Intrathecal pumps

Implantable systems for neurological chronotherapy

Implantable systems for neurological chronotherapy are poised to revolutionize the treatment of central nervous system diseases and disorders. These devices enable precise, time-controlled drug delivery aligned with the body's circadian rhythms, optimizing therapeutic outcomes. By bypassing the blood-brain barrier, they achieve high local drug concentrations while minimizing systemic side effects, offering significant advantages for conditions where traditional therapies often fall short. Platforms like SynchroMed II and CraniUS showcase this innovation, providing programmable delivery for conditions such as epilepsy and glioblastoma, with customizable profiles ranging from continuous infusion to timed bolus administration. Preclinical and clinical studies underscore the efficacy of aligning drug delivery with circadian rhythms, enhancing outcomes in chrono-chemotherapy and anti-epileptic treatments. Despite their promise, challenges remain, including the invasiveness of implantation within the brain, device longevity, synchronization complexities, and cost(s). Accordingly, this review explores the current state of implantable neurological systems that may be leveraged for chronotherapy, their applications, limitations, and potential to transform neurological disease/disorder management.

Caregiver Barriers When Assisting with Intrathecal Infusion Systems: A Literature Review

The widespread implementation of intrathecal infusion systems (IIS) in managing chronic pain underscores the pivotal role of family caregivers in ensuring effective treatment outcomes and enhancing patients' quality of life. We conducted a comprehensive literature search across databases including PubMed, Medline, and Web of Science. Research indicates that family caregivers primarily face barriers such as insufficient professional knowledge, technical difficulties, psychological and emotional strain, and a lack of adequate financial and social support. These challenges can compromise the efficacy of pain management and increase caregivers' burdens. In response, recent studies have concentrated on offering targeted educational programs and training, fostering support networks, and encouraging technological innovations and policy reforms. Such initiatives aim to bolster caregivers' capabilities and alleviate their psychological and financial stress, thereby enhancing the overall effectiveness of pain management strategies. The significance of the review is that it highlights the central role of family carers in chronic pain management and points to the importance of enhancing their caring capacity. Future research directions should include the development of more systematic caregiver support programs, an in-depth exploration of the effectiveness of multidisciplinary collaborative models, and an assessment of the promise of emerging technologies for use in the family caregiving environment.

Thioether-Functionalized Cellulose for the Fabrication of Oxidation-Responsive Biomaterial Coatings and Films

Biomaterial coatings and films can prevent premature failure and enhance the performance of chronically implanted medical devices. However, current hydrophilic polymer coatings and films have significant drawbacks, including swelling and delamination. To address these issues, hydroxyethyl cellulose is modified with thioether groups to generate an oxidation-responsive polymer, HECMTP. HECMTP readily dissolves in green solvents and can be fabricated as coatings or films with tunable thicknesses. HECMTP coatings effectively scavenge hydrogen peroxide, resulting in the conversion of thioether groups to sulfoxide groups on the polymer chain. Oxidation-driven, hydrophobic-to-hydrophilic transitions that are isolated to the surface of HECMTP coatings under physiologically relevant conditions increase wettability, decrease stiffness, and reduce protein adsorption to generate a non-fouling interface with minimal coating delamination or swelling. HECMTP can be used in diverse optical applications and permits oxidation-responsive, controlled drug release. HECMTP films are non-resorbable in vivo and evoke minimal foreign body responses. These results highlight the versatility of HECMTP and support its incorporation into chronically implanted medical devices.

Management of Cerebrospinal Fluid Leak After Intrathecal Baclofen Pump Procedures in Adolescents With Cerebral Palsy: A Retrospective Study

STUDY OBJECTIVE

 Epidural blood patches (EBPs) are frequently performed in children with cerebral palsy (CP) to manage post-dural puncture headache (PDPH) due to cerebrospinal fluid (CSF) leak after intrathecal baclofen pump (ITBP) placement or replacement procedures. The purpose of our study was to review the incidence and management of CSF leak following ITBP placement or replacement procedures in children with CP. The study was a retrospective review of 245 patients representing 310 surgical cases of baclofen pump insertion (n=141) or reinsertion (n=169) conducted at a 125-bed children's hospital with prominent specialty orthopedics surgical cases.

MEASUREMENTS

 Demographic and clinical information was obtained from the anesthesia pain service database on all new ITBP placement and subsequent replacements over an eight-year period.

MAIN RESULTS

 The overall incidence of CSF leak in our population was 16% (50 of 310) and 18% (25 of 141) with a new ITBP placement. Children with diplegia were associated with a threefold risk of developing CSF leak. Of patients who developed CSF leak (n=50), 68% (n=34) were successfully treated conservatively, while 32% (n=16) required EBPs. EBPs were successful in 87.5% (14 of 16) of patients at relieving PDPH on the first attempt.  Conclusions: CSF leak is a known problem after ITBP placement and replacement. Most patients were successfully treated with conservative management and EBPs were successful in patients failing conservative therapy. Diagnosing PDPH in non-verbal patients can be challenging.

A comprehensive review on ziconotide

Managing severe chronic pain is a challenging task, given the limited effectiveness of available pharmacological and non-pharmacological treatments. This issue continues to be a significant public health concern, requiring a substantial therapeutic response. Ziconotide, a synthetic peptide initially isolated from Conus magus in 1982 and approved by the US Food and Drug Administration and the European Medicines Agency in 2004, is the first-line intrathecal method for individuals experiencing severe chronic pain refractory to other therapeutic measures. Ziconotide produces powerful analgesia by blocking N-type calcium channels in the spinal cord, which inhibits the release of pain-relevant neurotransmitters from the central terminals of primary afferent neurons. However, despite possessing many favorable qualities, including the absence of tolerance development, respiratory depression, and withdrawal symptoms (largely due to the absence of a G-protein mediation mechanism), ziconotide's application is limited due to factors such as intrathecal administration and a narrow therapeutic window resulting from significant dose-related undesired effects of the central nervous system. This review aims to provide a comprehensive and clinically relevant summary of the literatures concerning the pharmacokinetics and metabolism of intrathecal ziconotide. It will also describe strategies intended to enhance clinical efficacy while reducing the incidence of side effects. Additionally, the review will explore the current efforts to refine the structure of ziconotide for better clinical outcomes. Lastly, it will prospect potential developments in the new class of selective N-type voltage-sensitive calcium-channel blockers.

Utilizing combination intrathecal baclofen and analgesic medication to manage spasticity and pain in patients with pediatric-onset disability: Case series

PURPOSE

The use of intrathecal medications for the management of spasticity and various pain syndromes in the adult population has been previously reported. However, no evidence-based guidelines currently exist in the pediatric population. This case series presents patients (n = 8) with pediatric-onset disability who underwent placement of intrathecal baclofen pumps initially for management of severe spasticity. Despite titration of dose and use of oral analgesia, their uncontrolled pain persisted. Each patient was transitioned to a combination of baclofen and analgesic intrathecal therapy. The outcome in pain improvement and quality of life, as reported by patients and/or caregivers, were retrospectively reviewed.

METHODS

Retrospective review of the background and decision-making process regarding transition to combination intrathecal therapy identified patient selection characteristics. Each patient and/or their caregivers completed a survey regarding improvements in pain, spasticity, function, and quality of life following initiation of combination intrathecal medications.

RESULTS

Survey results revealed improvements in functional and pain assessments after initiation of combination baclofen and analgesic intrathecal medication. Patients and caregivers reported decreases in pain and oral spasticity medications.

CONCLUSION

Use of pumps with antispasmodic and analgesic medication for combination intrathecal medication delivery should be considered in the management of patients with childhood-onset disabilities who have both severe spasticity and pain.

Implantable device with magnetically rotating disk for needle-free administrations of emergency drug

Prompt administration of first-aid drugs can save lives during medical emergencies such as anaphylaxis and hypoglycemia. However, this is often performed by needle self-injection, which is not easy for patients under emergency conditions. Therefore, we propose an implantable device capable of on-demand administration of first-aid drugs (i.e., the implantable device with a magnetically rotating disk [iMRD]), such as epinephrine and glucagon, via a noninvasive simple application of the magnet from the outside skin (i.e., the external magnet). The iMRD contained a disk embedded with a magnet, as well as multiple drug reservoirs that were sealed with a membrane, which was designed to rotate at a precise angle only when the external magnet was applied. During this rotation, the membrane on a designated single-drug reservoir was aligned and torn to expose the drug to the outside. When implanted in living animals, the iMRD, actuated by an external magnet, delivers epinephrine and glucagon, similar to conventional subcutaneous needle injections.

Biomaterial-Mediated Factor Delivery for Spinal Cord Injury Treatment

Spinal cord injury (SCI) is an injurious process that begins with immediate physical damage to the spinal cord and associated tissues during an acute traumatic event. However, the tissue damage expands in both intensity and volume in the subsequent subacute phase. At this stage, numerous events exacerbate the pathological condition, and therein lies the main cause of post-traumatic neural degeneration, which then ends with the chronic phase. In recent years, therapeutic interventions addressing different neurodegenerative mechanisms have been proposed, but have met with limited success when translated into clinical settings. The underlying reasons for this are that the pathogenesis of SCI is a continued multifactorial disease, and the treatment of only one factor is not sufficient to curb neural degeneration and resulting paralysis. Recent advances have led to the development of biomaterials aiming to promote in situ combinatorial strategies using drugs/biomolecules to achieve a maximized multitarget approach. This review provides an overview of single and combinatorial regenerative-factor-based treatments as well as potential delivery options to treat SCIs.

Intrathecal Drug Delivery: Advances and Applications in the Management of Chronic Pain Patient

Advances in our understanding of the biology of spinal systems in organizing and defining the content of exteroceptive information upon which higher centers define the state of the organism and its role in the regulation of somatic and automatic output, defining the motor response of the organism, along with the unique biology and spatial organization of this space, have resulted in an increased focus on therapeutics targeted at this extracranial neuraxial space. Intrathecal (IT) drug delivery systems (IDDS) are well-established as an effective therapeutic approach to patients with chronic non-malignant or malignant pain and as a tool for management of patients with severe spasticity and to deliver therapeutics that address a myriad of spinal pathologies. The risk to benefit ratio of IDD makes it a useful interventional approach. While not without risks, this approach has a significant therapeutic safety margin when employed using drugs with a validated safety profile and by skilled practioners. The present review addresses current advances in our understanding of the biology and dynamics of the intrathecal space, therapeutic platforms, novel therapeutics, delivery technology, issues of safety and rational implementation of its therapy, with a particular emphasis upon the management of pain.

Implantable system for chronotherapy

Diurnal variation in enzymes, hormones, and other biological mediators has long been recognized in mammalian physiology. Developments in pharmacobiology over the past few decades have shown that timing drug delivery can enhance drug efficacy. Here, we report the development of a battery-free, refillable, subcutaneous, and trocar-compatible implantable system that facilitates chronotherapy by enabling tight control over the timing of drug administration in response to external mechanical actuation. The external wearable system is coupled to a mobile app to facilitate control over dosing time. Using this system, we show the efficacy of bromocriptine on glycemic control in a diabetic rat model. We also demonstrate that antihypertensives can be delivered through this device, which could have clinical applications given the recognized diurnal variation of hypertension-related complications. We anticipate that implants capable of chronotherapy will have a substantial impact on our capacity to enhance treatment effectiveness for a broad range of chronic conditions.

Managing Chronic Non-Malignant Pain in the Elderly: Intrathecal Therapy

Intrathecal drug delivery (IDD) was first described in 1981 by Onofrio, who used a pump for continuous and intrathecal delivery of morphine to treat cancer pain. Over the following four decades, many reports supported this treatment method with implanted pumps for cancer and non-cancer pain. To date, more than 300,000 pumps for pain therapy and spasticity have been implanted worldwide. This article reviews current knowledge regarding intrathecal opioid therapy, focusing particularly on the use of IDD in elderly patients. Current literature is presented, and the arguments in favor of and against this therapy in elderly patients are discussed.

Wirelessly Controlled Implantable System for On-demand and Pulsatile Insulin Administration

We propose a wirelessly controlled implantable system for on-demand and pulsatile insulin delivery with a more convenient and safer strategy than currently available strategies. The system is a combined entity of a magnetically driven pump (i.e., an MDP), external control device (i.e., an ECD) and mobile app. The MDP for implantation consists of a plunger, barrel and drug reservoir, where an accurate amount of insulin can be infused in a pulsatile manner only at the time when a magnetic force is applied to actuate the plunger in the barrel. The ECD at the outside body can modulate the MDP actuation with an electromagnet and its control circuit, and this modulation can be wirelessly controlled by the mobile app. As a safety feature, the mobile app is programmed to pre-set the restrictions for the insulin dose and administration schedule to avoid overdose. The system is shown to infuse insulin in a highly reproducible manner, but it does not allow for insulin infusion when the pre-set restrictions are violated. When tested with diabetic rats, the profiles of insulin plasma concentration and blood glucose level are similar to those of animals treated with a subcutaneous injection of the same dose of insulin.

Interventional Anesthetic Methods for Pain in Hematology/Oncology Patients

This article reviews anesthetic interventional approaches to the management of pain in hematology and oncology patients. It includes a discussion of single interventions including peripheral nerve blocks, plexus injections, and sympathetic nerve neurolysis, and continuous infusion therapy through implantable devices, such as intrathecal pumps, epidural port-a-caths, and tunneled catheters. The primary objective is to inform members of hematology and oncology care teams regarding the variety of interventional options for patients with cancer-related pain for whom medical pain management methods have not been effective.

Novel Association Between Intrathecal Drug Administration and Arachnoiditis Ossificans

BACKGROUND

We present a case of delayed progression of adhesive arachnoiditis to arachnoiditis ossificans (AO) in a patient being treated with a high-dose polypharmaceutical intrathecal regimen.

CASE DESCRIPTION

The patient is a 39-year-old Caucasian male who was implanted with an intrathecal pump in 2006 to control severe low back pain and administered intrathecal pain medication for a period of 10 years. In 2016, he developed new-onset radicular pain and worsened sensation in his lower extremities. Computed tomography scan of the lumbar spine at that time demonstrated profound calcification of the arachnoid consistent with a diagnosis of AO. It was presumed that prolonged high-dose intrathecal medication precipitated this condition, and his intrathecal medications were titrated down with removal of the pump.

CONCLUSIONS

It is unlikely that his condition occurred as a result of prior surgery, with the more likely cause being hyperplasia of the spinal arachnoid, leading to scarring and calcification, due to the high-dose intrathecal regimen. This case highlights the delayed progression from stable arachnoiditis to AO concurring with a regimen of high-dose intrathecal medications. Clinicians should closely monitor patients undergoing intrathecal drug administration, particularly at elevated doses, for indications of damage to the spinal arachnoid mater.

Is 2-Hydroxypropyl-β-cyclodextrin a Suitable Carrier for Central Administration of Δ9 -Tetrahydrocannabinol? Preclinical Evidence

Preclinical Research Δ⁹ -Tetrahydrocannabinol (THC) is a hydrophobic compound that has a potent antinociceptive effect in animals after intrathecal (IT) or intracerebroventricular (ICV) administration. The lack of a suitable solvent precludes its IT administration in humans. 2-Hydroxypropyl-β-cyclodextrin (HPβCD) increases the water solubility of hydrophobic drugs and is approved for IT administration in humans. To investigate whether HPβCD might be a suitable carrier for ICV administration of THC in rats, two formulations containing THC complexed with HPβCD (30 and 135 μg of THC per animal) and vehicle were administered to Wistar rats. The antinociceptive effect (using the tail flick test), locomotor activity, and body temperature were evaluated. ICV injection of 135 μg of THC/HPβCD complex increased tail flick latency, reduced locomotor activity, and had a dual effect on body temperature. The 30 μg THC/HPβCD formulation only produced a hyperthermic effect. All animals appeared healthy, with no difference between the groups. These results were similar to those obtained in other preclinical studies in which THC was administered centrally using solvents that are unsuitable for IT administration in humans because of their toxicity. Our findings suggest that HPβCD may be a useful carrier for IT administration of THC in humans. Drug Dev Res 78 : 411-419, 2017. © 2017 Wiley Periodicals, Inc.

Non-Viral Nucleic Acid Delivery Strategies to the Central Nervous System

With an increased prevalence and understanding of central nervous system (CNS) injuries and neurological disorders, nucleic acid therapies are gaining promise as a way to regenerate lost neurons or halt disease progression. While more viral vectors have been used clinically as tools for gene delivery, non-viral vectors are gaining interest due to lower safety concerns and the ability to deliver all types of nucleic acids. Nevertheless, there are still a number of barriers to nucleic acid delivery. In this focused review, we explore the in vivo challenges hindering non-viral nucleic acid delivery to the CNS and the strategies and vehicles used to overcome them. Advantages and disadvantages of different routes of administration including: systemic injection, cerebrospinal fluid injection, intraparenchymal injection and peripheral administration are discussed. Non-viral vehicles and treatment strategies that have overcome delivery barriers and demonstrated in vivo gene transfer to the CNS are presented. These approaches can be used as guidelines in developing synthetic gene delivery vectors for CNS applications and will ultimately bring non-viral vectors closer to clinical application.

Persistent Spinal Headache After Removal of Intrathecal Drug Delivery System: A Case Report and Review of Literature

Introduction:

To report and discuss the spinal headache following insertion and removal of intrathecal drug delivery system in patients with chronic pain disorders.

Case Presentation:

Intrathecal drug delivery system (IDDS) was initially used for the management of chronic malignant pain; it has since been used to manage pain from other nonmalignant conditions as well. Spinal headache is one of the complications during the trial, permanent placement and after removal of intrathecal drug delivery catheter systems. A 48-year-male patient with chronic pain disorder developed a refractory spinal headache after removing the intrathecal drug delivery system requiring a surgical intervention to resolve the problem.

Conclusions:

Conservative management is successful in the vast majority of patients with spinal headache. Interventional procedures are required in a small fraction of patients for symptomatic relief.

A Prospective, Randomized, Single-Blinded, Head-to-Head Long-Term Outcome Study, Comparing Intrathecal (IT) Boluses With Continuous Infusion Trialing Techniques Prior to Implantation of Drug Delivery Systems (DDS) for the Treatment of Severe Intractable Chronic Nonmalignant Pain

OBJECTIVE

The study aims to compare intrathecal (IT) boluses to continuous infusion trialing techniques prior to implantation of drug delivery systems (DDS) for the treatment of severe intractable chronic nonmalignant pain.

DESIGN

This is a prospective, randomized, head-to-head long-term outcome study.

MATERIALS AND METHODS

Forty patients with comparable patient demographics were randomly assigned to two cohorts. Cohort A trialed with intermittent boluses; Cohort B trialed with continuous infusion. One patient failed trial in each group. Nineteen patients were implanted in each group. Follow-up was for 36 months with intervals at 6, 12, 18, 24, 36 months. The Brief Pain Inventory was used was used for assessment.

OUTCOME MEASURES

We used the Brief Pain Inventory to measure pain (worst and average), physical function (walking, normal work, and general activity), behavioral function (mood, sleep, and relations with others), IT dose, and oral opioid use.

RESULTS

We observed statistically significant reduction in pain and improvement of function in both cohorts following DDS implantation throughout the observation period. The IT dose remained virtually unchanged throughout as well, with overall limited dose escalation. Oral opioid use was significantly reduced. There was no statistically significant difference in prediction of trial success or long-term outcomes between the two cohorts.

CONCLUSION

Low-dose IT opioids via DDS can provide significant and long-lasting reduction in pain, and improvement in function (physical and behavioral) for patients with chronic nonmalignant pain. The two trialing techniques tested, intermittent boluses, and continuous infusion delivered intrathecally showed no clinical significance difference in terms of predicting trial success or long-term outcomes.

Intrathecal pain pumps: indications, patient selection, techniques, and outcomes

Intrathecal drug delivery represents an advanced modality for refractory chronic pain patients as well as intractable spasticity. This article reviews the advantages and indications for intrathecal therapy, as well as recommendations for proper patient selection using a multidisciplinary team to provide a global assessment of the impact of chronic pain on the patient's well-being. The goals and expectations of trialing are discussed alongside advantages and disadvantages of several trialing techniques. A discussion of outcomes is presented for patients with chronic pain due to both malignant and nonmalignant causes.

Managing loss of intrathecal baclofen efficacy: Review of the literature and proposed troubleshooting algorithm

Spasticity is a debilitating symptom associated with numerous neurologic conditions. While intrathecal baclofen therapy (ITB) is an established treatment for spasticity, complications can lead to loss of efficacy (LOE) and baclofen withdrawal. Untreated withdrawal syndrome can be fatal. Prompt diagnosis and management of LOE is essential. Numerous methods have been described in the literature for diagnosing the cause of LOE. Many of the methods require equipment not readily available in the outpatient setting. Furthermore, there is no established consensus on the sequencing of these diagnostic tests. Herein, we review ITB literature on troubleshooting LOE for applicability to the managing clinician. Using this information and our clinical experience, we propose an algorithm with management recommendations to simplify and expedite the troubleshooting process in the outpatient setting.

Regenerative therapies for central nervous system diseases: a biomaterials approach

The central nervous system (CNS) has a limited capacity to spontaneously regenerate following traumatic injury or disease, requiring innovative strategies to promote tissue and functional repair. Tissue regeneration strategies, such as cell and/or drug delivery, have demonstrated promising results in experimental animal models, but have been difficult to translate clinically. The efficacy of cell therapy, which involves stem cell transplantation into the CNS to replace damaged tissue, has been limited due to low cell survival and integration upon transplantation, while delivery of therapeutic molecules to the CNS using conventional methods, such as oral and intravenous administration, have been limited by diffusion across the blood-brain/spinal cord-barrier. The use of biomaterials to promote graft survival and integration as well as localized and sustained delivery of biologics to CNS injury sites is actively being pursued. This review will highlight recent advances using biomaterials as cell- and drug-delivery vehicles for CNS repair.

Intrathecal drug administration in chronic pain syndromes

Chronic pain may recur after initial response to strong opioids in both patients with cancer and patients without cancer or therapy may be complicated by intolerable side effects. When minimally invasive interventional pain management techniques also fail to provide satisfactory pain relief, continuous intrathecal analgesic administration may be considered. Only 3 products have been officially approved for long-term intrathecal administration: morphine, baclofen, and ziconotide. The efficacy of intrathecal ziconotide for the management of patients with severe chronic refractory noncancer pain was illustrated in 3 placebo-controlled trials. A randomized study showed this treatment option to be effective over a short follow-up period for patients with pain due to cancer or AIDS. The efficacy of intrathecal opioid administration for the management of chronic noncancer pain is mainly derived from prospective and retrospective noncontrolled trials. The effect of intrathecal morphine administration in patients with pain due to cancer was compared with oral or transdermal treatment in a randomized controlled trial, which found better pain control and fewer side effects with intrathecal opioids. Other evidence is derived from cohort studies. Side effects of chronic intrathecal therapy may either be technical (catheter or pump malfunction) or biological (infection). The most troublesome complication is, however, the possibility of granuloma formation at the catheter tip that may induce neurological damage. Given limited studies, the evidence for intrathecal drug administration in patients suffering from cancer-related pain is more compelling than that of chronic noncancer pain.

Continuous intrathecal morphine administration for cancer pain management using an intrathecal catheter connected to a subcutaneous injection port: a retrospective analysis of 22 terminal cancer patients in korean population

Background

Intrathecal opioid administration has been used widely in patients suffering from severe cancer pain that is not managed with conventional modalities. However, the potential serious neurological complications from the procedure and the side effects of intrathecal opioids have made many clinicians reluctant to employ continuous intrathecal analgesia as a first-line therapeutic option despite its dramatic effect on intractable pain. We retrospectively investigated the efficacy, side effects, and complications of intrathecal morphine administration through intrathecal catheters connected to a subcutaneous injection port (ICSP) in 22 Korean terminal cancer patients with successful intrathecal morphine trials.

Methods

Patient demographic data, the duration of intrathecal opioid administration, preoperative numerical pain rating scales (NRS) and doses of systemic opioids, side effects and complications related to intrathecal opioids and the procedure, and the numerical pain rating scales and doses of intrathecal and systemic opioids on the 1^st, 3^rd, 7^th and 30^th postoperative days were determined from medical records.

Results

Intrathecal morphine administration for 46.0 ± 61.3 days significantly reduced NRS from baseline on all the postoperative days. A significant increase in intrathecal opioids with a nonsignificant decrease in systemic opioids was observed on the 7^th and 30^th postoperative days compared to the 1^st postoperative day. The most common side effects of intrathecal opioids were nausea/vomiting (31.8%) and urinary retention (38.9%), which were managed with conservative therapies.

Conclusions

Intrathecal morphine administration using ICSP provided immediate and beneficial effects on pain scores with tolerable side effects in terminal cancer patients.

An intrathecally located broken catheter used for an intrathecal drug delivery system

The intrathecal drug delivery system (ITDDS), an effective treatment tool for intractable spasticity and pain, is associated with various complications but breakage of the catheter is rare. We report the case of a 50-yr-old man with ITDDS, in whom an intrathecal catheter was severed, resulting in a 28.6-cm-long intrathecal fragment. The catheter completely retracted into the intrathecal space from the anchor site. The catheter was severed during spine flexion, and the total distal fragment was repositioned in the intrathecal space. Although the outcome of ITDDS was associated with the length or diameter of the broken catheter, no neurologic complications occurred in our patient. Thus, we inserted another catheter instead of removing the old one. Thereafter, the patient has been regularly followed up, and no neurologic complications have developed during the 28 months.

Intrapleural migration of a spinal catheter in a patient with arachnoiditis and extensive epidural scarring after tethered cord release: a case report and review of literature

OBJECTIVE

The objective of this study was to report a case of new onset refractory pain from intrapleural migration of a spinal catheter five months after the implantation of an intrathecal drug delivery system (IDDS).

MATERIALS AND METHODS

A 57-year-old man had intractable pain because of multiple intradural spinal explorations for tethered cord release. His pain was effectively treated with intrathecal morphine via an IDDS. Five months after the implantation, the patient developed return of the original pain more than two weeks after intrapleural migration of the intrathecal catheter.

RESULTS

The migration was documented by computed tomography, and repositioning of the catheter rendered the patient comfortable. The gradual onset of pain may have been due to decreasing delivery of drug to the cerebrospinal fluid as the catheter tip migrated further away from the dura. To our knowledge, this complication has not been reported in the literature.

CONCLUSION

Physicians and nursing staff that place and manage an IDDS should be aware of this complication.

CNS penetration of intrathecal-lumbar idursulfase in the monkey, dog and mouse: implications for neurological outcomes of lysosomal storage disorder

A major challenge for the treatment of many central nervous system (CNS) disorders is the lack of convenient and effective methods for delivering biological agents to the brain. Mucopolysaccharidosis II (Hunter syndrome) is a rare inherited lysosomal storage disorder resulting from a deficiency of iduronate-2-sulfatase (I2S). I2S is a large, highly glycosylated enzyme. Intravenous administration is not likely to be an effective therapy for disease-related neurological outcomes that require enzyme access to the brain cells, in particular neurons and oligodendrocytes. We demonstrate that intracerebroventricular and lumbar intrathecal administration of recombinant I2S in dogs and nonhuman primates resulted in widespread enzyme distribution in the brain parenchyma, including remarkable deposition in the lysosomes of both neurons and oligodendrocytes. Lumbar intrathecal administration also resulted in enzyme delivery to the spinal cord, whereas little enzyme was detected there after intraventricular administration. Mucopolysaccharidosis II model is available in mice. Lumbar administration of recombinant I2S to enzyme deficient animals reduced the storage of glycosaminoglycans in both superficial and deep brain tissues, with concurrent morphological improvements. The observed patterns of enzyme transport from cerebrospinal fluid to the CNS tissues and the resultant biological activity (a) warrant further investigation of intrathecal delivery of I2S via lumbar catheter as an experimental treatment for the neurological symptoms of Hunter syndrome and (b) may have broader implications for CNS treatment with biopharmaceuticals.

Spinal cord compression in Maroteaux-Lamy syndrome: case report and review of the literature with effects of enzyme replacement therapy

The purpose of this report is to review the literature regarding spinal cord compression in mucopolysaccharidosis type VI (MPS VI), to discuss the possible impact of enzyme replacement therapy (ERT) and to stress the necessity of timely surgical intervention. A 9.5-year-old female patient with severe MPS VI had been receiving ERT since the age of 7. After 2.5 years of treatment, she developed craniovertebral canal stenosis with spinal cord compression and cervical myelopathy.

CONCLUSIONS

(1) baseline cervical spine evaluation and regular neurological assessment should be performed in all MPS VI patients, (2) detailed neurological observation should be conducted in patients treated with ERT, especially in the period of improvement in the osteoarticular system, as ERT fails to prevent cervical myelopathy and (3) surgical decompression is required and in order to achieve a satisfying outcome it might be crucial to perform surgery at an early age.

Catheter obstruction of intrathecal drug administration system -a case report-

Intrathecal drug administration system (ITDAS) can reduce the side effects while increasing the effectiveness of opioids compared to systemic opioid administration. Therefore, the use of ITDAS has increased in the management of cancer pain and chronic intractable pain. Catheter obstruction is a serious complication of ITDAS. Here, we present a case of catheter obstruction by a mass formed at the side hole and in the lumen. A 37-year-old man suffering from failed back surgery syndrome received an ITDAS implantation, and the ITDAS was refilled with morphine every 3 months. When the patient visited the hospital 18 months after ITDAS implantation for a refill, the amount of delivered morphine sulfate was much less than expected. Movement of the pump rotor was examined with fluoroscopy; however, it was normal. CSF aspiration through the catheter access port was impossible. When the intrathecal catheter was removed, we observed that the side hole and lumen of the catheter was plugged.

Effective treatments for pain in the older patient

By 2050, the number of older persons across the globe will exceed the number of younger people for the first time in history. Chronic conditions, especially pain, will rise in prevalence as the population ages. Controlling pain in this unique subset of the population demands careful attention to pharmacokinetic and pharmacodynamic factors and their specific impact on pharmacotherapies, relevant complementary and alternative medicine therapies, and interventional strategies.

Intracerebroventricular enzyme infusion corrects central nervous system pathology and dysfunction in a mouse model of metachromatic leukodystrophy

Arylsulfatase A (ASA) catalyzes the desulfation of sulfatide, a major lipid component of myelin. Inherited functional deficiencies of ASA cause the lysosomal storage disease (LSD) metachromatic leukodystrophy (MLD), which is characterized by intralysosomal accumulation of sulfatide, progressive neurological symptoms and early death. Enzyme replacement therapy (ERT) using intravenous injection of active enzyme is a treatment option for many LSDs as exogenous lysosomal enzymes are delivered to lysosomes of patient's cells via receptor-mediated endocytosis. Efficient treatment of MLD and other LSDs with central nervous system (CNS) involvement is, however, hampered by the blood-brain barrier (BBB), which limits transfer of therapeutic enzymes from the circulation to the brain parenchyma. To bypass the BBB, we infused recombinant human ASA (rhASA) by implanted miniature pumps into the cerebrospinal fluid (CSF) of a conventional and a novel, genetically aggravated ASA knockout mouse model of MLD. rhASA continuously delivered to the lateral ventricle for 4 weeks penetrated the brain parenchyma and was targeted to the lysosomes of brain cells. Histological analysis revealed complete reversal of lysosomal storage in the infused hemisphere. rhASA concentrations and sulfatide clearance declined with increasing distance from the infusion site. Correction of the ataxic gait indicated reversal of central nervous system dysfunctions. The profound histopathological and functional improvements, the requirement of low enzyme doses and the absence of immunological side effects suggest intracerebroventricular ERT to be a promising treatment option for MLD and other LSDs with prevailing CNS disease.

In vivo study of flow-rate accuracy of the MedStream Programmable Infusion System

OBJECTIVE

  Flow-rate accuracy and precision are important parameters to optimizing the efficacy of programmable intrathecal (IT) infusion pump delivery systems. Current programmable IT pumps are accurate within ±14.5% of their programmed infusion rate when assessed under ideal environmental conditions and specific flow-rate settings in vitro. We assessed the flow-rate accuracy of a novel programmable pump system across its entire flow-rate range under typical conditions in sheep (in vivo) and nominal conditions in vitro.

MATERIALS AND METHODS

  The flow-rate accuracy of the MedStream Programmable Pump was assessed in both the in vivo and in vitro settings. In vivo flow-rate accuracy was assessed in 16 sheep at various flow-rates (producing 90 flow intervals) more than 90 ± 3 days. Pumps were then explanted, re-sterilized and in vitro flow-rate accuracy was assessed at 37°C and 1013 mBar (80 flow intervals).

RESULTS

  In vivo (sheep body temperatures 38.1°C-39.8°C), mean ± SD flow-rate error was 9.32% ± 9.27% and mean ± SD leak-rate was 0.028 ± 0.08 mL/day. Following explantation, mean in vitro flow-rate error and leak-rate were -1.05% ± 2.55% and 0.003 ± 0.004 mL/day (37°C, 1013 mBar), respectively.

CONCLUSIONS

  The MedStream Programmable Pump demonstrated high flow-rate accuracy when tested in vivo and in vitro at normal body temperature and environmental pressure as well as when tested in vivo at variable sheep body temperature. The flow-rate accuracy of the MedStream Programmable Pump across its flow-rate range, compares favorably to the accuracy of current clinically utilized programmable IT infusion pumps reported at specific flow-rate settings and conditions.

Intrathecal bupivacaine for head and neck pain

Direct central nervous system (CNS) analgesic delivery is a useful option when more traditional means of dealing with chronic pain fail. Solutions containing local anesthetic have been effective in certain disease states, particularly in patients suffering from intractable head and neck pain. This review discusses historical aspects of CNS drug delivery and the role of intrathecal bupivacaine-containing solutions in refractory head and neck pain patients.

Antisense correction of SMN2 splicing in the CNS rescues necrosis in a type III SMA mouse model

Increasing survival of motor neuron 2, centromeric (SMN2) exon 7 inclusion to express more full-length SMN protein in motor neurons is a promising approach to treat spinal muscular atrophy (SMA), a genetic neurodegenerative disease. Previously, we identified a potent 2'-O-(2-methoxyethyl) (MOE) phosphorothioate-modified antisense oligonucleotide (ASO) that blocks an SMN2 intronic splicing silencer element and efficiently promotes exon 7 inclusion in transgenic mouse peripheral tissues after systemic administration. Here we address its efficacy in the spinal cord--a prerequisite for disease treatment--and its ability to rescue a mild SMA mouse model that develops tail and ear necrosis, resembling the distal tissue necrosis reported in some SMA infants. Using a micro-osmotic pump, we directly infused the ASO into a lateral cerebral ventricle in adult mice expressing a human SMN2 transgene; the ASO gave a robust and long-lasting increase in SMN2 exon 7 inclusion measured at both the mRNA and protein levels in spinal cord motor neurons. A single embryonic or neonatal intracerebroventricular ASO injection strikingly rescued the tail and ear necrosis in SMA mice. We conclude that this MOE ASO is a promising drug candidate for SMA therapy, and, more generally, that ASOs can be used to efficiently redirect alternative splicing of target genes in the CNS.