Does Every Patient Require an Intrathecal Baclofen Trial Before Pump Placement?

Knee Muscle Stretch Reflex Responses After an Intrathecal Baclofen Bolus in Neurological Patients With Moderate-to-Severe Hypertonia

OBJECTIVES

To examine the prevalence, onset threshold, and response magnitude of stretch reflex response (SRR) in the knee extensors and flexors before and after an intrathecal baclofen (ITB) bolus injection in patients with moderate-to-severe hypertonia.

MATERIALS AND METHODS

SRRs were elicited by reciprocal passive knee extension/flexion movements at preset angular velocities of 5, 60, 120, 180, 240, and 300°/s using an isokinetic dynamometer and recorded with surface electromyographic (EMG) electrodes placed over the knee extensors and flexors in 53 neurologic patients before and at 2.5 and 5 hours after an ITB injection via lumbar puncture. Outcome measures included the number of patients with presence/absence of SRRs, the number of SRRs per session, SRR onset threshold angle and velocity, and response magnitudes (peak EMG and area under the EMG curve) for each muscle. Pre-post comparisons were completed using the Fisher's exact and Wilcoxon signed rank tests.

RESULTS

For both knee extensors and flexors, the proportion of patients with present SRRs (p < 0.0001) and the number of SRRs per session (p ≤ 0.027) decreased from pre- to post-ITB. The threshold velocity significantly increased post-injection in both muscles (p ≤ 0.001) without significant changes in the threshold angle. The response magnitudes significantly decreased in the knee extensors (p ≤ 0.016) but not the knee flexors after the injection.

CONCLUSIONS

The prevalence and threshold velocity of SRR emerged as the most robust and practical parameters for assessing hyperreflexia during ITB bolus trial that can complement clinical assessment of muscle hypertonia.

Intrathecal Therapies

Intrathecal baclofen therapy is a well-established technique for spasticity management. This article briefly reviews the pharmacology of intrathecal baclofen as well as customary approach for utilization of this targeted drug delivery concept. Following these descriptions, four unusual presentations will be described, including the need for initial trialing, patient-directed boluses during chronic intrathecal baclofen therapy, use of medications other than baclofen for intrathecal therapy in spastic patients, and intraventricular baclofen delivery. These hypothetical cases are provided in an effort to expand the use of targeted drug delivery to larger population of spastic patients.

Title: Quantifying the change of spasticity after intrathecal baclofen administration: A descriptive retrospective analysis

OBJECTIVES

Exploratory research quantifying the change of spasticity among patients who underwent baclofen intrathecal drug delivery system (IDDS) implantation.

PATIENTS AND METHODS

88 patients with a baclofen IDDS were identified. Patient characteristics, spasticity scores pre/post intrathecal baclofen test dose, and IDDS perioperative implantation records were collected. The primary outcome was to quantify the extent to which there was a change in Modified Ashworth Scores (MAS) pre/post-intrathecal baclofen test dose administration. Secondary outcomes included the prevalence of perioperative IDDS implantation complications.

RESULTS

The mean age at IDDS implant was 44.2 years (range, 19-71), and 62.5% were male. 45.5% had spasticity of spinal cord origin, 9% of cerebral origin, and 45.5% of other upper motor neuron dysfunction. Reduction of MAS in the spinal cord origin group was 2.6 (mean, 3.5 to 0.9), cerebral origin group was 2.9 (mean, 3.3 to 0.4), and other origin group was 2.5 (mean, 3.6 to 1.1). In all patients, post dural puncture headache was the most commonly reported complication at 22.7%.

CONCLUSION

This report offers novel findings documenting a quantifiable change of at least two points on the MAS before and after intrathecal baclofen test dose as statistically significant and could prove to be useful information to enhance the decision making process to proceed with intrathecal baclofen beyond assessment of functional abilities.

Optimizing the Management of Spasticity in People With Spinal Cord Damage: A Clinical Care Pathway for Assessment and Treatment Decision Making From the Ability Network, an International Initiative

The recognition, evaluation, and management of disabling spasticity in persons with spinal cord damage (SCD) is a challenge for health care professionals, institutions, health systems, and patients. To guide the assessment and management of disabling spasticity in individuals with SCD, the Ability Network, an international panel of clinical experts, developed a clinical care pathway. The aim of this pathway is to facilitate treatment decisions that take into account the effect of disabling spasticity on health status, individual preferences and treatment goals, tolerance for adverse events, and burden on caregivers. The pathway emphasizes a patient-centered, individualized approach and the need for interdisciplinary coordination of care, patient involvement in goal setting, and the use of assessment and outcome measures that lend themselves to practical application in the clinic. The clinical care pathway is intended for use by health care professionals who provide care for persons with SCD and disabling spasticity in various settings. Barriers to optimal spasticity management in these people are also discussed. There is an urgent need for the clinical community to clarify and overcome barriers (knowledge-based, organizational, health system) to optimizing the management of spasticity in people with SCD.