While the vast majority of Alzheimer's disease (AD) is non-familial, the animal models of AD that are commonly used for studying disease pathogenesis and development of therapy are mostly of a familial form. We aimed to generate a model reminiscent of the etiologies related to the common late-onset Alzheimer's disease (LOAD) sporadic disease that will recapitulate AD/dementia features. Naïve female mice underwent ovariectomy (OVX) to accelerate aging/menopause and were fed a high fat-sugar-salt diet to expose them to factors associated with increased risk of development of dementia/AD. The OVX mice fed a high fat-sugar-salt diet responded by dysregulation of glucose/insulin, lipid, and liver function homeostasis and increased body weight with slightly increased blood pressure. These mice developed AD-brain pathology (amyloid and tangle pathologies), gliosis (increased burden of astrocytes and activated microglia), impaied blood vessel density and neoangiogenesis, with cognitive impairment. Thus, OVX mice fed on a high fat-sugar-salt diet imitate a non-familial sporadic/environmental form of AD/dementia with vascular damage. This model is reminiscent of the etiologies related to the LOAD sporadic disease that represents a high portion of AD patients, with an added value of presenting concomitantly AD and vascular pathology, which is a common condition in dementia. Our model can, thereby, provide a valuable tool for studying disease pathogenesis and for the development of therapeutic approaches.

Background: Mesenchymal stem cells (MSC) were shown to possess immunomodulatory and neurotrophic effects. Our previous trials, have shown that intrathecal (IT) and intravenous (IV) administration of MSCs were safe and provided indications of beneficial clinical effects. Methods: This is an open prospective study to evaluate the safety and the long-term clinical and immunological effects of multiple injections of autologous MSCs in 24 patients with active-progressive MS. At inclusion, the mean age of the patients was 47.0 ± 9.22, and the mean EDSS score was 6.75 ± 0.68 (range: 5.5–7.5). Patients were initially treated with 1 ×10 6 MSCS/kg of body weight (IT + IV) and subsequently with up to additional eight courses of MSCs, at intervals of 6–12 months. The duration of the trial was 4 years. Results: No serious, treatment-related adverse events were observed during the follow-up period. Twenty-two of the 24 patients were either stable or improved at the last follow-up visit. Ten patients had a lower than baseline EDSS at the last follow-up (nine were among those who received >2 treatments and one in the subgroup of ≤ 2 treatments, p = 0.04). The mean EDSS score reduced from 6.75 ± 0.68 at baseline to 6.42 ± 0.84 at the last visit, during a median follow-up period of 27.8 months ( p = 0.028). Immunological follow-up showed a transient upregulation of CD4+CD25+FoxP3+ cells and downregulation of the proliferative ability of lymphocytes. Conclusions: Repeated MSC treatments in patients with progressive MS were shown safe at the short/intermediate term and induced clinical benefits (especially in patients treated with >2 injections) that lasted for up to 4 years, paralleled by short-term immunomodulatory effects. Clinical Trial Registration: www.ClinicalTrials.gov , identifier: NCT04823000.

In this study (trial registration: NCT02166021), we aimed to evaluate the optimal way of administration, the safety and the clinical efficacy of mesenchymal stem cell (MSC) transplantation in patients with active and progressive multiple sclerosis. Forty-eight patients (28 males and 20 females) with progressive multiple sclerosis (Expanded Disability Status Scale: 3.0-6.5, mean : 5.6 ± 0.8, mean age: 47.5 ± 12.3) and evidence of either clinical worsening or activity during the previous year, were enrolled (between 2015 and 2018). Patients were randomized into three groups and treated intrathecally (IT) or intravenously (IV) with autologous MSCs (1 × 106/kg) or sham injections. After 6 months, half of the patients from the MSC-IT and MSC-IV groups were retreated with MSCs, and the other half with sham injections. Patients initially assigned to sham treatment were divided into two subgroups and treated with either MSC-IT or MSC-IV. The study duration was 14 months. No serious treatment-related safety issues were detected. Significantly fewer patients experienced treatment failure in the MSC-IT and MSC-IV groups compared with those in the sham-treated group (6.7%, 9.7%, and 41.9%, respectively, P = 0.0003 and P = 0.0008). During the 1-year follow-up, 58.6% and 40.6% of patients treated with MSC-IT and MSC-IV, respectively, exhibited no evidence of disease activity compared with 9.7% in the sham-treated group (P < 0.0001 and P < 0.0048, respectively). MSC-IT transplantation induced additional benefits on the relapse rate, on the monthly changes of the T2 lesion load on MRI, and on the timed 25-foot walking test, 9-hole peg test, optical coherence tomography, functional MRI and cognitive tests. Treatment with MSCs was well-tolerated in progressive multiple sclerosis and induced short-term beneficial effects regarding the primary end points, especially in the patients with active disease. The intrathecal administration was more efficacious than the intravenous in several parameters of the disease. A phase III trial is warranted to confirm these findings.

The complexity of central nervous system (CNS) degenerative/inflammatory diseases and the lack of substantially effective treatments point to the need for a broader therapeutic approach to target multiple components involved in the disease pathogenesis. We suggest a novel approach directed for the elimination of pathogenic agents from the CNS and, in parallel, its enrichment with an array of neuroprotective substances, using a "cerebrospinal fluid (CSF) exchange" procedure, in which endogenous (pathogenic) CSF is removed and replaced by artificial CSF (aCSF) enriched with secretions of human mesenchymal stem cells (MSCs). MSCs produce a variety of neuroprotective agents and have shown beneficial effects when cells are transplanted in animals and patients with CNS diseases. Our data show that MSCs grown in aCSF secrete neurotrophic factors, anti-inflammatory cytokines, and anti-oxidant agents; moreover, MSC-secretions-enriched-aCSF exerts neuroprotective and immunomodulatory effects in neuronal cell lines and spleen lymphocytes. Treatment of experimental-autoimmune-encephalomyelitis (EAE) mice with this enriched-aCSF using an intracerebroventricular (ICV) CSF exchange procedure ("CSF exchange therapy") caused a significant delay in the onset of EAE and amelioration of the clinical symptoms, paralleled by a reduction in axonal damage and demyelination. These findings point to the therapeutic potential of the CSF exchange therapy using MSC-secretions-enriched-aCSF in inflammatory/degenerative diseases of the CNS.

Tau-immumotherapy has shown promising results in tangle/tauopathy-tg animal models. Here we immunized amyloid-mice (APPSwe/PSEN1dE9-tg, presenting amyloid-plaques, not neurofibrillary-tangles) with phos-tau peptides, previously shown by us to have high efficacy in mutant-tau tauopathy-mice. These amyloid-mice allowed us to test the effect of the vaccine in a model of familial AD patients with mutant amyloid plaque pathology, where tau pathology - once develops - is of non-mutant tau. Fourteen-month-old amyloid-mice were immunized with phos-tau peptides or vehicle. Eight weeks later, amelioration of cognitive impairment was noticed. Histological analysis revealed that the phos (non-mutant)-tau pathology (detected by us in these aged amyloid-mice while not in non-tg-mice), was lower in the phos-tau immunized amyloid-mice than in the non-immunized mice. Interestingly, we detected a decrease in amyloid plaque pathology, probably associated with the increased microglial burden, which surrounded both tau and amyloid pathology. These results point to the added value of immunizing AD-mice with the phos-tau-vaccine, targeting both tau and amyloid pathology, which may have clinical relevance. It also points to the multifaceted interplay between tau/amyloid pathologies.

Background: Plasma-exchange/plasmapheresis (PLEX) is an efficient treatment for several immune mediated diseases. In addition to its known efficacy in myasthenia gravis and Gulliain Barre syndrome, it has been also shown to be effective in certain patients with MS and other CNS demyelinating disorders, during an acute/sub-acute deterioration of the disease. Aims and methods: We report the results of an open prospective study with PLEX in 36 patients with progressive forms of multiple sclerosis (either secondary progressive or relapsing-progressive) and 12 patients with NMO-spectrum disease. All patients had experienced a significant clinical deterioration in the year prior to inclusion (0.5-1 degree or more, in the EDSS scale or a severe relapse from which they did not fully recover) and responded partially or not at all to steroidal treatment. The mean EDSS score at inclusion was 5.91 ± 1.46. The mean EDSS for the MS subgroup was 5.95 ± 1.3 and for the NMO subgroup, 5.6 ± 1.4. The mean duration of the disease was 11.4 ± 7.8 years (12 ± 7.6 for the MS and 5.75 4.59 for the NMO). All patients were treated with 5 courses of PLEX in 2 weeks, followed by a monthly course for one year. Results: Twenty eight of the 48 patients (58.3 %) improved significantly in the EDSS score at year one post initiation of PLEX. The mean EDSS score declined from 5.91 ± 1.46 at inclusion, to 5.41 ± 1.8 at year one. This improvement was more pronounced in the NMO group: Ten out of twelve patients with NMO (83%) improved and their mean EDSS score was reduced from 5.6 ± 1.4 before the treatment to 4.7 ± 1.5 EDSS score post PLEX. In the whole group there were 16 patients with over imposed relapses (relapsing-progressive course) with a total of 26 relapses in the year prior to the inclusion; the number of relapses during the year following PLEX was reduced from 26 to 4. In general patients with prominent myelitic involvement had the most impressive response to the treatment. Five patients suffered from minor infections and one was admitted with sepsis. No other major side effects were observed. Conclusion: PLEX may benefit some patients with progressive MS and NMO and thus may represent an alternative second line treatment modality for such patients with highly active disease, especially those with myelitic forms, and recent deterioration that did not respond to steroids. Larger, controlled studies are warranted to confirm the efficacy of PLEX in these subgroups of MS.

Neuromyelitis optica (NMO) and myasthenia gravis (MG) are autoimmune diseases mediated by autoantibodies against either aquaporin 4 (AQP4) or acetylcholine receptor (AChR), respectively. Recently, we and others have reported an increased prevalence of NMO in patients with MG. To verify whether coexisting autoimmune disease may exacerbate experimental autoimmune MG, we tested whether active immunization with AQP4 peptides or passive transfer of NMO-Ig can affect the severity of EAMG. Injection of either AQP4 peptide or NMO-Ig to EAMG or to naive mice caused increased fatigability and aggravation of EAMG symptoms as expressed by augmented muscle weakness (but not paralysis), decremental response to repetitive nerve stimulation, increased neuromuscular jitter, and aberration of immune responses. Thus, our study shows increased disease severity in EAMG mice following immunization with the NMO autoantigen AQP4 or by NMO-Ig, mediated by augmented inflammatory response. This can explain exacerbation or increased susceptibility of patients with one autoimmune disease to develop additional autoimmune syndrome.

IMPORTANCE Preclinical studies have shown that neurotrophic growth factors (NTFs) extend the survival of motor neurons in amyotrophic lateral sclerosis (ALS) and that the combined delivery of these neurotrophic factors has a strong synergistic effect. We have developed a culture-based method for inducing mesenchymal stem cells (MSCs) to secrete neurotrophic factors. These MSC-NTF cells have been shown to be protective in several animal models of neurodegenerative diseases. OBJECTIVE To determine the safety and possible clinical efficacy of autologous MSC-NTF cells transplantation in patients with ALS. DESIGN, SETTING, AND PARTICIPANTS In these open-label proof-of-concept studies, patients with ALS were enrolled between June 2011 and October 2014 at the Hadassah Medical Center in Jerusalem, Israel. All patients were followed up for 3 months before transplantation and 6 months after transplantation. In the phase 1/2 part of the trial, 6 patients with early-stage ALS were injected intramuscularly (IM) and 6 patients with more advanced disease were transplanted intrathecally (IT). In the second stage, a phase 2a dose-escalating study, 14 patients with early-stage ALS received a combined IM and IT transplantation of autologous MSC-NTF cells. INTERVENTIONS Patients were administered a single dose of MSC-NTF cells. MAIN OUTCOMES AND MEASURES The primary end points of the studies were safety and tolerability of this cell therapy. Secondary end points included the effects of the treatment on various clinical parameters, such as the ALS Functional Rating Scale-Revised score and the respiratory function. RESULTS Among the 12 patients in the phase 1/2 trial and the 14 patients in the phase 2a trial aged 20 and 75 years, the treatment was found to be safe and well tolerated over the study follow-up period. Most of the adverse effects were mild and transient, not including any treatment-related serious adverse event. The rate of progression of the forced vital capacity and of the ALS Functional Rating Scale-Revised score in the IT (or IT+IM)-treated patients was reduced (from -5.1% to -1.2%/month percentage predicted forced vital capacity, P < .04 and from -1.2 to 0.6 ALS Functional Rating Scale-Revised points/month, P = .052) during the 6 months following MSC-NTF cell transplantation vs the pretreatment period. Of these patients, 13 (87%) were defined as responders to either ALS Functional Rating Scale-Revised or forced vital capacity, having at least 25% improvement at 6 months after treatment in the slope of progression. CONCLUSIONS AND RELEVANCE The results suggest that IT and IM administration of MSC-NTF cells in patients with ALS is safe and provide indications of possible clinical benefits, to be confirmed in upcoming clinical trials. TRIAL REGISTRATION clinicaltrials.gov Identifiers: NCT01051882 and NCT01777646.

This chapter reviews the clinical and pathophysiological features of systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and Sjögren's syndrome (SS) in turn, with a focus on neurological manifestations. It also discusses the treatment of SLE, RA, and SS. Neurological and psychiatric symptoms occur in many patients and may reflect damage to various components of the nervous system from the cerebral cortex to the muscle, although the central nervous system (CNS) is usually affected more often than the peripheral nervous system. Structural derangement of the cervical spine predisposes to cervical myelopathy and in rare instances the lower cranial nerves, brainstem, and posterior circulation may be distorted by atlantoaxial dislocation. Neurologists should be aware of the potential for neurological side effects of many of the drugs used in these conditions, and the possibility for conditions occurring due to immune compromise, such as opportunistic infections and malignancy.

Background: Neuromyelitis optica (NMO) is a chronic autoimmune disease of the central nervous system (CNS). The main immunological feature of the disease is the presence of autoantibodies to Aquaporin 4 (AQP4+), identified in about 82 % of cases. Currently, there are no reliable biomarkers for monitoring treatment response in patients with NMO. In an effort to identify biomarkers, we analyzed microRNAs (miRNAs) in the blood of rituximab-treated NMO patients before and after therapy.Methods: Total RNA extracted from whole blood of nine rituximab-responsive NMO patients before and 6 months following treatment was subjected to small RNAseq analysis. The study included an additional group of seven untreated AQP4+ seropositive NMO patients and 15 healthy controls (HCs).Results: Fourteen miRNAs were up regulated and 32 were downregulated significantly in the blood of NMO patients following effective therapy with rituximab (all p < 0.05). Furthermore, we show that expression of 17 miRNAs was significantly higher and of 25 miRNAs was significantly lower in untreated NMO patients compared with HCs (all p < 0.05). Following rituximab treatment, the expression levels of 10 of the 17 miRNAs that show increased expression in NMO reverted to the levels seen in HCs. Six of these "normalized" miRNAs are known as brain-specific/enriched miRNAs.Conclusions: Specific miRNA signatures in whole blood of patients with NMO might serve as biomarkers for therapy response. Furthermore, monitoring the levels of brain-specific/enriched miRNAs in the blood might reflect the degree of disease activity in the CNS of inflammatory demyelinating disorders.

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system and is associated with demyelination, neurodegeneration, and sensitivity to oxidative stress. In this work, we administered a nanodroplet formulation of pomegranate seed oil (PSO), denominated Nano-PSO, to mice induced for experimental autoimmune encephalomyelitis (EAE), an established model of MS. PSO comprises high levels of punicic acid, a unique polyunsaturated fatty acid considered as one of the strongest natural antioxidants. We show here that while EAE-induced mice treated with natural PSO presented some reduction in disease burden, this beneficial effect increased significantly when EAE mice were treated with Nano-PSO of specific size nanodroplets at much lower concentrations of the oil. Pathological examinations revealed that Nano-PSO administration dramatically reduced demyelination and oxidation of lipids in the brains of the affected animals, which are hallmarks of this severe neurological disease. We propose that novel formulations of natural antioxidants such as Nano-PSO may be considered for the treatment of patients suffering from demyelinating diseases. On the mechanistic side, our results demonstrate that lipid oxidation may be a seminal feature in both demyelination and neurodegeneration.

Adult polyglucosan body disease (APBD) is a rare glycogenosis manifesting progressive spastic paraparesis, sensorimotor polyneuropathy and neurogenic bladder. Misdiagnosis of APBD may lead to unnecessary investigations and to potentially harmful therapeutic interventions. To examine the frequency of misdiagnosis of APBD, we retrospectively reviewed the clinical data of 30 patients diagnosed between 1991 and 2013. Diagnosis was based on the combination of typical clinical and imaging findings, reduced glycogen branching enzyme activity, and the presence of p.Y326S GBE1 mutation. Initial symptoms started in the 5th–6th decade with bladder dysfunction (47 %), gait problems (33 %) or both. Diagnosis of APBD was delayed by 6.8 (±4.8) years. Consistent signs at diagnosis were spasticity in the legs (93 %), decreased or absent ankle reflexes (100 %), bilateral extensor plantar response (100 %) and distal sensory deficit (80 %). Nerve conduction study showed invariable sensorimotor polyneuropathy, and MRI demonstrated cervical spinal cord atrophy (100 %) and leukoencephalopathy (97 %). All 30 patients were initially misdiagnosed. Common misdiagnoses included cerebral small vessel disease (27 %), multiple sclerosis (17 %), amyotrophic lateral sclerosis (17 %) and peripheral neuropathies (20 %). Consequently, 27 % received inappropriate therapy. In addition, lower urinary tract symptoms in 60 % of men were attributed solely to prostatic disorders but did not respond to medical treatment or prostatectomy. These findings suggest that despite limited clinical variability, APBD is invariably misdiagnosed and patients are often mistreated. Physicians’ unfamiliarity with the typical clinical and imaging features of APBD appears as the main reason for misdiagnosis.

A 75-year-old man was referred to the Hadassah Medical Center with a 6-month history of progressive limb weakness, dysarthria, and cognitive deterioration. His past medical history included prostate hyperplasia, hypothyroidism, diabetes mellitus, cardiac arrhythmias controlled by pacemaker implantation (1997), and hypertension. Autoimmune myasthenia gravis (MG) had been diagnosed 2 years earlier, based on symptoms of fluctuating fatigue, dysarthric speech, eyelid ptosis, and seropositivity for muscle acetylcholine receptor (AChR) binding antibody. MRI did not reveal thymic enlargement, and malignancy markers (and whole-body computed tomography) were negative. Moderate improvement followed treatment, initially with intravenous immune globulin and later with low dose corticosteroids, pyridostigmine, and azathioprine. The patient was evaluated previously at the Mayo Clinic (Rochester, Minnesota) and had been diagnosed with amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). The diagnosis was based on the cognitive exam and clinical features of progressive diffuse upper and lower motor neuron dysfunction with electromyographic findings (low motor amplitudes, no focal slowing or conduction blocks, no postexercise facilitation, presence of diffuse fibrillation and fasciculation potentials, and large complex motor unit potentials in all limbs) fulfilling the El-Escorial criteria for ALS.1 MRI and positron emission tomography scans of the brain showed moderate atrophy predominantly affecting the frontal and temporal lobes. Spinal fluid was acellular with slightly elevated total protein (50 mg%). Autoimmune serology revealed antibodies specific for muscle (AChR binding 9.47 nmol/L [normal 0.00–0.02]; AChR modulating 100% loss [normal 0–20%]; striational 15,360 [normal <60]) and thyroglobulin, and anti-nuclear antibody. On admission, the patient had memory impairment and signs of frontotemporal functional deficits, typical of FTD. Dysarthria rendered speech totally incomprehensible. He had mild eyelid ptosis bilaterally (without extra-ocular muscle weakness or diplopia) and was markedly quadriparetic (confined to wheelchair) with bilateral foot drop. Distal hand and foot muscles were moderately atrophic, and fasciculations were prominent in all limbs. Deep tendon reflexes were brisk in arms and legs (except hypoactive Achilles reflexes), and an extensor plantar response was evoked bilaterally. Superficial sensation was normal, and vibration sense was reduced slightly distally in the legs. Due to the diagnosis of MG, the patient did not meet inclusion criteria for the Hadassah clinical trial in ALS with autologous enhanced mesenchymal stem cells (MSC-NTF, Brainstorm®, Petach Tikva; NCT01051882).2-4 The Hadassah Ethics Committee issued a special license for treatment on a compassionate basis. MSC-NTF (prepared from the patient's bone marrow) were injected intrathecally (1.5 × 106 per kilogram of body weight) and at 24 sites along the biceps and triceps muscles of the right arm (1.5 × 106 per site). The intrathecal and intramuscular administration of the cells were chosen based on previous animal and clinical studies from our groups, which showed good migration of the intrathecally injected cells to the CNS4, 5 and amelioration of the "dying-back" phenomenon by intramuscularly injected MSC in early stages of ALS in the SOD mouse model (unpublished data and Dadon-Nachum et al.).6 For the next 2 days the patient had a low-grade fever, headache, and was more confused, but at discharge, these problems had completely subsided. Treatment with azathioprine (125 mg/day) was discontinued 1 month before the injection and re-administered 30 days after the treatment. Pyridostigmine (60 mg 3 times daily) and low dose oral prednisolone (10 mg/day) were continued. At 1 month after transplantation, the patient and his family reported significant improvement in cognition, speech, and muscle power. He was able to walk at least 20 meters without any support. The dysarthria improved to the extent he was able to clearly deliver a speech to an audience. ALS Functional Score Scale-Revised (ALSFRS-R, performed at all time points by the same evaluator and confirmed by a second senior examiner) score rose from 36 to 44, and respiratory forced vital capacity (FVC) and cognitive function also improved significantly (Supplementary Table 1, which is available online, and Fig. 1). At 5 months posttransplantation, due to progression of weakness and deterioration in cognition, a repeat injection of MSC-NTF, was performed. Adverse events following the second treatment included a transient confusional state, moderate fever, and a urinary tract infection. These symptoms subsided completely 3 days posttransplantation, and on his last examination 2 months after the second transplantation, all neurological functions had improved significantly. ALSFRS-R rose from 30 to 43, the quantitative MG score declined from 19 to 14, muscle power improved significantly, foot drop resolved partially, and the FVC increased (Supplementary Table 1). There was no detectable decrement in repetitive nerve stimulation (similarly to his pretransplantation test), but compound muscle action potentials (CMAPs) increased three-fold in the right arm. The co-existence of ALS with MG is extremely rare.7-9 The onset of motor neuronopathy in our patient was accompanied by FTD and was preceded 2 years earlier by muscle weakness, attributed to MG. The patient's background of autoimmunity also included thyroiditis and the presence of anti-nuclear antibodies. It is conceivable in this context that the motor neuronopathy and dementia could have had an autoimmune basis. This suggestion is supported by the modestly elevated cerebrospinal fluid protein level10 (potentially attributable to his diabetes or intravenous immunoglobulin treatment) and the profile of organ-specific autoantibodies (including muscle AChR and striational antibody values commonly encountered with paraneoplastic neurological autoimmunity).11 No cancer was found or imaged. Stem cell therapy has been proposed and tried by others and us in various neurological diseases as a novel means for regeneration and neuroprotection.4, 12-15 Mesenchymal stem cells (MSC) are a particular contemporary focus of clinical research as a potential therapeutic agent due to their safety profile and the relative ease of isolation, culture, and expansion from bone marrow, even from adult patients with neurological disease. They appear to exert both immunomodulatory and neurotrophic/neuroprotective effects4, 5, 16-21 and pose less risk for malignant transformation than embryonic stem cells. The outcomes of small pilot studies of therapy with MSC suggest a neurological stabilization in patients with ALS,4, 13-15 neuroregeneration of the optic tracts in at least 1 trial in progressive multiple sclerosis,12 and beneficial clinical effects in multiple system atrophy.22 The course of the 2 neurological diseases in our patient and the response to the repeated treatments with MSC-NTF provide some unique observations. First, both cognitive and motor disabilities improved after the initial course of cell therapy; these benefits were reversed over the following months. The outcome of the second transplantation was even more remarkable, suggesting that repeated transplantation might be needed to maintain and enhance the clinical benefits of stem cell therapies in neurological diseases. The possibility of an evaluating physician treatment bias or "placebo effect" (although low in such severe degenerative diseases as ALS and contradicted by the electrophysiological and respiratory tests) cannot be excluded totally in such open studies. Second, the improvement in many parameters of the ALSFRS-R and the right arm CMAP (the site of MSC-NTF injection), advocate in favor of motor nerve function being more significantly affected by the treatment (than MG) and may indicate a neurotrophic effect. Laboratory and clinical improvements of this magnitude are not anticipated and are highly unusual in the natural course of ALS. Whether these beneficial effects were induced by transplantation of MSC-NTF cannot be proven, nor whether the neurological improvement was mediated by immunomodulating or neurotrophic effects or by promotion of neuroregeneration. The latter seems less likely, because improvement was evident early after transplantation, before neuronal repair or regeneration might be anticipated. If one assumes that the motor neuron dysfuntion in our patient was due to ALS, rather than an immune-mediated process, the fact that the myasthenic manifestations benefitted less from the cell therapy favors a neurotrophic rather than an immunomodulatory basis for the observed clinical improvements. If the myasthenia, motor neuronopathy and dementia all had an autoimmune basis, one could conclude that the benefit of cell therapy was attributable to the known immunomodulating properties of MSC.17, 19 Additional data from our ongoing clinical trial in 24 patients with ALS will provide more concrete answers to the open questions and may reveal the mechanisms of action of MSC in neurodegenerative diseases such as ALS. Panayiota Petrou, MD1 Avizohar Argov, MD1 Vanda A. Lennon, MD, PhD2 Marc Gotkine, MBBS1 Ibrahim Kassis, PhD1 Adi Vaknin-Dembinsky, MD, PhD1 Tamir Ben-Hur, MD, PhD1 Daniel Offen, PhD3 Oded Abramsky, MD, PhD1 Eldad Melamed, MD4 Dimitrios Karussis, MD, PhD1 1Hadassah University Hospital, Laboratory of Neuroimmunology, Hadassah, Ein-Kerem, Jerusalem, IL-91120, Israel 2Departments of Laboratory Medicine and Pathology, Neurology and Immunology, Mayo Clinic, Rochester, Minnesota, USA 3Felsenstein Medical Research Center, Tel Aviv University, Israel 4Rabin Medical Center, Tel Aviv University, Israel Additional Supporting Information may be found in the online version of this article. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

When studying a rare or orphan disease, we hope to shed light on more prevalent syndromes. Neuromyelitis optica (NMO), also known as Devic's disease, is a rare disease with a prevalence of about 4 in 100,000. Since 2005 when the anti-Aquaporin 4 (AQP4) NMO autoantibody was discovered by Lennon's group at the Mayo clinic, an enormous amount of data have been acquired on the pathogenesis of the disease. A review of the literature showed 47 relevant publications in 2004, compared with 353 in 2013. The auto-antigen AQP4 is expressed on the astrocytic foot processes suggesting a role for astrocytes in the pathogenesis of the disease. However, the astrocytes might play a more active role than has previously been suggested in the immune cascade of NMO pathology. Here we will review epidemiological, clinical diagnostic and therapeutic aspects of NMO and highlight the possible role of astrocytes as major direct and indirect players in the pathogenesis of NMO and related CNS inflammatory diseases.

Tumefactive demyelination (TD) is a solitary cerebral demyelinating lesion clinically and radiologically mimicking brain tumors. It can occur in isolation or may be rarely associated with other demyelinating diseases. The underlying pathogenic mechanisms are unknown. We present the first report of TD following in-vitro fertilization (IVF) in a 36-year-old healthy woman who developed subacute right hemiparesis shortly after a scheduled IVF cycle. Evaluation revealed left hemispheric space-occupying lesion pathologically diagnosed as TD. Treatment with intravenous methylprednisolone promptly resulted in a clinical and radiological improvement maintained thereafter. This report confirms and expands the spectrum of inflammatory demyelinating conditions associated with IVF and suggests possible hormonal influence in the development of TD.

Action myoclonus renal failure (AMRF) syndrome is a rare form of progressive myoclonus epilepsy with renal dysfunction related to mutations in the SCARB2 gene. This gene is involved in lysosomal mannose-6-phosphate-independent trafficking of β-glucocerebrosidase (GC), an enzyme deficient in Gaucher disease. We report a family with myoclonic epilepsy, ataxia and skeletal muscle atrophy but without cognitive impairment or overt renal disease. A novel SCARB2 mutation was indicated by a striking discrepancy between lymphocyte and fibroblast GC activity in the proband evaluated for possible Gaucher disease. Our findings expand the genetic and phenotypic diversity of AMRF and suggest that low GC activity may present an important biochemical clue to the diagnosis of AMRF.

IMPORTANCE Hereditary spastic paraplegia is a highly heterogeneous group of neurogenetic disorders with pure and complicated clinical phenotypes. No treatment is available for these disorders. We identified 2 unrelated families, each with 2 siblings with severe methylenetetrahydrofolate reductase (MTHFR) deficiency manifesting a complicated form of adult-onset hereditary spastic paraparesis partially responsive to betaine therapy.OBSERVATIONS Both pairs of siblings presented with a similar combination of progressive spastic paraparesis and polyneuropathy, variably associated with behavioral changes, cognitive impairment, psychosis, seizures, and leukoencephalopathy, beginning between the ages of 29 and 50 years. By the time of diagnosis a decade later, 3 patients were ambulatory and 1 was bedridden. Investigations have revealed severe hyperhomocysteinemia and hypomethioninemia, reduced fibroblast MTHFR enzymatic activity (18%-52% of control participants), and 3 novel pathogenic MTHFR mutations, 2 as compound heterozygotes in one family and 1 as a homozygous mutation in the other family. Treatment with betaine produced a rapid decline of homocysteine by 50% to 70% in all 4 patients and. over 9 to 15 years, improved the conditions of the 3 ambulatory patients.CONCLUSIONS AND RELEVANCE Although severe MTHFR deficiency is a rare cause of complicated spastic paraparesis in adults, it should be considered in select patients because of the potential therapeutic benefit of betaine supplementation.