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

Evaluating drug withdrawal syndrome risks through food and drug administration adverse event reporting system: a comprehensive disproportionality analysis

Objective

The study aims to identify the drugs associated with drug withdrawal syndrome in the Food and Drug Administration Adverse Event Reporting System (FAERS) and estimate their risks of causing withdrawal syndrome.

Methods

All the data were collected from FAERS from the first quarter of 2004 to the third quarter of 2023. Disproportionality analyses of odds ratio (ROR) and proportional reported ratio were conducted to identify potential adverse effects signal of drug withdrawal syndrome.

Results

A total of 94,370 reports related to withdrawal syndrome from the data. The top 50 drugs with most frequency reported were analyzed, and 29 exhibited a positive signal based on the number of reports. The top three categories of drugs with positive signals included opioids, antidepressant drugs and antianxiety drugs. Other classifications included opioid antagonist, muscle relaxant, antiepileptic drugs, analgesics, hypnotic sedative drugs and antipsychotic drugs.

Conclusion

Our analysis of FAERS data yielded a comprehensive list of drugs associated with withdrawal syndrome. This information is vital for healthcare professionals, including doctors and pharmacists, as it aids in better recognition and management of withdrawal symptoms in patients undergoing treatment with these medications.

Intrathecal baclofen efficacy for managing motor function and spasticity severity in patients with cerebral palsy: a systematic review and meta-analysis

BACKGROUND

Spasticity can significantly affect a patient's quality of life, caregiver satisfaction, and the financial burden on the healthcare system. Baclofen is one of only a few options for treating spasticity. The purpose of this study is to investigate the impact of intrathecal baclofen (ITB) therapy on severe40.23 spasticity and motor function in patients with cerebral palsy.

METHODS

We conducted a systematic review in PubMed, Scopus, Ovid, and the Cochrane Library in accordance with the PRISMA guidelines. We included studies based on eligibility criteria that included desired participants (cerebral palsy patients with spasticity), interventions (intrathecal baclofen), and outcomes (the Ashworth scales and the Gross Motor Function Measure [GMFM]). The within-group Cohen's d standardized mean differences (SMD) were analyzed using the random effect model.

RESULTS

We screened 768 papers and included 19 in the severity of spasticity section and 6 in the motor function section. The pre-intervention average spasticity score (SD) was 3.2 (0.78), and the post-intervention average score (SD) was 1.9 (0.72), showing a 40.25% reduction. The SMD for spasticity reduction was - 1.7000 (95% CI [-2.1546; -1.2454], p-value < 0.0001), involving 343 patients with a weighted average age of 15.78 years and a weighted average baclofen dose of 289 µg/day. The SMD for the MAS and Ashworth Scale subgroups were - 1.7845 (95% CI [-2.8704; -0.6986]) and - 1.4837 (95% CI [-1.8585; -1.1088]), respectively. We found no relationship between the participants' mean age, baclofen dose, measurement time, and the results. The pre-intervention average GMFM (SD) was 40.03 (26.01), and the post-intervention average score (SD) was 43.88 (26.18), showing a 9.62% increase. The SMD for motor function using GMFM was 0.1503 (95% CI [0.0784; 0.2223], p-value = 0.0030), involving 117 patients with a weighted average age of 13.63 and a weighted average baclofen dose of 203 µg/day. In 501 ITB implantations, 203 medical complications were reported, including six new-onset seizures (2.96% of medical complications), seven increased seizure frequency (3.45%), 33 infections (16.26%), eight meningitis (3.94%), and 16 cerebrospinal fluid leaks (7.88%). Delivery system complications, including 75 catheter and pump complications, were also reported.

CONCLUSION

Despite the risk of complications, ITB has a significant impact on the reduction of spasticity. A small but statistically significant improvement in motor function was also noted in a group of patients.

Calcification of the pump pouch in patients receiving ITB therapy: A rare complication affecting refill procedure - Analysis of two cases

BACKGROUND

Intrathecal baclofen therapy (ITB) is an effective treatment for reducing spasticity but can be associated with various complications, including infection and implant malfunction.

METHODS

This retrospective cohort study analyzed refill reports, complications, and functional outcomes in 40 consecutive patients with intractable spasticity or dystonia undergoing ITB.

RESULTS

Among the 40 patients, 8 experienced complications, including two cases of calcification of the baclofen pump pouch and surrounding tissue, a rare complication not extensively described in the literature.

DISCUSSION

Calcification, in addition to port access difficulties, could lead to drug delivery failure. We hypothesize that calcification may result from microtrauma or needlestick injury to the subcutaneous tissue and muscle fascia. The length of time the pump stays in the pocket could also contribute to favoring this phenomenon.

CONCLUSION

As the number of patients receiving ITB increases, physicians must be aware of potential life-threatening complications. The risk of pouch calcification should be further investigated and considered in managing patients undergoing ITB, as it could significantly impact patient care.

Adults with Cerebral Palsy: Navigating the Complexities of Aging

The goal of this narrative review is to highlight the healthcare challenges faced by adults with cerebral palsy, including the management of long-term motor deficits, difficulty finding clinicians with expertise in these long-term impairments, and scarcity of rehabilitation options. Additionally, this narrative review seeks to examine potential methods for maintaining functional independence, promoting social integration, and community participation. Although the brain lesion that causes the movement disorder is non-progressive, the neurodevelopmental disorder worsens from secondary complications of existing sensory, motor, and cognitive impairments. Therefore, maintaining the continuum of care across one's lifespan is of utmost importance. Advancements in healthcare services over the past decade have resulted in lower mortality rates and increased the average life expectancy of people with cerebral palsy. However, once they transition from adolescence to adulthood, limited federal and community resources, and health care professionals' lack of expertise present significant obstacles to achieving quality healthcare and long-term benefits. This paper highlights the common impairments seen in adults with cerebral palsy. Additionally, it underscores the critical role of long-term healthcare and management to prevent functional decline and enhance quality of life across physical, cognitive, and social domains.

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

BACKGROUND

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Intrathecal and Oral Baclofen Use in Adults With Spinal Cord Injury: A Systematic Review of Efficacy in Spasticity Reduction, Functional Changes, Dosing, and Adverse Events

OBJECTIVE

To examine the efficacy, dosing, and safety profiles of intrathecal and oral baclofen in treating spasticity after spinal cord injury (SCI).

DATA SOURCES

PubMed and Cochrane Databases were searched from 1970-2018 with keywords baclofen, spinal cord injury, and efficacy.

STUDY SELECTION

The database search yielded 588 sources and 10 additional relevant publications. After removal of duplicates, 398 publications were screened.

DATA EXTRACTION

Data were extracted using the following population, intervention, comparator, outcomes, and study designs criteria: studies including adult patients with SCI with spasticity; the intervention could be oral or intrathecal administration of baclofen; selection was inclusive for control groups, surgical management, rehabilitation, and alternative pharmaceutical agents; outcomes were efficacy, dosing, and adverse events. Randomized controlled trials, observational studies, and case reports were included. Meta-analyses and systematic reviews were excluded.

DATA SYNTHESIS

A total of 98 studies were included with 1943 patients. Only 4 randomized, double-blinded, and placebo-controlled trials were reported. Thirty-nine studies examined changes in the Modified Ashworth Scale (MAS; 34 studies) and Penn Spasm scores (Penn Spasm Frequency; 19 studies), with average reductions of 1.7±1.3 and 1.6±1.4 in individuals with SCI, respectively. Of these data, a total of 6 of the 34 studies (MAS) and 2 of the 19 studies (Penn Spasm Frequency) analyzed oral baclofen. Forty-three studies addressed adverse events with muscle weakness and fatigue frequently reported.

CONCLUSIONS

Baclofen is the most commonly-prescribed antispasmodic after SCI. Surprisingly, there remains a significant lack of large, placebo-controlled, double-blinded clinical trials, with most efficacy data arising from small studies examining treatment across different etiologies. In the studies reviewed, baclofen effectively improved spasticity outcome measures, with increased efficacy through intrathecal administration. Few studies assessed how reduced neural excitability affected residual motor function and activities of daily living. A host of adverse events were reported that may negatively affect quality of life. Comparative randomized controlled trials of baclofen and alternative treatments are warranted because these have demonstrated promise in relieving spasticity with reduced adverse events and without negatively affecting residual motor function.

Intravenous dantrolene in hypermetabolic syndromes: a survey of the U.S. Veterans Health Administration database

BACKGROUND

Intravenous dantrolene is often prescribed for hypermetabolic syndromes other than the approved indication of malignant hyperthermia (MH). To clarify the extent of and indications for dantrolene use in conditions other than MH, we sought to document current practices in the frequency, diagnoses, clinical characteristics and outcomes associated with dantrolene treatment in critical care settings.

METHODS

Inpatients receiving intravenous dantrolene from October 1, 2004 to September 30, 2014 were identified retrospectively in the U.S. Veterans Health Administration national database. Extracted data included; diagnoses of hypermetabolic syndromes; triggering drugs; dantrolene dosages; demographics; vital signs; laboratory values; in-hospital mortality; complications; and lengths of stay. Frequency and mortality of patients who did not receive dantrolene were obtained in selected diagnoses for exploratory comparisons.

RESULTS

Dantrolene was administered to 304 inpatients. The most frequent diagnoses associated with dantrolene treatment were neuroleptic malignant syndrome (NMS; N = 108, 35.53%) and sepsis (N = 47, 15.46%), with MH accounting for only 13 (4.28%) cases. Over half the patients had psychiatric comorbidities and received psychotropic drugs before dantrolene treatment. Common clinical findings in patients receiving dantrolene included elevated temperature (mean ± SD; 38.7 ± 1.3 °C), pulse (116.33 ± 22.80/bpm), respirations (27.75 ± 9.58/min), creatine kinase levels (2,859.37 ± 6,646.88 IU/L) and low pO₂ (74.93 ± 40.16 mmHg). Respiratory, renal or cardiac failure were common complications. Mortality rates in-hospital were 24.01% overall, 7.69% in MH, 20.37% in NMS and 42.55% in sepsis, compared with mortality rates in larger and possibly less severe groups of unmatched patients with MH (5.26%), NMS (6.66%), or sepsis (41.91%) who did not receive dantrolene.

CONCLUSIONS

In over 95% of cases, dantrolene administration was associated with diagnoses other than MH in critically-ill patients with hypermetabolic symptoms and medical and psychiatric comorbidities. Exploratory survey data suggested that the efficacy and safety of dantrolene in preventing mortality in hypermetabolic syndromes other than MH remain uncertain. However, randomized and controlled studies using standardized criteria between groups matched for severity are essential to guide practice in using dantrolene.

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.

Severe Case of Oral Baclofen Withdrawal Resulting in Mechanical Ventilation

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

Multiple Electroencephalogram Recordings for Monitoring the Evolution of Neurological Complications during Baclofen Withdrawal Syndrome

Baclofen withdrawal syndrome represents a clinical emergency that can lead to life-threatening complications. It is often a diagnostic challenge because of its nonspecific nature of presentation and degree of symptom overlap with other clinical diseases. Electroencephalography (EEG) might provide important supporting evidence when neurological complications are involved. We present the case of a 55-year-old woman with sudden onset of motor manifestations at the limbs and an altered mental status 24 hours after cessation of intrathecal baclofen administration, following the removal of the pump due to infection, in whom a computed tomography did not show any acute-onset brain injuries, and multiple EEG recordings were performed. The first EEG showed the presence of bilateral sharply contoured waves, in the absence of epileptic discharges and seizures. No correlation between motor manifestations and EEG changes were detected. This EEG pattern was considered to be the expression of an overexcitation of the central nervous system (CNS) due to the loss of baclofen inhibitory effects, excluding an epileptic origin of motor manifestations. Another EEG, performed 24 hours later, showed the presence of triphasic waves with severe generalised slowing, suggesting the presence of encephalopathy. The last EEG, performed 48 hours after the previous recording, when a recovered state of consciousness was already present, showed regression of the triphasic waves and a reorganisation of the background activity. In our case, repeated EEG evaluation allowed monitoring the evolution of acute encephalopathy developed during baclofen withdrawal syndrome, from the initial phase of CNS hyperexcitability, through the phase of metabolic encephalopathy, and to its resolution. This modality allowed for optimising the diagnostic-therapeutic management of the patient during her stay in the intensive care unit.

Probable Encephalopathy and Spasticity in a Multiple Sclerosis Patient Following Carbapenem Administration: A Case Report and Brief Literature Review

Purpose: The purpose of this case report is to describe spasticity and encephalopathy that developed in a multiple sclerosis patient following carbapenem administration. Summary: A 55-year-old female with multiple sclerosis developed spasticity and encephalopathy within 24 hours of meropenem and ertapenem administration. This was the second time that she had developed encephalopathy following carbapenem administration. The patient gradually recovered over four days following discontinuation of carbapenem therapy. Conclusion: Carbapenem neurotoxicity, a well-documented adverse effect, has been linked to several risk factors, including central nervous system lesions. Despite this, there is little evidence describing the risk of neurotoxicity in patients with multiple sclerosis. It is important to understand the potential adverse effects of carbapenems in specific patient populations to help guide appropriate treatment of infections.

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.

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.

Intrathecal baclofen, selective dorsal rhizotomy, and extracorporeal shockwave therapy for the treatment of spasticity in cerebral palsy: a systematic review

Cerebral palsy (CP) is a chronic congenital disorder as the result of abnormal brain development. Children suffering from CP often battle debilitating chronic spasticity, which has been the focus of recent academic literature. In this systematic review, the authors aim to update the current neuromodulation procedures for the treatment of spasticity associated with CP in all age groups. A systematic review following was conducted using PubMed from inception to 2020. After initial title and abstract screening, 489 articles were identified, and 48 studies met the inclusion criteria for this review. In total, a majority of the published articles of treatments for CP were reporting the use of selective dorsal rhizotomy (SDR) (54%), and the remainder were of intrathecal baclofen (ITB) pumps (29%) and extracorporeal shockwave therapy (ESWT) (17%). Each method was found to have improvement of spasticity at a rate that achieved statistical significance. ITB pump therapy is an all-encompassing method of treating spasticity in children from CP, as it allows for a less invasive treatment that can be titrated to individual patient needs; however, its disadvantages include its long-term maintenance requirements. SDR appears to be an effective method for permanent spasticity relief in young patients. ESWT is a more recent and innovative technique for offering relief of spasticity while being minimally invasiveness. Further studies are needed to establish optimal frequencies and sites of application for ESWT.

Drug-induced Hyperthermic Syndromes in Psychiatry

Hyperthermia, or extreme elevations in body temperature, can be life-threatening and may be caused by prescription drugs or illegal substances acting at a number of different levels of the neuraxis. Several psychotropic drug classes and combinations have been associated with a classic clinical syndrome of hyperthermia, skeletal muscle hypermetabolism, rigidity or rhabdomyolysis, autonomic dysfunction and altered mental status ranging from catatonic stupor to coma. It is critical for clinicians to have a high index of suspicion for these relatively uncommon drug-induced adverse effects and to become familiar with their management to prevent serious morbidity and mortality. Although these syndromes look alike, they are triggered by quite different mechanisms, and apart from the need to withdraw or restore potential triggering drugs and provide intensive medical care, specific treatments may vary. Clinical similarities have led to theoretical speculations about common mechanisms and shared genetic predispositions underlying these syndromes, suggesting that there may be a common “thermic stress syndrome” triggered in humans and animal models by a variety of pharmacological or environmental challenges.

Principles of Pharmacotherapy of Seizures and Status Epilepticus

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

The neuroleptic malignant syndrome-a systematic case series analysis focusing on therapy regimes and outcome

INTRODUCTION

Neuroleptic malignant syndrome (NMS) is a rare, potentially life-threatening antipsychotic-associated disorder that requires an efficient and timely therapy. The aim of the study was to compare the effectiveness of different NMS therapies and to analyze its outcome depending on NMS severity.

METHOD

Systematic search for NMS cases in biomedical databases. The focus of the analysis was on therapy with dantrolene, bromocriptine, and electroconvulsive therapy (ECT) when each was compared with symptomatic therapy. Primary outcomes were the survival rate and the duration of treatment.

RESULT

405 case reports were included. Overall, no statistically significant differences regarding mortality rate or duration of treatment were found between dantrolene, bromocriptine, or ECT compared to supportive care. A subgroup analysis regarding NMS severity showed that the mortality under specific NMS pharmacotherapy (dantrolene, bromocriptine) and under ECT was significantly lower than under purely symptomatic therapy in severe NMS (P = 0.018). The difference was not significant in mild and moderate cases.

DISCUSSION

An overall superiority of the specific NMS therapy (dantrolene, bromocriptine, and ECT) was not found in this study. When regarding severity classification, specific therapies were superior but only in severe cases, and ECT showed the lowest mortality rate. In previous case series, an effect on survival or the duration of the disease could only be observed in part for specific therapies, but the evidence available is inconsistent. The results of this study support our hypothesis that NMS treatment with dantrolene, bromocriptine, and ECT is advantageous over purely symptomatic therapy in severe NMS cases.

Point-of-Care Procedures in Physiatry: Practice Considerations During the Covid-19 Pandemic

Coronavirus disease 2019 is an active pandemic that has required rapid conversion of practice patterns to mitigate disease spread. Although recommendations have been released for physicians to postpone elective procedures, the utility of common physiatry procedures and their infectious risk profile have yet to be clearly delineated. In this article, we describe an update on existing national recommendations and outline considerations as practitioners and institutions strive to meet the needs of patients with disabilities.

Classics in Chemical Neuroscience: Baclofen

Baclofen, β-(4-chlorophenyl)-γ-aminobutyric acid, holds a unique position in neuroscience, remaining the only U.S. Food and Drug Administration (FDA) approved GABA_B agonist. While intended to be a more brain penetrant, i.e, ability to cross the blood-brain barrier (BBB), version of GABA (γ-aminobutyric acid) for the potential treatment of epilepsy, baclofen's highly efficacious muscle relaxant properties led to its approval, as a racemate, for the treatment of spasticity. Interestingly, baclofen received FDA approval before its receptor, GABA_B, was discovered and its exact mechanism of action was known. In recent times, baclofen has a myriad of off-label uses, with the treatment for alcohol abuse and drug addiction garnering a great deal of attention. This Review aims to capture the >60 year legacy of baclofen by walking through the history, pharmacology, synthesis, drug metabolism, routes of administration, and societal impact of this Classic in chemical neuroscience.

From quail to earthquakes and human conflict: a historical perspective of rhabdomyolysis

Rhabdomyolysis is a common cause of acute kidney injury, featuring muscle pain, weakness and dark urine and concurrent laboratory evidence of elevated muscle enzymes and myoglobinuria. Rhabdomyolysis is often seen in elderly and frail patients following prolonged immobilization, for example after a fall, but a variety of other causes are also well-described. What is unknown to most physicians dealing with such patients is the fascinating history of rhabdomyolysis. Cases of probable rhabdomyolysis have been reported since biblical times and during antiquity, often in the context of poisoning. Equally interesting is the link between rhabdomyolysis and armed conflict during the 20th century. Salient discoveries regarding the pathophysiology, diagnosis and treatment were made during the two world wars and in their aftermath. 'Haff disease', a form of rhabdomyolysis first described in 1920, has fascinated scientists and physicians alike, but the marine toxin causing it remains enigmatic even today. As a specialty, we have also learned a lot about the disease from 20th-century earthquakes, and networks of international help and cooperation have emerged. Finally, rhabdomyolysis has been described as a sequel to torture and similar forms of violence. Clinicians should be aware that rhabdomyolysis and the development of renal medicine are deeply intertwined with human history.

Caring for patients with pain during the COVID-19 pandemic: consensus recommendations from an international expert panel

Chronic pain causes significant suffering, limitation of daily activities and reduced quality of life. Infection from COVID-19 is responsible for an ongoing pandemic that causes severe acute respiratory syndrome, leading to systemic complications and death. Led by the World Health Organization, healthcare systems across the world are engaged in limiting the spread of infection. As a result, all elective surgical procedures, outpatient procedures and patient visits, including pain management services, have been postponed or cancelled. This has affected the care of chronic pain patients. Most are elderly with multiple comorbidities, which puts them at risk of COVID-19 infection. Important considerations that need to be recognised during this pandemic for chronic pain patients include: ensuring continuity of care and pain medications, especially opioids; use of telemedicine; maintaining biopsychosocial management; use of anti-inflammatory drugs; use of steroids; and prioritising necessary procedural visits. There are no guidelines to inform physicians and healthcare providers engaged in caring for patients with pain during this period of crisis. We assembled an expert panel of pain physicians, psychologists and researchers from North America and Europe to formulate recommendations to guide practice. As the COVID-19 situation continues to evolve rapidly, these recommendations are based on the best available evidence and expert opinion at this present time and may need adapting to local workplace policies.

Intrathecal Baclofen Overdose With Paradoxical Autonomic Features Mimicking Withdrawal

BACKGROUND

Intrathecal Baclofen (ITB) has become an increasingly common treatment for severe muscle spasticity associated with conditions such as cerebral palsy and spinal cord injury. Classically, withdrawal symptoms mimic symptoms of serotonin syndrome with hypertension, increased spasticity, clonus, hyperthermia, tachycardia, and possibly acute psychosis. Hypotension, muscle flaccidity, and respiratory depression are generally considered symptoms of toxicity or overdose.

CASE REPORT

We present the case of a male with recent ITB pump revision who presented with autonomic features suggestive of Baclofen withdrawal, while the remainder of his physical examination suggested appropriate medication dosing. Interrogation of the patient's ITB pump revealed normal function, and the patient had no clinical change with intravenous benzodiazepines, but his condition ultimately improved when his Baclofen dosing was decreased, indicating toxicity instead of withdrawal. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: As Baclofen pump use increases, the importance of recognizing these potentially life-threatening complications also increases. This case presents the emergency physician with an atypical presentation and emphasizes the importance of a thorough neurologic examination to diagnose patients accurately.

Dexmedetomidine for Acute Management of Intrathecal Baclofen Withdrawal

BACKGROUND

Intrathecal baclofen (ITB) is a mainstay of treatment for patients with chronic spasticity. Up to 40% of all patients receiving ITB experience overdose or withdrawal symptoms, which in the most severe cases can lead to multisystem organ failure and death. There is currently no well-established treatment for ITB withdrawal. One previous case report details an intubated pediatric patient who underwent baclofen pump removal in which dexmedetomidine was used in combination with other medications to prevent baclofen withdrawal.

CASE REPORT

We report a case of baclofen withdrawal where the decision was made to initiate a dexmedetomidine infusion, with subsequent improvement of the patient's hypertension and tachycardia. At no point during her stay did the patient require intubation for airway protection, and the patient was ultimately discharged to her previous nursing facility on hospital day 9 with no new neurologic deficits. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Emergency physicians should be aware of dexmedetomidine as a promising option for the treatment of ITB withdrawal in the acute setting. Although little evidence is currently present, dexmedetomidine was used successfully in this case, and should be considered as a temporizing treatment for ITB withdrawal. Dexmedetomidine holds promise in the management of ITB withdrawal compared to other previously described treatments, including oral baclofen, cyproheptadine, and dantrolene. In addition, dexmedetomidine has a superior safety profile compared to propofol or large doses of benzodiazepines. Further research will be useful in supporting the use of dexmedetomidine for this purpose.

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.

Meaningful Assessment in Patients with Acquired Brain Injuries

There are several key components to the meaningful and comprehensive assessment of patients with acquired brain injuries with respect to management of the upper motor neuron syndrome. Type of brain injury, trajectory of recovery, relevant concomitant complications, development of appropriate goals, and an understanding of resources available for patients are all factors to assess when developing a treatment plan. Using appropriate outcome measures will help monitor the efficacy of interventions and guide ongoing management of spasticity.

Intrathecal Baclofen Therapy-Practical Approach: Clinical Benefits and Complication Management

Intrathecal baclofen is an expanding accepted treatment for children with cerebral palsy and other causes of spasticity and dystonia. The aims of this review are therefore to (1) delineate the clinical benefits of intrathecal baclofen therapy in pediatric spasticity and dystonia and (2) increase awareness of the potential complications and emergency management measures of intrathecal baclofen therapy. A current literature review demonstrates the benefits and complications of this minimally invasive device. Practical guides for recognizing acute conditions and management recommendations are included. Intrathecal baclofen is increasingly being used to help individuals attain realistic functional goals. Therefore, families and health care professionals should be aware of potential complications, symptoms, and emergency management.

Autonomic dysfunction in the neurological intensive care unit

Autonomic dysfunction is common in neuro-critical care patients and may compromise the function of various organs. Among the many diseases causing or being associated with autonomic dysfunction are traumatic brain injury, cerebrovascular diseases, epilepsy, Guillain-Barré syndrome (GBS), alcohol withdrawal syndrome, botulism and tetanus, among many others. Autonomic dysfunction may afflict various organs and may involve hyper- or hypo-activity of the sympathetic or parasympathetic system. In this short overview, we address only a small number of neuro-intensive care diseases with autonomic dysfunction. In GBS, autonomic dysfunction is frequent and may account for increased mortality rates; rapid changes between sympathetic and parasympathetic hypo- or hyper-activity may cause life-threatening cardiovascular complications. Paroxysmal sympathetic hyperactivity occurs after brain injury, hypoxia and cerebrovascular and other events, causes paroxysmal tachycardia, hypertension, tachypnoea and hyperthermia and is associated with a poorer prognosis and prolonged intensive care treatment. Other, at times life-threatening autonomic complications with exaggerated sympathetic activity and compromised baroreflex sensitivity arise during the alcohol withdrawal syndrome triggered by abrupt cessation of alcohol consumption. Botulism and tetanus are examples of life-threatening autonomic dysfunction caused by bacterial neurotoxins. Common neurological diseases, such as epilepsy, stroke or subarachnoid haemorrhage, are also associated with autonomic dysfunction that can on occasion cause critical deterioration of disease severity and prognosis.

Neuromodulation in multiple sclerosis

Neuromodulation, or the utilization of advanced technology for targeted electrical or chemical neuronal stimulation or inhibition, has been expanding in several neurological subspecialties. In the past decades, immune-modulating therapy has been the main focus of multiple sclerosis (MS) research with little attention to neuromodulation. However, with the recent advances in disease-modifying therapies, it is time to shift the focus of MS research to neuromodulation and restoration of function as with other neurological subspecialties. Preliminary research supports the value of intrathecal baclofen pump and functional electrical stimulation in improving spasticity and motor function in MS patients. Deep brain stimulation can improve MS-related tremor and trigeminal neuralgia. Spinal cord stimulation has been shown to be effective against MS-related pain and bladder dysfunction. Bladder overactivity also responds to sacral neuromodulation and posterior tibial nerve stimulation. Despite limited data in MS, transcranial magnetic stimulation and brain-computer interface are promising neuromodulatory techniques for symptom mitigation and neurorehabilitation of MS patients. In this review, we provide an overview of the available neuromodulatory techniques and the evidence for their use in MS.

Persons With Chronic Spinal Cord Injuries in the Emergency Department: a Review of a Unique Population

BACKGROUND

Persons with spinal cord injuries (SCIs) are frequent utilizers of emergency medical services but are a poorly understood and medically complex population. As the treatment of acute spinal cord injuries improves, there is a growing population of patients suffering from the chronic neurological deficits and altered homeostasis resulting from those injuries.

OBJECTIVES

We sought to highlight the unique diagnostic challenges of treating persons with SCIs and to review ailments uncommon in the general population but often encountered in this population.

DISCUSSION

Spinal cord anatomy is briefly reviewed and commonly used nomenclature and grading scales are defined. An organ by organ review is offered detailing unique clinical issues that pertain to those systems. Practice pearls and pitfall are elucidated when relevant. Psychiatric complications of this disease entity are also discussed.

CONCLUSION

A SCI is a devastating but increasingly survivable event. The long-term care of persons with SCIs is challenging because of the unique pathologies encountered in this population and the disruption of normal and expected physiological responses to common ailments. This review will facilitate a better understanding of the emergency care needs of this unique patient population.

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.

Staged pallidotomy: MRI and clinical follow-up in status dystonicus

PURPOSE

We report on a patient affected by Status Distonicus who was treated with Deep Brain Stimulation electrodes implanted in the Globus Pallidus internus (Gpi) and used for serial radiofrequency lesions.

MATERIALS AND METHODS

The evolution of radiofrequency lesions was monitored by post-operative and late Magnetic Resonance Imaging (MRI). After the first lesion the patient did improve, though not in a significant fashion. Therefore, three further radiofrequency lesions were delivered 2, 4 and 6 days respectively after surgery with subsequent improvement of dystonic movements.

RESULTS

MRI scans performed at 8 days, 3 months, and 6 months after surgery showed a diffuse T2-hyperintense and T1-hypointense GPi signal alteration which progressively decreased over time.

CONCLUSION

We confirm that the possibility to stage pallidotomies over time using a couple of new contacts is a safe and efficacious procedure in treating SD patients where the lesions themselves are limited by the appearance of side effects, or in patients showing a poor response to a single lesion. As far as we know, this is the first description of MRI evolution and monitoring of a staged pallidotomy.

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.

Baclofen Pumps: Uses and Complications

Intrathecal baclofen therapy, given via an implanted pump in the abdominal wall either as a continuous infusion or bolus dosing, has been used for more than 25 years to treat the spasticity and dystonia associated with various brain and spinal cord conditions. Pediatric clinicians occasionally encounter baclofen pumps, and in the pediatric setting, significant morbidity can arise from their use. This article presents the background, mechanism of action, uses, and complications of intrathecal baclofen therapy and discusses various management strategies should complications occur.

Neuroleptic malignant syndrome: an easily overlooked neurologic emergency

Neuroleptic malignant syndrome is an unpredictable iatrogenic neurologic emergency condition, mainly arising as an idiosyncratic reaction to antipsychotic agent use. It is characterized by distinctive clinical features including a change in mental status, generalized rigidity, hyperpyrexia, and dysautonomia. It can be lethal if not diagnosed and treated properly. Mortality and morbidity attributed to this syndrome have recently declined markedly due to greater awareness, earlier diagnosis, and intensive care intervention. In most cases, the syndrome occurs as a result of a rapid increase in a dose of neuroleptic, especially one of the long-acting ones. Pathophysiology behind this syndrome is attributed to a dopamine receptor blockade inside the neurons rendered by the offending drug and excessive calcium release from the sarcoplasmic reticulum of skeletal myocytes. Laboratory tests, although not diagnostic, may assist in assessing the severity of the syndrome and also the consequent complications. The syndrome has been described in all age groups and occurs more in males than in females. Genetics appears to be central regarding the etiology of the syndrome. Stopping the use of the offending agent, cold intravenous fluids, and removal of the causative agent and its possible active metabolites is the cornerstone of treatment. Periodic observation of psychotic patients recently started on antipsychotic medications, especially those being treated with depot preparations, may aid to an early diagnosis of the syndrome and lead to early treatment.

Successful treatment of severe baclofen toxicosis initially refractory to conventional treatment

After ingesting a dose of baclofen thought to be lethal, a patient with severe neurologic signs was successfully managed despite initially being refractory to treatment. Patients with persistent neurologic abnormalities may still have an excellent prognosis despite lack of initial response. Additionally, we present a potential case of benzodiazepine withdrawal.

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.