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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.

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.

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. Muscle Nerve 50: 571–576, 2014

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. © 2014 International Parkinson and Movement Disorder Society

Intraoperative neuromonitoring (IOM) allow the assessment of spinal integrity during thoracoabdominal aneurysm (TAAA) surgery, giving the opportunity to predict or help to prevent spinal ischemia (SCI). The reliability of IOM depends on excluding confounding factors and on warning criteria. Our aims were to investigate the sensitivity and specificity of IOM for SCI and to verify if the study of compound motor action potential (CMAP) is reliable in the identification of limb ischemia and improve IOM sensitivity for SCI. One-hundred consecutive patients (mean 64.3 yrs) undergoing TAAAs surgery between February 2016 and March 2018 were studied prospectively. IOM included motor evoked potentials (MEPs), somatosensory evoked potentials (SEPs), popliteal potentials and CMAPs. MEPs and SEPs were recordable in 99% of cases. MEPs showed transient changes in 49.5% and persistent decrease in 16.2% (3% unilateral). All of 4 patients with persistent bilateral MEPs deterioration and without alteration of peripheral potentials or arm MEPs developed paraplegia. Persistent bilateral MEPs changes, especially without concurrent peripheral alterations, are at high risk of SCI and justify prompt interventions for maximize spinal perfusion. The improvement of the accuracy in the identification of peripheral ischemia could help to clarify which MEPs alterations correlate with neurologic deficits.

Botulinum toxin type A (BT-A) is known to be effective in improving focal spasticity; a few data are available on BT-A efficacy in improving function and quality of life in Multiple Sclerosis (MS). To evaluate in MS patients presenting with focal spasticity the grade of achievement of the predefined goals through the treatment with BT-A and physiotherapy a longitudinal prospective study was drawn in 11 patients; for each patient it was fixed an individualized rehabilitative program and BT-A was administered depending on spasticity pattern. The evaluation of the adequate achievement of the target was done at week 4 using the Goal Attainment Scale (GAS). Specific scales were applied depending on the function or disability domain involved. All of them had a progressive form of MS; EDSS was 6.5 mean (4–8). 8 patients had as target gait improvement, 2 postural changes and 1 posture improving. 9 out of 11 reached the fixed target, 6 of them with gait improvement as target. Our data suggest that an integrated, multidisciplinary approach in treating focal spasticity is effective for reaching the individualized objective targeted on actual needs of single patient. This is the first step for a subsequent evaluation of a real impact of our intervention in reducing global disability of MS patients.

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.

Objectives The time course of mu and beta sensorimotor rhythms, with event-related desynchronisation (ERD) to preparation and execution of voluntary movement followed by synchronisation (ERS) after movement, is considered to indicate cortical activation and idling, respectively. We investigated ERD and ERS in amyotrophic lateral sclerosis (ALS) patients and the relationship with anatomical and neurophysiological measures of corticospinal tract damage. Methods Pre-movement mu and beta ERD, and post-movement beta ERS were analysed in 16 ALS patients and 15 healthy controls performing self-paced brisk right thumb extensions. Apparent diffusion coefficient (ADC) of corticospinal tract was measured with magnetic resonance imaging (MRI). Motor-evoked potentials (MEPs) to the right abductor pollicis brevis were obtained using transcranial magnetic stimulation (TMS). Results Movement-related electromyographic activity was similar in the two groups. Post-movement ERS was significantly reduced in ALS group and negatively correlated with the amount of corticospinal damage as from MRI and TMS measures. ERD did not significantly differ between groups. Conclusions Alterations of cortical activity in ALS patients were limited to the post-movement phase, as indicated by reduced ERS, and could be linked to reduced cortical inhibition rather than to generalised hyperexcitability. Significance The correlation between ERS and corticospinal damage severity might be interpreted as a functional compensation or dysfunction of inhibitory systems paralleling corticospinal damage.

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.

Botulinum toxin type-A is currently thought to be effective and safe for hemifacial spasm (HFS). The pre-synaptic block of acetylcholine release at the neuromuscular junction induces depression of orbicularis oculi muscle compound motor action potential (CMAP). The aim of our study was to evaluate at what extent end-plate functional recovery is possible even in botulinum toxin treatments lasting up to 15 years. We examined 81 outpatients with primary HFS (mean treatment duration = 7.2 ± 4.2 years) who underwent neurophysiologic study, once clinical effect of the previous treatment had vanished. The mean CMAP amplitude, mean rectified amplitude of response 1 (R1) of the blink reflex and area of response 2 (R2) of treated orbicularis oculi muscle were measured in comparison to the controlateral side. Mean amplitude of the above mentioned parameters was slightly lower (about 20%; p < 0.001) in the treated side at the end of the follow-up period (4.7 ± 1.7 months). The CMAP amplitude reduction weakly correlated with the interval from last treatment, while other neurophysiologic parameters did not change due to treatment duration or total toxin amount. Our study demonstrates that botulinum toxin affects compound motor action potential and blink-reflex responses for at least 4-5 months in HFS patients. The residual block is slight and does not increase with repeated injections after several years of treatment. Our study, beside confirming the long-term efficacy of botulinum toxin treatment for HFS, provides neurophysiologic evidence that therapeutic effect may be obtained without hindering the regenerative potential of the nerve-muscle complex.

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.

Onabotulinumtoxin-A (BT-A) is an authorised prophylactic therapy in chronic migraine (CM). Its efficacy has been proved by both clinical trials and observational studies. Few data are still available on the efficacy of BT-A injection and the most adequate treatment interval after the first year of follow-up. This study aimed to verifyefficacy, safety and the most adequate timing of BT-A injections in CM patients during the second year of treatment. we evaluated 20 CM patients with medication overuse MO (17 females and 3 males) treated with BT-A for 24 months. After the fourth treatment, we decided to retreat responder patients based on their clinical result. Main efficacy variables were registered at each visit, including days of headache/migraine, total cumulative headache hours, MIDAS and HIT-6 scores, together with symptomatic drugs intake. All variables at week 24 maintained the improvement evidenced at week 12. Adverse events were rare and did not require treatment discontinuation. Most of the patients (n = 13) continued to perform trimestral injections, 5 patients every 4 months and 2 patients every 6 months. BT-A in CM patients is effective even after two years of treatment when administered with an individualised interval according to the clinical outcome.

This study describes our experience with neuromonitoring in thoracoabdominal aortic aneurysms (TAAA) repair, focusing on the set up of a monitoring protocol, aimed to optimize the detection of spinal cord ischemia. A retrospective observational study was carried out on 62 consecutive patients (37 men; mean age 63.8 years) undergoing TAAA repair between February 2016 and March 2017. All patients underwent Motor Evoked Potentials (MEPs), Somatosensory Evoked Potentials (SSEPs), neurophysiological monitoring of peripheral ischemia, and continuous control of other intraoperative variables. The mortality rate was 9.6%, and the incidence of immediate and delayed neurological deficits was 6.4% and 3.2% respectively. Significant MEP changes occurred in 41.6% of patients, recovering in 85% of cases. Permanent MEPs changes occurred in 3 patients (15%), 2 of them developed immediate paraplegia. Significant SSEPs changes occurred in 6 patients (12.2%) and recovered in all but one, awaking with paraplegia. False negative and positive rate were both 1.6%. Our data are consistent with the literature. However, a consensus is still lacking with regard to an intraoperative protocol for monitoring, which limits the comparison of different studies. Our method demonstrated a good reliability and could contribute to the setup of a consensus protocol.

A 31-months old child was admitted with a 4-day history of fever and weakness. The initial neurological examination revealed a meningeal syndrome with neck stiffness, without consciousness impairment. Head CT was normal. Analysis of CSF showed only increased level of proteins. Based on clinical manifestations, an empirical antibiotics and antiviral therapy was started. During the following 48 h, a progressive flaccid tetraparesis occurred. An ENG/EMG study was performed to exclude a peripheral involvement that showed decreased CMAP amplitude, partial motor conduction blocks/pseudo-blocks signs in the forearm segment of median and ulnar nerves and absence of F-waves. The MRI of spinal cord showed enhancement of the cauda equina. These data led to a diagnosis of polyradiculonevritis and a treatment with IVIG was performed with an initial stabilization of the neurological symptoms. At 24 days, patient’s symptoms did not further recover and ENG/EMG was repeated showing: diffuse absence of CMAPs, reduction of SAPs, active denervation in all muscles. The final diagnosis was AMSAN, and another cycle of IVIG was administered. As signs of meningeal irritation may be consistent with meningitis or other diseases, it is important to recognize atypical features of pediatric GBS spectrum syndromes to achieve early diagnosis and treatment.

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. Ann Neurol 2009;66:343–354

Metachromatic leukodystrophy (MLD) is a rare lysosomal storage disorder resulting from the inherited deficiency of the arylsulfatase A (ARSA) enzyme. Currently, no valid therapeutic options are available for affected patients. A thorough knowledge of disease progression in its diverse clinical variants, together with the identification of reliable prognostic factors, could be instrumental in accurate patient selection for new upcoming therapeutic opportunities, such as enzyme replacement and gene therapy. The described correlation between genotype and clinical presentation proved helpful in predicting patient's prognosis, only in the minority of MLD patients harboring common mutations. Molecular characterization of a cohort of 26 MLD patients allowed us to identify 18 mutations, excluding the common 0 and R alleles, 10 of which are rare and 8 are novel. By categorizing the rare mutations, we were able to confirm a correlation between ARSA gene mutations, age at onset and patterns of disease progression, not only in those patients bearing common mutations, but also in those carrying rare mutant alleles. Moreover, in the case of absent or delayed molecular diagnosis, or of newly identified mutations, the involvement of peripheral nervous system from disease onset proved to be a sensitive prognostic marker predicting a severe progression.

OBJECTIVE—The purpose of this study was to evaluate whether islet transplantation may stabilize polyneuropathy in uremic type 1 diabetic patients (end-stage renal disease [ESRD] and type 1 diabetes), who received a successful islet-after-kidney transplantation (KI-s). RESEARCH DESIGN AND METHODS—Eighteen KI-s patients underwent electroneurographic tests of sural, peroneal, ulnar, and median nerves: the nerve conduction velocity (NCV) index and amplitudes of both sensory action potentials (SAPs) and compound motor action potentials (CMAPs) were analyzed longitudinally at 2, 4, and 6 years after islet transplantation. Skin content of advanced glycation end products (AGEs) and expression of their specific receptors (RAGE) were also studied at the 4-year follow-up. Nine patients with ESRD and type 1 diabetes who received kidney transplantation alone (KD) served as control subjects. RESULTS—The NCV score improved in the KI-s group up to the 4-year time point (P = 0.01 versus baseline) and stabilized 2 years later, whereas the same parameter did not change significantly in the KD group throughout the follow-up period or when a cross-sectional analysis between groups was performed. Either SAP or CMAP amplitudes recovered in the KI-s group, whereas they continued worsening in KD control subjects. AGE and RAGE levels in perineurium and vasa nervorum of skin biopsies were lower in the KI-s than in the KD group (P < 0.01 for RAGE). CONCLUSIONS—Islet transplantation seems to prevent long-term worsening of polyneuropathy in patients with ESRD and type 1 diabetes who receive islets after kidney transplantation. No statistical differences between the two groups were evident on cross-sectional analysis. A reduction in AGE/RAGE expression in the peripheral nervous system was shown in patients receiving islet transplantation.

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.

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. TransplantedMLDmice had reduced sulfatide accumulation in the CNS, increased brain ARSA activity, and full prevention of the electrophysiological and motor deficits that characterize untreatedMLDmice. 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.

We tested cortical motor evoked potentials (cMEPs) as a quantitative marker for in vivo monitoring of corticospinal tract damage in a murine multiple sclerosis model (experimental autoimmune encephalomyelitis, EAE). The cMEPs, previously standardized in naive C57BL/6 developing and adult mice, were studied longitudinally in adult EAE mice. Central conduction times (CCTs) increased significantly shortly before the earliest clinical signs developed (10 days postimmunization, dpi), with peak delay in acute EAE (20-40 dpi). In clinically stable disease (80 dpi), CCTs did not increase further, but cMEP amplitude declined progressively, with complete loss in >80% of mice at 120 dpi. Increase in CCT correlated with presence of inflammatory infiltrates and demyelination in acute EAE, whereas small or absent cMEPs were associated with continuing axonal damage in clinically-stabilized disease and beyond (>80 dpi). These results demonstrate that cMEPs are a useful method for monitoring corticospinal tract function in chronic-progressive EAE, and provide insight into the pathological substrate of the condition.

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.

We have used magnetic resonance imaging (MRI) and motor evoked potentials (MEPs) for monitoring disease progression within the CNS of the Twitcher mouse, the murine model for globoid cell leukodystrophy (GLD). GLD is a lysosomal storage disorder, resulting from galactocerebrosidase deficiency, causing central and peripheral myelin impairment, leading to death, usually during early infancy. Neuroradiological, electrophysiological, and pathological parameters of myelin maturation were evaluated in Twitcher mice between postnatal days 20 and 45. Healthy controls showed a gradual-appearance MRI T2-weighted hypointensity of the corpus callosum (CC) starting at about P30 and ending at about P37, whereas MRI of age-matched Twitcher mice showed a complete loss of the CC-related MRI signal. MEPs allowed the functional assessment of myelin maturation within corticospinal motor pathways and showed a progressive deterioration of MEPs in Twitcher mice with increased central conduction time (CCT; 5.12 +/- 0.49 msec at P27 to 6.45 +/- 1.96 msec at P32), whereas physiological CCT shortening was found in healthy controls (3.01 +/- 0.81 msec at P27 to 2.5 +/- 0.27 msec at P32). These findings were not paralleled by traditional histological stainings. Optical observation of Bielchowsky and Luxol fast blue-PAS stainings showed mild axonal/myelin deterioration of the Twitcher brain within this time frame. Our results demonstrate that serial MRI and MEP readings are sensitive evaluation tools for in vivo monitoring of dysmyelination in Twitcher mice and underscore their potential use for longitudinal evaluation of the therapeutic impact of gene and cell therapies on these animals.

A large multicentre clinical trial (PREEMPT) demonstrated the efficacy and safety of onabotulinumtoxin A for prophylactic treatment of chronic migraine (CM) in prophylactic drug-free patients. This study aimed to verify the efficacy of repetitive injections of onabotulinumtoxin A in CM patients with ineffective chronic poly-therapy. Patients and methods: we studied 45 CM patients (36 females and 9 males) taking multiple prophylactic/symptomatic medications who were treated with onabotulinumtoxin-A for a follow up period of 9 months. The overall dose ranged between 155 and 180 U administered in 31–36 sites following PREEMPT protocol, repeated at 12 weeks intervals. The main evaluated variables to establish drug efficacy included number of headache/migraine days and episodes, total cumulative headache hours, MIDAS and HIT-6 scores; all items were assessed at baseline and after 12–24–36 weeks during follow-up. Results: all variables showed statistically significant changes after 36-weeks time-point. We observed a responder rate (partially responder plus completely responder patients) of about 40% after the first treatment; the rate reached 90% after the third treatment. Adverse events were uncommon and did not require treatment discontinuation. Conclusions: repeated treatments with onabotulinumtoxin A in CM patients with unsatisfactory prophylactic drug treatments, was very effective in improving all variables examined, determining a measurable positive impact on quality of life.

A classic hallmark of cervical dystonia (CD) is the improvement of dystonic symptoms during a specific maneuver, defined ‘sensory trick’ (ST). Even if the mechanism by which ST improves dystonia is not well understood, it is likely that cortical sensorimotor integration processes are involved. In a previous preliminary study, we evaluated the short latency afferent inhibition (SAI) in a group of CD patients and the effects of ST on the SAI profile. To date, we have increased our sample including 28 patients with primary CD (18 with ST, CD+, and 10 without ST, CD-) and 11 controls. The analysis of variance showed no significant differences between CD- patients and controls. On the contrary, a remarkable trend toward a reduced SAI was observed in CD+ patients when they did not perform ST. Interestingly, SAI was further reduced in CD+ patients when they performed ST, reaching a strong statistical relevance. Our results show the presence of an abnormal sensorimotor integration in CD+ patients. Furthermore, they prove that ST acts by modulating the abnormal link between sensory input and motor output.

We describe a 75-year-old woman affected by ichthyosis since childhood who developed bilateral lower limb distal muscle weakness resulting in foot deformities and gait disturbances during the last decade. Neurological examination showed equinovarus deformity with pied en griffe, distal motor and sensory impairment and areflexia at lower limbs. On upper limbs mild distal motor impairment and atrophy were present. EMG study revealed an axonal sensory motor polyneuropathy. Sural nerve biopsy showed a severe, predominantly axonal, neuropathy with many clusters of small myelinated fibers and some degree of chronic demyelination with small onion bulbs. Both her sister and the mother have a clinically similar peripheral neuropathy, but in the absence of ichtyosis. Familial history, prevalent motor lower limbs involvement, middle life onset with slow evolution, neurophysiological and neuropathological findings suggest the diagnosis of Charcot-Marie-Tooth disease type 2 (CMT 2). Nevertheless, biochemistry and cerebrospinal fluid analysis were performed to rule out known causes of axonal peripheral neuropathy. Ichthyosis has been reported to be associated with some neurological disorders characterized by the presence of peripheral neuropathy such as Krabbe leucodystrophy, Refsum disease, and Rud syndrome. To our knowledge no association has been described between CMT2 and ichthyosis. We believe interesting to point out the presence in our family of CMT2 and ichthyosis. Further studies are ongoing to better elucidate this association.

Peripheral neuropathy is one of the most common secondary complications of diabetes mellitus, causing severe and prolonged morbidity. However, clinical and experimental studies have reported that careful glucose control may prevent, stabilize, and/or reverse neuropathy and other chronic diabetic complications. Unfortunately, insulin therapy does not prevent the development or progression of chronic lesions in the vessels, kidneys, eyes, or nerves of the diabetic patient. There is great interest in investigating other forms of endocrine replacement therapy, such as transplantation of the pancreas or of the islets of Langerhans (IT). Diabetic polyneuropathy (DP) evolution is characterized by progressive demyelination and axonal loss and is manifested by signs and symptoms on physical examination and abnormalities in nerve conduction studies (NCS). NCS provide reliable, noninvasive, objective measures of peripheral nerve function and constitute the most important technique for the evaluation of the severity of DP in clinical trials. Several research groups have demonstrated that skin biopsy with measurement of intraepidermal nerve fiber density is another method minimally invasive and repeatable that provides direct pathologic evidence of axonal damage in diabetic neuropathy. Fifty-one consecutive IDDM patients with or without end stage renal disease were enrolled at the moment of islet (Is), kidney (KD), kidney-pancreas (KP) or kidney-islet (KI) transplantation. Patients underwent skin biopsy punch, neurologic examination and neurophysiological investigation. Particularly, 20 pts underwent KP tx, 16 KD tx, 10 islet tx and 5 KI. The patients were comparable for duration of diabetes, dialysis (when present), age, lipid profile. In half of the patients a follow-up of 2 years has been reached. After KP tx, and partially with KI, a complete normalization of glycometabolic control has been achieved, with statistically lower HbA1c in comparison with KD group (KP = 6.2; 0.1% vs. KD = 8.4; 0.5%; p

Study aim: the Ebf gene family has been implicated in several developmental processes, ranging from B-cell development to neuronal differentiation. As the murine Ebf2 gene is expressed in numerous sites of nervous system, Ebf2-null mice develop hypogonadotropic hypogonadism, due to defective migration of gonadotropin releasing hormone-synthesizing neurons, and a peripheral neuropathy as well. Therefore, we aimed to study whether electrophysiological tests would be able to detect abnormalities of peripheral nerve function. Methods: 2 groups of mice were studied, which consisted of 8 Ebf2-/- mice and 9 age-matched controls. The sciatic nerve was stimulated at the ankle and at the ischiatic notch; the compound motor action potential (cMAP) was recorded from the paw muscles with a pair of needle electrodes to measure the motor conduction velocity (MCV). Results: MCV mean values were lower in Ebf2-/-(21.8 m/sec; SD 2.9) than in controls (35.2 m/sec; SD 2.6) and the difference was significant (p

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by a progressive degeneration of the corticospinal tract motor neurons. Growing evidence, especially derived from studies in murine models, could suggest that ALS is a distal axonopathy in which axonal degeneration occurs early during the disease, preceding the degeneration of motoneuron soma in the ventral horn of the spinal cord and the onset of symptoms (Fischer et al., 2004; Dadon-Nachum et al., 2011). A combination of molecular and subcellular events, such as protein misfolding, oxidative damage, mitochondrial alterations, impairment of glutamate transmission leading to excitotoxicity, and axonal transport impairment has been implicated in motoneuron vulnerability in ALS (Ferraiuolo et al., 2011). These observations led to consider the neuromuscular junction (NMJ) as a major player in the initiation and progression of ALS. Aim of this study was to investigate the functionality of the NMJ through all the course of the disease in the hSOD1G93A ALS mouse model, by means of single-fiber electromyography (SFEMG) technique. A comprehensive neurophysiological investigation (including sciatic nerve conduction, MEPs by transcranial electrical stimulation and sSFEMG) was carried out on 5 WT and 5 hSOD1G93A mice, at different time-points (50-70-90-110 ± 3 PND). In the early pre-symptomatic phase (50 PND), hSOD1G93A mice presented a significant jitter elongation [MCD (mean ± SE): 18.36 ± 3.21 in hSOD1G93A, 8.23 ± 0.84 in WT; p 0.021] together with increased fiber density [FD (mean ± SE): 1.62 ± 0.17 in hSOD1G93A, 1.27 ± 0.10 in WT; p 0.117] when compared with controls, suggestive of recent reinnervation process. No difference were found in peripheral conduction and MEPs parameters at the same time-point. Our results show that the neuromuscular transmission of hSOD1G93A mice is altered since the early presymptomatic phase of the disease. This probably derive from an early denervation-reinnervation process resulting in immature collateral nerve terminals and instability of neuromuscular transmission. SFEMG seems to be more sensitive in detecting the early signs of the disease compared to the other neurophysiological techniques, and could be a valuable tool for monitoring the effectiveness of new experimental therapeutic approach.

IL-12 has been shown to be involved in the pathogenesis of Th1-mediated autoimmune diseases, but its role in antibody-mediated autoimmune pathologies is still unclear. We investigated the effects of exogenous and endogenous IL-12 in experimental autoimmune myasthenia gravis (EAMG). EAMG is an animal model for myasthenia gravis, a T cell-dependent, autoantibody-mediated disorder of neuromuscular transmission caused by antibodies to the muscle nicotinic acetylcholine receptor (AChR). Administration of IL-12 with Torpedo AChR (ToAChR) to C57BL/6 (B6) mice resulted in increased ToAChR-specific IFN-gamma production and increased anti-ToAChR IgG2a serum antibodies compared with B6 mice primed with ToAChR alone. These changes were associated with earlier and greater neurophysiological evidence of EAMG in the IL-12-treated mice, and reduced numbers of AChR. By contrast, when IL-12-deficient mice were immunized with ToAChR, ToAChR-specific Th1 cells and anti-ToAChR IgG2a serum antibodies were reduced compared to ToAChR-primed normal B6 mice, and the IL-12-deficient mice showed almost no neurophysiological evidence of EAMG and less reduction in AChR. These results indicate an important role of IL-12 in the induction of an antibody-mediated autoimmune disease, suggest that Th1-dependent complement-fixing IgG2a anti-AChR antibodies are involved in the pathogenesis of EAMG, and help to account for the lack of correlation between anti-AChR levels and clinical disease seen in many earlier studies.

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.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.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.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.

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].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.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.In our CD patients, sensory tricks seem to improve dystonia through an inhibitory effect on motor cortex excitability.

Introduction - The basal ganglia are thought to be involved in the primary dystonias, largely because of the repeated demonstration of neuropathological changes in these nuclei in the secondary dystonias. A hyperactivity of a network involving basal ganglia has been suggested in experimental animal dystonia. To test this hypothesis in humans, we studied the functional correlates of primary cervical dystonia using [ 18 F]FDG and PET. Material and methods - Regional cerebral glucose metabolism (rCMRglc) was measured in 10 patients with idiopathic torticollis (6 drug-free and 4 drug-naive) and in 15 normal controls, using 2-[ 18 F]-fluoro-2-deoxy-D-glucose ([ 18 F]FDG) and positron emission tomography (PET). Results - A significant hypermetabolism in the basal ganglia, thalamus, premotor-motor cortex and cerebellum in the patients compared with normal controls was found. The patients were correctly assigned to their clinical category by a discriminant function analysis with a total accuracy of 96%. Conclusion - The results support the hypothesis that a dysfunction of a subcortical-cortical motor network may play a role in the pathogenesis of focal dystonia, in agreement with the experimental dystonia models.

Cortical reorganization to simple movement in patients with amyotrophic lateral sclerosis (ALS) has been investigated in neuroimaging studies, reporting recruitment of ipsilateral primary sensorimotor (iSMC) and premotor regions (PMd). In order to investigate the spatiotemporal pattern of such overactivation, EEG source analysis to brisk self-paced finger movements was performed in thirty-two ALS patients, able to initiate their movement as fast as controls and clustered according to their most affected motor neuron (upper or lower). Reduced activity within cortical sources in bilateral SMC and caudal mesial areas was found only in patients subgroup with extensive upper motor neuron (UMN) clinical signs and mild motor weakness (U > L). Its absence in patients with opposite clinical features (L > U) suggest that this reduction might represent a possible marker of UMN impairment, and that the lower motor neuron (LMN) degeneration in L > U patients did not exert a retrograde effect over their cortical motor neurons. An ipsilateral premotor recruitment was observed in U > L patients only and since its extent positively correlated with movement initiation speed and right hand Medical Research Council (MRC) score, it might represent a compensatory recruitment. The latter correlation might suggest that the slight motor weakness in those patients may at least partly depend from a UMN dysfunction that can be compensated by cortical recruitment.

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., Fondazione Cariplo, Nicolas G. and Dorothea K. Dumbros Scholarship and Fellowship Fund, United States. Army (contract DAAD-19-02-D-0002), Sixth Framework Programme (European Commission)

Central nervous system (CNS) delivery of anti-inflammatory cytokines, such as interleukin 4 (IL4), holds promise as treatment for multiple sclerosis (MS). We have previously shown that short-term herpes simplex virus type 1-mediated IL4 gene therapy is able to inhibit experimental autoimmune encephalomyelitis (EAE), an animal model of MS, in mice and non-human primates. Here, we show that a single administration of an IL4-expressing helper-dependent adenoviral vector (HD-Ad) into the cerebrospinal fluid (CSF) circulation of immunocompetent mice allows persistent transduction of neuroepithelial cells and long-term (up to 5 months) CNS transgene expression without toxicity. Mice affected by chronic and relapsing EAE display clinical and neurophysiological recovery from the disease once injected with the IL4-expressing HD-Ad vector. The therapeutic effect is due to the ability of IL4 to increase, in inflamed CNS areas, chemokines (CCL1, CCL17 and CCL22) capable of recruiting regulatory T cells (CD4+CD69- CD25+Foxp3+) with suppressant functions. CSF delivery of HD-Ad vectors expressing anti-inflammatory molecules might represent a valuable therapeutic option for CNS inflammatory disorders.

To assess the efficacy of botulinum toxin (BT-A) and additional physiotherapy in subjects affected by progressive multiple sclerosis (MS) with chronic lower limb spasticity. 15 patients able to walk with assistance were consecutively recruited in a open-label study. All patients received a set of intramuscular injections of BT-A performed with EMG-guidance, according to each patient’s individual pattern of spasticity, followed by additional physiotherapy. Each patient was assessed at baseline, 6 and 12 weeks for muscle tone, spasms frequency, leg pain, gait velocity, self-analysis of gait function. 7 patients received a further treatment session after 4 months and were retested after 4 and 8 months. We observed a significant (P

Data from large multicenter clinical trials (PREEMPT) demonstrated efficacy and safety of onabotulinumtoxin A for prophylactic treatment of chronic migraine (CM), prophylactic drug-free patients. This study aimed to confirm the efficacy of onabotulinumtoxin A in CM patients with unsatisfactory chronic polytherapy. 26 CM patients (18 females) taking multiple prophylactic/symptomatic medications entered the study. The overall dose ranged between 155 and 170 U administered in 31–34 sites following PREEMPT protocol, repeated at 12 weeks intervals. Main efficacy variables included number of headache/migraine days and episodes, total cumulative headache hours, MIDAS and HIT-6 scores; all items were assessed at baseline and at the 12th-week and 24th-week follow-up. The following variables showed statistically significant changes at 12th-week time-point: headache/migraine days, moderate/severe headache days, migraine episodes, total cumulative hours of headache; slight, not significant MIDAS and HIT-6 scores’ improvement was observed. All the efficacy indicators further improved at the 24-week follow-up, even though only headache days and >4 h episodes number were significant. Adverse event were uncommon and did not require treatment discontinuation. Treatment with onabotulinumtoxin A reduced frequency and duration of headache, as well as need for drug consumption and was well tolerated in most cases.

Sensory trick (ST), i.e. the improvement of dystonic posture by application of a sensory stimulus, is a typical Cervical Dystonia (CD) feature. Though its exact mechanism is still unknown, cortical sensorimotor integration processes are likely to be involved. Short latency afferent inhibition (SAI), the physiological inhibition of motor evoked potentials (MEP) mediated by somatosensory stimulation, could potentially help to understand this phenomenon. We evaluated by means of SAI whether the inhibitory effect of somatosensory afferent volley is preserved in CD patients; Moreover, we assessed if sensory trick may change SAI profile in patients with CD. We performed SAI at rest and during ST performance in 2 groups of CD patients: group 1 ( n = 13), patients high-responsive to ST and group 2 ( n = 8), patients no- or slightly responsive to ST. Results: We found an overall SAI impairment in both CD groups at rest; rather unexpectedly, SAI was less effective and MEP amplitude increased with ST in group 1, while just slight or no effect was observed in group 2. The physiological inhibition of sensory stimuli over motor cortex, measured with SAI, is decreased in our CD patients. The trick-related dystonia relief seems to occur through a paradoxical enhancement of the sensorimotor circuitry, at least in high-responsive ST patients.

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. (c) 2005 Elsevier Ireland Ltd. All rights reserved. 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. (c) 2005 Elsevier Ireland Ltd. All rights reserved. RI Corti, Angelo/F-7046-2012

Evoked potentials are used in the functional assessment of sensory and motor pathways. Their usefulness in monitoring the evolution of multiple sclerosis has not been fully clarified.The aim of this longitudinal study was to examine the usefulness of multimodal evoked potential in predicting paraclinical outcomes of disease severity and as a prognostic marker in multiple sclerosis.Eighty four patients with clinically definite multiple sclerosis underwent Expanded Disability Status Scale (EDSS) and functional system scoring at study entry and after a mean (standard deviation) follow-up of 30.5 (11.7) months. Sensory and motor evoked potentials were obtained in all patients at study entry and at follow-up in 64 of them, and quantified according to a conventional score.Cross-sectionally, the severity of each evoked potential score significantly correlated with the corresponding functional system (0.32R0.60, p0.01, for all but follow-up visual evoked potential) and with EDSS (0.34R0.61; p0.001 for all but brain stem evoked potential). EDSS significantly correlated with global evoked potential score severity (baseline R = 0.60, follow-up R = 0.46, p0.001). Using longitudinal analysis, only changes in somatosensory evoked potential scores were significantly correlated with changes of sensory functional system (R = 0.34, p = 0.006). However, patients with multiple sclerosis with disability progression at follow-up had more severe baseline evoked potential scores than patients who remained stable. Patients with severe baseline global evoked potential score (higher than the median value) had a risk of 72.5% to progress on disability at follow-up, whereas patients with multiple sclerosis with lower scores had a risk of only 36.3%.These results suggest that evoked potential is a good marker of the severity of nervous damage in multiple sclerosis and may have a predictive value regarding the evolution of disability.

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.

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.

Widespread demyelination and axonal loss are the pathological hallmarks of multiple sclerosis. The multifocal nature of this chronic inflammatory disease of the central nervous system complicates cellular therapy and puts emphasis on both the donor cell origin and the route of cell transplantation. We established syngenic adult neural stem cell cultures and injected them into an animal model of multiple sclerosis--experimental autoimmune encephalomyelitis (EAE) in the mouse--either intravenously or intracerebroventricularly. In both cases, significant numbers of donor cells entered into demyelinating areas of the central nervous system and differentiated into mature brain cells. Within these areas, oligodendrocyte progenitors markedly increased, with many of them being of donor origin and actively remyelinating axons. Furthermore, a significant reduction of astrogliosis and a marked decrease in the extent of demyelination and axonal loss were observed in transplanted animals. The functional impairment caused by EAE was almost abolished in transplanted mice, both clinically and neurophysiologically. Thus, adult neural precursor cells promote multifocal remyelination and functional recovery after intravenous or intrathecal injection in a chronic model of multiple sclerosis.