Death after acute withdrawal of intrathecal baclofen: case report and literature review

Decompression for lumbar spinal stenosis at the intrathecal catheter insertion site during intrathecal baclofen therapy: a case report

BACKGROUND

Intrathecal baclofen therapy can substantially improve symptoms in most patients with severe spasticity due to traumatic spinal cord injury, multiple sclerosis, or cerebral paresis. To the best of our knowledge, decompression surgeries at the intrathecal catheter insertion site in patients with a preexisting intrathecal pump for drug delivery have not been reported.

CASE PRESENTATION

We report the case of a 61-year-old Japanese man with lumbar spinal stenosis who underwent intrathecal baclofen therapy. We performed decompression for lumbar spinal stenosis at the intrathecal catheter insertion site during intrathecal baclofen therapy. The yellow ligament was removed by partial resection of the lamina under a microscope to avoid damage to the intrathecal catheter. The dura mater was distended. No obvious cerebrospinal fluid leakage was observed. Postoperatively, lumbar spinal stenosis symptoms improved, and spasticity remained well controlled with intrathecal baclofen therapy.

CONCLUSIONS

This is the first reported case of lumbar spinal stenosis decompression at an intrathecal catheter insertion site during intrathecal baclofen therapy. Preoperative preparation is necessary, as the intrathecal catheter may be replaced during surgery. We performed surgery without removing or replacing the intrathecal catheter, taking care not to damage the spinal cord by migrating the intrathecal catheter.

Transient alteration of consciousness in spinal cord injury secondary to Baclofen use: a case report

INTRODUCTION

Oral baclofen is commonly used for spasticity management, especially with neurogenic bladder in spinal cord injury (SCI). A less common side effect of baclofen is transient alterations of consciousness, which can easily be confused for altered mental status secondary to orthostatic hypotension in SCI.

CASE PRESENTATION

A 43-year-old man with an acute SCI secondary to an aortic dissection was found to have episodes of confusion after titrating oral baclofen from 5 mg three times per day to 10 mg three times per day at an acute rehabilitation facility. Orthostatic hypotension was initially suspected as the cause of transient alterations of consciousness; however, he was never found to be hypotensive during these episodes. His confusion resolved several days after discontinuation of baclofen.

DISCUSSION

Although, confusion and lightheadedness in SCI are commonly caused by orthostatic hypotension, it is important for physicians to be cognizant of baclofen's side effects, which increase in the setting of acute kidney injury (AKI). If an adverse effect is suspected, baclofen should be tapered while remaining observant for signs of baclofen withdrawal, which can be life-threatening. This case report is a reminder for clinicians to be aware of the uncommon adverse effects of baclofen when initiating therapy in SCI, especially in patients with AKI and neurogenic bladders.

Estimating the National Population of Hospitalized Chronic Baclofen Users: A Cross-Sectional Analysis of a Commercial Claims Database

Background

Baclofen is an effective treatment for spasticity. Abrupt cessation of intrathecal (IT) or oral baclofen risks the development of withdrawal symptoms; however, the magnitude of the problem is unknown.

Objectives

The aims for this study were as follows: (1) using an administrative claims database, estimate the number of patients in the United States on baclofen, and (2) estimate the annual percent hospitalized pediatric and adult populations consequently at risk for interruption of chronic baclofen therapy.

Methods

Using 2011–2014 data representing commercially insured individuals, patients were selected based on insurance coverage; evidence of a baclofen claim; and hospitalization. All patients hospitalized while receiving chronic baclofen were assumed to be at risk for baclofen discontinuation. Yearly counts were determined and then extrapolated to national estimates using census data.

Results

Extrapolating from the claims database, oral or IT baclofen was prescribed annually to 33,061 or 1486 patients ≤ 18 years, and 654,294 or 7084 patients 19–64 years, respectively. The estimated national mean number of at-risk hospitalizations per year for patients aged 19–64 years on chronic oral or IT baclofen was 31,116 and 3774, respectively; patients ≤ 18 years numbered 4691 and 959, respectively. The mean percent of patients hospitalized per year was 42% in those ≤ 18 years receiving IT baclofen compared with 30% in adults, and 3–10% in the populations receiving oral baclofen.

Conclusions

Extrapolation from an administrative claims database was used to estimate the national number and demographics of hospitalized chronic baclofen users. Patients ≤ 18 years receiving IT baclofen were at highest risk of withdrawal due to a high occurrence of hospitalization.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40801-022-00293-8.

In Support of Initial Parenteral Medical Management of Intrathecal Baclofen Withdrawal in Spasticity Patients

Background: Spasticity may present as a wide range of symptoms and conditions. With this protean presentation, a consensus regarding the best course of treatment does not exist. Those patients most severely affected may receive significant benefit from intrathecal baclofen delivery. However, this therapy may itself lead to patient injury in the event of withdrawal. Objective: Withdrawal from intrathecal baclofen may devolve rapidly into a situation in which the patient may incur significant morbidity and even death. A focused, prompt treatment plan would afford the patient the best possible outcome. Methods: The medical literature was reviewed for reports of plans of treatment of baclofen withdrawal and the results obtained. The nature of this problem does not lend itself to a typical study design, depending on case reports and basic pharmacological science application. The paucity of such reports severely limits categorical comparison of patient characteristics and clinical circumstances. Clinical situations, patient characteristics, and therapies were considered and compared. Outcomes of the varied treatments were evaluated for efficacy. Results: Inaccurate diagnoses, delayed correct diagnoses, and the absence of a consistent, treatment plan contributed to widely disparate outcomes. Prompt, correct diagnosis and intensive care unit-based continuous benzodiazepine infusion with titration led to a controlled clinical situation and maximized patient outcomes. Conclusions: Patients going through withdrawal from intrathecal baclofen achieved best outcomes when treated with a continuous infusion and titration of an intravenous benzodiazepine. A well-defined treatment protocol employing this management, reporting serial outcomes, would enable further refinement of the treatment of this clinical problem.

Prepontine placement of an intrathecal baclofen pump catheter for treatment of dystonia

Background:

Cerebral palsy with medically refractory spasticity and dystonia is a condition that often benefits from intrathecal baclofen pump therapy to treat these symptoms. In this case report, an intracranial baclofen catheter was placed in the prepontine space to improve withdrawal symptoms in a patient unable to undergo new lumbar catheter placement due to infection.

Case Description:

A 22-year-old female with past medical history of cerebral palsy presented with baclofen pump failure and was unable to undergo placement of a new lumbar baclofen catheter due to an infection in her lower back precluding safe and efficacious catheter placement. It was decided the patient would benefit from intrathecal baclofen administered in the prepontine space as a means to avoid a lumbar catheter and thus bypass this prior infection site. An endoscopic third ventriculostomy (ETV) was performed with the endoscope and the distal end of the baclofen pump catheter was fed through this ETV into the prepontine space. Placement in the prepontine space was confirmed by a follow-up head computed tomography. There was a significant improvement in autonomic symptoms and spasticity. By postoperative day 5, the patient was surgically and medically cleared for discharge.

Conclusion:

In cases of severe baclofen withdrawal due to dysfunctional pumps, immediate reversal is preferred but may not be feasible due to factors such as infection. This case report has demonstrated that prepontine catheter placement can be effective for the administration of baclofen to reverse withdrawal symptoms in these types of patients.

Characterizing Baclofen Withdrawal: A National Survey of Physician Experience

OBJECTIVE

We studied physicians' opinions and experiences concerning clinical concerns, perceived severity, occurrence, and management of baclofen withdrawal due to abrupt discontinuation.

METHODS

A nationwide 26-question electronic survey was distributed via e-mail to physicians (N = 952) representing varying specialties who manage spasticity with baclofen. A total of 110 physicians provided responses to the survey (response rate = 11.6%). Results were evaluated using descriptive statistics.

RESULTS

Withdrawal from both oral and intrathecal (IT) baclofen was recognized as a significant concern and was observed by most respondents. However, approximately 75% and 35% of respondents or their clinic sites lack established management protocols for managing anticipated interruption of oral or IT baclofen, respectively.

CONCLUSIONS

These findings highlight the need for further research on and the development of guidelines for the prevention and treatment of baclofen withdrawal. The results of this survey, along with a systematic literature review and multidisciplinary stakeholder input, may be helpful in establishing guidelines for the treatment and prevention of baclofen withdrawal.

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.

Simultaneous explantation and implantation of intrathecal pumps: a case series

OBJECTIVE

Intrathecal drug delivery devices (IDDDs) are a mainstay in the treatment of spasticity and refractory pain. While these devices have been shown to greatly improve the quality of life for patients, they also have a high perioperative complication and failure rate. A major complication of IDDD implantation is infection. The current standard of care in the treatment of IDDD infection necessitates that the pump be explanted and the infection treated prior to implantation of a new IDDD. This process leads to long hospital stays, interruptions in optimal medical management, and a high risk for dangerous drug withdrawals. The authors describe a technique that allows for the explantation of the infected pump and implantation of a new pump concurrently, which they have named the "Turner Switch" technique in honor of its inventor.

METHODS

The authors conducted a retrospective analysis of cases of infected IDDDs in which patients underwent simultaneous explantation of the infected pump and implantation of a new pump. Demographics and clinical data were collected.

RESULTS

Data from a total of 17 patients (11 male, 6 female) who underwent simultaneous IDDD explantation and implantation to treat infections were analyzed from a 3-year period. No patients experienced infection of the newly implanted pump or catheter. Of the 17 patients, 14 (82.4%) had baclofen pumps to treat spasticity and 3 (17.6%) had fentanyl pumps to treat chronic pain. The median hospital stay was 7 days, with 16 of 17 (94.1%) patients able to be discharged home or to a facility with a level of care similar to their preoperative care. All patients ultimately experienced complete resolution of their initial infections. Five patients (29.4%) required a return to the operating room within the next 5 months (for repair of a CSF leak in 2 cases, for treatment of infection at the old pump site in 2 cases, and for treatment of a CSF leak compounded with infection in 1 case). No patient experienced infection of the newly implanted pump or catheter.

CONCLUSIONS

IDDD infections represent a large portion of morbidity associated with these devices. The current standard of care for deep pump infections requires pump explantation and a course of antibiotics prior to reimplantation of the IDDD. The authors demonstrate the effectiveness of a procedure involving simultaneous explantation of an infected pump and implantation of a new pump on the contralateral side in the treatment of IDDD infections.

Baclofen Withdrawal: A Cause of Prolonged Fever in the Intensive Care Unit

We report a case of baclofen withdrawal syndrome resulting from oral baclofen underdosing. A 24-year-old woman with type 1 neurofibromatosis receiving long-term baclofen therapy was admitted with presumed pneumonia which was successfully treated with antibiotics. The patient continued to have fever and autonomic instability without evidence of infection which entirely resolved within 24 hours of reinstitution of full preadmission dosing of oral baclofen. Baclofen withdrawal syndrome resulting from underdosing of oral baclofen should be considered as a potential source of prolonged fever in the intensive care unit.

Intrathecal Baclofen Injection to Avoid Withdrawal in a Multiple Sclerosis Patient Undergoing Lumbar Spine Surgery: A Case Report

Spasticity of spinal or cerebral origin is frequently treated with baclofen. Treatment interruption initially results in rebound spasticity; life-threatening withdrawal symptoms may follow. Severe rebound spasticity of leg muscles occurred in a multiple sclerosis patient after a 10-hour long perioperative pause of oral baclofen intake. In a subsequent spine surgery, recurrence was prevented by substituting a cumulative 12-hour oral baclofen dose with an intraoperative intrathecal injection. Administration of intrathecal baclofen during prolonged surgery in patients dependent on oral baclofen may improve patient comfort and prevent early withdrawal symptoms. The most optimal conversion ratio from oral to intrathecal baclofen is still undetermined.

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.

Potential for Intrathecal Baclofen in Treatment of Essential Tremor

INTRODUCTION

Essential tremor (ET) is the most common movement disorder of adults, affecting an estimated 7 million Americans. Symptoms of ET range from slightly noticeable to debilitating, with 1 cohort study finding 15% of patients were forced into early retirement. Additionally, depression has also been correlated with the severity of disability of ET. Treatment options include propranolol and primidone. Current treatment options are not very effective, with more than half (56.3%) of patients discontinuing medications because of no changes in symptoms.

METHODS

Unfortunately, there is a relative void and controversy in the literature explaining ET pathophysiology; however, the gamma-aminobutyric acid (GABA) hypothesis is the strongest. We conducted a PubMed search on 30 September 2015 with no time constraints using the search terms "essential tremor" and "baclofen," which resulted in a total of 5 articles.

RESULTS

Neurohistopathologic studies have demonstrated decreased GABA-A and GABA-B receptors in the cerebellar cortex of ET patients. GABA, the major inhibitory neurotransmitter in the central nervous system, is proposed to have an inhibitory effect on pacemaker output activity of the cerebello-thalamo-cortical pathway, with lower receptors resulting in decreased inhibition of baseline tremors. Tariq et al showed delayed onset and intensity of tremor with oral administration of R-baclofen in a mouse model of ET.

CONCLUSION

With a better side-effect profile and success in a physiologically related condition, we propose more clinical trials and research be carried out on intrathecal baclofen as a potential treatment option, especially drug refractory ET, so as to increase the quality of life of this patient population.

A Randomized Dose Escalation Study of Intravenous Baclofen in Healthy Volunteers: Clinical Tolerance and Pharmacokinetics

BACKGROUND

Abrupt discontinuation of baclofen can result in a potentially severe withdrawal syndrome. The current treatment for baclofen withdrawal is inadequate, resulting in a critical need to develop an alternative method to prevent or treat this withdrawal syndrome.

OBJECTIVE

To evaluate the safety profile and pharmacokinetics of oral (PO) and investigational intravenous (IV) baclofen formulations at clinically relevant doses.

DESIGN

Randomized, open-label, dose-escalation, crossover study.

SETTING

Contract Research Organization (CRO).

METHODS

Three cohorts of 12 healthy adults received single doses of PO baclofen (10 mg, 15 mg or 20 mg) and 10-minute infusions of IV baclofen (7.5 mg, 11.5 mg, or 15 mg) with a minimum 48-hour wash-out period. The third cohort also received a 60-minute infusion of 15 mg IV baclofen after an additional 48-hour wash-out period.

MAIN OUTCOME MEASURES

Subjects were observed in a CRO for 24 hours after each dose of baclofen, and were assessed for nystagmus, ataxia, and sedation. Blood samples were collected from 0 to 24 hours and analyzed for baclofen concentration using high-performance liquid chromatography-mass spectroscopy. Noncompartmental pharmacokinetic analyses were performed. Dose linearity and proportionality was assessed using 2-way repeated-measures analysis of variance and a power model analysis.

RESULTS

None of the PO or IV doses resulted in significant sedation compared to baseline. All subjects could perform tandem gait after each baclofen dose. The most common side effect, transient mild nystagmus, was noted in 4 of 36 and in 13 of 36 subjects after PO and IV administration, respectively. This was likely related to increased maximum concentrations (C_max). After the 20 mg PO and 15 mg IV doses, mean C_max levels were 255 and 722 ng/mL and half-lives were 5.24 and 5.79 hours for PO and IV baclofen, respectively. The mean oral bioavailability for the 20-mg PO dose was approximately 80%.

CONCLUSIONS

All PO and IV doses of baclofen were well tolerated clinically. The 80% bioavailability suggests that a 20% reduction in IV dose will produce comparable total drug exposures to that of the PO dose. When PO therapy is interrupted, bridging with IV baclofen may be feasible.

LEVEL OF EVIDENCE

II.

Oral Baclofen Withdrawal Resulting in Progressive Weakness and Sedation Requiring Intensive Care Admission

Baclofen is a common medication used as a muscle relaxant and antispasmodic. Baclofen-withdrawal syndrome has many symptoms such as sedation, somnolence, and weakness but can include psychological symptoms. We present a 62-year-old female whose oral baclofen was not continued at a skilled nursing facility after discharge following inpatient surgery that led to the development of altered mental status and respiratory insufficiency necessitating intensive care unit admission. Abrupt cessation of baclofen, no matter the mode of administration to the patient, can lead to baclofen-withdrawal syndrome.

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.

Spinal Surgery and Abrupt Intrathecal Baclofen Withdrawal

Abrupt cessation of intrathecal baclofen can lead to a serious withdrawal syndrome. The anesthesiologist must be prepared to avoid intraoperative interruption of baclofen delivery before starting spinal surgery and to recognize and treat the symptoms of baclofen withdrawal in the immediate postoperative period.

Intrathecal Baclofen therapy in Germany: Proceedings of the IAB-Interdisciplinary Working Group for Movement Disorders Consensus Meeting

Continuous intrathecal Baclofen application (ITB) through an intracorporeal pump system is widely used in adults and children with spasticity of spinal and supraspinal origin. Currently, about 1200 new ITB pump systems are implanted in Germany each year. ITB is based on an interdisciplinary approach with neurologists, rehabilitation specialists, paediatricians and neurosurgeons. We are presenting the proceedings of a consensus meeting organised by IAB-Interdisciplinary Working Group for Movement Disorders. The ITB pump system consists of the implantable pump with its drug reservoir, the refill port, an additional side port and a flexible catheter. Non-programmable pumps drive the Baclofen flow by the reservoir pressure. Programmable pumps additionally contain a radiofrequency control unit, an electrical pump and a battery. They have major advantages during the dose-finding phase. ITB doses vary widely between 10 and 2000 μg/day. For spinal spasticity, they are typically in the order of 100-300 μg/day. Hereditary spastic paraplegia seems to require particularly low doses, while dystonia and brain injury require particularly high ones. Best effects are documented for tonic paraspasticity of spinal origin and the least effects for phasic muscle hyperactivity disorders of supraspinal origin. Oral antispastics are mainly effective in mild spasticity. Botulinum toxin is most effective in focal spasticity. Myotomies and denervation operations are restricted to selected cases of focal spasticity. Due to its wide-spread distribution within the cerebrospinal fluid, ITB can tackle wide-spread and severe spasticity.

Preliminary results of chronic intrathecal therapy in treatment of spastic syndromes of various etiologies

OBJECTIVE

To estimate the effectiveness of the chronic intrathecal baclofen infusion (ITB) for the treatment of botuloresistant spastic disorders.

MATERIAL AND METHODS

ITB have been performed in 15 cases of spastic disorders. In 8 cases spasticity was the result of cerebral palsy, 5 - spinal cord injure, 1 - cerebral injure, 1 - pyogenic spinal epiduritis. The results of surgical treatment were estimated with the Ashworth, GMFM-88 and Arens scales. These data have been exposed statistically analysis.

RESULTS

Significantly decrease of spasticity have been revealed in most cases: from 4.26±0.7 points before the operation to 1.8±0.67 points after the operation (p<0.004). In 8 cases we have observed improvement in motor functions.

CONCLUSION

ITB is an effective procedure which leads to decreasing of spasticity, incree of movement volume and improvement in motor functions in patients with spastic disorders.

A pilot study assessing pharmacokinetics and tolerability of oral and intravenous baclofen in healthy adult volunteers

Our objective was to characterize baclofen pharmacokinetics and safety given orally and intravenously. Twelve healthy subjects were enrolled in a randomized, open-label, crossover study and received single doses of baclofen: 3 or 5 mg given intravenously and 5 or 10 mg taken orally with a 48-hour washout. Blood samples for baclofen analysis were collected pre-dose and at regular intervals up to 24 hours post-dose. Clinical response was assessed by sedation scores, ataxia, and nystagmus. Mean absolute bioavailability of oral baclofen was 74%. Dose-adjusted areas under the curve between the oral and intravenous arms were statistically different (P = .0024), whereas area under the curve variability was similar (coefficient of variation: 18%-24%). Adverse effects were mild in severity and not related to either dose or route of administration. Three- and 5-mg intravenous doses of baclofen were well tolerated. Seventy-four percent oral bioavailability indicates that smaller doses of intravenous baclofen are needed to attain comparable total drug exposures.

Cardiac arrest due to baclofen withdrawal syndrome

A 41-year-old man presented with postcervical traumatic complete quadriparesis under intrathecal baclofen therapy (ITB) for refractory spasticity. Less than 24 h after having his baclofen pump substituted, he develops hyperthermia, seizures, cognitive depression, acute hypoxaemic respiratory failure and cardiovascular instability leading to mechanical ventilation and vasopressor support. He was transferred to an intensive care unit with diagnosis of community-acquired pneumonia leading to septic shock. He evolved with progressive clinical worsening and multisystem organ failure and cardiac arrest in non-shockable rhythm (pulseless electrical activity)--4 min resuscitation with return of spontaneous circulation. Considering the possible diagnosis of baclofen withdrawal syndrome and, in suspicion of ITB delivery disruption, the catheter system was surgically explored and a leaking tubule attachment was found. Despite aggressive cardiovascular, respiratory and renal support therapy, clinical improvement occurred only after restoration of intrathecal drug delivery. He was discharged from the hospital after 56 days, having returned to baseline status.

Assessing alcohol versus baclofen withdrawal syndrome in patients treated with baclofen for alcohol use disorder

Baclofen is a γ-aminobutyric acid B (GABA-B) receptor agonist that is approved for spasticity. Recently, the off-label use of baclofen for alcohol use disorder (AUD) has increased. However, baclofen is known to induce a neuroadaptation process, which may be identified by the occurrence of a specific baclofen withdrawal syndrome (BWS), that is, confusion, agitation, seizures, and delirium. The same set of symptoms characterizes alcohol withdrawal syndrome (AWS), which could lead to mistaking BWS for AWS in some situations. We report the cases of 3 patients under a chronic baclofen treatment for AUD. The patients emergently presented with a clinical state of confusion that was initially diagnosed and treated as AWS, with limited effect of benzodiazepines. Retrospectively, using a validated algorithm for assessing drug-induced withdrawal, we determined that all of these clinical cases were consistent with BWS. Both AWS and BWS should be considered in the case of acute confusion or delirium occurring in patients treated with baclofen for AUD. Moreover, further research should investigate to what extent GABA-A and GABA-B induce shared or distinct neuroadaptation processes and withdrawal syndromes.

Occurrence of adverse events in long-term intrathecal baclofen infusion: a 1-year follow-up study of 158 adults

OBJECTIVE

To assess the frequency and types of adverse events (AEs) related to intrathecal baclofen (ITB) therapy in adults, and associated risk factors.

DESIGN

A prospective, observational cohort study of adults followed up from January 1 to December 31, 2010.

SETTING

A neurologic rehabilitation department in a university hospital.

PARTICIPANTS

All consecutive adult subjects (N=158) receiving ITB via a pump, either implanted or followed up during the study period.

INTERVENTION

Not applicable.

MAIN OUTCOME MEASURES

Frequency and type of AEs.

RESULTS

In 2010, 158 subjects were followed up for ITB therapy, of whom 128 were implanted before 2010 (nonsurgical subjects), and 30 underwent implantation in 2010 (surgical subjects). Of these 30 subjects, 20 were "newly implanted" and 10 were "replacements." The most frequent pathologic disorders were spinal cord injury (42%) and multiple sclerosis (28%). Twenty-eight subjects (18%) experienced a total of 38 AEs. The rate of AEs was .023 per month of ITB treatment. AEs were related to the surgical procedure in 53% of cases, to the device in 29% (predominantly catheter dysfunctions), and to adverse effects of baclofen in 18%. AEs related to the surgical incision (scar complications and collections) were more frequent in replacement than newly implanted subjects (P=.009). No significant association between occurrence of an AE and subject characteristics (age, gait capacity, spinal vs cerebral spasticity, duration of ITB therapy follow-up) was found. Nearly half of the AEs were serious, extending admission time by a mean of 16 days. No AE induced long-term morbidity or death.

CONCLUSIONS

The AE rate was relatively low in this cohort. This has to be balanced against the clinical, functional, and quality-of-life improvements, which are expected from ITB therapy.

Patients with neuromuscular disorder

This article describes the preoperative preparation of patients with neuromuscular disorders. These entities are a relatively rare and diverse group of diseases that can affect various organ systems in addition to the central nervous system. The anesthetic implications for the various comorbidities are varied and can be profound. These patients should be optimized before surgery, with the involvement of a multidisciplinary team of specialists.

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.

Efficacy and tolerability of baclofen in substance use disorders: a systematic review

BACKGROUND

It has been reported that baclofen, a drug used in the treatment of spasticity, reduces the severity of withdrawal symptoms and substance use disorders (SUDs) for some psychoactive drugs.

AIMS AND METHODS

To evaluate the effectiveness and safety of baclofen in the treatment of withdrawal syndrome and/or SUDs, providing (1) an outline of its pharmacological features; (2) a summary of studies that have suggested its possible effectiveness in the treatment of SUDs, and (3) a review of randomized, controlled trials (RCTs) on baclofen and SUDs.

RESULTS

Baclofen tolerability is generally considered to be good. Eleven RCTs investigated its effectiveness in the treatment of SUDs. Of these, 5 RCTs found that baclofen is effective, 5 RCTs found that it is ineffective and the results of 1 RCT were not appreciable because it did not achieve the preplanned level of participation.

CONCLUSIONS

The number of RCTs on baclofen and SUDs is still low, and their results are divergent. Further RCTs should be undertaken, particularly with higher doses of baclofen. Its administration may be suggested in patients who fail to respond to other approved drugs or who are affected by liver disease that prevents their administration, or in patients affected by SUDs for which no approved drugs are available. Treatment should be conducted under strict medical supervision.

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.

Indium 111 diethylenetriamine pentaacetic acid scintigraphy in the identification and management of intrathecal pump malfunction

BACKGROUND

Intrathecal drug-delivery systems have become widely used tools in the management of refractory chronic pain and spasticity. Because increasing numbers of patients are using these systems, rehabilitation specialists frequently are the initial care providers who identify clinical signs and symptoms indicating possible complications relating to the implanted system. Identification of a pump malfunction often presents a diagnostic challenge. Distinguishing among progression of disease, new organic problems, and/or drug-device complications is critical. The use of nuclear medicine indium 111 diethylenetriamine pentaacetic acid (DTPA) studies represents a highly effective, straightforward, minimally invasive way to assess implant function and drug distribution.

OBJECTIVE

To identify patients with suspected intrathecal pump malfunction and to determine whether the use of indium 111 DTPA is effective in identifying the source of failure.

DESIGN

A retrospective review was performed from 2011 to 2012.

SETTING

The study was performed at Georgia Health Sciences University.

PATIENTS

The 23 selected patients had implanted devices for either spasticity or pain and were experiencing symptoms of a possible pump malfunction despite normal radiographic imaging. Twenty-four scintigraphic studies were performed, with malfunction documented in 19 patients.

METHODS

A standard refill technique was used to inject 0.3 mL of indium 111 DTPA into the pump reservoir. Radionuclide images were reviewed at varying time points up to 48 hours after injection. The extent of radionuclide progression from the pump reservoir to the intrathecal space was evaluated. In cases in which a problem with the implant was identified, correlation with operative findings is described.

RESULTS

Normal results of studies ultimately correlated with other clinical issues and confirmed an alternative etiology for the clinical changes noted. In studies with abnormal results, several patterns of failure were identified: restriction of the radionuclide to the pump reservoir, extravasations of tracer into the pump subcutaneous pocket, failure of the tracer to migrate from the subcutaneous catheter to the intrathecal space, and pooling of the tracer in the subcutaneous tissues. In all cases, surgical findings confirmed the suspected mechanism of malfunction as determined by the study.

CONCLUSIONS

Indium 111 DTPA scintigraphy is a safe, straightforward way to identify and characterize clinical changes associated with intrathecal drug-delivery systems and to guide appropriate and clinical surgical management.

Baclofen-enhanced spinal cord stimulation and intrathecal baclofen alone for neuropathic pain: Long-term outcome of a pilot study

In a previously published pilot study, we addressed the possibility to increase the effectiveness of spinal cord stimulation (SCS) applied for neuropathic pain by using adjunct pharmacological therapy. This combined treatment approach was a direct spin-off from animal experiments aiming at the exploration of transmitter and receptor mechanisms involved in the pain relieving effect of SCS. Out of 48 patients with neuropathic pain of peripheral origin responding poorly to SCS, seven received pumps for intrathecal baclofen (GABA-B receptor agonist) delivery together with SCS, and four had pumps alone. In order to assess the long-term effect a follow-up has been performed, with an average, total treatment time of 67 months. At the follow-up the remaining nine patients still enjoy about the same pain relief as initially, but with a mean, further dose increase of about 30%. This study demonstrates that a deficient SCS effect in neuropathic pain may be considerably improved by intrathecal baclofen administration, and that this enhanced effect persists for a long-time. On-going and future animal studies may provide new and even more efficient pharmaceutical candidates for such combined therapy.

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.

Intrathecal baclofen therapy: benefits and complications

BACKGROUND

Spasticity and dystonia in children with cerebral palsy has been treated with intrathecal baclofen therapy (ITB) at the Royal Children's Hospital, Melbourne, Australia (RCH) since 1999.

METHODS

The records of children having received or still receiving ITB during the period September 1999 until August 2005 were studied to evaluate complications and side effects. Parents answered a questionnaire focused on the health and functional impact in the children.

RESULTS

There were 18 first insertions of pumps, 6 removals, and 4 reinsertions. The longest treatment was 5 years and 11 months and was still ongoing. Seventeen complications occurred in 14 out of 18 children. Despite the high complication rate and the lack of significant functional improvement, 11 out of 12 parents agreed that ITB was beneficial.

CONCLUSION

ITB treatment at RCH over the years has resulted in some complications, mostly occurring shortly after pump insertion. For the majority of children there are substantial benefits.

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.

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.

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.

[Continuous infusion of baclofen and an antibiotic for treating meningitis related to refilling of an intrathecal infusion pump reservoir]

Baclofen via intrathecal infusion pump is a widely used treatment severe spasticity. Complications are rare and usually mild, though they can also be serious. The sudden discontinuation of intrathecal baclofen may have significant adverse effects. We report the case of a 59-year-old man with chronic spasticity and torsion dystonia who developed meningitis due to Staphylococcus epidermidis due to contamination of the intrathecal, infusion pump reservoir during refilling. It was decided to treat the patient by administering vancomycin through the pump, together with the baclofen. We believe that changing the intrathecal perfusion pump is not necessary as the first measure to take in these cases. Combined infusion of baclofen and an antibiotic through the pump makes it possible to maintain antispastic treatment, sterilize the pump reservoir and tubes, and effectively treat infections that develop during use of these systems.

Cerebral palsy

Cerebral palsy (CP) is the leading cause of childhood disability. This article reviews common presentations of CP and its possible causes. The management of common problems seen in affected children is discussed in a system-based approach. Many treatment options are available for CP, with varying degrees of evidence and acceptance. As individuals who have CP transition into adulthood, they face unique issues that are not well recognized in the medical community. This article briefly reviews the psychosocial impact of this chronic disease on individuals and their caregivers and family.

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.

Chemically Induced Seizures

Drug- and toxin-associated seizures (DTS) may result from exposure to a wide variety of agents. Most DTS can be managed with supportive care. First-line anticonvulsant therapy should include benzodiazepines, unless agents require a specific antidote. Phenytoin is generally not expected to be useful for DTS and in some instances may be harmful. In this article the authors discuss the pathophysiology of DTS, the potential differential diagnosis, and the clinical presentation. They also review selected agents that cause DTS and provide an overview of how the clinician should approach the management of patients who have DTS.

Drug- and toxin-associated seizures

Drug- and toxin-associated seizures may result from exposure to a wide variety of agents. Obtaining a comprehensive history behind the exposure is generally more helpful than diagnostic testing. Most DTS may be managed with supportive care, including benzodiazepines, except in the case of agents that require a specific intervention or antidote.

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.

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.

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.