1315 - Subcutaneous botulinum toxin for neuropathic pain due to critical illness polyneuropathy

Friday, February 20, 2026

5:00 PM - 6:30 PM AST

Presenting Author(s)

PP

Paras Patel, MD

Resident Physician
Medical College of Wisconsin
Milwaukee, Wisconsin, United States

Co-Author(s)

LS

Lauren E. Shuda, MD

Assistant Professor
Medical College of Wisconsin
Wauwatosa, Wisconsin, United States

Submitter(s)

PP

Paras Patel, MD

Medical College of Wisconsin
Milwaukee, Wisconsin, United States

Case Diagnosis: Critical Illness Polyneuropathy

Case Description: Patient is a 28-year-old female who had a complex three-month hospitalization due to disseminated blastomycoses complicated by septic shock, anoxic encephalopathy, multiorgan failure, and bilateral lower extremity weakness with right foot drop. Inpatient EMG was most consistent with critical illness polyneuropathy with possible additional right lumbosacral plexopathy explaining the asymmetric weakness. She progressed well and was admitted to acute inpatient rehabilitation before being seen for outpatient PM&R follow-up. At this time, she noted left dorsal foot numbness and burning pain that was getting worse. We injected 155 units (1:1 dilution) of botulinum toxin type A subcutaneously, creating wheels in a grid like pattern over the dorsal foot. At three-month follow-up, she reported complete resolution of neuropathic burning pain and numbness in her left foot.

Discussions: Subcutaneous botulinum toxin is a well-studied modality for the treatment of neuropathic pain relating to peripheral polyneuropathy. Proposed mechanisms include inhibition of nerve terminal glutamate, substance P, and calcitonin gene-related peptide; modulation of central sensitization through retrograde transport to the dorsal root ganglia and spinal cord; and suppression of pro-inflammatory cytokines. While most studies focus on diabetic peripheral polyneuropathy, post-herpetic neuralgia, or trigeminal neuralgia, there are no reported cases of its use for neuropathic pain due to critical illness polyneuropathy.

Conclusions: We present a case with complete resolution of neuropathic pain due to critical illness polyneuropathy three months after subcutaneous botulinum toxin injection. Botulinum toxin is well established in the use of spasticity management, but there are opportunities to study its utility in treating various etiologies of neuropathic pain.