Surgeons, physiatrists and neurologists speaking“EDX and nerve surgery”: A paradigm shift for nerve injured patients

Sep 29, 2026

Surgeons’ ability to interpret electrodiagnostic (EDX) studies has strengthened patient selection and outcome prediction for nerve surgeries by clarifying how nerve injury is classified. EDX reflects axons that are present, lost, or demyelinated, but cannot directly measure chronic ischemia, so Sunderland Zero must be a clinical diagnosis suggested by normal EDX, reduced EMG recruitment, and no atrophy. Recovery early after surgery is needed to confirm it. The article expands nerve injury classification, introduces Sunderland Zero/ischemic neurapraxia, and proposes a Nerve Injury Calculator to estimate axonal loss, demyelination, and ischemic injury and to guide prognosis timing via three cases.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages18

Reading Time45 min

AccessFree to download

Introduction

Seddon and Sunderland’s original classiﬁcation system

Expanded classiﬁcation emphasizing Sunderland Zero or ischemic neurapraxia

Nerve Injury Calculator (NIC) and user-friendly tools

JPRAS Open 47 (2025) 3–20 Contents lists available at ScienceDirect JPRAS Open journal [homepage:](homepage: www.elsevier.com/locate/jpra)[ www.elsevier.com/locate/jpra](homepage: www.elsevier.com/locate/jpra) Original Article Surgeons, physiatrists and neurologists speaking“EDX and nerve surgery”: A paradigm shift for nerve injured patients Deng Pana,\#, Aneri U. Patel a,\#, J. Megan Patterson b, Anna Rose Johnsona, Travis Gordon a, Susan E. Mackinnona,∗ a Division of Plastic and Reconstructive Surgery, Department of Surgery, Washington University School of Medicine, 660 S. Euclid Ave, St. Louis, MO, USA b Department of Orthopedic Surgery, University of North Carolina, Chapel Hill, 102 Mason Farm Road, NC, USA a r t i c l e i n f o Article history: Received 14 October 2025 Accepted 2 November 2025 Available online 12 November 2025 Keywords: nerve surgery nerve injury classiﬁcation EDX studies Sunderland Zero nerve recovery a b s t r a c t Surgeons’ ability to interpret electrodiagnostic (EDX) studies has greatly enhanced patient selection and outcome for nerve surgeries as it has informed our understanding of the classiﬁcation of nerve injury. EDX measures axons present, lost, or demyelinated. It does not measure an area where axons experience chronic ischemia, making a Sunderland Zero nerve injury a clinical diagnosis that should be suspected when patients have normal EDX, decreased recruitment on electromyography (EMG), and no atrophy. Only observation of recovery in the earliest postoperative period would conﬁrm a Sunderland Zero. In this article, we present an expanded classiﬁcation of nerve injury, highlighting Sunderland Zero or ischemic neurapraxia, and provide a historical and pathophysiological overview of how it came to be recognized. We also offer a user-friendly classiﬁcation and an equation we call the Nerve Injury Calculator (NIC) that calculates the percent axonal loss, demyelinating loss, and ischemic axons to predict timing and quality of recovery. The clinical utility of the NIC is exempliﬁed with three cases. With the development and introduction of the NIC, there is ∗ Corresponding author. \# Deng Pan and Aneri U. Patel are co-ﬁrst authors and contributed equally to this work. [https://doi.org/10.1016/j.jpra.2025.11.004](https://doi.org/10.1016/j.jpra.2025.11.004) 2352-5878/Published by Elsevier Ltd on behalf of British Association of Plastic, Reconstructive and Aesthetic Surgeons. This isan open access article under the CC BY-NC-ND license ([http://creativecommons.org/licenses/by-nc-nd/4.0/](http://creativecommons.org/licenses/by-nc-nd/4.0/)) D. Pan, A. U. Patel, J.M. Patterson et al. JPRAS Open 47 (2025) 3–20 a paradigm shift amongst surgeons, physiatrists, and neurologists that allows us all to speak the same language of EDX and nerve surgery, enabling improved patient education, prediction of prognosis and timing of recovery, and eﬃcient follow up with respect to patients’ postoperative period. Published by Elsevier Ltd on behalf of British Association of Plastic, Reconstructive and Aesthetic Surgeons. This is an open access article under the CC BY-NC-ND license ([http://creativecommons.org/licenses/by-nc-nd/4.0/](http://creativecommons.org/licenses/by-nc-nd/4.0/)) Introduction Indications for nerve surgery expand as new innovations drive new techniques. Management strategies have progressed signiﬁcantly due to a combination of a new awareness of neural fascicular anatomy, basic science research, and clinical experience. By bringing axons closer to their targets nerve transfers have increased the likelihood of functional recovery as the most important factor inﬂuencing recovery has been identiﬁed as the time to reinnervation of the distal motor end plate and sensory receptors.1 However, appropriate patient selection remains critical for the success of all nerve surgeries. In recent years, there has been increased awareness on the importance of sur

FAQs

Why is EDX interpretation central to nerve surgery outcomes?

EDX interpretation helps surgeons select appropriate patients and better predict the degree and pattern of injury, recovery likelihood, and timing, which also supports choosing suitable surgical options and improving outcomes.

What makes Sunderland Zero different from other nerve injuries on EDX?

Sunderland Zero is associated with chronic ischemia that EDX cannot directly measure, so it is suspected clinically using normal EDX, decreased EMG recruitment, and no atrophy, with early postoperative recovery used for confirmation.

What is the Nerve Injury Calculator (NIC) used for?

The NIC estimates the percent of axonal loss, demyelinating loss, and ischemic axons to predict both timing and quality of recovery, and its clinical utility is demonstrated through three cases.

Sep 29, 2026

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