Lumbosacral plexus MR tractography: A novel diagnostic tool for extraspinal sciatica and pudendal neuralgia?

Nucelio Lemos; Homero J F Melo; Corey Sermer; Gustavo Fernandes; Augusta Ribeiro; Geovanne Nascimento; Zhong Cheng Luo; Manoel J B C Girão; Suzan Menasce Goldman

doi:10.1016/j.mri.2021.08.003

Lumbosacral plexus MR tractography: A novel diagnostic tool for extraspinal sciatica and pudendal neuralgia?

Magn Reson Imaging. 2021 Nov:83:107-113. doi: 10.1016/j.mri.2021.08.003. Epub 2021 Aug 14.

Authors

Nucelio Lemos¹, Homero J F Melo², Corey Sermer³, Gustavo Fernandes⁴, Augusta Ribeiro⁵, Geovanne Nascimento⁶, Zhong Cheng Luo⁷, Manoel J B C Girão⁸, Suzan Menasce Goldman⁹

Affiliations

¹ Department of Obstetrics and Gynecology of Women's College Hospital and Mount Sinai Hospital, University of Toronto, Toronto, ON, Canada; Department of Gynecology, Escola Paulista de Medicina, Federal University of São Paulo, Brazil; Department of Neuropelveology and Advanced Pelvic Surgery, Increasing - Institute of Care and Rehabilitation in Neuropelveology and Gynecology, São Paulo, Brazil. Electronic address: nucelio.lemos@utoronto.ca.
² Instituto de Educação Superior IMEB (IMEB-IES), Brasilia, Brazil.
³ Department of Obstetrics and Gynecology of Women's College Hospital and Mount Sinai Hospital, University of Toronto, Toronto, ON, Canada.
⁴ Department of Gynecology, Escola Paulista de Medicina, Federal University of São Paulo, Brazil; Department of Neuropelveology and Advanced Pelvic Surgery, Increasing - Institute of Care and Rehabilitation in Neuropelveology and Gynecology, São Paulo, Brazil; Department of Obstetrics and Gynecology, Santa Casa School of Medical Sciences, São Paulo, Brazil.
⁵ Department of Gynecology, Escola Paulista de Medicina, Federal University of São Paulo, Brazil; Department of Neuropelveology and Advanced Pelvic Surgery, Increasing - Institute of Care and Rehabilitation in Neuropelveology and Gynecology, São Paulo, Brazil.
⁶ Department of Magnetic Resonance Imaging, CURA- Centro de Ultrassonografia e Radiologia Aplicada, São Paulo, SP, Brazil.
⁷ Lunenfeld-Tanenbaum Research Institute, Department of Obstetrics and Gynecology, Mount Sinai Hospital, University of Toronto, Toronto, Canada.
⁸ Department of Gynecology, Escola Paulista de Medicina, Federal University of São Paulo, Brazil.
⁹ Department of Magnetic Resonance Imaging, CURA- Centro de Ultrassonografia e Radiologia Aplicada, São Paulo, SP, Brazil; Department of Radiology, Escola Paulista de Medicina, Federal University of São Paulo, Brazil.

PMID: 34400289
DOI: 10.1016/j.mri.2021.08.003

Abstract

Background: Diagnosing extraspinal sciatica and pudendal neuralgia remains a clinical challenge. MRI and MR Neurography (MRN) are currently the standard techniques used to support the diagnosis of extraspinal lumbosacral plexus entrapments; however, for the intrapelvic portions of the lumbosacral plexus their accuracy is still limited. MR Tractography (MRT) feasibility to image the lumbosacral plexus has been demosntrated, but its clinical applications have yet to be determined.

Purpose: To correlate MRT with intraoperative findings in patients undergoing laparoscopic treatment of intrapelvic entrapments of the lumbosacral plexus and compare its accuracy with Neuropelveological clinical assessment and MRN.

Materials and methods: This is a retrospective analysis of MRT reconstructions of diffusion tensor imaging (DTI) sequences acquired for the MRN collected from a cohort of 13 patients undergoing laparoscopic detrapment of the lumbosacral plexus. The primary outcome of this study was the correlation of MRT reconstruction with intraoperative findings. Secondary outcomes included the correlation of MRN, preoperative Neuropelveological clinical diagnoses and the diffusion-weighted imaging (DWI) fractional anisotropy (FA) and Apparent Diffusion Coefficient (ADC) in patients undergoing pelvic MRI and MRN for the investigation of intrapelvic nerve entrapments.

Results: MRT correlated with intraoperative findings in 11 of 13 patients (85%). Neuropelveological clinical assessment was able to accurately diagnose a pelvic nerve entrapment in 12/13 patients (92%) and MRN agreed with surgical findings in only 2/13 (15%) patients. MRT was significantly superior to MRN (p < 0.001). FA and ADC did not correlate with the identification of a nerve entrapment, likely due to limitations regarding the placement of the seedpoints.

Conclusions: This initial, retrospective analysis, suggests that MRT is superior to MRN at diagnosing intrapelvic entrapments of the lumbosacral plexus. A prospective, double-blinded study is underway to validate this data, but these initial findings show great potential for MRT as a diagnostic tool for extraspinal sciatica and pudendal neuralgia. Clinical Trials Registry: U1111-1261-4910 (REBEC - Brazilian Registry for Clinical Trials).

Keywords: Extraspinal sciatica; Lumbosacral plexus; MRI; Peripheral nerve entrapment; Pudendal neuralgia; Tractography.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Diffusion Tensor Imaging
Humans
Lumbosacral Plexus / diagnostic imaging
Magnetic Resonance Imaging
Prospective Studies
Pudendal Neuralgia*
Retrospective Studies
Sciatica* / diagnostic imaging

Associated data

ReBec/U1111–1261-4910