Hyperthermia, rhabdomyolysis, and disseminated intravascular coagulation associated with baclofen pump catheter failure

Assessment of Health Care Costs and Total Baclofen Use Associated With Targeted Drug Delivery for Spasticity

BACKGROUND

Chronic spasticity causes significant impairment and financial burden. Oral baclofen, the first-line therapy, can have intolerable, dose-dependent side effects. Targeted drug delivery (TDD) through intrathecal baclofen delivers smaller amounts of baclofen into the thecal sac via an implanted infusion system. However, the health care resource utilization of patients with spasticity receiving TDD has not been studied extensively.

MATERIALS AND METHODS

Adult patients who received TDD for spasticity between 2009 and 2017 were identified using the IBM MarketScan® data bases. Patients' use of oral baclofen and health care costs were examined at baseline (one year before implantation) and three years after implantation. A multivariable regression model using the generalized estimating equations method and a log link function was used to compare postimplantation costs with those at baseline.

RESULTS

The study identified 771 patients with TDD for medication analysis and 576 for cost analysis. At baseline, the median costs were $39,326 (interquartile range [IQR]: $19,526-$80,679), which increased to $75,728 (IQR: $44,199-$122,676) in year 1, decreased to $27,160 (IQR: $11,896-$62,427) in year 2, and increased slightly to $28,008 (IQR: $11,771-$61,885) in year 3. In multivariable analysis, the cost was 47% higher than at baseline (cost ratio [CR] 1.47, 95% CI: 1.32-1.63) in year 1 but was 25% lower (CR 0.75, 95% CI: 0.66-0.86) in year 2 and 32% lower (CR 0.68, 95% CI: 0.59-0.79) in year 3. Before implant, 58% of patients took oral baclofen, which decreased to 24% by year 3. The median daily baclofen dose decreased from 61.8 mg (IQR: 40-86.4) before TDD to 32.8 mg (IQR: 30-65.7) three years later.

CONCLUSIONS

Our findings indicate that patients who undergo TDD use less oral baclofen, potentially reducing the risk of side effects. Although total health care costs increased immediately after TDD, most likely owing to device and implantation costs, they decreased below baseline after one year. The costs of TDD reach cost neutrality approximately three years after implant, indicating its potential for long-term cost savings.

Severe Case of Oral Baclofen Withdrawal Resulting in Mechanical Ventilation

Abrupt baclofen withdrawal may be life-threatening with varied neuropsychiatric manifestations. We present a case of baclofen withdrawal necessitating intubation. A 58-year-old female with a history of undiagnosed muscle spasticity presented with worsening extremities tremors, paresthesia, and weakness for 2 days. Initial vitals included temperature 103 F, tachycardia, hypertension, and tachypnea. Examination revealed coarse tremors of all extremities. Inflammatory markers, blood, and urine culture were negative. Head and spine imaging were non-diagnostic. Meningitis and seizure were ruled out. She continued worsening with hallucinations, hyperpyrexia, ocular clonus, and profound muscle rigidity. The patient was intubated for respiratory distress and transferred to intensive care unit (ICU). Further history revealed running out of oral baclofen 3 days ago. Baclofen was restarted with symptomatic improvement. The patient was extubated after 2 days and discharged to a rehabilitation facility. Oral or intrathecal baclofen is thought to inhibit spinal nerves reducing muscle spasm and pain. Abrupt stoppage causes activation of dopamine and noradrenergic receptors causing muscle spasms, tremors, hyperpyrexia, delusions, hallucination, and delirium. Severe cases can mimic meningoencephalitis, seizure disorder, or neuroleptic malignant syndrome. Symptoms usually develop in 1 to 3 days of cessation and can be life-threatening if unrecognized timely. Treatment includes supportive therapy, re-administration of baclofen, or use of benzodiazepines, propofol, dexmedetomidine; however, no specific guidelines have been established. To the knowledge of the authors, this is the first case of oral baclofen withdrawal requiring intubation. We found only 3 reported cases of intrathecal baclofen withdrawal necessitating intubation.

Priapism after spinal cord injury - a case report and review of the literature

Involuntary unwanted erections are extremely rare after spinal cord injury (SCI). A sudden loss of sympathetic tone to the pelvic vasculature following SCI causes an increase in the parasympathetic tone and uncontrolled arterial blood flow into the penile sinusoidal spaces. When occurring immediately after an acute SCI, it is generally self-limiting and settles within a few hours. In contrast, recurrent, unwanted erections in patients with chronic SCI are more unpredictable in frequency and duration and may require treatment. We present a case of recurrent involuntary unwanted erections in a patient with chronic SCI after a stab wound to his neck and review the pathophysiology and available management options.

Baclofen therapeutics, toxicity, and withdrawal: A narrative review

Baclofen is an effective therapeutic for the treatment of spasticity related to multiple sclerosis, spinal cord injuries, and other spinal cord pathologies. It has been increasingly used off-label for the management of several disorders, including musculoskeletal pain, gastroesophageal reflux disease, and alcohol use disorder. Baclofen therapy is associated with potential complications, including life-threatening toxicity and withdrawal syndrome. These disorders require prompt recognition and a high index of suspicion. While these complications can develop following administration of either oral or intrathecal baclofen, the risk is greater with the intrathecal route. The management of baclofen toxicity is largely supportive while baclofen withdrawal syndrome is most effectively treated with re-initiation or supplementation of baclofen dosing. Administration of other pharmacologic adjuncts may be required to effectively treat associated withdrawal symptoms. This narrative review provides an overview of the historical and emerging uses of baclofen, offers practical dosing recommendations for both oral and intrathecal routes of administration, and reviews the diagnosis and management of both baclofen toxicity and withdrawal.

Principles of Pharmacotherapy of Seizures and Status Epilepticus

Status epilepticus is a neurological emergency with an outcome that is highly associated with the initial pharmacotherapy management that must be administered in a timely fashion. Beyond first-line therapy of status epilepticus, treatment is not guided by robust evidence. Optimal pharmacotherapy selection for individual patients is essential in the management of seizures and status epilepticus with careful evaluation of pharmacokinetic and pharmacodynamic factors. With the addition of newer antiseizure agents to the market, understanding their role in the management of status epilepticus is critical. Etiology-guided therapy should be considered in certain patients with drug-induced seizures, alcohol withdrawal, or autoimmune encephalitis. Some patient populations warrant special consideration, such as pediatric, pregnant, elderly, and the critically ill. Seizure prophylaxis is indicated in select patients with acute neurological injury and should be limited to the acute postinjury period.

The Minimum Data Set: An Opportunity to Improve Spasticity Screening

Spasticity is a common movement disorder that arises from trauma or disease affecting the central nervous system. Untreated spasticity can result in limitations in completing activities of daily living, painful limb contractures, and other conditions associated with loss of mobility. In the long-term care setting, this treatable condition is prevalent, yet often unrecognized likely because of a lack of spasticity-trained practitioners. A recently published spasticity referral tool holds promise for addressing the underdiagnosis of spasticity in the long-term care population. The Minimum Data Set (MDS) would be an ideal mechanism for increasing the diagnosis and treatment of spasticity because it is a government-directed comprehensive screening tool that informs care plans for all residents residing in federally funded long-term care facilities. The MDS could easily integrate the published referral assessment to record the presence of spastic postures and muscle rigidity. We propose expanding the MDS to include 3 questions related to spasticity to improve the recognition and treatment of this prevalent and treatable condition.

Pain Management in Multiple Sclerosis: a Review of Available Treatment Options

PURPOSE OF REVIEW

Multiple Sclerosis (MS) is a chronic autoimmune disease with no curative treatment available. While recent years have ushered in many effective new disease-modifying therapies for MS, they have not obviated the need for symptomatic treatments for MS-related pain. In this review, we discuss available approaches to control pain, which is one of the most common complaints MS patients have.

RECENT FINDINGS

The most recent research in this topic is directed towards non-pharmacologic interventions including water exercises, yoga and cannabis. More trials are being conducted on neuromodulation for MS-related neuropathic pain, including transcutaneous electrical nerve stimulation (TENS) and transcranial direct current stimulation (tDCS). Pain control for MS patients is challenging, considering the progressive and relapsing remitting nature of the disease, however, it is a very important aspect of it's management, as it improves mobility, exercise tolerance, concomitant depression and overall quality of life. Future research should focus on the use of neuromodulation in controlling MS pain.

Plain radiography in patients treated with intrathecal drug delivery using an implantable pump device

OBJECTIVES

Intrathecal drug administration using an implanted pump system is well established in intractable spasticity and pain. However, despite continuous advancements in manufacturing technology, adverse events related to the pump and catheter still occur. Most of them, such as migration, damage, disconnection and occlusion, are related to the spinal catheter. The aim of this overview is to update radiologists on how plain radiography of the implanted delivery system for intrathecal drug administration should be interpreted and to increase awareness for the need of urgent and timely multidisciplinary troubleshooting.

METHODS

Plain radiographic images of patients treated with intrathecal drug administration using an implantable drug delivery system were analysed in a multidisciplinary setting at our (university) referral centre for complications in intrathecal drug administration.

RESULTS

Examples of catheter-related adverse events are described and a proposal is made for stepwise interpretation of standard plain radiographic images.

CONCLUSIONS

Plain radiological images are the mainstay for the diagnosis of catheter-related adverse events in intrathecal drug delivery. Radiologists play an important role in an early diagnosis. An awareness of abnormal radiological findings seems important to avoid a life-threatening withdrawal syndrome.

TEACHING POINTS

• Untimely cessation of intrathecal drug delivery can lead to a life-threatening withdrawal syndrome. • Initially mild symptoms can lead to an exacerbation of a withdrawal syndrome. • Most intrathecal catheter-related problems are visible on plain radiography. • Common causes of catheter problems are migration, lacerations, occlusion and disconnection. • Knowledge on implanted intrathecal catheters is crucial for interpretation of plain radiography.

Perioperative complications associated with spine surgery in patients with established spinal cord injury

BACKGROUND CONTEXT

Only a small percentage of patients with spinal cord injury (SCI) require consideration for reconstructive surgery after their initial injury. For those who do, perioperative complications can be frequent and significant. There has been very little published literature examining treatment of these patients and essentially nothing to guide the surgeon in perioperative decision making and management.

PURPOSE

To identify some of the common challenges associated with surgery in this patient population and review the literature to highlight the perioperative concerns in patients with chronic SCI.

STUDY DESIGN

Review article.

METHODS

A primary PubMed literature search was performed and reviewed for patients with chronic SCI with emphasis on the complications and difficulties encountered during surgical treatment of patients with chronic SCI.

RESULTS

For those who do proceed with surgery in this patient population, preoperative nutrition, bone density, and skin should be evaluated and optimized. Preoperative inferior vena cava filters should be considered. The integrity of the reconstruction will be extensively challenged. In addition, augmented fixation and bracing should be contemplated.

CONCLUSIONS

Patients with chronic SCI who require spinal reconstruction provide many unique challenges. Indications for surgery must be strong as perioperative complications can be frequent and long-term outcomes unpredictable. Close monitoring for postoperative complications is essential.

Dexmedetomidine for acute baclofen withdrawal

BACKGROUND

Intrathecal baclofen is widely accepted as a treatment option for severe spasticity through its γ-Aminobutyric acid-B (GABAB ) agonist properties. Abrupt cessation can lead to severe and life-threatening withdrawal characterized by altered mental status, autonomic dysreflexia, rigidity, and seizures. This symptomatic presentation is similar to alcohol withdrawal, which is mediated by modification of GABAA expression. Use of the α2-adrenergic agonist dexmedetomidine for the treatment of ethanol withdrawal has been widely reported, raising the question of its potential role in baclofen withdrawal. We present a case of the successful treatment of acute severe baclofen withdrawal with a dexmedetomidine infusion.

METHODS

A 15-year-old patient with spastic quadriparesis and cerebral palsy underwent unexpected removal of his baclofen pump due to an infection that was encountered during a planned pump revision. Following removal, he was placed on high dose enteral baclofen every 6 h. Despite further benzodiazepine supplementation, he had progressive hemodynamic instability, severe rebound spasticity, and intermittent spontaneous clonus consistent with baclofen withdrawal. A dexmedetomidine infusion was titrated to a peak dose of 16 mcg per hour with successful treatment of withdrawal symptoms.

RESULTS

The patient became normotensive without tachycardia. Tone and agitation improved.

CONCLUSION

Dexmedetomidine is to our knowledge a previously unreported option for treatment of acute severe baclofen withdrawal. We report a case of safe and efficacious use in a patient with spastic quadriparesis on chronic intrathecal baclofen. Scientifically rigorous comparison with other options remains to be performed.

Baclofen pump catheter leakage after migration of the abdominal catheter in a pediatric patient with spasticity

The authors report an unusual case of intrathecal baclofen withdrawal due to the perforation and subsequent leakage of a baclofen pump catheter in a patient with spastic cerebral palsy. A 15-year-old boy underwent an uncomplicated placement of an intrathecal baclofen pump for the treatment of spasticity due to cerebral palsy. After excellent control of symptoms for 3 years, the patient presented to the emergency department with increasing tremors following a refill of his baclofen pump. Initial evaluation consisted of radiographs of the pump and catheter, which appeared normal, and a successful aspiration of CSF from the pump's side port. A CT dye study revealed a portion of the catheter directly overlying the refill port and extravasation of radiopaque dye into the subfascial pocket anterior to the pump. During subsequent revision surgery, a small puncture hole in the catheter was seen to be leaking the drug. The likely cause of the puncture was an inadvertent perforation of the catheter by a needle during the refilling of the pump. This case report highlights a unique complication in a patient with an intrathecal baclofen pump. Physicians caring for these patients should be aware of this rare yet potential complication in patients presenting with baclofen withdrawal symptoms.

Perioperative temperature elevation: not all hyperthermia is malignant hyperthermia

OBJECTIVES

The objective of this review is to assist the readers, anesthesiologists, intensivists, and emergency physicians in making a more accurate diagnosis of perioperative fever or hyperthermia and subsequently choose the proper course of treatment.

AIM

To identify the many sources of perioperative fever and after a more accurate differential diagnosis, select appropriate treatment options. Most anesthesiologists, intensivists, and emergency physicians are not familiar with an expansive differential of perioperative fever. This article attempts to expose these physicians to that differential diagnosis.

BACKGROUND

Much of the medical literature has anecdotal reports, small case series, or limited reviews of the possible sources of hyperthermia or fever. This is especially true of the anesthesia literature.

RESULTS

A literature search was performed which identified many possible common and uncommon sources of fever. Some of these sources are quite relevant to the anesthesiologist. Other sources had potential relevance in obscure cases.

Long-term outcomes of continuous intrathecal baclofen infusion for treatment of spasticity: a prospective multicenter follow-up study

Long-term outcomes of 115 patients treated with continuous intrathecal baclofen infusion are reported. A prospective follow-up study was conducted in eight centers. Patients were followed up over a 12-month period. The follow-up scores on the three spasticity scales (Ashworth, spasm, and clonus scales) were significantly lower at every follow-up visit in comparison to the intake score, except for the clonus scale scores at 12 months. Improvements in health-related quality of life (EQ-5D) and functionality (SIP-68, functional independence measure) were small and nonsignificant. A significant reduction in severity of self-reported personal problems rating scale was observed. Sixty-six patients had no adverse events. Types of adverse events reported were wound complications (22%), catheter problems (36%), cerebrospinal fluid leakage (25%), and other complications (17%). Intrathecal baclofen reduces spasticity and severity of patient-reported problems but its effect on quality of life and functionality is less apparent. Improvements are desired in selection criteria, design of spinal catheters, and outcome scales.

A Review of Spasticity Treatments: Pharmacological and Interventional Approaches

Spasticity is a velocity-dependent increase in muscle tone and uncontrolled, repetitive, involuntary contractions of skeletal muscles. Spasticity presents as upper motor neuron symptoms in patients with central nervous system pathology such as stroke, spinal cord injury, brain injury, or multiple sclerosis. As a result, a patient can have significant pain and limited mobility, which can lead to decreased quality of life and difficulty maintaining personal care. In this article we discuss mechanisms, indications, efficacy, and side effects of the most accepted current treatments. Currently available treatment options include oral medications and interventional procedures. Oral medications comprise centrally acting agents, such as baclofen, clonidine, and tizanidine, as well as anticonvulsants such as benzodiazepines and gabapentin and peripherally acting dantrolene. Interventional procedures include focal injections of botulinum toxin, phenol or alcohol, and an intrathecal baclofen pump. Surgical treatments include selective dorsal rhizotomy and neurectomy. We found that there are several treatments available with data to support their use, but many still need further research to prove their efficacy and develop optimal utilization.

Subdural catheter migration may lead to baclofen pump dysfunction

OBJECTIVES

To report an unusual cause of intrathecal drug delivery failure in baclofen pump device.

STUDY DESIGN

A case report of an SCI patient treated with intrathecal baclofen, presenting a drug withdrawal.

SETTING

Regional spinal cord injuries centre in Geneva (Switzerland).

METHODS

We present a case of a 38-year-old male with complete T9 spastic paraplegia for 15 years, treated with intrathecal baclofen for 11 years. He recently presented to our centre with a spastic hypertonic episode, associated with rhabdomyolysis.

RESULTS

Standard investigations were unrevealing. However, a CT scan performed after injecting a radio-opaque solution by the side port of the pump, showed an unexpected catheter migration into the subdural space. Surgical revision reversed withdrawal symptoms.

CONCLUSIONS

Subdural catheter migration must be considered in the differential diagnosis of intrathecal drug delivery system failures. We recommend the use of the CT scan after contrast injection, to detect the localization of the distal catheter tip and confirm the normal diffusion into the subarachnoid space.

Accidental intoxication with 60 mg intrathecal baclofen: survived

BACKGROUND

Intrathecal baclofen (ITB) is an effective and well-tolerated treatment for patients with severe spasticity. Intoxications are rare and usually iatrogenic, with reported intrathecal boluses varying between 0.050 and 30 mg.

METHODS

We here report the case of a 47-year-old woman with severe spastic paraplegia due to multiple sclerosis who, during a routine filling procedure, accidentally received a bolus of 60 mg ITB because of injection into the side-port instead of the reservoir of her ITB pump (Archimedes(®), Codman, Germany).

RESULTS

After a short period of dizziness, she lost consciousness and stopped breathing. She was immediately intubated, mechanically ventilated, and admitted to the intensive care unit. As specific treatment, she received cerebrospinal fluid drainage through a newly implanted lumbar catheter. A series of generalized and complex partial seizures were treated with levetiracetam and lacosamide. Acute autonomic dysfunction with episodic arterial hypo- and hypertensions was controlled by catecholamines and clonidine, respectively. Recurrent hyperthermia, however, responded neither to drugs nor to physical treatment. After 3 weeks, the patient was discharged without any relevant new neurologic signs or symptoms.

CONCLUSIONS

This case demonstrates that even excessive doses of ITB can let the patients survive without sequelae if treated promptly and offensively. A pertinent problem during detoxification is the question of when to restart ITB to avoid drug withdrawal.

Management of acute overdose or withdrawal state in intrathecal baclofen therapy

STUDY DESIGN

Individuals who are treated with intrathecal Baclofen (ITB) pump delivery system for intractable spasticity can suffer from severe morbidity as a result of acute overdose or withdrawal of ITB, which can also be life threatening. Current literature has a number of single case studies with different approaches to the management in such states.

OBJECTIVES

The aim of this article is to consolidate available evidence and develop treatment pathways for acute ITB overdose and withdrawal states.

METHODS

We searched MEDLINE, EMBASE, CINAHL and the Cochrane Library databases using the keywords 'intrathecal', 'baclofen', 'withdrawal', 'overdose' to identify studies (published up to December 2010) that focused on presentation or treatment of acute overdose and withdrawal state in ITB therapy. Only original articles in English involving adult population were included.

RESULTS

Initial search revealed 130 articles. After reading the abstract, 13 studies on ITB overdose and 23 studies on ITB withdrawal were deemed suitable for inclusion. All studies were either single-case studies or case series.

CONCLUSION

Acute ITB overdose is managed with immediate cessation of baclofen delivery through the system, reducing the baclofen load by cerebrospinal fluid aspiration and by providing supportive treatment in an intensive care setting. There is no specific antidote for reversing overdose symptoms. Acute ITB withdrawal is managed by restoring the delivery of ITB, providing supportive care in an intensive care setting and using drugs like low dose propofol or benzodiazepines in selected cases. Early involvement of ITB physicians is strongly recommended.

Acute intrathecal baclofen withdrawal: a brief review of treatment options

BACKGROUND

Acute baclofen toxicity and withdrawal can present with a constellation of symptoms making differentiation between these two entities and other potential diagnoses challenging. Baclofen withdrawal is associated with numerous complications which may require neurocritical care expertise such as respiratory failure, refractory seizures, delirium, and blood pressure lability.

METHODS

Case report and literature review.

RESULTS

This case report discusses a case of intrathecal baclofen (ITB) withdrawal, focusing on the differential diagnosis for acute baclofen withdrawal and reviews the various options that exist to treat the symptoms of acute baclofen withdrawal such as benzodiazepines, propofol, skeletal muscle relaxants, and tizanidine.

CONCLUSIONS

Critical care practitioners should be prepared to treat this potentially devastating and often refractory complication of ITB therapy.

Review: Procedure- and Device-Related Complications of Intrathecal Baclofen Administration for Management of Adult Muscle Hypertonia: A Review

Background. Intrathecal baclofen (ITB) effectively reduces muscle hypertonia; however, associated complications influence its utility and acceptance. Objective. To systematically review the literature on procedure- and device-related complications associated with ITB infusion therapy for adult muscle hypertonia of spinal or cerebral origin. Methods. The authors searched the PubMed database for full-length articles published in English that reported ITB-associated complications in adults. Of 147 articles retrieved, 32 full-length manuscripts and 10 case reports were reviewed in detail. Results. Overall, 558 complications were reported after 1362 pump implants (0.41 per implant). Methods for characterizing complications varied greatly between studies, as did complication rates, ranging from 0 to 2.24 per implant. Of the 558 complications, 148 (27%) were related to surgical procedures, 39 (7%) to pump problems, and 369 (66%) to catheter malfunctions. The overall complication rate was higher for studies that followed patients for more than 18 months on average (mean 0.56/implant) versus studies with shorter follow-up (0.23/implant, P < .05). Although correlation between the number of implants and the number of complications was significant ( r = .58), the goodness of linear fit was poor because of clusters with varied complication rates. Conclusions. Catheter problems are relatively common and more frequent than pump or surgical procedure complications after ITB pump implantation. Higher complication rates should be expected in centers that follow patients for a longer period of time. Standardized data collection and complication-reporting procedures along with appropriate training should be implemented in centers offering ITB treatment for management of muscle hypertonia.

Intrathecal baclofen therapy: indications, pharmacology, surgical implant, and efficacy

Intrathecal baclofen (ITB) therapy is an option for those in whom predominantly lower extremity spasticity is severe, problematic, and intractable to oral doses of medications and/or focal treatment. When delivered to the lumbar area, ITB avoids high concentrations from reaching the brain (4:1 ratio lumbar to brain cisterns). A screening test dose is done prior to implanting the pump via a lumbar puncture with 50 microg baclofen, working up to 100 microg if necessary. There are two [2] types of pumps. The electronic programmable type has the advantage of flexibility of dosing and frequent change of doses for fine-tuning the patient's optimal dose. The mechanical constant flow type has the advantages of (1) being gas driven and not needing battery replacement, and (2) not needing a programmer to refill, thus allowing geographically removed patients to benefit from ITB. Catheter complications are reduced by using a shallow-angle paramedian oblique insertion to the spine, and meticulous anchoring of the catheter. Threading the catheter to T6/7 rather than the traditional T10/11 can allow upper limb relief also. Long term efficacy is excellent, although catheter complications are frequent. and if not recognized and treated, can lead to significant effects of withdrawal of baclofen.

Intravenous diazepam infusion in the management of planned intrathecal baclofen withdrawal

Intrathecal baclofen is used in the management of spasticity associated with cerebral palsy (CP). Sudden cessation of intrathecal baclofen may give rise to the potentially life-threatening baclofen withdrawal syndrome. We report three cases in which intravenous diazepam is used effectively in the management of planned intrathecal withdrawal. All three patients had CP. In the first patient, a 19-year-old male with quadriplegia, the intrathecal catheter had to be removed. The other two patients, an 11-year-old female with diplegia and a 16-year-old male with quadriplegia, both required the entire device to be removed. The purpose of this case report is to illustrate the potential management for elective cases in a similar situation.

Conduite à tenir devant une recrudescence de spasticité chez un patient porteur d'une pompe à baclofène

INTRODUCTION

The incidence of complications after baclofen pump implantation is relatively high. Diagnosis of these complications can be difficult. A diagnostic tree would be a useful tool in cases of suspected malfunctioning of the intrathecal bacolfen infusion system and would standardise the diagnostic procedure.

METHOD

From results in the literature and the experience of our department, we designed a diagnostic tree to aid in finding the cause of a recrudescence of spasticity in patients with implanted baclofen pumps.

RESULTS

The potential causes of recrudescence of spasticity are described and a diagnostic pathway is proposed.

DISCUSSION

The aim of a standardised hierarchical method of diagnosis of the cause of increased spasticity in patients with intrathecal baclofen pumps is to gain time in the diagnosis and treatment. Such diagnosis should improve patient care by permitting rapid restoration of an adequate level of baclofen infusion as well as decreasing the length of hospital stay and, as a consequence, the cost relating to malfunctioning pumps.

Selection of treatment modalities in children with spastic cerebral palsy

The purpose of this report was to outline the various options currently used for treatment of spastic cerebral palsy (CP) and to discuss factors involved in selecting the appropriate treatment modalities for the individual child. In a review of the literature and his personal observations, the author presents an outline of treatment options and the criteria for using each. Therapeutic options include the following: physiotherapy; occupational therapy; oral spasmolytic and antidystonic drugs; botulinum toxin injections; orthopedic procedures; continuous infusion of intrathecal baclofen (ITB); selective dorsal rhizotomy (SDR); and selective peripheral neurotomy. The most commonly used neurosurgical procedures are ITB pump placement and SDR, and these are discussed in the most detail. The author's personal schema for assessment of the child to determine the nature of the hypertonia, the impact of the hypertonia, and the appropriate therapeutic intervention is presented. There are factors that help guide the optimal treatment modalities for the child with spastic CP. The treatment of these children is optimized in the setting of a multidisciplinary team.

Prolonged intrathecal baclofen withdrawal syndrome. Case report and discussion of current therapeutic management

The authors describe a patient who experienced a prolonged course of intrathecal baclofen withdrawal syndrome after removal of an implantable baclofen pump for treatment of pump infection and meningitis. The current literature outlines management options for the acute management of this syndrome. In this report the authors discuss the long-term presentation of this syndrome and suggest a treatment strategy for management of the syndrome. A 37-year-old man who presented with a baclofen pump infection and meningitis experienced acute onset of intrathecal baclofen withdrawal syndrome 12 hours after the pump had been surgically removed. The patient's symptoms evolved into a severe, treatment-refractory withdrawal syndrome lasting longer than 1 month. Oral baclofen replacement with adjunctive administration of parenteral gamma-aminobutyric acid agonists only served to stabilize the patient's critical condition throughout his hospital course. Replacement of the baclofen pump and restoration of intrathecal delivery of the medication was necessary to trigger the patient's dramatic recovery and complete reversal of the withdrawal syndrome within approximately 48 hours. These findings indicate that a more direct method of treating infected baclofen pumps than immediate surgical removal is necessary to prevent the onset of intrathecal baclofen withdrawal syndrome. Various options for preventing the onset of the syndrome while simultaneously treating the infection are discussed.

Intrathecal baclofen withdrawal syndrome caused by low residual volume in the pump reservoir: A report of 2 cases

Intrathecal baclofen (ITB) is an effective treatment for spasticity caused by spinal or cerebral pathologies. Severe withdrawal symptoms can result, however, if ITB is abruptly withdrawn as a result of equipment malfunctions or human error. We describe 2 cases of severe ITB withdrawal syndrome. In the first case, the symptoms appeared 5 months after pump placement, when residual volume was 2.0 mL; in the second case, symptoms appeared 2 months after the replacement of a new pump, when residual volume was 0.9 mL. In both cases, there was no evidence of system malfunction or human error. The syndrome occurred from up to 72 hours before the scheduled refilling procedure, and the residual volume in the Medtronic SynchroMed EL pump reservoir was either at, or significantly lower than, the recommended 2 mL. These cases suggest that the SynchroMed EL pump reservoir should be refilled, to avoid potentially serious consequences, when the residual volume is not lower than 3 mL by programming the alarm to sound at a volume larger than the recommended 2 mL.

Intrathecal baclofen withdrawal: emergent recognition and management

Patients with severe spasticity are frequently encountered in the pediatric emergency department. Intrathecal baclofen therapy is being used increasingly to treat these patients. The purpose of this case series is to illustrate the importance of early recognition and treatment of intrathecal baclofen withdrawal, a potentially life-threatening complication of intrathecal baclofen therapy. Four cases of intrathecal baclofen withdrawal are presented.

A benefit-risk assessment of baclofen in severe spinal spasticity

Baclofen is used for treatment of the spasticity of spinal origin that is a common sequela of spinal cord injury and multiple sclerosis; spasticity occurs in about 50% of patients affected by these disorders. In open-label studies of oral baclofen, the drug improved spasticity in 70-87% of patients; additionally, improvement in spasms was reported in 75-96% of patients. In double-blind, crossover, placebo-controlled trials, baclofen was reported to be effective, producing statistically significant improvements in spasticity. Tizanidine is the antispasticity drug that has been most widely compared with oral baclofen; studies have generally found the two drugs to have equivalent efficacy. However, tizanidine has better tolerability, in particular weakness was reported to be occur less frequently with tizanidine than with baclofen. The main adverse effects of oral baclofen include: sedation or somnolence, excessive weakness, vertigo and psychological disturbances. The incidence of adverse effects is reported to range from 10% to 75%. The majority of adverse effects are not severe; most are dose related, transient and/or reversible. The main risks of oral baclofen administration are related to withdrawal: seizures, psychic symptoms and hyperthermia can occur. These symptoms improve after the reintroduction of baclofen, usually without sequelae. When not related to withdrawal; these symptoms mainly present in patients with brain damage and in the elderly. The limited data on baclofen toxicity in patients with renal disease suggest that administration of the drug in these persons may carry an unnecessarily high risk. Intrathecal baclofen is indicated for use in patients with spasticity of spinal origin unresponsive to treatment with maximum doses of oral baclofen, tizanidine and/or dantrolene. The benefits of continuous intrathecal baclofen infusion have been demonstrated: >80% and >65% of patients have improvement in tone and spasms, respectively. The main risks of intrathecal baclofen infusion are symptoms related to overdose or withdrawal; the latter is more important because of the associated severe effects on clinical status and the possibility of death, but it is responsive to rapid treatment. Overdose primarily arises from drug test doses or human error during refill and programming of the pump, and withdrawal most commonly occurs as a result of a problem with the delivery system. Since the adverse consequences do not exceed the benefits of oral and intrathecal baclofen for patients with spinal spasticity, the benefit/risk assessment is favourable.

Treatment of spasticity with intrathecal Baclofen administration: long-term follow-up, review of 40 patients

STUDY DESIGN

Case series of a consecutive sample. Retrospective audit.

OBJECTIVE

To analyze the long-term safety and efficacy of intrathecal baclofen (ITB), and technical incidents.

SETTING

Neurosurgical and Physical Medicine Departments of two university hospitals in western France.

METHODS

The medical records of 40 patients who underwent ITB pump placement for the treatment of severe chronic spasticity were reviewed. Patients were eligible independently of the origin of the spasticity (spinal cord origin 33, brain damage 8). They underwent a final assessment with clinical examination and questionnaire in 2001. Ashworth scale scores were assessed, patient satisfaction was rated on a visual analog scale (VAS), functional independence before and after treatment was classified as bed-ridden, wheelchair dependent or ambulant, and the frequency and nature of complications were noted.

RESULTS

The average follow-up period was of 4 years. The average Ashworth score at the final assessment was 1.8+/-0.6. Average patients satisfaction was 7.4/10+/-2.21 on VAS. In all, 85% would have undergone the procedure again if they had to make the decision. In 85% of the cases the ambulation status was unchanged. Technical incidents occurred at least once in 37% of the patients (due to the catheter in 58% and to the pump in 42%). They included catheter disconnections (4), migration (4), kinks (3), obstruction (3), development of fibrosis (3), disconnection of pump reservoir (2), porosity of pump membrane (2), unexplained pump dysfunction (4) leakage, and subcutaneous collection (5). Severe pharmacological side effects requiring transfer to intensive care unit occurred in 12% of cases, 80% of which were directly related to pump refill procedures.

CONCLUSION

ITB remained effective in the long term and patients were satisfied. Nevertheless, complications were frequent, involving mainly the catheters, which would require further technical improvements.

Intrathecal baclofen withdrawal syndrome- a life-threatening complication of baclofen pump: a case report

Background

Intrathecal baclofen pump has been used effectively with increasing frequency in patients with severe spasticity, particularly for those patients who are unresponsive to conservative pharmacotherapy or develop intolerable side effects at therapeutic doses of oral baclofen. Drowsiness, nausea, headache, muscle weakness, light-headedness and return of pretreatment spasticity can be caused by intrathecal pump delivering an incorrect dose of baclofen. Intrathecal baclofen withdrawal syndrome is a very rare, potentially life-threatening complication of baclofen pump caused by an abrupt cessation of intrathecal baclofen.

Case presentation

A 24-year-old man with a past medical history of cerebral palsy and spastic quadriparesis developed hyperthermia, disseminated intravascular coagulation, rhabdomyolysis, acute renal failure and multisystem organ failure leading to a full-blown intrathecal baclofen withdrawal syndrome. Intrathecal baclofen pump analysis revealed that it was stopped due to some programming error. He was treated effectively with supportive care, high-dose benzodiazepines and reinstitution of baclofen pump.

Conclusion

The episodes of intrathecal baclofen withdrawal syndrome are mostly caused by preventable human errors or pump malfunction. Educating patients and their caregivers about the syndrome, and regular check-up of baclofen pump may decrease the incidence of intrathecal baclofen withdrawal syndrome. Oral baclofen replacement may not be an effective method to treat or prevent intrathecal baclofen withdrawal syndrome. Management includes an early recognition of syndrome, proper intensive care management, high-dose benzodiazepines and prompt analysis of intrathecal pump with reinstitution of baclofen.

Treatment of spasticity in a spinal cord-injured patient with intrathecal morphine due to intrathecal baclofen tolerance--a case report and review of literature

STUDY DESIGN

Case report.

OBJECTIVE

To report treatment of spasticity in a spinal cord-injured person with intrathecal morphine after the person developed tolerance to intrathecal baclofen.

METHOD

Spasticity in a 36-year-old man with T6 complete paraplegia was treated with increasing doses of intrathecal baclofen. When he developed tolerance to intrathecal baclofen, he was given continuous infusion of morphine intrathecally.

SETTING

Regional Spinal Injuries Centre, UK.

RESULTS

Spasticity was adequately controlled by intrathecal morphine.

CONCLUSION

In spinal cord-injured patients with severe spasticity, who become tolerant to intrathecal baclofen, treatment with intrathecal morphine may be useful.

Microfracture of a baclofen pump catheter with intermittent under- and overdose

An 8-year-old boy with an implanted intrathecal baclofen pump presented with intermittent signs of baclofen under- and overdose. Pump interrogation, pump volumes, plain X-rays, catheter contrast fluoroscopy and CT of the intrathecal catheter tip were unremarkable. A microfracture of the extradural catheter was only seen at a magnification of x20 and confirmed by scanning electron microscopy. Symptoms resolved following replacement. Microfracture of the intrathecal catheter of baclofen pump systems may present puzzling symptomatology and be difficult to diagnose by conventional means.

Intrathecal baclofen withdrawal mimicking sepsis

Baclofen (Lioresal) is a drug of choice to treat spasticity and is increasingly being administered intrathecally via an implantable pump in cases refractory to oral therapy. Emergency physicians will likely treat patients with baclofen withdrawal or overdose as this treatment becomes more widespread. The syndrome of baclofen withdrawal presents with altered mental status, fever, tachycardia, hypertension or hypotension, seizures, and rebound spasticity, and may be fatal if not treated appropriately. Baclofen withdrawal may mimic other diseases including sepsis, meningitis, autonomic dysreflexia, malignant hyperthermia, or neuroleptic malignant syndrome. Treatment consists of supportive care, reinstitution of baclofen, benzodiazepines, and diagnosis and eventual repair of intrathecal pump and catheter malfunction.

Baclofen withdrawal following removal of an intrathecal baclofen pump despite oral baclofen replacement

Intrathecal baclofen is used as a muscle relaxant and antispasmodic in cases of spasticity resulting from central nervous system trauma. The baclofen withdrawal syndrome may include hyperthermia, tachycardia, hypertension, seizures, altered mental status, and psychomotor agitation. We report a case in which the removal of a baclofen pump lead tothe development of severe withdrawal symptoms despite oral baclofen replacement therapy. In order to avoid the development of withdrawal, adequate doses of GABA agonist agents should be administered immediately prior to, and following, baclofen pump removal.

The role of surgical placement and pump orientation in intrathecal pump system failure: a technical report

Intrathecal pump catheter complications are the most common cause of failure in drug delivery. A previous report has documented that intra-abdominal positioning of the intrathecal pump may predispose the pump-catheter neck to premature catheter breakdown and leakage. Based on this report, we reviewed over 100 intrathecal pump cases to determine the frequency of malpositioning and its role in the pathogenesis of catheter failure. We found three specific cases where a 'fulcrum effect' occurred due to intra-abdominal positioning of the pump predisposing the catheter to breakdown. This study demonstrates that intra-abdominal placement of the pump can predispose the catheter to failure/breakdown and that surgeons should attempt to place the pump catheter neck in a superiomedial position, distant from any bony prominences, to prevent the 'fulcrum effect' on the pump-catheter neck junction and reducing the likelihood of either internal or external compressive forces.

Intrathecal baclofen therapy in children with cerebral palsy: efficacy and complications

OBJECTIVES

To describe the efficacy of intrathecal baclofen (ITB) therapy in the management of spasticity in young children with cerebral palsy (CP) and to identify risk factors for complications.

DESIGN

Consecutive case series of 25 implanted ITB delivery systems during a 48-month period.

SETTING

Pediatric specialty hospital and outpatient department.

PARTICIPANTS

Twenty-three children (age range, 4.5-17.4y) with CP (spastic diplegia in 22%; spastic quadriplegia in 61%; mixed-type diplegia in 4%; mixed-type quadriplegia in 13%).

INTERVENTION

Intrathecal baclofen therapy in children with cerebral palsy.

MAIN OUTCOME MEASURES

Ashworth Scale scores before treatment and at 6 and 12 months after ITB therapy; frequency and nature of complications; and relation between patient characteristics and outcomes.

RESULTS

Average Ashworth scores +/- standard deviation decreased from 3.26+/-.73 to 2.34+/-.83 (P<or=.01) in the lower extremities and from 2.69+/-.79 to 2.00+/-.55 (P<or=.05) in the upper extremities 6 months after ITB therapy and remained comparably decreased at 12 months. Explantation was required in 44% (11/25), with wound complications as the leading cause in 73% (8/11). Complications were associated with the diagnosis of mixed-type CP, as compared with pure spastic types (P<or=.01). Trends suggest that children of smaller size and younger age, as well as those with gastrostomy tubes and nonambulatory status, were more likely to encounter complications necessitating explantation.

CONCLUSION

ITB therapy effectively reduced spasticity in children with CP. However, complications necessitating explantation can occur. Further research is needed to identify criteria describing the ideal pediatric candidate for ITB.

Abrupt withdrawal from intrathecal baclofen: recognition and management of a potentially life-threatening syndrome

OBJECTIVE

To suggest guidelines for the prevention, recognition, and management of a life-threatening syndrome (high fever, altered mental status, profound muscular rigidity that sometimes progressed to fatal rhabdomyolysis) in patients who experience the abrupt withdrawal of intrathecal baclofen (ITB) therapy.

DESIGN

Retrospective literature and safety-file review.

SETTING

Expert panel drawn from physiatry, neurology, and neurosurgery.

PARTICIPANTS

Experienced users of ITB therapy in the pediatric and adult populations in the United States.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

We reviewed literature reports, MedWatch reports to the US Food and Drug Administration, and our own experiences. We critically analyzed patient management and drug therapy in the context of the pharmacology of baclofen and other antispastic agents.

RESULTS

An abrupt reduction in gamma-aminobutyric acid(B) (GABA) agonist activity in the central nervous system can cause the ITB withdrawal syndrome, which is clinically and pathophysiologically distinct from autonomic dysreflexia, malignant hyperthermia, and neuroleptic-malignant syndrome. ITB withdrawal evolves over 1 to 3 days, but may become fulminant if not recognized and treated early. The syndrome can be interrupted by the restoration of ITB therapy. However, supportive measures and high-dose benzodiazepine infusion may be life saving in the interval before ITB therapy is resumed. Dantrolene infusion may relieve muscle rigidity but does not reverse the other manifestations of GABAergic agonist withdrawal.

CONCLUSIONS

Most episodes of severe ITB withdrawal were preventable. Patients at risk can be identified and educated prospectively and given medication for emergency use. Treatment with GABAergic agonist drugs may prevent potentially fatal sequelae.

Recurrent intrathecal baclofen pump catheter leakage: A surgical observation with recommendations

Intrathecal baclofen pump catheter complications are the most common cause for failure in drug delivery. A 4-year-old boy presented with repeated signs of baclofen tolerance despite progressive increases in dosing. External computerized interrogation of the pump and radiograph evaluation of the pump-catheter-intrathecal sac system were normal. Subsequently, he was taken to the emergency room for baclofen overdosage and brought to the operating room for exploration of the implant. Intraoperative assessment of the pump catheter found a cut on the catheter neck that was visible only when the catheter neck was flexed. The catheter was replaced without complications. Two months later, the patient returned with similar symptoms. Repeat computerized and radiographic assessment of the pump were normal. Intraoperative assessment showed a cut within the same portion of the catheter as previously discovered. The catheter cut was in the least flexible portion, the pump-catheter neck, which was found to be overlying the iliac crest in both surgeries. The authors hypothesize that the repetitive compressive forces of the catheter overlying the iliac crest led to catheter breakdown. Surgical placement of the pump-catheter neck should be superio-medial to reduce the likelihood of either internal or external compressive forces.

Selective posterior rhizotomy and intrathecal baclofen for the treatment of spasticity

Spasticity occurs in children and adults due to a wide range of conditions, including cerebral palsy, head and spinal cord trauma, cerebrovascular accidents and multiple sclerosis. Multiple treatment options have been described, including medical and surgical treatments. Medical treatments include intramuscular botulinum A toxin, oral baclofen and supportive bracing. Surgical approaches include selective posterior rhizotomy, intrathecal baclofen and orthopedic procedures to address deformities. Many reports have been published on these different treatment options, but rarely has a comparison been made between them. Therefore, this review is aimed at comparing selective posterior rhizotomy and intrathecal baclofen injection for spasticity due to cerebral palsy, especially in children.

Radioisotopic control for baclofen pump catheter failure

STUDY DESIGN

Case report of Baclofen pump catheter failure investigated by radioisotope injection.

OBJECTIVES

To report a safe and reliable method for evaluating catheter dysfunction.

SETTING

France.

METHODS

Single case report of failure of Baclofen pump investigated by radioisotope injection.

RESULTS

The injection demonstrated the block in the catheter. The catheter failure was not visualised by plain X-ray nor by filling the pump with radio-opaque solution.

CONCLUSION

Catheter failure is a common cause of intrathecal drug delivery problems and may be difficult to diagnose. When catheter disconnection, kink, or dislodgement is not visible on X-ray, radioisotopic control is a safe and reliable method for assessment.

Neuroleptic malignant-like syndrome after abrupt withdrawal of baclofen

We present the case of a 36-year-old man who presented with a clinically neuroleptic malignant-like syndrome involving disorientation, signs of autonomic dysfunction, rigidity and raised total creatine kinase level, but in the absence of any neuroleptic medication. He had, however, abruptly stopped taking his long-term baclofen in the days prior to presentation. He improved markedly after the reintroduction of baclofen, and we postulate that his clinical syndrome resulted from the sudden withdrawal of this drug. We concur with the concept that neuroleptic malignant syndrome represents a spectrum of disorders, and add it to the list of possible sequelae after abrupt withdrawal of baclofen.

Succinylcholine-induced hyperkalemia and rhabdomyolysis in a patient with necrotizing pancreatitis

IMPLICATIONS

Commonly used muscle relaxants may have serious side effects when used in critically ill patients. This case report relates some of these side effects and reviews the mechanisms by which they are thought to occur.