Surgical tips for the implantation of BDYNTM dynamic stabilization system: combining spinal navigation with motion preservation for low-grade lumbar degenerative spondylolisthesis.

BACKGROUND: As required in every dynamic stabilization system, the implantation of the BDYNTM device implies a perfect positioning of the screws and rods to benefit from its biomechanical properties. To achieve this goal, intra-operative imaging seems mandatory. METHOD: Through a case report of a patient with symptomatic grade I lumbar degenerative spondylolisthesis, we present the surgical tips for the implantation of BDYNTM dynamic stabilization system under the assistance of spinal navigation Surgivisio® 2D/3D. CONCLUSION: The pedicular screw convergence, their placement in the pedicles, and the proper alignment of the BDYNTM system placed in neutral position are important steps of the surgery. Intra-operative spinal navigation helps achieving precise and safe positioning of the dynamic stabilization BDYNTM device taking optimal advantages of its biomechanical characteristics.

Minimally invasive microsurgical treatment of spinal dural arteriovenous fistula: how I do it.

BACKGROUND: Spinal dural arteriovenous fistula (d-AVF) is the most common spinal vascular malformations. Management includes endovascular embolization, and/or surgical obliteration of the shunt. METHOD: Applied to spinal d-AVF, mini-invasive surgical (MIS) obliteration is described as a mini-open approach using Mast Quadrant™ system. Important anatomical landmarks are reviewed. Indications, advantages, and limitations are discussed, and a step-by-step description of the procedure is presented. CONCLUSION: MIS is a good solution to treat d-AVF with a good outcome.

Description of a giant hypothalamic hamartoma associated with an immature ruptured giant sacrococcygeal teratoma: a case report.

Giant hypothalamic hamartomas (GHH) are rare neonatal intracerebral congenital malformations responsible for gelastic epilepsy and/or endocrine disturbances. Sacrococcygeal teratomas (SCT) are fetal neoplasms associated with perinatal morbidity and mortality, especially hemorrhagic complications in giant examples (GSCT). Here, we describe an immature ruptured GSCT complicated by hemorrhagic shock at 32-week gestation boy requiring an emergency delivery, followed immediately by urgent surgical removal. A brain lesion resembling a GHH was also present on the antenatal MRI. In order to exclude metastatic immature teratoma or glioma, a biopsy was performed by a retro-sigmoidal approach, which confirmed the nature of the hamartoma. Here, we describe for the first time the association of a ruptured immature GSCT associated with a GHH.

Corrective GUSB transfer to the canine mucopolysaccharidosis VII brain.

Severe deficiency in lysosomal ß-glucuronidase (ß-glu) enzymatic activity results in mucopolysaccharidosis (MPS) VII, an orphan disease with symptoms often appearing in early childhood. Symptoms are variable, but many patients have multiple organ disorders including neurological defects. At the cellular level, deficiency in ß-glu activity leads to abnormal accumulation of glycosaminoglycans (GAGs), and secondary accumulation of GM2 and GM3 gangliosides, which have been linked to neuroinflammation. There have been encouraging gene transfer studies in the MPS VII mouse brain, but this is the first study attempting the correction of the >200-fold larger and challenging canine MPS VII brain. Here, the efficacy of a helper-dependent (HD) canine adenovirus (CAV-2) vector harboring a human GUSB expression cassette (HD-RIGIE) in the MPS VII dog brain was tested. Vector genomes, ß-glu activity, GAG content, lysosome morphology and neuropathology were analyzed and quantified. Our data demonstrated that CAV-2 vectors preferentially transduced neurons and axonal retrograde transport from the injection site to efferent regions was efficient. HD-RIGIE injections, associated with mild and transient immunosuppression, corrected neuropathology in injected and noninjected structures throughout the cerebrum. These data support the clinical evaluation of HD CAV-2 vectors to treat the neurological defects associated with MPS VII and possibly other neuropathic lysosomal storage diseases.

Characterization and comparison of 5 platelet-rich plasma preparations in a single-donor model.

PURPOSE: The purpose of this study was to compare the biological characteristics of platelet-rich plasma (PRP) obtained from 4 medical devices and a preparation developed in our laboratory using a single-donor model. METHODS: Ten healthy persons donated blood that was processed to produce PRP by use of 4 commercial preparation systems and a protocol developed in our laboratory. Volumes and platelet, white blood cell (WBC), and red blood cell concentrations were recorded. The platelet activation status was assessed by flow cytometry. Enzyme-linked immunosorbent assay was used to determine the concentrations of vascular endothelial growth factor, platelet-derived growth factor AB, epidermal growth factor, and transforming growth factor ß1. We calculated platelet capture efficiency, relative composition, and increase factors from whole blood in platelets and WBC, as well as platelet and growth factor (GF) doses, provided from each preparation. RESULTS: Leukocyte-rich PRP was obtained with RegenPRP (RegenLab, Le Mont-sur-Lausanne, Switzerland) and the Mini GPS III System (Biomet Biology, Warsaw, IN) and provides PRP with higher proportions of red blood cells, WBCs, and neutrophils than leukocyte-poor PRP obtained with the Selphyl System (Selphyl, Bethlehem, PA), Arthrex ACP (Arthrex, Naples, FL), and the preparation developed in our laboratory. The highest platelet and GF concentrations and doses were obtained with the Mini GPS III System and the preparation developed in our laboratory. Different centrifugation protocols did not show differences in the percentages of activated platelets. Finally, a positive correlation between platelet doses and all the GFs studied was found, whereas a positive correlation between WBC doses and GFs was found only for vascular endothelial growth factor and epidermal growth factor. CONCLUSIONS: In a single-donor model, significant biological variations in PRP obtained from different preparation systems were highlighted. The observed differences suggest different results for treated tissue and could explain the large variability in the clinical benefit of PRP reported in the literature. CLINICAL RELEVANCE: Our findings will help clinicians to choose a system that meets their specific needs for a given indication.

An updated classification of the anatomical variations of the internal iliac venous drainage system: Surgical implications for anterior lumbar spinal approaches.

BACKGROUND: Advanced pelvic surgery is associated with potential vascular risks. The aim of this study was to complete the existing classification of the anatomical variations of the internal iliac veins encountered on a series of preoperative angio CT with a view to performing anterior lumbar spine surgery. MATERIALS AND METHODS: In this monocentric retrospective study conducted between 2010 and 2020, all preoperative angio CT performed before an anterior lumbar surgery were systematically analyzed. All the abnormalities of the iliac veins were referenced in an updated classification system. RESULTS: 910 patients (431 men and 479 women) with a mean age of 49 years [16-88] were included. Apart from the most common variant in the population (type I), 64 anatomical variations (7.0%) in the iliac veins were reported and classified according to our new classification. The percentage of coverage of the L4-L5 intervertebral disc is 52%, including 32% by the inferior vena cava before the confluence of the common iliac veins. At the level of the L5-S1 intervertebral disc, the coverage is 30% (same distribution between left and right). CONCLUSIONS: Variations of the iliac veins are frequent, and contrary to what one might think, and even if they can represent an anatomical trap during surgery, certain variations do not limit anterior lumbar spine surgery and are not more associated with vascular complications. Nevertheless, these anatomical variations must be known before any advanced pelvic surgery. Depending on their distribution, level L5-S1 is more suitable for ALIF, level L4-L5 for OLIF approaches.

Efficacy of the immediate adipose-derived stromal vascular fraction autograft on functional sensorimotor recovery after spinal cord contusion in rats.

BACKGROUND: Spinal cord injuries (SCI) lead to functional alteration with important consequences such as motor and sensory disorders. The repair strategies developed to date remain ineffective. The adipose tissue-derived stromal vascular fraction (SVF) is composed of a cocktail of cells with trophic, pro-angiogenic and immunomodulatory effects. Numerous therapeutic benefits were shown for tissue reconstitution, peripheral neuropathy and for the improvement of neurodegenerative diseases. Here, the therapeutic efficacy of SVF on sensorimotor recovery after an acute thoracic spinal cord contusion in adult rats was determined. METHOD: Male Sprague Dawley rats (n = 45) were divided into 3 groups: SHAM (without SCI and treatment), NaCl (animals with a spinal lesion and receiving a saline injection through the dura mater) and SVF (animals with a spinal lesion and receiving a fraction of fat removed from adipocytes through the dura mater). Some animals were sacrificed 14 days after the start of the experiment to determine the inflammatory reaction by measuring the interleukin-1ß, interleukin-6 and Tumor Necrosis Factor-α in the lesion area. Other animals were followed once a week for 12 weeks to assess functional recovery (postural and locomotor activities, sensorimotor coordination). At the end of this period, spinal reflexivity (rate-dependent depression of the H-reflex) and physiological adjustments (ventilatory response to metabosensitive muscle activation following muscle fatigue) were measured with electrophysiological tools. RESULTS: Compared to non-treated animals, results indicated that the SVF reduced the endogenous inflammation and increased the behavioral recovery in treated animals. Moreover, H-reflex depression and ventilatory adjustments to muscle fatigue were found to be comparable between SHAM and SVF groups. CONCLUSION: Our results highlight the effectiveness of SVF and its high therapeutic potential to improve sensorimotor functions and to restore the segmental sensorimotor loop and the communication between supra- and sub-lesional spinal cord regions after traumatic contusion.

Radiological factors affecting functional outcome after the implantation of BDYN™ dynamic stabilization system for low-grade lumbar degenerative spondylolisthesis.

BACKGROUND: The objectives of this study are to identify radiological factors associated with good functional outcomes after the implantation of BDYN™ dynamic stabilization system in the setting of painful low-grade degenerative lumbar spondylolisthesis (DLS). MATERIAL AND METHODS: In this monocentric, retrospective study, we followed 50 patients, a 5-years period, with chronic lower back pain, radiculopathy and/or neurogenic claudication evolving for at least one year that failed conservative treatment. All patients presented low-grade DLS and underwent lumbar dynamic stabilization. Radiological and clinical outcomes were assessed preoperatively and 24months after surgery. Functional evaluation was based on the Oswestry Disability Index (ODI), the Numerical Rating Scale (NRS), and the Walking Distance (WD). Radiological analysis was based on lumbar X-rays and MRI parameters. Patients were divided into two groups according to the reduction in the postoperative ODI score (more or less than 15 points), and statistical analysis was performed between both groups to find predictive radiological factors for a satisfying functional outcome. RESULTS: Clinically, 80% (40 patients) had a satisfying functional result, and 20% (10 patients) were considered having a poor outcome according to the ODI score. Radiologically, the loss in segmental lordosis was statistically associated with bad functional outcomes (18° for ODI decrease>15 versus 11° for ODI decrease<15). There is also a tendency showing that a higher Pfirmann disc signal grade (grade IV) and a severe canal stenosis according to Schizas classification (grade C & D) are predictive of a poor clinical result, but that must be confirmed in future studies. CONCLUSIONS: BDYN™ appears safe and well-tolerated. This new device should be effective for the treatment of patients with low-grade DLS. It provides significant improvement in terms of daily life activity and pain. Moreover, we have been able to deduce that a kyphotic disc is associated with a bad functional outcome after BDYN™ device implantation. It may represent a contraindication for the implantation of such DS device. Moreover, it seems that it is better to implant BDYN™ in DLS with mild or moderate disc degeneration and canal stenosis.

Fatigue in Multiple Sclerosis: A Review of the Exploratory and Therapeutic Potential of Non-Invasive Brain Stimulation.

Fatigue is the most commonly reported symptom in patients with multiple sclerosis (MS). It is a worrisome, frequent, and debilitating manifestation that could occur at any time during the course of MS and in all its subtypes. It could engender professional, familial, and socioeconomic consequences and could severely compromise the patients' quality of life. Clinically, the symptom exhibits motor, cognitive, and psychosocial facets. It is also important to differentiate between perceived or subjective self-reported fatigue and fatigability which is an objective measure of decrement in the performance of cognitive or motor tasks. The pathophysiology of MS fatigue is complex, and its management remains a challenge, despite the existing body of literature on this matter. Hence, unraveling its neural mechanisms and developing treatment options that target the latter might constitute a promising field to explore. A PubMed/Medline/Scopus search was conducted to perform this review which aims (a) to reappraise the available electrophysiological studies that explored fatigue in patients with MS with a particular focus on corticospinal excitability measures obtained using transcranial magnetic stimulation and (b) to assess the potential utility of employing neuromodulation (i.e., non-invasive brain stimulation techniques) in this context. A special focus will be put on the role of transcranial direct current stimulation and transcranial magnetic stimulation. We have provided some suggestions that will help overcome the current limitations in upcoming research.

Ten Years After SINS: Role of Surgery and Radiotherapy in the Management of Patients With Vertebral Metastases.

The objective of the different types of treatments for a spinal metastasis is to provide the best oncological and functional result with the least aggressive side effects. Initially created in 2010 to help clinicians in the management of vertebral metastases, the Spine Instability Neoplastic Score (SINS) has quickly found its place in the decision making and the treatment of patients with metastatic spinal disease. Here we conduct a review of the literature describing the different changes that occurred with the SINS score in the last ten years. After a brief presentation of the spinal metastases' distribution, with or without spinal cord compression, we present the utility of SINS in the radiological diagnosis and extension of the disease, in addition to its limits, especially for scores ranging between 7 and 12. We take this opportunity to expose the latest advances in surgery and radiotherapy concerning spinal metastases, as well as in palliative care and pain control. We also discuss the reliability of SINS amongst radiologists, radiation oncologists, spine surgeons and spine surgery trainees. Finally, we will present the new SINS-derived predictive scores, biomarkers and artificial intelligence algorithms that allow a multidisciplinary approach for the management of spinal metastases.

CT-Guided Aspiration of a Hemorrhagic Tarlov Cyst for the Treatment of a Post-Partum Sciatica: A Case Report and a Review of the Literature.

Background: Tarlov or perineural cysts are dilations of nerve roots resulting from a pathologically increased cerebrospinal fluid pressure. Although it is very common in the general population, most of these cysts remain asymptomatic. In some cases, they can evolve and exert pressure on neural elements, independently from their initial size. Case report: In this paper, we describe the case of a 33-year-old female known to have asymptomatic multiple and large radicular and pelvic Tarlov cysts. One cyst located in the right pelvic space progressed acutely after delivery, inducing a painful sciatica without neurological deficit. The intracystic bleeding can be a direct consequence of the delivery, leading to an acute and mechanical local compression of the right S1 root. A CT-guided puncture and aspiration allowed a complete recovery. This case report was completed by a review of the literature of these rare intracystic Tarlov bleedings. Conclusions: Intracystic hemorrhage is a rare complication of Tarlov cysts. Delivery-induced cyst bleeding was not described before. Patients known to have large and multiple Tarlov cysts should be monitored in post-partum, as their presence is considered a risk factor. Percutaneous cyst aspiration seems to be an effective and safe treatment to relieve symptoms.

Spinal meningiomas, from biology to management - A literature review.

Meningiomas arise from arachnoidal cap cells of the meninges, constituting the most common type of central nervous system tumors, and are considered benign tumors in most cases. Their incidence increases with age, and they mainly affect females, constituting 25-46% of primary spinal tumors. Spinal meningiomas could be detected incidentally or be unraveled by various neurological symptoms (e.g., back pain, sphincter dysfunction, sensorimotor deficits). The gold standard diagnostic modality for spinal meningiomas is Magnetic resonance imaging (MRI) which permits their classification into four categories based on their radiological appearance. According to the World Health Organization (WHO) classification, the majority of spinal meningiomas are grade 1. Nevertheless, they can be of higher grade (grades 2 and 3) with atypical or malignant histology and a more aggressive course. To date, surgery is the best treatment where the big majority of meningiomas can be cured. Advances in surgical techniques (ultrasonic dissection, microsurgery, intraoperative monitoring) increase the complete resection rate. Operated patients have a satisfactory prognosis, even in those with poor preoperative neurological status. Adjuvant therapy has a growing role in treating spinal meningiomas, mainly in the case of subtotal resection and tumor recurrence. The current paper reviews the fundamental epidemiological and clinical aspects of spinal meningiomas, their histological and genetic characteristics, and their management, including the various surgical novelties and techniques.

Aldehyde dehydrogenase activity promotes survival of human muscle precursor cells.

Aldehyde dehydrogenases (ALDH) are a family of enzymes that efficiently detoxify aldehydic products generated by reactive oxygen species and might therefore participate in cell survival. Because ALDH activity has been used to identify normal and malignant cells with stem cell properties, we asked whether human myogenic precursor cells (myoblasts) could be identified and isolated based on their levels of ALDH activity. Human muscle explant-derived cells were incubated with ALDEFLUOR, a fluorescent substrate for ALDH, and we determined by flow cytometry the level of enzyme activity. We found that ALDH activity positively correlated with the myoblast-CD56(+) fraction in those cells, but, we also observed heterogeneity of ALDH activity levels within CD56-purified myoblasts. Using lentiviral mediated expression of shRNA we demonstrated that ALDH activity was associated with expression of Aldh1a1 protein. Surprisingly, ALDH activity and Aldh1a1 expression levels were very low in mouse, rat, rabbit and non-human primate myoblasts. Using different approaches, from pharmacological inhibition of ALDH activity by diethylaminobenzaldehyde, an inhibitor of class I ALDH, to cell fractionation by flow cytometry using the ALDEFLUOR assay, we characterized human myoblasts expressing low or high levels of ALDH. We correlated high ALDH activity ex vivo to resistance to hydrogen peroxide (H(2) O(2) )-induced cytotoxic effect and in vivo to improved cell viability when human myoblasts were transplanted into host muscle of immune deficient scid mice. Therefore detection of ALDH activity, as a purification strategy, could allow non-toxic and efficient isolation of a fraction of human myoblasts resistant to cytotoxic damage.

Segmental Lordosis Gain Is a Prognostic Radiological Factor of Good Functional Outcome After the Implantation of a Single-Level Prosthesis or a Hybrid Construct for Lumbar Disc Degeneration.

OBJECTIVE: To identify radiological factors and functional outcomes associated with good results after implantation of a single lumbar disc prosthesis or a hybrid construct (anterior lumbar interbody fusion and lumbar disc prosthesis) in the setting of painful degenerative lumbar discopathy. METHODS: This single-center, retrospective 10-year study included 92 patients ˃18 years old with chronic low back pain evolving for at least 1 year. The patients had degenerative disc disease and had failed conservative treatment and underwent lumbar arthroplasty. Radiographic and clinical outcomes were assessed preoperatively and 1 year after surgery. Functional evaluation was based on the Oswestry Disability Index (ODI) and a numerical rating scale. Radiological analysis was based on lumbar x-rays and magnetic resonance imaging parameters. Patients were assigned to 2 groups according to the reduction in ODI score (>15 points or <15 points), and statistical analysis was done in both groups to find predictive radiological factors for a satisfactory functional outcome. RESULTS: Clinically, 60 patients (65.2%) had a satisfactory functional result and 32 patients (34.8%) had a poor outcome according to ODI score. Radiographically, gain in segmental lordosis was statistically associated with good functional outcomes (8.9° for ODI decrease >15 vs. 3.2° for ODI decrease <15). CONCLUSIONS: This study determined that gain in segmental lordosis is associated with a satisfactory functional outcome after a single-level lumbar disc prosthesis or a hybrid construct. Our study demonstrates that segmental lordosis gain may represent a significative useful positive predictor factor of patient outcome.

Case Report: A Rare Case of Fourth Ventricle to Spinal Subarachnoid Space Shunt Migration: Surgical Pearl and Literature Review.

Background: In the event of syringomyelia communicating with the fourth ventricle, a fourth ventricle to cervical subarachnoid space shunting could be proposed. Case Report: In this review article, we describe the case of a 40-year-old woman who had a previously implanted fourth ventricle to spinal subarachnoid space shunt for the treatment of syringomyelia in the context of Chiari syndrome. The catheter migrated intradurally to the lumbosacral space, but in the absence of neurological repercussions, we decided to leave it in place. Conclusions: To the best of our knowledge, this is the first case described in the literature review of a catheter migration in the subarachnoid space from occipitocervical to lumbosacral level.

Physiopathological Relevance of D-Serine in the Mammalian Cochlea.

NMDA receptors (NMDARs) populate the complex between inner hair cell (IHC) and spiral ganglion neurons (SGNs) in the developing and mature cochlea. However, in the mature cochlea, activation of NMDARs is thought to mainly occur under pathological conditions such as excitotoxicity. Ototoxic drugs such as aspirin enable cochlear arachidonic-acid-sensitive NMDAR responses, and induced chronic tinnitus was blocked by local application of NMDAR antagonists into the cochlear fluids. We largely ignore if other modulators are also engaged. In the brain, D-serine is the primary physiological co-agonist of synaptic NMDARs. Whether D-serine plays a role in the cochlea had remained unexplored. We now reveal the presence of D-serine and its metabolic enzymes prior to, and at hearing onset, in the sensory and non-neuronal cells of the cochlea of several vertebrate species. In vivo intracochlear perfusion of D-serine in guinea pigs reduces sound-evoked activity of auditory nerve fibers without affecting the receptor potentials, suggesting that D-serine acts specifically on the postsynaptic auditory neurons without altering the functional state of IHC or of the stria vascularis. Indeed, we demonstrate in vitro that agonist-induced activation of NMDARs produces robust calcium responses in rat SGN somata only in the presence of D-serine, but not of glycine. Surprisingly, genetic deletion in mice of serine racemase (SR), the enzyme that catalyzes D-serine, does not affect hearing function, but offers protection against noise-induced permanent hearing loss as measured 3 months after exposure. However, the mechanisms of activation of NMDA receptors in newborn rats may be different from those in adult guinea pigs. Taken together, these results demonstrate for the first time that the neuro-messenger D-serine has a pivotal role in the cochlea by promoting the activation of silent cochlear NMDAR in pathological situations. Thus, D-serine and its signaling pathway may represent a new druggable target for treating sensorineural hearing disorders (i.e., hearing loss, tinnitus).

Exogenous LRRK2G2019S induces parkinsonian-like pathology in a nonhuman primate.

Parkinson's disease (PD) is the second most prevalent neurodegenerative disease among the elderly. To understand its pathogenesis and to test therapies, animal models that faithfully reproduce key pathological PD hallmarks are needed. As a prelude to developing a model of PD, we tested the tropism, efficacy, biodistribution, and transcriptional effect of canine adenovirus type 2 (CAV-2) vectors in the brain of Microcebus murinus, a nonhuman primate that naturally develops neurodegenerative lesions. We show that introducing helper-dependent (HD) CAV-2 vectors results in long-term, neuron-specific expression at the injection site and in afferent nuclei. Although HD CAV-2 vector injection induced a modest transcriptional response, no significant adaptive immune response was generated. We then generated and tested HD CAV-2 vectors expressing leucine-rich repeat kinase 2 (LRRK2) and LRRK2 carrying a G2019S mutation (LRRK2G2019S), which is linked to sporadic and familial autosomal dominant forms of PD. We show that HD-LRRK2G2019S expression induced parkinsonian-like motor symptoms and histological features in less than 4 months.

Physico-chemical factors influencing autologous conditioned serum purification.

Autologous conditioned serum (ACS) is a recent biotherapy based on certain cytokines anti-inflammatory properties mainly used for the reduction of osteoarthritis (OA) symptoms. Here we investigated different physico-chemical factors influencing ACS purification and cytokine production. Human venous blood was incubated in the presence of different diameter beads (respectively 2.5, 3, 3.5, and 4 mm) or glass beads with different types of coating (polished or coated with CrSO4). Sera were recovered, and the concentrations of pro-inflammatory and anti-inflammatory relevant cytokines were measured using Luminex(®) technology. Fresh whole blood incubated for 24 h highly increased production of interleukin (IL)-6 and IL-8 cytokines. At the same time, the concentrations of IL-1ß, IL-1 receptor agonist (IL-1Ra), IL-10, and tumor necrosis factor (TNF)-α were slightly induced. The highest cytokine concentrations were obtained with the exposure of whole blood to 3-mm glass beads and 3.5-mm polished beads. The minimum IL-1ß/IL-1Ra ratio obtained was 3.2±1.3 after 24-h incubation without any beads. ACS has been shown to alleviate clinical symptoms of OA in clinical studies. This descriptive study demonstrated that different pro- and anti-inflammatory cytokines are present in ACS since no selective anti-inflammatory cytokines were produced based on the different protocols. Furthermore, we showed that CrSO4-treated glass beads are not necessary and that the absence of beads combined with a 24-h incubation could also lead to an enriched serum.

Central nervous system delivery of helper-dependent canine adenovirus corrects neuropathology and behavior in mucopolysaccharidosis type VII mice.

Canine adenovirus type 2 vectors (CAV-2) are promising tools to treat global central nervous system (CNS) disorders because of their preferential transduction of neurons and efficient retrograde axonal transport. Here we tested the potential of a helper-dependent CAV-2 vector expressing ß-glucuronidase (HD-RIGIE) in a mouse model of mucopolysaccharidosis type VII (MPS VII), a lysosomal storage disease caused by deficiency in ß-glucuronidase activity. MPS VII leads to glycosaminoglycan accumulation into enlarged vesicles in peripheral tissues and the CNS, resulting in peripheral and neuronal dysfunction. After intracranial administration of HD-RIGIE, we show long-term expression of ß-glucuronidase that led to correction of neuropathology around the injection site and in distal areas. This phenotypic correction correlated with a decrease in secondary-elevated lysosomal enzyme activity and glycosaminoglycan levels, consistent with global biochemical correction. Moreover, HD-RIGIE-treated mice show significant cognitive improvement. Thus, injections of HD-CAV-2 vectors in the brain allow a global and sustained expression and may have implications for brain therapy in patients with lysosomal storage disease.