Segmental infralesional pathological spontaneous activity in subacute traumatic spinal cord injury.

INTRODUCTION/AIMS: There is a dearth of knowledge regarding the status of infralesional lower motor neurons (LMNs) in individuals with traumatic cervical spinal cord injury (SCI), yet there is a growing need to understand how the spinal lesion impacts LMNs caudal to the lesion epicenter, especially in the context of nerve transfer surgery to restore several key upper limb functions. Our objective was to determine the frequency of pathological spontaneous activity (PSA) at, and below, the level of spinal injury, to gain an understanding of LMN health below the spinal lesion. METHODS: Ninety-one limbs in 57 individuals (53 males, mean age = 44.4 ± 16.9 years, mean duration from injury = 3.4 ± 1.4 months, 32 with motor complete injuries), were analyzed. Analysis was stratified by injury level as (1) C4 and above, (2) C5, and (3) C6-7. Needle electromyography was performed on representative muscles innervated by the C5-6, C6-7, C7-8, and C8-T1 nerve roots. PSA was dichotomized as present or absent. Data were pooled for the most caudal infralesional segment (C8-T1). RESULTS: A high frequency of PSA was seen in all infralesional segments. The pooled frequency of PSA for all injury levels at C8-T1 was 68.7% of the limbs tested. There was also evidence of PSA at the rostral border of the neurological level of injury, with 58.3% of C5-6 muscles in those with C5-level injuries. DISCUSSION: These data support a high prevalence of infralesional LMN abnormalities following SCI, which has implications to nerve transfer candidacy, timing of the intervention, and donor nerve options.

Early adjunct treatment with topical lidocaine results in improved pain and function in a patient with complex regional pain syndrome.

Complex regional pain syndrome (CRPS) is a pain disorder characterized by sensory, motor, trophic and autonomic dysfunction. The hallmark of the disorder is pain out of proportion of the inciting event. CRPS is difficult for clinicians to manage as there is no gold standard for diagnosis or treatment. Patients with CRPS are at risk of developing contractures, tissue atrophy, joint dislocation and severe chronic pain. While CRPS is thought to be due to peripheral and central nervous system dysfunction, there is limited understanding of the pathophysiology of CRPS. The proposed mechanisms are multifactorial and consequently, so are the proposed treatments. These treatments can be invasive, such as intrathecal drug delivery or sympathectomy, which have poor evidence for efficacy. Thus, highlighting the need for a safe, effective, and early intervention. We present a case of topical 5% lidocaine ointment as a non-invasive, inexpensive and effective adjunct treatment in the management of pain in a spinal cord injured patient presenting with early CRPS. The clinically important effect of topical lidocaine for reducing severe allodynia allowed the patient to participate in rehabilitation strategies to further manage the debilitating consequences of her CRPS, including decreased range of motion (ROM) and function. The immediate pain relief from topical lidocaine allowed the patient to tolerate physical therapy sessions directed at her CRPS. A successful outcome was measured subjectively and objectively by our patient's reduction in symptoms and improvement in ROM and function, respectively. This case study provides preliminary support for improved pain and functional outcome with early adjunct treatment of CRPS with topical lidocaine.