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

Outcomes of intrathecal baclofen therapy in patients with cerebral palsy and acquired brain injury

Intrathecal baclofen (ITB) has been known to reduce spasticity which did not respond to oral medications and botulinum toxin treatment. However, few results have been reported comparing the effects of ITB therapy in patients with cerebral palsy (CP) and acquired brain injury. This study aimed to investigate beneficial and adverse effects of ITB bolus injection and pump therapy in patients with CP and to compare outcomes to patients with acquired brain injury such as traumatic brain injury and hypoxic brain injury. ITB test trials were performed in 37 patients (19 CP and 18 acquired brain injury). Based on ambulatory function, CP patients were divided into 2 groups: 11 patients with nonambulatory CP and 8 patients with ambulatory CP. Change of spasticity was evaluated using the Modified Ashworth Scale. Additional positive or negative effects were also evaluated after ITB bolus injection. In patients who received ITB pump implantation, outcomes of spasticity, subjective satisfaction and adverse events were evaluated until 12 months post-treatment. After ITB bolus injection, 32 patients (86.5%) (CP 84.2% versus acquired brain injury 88.9%) showed a positive response of reducing spasticity. However, 8 patients with CP had negative adverse effects. Particularly, 3 ambulatory CP patients showed standing impairment and 1 ambulatory CP patient showed impaired gait pattern such as foot drop because of excessive reduction of lower extremity muscle tone. Ambulatory CP patients received ITB pump implantation less than patients with acquired brain injury after ITB test trials (P = .003 by a chi-squared test). After the pump implantation, spasticity was significantly reduced within 1 month and the effect maintained for 12 months. Seventeen patients or their caregivers (73.9%) were very satisfied, whereas 5 patients (21.7%) suffered from adverse events showed no subjective satisfaction. In conclusion, ITB therapy was effective in reducing spasticity in patients with CP and acquired brain injury. Before ITB pump implantation, it seems necessary to perform the ITB bolus injection to verify beneficial effects and adverse effects especially in ambulatory CP.

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

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

Intrathecal baclofen therapy for spasticity of cerebral origin--does the position of the intrathecal catheter matter?

OBJECTIVE

To assess the correlation between the position of the intrathecal baclofen therapy catheter with the clinical outcome and response to the spasticity.

METHODS AND RESULTS

A prospective cohort study was done by reviewing the paediatric group of patients with spasticity of cerebral origin who had insertion of a programmable baclofen pump for intrathecal administration in the last 10 years (August 1998 to September 2007). A total of 190 procedures were carried out in 166 patients, under a single paediatric neurosurgeon, with an age range of 18 months-16 years (mean 8.75 years) with follow up of 1-10 years (mean 5 years). The routine post-operative X-rays, which were done as per protocol, were reviewed, and the position of the intrathecal catheter tip was documented in relation to the vertebral bodies. The maintenance intrathecal baclofen dose was 25 microgms to 1,000 microgms (mean 255.8 microgms) based on the clinical response to spasticity. Statistical analysis was carried out to assess the correlation of the position of the tip of the intrathecal catheter with the outcome in spasticity based on GMFCS (Gross Motor Function Classification System) and Ashworth score.

CONCLUSION

In our series, there was no statistically significant correlation between the position of the intrathecal catheter and the clinical response to the spasticity.

Satisfaction of individuals treated long-term with continuous infusion of intrathecal baclofen by implanted programmable pump

PURPOSE

To investigate the perspective of the individual receiving intrathecal baclofen (ITB) or his/her caregiver concerning its effects and to describe characteristics of those that were satisfied or not satisfied.

METHODS

After IRB approval, potential subjects were identified who had undergone ITB pump implantation at least 1 year prior to the study. One hundred subjects/caregivers were interviewed by phone. Interview consisted of a scripted questionnaire to obtain subject/caregiver opinions about changes in function and caregiver assistance, as well as satisfaction with ITB. Medical records were reviewed to collect information including diagnosis, ITB related surgeries and medications.

RESULTS

Subjects ranged in age from 5-42 years and 88 had a diagnosis of cerebral palsy. Improvement was noted in the following areas: positioning 69%, transfers 58%, dressing 69% and toileting/hygiene 51%. Fifty-four per cent reported reduction in startle movements. Sleep was improved in 43% and comfort in 53%. Twenty-two subjects experienced 32 events related to the ITB hardware or surgery. Only 12% indicated they would not choose to undergo the procedure again.

DISCUSSION

Generally, subjects and their caregivers were satisfied with the results after ITB pump implantation. A majority reported improvements in positioning, transfers, dressing, toileting/hygiene and comfort.

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.

Motor neuron inhibition-based gene therapy for spasticity

Spasticity is a condition resulting from excess motor neuron excitation, leading to involuntary muscle contraction in response to increased velocity of movement, for which there is currently no cure. Existing symptomatic therapies face a variety of limitations. The extent of relief that can be delivered by ablative techniques such as rhizotomy is limited by the potential for sensory denervation. Pharmacological approaches, including intrathecal baclofen, can be undermined by tolerance. One potential new approach to the treatment of spasticity is the control of neuromuscular overactivity through the delivery of genes capable of inducing synaptic inhibition. A variety of experiments in cell culture and animal models have demonstrated the ability of neural gene transfer to inhibit neuronal activity and suppress transmission. Similarly, enthusiasm for the application of gene therapy to neurodegenerative diseases of motor neurons has led to the development of a variety of strategies for motor neuron gene delivery. In this review, we discuss the limitations of existing spasticity therapies, the feasibility of motor neuron inhibition as a gene-based treatment for spasticity, potential inhibitory transgene candidates, strategies for control of transgene expression, and applicable motor neuron gene targeting strategies. Finally, we discuss future directions and the potential for gene-based motor neuron inhibition in therapeutic clinical trials to serve as an effective treatment modality for spasticity, either in conjunction with or as a replacement for presently available therapies.

Chronic Pain and Obstetric Management of a Patient with Tuberous Sclerosis

Chronic nonmalignant pain is very disabling and carries a heavy financial strain on the individual and society as a whole. This case describes a woman with tuberous sclerosis, in her fourth pregnancy. Approximately 18 months prior to pregnancy, intractable left loin pain, thought to be secondary to hemorrhage within a tuberous lesion in the left kidney, had led to the siteing of an intrathecal morphine pump. The risks of system failure (dislodgement, dislocation), escalating dosage, infection, use in labor, and neonatal opioid withdrawal are all explored and discussed. While data are limited, with increasing use of intrathecal opioids for nonmalignant pain, such patients may be seen more regularly in obstetric clinics. With a multidisciplinary team approach, risks can be minimized and outcome for mother and baby optimized.

Neurologische Komplikationen und Wirkverlust unter intrathekaler Schmerztherapie

In a new guideline issued by the German Association for the Study of Pain, intrathecal opioid therapy is described as proven to be effective with relatively few side effects. We reviewed this statement by analysis of the available literature and critical evaluation of the clinical course in a few of our own patients (n=3). In these cases (as well as in a further eight patients), explantation and a switch to oral opioids led to distinctly better alleviation of pain and abatement of the unwanted effects. The problems we discuss do not appear to be rare instances, but by all means complications that are frequently described. The long-term efficacy of intrathecal opioids has not been adequately verified; moreover, their potency is not high. The frequency of undesired events is comparable to that of oral opioid medication, but serious neurological complications are possible. To avoid dose escalations and to recognize neurological complications in time, diligent monitoring by the surgeon or an experienced pain center is essential.

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

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

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

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