23rd Annual Pain Medicine Meeting 2024

Early Consideration for Intrathecal Baclofen Treatment for Refractory Stiff Person Syndrome: A Case Report

Introduction

Stiff Person Syndrome (SPS)

A rare autoimmune neurological disorder of the central nervous system that is characterized by painful rigidity and spasticity, commonly affecting the truncal and proximal limb muscles.¹
A multidisciplinary approach to care with pain management, physical therapy, and occupational therapy is recommended (Figure).²
Symptomatic treatment consists of GABAergic medications, baclofen, and disease-modifying therapy of intravenous immunoglobulin (IVIG).¹
If refractory to above, Intrathecal baclofen (ITB) has shown to significantly reduce spasticity in SPS patients.^3,4

Purpose

The overall aim of our study was to bring awareness to the complex pain management in patients with Stiff Person Syndrome and present a case of significant improvement in refractory spasticity in SPS following ITB trial.

Case Description

Chief Complaint: 38-year-old male diagnosed with SPS with positive anti-glutamic acid decarboxylase antibodies (anti-GAD) in 2021 presents to chronic pain clinic with severe muscle spasticity, skin hypersensitivity, and hyperacusis.
Prior Treatments: monotherapy with diazepam, combined pharmacotherapies, immunotherapy with IVIG and botulinum toxin injections (Table).
Intervention:ITB trial with administration of 50 mcg baclofen into intrathecal space of L2-3.
Result: Reported reduction in frequency of spasms and severity of pain for three hours after administration.
Further Plan: deemed an adequate candidate for and currently pending ITB pump implantation.

Discussion

SPS is a debilitating autoimmune neurological disorder affecting one’s functionality and quality of life.
If oral antispasmodics and immunotherapy fails, ITB has shown to be a successful adjunct for SPS with intractable muscle spasms.^3,4
Following implantation, patients have reported improved functionality including ambulation without assisted devices; decreased pain and severity of spastic hypertonia.^4,5
Initial ITB dosing ranging from 32 to 120 mcg/day and maintenance dosing from 48 to 320 mcg/day have been shown to be successful.⁵
Advantages of ITB:⁵
Less systemic side effects compared to oral therapy
Ability to titrate to therapeutic cerebrospinal fluid levels
Maximized efficacy with smaller drug doses
Common potential post-procedural risks include infection, hardware malfunction, pump failure, and catheter leakage leading to acute baclofen withdrawal.⁶

Conclusion

Further research is needed to establish standard dosing protocol for ITB trial and post-implantation doses.
Treating chronic pain from SPS can be complex; however, SPS refractory to multiple oral medications should prompt early consideration for ITB trial and implantation.

References

Ortiz JF, Ghani MR, Morillo Cox Á, et al. Stiff-Person Syndrome: A Treatment Update and New Directions. Cureus. 2020;12(12):e11995.
Nolan, J.D. and Nicholas, J.A. (2020). Stiff-person syndrome: Treatment consists of immunomodulatory therapies and symptom management. Practical Neurology.
Newton JC, Harned ME, Sloan PA, Salles SS. Trialing of intrathecal baclofen therapy for refractory stiff-person syndrome. Reg Anesth Pain Med. 2013;38(3):248-250.
Zhang B, Lau R, van Why D, Saulino M. Effectiveness of Intrathecal Baclofen for Intractable Stiffperson Syndrome: a Case Report. J Rehabil Med Clin Commun. 2021;4:1000052.
Abbatemarco JR, Willis MA, Wilson RG, Nagel SJ, Machado AG, Bethoux FA. Case Series: Intrathecal Baclofen Therapy in Stiff-Person Syndrome. Neuromodulation J Int Neuromodulation Soc. 2018;21(7):655-659.
Bardutzky J, Tronnier V, Schwab S, Meinck HM. Intrathecal baclofen for stiff-person syndrome: life-threatening intermittent catheter leakage. Neurology. 2003;60(12):1976-1978.

EARLY CONSIDERATION FOR INTRATHECAL BACLOFEN TREATMENT FOR REFRACTORY STIFF PERSON SYNDROME: A CASE REPORT