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

Selective percutaneous myofascial lengthening of the lower extremities in children with spastic cerebral palsy

Children with spastic cerebral palsy commonly acquire lower extremity musculoskeletal deformities that at some point may need surgical correction. The authors present 58 children with spastic cerebral palsy who underwent selective percutaneous myofascial lengthening of the hip adductor group and the medial or the lateral hamstrings. All the patients were spastic diplegic, hemiplegic, or quadriplegic. The indications for surgery were a primary contracture that interfered with the patients' walking or sitting ability or joint subluxation. Gross motor ability and gross motor function of the children were evaluated using the gross motor function classification system (GMFCS) and the gross motor function measure (GMFM), respectively. The mean time of the surgical procedure was 14 minutes (range, 1 to 27 minutes). All patients were discharged from the hospital setting the same day after the operation. There were no infections, overlengthening, nerve palsies, or vascular complications. Three patients required repeat procedures for relapsed hamstring and adductor contractures at 8, 14, and 16 months postoperatively. At 2 years after the initial operation, all the children improved on their previous functional level; 34 children improved by one GMFCS level, and 5 children improved by two GMFCS levels. The overall improvement in mean GMFM scores was from 71.19 to 83.19.

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.

Prevention of intrathecal baclofen withdrawal syndrome: successful use of a temporary intrathecal catheter

Abrupt cessation of intrathecal baclofen (ITB) administration can cause a life-threatening withdrawal syndrome that requires prompt diagnosis and urgent treatment. The current therapy for this condition is administration of propofol, benzodiazepines, paralytics and supportive care. This study reports a 53-year-old patient with paraplegia with an ITB infusion who presented with an infected pump site. The pump and the catheter were surgically removed and replaced with a temporary externalized intrathecal catheter. The ITB infusion was tapered and simultaneously substituted with progressively higher doses of oral antispasmotics. With this strategy, we were able to avoid life-threatening complications.

Potential clinical impact of compounded versus noncompounded intrathecal baclofen

OBJECTIVE

To assess the differences between commercial and pharmacy-compounded preparations of baclofen for intrathecal administration.

DESIGN

Random sample.

SETTING

Pharmacies in the United States advertising compounded intrathecal baclofen preparation.

PARTICIPANTS

Not applicable.

INTERVENTIONS

Intrathecal baclofen (ITB) samples were collected from 1 Food and Drug Administration-approved commercial source and 6 compounding pharmacies. An independent analysis of drug concentration and density was conducted. Information regarding ordering process, manufacturing, packaging, storage, and expiration was collected.

MAIN OUTCOME MEASURE

Comparison of concentration and density variations.

RESULTS

Twenty-nine ITB samples in concentrations of 2000, 3000, 4000, 5000, and 6000 microg/mL were analyzed. Over 40% of compounded samples were more than 5% above or below labeled concentration. Twenty-two percent of compounded samples were more than 10% above or below labeled concentration. The only samples with no concentration deviation and consistent drug density were the commercially available, noncompounded products.

CONCLUSIONS

Compounding pharmacies have variable practices in the provision of ITB. A high incidence of concentration inaccuracy existed. The use of compounded ITB may result in unintended dose alterations. Variable clinical efficacy, or life-threatening overdose or withdrawal may occur in patients who are sensitive to slight dose fluctuations. Given the variability of these compounded ITB samples, informed consent to use these products and understanding of potential side effects should be reviewed with patients.

Surgical management of spasticity in persons with cerebral palsy

Cerebral palsy is a disorder that primarily affects the neurologic system but secondarily affects the musculoskeletal system through the effects of spasticity, dystonia, and other movement disorders. The treatment of cerebral palsy requires a multidisciplinary approach with treatment aimed at modulating the movement disorder through oral medication, injectable drugs (phenol, botulinum toxin), and physical and occupational therapy. Treatment of the neurologic effects of the central movement disorders include selective dorsal rhizotomy, intrathecal baclofen pump placement, and potentially deep brain stimulation. Although any effect on tone is temporary, orthopedic surgery has an important role in the treatment of the musculoskeletal deformities and contractures present in the child with cerebral palsy. Orthopedic surgery improves function by lengthening the musculotendinous structures, transferring tendons, performing osteotomies to reduce dislocated joints, and normalizing rotation and fusion of selected joints to improve stability. Neurosurgical techniques are not as widely used, but may reduce spasticity in select individuals. The combined approach of managing tone and normalizing the biomechanics of the spine and upper and lower extremities through orthopedic surgery and neurosurgery and subsequent rehabilitation is the cornerstone of treatment of the child and adult with cerebral palsy.

Intrathecal baclofen use in adults with cerebral palsy

Intrathecal baclofen (ITB) is an effective treatment for both spasticity and dystonia in people with cerebral palsy (CP). Its use is becoming increasingly common. ITB is typically associated with fewer side effects than the oral form of the product, but there are risks related to the hardware needed for intrathecal delivery. Much of what has been reported in the literature about ITB is based on experience with children or groups of children and adults; few reports exclusively address its use in adults with CP. These reports indicate that muscle tone is consistently reduced, but there is some variability in functional outcomes. Few well-controlled studies have been done. Controversies remain concerning ITB, including whether a trial is needed before pump implantation, proper catheter tip placement, and programming options, as well as whether it contributes to the development or progression of scoliosis. These and other unanswered questions should be addressed in a systematic way.

Normalization of central cord syndrome spinal cord injury urodynamics after intrathecal baclofen therapy: a case report

Objective. To report a case of improved urodynamics in a central cord syndrome spinal cord injury after intrathecal baclofen therapy. Methods. A 47-year-old man fell resulting in C4-C5 disc herniation with ventral spinal cord compression and cord edema. Results. He underwent an anterior cervical discectomy and fusion. Postoperatively, his examination revealed a C4 ASIA D injury in a central cord syndrome pattern. Cystometrogram (CMG) revealed a hyperactive detrusor with sphincter dyssynergia managed with intermittent self-catheterization. One and a half years later, he was impaired by severe lower limb spasticity, despite oral medications and botulinum toxin injections. After intrathecal pump therapy, CMG revealed relatively normal detrusor and minimal sphincter tone. He volitionally voids with urgency but improved continence, which was maintained in one-year follow-up. Conclusion. Although the main indication for intrathecal baclofen therapy is spasticity, improved urodynamics can be an additional benefit in central cord syndrome spinal cord injury.

[Neuromodulation of spasticity in children by intrathecal baclofen]

INTRODUCTION

Treatment with intrathecal baclofen (ITB) is an important part of the complex therapy of patients with cerebral spasticity aiming to improve the motoric functions and to reduce pain intensity.

MATERIAL AND METHODS

ITB was started in the Orthopaedic Hospital in Speising in 1999. From 1999 to 2006 a total of 15 children aged 3 to 16 years old were selected for this special treatment.

RESULTS

The average degree of spasticity according to Ashworth (scale 1-5) could be reduced by ITB from 4.38 to 3.0, the time spent sitting could be increased from 3.3 to 5.8h per day and the pain intensity (VAS 1-10) could be reduced from 4.2 to 0.6. The time necessary for nursing treatment was shortened from 7.5 to 3.4 (VAS 1-10). Also improved was the emotional situation, the ability to swallow, the posture of the head and the concentration ability.

CONCLUSION

ITB provides neuromodulation even in pediatric patients with complex neuromotoric spasticity.

Neuroleptic malignant syndrome from central nervous system insult: 4 cases and a novel treatment strategy. Clinical article

Neuroleptic malignant syndrome (NMS) is a potentially life-threatening entity characterized by hyperthermia, autonomic deregulation, decreased mental status, increased muscle tone, and, frequently, by renal failure due to rhabdomyolysis. Classically, it follows administration of antipsychotic medication. The authors report on 4 patients (2 children and 2 adults) in whom NMS was diagnosed after a CNS insult. No patient was receiving antipsychotic medication. The patients' hospital and clinic charts, radiographic data, and follow-up telephone conversations were reviewed retrospectively. All 4 patients met diagnostic criteria for NMS. Three patients presented with shunt failure, and 1 patient had undergone a functional hemispherectomy 2 days earlier. One patient with shunt failure received the diagnosis retrospectively. An endoscopic third ventriculostomy alleviated his shunt failure and he remains free of NMS. The other 2 patients underwent treatment for shunt failure, but NMS remained. These 2 patients and the one who had undergone hemispherectomy underwent a trial of intrathecal baclofen, and the NMS resolved. Subsequently, an intrathecal baclofen infusion device was placed in all 3 patients, and the NMS resolved. The 2 patients in shunt failure had a lumbar intrathecal baclofen infusion device. The patient who had undergone hemispherectomy had an intracranial baclofen catheter. Neuroleptic malignant syndrome is a rare, life-threatening disorder that can occur without the administration of neuroleptic medications. Alleviation of any CNS insult is the first order of treatment. Some patients with persistent symptoms of NMS may benefit from intrathecal delivery of baclofen.

Pharmacological management of Dysautonomia following traumatic brain injury

PRIMARY OBJECTIVE

To document and critically evaluate the likely effectiveness of pharmacological treatments used in a sample of patients with Dysautonomia and to link these findings to previously published literature.

RESEARCH DESIGN

Retrospective case control chart review.

METHODS AND PROCEDURES

Data were collected on age, sex and GCS matched subjects with and without Dysautonomia (35 cases and 35 controls). Data included demographic and injury details, physiological parameters, medication usage, clinical progress and rehabilitation outcome. Descriptive analyses were undertaken to characterize the timing and frequency of CNS active medications.

MAIN OUTCOMES AND RESULTS

Dysautonomic patients were significantly more likely to receive neurologically active medications. A wide variety of drugs were utilised with the most frequent being morphine/midazolam and chlorpromazine. Cessation of morphine/midazolam produced significant increases in heart rate and respiratory rate but not temperature. Chlorpromazine may have modified respiratory rate responses, but not temperature or heart rate.

CONCLUSIONS

The features of Dysautonomia are similar to a number of conditions treated as medical emergencies. Despite this, no definitive treatment paradigm exists. The best available evidence is for morphine (especially intravenously), benzodiazepines, propanolol, bromocriptine and possibly intrathecal baclofen. Barriers to improving management include the lack of a standardized nomenclature, formal definition or accepted diagnostic test. Future research needs to be conducted to improve understanding of Dysautonomia with a view to minimizing disability.

Management of spasticity in children with cerebral palsy

Spasticity and other forms of muscle overactivity caused by cerebral palsy may impair function or ease of care or may cause discomfort or poor body image. The treatment program for a child with spasticity may include allied health therapy, exercise, casting, constraint-induced therapy, oral medications, chemodenervation, intrathecal baclofen, selective dorsal rhizotomy, and orthopedic surgery. Techniques may be combined for greater efficacy and better tailoring to the needs of the child. This article provides an overview of each approach, with a review of significant research findings in support of each.

Intrathecal baclofen for autonomic instability due to spinal cord injury

Autonomic dysreflexia may occur following spinal cord injury above mid-thoracic level, commonly developing in the early posttraumatic period. Cardiovascular dysregulation is the most prominent feature, characterized by paroxysmal high blood pressure attacks, which are precipitated by distension of urinary bladder or bowels, skin wounds, or increased spastic muscle tone. Severe drops in blood pressure may occur in orthostatic conditions. Baclofen is effective for treating spasticity. While orally administered baclofen often fails to alleviate severe spasticity adequately, intrathecal baclofen (ITB) is more effective and thus is being used increasingly. A 61-year-old male sustained a cervical spinal cord injury, subsequently developing severe spastic tetraparesis, predominantly in the legs. Some 30 years later he experienced marked spasms of the muscles of the abdominal wall, leading to extreme fluctuations of blood pressure. After positive evaluation with ITB the patient underwent implantation of a pump-catheter-system for continuous ITB application. Abdominal wall spasms ceased entirely with a daily dose of 190 microg ITB, accompanied by a sustained normotensive blood pressure profile. However, spasms reoccurred after inadvertent reduction of ITB flow when increasing the pump's ITB concentration but subsided again when the optimal antispastic dose was reestablished. Baclofen per se has the potential of lowering blood pressure. In this patient, however, ITB treatment enabled permanent stabilization of insidious blood pressure fluctuations. It would appear that suppression of abdominal spasms prevented the triggering of dysautonomic crises. This case demonstrates that ITB administration may help to stabilize autonomic dysreflexia and orthostatic hypotension in patients with spinal cord lesions.

Intrathecal administration of GABA agonists in the vegetative state

Gamma aminobutyric acid (GABA) is an inhibitor neurotransmitter that plays many important roles in the central nervous system. Because the half-life time of GABA is very short in vivo, GABA itself is not used for clinical practice. An analogue of GABA, baclofen, is an agonist of GABA-B receptor, and has very strong antispastic effect by acting to the posterior horn of the spinal cord. However, baclofen poorly crosses through the blood brain barrier, and the antispastic effect is modest when administered orally. Therefore, direct continuous infusion of small doses of baclofen into the cerebrospinal fluid (intrathecal baclofen therapy, ITB) has become an established treatment for control of otherwise intractable severe spasticity. Spasticity is clinically defined as hypertonic state of the muscles with increased tendon reflexes, muscles spasm, spasm pain, abnormal posture, and limitation of involuntary movements. Spasticity is a common symptom after damage mainly to the pyramidal tract system in the brain or the spinal cord. Such damage is caused by traumatic brain injury, stroke, spinal cord injury, multiple sclerosis, and so on. Patients in persistent vegetative state (PVS) usually have diffuse and widespread damage to the brain, spasticity is generally seen in such patients. Control of spasticity may become important in the management of PVS patients in terms of nursing care, pain relief, and hygiene, and ITB may be indicated. Among PVS patients who had ITB to control spasticity, sporadic cases of dramatic recovery from PVS after ITB have been reported worldwide. The mechanism of such recovery of consciousness is poorly understood, and it may simply be a coincidence. On the other hand, electrical spinal cord stimulation (SCS) has been tried for many years in many patients in PVS, and some positive effects on recovery of consciousness have been reported. SCS is usually indicated for control of neuropathic pain, but it has also antispastic effect. The mechanism of SCS on pain is known to be mediated through the spinal GABA neuronal system. Thus, ITB and SCS have a common background, spinal GABA neuronal mechanism. The effect of GABA agonists on recovery of consciousness is not yet established, but review of such case studies becomes a clue to solve problems in PVS, and there may be hidden serendipity.

Intrathecal baclofen withdrawal resembling serotonin syndrome in an adolescent boy with cerebral palsy

Intrathecal baclofen (ITB) is increasingly being used to reduce spasticity among children with cerebral palsy, dystonia, and spinal cord injuries. However, complications such as withdrawal, which is a potentially life-threatening condition, can occur. Intrathecal baclofen withdrawal should be differentiated with autonomic dysreflexia, malignant hyperthermia, neuroleptic malignant syndrome, and serotonin syndrome. We report a case of ITB withdrawal secondary to low residual volume in the pump reservoir and resembling serotonin syndrome in an adolescent with cerebral palsy. He presented with agitation, diaphoresis, increasing spasticity, rigidity, jitteriness, hyperreflexia, clonus, tachycardia, hypertension, and rhabdomyolysis. Treatment consisted of emergent refilling of the pump, intravenous diazepam, and oral cyproheptadine. We also emphasize the importance of prompt recognition of ITB withdrawal among high-risk patients.

Intrathecal drug therapy for long-term pain management

PURPOSE

The use, safety, and efficacy of intrathecal medication administration with implantable pumps for cancer and chronic pain management are reviewed.

SUMMARY

Implanted intrathecal drug-delivery systems (IDDSs) are used for long-term management of persistent, severe pain despite a multimodal approach with conventional pain treatment options. Currently, consensus papers published in the literature are used as guidelines for determining patient selection and medication administration, because there is a lack of supporting evidence from randomized, controlled, clinical trials. Pharmacists have a critical role in the safe use of intrathecal medication. Most of the medication concentrations and combinations administered through IDDSs are not commercially available and therefore must be compounded in a pharmacy. Medications commonly administered through IDDSs include opioids, local anesthetics, clonidine, baclofen, and ziconotide. It is important for pharmacists who prepare products for IDDSs to understand the pharmacology, adverse effects, and concentration limitations of each medication in order to prevent adverse events related to postoperative subarachnoid hemorrhage, infection, catheter-tip inflammatory masses, withdrawal, and overdose. Pharmacists play an important role in maintaining quality assurance of intrathecal drug use, including the use of standard procedures for ordering and compounding medications, documentation of patient education, and monitoring of patient outcomes.

CONCLUSION

The use of long-term intrathecal drug delivery for the treatment of intractable pain or intolerable medication adverse effects has expanded to include the treatment of patients with chronic or cancer-related pain. Important considerations for the use of intrathecal drug therapy include the appropriate selection of patients, delivery systems, and medications, as well as potential complications of therapy and quality-assurance measures necessary to ensure patient safety.

Cyproheptadine for pediatric intrathecal baclofen withdrawal: a case report

Intrathecal baclofen withdrawal syndrome is a known complication of intrathecal baclofen pumps. Its origin is postulated as an independent form of a serotonergic syndrome occurring from loss of gamma-aminobutyric acid B receptor-mediated inhibition of serotonin. Prodromal symptoms include pruritus, a return of deep tendon reflexes, and increased spastic hypertonia. Previous reports have documented use of cyproheptadine in treatment of this syndrome in adults with positive results. We present the case of a 14-yr-old child with cerebral palsy who developed pruritus and worsening spastic hypertonia 18 mos after pump implantation. She had been previously treated with 520 microg/day of intrathecal baclofen. Progression of her symptoms was successfully arrested by the administration of both oral and intrathecal baclofen and 6 mg of oral cyproheptadine every 6 hrs for 1 day. We postulate that cyproheptadine should be considered a valuable adjuvant therapy for treatment of suspected intrathecal baclofen withdrawal syndrome.

[Continuous intrathecal administration of medication. Special features in anaesthesiology and intensive care]

In anaesthesiological and intensive care practice patients are increasingly being treated with implanted medication pumps. Basic knowledge on the special aspects of this form of therapy is therefore important. During the preanasthesiology visit, information on the pump, the intrathecal catheter, type and dosage of the medication as well as the next scheduled refilling must be collected and documented. Needle punctures near the pump and the catheter must be avoided. During intensive care treatment any possible interaction and overdosing or underdosing of the intrathecally administered medication must be considered. Information on the schedule and punctual organisation of refilling are important to avoid complications.

The excitatory:inhibitory ratio model (EIR model): An integrative explanation of acute autonomic overactivity syndromes

Numerous medical conditions present with acute and severe autonomic and muscular overactivity. These syndromes include Neuroleptic Malignant Syndrome, Serotonin Syndrome, Dysautonomia (or paroxysmal sympathetic storms) following acquired brain injury, Autonomic Dysreflexia, Parkinsonian-Hyperpyrexia Syndrome, Malignant Catatonia, intrathecal baclofen withdrawal, Malignant Hyperthermia, Stiff Man Syndrome and Irukandji Syndrome. In their worst forms, each of these syndromes are relatively rare, are treated by different medical specialties and show widely varying pathophysiology. Most are considered to be medical emergencies and share significant mortality rates. Previous authors have noted similarities between some of these conditions, prompting the suggestion that a single common mechanism may underlie their clinical presentation. However, the development of such an integrative model has not occurred. This paper presents a short review of the clinical syndromes, grouped by the location of pathology and mechanism of action. From this background, an integrative framework termed the excitatory:inhibitory ratio (EIR) model is presented. The EIR model consists of two inter-related networks operating at spinal and brainstem levels. The model is evaluated against pre-clinical scientific research, known pathways, each disorder's pathophysiology (where this is known) and variable severity, and used to explain the reasons behind the efficacy of current treatment regimes. Circumstantial evidence for an expanded aetiology for Malignant Hyperthermia is provided and generic treatment strategies for a number of other conditions are suggested. Finally, minor modifications to this model provide a basis to begin to explain less severe, regional "overlap" syndromes.

Prolonged, severe intrathecal baclofen withdrawal syndrome: a case report

Intrathecal baclofen (ITB) withdrawal is a well-recognized complication when drug delivery is disrupted for any reason. ITB withdrawal varies widely in its severity and poses the very real possibility of death if not promptly managed. Cases of withdrawal lasting greater than 1 or 2 weeks, however, are sparse. We report the case of an 11-year-old girl with spastic quadriplegic cerebral palsy who developed an infected pump and subsequent meningitis, prompting the removal of her pump and catheter. She subsequently developed a severe, prolonged baclofen withdrawal syndrome marked by increased spasticity, agitation, hypertension, and tachycardia that lasted nearly 2 months, requiring intensive care and continuous intravenous sedation with benzodiazepines and opiates. Her pump was eventually replaced on hospital day 56 and within 24 hours her symptoms dramatically improved. She was eventually weaned off sedating medications and returned to baseline functional status. Typical management of baclofen withdrawal is reviewed. To date, the literature has not discussed the potential role for opiates in managing baclofen withdrawal, yet a growing body of literature is examining the interplay between opiates and gamma-aminobutyric acid B pathways. A potential role for opiates in managing severe baclofen withdrawal is proposed.

Infusion of intrathecal baclofen for acute withdrawal

✓ Acute baclofen withdrawal syndrome is a life-threatening situation that demands early recognition and urgent treatment. The current therapy of choice for this syndrome is administration of intravenous benzodiazepines, propofol, and chemical paralytic drugs until the intrathecal system can be restored. The authors present a novel technique for administering baclofen intrathecally using a lumbar drain and a standard patient-controlled analgesia pump (in continuous infusion mode). In one case, this method was used to wean the patient from high-dose intrathecal baclofen treatment. In a second case, this method was used as a temporizing measure until the indwelling pump system could be repaired. In both cases, the patients recovered to their neurological baseline level, and lasting consequences of serious withdrawal were avoided.

Intrathecal baclofen in the treatment of spasticity, dystonia and vegetative disorders

Baclofen (beta-p-chlorophenyl-GABA) binds to a number of spinal and cerebral sites and depresses the excitability of motor neurons. Intrathecal administration induces much higher CSF concentrations compared to the limited passage through the blood-brain barrier after oral administration. The development of reliable implanted pumps allows long-term intrathecal baclofen treatment (ITB). Baclofen is mainly an antispastic drug and the main indication of ITB is generalized lower limb spasticity in spinal cord injury and multiple sclerosis. The side-effects are due to either drug over-dose or withdrawal and to malfunctions of the implanted device (disconnections of the catheter, infections, etc.). Large numbers of patients have been treated over the past twenty years. More recently, baclofen has been used in the treatment of spasticity of cerebral origin, and in the treatment of other motor disorders, mainly dystonia. The results in cerebral palsy are promising and ITB's role will probably grow in the management of the movement disorders of these children. Further studies are required on the exact site of action, on the possible association with other drugs, especially clonidine and on the development of sustained release formulations.

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.

Interaction of ventriculoperitoneal shunt and baclofen pump

OBJECTIVE

The authors present three cases of children with shunted hydrocephalus and intrathecal delivery of baclofen via an implanted pump. Each case illustrates a potential interaction of these devices.

MATERIALS AND METHODS

A review of the pertinent charts, operative notes, and discharge summaries was performed, along with examination of the pertinent literature.

CONCLUSION

The first case illustrates that a change in the pharmacology or effect of intrathecal baclofen may be caused by a failure of a shunt affecting cerebrospinal fluid clearance. The second case illustrates that patients can have ventricular changes with any procedure that accesses the thecal space, even with a functioning shunt. The third case illustrates that ensuring that a patient's shunt is functional before implantation of a baclofen pump is imperative. As the potential pool of patients with both shunted hydrocephalus and need for intrathecal baclofen grows, clinicians should be aware of potential serious interactions.

Intrathecal baclofen in current neuromodulatory practice: established indications and emerging applications

Intrathecal baclofen (ITB) has evolved into a standard treatment for severe spasticity of both spinal and cerebral origin. The accumulated promising data from reported series of patients receiving ITB therapy together with the fact that spastic hypertonia commonly coexists with other neurological disorders have constituted a solid basis for offering this kind of treatment to patients suffering from other movement disorders. These include motor disorders such as dystonia, amyotrophic lateral sclerosis, status dystonicus, Hallervorden-Spatz disease, Freidreich's ataxia, "stiff-man" syndrome, but also vegetative states after revere brain trauma, anoxic encephalopathy or other pathology and more recently, various chronic pain syndromes. In this article, on the basis of the established applications of ITB therapy, we review the important emerging indications of this rewarding neuromodulation method and attempt to identify its future potential beneficial role in other chronic and otherwise refractory neurological disorders.

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.

Intrathecal baclofen in the management of post-stroke hypertonia: current applications and future directions

This chapter will review the application of intrathecal baclofen (ITB) in the management of post-stroke hypertonia, a major complication that results in deformity and discomfort, and limits mobility and performance of activities of daily living (ADL). Initially, ITB was considered only in conditions characterized by severe multi-limb spastic hypertonia in non-ambulatory individuals. Lately, ITB is used in persons with stroke who can ambulate, with the intent of further improving walking ability. Early clinical experience and evidence suggest that when used in the appropriate patient, ITB is efficacious and safe in managing post-stroke hypertonia in individuals of various functional levels. This chapter will also review clinical situations that are common in the stroke population, which may influence treatment decision choices. There are still ample opportunities to conduct research on this treatment modality, especially in the areas of patient selection and outcomes in the stroke population.

Intrathecal baclofen in the treatment of spasticity

Spasticity is a disorder of the sensorimotor system resulting in velocity-dependent increased muscle tone and tendon reflexes. Intrathecal baclofen is currently the most effective means of treating diffuse abnormal spasticity of both cerebral and spinal origin in the adult and pediatric patient. Careful patient assessment, selection and continued therapies are essential to a successful intrathecal baclofen management program. Once a patient receives a baclofen pump, close monitoring is needed for dose adjustment and pump problems. Baclofen overdose and withdrawal by either system failure or human error can cause significant side effects and be life threatening. Excellent understanding of the baclofen delivery system, programming and dose effects are needed to evaluate any patient complaints. Future uses of intrathecal pump therapy includes use of other intrathecal drugs besides baclofen (or in combination with baclofen) and the effects of placing the catheter tip at various spinal levels. At the University of Minnesota, Sister Kenny Institute and Gillette Children's Specialty Healthcare our experience has shown excellent results with this form of therapy over the last 12-16 years.

Placebo controlled utility and feasibility study of the H-reflex and flexor reflex in spastic children treated with intrathecal baclofen

OBJECTIVE

To evaluate feasibility and utility of the soleus H-reflex and tibialis anterior flexor reflex (FR) in identifying spinal cord neuronal response to intrathecal baclofen (ITB) in children with severe spastic cerebral palsy.

METHODS

During a randomized, double-blind, placebo-controlled dose-escalation test treatment, maximum H amplitude/maximum M amplitude (H/M ratio) and FR parameters were bilaterally recorded at baseline and 2-3 h after intrathecal bolus administration of placebo and increasing doses of baclofen until both an improvement in the individual treatment goal(s) and a one-point reduction on the Ashworth scale were observed.

RESULTS

Electrophysiological data of 14 children were studied. The H-reflex was feasible in 13 children, the FR threshold area in 9 and the FR, elicited with supramaximal stimulation, in only one child. After ITB, the H/M ratio significantly decreased (left: 0.67+/-0.47 to 0.15+/-0.18, P=0.005; right: 0.55+/-0.32 to 0.14+/-0.19, P=0.002) without placebo effect. FR threshold area after ITB, only decreased significantly in children not taking oral baclofen (left: 146+/-53 to 41+/-54 mV ms, P=0.000; right: 156+/-80 to 66+/-48 mV ms, P=0.002).

CONCLUSIONS

This is the first randomized, double-blind, placebo-controlled dose-escalation study in spastic children demonstrating the soleus H-reflex to be a feasible and objective measure to quantify the decreasing motoneuron excitability in response to ITB bolus administration. Only in children not taking oral baclofen, FR threshold area can also be used as an objective outcome measure, yet feasibility is limited.

SIGNIFICANCE

We suggest introducing the H-reflex as the electrophysiological gold standard for the evaluation of the effect of ITB in spastic children.

Intrathecal analgesic drug therapy

Intrathecal analgesic infusion therapy through an implantable pump system is a sophisticated medical therapy for those who suffer from chronic, severe pain who are unresponsive to traditional medical therapy. This article describes the patient selection and monitoring process and reviews available intrathecal medications and combinations.

Cerebral palsy: comprehensive review and update

Cerebral palsy (CP) is a common pediatric disorder occurring in about 2 to 2.5 per 1000 live births. It is a chronic motor disorder resulting from a non-progressive (static) insult to the developing brain. CP is the clinical presentation of a wide variety of cerebral cortical or sub-cortical insults occurring during the first year of life. The commonest cause of CP remains unknown in 50% of the cases; prematurity remains the commonest risk factor. Children with CP suffer from multiple problems and potential disabilities such as mental retardation, epilepsy, feeding difficulties, and ophthalmologic and hearing impairments. Screening for these conditions should be part of the initial assessment. The child with CP is best cared for with an individualized treatment plan that provides a combination of interventions. This requires the provision of a number of family-centered services that make a difference in the lives of these children and their families. Management of spasticity can be challenging with a wide variety of possible therapeutic interventions. The treatment must be goal oriented, such as to assist with mobility, reduce or prevent contractures, improve positioning and hygiene, and provide comfort. Each member of the child's multidisciplinary team, including the child and both parents, should participate in the serial evaluations and treatment planning.

Delirium Associated With Baclofen Withdrawal: A Review of Common Presentations and Management Strategies

The authors reviewed 23 published cases of psychiatric symptoms in association with baclofen withdrawal. Delirium, and not other functional psychiatric conditions, arose secondarily from abrupt baclofen cessation. Vulnerability to baclofen-withdrawal delirium appeared to be greater in individuals who received chronic baclofen therapy. Baclofen-withdrawal delirium can be difficult to distinguish from delirium of other etiologies, and unrecognized and inadequately treated baclofen-withdrawal delirium is associated with significant morbidity and mortality. Complete resolution of delirium symptoms was possible with reinstatement of baclofen. The clinical management of patients experiencing baclofen-withdrawal delirium includes supportive interventions to reduce complications of delirium until symptoms resolve.

Rash, fever, and neck pain in the office: is this a neurologic emergency?

Anticonvulsants, neuroleptics, and antispasticity agents are used with increasing frequency in the pediatric population. Each of the drugs discussed in this article has serious but potentially reversible adverse effects. Pediatric primary care providers must be aware of the potential emergencies associated with the use of these neurologic medications to provide prompt and effective treatment.

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.

Severe Seizures During Propofol Induction in a Patient with Syringomyelia Receiving Baclofen

We report the occurrence of recurrent severe generalized seizures during induction of anesthesia with propofol in a patient with syringomyelia receiving baclofen for flexor spasms undergoing neurosurgery. We discuss the possible epileptogenic interaction between baclofen and propofol in our patient.

Pruritus after intrathecal baclofen withdrawal: A retrospective study

OBJECTIVES

To determine the frequency of pruritus after intrathecal baclofen (ITB) withdrawal and to study the pathophysiology of this symptom.

DESIGN

Retrospective cohort study.

SETTING

Rehabilitation department of a general hospital.

PARTICIPANTS

Patients (N=102) implanted with an ITB pump who had been followed up since 1988.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Incidence of pruritus after withdrawal. We studied the relation between pruritus and daily dose, concentration and mode of infusion of baclofen, and cause of the central nervous system lesion inducing spasticity.

RESULTS

Pruritus was observed in 10 of 23 cases of ITB withdrawal. It never occurred during the first 3 months after pump implantation. It seems likely that the segmental spinal action of baclofen is responsible for pruritus. There was no statistically significant difference between patients with ITB deprivation who did and did not experience pruritus in their daily infused dosage or in concentration and mode of infusion. Surprisingly, no pruritus was observed in patients with multiple sclerosis.

CONCLUSIONS

Pruritus is a frequent symptom after ITB withdrawal. Its occurrence is probably subsequent to chronic blocking of the liberation of substance P by baclofen at the spinal level. This symptom is a good clinical predictor of baclofen withdrawal, in contrast to an isolated increase of spasticity that may be due to drug tolerance or irritant factors. Pruritus requires investigation of a possible dysfunction of the infusion system.

Treatment of cervical dystonia and focal hand dystonia by high cervical continuously infused intrathecal baclofen: A report of 2 cases

We describe 2 patients, one with cervical dystonia (CD) combined with focal hand dystonia (writer's cramp) and another with idiopathic CD, who were unresponsive to oral medications and became resistant to botulinum toxin type A and B injections. Both patients were successfully treated with high cervical (C1-3) continuously infused intrathecal baclofen (ITB). Neck range of motion (ROM) was measured by using a 3-dimensional electromagnetic cervical ROM system. Pain, disability, and severity were assessed by using the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS). The patient with CD and writer's cramp did well on a continuous baclofen dose of 186.1 microg/d. Her total TWSTRS score improved significantly, her electromagnetic measurements showed an increased in total neck flexion and extension, and her handwriting improved. Unfortunately, this patient (a heavy smoker) developed small cell carcinoma of the lung and died 9 months after her pump was placed. Total TWSTRS score and electromagnetic measurements also significantly improved after pump implant in the patient with CD. He continues to do well on a periodic bolus dose using a combination of 50 microg of baclofen and 25 microg of hydromorphone (Dilaudid) every 4 hours. Our findings suggest the potential usefulness of this therapy in other patients with focal dystonia. To our knowledge, this is the first reported successful treatment of CD and CD combined with writer's cramp with high cervical continuously infused ITB.

Twenty Years of Pharmacology

During the past 20 years in pharmacology, a number of innovations have appeared that have resulted in significant changes in the drugs available for people with traumatic brain injury. Among the anticonvulsants, antidepressants, and antipsychotics, new drugs have appeared with fewer cognitive side effects. In these classes of drugs, as well as among central nervous system stimulants, once-daily or other sustained-release preparations have been introduced that make it considerably more likely that the patient will take his or her medication, with smaller fluctuations in drug levels as well. New drugs have also resulted in a greater number of medications for the clinician to choose from. The overall effect has been a dramatic change in pharmacology that has benefited people with traumatic brain injury.

Movement disorder emergencies

Movement disorders may present acutely, and failure to recognize and exclude important differential diagnoses can result in significant morbidity or mortality. Unfortunately, much of the literature pertaining to this topic is scattered and not easily accessible. This review aims to address this deficit. Movement disorder emergencies are discussed according to their most likely mode of presentation. Diagnostic considerations and early management principles are reviewed, along with appropriate pathophysiology where relevant.

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.

Intrathecal methods

Although the use of opioids for intrathecal anesthesia was first reported in 1901, it was not until 25 years ago that the first report of selective blockade of pain by spinal opioids was described. Since its beginning, the promise of selective analgesics derived from intraspinal administration has generated much development in the field of pain management. In fact, many anesthesiologists who had previously relegated themselves to the confines of the operating room discovered that their needles and catheters could reach even beyond the inpatient wards, affording patients outside the hospital the opportunity to receive neuraxial drugs. The goal of this article is to report on the current state of spinal analgesic chemotherapy as it is now known.