Mechanisms and treatment strategies of demyelinating and dysmyelinating Charcot-Marie-Tooth disease

Schwann cells,the myelinating glia of the peripheral nervous system,wrap axons multiple times to build their myelin sheath.Myelin is of paramount importance for axonal integrity and fast axon potential propagation.However,myelin is lacking or dysfunctional in several neuropathies including demyelinating and dysmyelinating Charcot-M arie-To oth disease.Charcot-Marie-To oth disease represents the most prevalent inherited neuropathy in humans and is classified either as axonal,demyelinating or dysmyelinating,or as intermediate.The demyelinating or dysmyelinating forms of Charcot-Marie-Tooth disease constitute the majority of the disease cases and are most frequently due to mutations in the three following myelin genes:peripheral myelin protein 22,myelin protein ze ro and gap junction beta 1(coding for Connexin 32) causing Charcot-M arie-Tooth disease type 1A,Charcot-Marie-Tooth disease type 1B,and X-linked Charcot-M arie-Tooth disease type 1,respectively.The resulting perturbation of myelin structure and function leads to axonal demyelination or dysmyelination and causes severe disabilities in affected patients.No treatment to cure or slow down the disease progression is currently available on the market,howeve r,scientific discoveries led to a better understanding of the pathomechanisms of the disease and to potential treatment strategies.In this review,we describe the features and molecular mechanisms of the three main demyelinating or dysmyelinating forms of Charcot-Marie-Tooth disease,the rodent models used in research,and the emerging therapeutic approaches to cure or counteract the progression of the disease.

X-linked Charcot-Marie-Tooth disease after SARS-CoV-2 vaccination mimicked stroke-like episodes: A case report

BACKGROUND Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) vaccinations have been administered worldwide, with occasional reports of associated neurological complications. Specifically, the impact of vaccinations on individuals with Xlinked Charcot-Marie-Tooth disease type 1(CMTX1) is unclear. Patients with CMTX1 can have stroke-like episodes with posterior reversible encephalopathy syndrome on magnetic resonance imaging(MRI), although this is rare.CASE SUMMARY A 39-year-old man was admitted with episodic aphasia and dysphagia for 2 d. He received SARS-CoV-2 vaccination 39 d before admission. Physical examination showed pes cavus and reduced tendon reflexes. Brain MRI showed bilateral, symmetrical, restricted diffusion with T2 hyperintensities in the cerebral hemispheres. Nerve conduction studies revealed peripheral nerve damage. He was diagnosed with Charcot-Marie-Tooth disease, and a hemizygous mutation in the GJB1 gene on the X chromosome, known to be pathogenic for CMTX1, was identified. Initially, we suspected transient ischemic attack or demyelinating leukoencephalopathy. We initiated treatment with antithrombotic therapy and immunotherapy. At 1.5 mo after discharge, brain MRI showed complete resolution of lesions, with no recurrence.CONCLUSION SARS-CoV-2 vaccination could be a predisposing factor for CMTX1 and trigger a sudden presentation.

Clinical classification and gene mutation of Chinese probands with Charcot-Marie-Tooth disease Analysis of 57 cases

Charcot-Marie-Tooth （CMT） disease is the most common inherited peripheral neuropathic disorder. CMT is clinically and genetically heterogeneous. To date, 27 genes associated with the disease have been cloned. The present study carried out clinical classification according to clinical, electrophysiological and pathological features, conducted inheritance classification according to inheritance patterns, and performed mutation analysis of 13 CMT disease genes （PMP22, CX32, HSPB1, MNF2, MPZ, HSPB8, GDAP1, NFL, EGR2, SIMPLE, RAB7, LMNA, MTMR2） in 57 Chinese probands with CMT. Five cases of AD-CMT1 and 13 cases of sporadic CMT1 were diagnosed as CMT1A; five cases of X-CMT1, one case of X-CMT2 and one case of sporadic CMT1 were diagnosed as CMTXl; four cases of AD-CMT2 were diagnosed as CMT2F; one case of AD-CMT2 and one case of sporadic CMT2 were diagnosed as CMT2A2; one case of AD-CMT2 was diagnosed as CMT2L; one case of AD-CMT2 was diagnosed as CMT2J; one case of AR-CMT1 was diagnosed as CMT4A. Among the 57 CMT probands, seven genotypes were determined among 34 patients, with a detection rate of 59.6%. The results indicated that the clinical classification and inheritance classification are indispensable for selecting potential disease genes for mutation detection, and for efficient molecular diagnosis.

Rapid genetic screening of Charcot-Marie-Tooth disease type 1A and hereditary neuropathy with liability to pressure palsies patients

We used the allele-specific PCR-double digestion method on peripheral myelin protein 22 （PMP22） to determine duplication and deletion mutations in the proband and family members of one family with Charcot-Marie-Tooth disease type 1 and one family with hereditary neuropathy with liability to pressure palsies. The proband and one subclinical family member from the Charcot-Marie-Tooth disease type 1 family had a PMP22 gene duplication; one patient from the hereditary neuropathy with liability to pressure palsies family had a PMP22 gene deletion. Electron microscopic analysis of ultrathin sections of the superficial peroneal nerve from the two probands demonstrated demyelination and myelin sheath hyperplasia, as well as an ＇onion-like＇ structure in the Charcot-Marie-Tooth disease type 1A patient. We observed an irregular thickened myelin sheath and ＇mouse-nibbled＇-Iike changes in the patient with hereditary neuropathy with liability to pressure palsies. In the Charcot-Marie-Tooth disease type 1A patient, nerve electrophysiological examination revealed moderate-to-severe reductions in the motor and sensory conduction velocities of the bilateral median nerve, ulnar nerve, tibial nerve, and sural nerve. Moreover, the compound muscle action potential amplitude was decreased. In the patient with hereditary neuropathy with liability to pressure palsies, the nerve conduction velocity of the bilateral tibial nerve and sural nerve was moderately reduced, and the nerve conduction velocity of the median nerve and ulnar nerve of both upper extremities was slightly reduced.

Anatomical distributional defects in mutant genes associated with dominant intermediate Charcot-Marie-Tooth disease type C in an adenovirus-mediated mouse model

Dominant intermediate Charcot-Marie-Tooth disease type C（DI-CMTC） is a dominantly inherited neuropathy that has been classified primarily based on motor conduction velocity tests but is now known to involve axonal and demyelination features.DI-CMTC is linked to tyrosyl-t RNA synthetase（YARS）-associated neuropathies,which are caused by E196 K and G41 R missense mutations and a single de novo deletion（153-156 del VKQV）.It is well-established that these YARS mutations induce neuronal dysfunction,morphological symptoms involving axonal degeneration,and impaired motor performance.The present study is the first to describe a novel mouse model of YARS-mutation-induced neuropathy involving a neuron-specific promoter with a deleted mitochondrial targeting sequence that inhibits the expression of YARS protein in the mitochondria.An adenovirus vector system and in vivo techniques were utilized to express YARS fusion proteins with a Flag-tag in the spinal cord,peripheral axons,and dorsal root ganglia.Following transfection of YARS-expressing viruses,the distributions of wild-type（WT） YARS and E196 K mutant proteins were compared in all expressed regions; G41 R was not expressed.The proportion of Flag/green fluorescent protein（GFP） double-positive signaling in the E196 K mutant-type mice did not significantly differ from that of WT mice in dorsal root ganglion neurons.All adenovirus genes,and even the empty vector without the YARS gene,exhibited GFP-positive signaling in the ventral horn of the spinal cord because GFP in an adenovirus vector is driven by a cytomegalovirus promoter.The present study demonstrated that anatomical differences in tissue can lead to dissimilar expressions of YARS genes.Thus,use of this novel animal model will provide data regarding distributional defects between mutant and WT genes in neurons,the DICMTC phenotype,and potential treatment approaches for this disease.

Advances in the molecular diagnosis of Charcot-Marie-Tooth disease

Charcot-Marie-Tooth(CMT) disease or hereditary motor and sensory neuropathy is the most common inherited neuromuscular disorder affecting at least 1 in 2500. CMT disease is pathologically and genetically heterogeneous and is characterized by a variable age of onset, slowly progressive weakness and muscle atrophy, starting in the lower limbs and subsequently affecting the upper extremities. Symptoms are usually slowly progressive, especially for the classic and late-onset phenotypes, but can be rather severe in early-onset forms. CMT is grouped into demyelinating, axonal and intermediate forms, based on electrophysiological and pathological findings. The demyelinating types are characterized by severely reduced motor nerve conduction velocities(MNCVs) and mainly by myelin abnormalities. The axonal types are characterized by normal or slightly reduced MNCVs and mainly axonal abnormalities. The intermediate types are characterized by MNCVs between 25 m/s and 45 m/s and they have features of both demyelination and axonopathy. Inheritance can be autosomal dominant, X-linked, or autosomal recessive. Mutations in more than 30 genes have been associated with the different forms of CMT, leading to majoradvancements in molecular diagnostics of the disease, as well as in the understanding of pathogenetic mechanisms. This editorial aims to provide an account that is practicable and efficient on the current molecular diagnostic procedures for CMT, in correlation with the clinical, pathological and electrophysiological findings. The most frequent causative mutations of CMT will also be outlined.

The Role of Orthotic Service in Modern Rehabilitation of Patients with Charcot-Marie-Tooth Disease

Charcot-Marie-Tooth (CMT) disease, which encompasses several hereditary motor and sensory neuropathies, is one of the most common neuro-muscular disorders. 80% of patients having CMT disease are diagnosed with per cavus deformity. Orthosis is widespread and varies widely in forms. The paper arises the necessity of habilitation at the earliest possible stage as only a few patients use it. The meta-analysis of 412 scientific papers concerning this problem demonstrates the getting better gate, balance and the stopping CMT progression which is scientifically proven. It is also shown that patients with CMT use low prevalence of orthotics, and demonstrate low compliance of patients (for various reasons), high expectations from this habilitation technique.

Subarachnoid and Peripheral Nerve Block in a Patient with Charcot-Marie-Tooth Disease

Charcot-Marie-Tooth disease (CMT) is a hereditary peripheral neuropathy characterized by progressive distal muscle weakness and wasting. If conservative treatment fails, or is not appropriately initiated, deformity, immobility and chronic pain may result. In severe cases, surgical intervention may be required. With the exception of case reports and case series, limited safety and efficacy data exists regarding the use of neuraxial and regional anesthesia for patients with CMT. This paper describes an anesthetic case report of a patient with CMT, and also provides a review of general and regional anesthetic considerations for this cohort. The purpose of this report is to highlight the potential benefits of neuraxial and regional anesthesia in patients with neuromuscular disorders, especially in settings where intra- and post-operative resources may be limited.

Drosophila models used to simulate human ATP1A1 gene mutations that cause Charcot-Marie-Tooth type 2 disease and refractory seizures

Certain amino acids changes in the human Na^(+)/K^(+)-ATPase pump,ATPase Na^(+)/K^(+)transporting subunit alpha 1(ATP1A1),cause Charcot-Marie-Tooth disease type 2(CMT2)disease and refractory seizures.To develop in vivo models to study the role of Na^(+)/K^(+)-ATPase in these diseases,we modified the Drosophila gene homolog,Atpα,to mimic the human ATP1A1 gene mutations that cause CMT2.Mutations located within the helical linker region of human ATP1A1(I592T,A597T,P600T,and D601F)were simultaneously introduced into endogenous Drosophila Atpαby CRISPR/Cas9-mediated genome editing,generating the Atpα^(TTTF)model.In addition,the same strategy was used to generate the corresponding single point mutations in flies(Atpα^(I571T),Atpα^(A576T),Atpα^(P579T),and Atpα^(D580F)).Moreover,a deletion mutation(Atpα^(mut))that causes premature termination of translation was generated as a positive control.Of these alleles,we found two that could be maintained as homozygotes(Atpα^(I571T)and Atpα^(P579T)).Three alleles(Atpα^(A576T),Atpα^(P579)and Atpα^(D580F))can form heterozygotes with the Atpαmut allele.We found that the Atpαallele carrying these CMT2-associated mutations showed differential phenotypes in Drosophila.Flies heterozygous for Atpα^(TTTF)mutations have motor performance defects,a reduced lifespan,seizures,and an abnormal neuronal morphology.These Drosophila models will provide a new platform for studying the function and regulation of the sodium-potassium pump.

Surgical Treatment of Scoliosis in Patients with Charcot-Marie-Tooth Disease

Objective:Apparently, scoliosis occurs in approximately one-third of patients with Charcot-Marie-Tooth disease. Little is known about the response of these curves to treatment. The purpose of this study was to evaluate the results of spinal surgery in these peculiar patients. Methods: We retrospectively evaluated the results of spinal surgery in eight patients who had scoliosis due to clinically and electrophysiologically proven Charcot-Marie-Tooth disease. Radiographs were reviewed. The location and direction of the curve pattern, the age at the time of surgery, type of surgery, number of levels fused, instrumentations used, intra or postoperative complications, and results and need for reoperation were recorded. Results: Eight patients associated with Charcot-Marie-Tooth disease who underwent scoliotic surgery were identified. The average age and curve at the time of surgery were 21.1 years and 56.4° respectively. 62.5% of the curves had left thoracic component and more than one third was associated with thoracic hyperkyphosis. Long posterior spinal fusion was performed most often, with an average of 11.5 spinal segments fused. Instrumentation was used in all posterior fusions. At an average of 39 months (range, 24 to 72 months) postoperatively, the fusion appeared to be solid in all patients. Conclusion: Scoliosis in patients with Charcot-Marie-Tooth disease differs from that in patients with idiopathic scoliosis in regarding to the etiology and the prevalence of thoracic hyperkyphosis, but the surgical management appears to be similar. Spondylodesis does not appear to be associated with a high rate of complications.

Microglial response to aging and neuroinflammation in the development of neurodegenerative diseases

Cellular senescence and chronic inflammation in response to aging are considered to be indicators of brain aging;they have a great impact on the aging process and are the main risk factors for neurodegeneration.Reviewing the microglial response to aging and neuroinflammation in neurodegenerative diseases will help understand the importance of microglia in neurodegenerative diseases.This review describes the origin and function of microglia and focuses on the role of different states of the microglial response to aging and chronic inflammation on the occurrence and development of neurodegenerative diseases,including Alzheimer's disease,Huntington's chorea,and Parkinson's disease.This review also describes the potential benefits of treating neurodegenerative diseases by modulating changes in microglial states.Therefore,inducing a shift from the neurotoxic to neuroprotective microglial state in neurodegenerative diseases induced by aging and chronic inflammation holds promise for the treatment of neurodegenerative diseases in the future.

The role of exosomes in adult neurogenesis:implications for neurodegenerative diseases

Exosomes are cup-shaped extracellular vesicles with a lipid bilayer that is approximately 30 to 200 nm in thickness.Exosomes are widely distributed in a range of body fluids,including urine,blood,milk,and saliva.Exosomes exert biological function by transporting factors between different cells and by regulating biological pathways in recipient cells.As an important form of intercellular communication,exosomes are increasingly being investigated due to their ability to transfer bioactive molecules such as lipids,proteins,mRNAs,and microRNAs between cells,and because they can regulate physiological and pathological processes in the central nervous system.Adult neurogenesis is a multistage process by which new neurons are generated and migrate to be integrated into existing neuronal circuits.In the adult brain,neurogenesis is mainly localized in two specialized niches:the subventricular zone adjacent to the lateral ventricles and the subgranular zone of the dentate gyrus.An increasing body of evidence indicates that adult neurogenesis is tightly controlled by environmental conditions with the niches.In recent studies,exosomes released from different sources of cells were shown to play an active role in regulating neurogenesis both in vitro and in vivo,thereby participating in the progression of neurodegenerative disorders in patients and in various disease models.Here,we provide a state-of-the-art synopsis of existing research that aimed to identify the diverse components of exosome cargoes and elucidate the therapeutic potential of exosomal contents in the regulation of neurogenesis in several neurodegenerative diseases.We emphasize that exosomal cargoes could serve as a potential biomarker to monitor functional neurogenesis in adults.In addition,exosomes can also be considered as a novel therapeutic approach to treat various neurodegenerative disorders by improving endogenous neurogenesis to mitigate neuronal loss in the central nervous system.

Unraveling the gut-brain axis:the impact of steroid hormones and nutrition on Parkinson's disease

This comprehensive review explores the intricate relationship between nutrition,the gut microbiome,steroid hormones,and Parkinson's disease within the context of the gut-brain axis.The gut-brain axis plays a pivotal role in neurodegenerative diseases like Parkinson's disease,encompassing diverse components such as the gut microbiota,immune system,metabolism,and neural pathways.The gut microbiome,profoundly influenced by dietary factors,emerges as a key player.Nutrition during the first 1000 days of life shapes the gut microbiota composition,influencing immune responses and impacting both child development and adult health.High-fat,high-sugar diets can disrupt this delicate balance,contributing to inflammation and immune dysfunction.Exploring nutritional strategies,the Mediterranean diet's anti-inflammatory and antioxidant properties show promise in reducing Parkinson's disease risk.Microbiome-targeted dietary approaches and the ketogenic diet hold the potential in improving brain disorders.Beyond nutrition,emerging research uncovers potential interactions between steroid hormones,nutrition,and Parkinson's disease.Progesterone,with its anti-inflammatory properties and presence in the nervous system,offers a novel option for Parkinson's disease therapy.Its ability to enhance neuroprotection within the enteric nervous system presents exciting prospects.The review addresses the hypothesis thatα-synuclein aggregates originate from the gut and may enter the brain via the vagus nerve.Gastrointestinal symptoms preceding motor symptoms support this hypothesis.Dysfunctional gut-brain signaling during gut dysbiosis contributes to inflammation and neurotransmitter imbalances,emphasizing the potential of microbiota-based interventions.In summary,this review uncovers the complex web of interactions between nutrition,the gut microbiome,steroid hormones,and Parkinson's disease within the gut-brain axis framework.Understanding these connections not only offers novel therapeutic insights but also illuminates the origins of neurodegenerative diseases such as Parkinson's disease.

Amyloid-beta and tau protein beyond Alzheimer's disease

The aggregation of amyloid-beta peptide and tau protein dysregulation are implicated to play key roles in Alzheimer's disease pathogenesis and are considered the main pathological hallmarks of this devastating disease.Physiologically,these two proteins are produced and expressed within the normal human body.However,under pathological conditions,abnormal expression,posttranslational modifications,conformational changes,and truncation can make these proteins prone to aggregation,triggering specific disease-related cascades.Recent studies have indicated associations between aberrant behavior of amyloid-beta and tau proteins and various neurological diseases,such as Alzheimer's disease,Parkinson's disease,and amyotrophic lateral sclerosis,as well as retinal neurodegenerative diseases like Glaucoma and age-related macular degeneration.Additionally,these proteins have been linked to cardiovascular disease,cancer,traumatic brain injury,and diabetes,which are all leading causes of morbidity and mortality.In this comprehensive review,we provide an overview of the connections between amyloid-beta and tau proteins and a spectrum of disorders.

Lactate metabolism in neurodegenerative diseases

Lactate,a byproduct of glycolysis,was thought to be a metabolic waste until the discovery of the Warburg effect.Lactate not only functions as a metabolic substrate to provide energy but can also function as a signaling molecule to modulate cellular functions under pathophysiological conditions.The Astrocyte-Neuron Lactate Shuttle has cla rified that lactate plays a pivotal role in the central nervous system.Moreover,protein lactylation highlights the novel role of lactate in regulating transcription,cellular functions,and disease development.This review summarizes the recent advances in lactate metabolism and its role in neurodegenerative diseases,thus providing optimal pers pectives for future research.

Muscle strength and non-alcoholic fatty liver disease/metabolicassociated fatty liver disease

This editorial comments on an article published in a recent issue of World Journal of Gastroenterology,entitled“Association of low muscle strength with metabolic dysfunction-associated fatty liver disease:A nationwide study”.We focused on the association between muscle strength and the incidence of non-alcoholic fatty liver disease(NAFLD)and metabolic-associated fatty liver disease(MAFLD),as well as the mechanisms underlying the correlation and related clinical applications.NAFLD,which is now redefined as MAFLD,is one of the most common chronic liver diseases globally with an increasing prevalence and is characterized by malnutrition,which may contribute to decreased muscle strength.Reduction of muscle strength reportedly has a pathogenesis similar to that of NAFLD/MAFLD,including insulin resistance,inflammation,sedentary behavior,as well as insufficient vitamin D.Multiple studies have focused on the relationship between sarcopenia or muscle strength and NAFLD.However,studies investigating the relationship between muscle strength and MAFLD are limited.Owing to the shortage of specific medications for NAFLD/MAFLD treatment,early detection is essential.Furthermore,the relationship between muscle strength and NAFLD/MAFLD suggests that improvements in muscle strength may have an impact on disease prevention and may provide novel insights into treatments including dietary therapy,as well as tailored physical activity.

Neuroprotective effects of chaperone-mediated autophagy in neurodegenerative diseases

Chaperone-mediated autophagy is one of three types of autophagy and is characterized by the selective degradation of proteins.Chaperone-mediated autophagy contributes to energy balance and helps maintain cellular homeostasis,while providing nutrients and support for cell survival.Chaperone-mediated autophagy activity can be detected in almost all cells,including neurons.Owing to the extreme sensitivity of neurons to their environmental changes,maintaining neuronal homeostasis is critical for neuronal growth and survival.Chaperone-mediated autophagy dysfunction is closely related to central nervous system diseases.It has been shown that neuronal damage and cell death are accompanied by chaperone-mediated autophagy dysfunction.Under certain conditions,regulation of chaperone-mediated autophagy activity attenuates neurotoxicity.In this paper,we review the changes in chaperone-mediated autophagy in neurodegenerative diseases,brain injury,glioma,and autoimmune diseases.We also summarize the most recent research progress on chaperone-mediated autophagy regulation and discuss the potential of chaperone-mediated autophagy as a therapeutic target for central nervous system diseases.

Mitophagy in neurodegenerative disease pathogenesis

Mitochondria are critical cellular energy resources and are central to the life of the neuron.Mitophagy selectively clears damaged or dysfunctional mitochondria through autophagic machinery to maintain mitochondrial quality control and homeostasis.Mature neurons are postmitotic and consume substantial energy,thus require highly efficient mitophagy pathways to turn over damaged or dysfunctional mitochondria.Recent evidence indicates that mitophagy is pivotal to the pathogenesis of neurological diseases.However,more work is needed to study mitophagy pathway components as potential therapeutic targets.In this review,we briefly discuss the characteristics of nonselective autophagy and selective autophagy,including ERphagy,aggrephagy,and mitophagy.We then introduce the mechanisms of Parkin-dependent and Parkin-independent mitophagy pathways under physiological conditions.Next,we summarize the diverse repertoire of mitochondrial membrane receptors and phospholipids that mediate mitophagy.Importantly,we review the critical role of mitophagy in the pathogenesis of neurodegenerative diseases including Alzheimer’s disease,Parkinson’s disease,and amyotrophic lateral sclerosis.Last,we discuss recent studies considering mitophagy as a potential therapeutic target for treating neurodegenerative diseases.Together,our review may provide novel views to better understand the roles of mitophagy in neurodegenerative disease pathogenesis.

SIRT2 as a potential new therapeutic target for Alzheimer's disease

Alzheimer's disease is the most common cause of dementia globally with an increasing incidence over the years,bringing a heavy burden to individuals and society due to the lack of an effective treatment.In this context,sirtuin 2,the sirtuin with the highest expression in the brain,has emerged as a potential therapeutic target for neurodegenerative diseases.This review summarizes and discusses the complex roles of sirtuin 2 in different molecular mechanisms involved in Alzheimer's disease such as amyloid and tau pathology,microtubule stability,neuroinflammation,myelin formation,autophagy,and oxidative stress.The role of sirtuin 2 in all these processes highlights its potential implication in the etiology and development of Alzheimer's disease.However,its presence in different cell types and its enormous variety of substrates leads to apparently contra dictory conclusions when it comes to understanding its specific functions.Further studies in sirtuin 2 research with selective sirtuin2 modulators targeting specific sirtuin 2 substrates are necessary to clarify its specific functions under different conditions and to validate it as a novel pharmacological target.This will contribute to the development of new treatment strategies,not only for Alzheimer's disease but also for other neurodegenerative diseases.

Antisense therapy:a potential breakthrough in the treatment of neurodegenerative diseases

Neurodegenerative diseases are a group of disorders characterized by the progressive degeneration of neurons in the central or peripheral nervous system.Currently,there is no cure for neurodegenerative diseases and this means a heavy burden for patients and the health system worldwide.Therefore,it is necessary to find new therapeutic approaches,and antisense therapies offer this possibility,having the great advantage of not modifying cellular genome and potentially being safer.Many preclinical and clinical studies aim to test the safety and effectiveness of antisense therapies in the treatment of neurodegenerative diseases.The objective of this review is to summarize the recent advances in the development of these new technologies to treat the most common neurodegenerative diseases,with a focus on those antisense therapies that have already received the approval of the U.S.Food and Drug Administration.