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.

Transdermal Delivery of Baclofen Using Iontophoresis and Microneedles

Baclofen, a GABA_b agonist, is used in the treatment of multiple sclerosis, a neurodegenerative disease. Currently available dosage forms to deliver baclofen are through the oral and the intrathecal routes. The disadvantage of oral baclofen is that it requires administering the drug multiple times a day, owing to baclofen's short half-life. On the other hand, intrathecal baclofen pumps are invasive and cannot be an alternative to oral baclofen. Hence, there is a need to develop a dosage form that can deliver baclofen non-invasively and for an extended period at a steady rate, increasing the dosing interval. A transdermal baclofen delivery system might be the solution to this problem. Hence, this research focuses on evaluating microneedles, iontophoresis, and a combination of microneedles-iontophoresis as transdermal delivery enhancement strategies for baclofen. In vitro permeation studies were conducted on dermatomed porcine ear skin using vertical Franz diffusion cells to evaluate transdermal baclofen delivery. Anodal iontophoresis was applied at a current density of 0.5 mA/cm², and transdermal delivery was assessed from pH 4.5 (45.51±0.76 μg/cm²) and pH 7.4 (68.84±10.13 μg/cm²) baclofen solutions. Iontophoresis enhanced baclofen delivery but failed to reach target delivery. Maltose microneedles were used to create hydrophilic microchannels on the skin, and this technique enhanced baclofen delivery by 89-fold. Both microneedles (447.88±68.06 μg/cm²) and combination of microneedles - iontophoresis (428.56±84.33 μg/cm²) reached the target delivery range (222-1184 μg/cm²) for baclofen. The findings of this research suggest that skin could be a viable route for delivery of baclofen. Graphical Abstract.

Intrathecal Delivery of BDNF Into the Lumbar Cistern Re-Engages Locomotor Stepping After Spinal Cord Injury

Delivery of neurotrophins to the spinal injury site via cellular transplants or viral vectors administration has been shown to promote recovery of locomotion in the absence of locomotor training in adult spinalized animals. These delivery methods involved risks of secondary injury to the cord and do not allow for precise and controlled dosing making them unsuitable for clinical applications. The present study was aimed at evaluating the locomotor recovery efficacy and safety of the neurotrophin BDNF delivered intrathecally to the lumbar locomotor centers using an implantable and programmable infusion mini-pump. Results showed that BDNF treated spinal cats recovered weight-bearing plantar stepping at all velocities tested (0.3-0.8 m/s). Spinal cats treated with saline did not recover stepping ability, especially at higher velocities, and dragged their hind paws on the treadmill. Histological evaluation showed minimal catheter associated trauma and tissue inflammation, underlining that intrathecal delivery by an implantable/programmable pump is a safe and effective method for delivery of a controlled BDNF dosage; it poses minimal risks to the cord and is clinically translational.

Baclofen in the Therapeutic of Sequele of Traumatic Brain Injury: Spasticity

Traumatic brain injury (TBI) is an alteration in brain function, caused by an external force, which may be a hit on the skull, rapid acceleration or deceleration, penetration of an object, or shock waves from an explosion. Traumatic brain injury is a major cause of morbidity and mortality worldwide, with a high prevalence rate in pediatric patients, in which treatment options are still limited, not available at present neuroprotective drugs. Although the therapeutic management of these patients is varied and dependent on the severity of the injury, general techniques of drug types are handled, as well as physical and surgical. Baclofen is a muscle relaxant used to treat spasticity and improve mobility in patients with spinal cord injuries, relieving pain and muscle stiffness. Pharmacological support with baclofen is contradictory, because disruption of its oral administration may cause increased muscle tone syndrome and muscle spasm, prolonged seizures, hyperthermia, dysesthesia, hallucinations, or even multisystem organ failure. Combined treatments must consider the pathophysiology of broader alterations than only excitation/inhibition context, allowing the patient's reintegration with the greatest functionality.

Treatment of severe, disabling spasticity with continuous intrathecal baclofen therapy following acquired brain injury: the experience of a tertiary institution in Singapore

INTRODUCTION

Intrathecal baclofen (ITB) therapy is a proven, effective treatment for disabling cortical spasticity. We describe the first local series of five patients with acquired brain injury (ABI) who received ITB and were followed up for 63.8 months.

METHODS

A retrospective review of medical and rehabilitation records of patients who received ITB therapy was carried out. Data studied included baseline demographic and injury variables, implantation data, spasticity and function, ITB dosage over time and complications.

RESULTS

From 2006 to 2010, a total of five patients received ITB therapy via implanted pumps about 39.4 months after ABI. Four out of five patients experienced significant reductions in their lower limb spasticity scores and improvements in global function and dependency. One patient had minor adverse events associated with baclofen-related sedation. The mean ITB dose at one year was 182.7 ± 65.6 mcg/day.

CONCLUSION

Our preliminary study showed encouraging long-term outcomes and safety for ITB therapy after ABI-related intractable spasticity. Individual ITB responses over time were variable, with gender differences. The outcomes experienced by our centre were comparable to those in the general ABI population, supporting the efficacy of ITB therapy for chronic disabling spasticity.

Role of Catheter's Position for Final Results in Intrathecal Drug Delivery. Analysis Based on CSF Dynamics and Specific Drugs Profiles

Intrathecal drug delivery is an effective and safe option for the treatment of chronic pathology refractory to conventional pain therapies. Typical intrathecal administered drugs are opioids, baclofen, local anesthetics and adjuvant medications. Although knowledge about mechanisms of action of intrathecal drugs are every day more clear many doubt remain respect the correct location of intrathecal catheter in order to achieve the best therapeutic result. We analyze the factors that can affect drug distribution within the cerebrospinal fluid. Three categories of variables were identified: drug features, cerebrospinal fluid (CSF) dynamics and patients features. First category includes physicochemical properties and pharmacological features of intrathecal administered drugs with special attention to drug lipophilicity. In the second category, the variables in CSF flow, are considered that can modify the drug distribution within the CSF with special attention to the new theories of liquoral circulation. Last category try to explain inter-individual difference in baclofen response with difference that are specific for each patients such as the anatomical area to treat, patient posture or reaction to inflammatory stimulus. We conclude that a comprehensive evaluation of the patients, including imaging techniques to study the anatomy and physiology of intrathecal environment and CSF dynamics, could become essential in the future to the purpose of optimize the clinical outcome of intrathecal therapy.

Use of intrathecal baclofen therapy in ambulant children and adolescents with spasticity and dystonia of cerebral origin: a systematic review

AIM

Studies on the use of intrathecal baclofen (ITB) for ambulant adults with spasticity and/or dystonia of cerebral origin are scarce, and are even more limited for children and adolescents. This systematic review investigates the use of ITB to improve walking, transfer ability, and gross motor activities in ambulant children and adolescents with spasticity and/or dystonia of cerebral origin.

METHOD

Electronic databases (MEDLINE, CINAHL, PsycINFO, EMBASE, full Cochrane Library, and PEDro) were searched from the earliest date available until March 2011 using combined subject headings and free text if supported by the databases. Studies were included if they had examined individuals who: (1) received ITB therapy by any method (bolus injection, an external delivery system, or an implanted pump); (2) had spasticity and/or dystonia of cerebral origin; (3) were able to ambulate with or without a walking device, i.e. individuals with cerebral palsy (CP) who were in levels I to III of the Gross Motor Function Classification System or individuals with similar functional mobility if they did not have CP; and (4) were aged 18 years or under. Publications in English in peer-reviewed journals reporting any type of research design, except reviews and expert opinions, were included. Studies were excluded if participants had spasticity and/or dystonia of spinal origin and if baclofen was administered only orally. Studies that compared ITB with other interventions such as botulinum toxin were also excluded.

RESULTS

Two independent reviewers scored 16 studies against the guidelines for developing systematic reviews from the American Academy of Cerebral Palsy and Developmental Medicine (AACPDM).

INTERPRETATION

Fifteen studies were of levels IV or V evidence and only one of level II according to the evidence levels of the AACPDM guidelines, but all were of low quality. No study was found on the use of ITB in ambulant children or adolescents with dystonia of cerebral origin. Not all studies used objective outcome measures to assess the ambulation, transfer ability, and gross motor activities of the participants. A proportion of participants showed improvement in all these areas but adverse events were common. A proportion of participants compromised their ambulatory and transfer abilities after ITB. There was no evidence to support the clinical use of ITB in ambulant individuals with hypertonicity without further rigorous longitudinal studies.

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

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

A Clinical Study of Intrathecal Baclofen Using a Programmable Pump for Intractable Spasticity

OBJECTIVE

To determine the impact of intrathecal baclofen (ITB) therapy on outcomes of functional independence, pain, subjective improvement, performance, and standard measures of spasticity.

DESIGN

A noncomparative, multicenter, prospective cohort trial of patients with implanted pumps followed up over a 12-month period for the assessment of spasticity, pain, and function.

SETTING

Twenty-four European centers of neurology or rehabilitation familiar with implantable pump technique participated.

PARTICIPANTS

Patients with intractable spasticity (N=138) who responded positively to a trial dose of baclofen (n=133) and who began ITB therapy (n=129) were enrolled.

INTERVENTION

Implantation of a Medtronic SynchroMed Infusion System with the administration of ITB therapy.

MAIN OUTCOME MEASURES

Ashworth Scale assessment, Penn Spasm Frequency Scale scores, pain assessment, FIM instrument scores or WeeFIM scores for children, Canadian Occupational Performance Measure (COPM), and subjective ratings of overall relief were the tools administered.

RESULTS

Muscle tone, spasm scores, and pain intensity reductions were observed. Overall FIM scores increased significantly in cognitive and motor function. COPM scores for both performance and satisfaction also improved significantly. Patients reported increased relief from pain and spasticity, supported by physician reports. Forty-three percent of patients reported adverse events, mostly related to patients' underlying conditions (20%), the device implant surgery (10%), or complications with the catheter (9%).

CONCLUSIONS

ITB therapy using a programmable pump is clinically effective and well tolerated, despite a seemingly high level of adverse events, in patients with intractable spasticity of spinal or cerebral origin and may offer improvements in pain relief and function.