NEUROPATHIC PAIN (A ABD-ELSAYAED, SECTION EDITOR) Pain Syndromes Secondary to Cluneal Nerve Entrapment Jay Karri 1 & Mani Singh 2 & Vwaire Orhurhu 3 & Mihir Joshi 4 & Alaa Abd-Elsayed 5 # Springer Science+Business Media, LLC, part of Springer Nature 2020 Abstract Purpose of Review The purpose of this review is to provide an overview of the cluneal nerves, present a summary of pain syndromes secondary to clunealgia, and evaluate current literature for diagnostic and treatment modalities. Recent Findings Multiple trials and studies have reported success with numerous modalities ranging from nerve blocks, neuroablation, and even peripheral neuromodulation with varying degrees of clinical benefit. Summary Cluneal nerve entrapment or chronic impingement can cause buttock pain or referred pain to nearby areas including the lower back, pelvic area, or even the lower extremities. Clunealgias and associated pain syndromes can often be challenging to diagnose and differentiate. An appreciation of the pathophysiology of clunealgias can assist with patient selection for interven- tional pain strategies targeted towards the cluneal nerves, including nerve blocks, neuroablation, and peripheral neuromodulation. More research is needed to better delineate the efficacy of these procedures for clunealgias. Keywords Cluneal nerve . Clunealgia . Buttock pain . Chronic pain Background The cluneal nerves are a group of pure sensory nerves that provide direct cutaneous innervation to the buttocks [1–3]. In recent years, clunealgias—pain syndromes secondary to cluneal nerve pathology—have been implicated as the cause of chronic pain that both arises directly from the buttocks and is referred from the lower back, pelvic area, or even lower extremity regions [4–6]. However, many of these pain syndromes are often unspecified in etiology given the vast preponderance of other anatomical causes often associated with these conditions, occasionally concomitantly. Thus, it is suggested that true cluneal nerve involvement may be overlooked in certain populations and presentations. Despite there being a sparsity of high-level evidence clearly delineat- ing the pathophysiology of clunealgia, the cluneal nerves have been targeted via multiple interventional pain procedures with varying degrees of clinical benefit [7–11]. A clear apprecia- tion for the pathophysiology, symptomatology, and diagnos- tics of clunealgias is imperative for appropriate selection of patients and interventional strategies. Cluneal Nerve Anatomy The cluneal nerve complex includes the superior cluneal nerves (SCN), the middle cluneal nerves (MCN), and the in- ferior cluneal nerves (ICN) (Fig. 1)[1–3]. The SCNs are posterior cutaneous branches from the dorsal rami of lower thoracic and upper lumbar spinal nerve roots, usually from the T11-L3 levels [1–3]. The SCN travels from superior to inferior and crosses the pos- terior superior iliac spine (PSIS) while traveling to the quadratus lumborum. The L1–L3 nerves join, pass lateral to the multifidus muscle, and then travel through the This article is part of the Topical Collection on Neuropathic Pain * Jay Karri jaykarri@gmail.com 1 Department of Physical Medicine and Rehabilitation, Baylor College of Medicine, Houston, TX, USA 2 Department of Rehabilitation Medicine, Weill Cornell Medical Center, New York City, NY, USA 3 Department of Anesthesia, Critical Care and Pain Medicine, Division of Pain, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA 4 Department of Anesthesiology, University of Texas Health Science Center, San Antonio, TX, USA 5 Department of Anesthesia, Division of Pain Medicine, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA Current Pain and Headache Reports (2020) 24:61 https://doi.org/10.1007/s11916-020-00891-7