UTILITY OF PHYSICAL ASSESSMENT IN INTRATHECAL BACLOFEN SCREENING TRIALS

R. Kuroiwa^1,2, K. Shibuya², K. Sakamoto¹, M. Nemoto¹, A. Murata¹, Y. Higuchi³, S. Kuwabara²

¹Chiba University Hospital, Division of Rehabilitation Medicine, Chiba, Japan, ²Chiba University Graduate School of Medicine, Neurology, Chiba, Japan, ³Chiba University Graduate School of Medicine, Neurological Surgery, Chiba, Japan

Background: Intrathecal baclofen (ITB) therapy is well documented as an effective treatment option for severe spasticity. Generally, prior to ITB device implantation, the response to ITB is usually tested during an ITB screening trial to explore efficacy and safety, identify appropriate candidates for ITB device surgery. Many centers offering ITB therapy organize a multidisciplinary team composed of neurologists, neurosurgeons, and physiotherapists to improve patient selection and outcomes.

Purpose: To identify appropriate physical examinations of ITB screening trials in candidates for ITB therapy.

Methods: This retrospective open-label study was undertaken at a university hospital investigating admissions between January 2015 and December 2021. We included patients with spasticity who underwent an ITB screening trial. All had suffered from paraplegia for at least 12 months. A baseline assessment was performed before administering the test dose and periodically throughout the day. On day 1 of screening, 12.5 μg baclofen was administered intrathecally and the patient's physical function was measured 4 hours later. Then for each subsequent day, the doses of baclofen were increased up to 100 μg, followed by measuring physical function.
Physical assessment, performed by a physiotherapist, included targeted neuromuscular tests (modified Ashworth scale, reflexes, clonus, active-range of motion, manual muscle test) and balance and walk tests (Berg balance scale, Timed Up and Go test, 10-meter walk test). For neuromuscular tests, scores from both lower extremities were averaged. To compare physical assessment tests between before ITB screening and during ITB screening (when a specific baclofen dose was most effective with the best clinical response), the Wilcoxon signed-rank test for paired observations was used.

Results: Twenty-two patients (17 males, 5 females; mean age, 54.9 years) underwent trial treatment with ITB. Their diagnoses included hereditary spastic paraplegia and myelitis. Among the physical assessment tests, there were significant differences between before and during ITB for the modified Ashworth scale, tendon reflexes, Timed Up and Go test, and 10-meter walk test, whereas ankle clonus, active range of motion, and manual muscle test showed no significant difference. The total score of the Berg balance scale showed no significant difference, whereas only the item of "placing alternate foot on stool" was significant differences.

Conclusions: Physical assessment tests, useful in the ITB screening trial, were modified Ashworth scale, tendon reflexes, Timed Up and Go test, 10-meter walk test, and the item of "placing alternate foot on stool" in the Berg balance scale.

Implications: The findings suggest that physical assessment may be useful as a best practice strategy for ITB screening trials. Therefore, physiotherapists should consider brushing up on their assessment content as experts in physical assessment to expand the field of the physiotherapy profession.

Funding acknowledgements: No direct funding was received for this study.

Keywords:
Intrathecal baclofen
Physical assessment
Spasticity

Topics:
Neurology

Did this work require ethics approval? Yes

Institution: Chiba University Hospital

Committee: The Chiba University Hospital Ethics Committee

Ethics number: 5021