motor evoked potentials was measured at several interstimulus intervals (ISI 1, 3, 15, and 20 ms) and compared with controls mimicking patients' sensory tricks. RESULTS: At rest, a significant ICF enhancement was found at ISIs 15 through 20 in patients compared with controls, whereas no significant ICI changes were observed. Sensory tricks significantly reduced the abnormal ICF in patients and did not induce any change in controls. CONCLUSIONS: In our CD patients, sensory tricks seem to improve dystonia through an inhibitory effect on motor cortex excitability.

Quantitative EMG of external urethral sphincter in neurologically healthy men with prostate pathology.

INTRODUCTION: There are no data on quantitative electromyography (EMG) of the external urethral sphincter (EUS) in men. The aim of this study was to obtain reference data from a group of neurologically healthy continent men with prostate pathology using a standardized technique. METHODS: Sixty-six subjects without neurological disorders were included. Motor unit potential (MUP) and interference pattern (IP) analysis were performed using multi-MUP and turns/amplitude techniques, respectively. RESULTS: Of 66 patients, 51 (mean age, 65.17; SD, 6.70) had localized prostate cancer (PCa), and 15 (mean age 61.67, SD 6.25) had benign prostate hyperplasia (BPH). Descriptive MUP parameters and IP-clouds were obtained, respectively in the BPH and PCa groups. No group differences were found. CONCLUSIONS: This study provides quantitative EMG measures of EUS functionality in continent men with prostate pathology. The data could be used as reference values for patients undergoing prostate surgery to identify postoperative changes in EUS function possibly influencing continence.

Cervical motion alterations and brain functional connectivity in cervical dystonia.

INTRODUCTION: Evaluating the neural correlates of sensorimotor control deficits in cervical dystonia (CD) is fundamental to plan the best treatment. This study aims to assess kinematic and resting-state functional connectivity (RS-FC) characteristics in CD patients relative to healthy controls. METHODS: Seventeen CD patients and 14 age-/sex-matched healthy controls were recruited. Electromagnetic sensors were used to evaluate dystonic pattern, mean/maximal cervical movement amplitude and joint position error with eyes open and closed, and movement quality during target reaching with the head. RS-fMRI was acquired to compare the FC of brain sensorimotor regions between patients and controls. In patients, correlations between motion analysis and FC data were assessed. RESULTS: CD patients relative to controls showed reduced mean and maximal cervical range of motion (RoM) in rotation both towards and against dystonia pattern and reduced total RoM in rotation both with eyes open and closed. They had less severe dystonia pattern with eyes open vs eyes closed. CD patients showed an altered movement quality and sensorimotor control during target reaching and a higher joint position error. Compared to controls, CD patients showed reduced FC between supplementary motor area (SMA), occipital and cerebellar areas, which correlated with lower cervical RoM in rotation both with eyes open and closed and with worse movement quality during target reaching. CONCLUSIONS: FC alterations between SMA and occipital and cerebellar areas may represent the neural basis of cervical sensorimotor control deficits in CD patients. Electromagnetic sensors and RS-fMRI might be promising tools to monitor CD and assess the efficacy of rehabilitative interventions.

Practice of yoga may cause damage of both sciatic nerves: a case report.

Sciatic nerve traumatic damage very rarely occurs bilaterally. We describe the case of a 67-year-old woman who reported a bilateral traumatic lesion of the sciatic nerve during practice of yoga. Nerve conduction studies showed a bilateral sciatic nerve neuropathy, mostly affecting the peroneal component. Lumbar plexus MRI documented regular anatomical features of the main principal nerve roots with bilateral T2 signal alteration of roots L4, L5 and S1 that extended into the sciatic nerves showing both increase in size, probably related to chronic injury of nerves, and an alteration in diffusion signal that suggested a recent acute overlapped process.

A fatal case of Churg-Strauss syndrome presenting with acute polyneuropathy mimicking Guillain-Barré syndrome.

A 64-year-old woman, with asthma and sinusal polyposis in her history, suddenly developed a painful polyneuropathy with diplopia. Nerve conduction studies, performed at the very onset of the neuropathy, could not definitely rule out a Guillain-Barré syndrome (GBS) and high-dose i.v. immunoglobulins were administered. Clinical and laboratory findings subsequently supported the diagnosis of Churg-Strauss syndrome; corticosteroid therapy was started and clinical stabilisation of neuropathy was apparently achieved. No indicators of unfavourable outcome were present at that time. Nevertheless, 30 days after the onset the patient acutely worsened with severe polyneuropathy relapse and fatal systemic diffusion to heart, kidney and mesenteric district, which a single cyclophosphamide pulse failed to control. This case highlights the possibility that a GBS-like onset of Churg-Strauss syndrome neuropathy should be regarded as a part of multiorgan, severe or even life-threatening vasculitic involvement, requiring the most aggressive treatments, regardless of the presence of recognised factors of poor outcome.

Human neural stem cells ameliorate autoimmune encephalomyelitis in non-human primates.

OBJECTIVE: Transplanted neural stem/precursor cells (NPCs) display peculiar therapeutic plasticity in vivo. Although the replacement of cells was first expected as the prime therapeutic mechanism of stem cells in regenerative medicine, it is now clear that transplanted NPCs simultaneously instruct several therapeutic mechanisms, among which replacement of cells might not necessarily prevail. A comprehensive understanding of the mechanism(s) by which NPCs exert their therapeutic plasticity is lacking. This study was designed as a preclinical approach to test the feasibility of human NPC transplantation in an outbreed nonhuman primate experimental autoimmune encephalomyelitis (EAE) model approximating the clinical and complex neuropathological situation of human multiple sclerosis (MS) more closely than EAE in the standard laboratory rodent. METHODS: We examined the safety and efficacy of the intravenous (IV) and intrathecal (IT) administration of human NPCs in common marmosets affected by human myelin oligodendrocyte glycoprotein 1-125-induced EAE. Treatment commenced upon the occurrence of detectable brain lesions on a 4.7T spectrometer. RESULTS: EAE marmosets injected IV or IT with NPCs accumulated lower disability and displayed increased survival, as compared with sham-treated controls. Transplanted NPCs persisted within the host central nervous system (CNS), but were also found in draining lymph nodes, for up to 3 months after transplantation and exhibited remarkable immune regulatory capacity in vitro. INTERPRETATION: Herein, we provide the first evidence that human CNS stem cells ameliorate EAE in nonhuman primates without overt side effects. Immune regulation (rather than neural differentiation) is suggested as the major putative mechanism by which NPCs ameliorate EAE in vivo. Our findings represent a critical step toward the clinical use of human NPCs in MS.

Sensory trick phenomenon in cervical dystonia: a functional MRI study.

Sensory trick may relieve dystonic symptoms in patients with idiopathic cervical dystonia (CD). We investigated the patterns of brain functional MRI (fMRI) during resting state, sensory trick simulation and sensory trick imagination in CD patients both with and without an effective sensory trick. We recruited 17 CD patients and 15 healthy controls. Nine patients (CD-trick) had an effective sensory trick, while 8 patients (CD-no-trick) did not. Cervical range of motion validated instrument assessed dystonic posture and sensory trick effect. Participants underwent resting state fMRI, which was repeated by patients while executing the sensory trick. Patients also performed an fMRI task in which they were asked to imagine a sensory trick execution. CD-trick and CD-no-trick patients were comparable in terms of CD severity. Applying the sensory trick, CD-trick patients significantly improved dystonic posture. CD-no-trick patients showed an increased functional connectivity of sensorimotor network relative to controls during classic resting state fMRI. During resting state fMRI with sensory trick, CD-trick patients showed a decrease of sensorimotor network connectivity. During the sensory trick imagination fMRI task, CD-trick relative to CD-no-trick patients increased the recruitment of cerebellum bilaterally. This study suggests a hyper-connectivity of sensorimotor areas during resting state in CD-no-trick subjects. In CD-trick patients, the sensory trick performance was associated with a decreased connectivity of the sensorimotor network. The increased activation of cerebellum in CD-trick patients during the sensory trick imagination suggests a possible role of this area in modulating cortical activity.

Gene therapy of metachromatic leukodystrophy reverses neurological damage and deficits in mice.

Metachromatic leukodystrophy (MLD) is a demyelinating lysosomal storage disorder for which new treatments are urgently needed. We previously showed that transplantation of gene-corrected hematopoietic stem progenitor cells (HSPCs) in presymptomatic myeloablated MLD mice prevented disease manifestations. Here we show that HSC gene therapy can reverse neurological deficits and neuropathological damage in affected mice, thus correcting an overt neurological disease. The efficacy of gene therapy was dependent on and proportional to arylsulfatase A (ARSA) overexpression in the microglia progeny of transplanted HSPCs. We demonstrate a widespread enzyme distribution from these cells through the CNS and a robust cross-correction of neurons and glia in vivo. Conversely, a peripheral source of enzyme, established by transplanting ARSA-overexpressing hepatocytes from transgenic donors, failed to effectively deliver the enzyme to the CNS. These results indicate that the recruitment of gene-modified, enzyme-overexpressing microglia makes the enzyme bioavailable to the brain and makes therapeutic efficacy and disease correction attainable. Overall, our data provide a strong rationale for implementing HSPC gene therapy in MLD patients.

Disruption of Mtmr2 produces CMT4B1-like neuropathy with myelin outfolding and impaired spermatogenesis.

Mutations in MTMR2, the myotubularin-related 2 gene, cause autosomal recessive Charcot-Marie-Tooth (CMT) type 4B1, a demyelinating neuropathy with myelin outfolding and azoospermia. MTMR2 encodes a ubiquitously expressed phosphatase whose preferred substrate is phosphatidylinositol (3,5)-biphosphate, a regulator of membrane homeostasis and vesicle transport. We generated Mtmr2-null mice, which develop progressive neuropathy characterized by myelin outfolding and recurrent loops, predominantly at paranodal myelin, and depletion of spermatids and spermatocytes from the seminiferous epithelium, which leads to azoospermia. Disruption of Mtmr2 in Schwann cells reproduces the myelin abnormalities. We also identified a novel physical interaction in Schwann cells, between Mtmr2 and discs large 1 (Dlg1)/synapse-associated protein 97, a scaffolding molecule that is enriched at the node/paranode region. Dlg1 homologues have been located in several types of cellular junctions and play roles in cell polarity and membrane addition. We propose that Schwann cell-autonomous loss of Mtmr2-Dlg1 interaction dysregulates membrane homeostasis in the paranodal region, thereby producing outfolding and recurrent loops of myelin.

Electrospun micro- and nanofiber tubes for functional nervous regeneration in sciatic nerve transections.

BACKGROUND: Although many nerve prostheses have been proposed in recent years, in the case of consistent loss of nervous tissue peripheral nerve injury is still a traumatic pathology that may impair patient's movements by interrupting his motor-sensory pathways. In the last few decades tissue engineering has opened the door to new approaches;: however most of them make use of rigid channel guides that may cause cell loss due to the lack of physiological local stresses exerted over the nervous tissue during patient's movement. Electrospinning technique makes it possible to spin microfiber and nanofiber flexible tubular scaffolds composed of a number of natural and synthetic components, showing high porosity and remarkable surface/volume ratio. RESULTS: In this study we used electrospun tubes made of biodegradable polymers (a blend of PLGA/PCL) to regenerate a 10-mm nerve gap in a rat sciatic nerve in vivo. Experimental groups comprise lesioned animals (control group) and lesioned animals subjected to guide conduits implantated at the severed nerve stumps, where the tubular scaffolds are filled with saline solution. Four months after surgery, sciatic nerves failed to reconnect the two stumps of transected nerves in the control animal group. In most of the treated animals the electrospun tubes induced nervous regeneration and functional reconnection of the two severed sciatic nerve tracts. Myelination and collagen IV deposition have been detected in concurrence with regenerated fibers. No significant inflammatory response has been found. Neural tracers revealed the re-establishment of functional neuronal connections and evoked potential results showed the reinnervation of the target muscles in the majority of the treated animals. CONCLUSION: Corroborating previous works, this study indicates that electrospun tubes, with no additional biological coating or drug loading treatment, are promising scaffolds for functional nervous regeneration. They can be knitted in meshes and various frames depending on the cytoarchitecture of the tissue to be regenerated. The versatility of this technique gives room for further scaffold improvements, like tuning the mechanical properties of the tubular structure or providing biomimetic functionalization. Moreover, these guidance conduits can be loaded with various fillers like collagen, fibrin, or self-assembling peptide gels or loaded with neurotrophic factors and seeded with cells. Electrospun scaffolds can also be synthesized in different micro-architectures to regenerate lesions in other tissues like skin and bone.

Oligodendroglial progenitor cell therapy limits central neurological deficits in mice with metachromatic leukodystrophy.

This work describes the first successful oligodendrocyte-based cell therapy for presymptomatic arylsulfatase A (ARSA) null neonate mice, a murine model for human metachromatic leukodystrophy (MLD). We found that oligodendrocyte progenitors (OLPs) engrafted and survived into adulthood when transplanted in the neonatal MLD brain. Transplanted cells integrated nondisruptively, did not produce tumors, and survived as proteolipid protein- and MBP-positive postmitotic myelinating oligodendrocytes (OLs) intermingled with endogenous MLD OLs within the adult MLD white matter. Transplanted MLD mice had reduced sulfatide accumulation in the CNS, increased brain ARSA activity, and full prevention of the electrophysiological and motor deficits that characterize untreated MLD mice. Our results provide direct evidence that healthy OLPs can tolerate the neurotoxic accumulation of sulfatides that evolves during the postnatal development of the MLD brain and contribute to OL cell replacement to limit the accumulation of sulfatides and the evolution of CNS defects in this lysosomal storage disease mouse model.

Correction of metachromatic leukodystrophy in the mouse model by transplantation of genetically modified hematopoietic stem cells.

Gene-based delivery can establish a sustained supply of therapeutic proteins within the nervous system. For diseases characterized by extensive CNS and peripheral nervous system (PNS) involvement, widespread distribution of the exogenous gene may be required, a challenge to in vivo gene transfer strategies. Here, using lentiviral vectors (LVs), we efficiently transduced hematopoietic stem cells (HSCs) ex vivo and evaluated the potential of their progeny to target therapeutic genes to the CNS and PNS of transplanted mice and correct a neurodegenerative disorder, metachromatic leukodystrophy (MLD). We proved extensive repopulation of CNS microglia and PNS endoneurial macrophages by transgene-expressing cells. Intriguingly, recruitment of these HSC-derived cells was faster and more robust in MLD mice. By transplanting HSCs transduced with the arylsulfatase A gene, we fully reconstituted enzyme activity in the hematopoietic system of MLD mice and prevented the development of motor conduction impairment, learning and coordination deficits, and neuropathological abnormalities typical of the disease. Remarkably, ex vivo gene therapy had a significantly higher therapeutic impact than WT HSC transplantation, indicating a critical role for enzyme overexpression in the HSC progeny. These results indicate that transplantation of LV-transduced autologous HSCs represents a potentially efficacious therapeutic strategy for MLD and possibly other neurodegenerative disorders.

Both laminin and Schwann cell dystroglycan are necessary for proper clustering of sodium channels at nodes of Ranvier.

Nodes of Ranvier are specialized axonal domains, at which voltage-gated sodium channels cluster. How axons cluster molecules in discrete domains is mostly unknown. Both axons and glia probably provide constraining mechanisms that contribute to domain formation. Proper sodium channel clustering in peripheral nerves depends on contact from Schwann cell microvilli, where at least one molecule, gliomedin, binds the sodium channel complex and induces its clustering. Furthermore, mice lacking Schwann cell dystroglycan have aberrant microvilli and poorly clustered sodium channels. Dystroglycan could interact at the basal lamina or at the axonglial surface. Because dystroglycan is a laminin receptor, and laminin 2 mutations [merosin-deficient congenital muscular dystrophy (MDC1A)] cause reduced nerve conduction velocity, we asked whether laminins are involved. Here, we show that the composition of both laminins and the dystroglycan complex at nodes differs from that of internodes. Mice defective in laminin 2 have poorly formed microvilli and abnormal sodium clusters. These abnormalities are similar, albeit less severe, than those of mice lacking dystroglycan. However, mice lacking all Schwann cell laminins show severe nodal abnormalities, suggesting that other laminins compensate for the lack of laminin 2. Thus, although laminins are located at a distance from the axoglial junction, they are required for proper clustering of sodium channels. Laminins, through their specific nodal receptors and cytoskeletal linkages, may participate in the formation of mechanisms that constrain clusters at nodes. Finally, abnormal sodium channel clusters are present in a patient with MDC1A, providing a molecular basis for the reduced nerve conduction velocity in this disorder.

Post cardiac surgery diaphragmatic spasm successfully treated with gabapentin.

We describe the case of an 82 year old woman developing severe respiratory functional impairment after open heart surgery and subsequent surgical pericardial drainage inducing diaphragmatic spasm and successfully treated with gabapentin.

Sativex(®) and clinical-neurophysiological measures of spasticity in progressive multiple sclerosis.

Despite the proven efficacy of Sativex(®) (9-delta-tetrahydrocannabinol plus cannabidiol) oromucosal spray in reducing spasticity symptoms in multiple sclerosis (MS), little is known about the neurophysiological correlates of such effects. The aim of the study was to investigate the effects of Sativex on neurophysiological measures of spasticity (H/M ratio) and corticospinal excitability in patients with progressive MS. This was a randomized, double-blind, placebo-controlled, crossover study. Consecutive subjects with progressive MS and lower limb spasticity referred to our center were randomized to 4 weeks' treatment (including 2 weeks' titration) with Sativex or placebo, with crossover after a 2-week washout. Clinical and neurophysiological measures (H/M ratio and cortical excitability) of spasticity were assessed. The H/M ratio was the primary outcome, with sample size calculation of 40 patients. Of 44 recruited patients, 34 were analyzed due to 6 drop-outs and 4 exclusions, which lowered the power of the study to show differences between treatments. Neurophysiological measures did not differ significantly according to treatment and did not correlate significantly with clinical response. Response on the modified Ashworth scale (at least 20 % improvement) was significantly more frequent after Sativex than placebo (50 vs 23.5 %; p = 0.041; McNemar). Side effects did not differ significantly according to treatment. Our findings confirm the clinical benefit of Sativex on MS spasticity. The lack of corresponding changes in corticospinal excitability and on the monosynaptic component, of the stretch reflex, although in a limited sample size, points to the involvement of other spinal and supraspinal mechanisms in the physiopathology of spasticity in progressive MS.

Mesoangioblast delivery of miniagrin ameliorates murine model of merosin-deficient congenital muscular dystrophy type 1A.

BACKGROUND: Merosin-deficient congenital muscular dystrophy type-1A (MDC1A) is characterized by progressive muscular dystrophy and dysmyelinating neuropathy caused by mutations of the α2 chain of laminin-211, the predominant laminin isoform of muscles and nerves. MDC1A has no available treatment so far, although preclinical studies showed amelioration of the disease by the overexpression of miniagrin (MAG). MAG reconnects orphan laminin-211 receptors to other laminin isoforms available in the extracellular matrix of MDC1A mice. METHODS: Mesoangioblasts (MABs) are vessel-associated progenitors that can form the skeletal muscle and have been shown to restore defective protein levels and motor skills in animal models of muscular dystrophies. As gene therapy in humans still presents challenging technical issues and limitations, we engineered MABs to overexpress MAG to treat MDC1A mouse models, thus combining cell to gene therapy. RESULTS: MABs synthesize and secrete only negligible amount of laminin-211 either in vitro or in vivo. MABs engineered to deliver MAG and injected in muscles of MDC1A mice showed amelioration of muscle histology, increased expression of laminin receptors in muscle, and attenuated deterioration of motor performances. MABs did not enter the peripheral nerves, thus did not affect the associated peripheral neuropathy. CONCLUSIONS: Our study demonstrates the potential efficacy of combining cell with gene therapy to treat MDC1A.