Superior Cluneal Nerve Entrapment Syndrome: Thought to Be Spondylolysis.

A rare but typically overlooked diagnosis in the orthopaedic surgery community is superior cluneal nerve (SCN) entrapment syndrome. The cluneal nerves function as purely sensory fibers, and the SCNs provide cutaneous innervation to the posterior parasacral, gluteal, and posterolateral thigh regions. When irritated, this syndrome can cause acute and chronic lower back pain and lower extremity symptoms. A 14-year-old adolescent girl presented to the clinic for an evaluation of pain in the right side of her lower back. The patient's physical examination showed tenderness to palpation on the right posterior iliac crest seven centimeters from the midline. Her neurologic examination demonstrated normal deep tendon reflexes, muscle strength, and sensation in the L2-S1 dermatomal distribution. Although imaging showed evidence of a left L5 spondylolysis, she responded positively to a steroid injection over the posterior iliac crest but negatively to one over the L5 pars defect. She later underwent a right SCN decompression surgery. After the procedure, she reported at least 90% improvement in her pain and rated it as a one in severity, on a scale of 0 to 10. Research regarding SCN entrapment syndrome has increased in the past several years. However, most of these studies are limited to the adult population. Therefore, more reports highlighting the potential for this syndrome in adolescents are needed as well.

Surgical Outcomes of Common Peroneal Nerve Entrapment Neuropathy Associated with L5 Radiculopathy.

Impingement of the common peroneal nerve, a branch of the L5 nerve root, causes common peroneal nerve entrapment neuropathy (CPNE). Although there are cases of CPNE associated with L5 radiculopathy, surgical intervention's effectiveness remains to be elucidated. This retrospective case-control study aimed to evaluate the efficacy of surgery in patients with CPNE associated with L5 radiculopathy. Twenty-two patients (25 limbs) with surgically treated CPNE between 2015 and 2022 were retrospectively reviewed. The limbs were classified into two groups: group R (limbs of CPNE associated with L5 radiculopathy) and group O (limbs of CPNE without L5 radiculopathy). The durations from onset to surgery, the nerve conduction studies (NCSs), and postoperative improvement rates for motor weakness, pain, and dysesthesia were compared between the groups. Group R included 15 limbs (13 patients), and group O included 10 limbs (9 patients). There were no significant differences in the duration from onset to surgery or abnormal findings of NCS between the two groups. The postoperative improvement rates were 88% and 100% (p = 0.62) for muscle weakness, 87% and 80% (p = 0.53) for pain, and 71% and 56% (p = 0.37) for dysesthesia in group R and group O, respectively, without significant differences between groups. CPNE associated with L5 radiculopathy is common, and the results of the present study showed that the surgical outcomes in such cases were satisfactory and comparable to those in CPNE without L5 radiculopathy.

SYMPATHETIC NERVE ENTRAPMENT POINT INJECTION AS AN ADJUVANT TREATMENT FOR INTRACTABLE CLUSTER HEADACHE: A CASE REPORT.

BACKGROUND: Cluster headache (CH) is characterized by severe unilateral pain ranging from the orbital to the temporal regions with ipsilateral autonomic manifestations. Although most patients respond to drugs or oxygen inhalation, some do not. In this case report, we introduce sympathetic nerve entrapment point injection (SNEPI), a new adjuvant treatment for CH. CASE REPORT: We introduce two CH patients who did not respond well to pharmacological treatment or 100% oxygen inhalation, but who improved after SNEPI. Patient 1, a 42-year-old man, visited the Emergency Department (ED) with severe periorbital right frontal headache accompanied by ipsilateral rhinorrhea, conjunctival injection, and eyelid edema. The symptoms did not fully respond to drugs or oxygen inhalation, but improved after SNEPI into the tender point of the splenius capitis (SC) muscle; there was no further pain for 1 month thereafter. Patient 2, a 26-year-old woman, presented to the ED complaining of severe headache in the right supraorbital-temporal-occipital region with ipsilateral lacrimation and conjunctival congestion. The patient was taking various drugs for CH, but there was no improvement; the symptoms improved dramatically after SNEPI into the tender points of the SC and paraspinal deep muscles (levels T1-2), and the pain was well managed with reduced drug doses for 3 months. Why Should an Emergency Physician Be Aware of This? CH can cause severe acute pain, and sometimes pharmacological treatment or oxygen inhalation is not effective. SNEPI, which is inexpensive and can be easily performed, may be considered as an adjuvant treatment for intractable CH in the ED.

Anterior cutaneous nerve entrapment syndrome in children.

QUESTION: I frequently see adolescents with recurrent abdominal pain in my family medicine clinic. While the diagnosis frequently is a benign condition such as constipation, I recently heard that after 2 years of recurrent pain, an adolescent was diagnosed with anterior cutaneous nerve entrapment syndrome (ACNES). How is this condition diagnosed? What is the recommended treatment? ANSWER: Anterior cutaneous nerve entrapment syndrome, first described almost 100 years ago, is caused by entrapment of the anterior branch of the abdominal cutaneous nerve as it pierces the anterior rectus abdominis muscle fascia. The limited awareness of the condition in North America results in misdiagnosis and delayed diagnosis. Carnett sign-in which pain worsens when using a "hook-shaped" finger to palpate a purposefully tense abdominal wall-helps to confirm if pain originates from the abdominal viscera or from the abdominal wall. Acetaminophen and nonsteroidal anti-inflammatory drugs were not found to be effective, but ultrasound-guided local anesthetic injections seem to be an effective and safe treatment for ACNES, resulting in relief of pain in most adolescents. For those with ACNES and ongoing pain, surgical cutaneous neurectomy by a pediatric surgeon should be considered.

Decompression with Brachioradialis Tenotomy Improves Pain and Quality of Life in Patients with Radial Sensory Nerve Compression.

BACKGROUND: Decompression of the superficial sensory branch of the radial nerve (SBRN) with complete brachioradialis tenotomy may treat pain in both simple and complex cases of SBRN compression neuropathy. METHODS: A retrospective chart review was performed of consecutive patients undergoing this procedure between 2008 and 2020 including postoperative outcomes within 90 days. Data were collected and analyzed, including patient and injury demographics, pain descriptors, and patient-reported pain questionnaire, including reported pain severity and impact on quality of life using visual analogue scale (VAS) instruments. Within-group presurgical and postsurgical analyses and between-group statistical analyses were performed. RESULTS: Thirty-three of 58 patients met inclusion criteria. Median time from symptom onset to surgery was 300 days, and median postoperative follow-up time was 37 days. Twenty-five percent of patients ( n = 8) underwent isolated SBRN decompression. The remainder had concomitant decompression of another radial [ n = 16 (48%) or peripheral [ n = 12 (36%)] entrapment point. Ten of 33 patients (30%) had resolution of pain at final follow-up ( P = 0.004). Median change in worst pain over the previous week was -4 ( P < 0.001), and average pain over the last month was -2.75 ( P < 0.001) on the VAS. The impact of pain on quality of life showed a median change of -3 ( P < 0.001) on the VAS. CONCLUSION: Decompression of the sensory branch of the radial nerve including a complete brachioradialis tenotomy improves pain and quality-of-life VAS scores in patients with both simple compression neuropathy syndrome and complex nerve compression syndrome. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Radial Tunnel Syndrome: Case Report and Comprehensive Critical Review of a Compression Neuropathy Surrounded by Controversy.

Radial tunnel syndrome (RTS) is an uncommon controversial entity thought to cause chronic lateral proximal forearm pain due to compression of the deep branch of the radial nerve, without paralysis or sensory changes. Diagnostic confusion for pain conditions in this region results from inconsistent definitions, terminology, tests, and descriptions in the literature of RTS and "tennis elbow," or lateral epicondylitis. A case of bilateral RTS with signs discordant with traditionally used clinical diagnostic tests was successfully relieved with surgical decompression and led us to perform a comprehensive critical review of the condition. We delineate the controversy surrounding its diagnosis and aim to facilitate appropriate management and identify other areas for further study in this controversial condition. Clinical validity and evidence of anatomical rationale for the traditionally used Maudsley's provocative test is unclear in diagnosis of RTS or in chronic lateral elbow pain, if at all. Neither imaging nor electrophysiological studies contribute to a clinical diagnosis which is supported by short-term improvement after an injection with long-acting local anesthetic and corticosteroid. Accurate diagnosis and treatment of RTS can significantly improve quality of life, but validity and evidence for traditional clinical tests and definitions must be clarified.

Is the cochleovestibular nerve function affected in patients with hemifacial spasm?

Hemifacial spasm (HFS) is a motor disorder caused by the vascular compression of the facial nerve in the posterior fossa. The cochleovestibular nerve is close to the facial nerve and shares the same entry to the periphery, also has disorders caused by vascular compression. We evaluated the cochleovestibular nerve function in patients with HFS based on the hypothesis that vascular compression, which causes HFS, can also affect the nearby cochleovestibular nerve function. The medical charts of 49 patients with surgically confirmed HFS were reviewed retrospectively. The results of the pure-tone threshold, auditory brainstem response (ABR), video head impulse test (vHIT), and magnetic resonance imaging were analyzed. In each patient, the HFS side and the unaffected side were compared in the paired manner. The anterior inferior cerebellar artery was the major offending vessel (69.4%). There were no significant differences in the pure-tone threshold, properties of ABR waves, and vHIT gain. There was no evidence of cochleovestibular nerve compression syndrome in all patients. The angulation of the nerve by the offending vessel was more frequently identified in the HFS side than in the unaffected side (p = 0.040). The effect of HFS on cochleovestibular nerve function is limited.

Cluneal nerve release: a systematic review.

BACKGROUND: Despite the heterogeneity of chronic lower back pain aetiologies, cluneal nerve entrapment remains underdiagnosed and poorly understood with few studies discussing the efficacy of its surgical release. OBJECTIVE: The current study opts to conduct a systematic review reporting on the efficacy of cluneal nerve surgical decompression in patients with an established diagnosis who fail conservative treatment. We aimed to systematically evaluate the literature regarding the clinical outcomes, recurrence of symptoms and revision rates of surgical intervention. METHODS: A systematic review of the English language literature dating up until May 2022 was undertaken according to the PRISMA guidelines. Isolated case reports were excluded. RESULTS: Of a total of 54 articles, 4 studies met the inclusion criteria (three were level IV evidence and one level III evidence) and were analyzed. Overall, 98 patients of mean age 61 years, (range 17-86) underwent cluneal nerve release with a mean follow-up of 25.5 months (6-58 months). There was significant improvement in symptoms post operatively in the 4 studies. No systemic or local complications were encountered during the surgeries. Four articles reported on revision surgery for recurrent symptoms in 8 patients out of 98 with a rate of 8.2%. Of the reoperated patients, 7/8 had new branches released that were not addressed initially and 1 had neurectomy for an adhered pre-released branch. CONCLUSION: This systematic review demonstrated that cluneal nerve decompression has been performed in a total of 98 patients with significant clinical improvement, zero systemic and local complications and revision rates of 8.2% of the cases.

Cluneal neuropathy: Background, diagnosis, and treatment.

BACKGROUND AND AIMS: Cluneal neuropathy is encompassed by three distinct clinical entities. Superior, middle, and inferior cluneal neuralgia make up the constellation of symptoms associated with cluneal neuropathy. Each has its own variable anatomy. MATERIALS AND METHODS: We compiled a narrative review including a review of available literature. We conducted searches on PubMed/MEDLINE, Embase and Google Scholar on the topics of cluneal neuropathy and treatment therein. RESULTS: We collected source articles regarding original descriptions of the disease entities in addition to articles focused on treatment. DISCUSSION: Adjusted incidence rates of superior cluneal neuropathy are 1.6%-11.7%. Accurate diagnosis remains challenging due to the lack of standardized criteria and the aforementioned variability. Treatment may include therapeutic nerve blocks, ablative techniques, neuromodulation, and surgical decompression. Gaps including those related to true incidence and work up exist. Outcomes from interventional studies are limited and mixed due to significant population heterogeneity and non-standardized treatment approaches coupled with very small sample sizes.

The role of a simple questionnaire predicting treatment success in children with ACNES.

BACKGROUND: Some children with chronic abdominal wall pain or groin pain do not have an inguinal hernia but suffer from anterior cutaneous nerve entrapment syndrome (ACNES). Diagnosing ACNES is challenging, especially in children as a diagnostic gold standard is lacking. A paediatric questionnaire containing 17 simple items was earlier found to discriminate between abdominal pain due or ACNES or IBS. Scores range from 0 points (ACNES very unlikely) to 17 points (ACNES very likely). The present study investigates whether this 17-item questionnaire predicted treatment success in children receiving therapy for ACNES. METHODS: Children < 18 years who presented in a single institute between February 2016 and October 2021 with symptoms and signs suggestive of ACNES completed the questionnaire before intake and treatment. Treatment success after 6-8 weeks was defined as self-reported 'pain-free' (group 1), ' > 50% less pain' (group 2) and ' < 50% less pain' (group 3). Group differences regarding sex, age, BMI, symptoms duration and questionnaire scores were analysed. RESULTS: Data of 145 children (female 78%, mean age 14.7 ± 2.3 years, mean BMI 21.1 ± 3.9) were analysed. All children received a diagnostic trigger point injection using an anaesthetic agent, and 75.5% underwent subsequent surgery for untractable pain. The three groups were comparable regarding sex distribution, age, BMI and symptoms duration. In addition, questionnaire scores were not different (group 1: n = 89, mean score 13.4 ± 2.7, group 2: n = 24, 13.4 ± 2.3 and group 3: n = 32, 13.0 ± 2.7, p > 0.05). CONCLUSIONS: Treatment success was attained in 78% of children undergoing surgery for ACNES. A simple questionnaire scoring items associated with abdominal pain did not predict treatment success.

Targeted dorsal root entry zone stimulation alleviates pain due to meralgia paresthetica.

Objective.Meralgia paresthetica (MP) is a mononeuropathy of the exclusively sensory lateral femoral cutaneous nerve (LFCN) that is difficult to treat with conservative treatments. Afferents from the LFCN enter the spinal cord through the dorsal root entry zones (DREZs) innervating L2 and L3 spinal segments. We previously showed that epidural electrical stimulation of the spinal cord can be configured to steer electrical currents laterally in order to target afferents within individual DREZs. Therefore, we hypothesized that this neuromodulation strategy is suitable to target the L2 and L3 DREZs that convey afferents from the painful territory, and thus alleviates MP related pain.Approach.A patient in her mid-30s presented with a four year history of dysesthesia and burning pain in the anterolateral aspect of the left thigh due to MP that was refractory to medical treatments. We combined neuroimaging and intraoperative neuromonitoring to guide the surgical placement of a paddle lead over the left DREZs innervating L2 and L3 spinal segments.Main results.Optimized electrode configurations targeting the left L2 and L3 DREZs mediated immediate and sustained alleviation of pain. The patient ceased all other medical management, reported improved quality of life, and resumed recreational physical activities.Significance.We introduced a new treatment option to alleviate pain due to MP, and demonstrated how neuromodulation strategies targeting specific DREZs is effective to reduce pain confined to specific regions of the body while avoiding disconfort.

Superior cluneal nerve entrapment neuropathy due to lower crossed syndrome: A case with low back pain.

The superior cluneal nerve (SCN) is a sensory nerve known to be originated from the dorsal rami of the lower thoracic and lumbar nerve roots. One of the overlooked causes of low back pain (LBP) is the SCN Entrapment Neuropathy (SCNEN). SCNEN may also be associated with SCN stretching due to lumbar movement and the poor body posture through an increase in the paravertebral muscle tonus. A 59-year-old female patient presented with chronic LBP localized on the right iliac crest and radiating to the right buttock, groin, and leg. She had increased lumbar lordosis and anterior pelvic tilt. She had a tender point over the right iliac crest, and the pain was radiating to the buttock and posterolateral thigh (Tinel sign +). She was diagnosed with lower crossed syndrome and SCNEN, and a therapeutic nerve block was performed. Clinicians should consider SCNEN as a possible diagnosis of LBP.

Diabetic retinopathy as a predictor for peripheral compression neuropathies, a registry-based study.

Diabetes is characterized by hyperglycaemia and entails many complications, including retinopathy and entrapment neuropathies, such as ulnar nerve entrapment (UNE) and carpal tunnel syndrome (CTS). Hyperglycaemia damages the nerves of the retina, as well as peripheral nerves. There is a correlation between entrapment neuropathies and retinopathy in patients with diabetes, but whether patients with diabetic retinopathy are more prone to develop CTS and UNE is uncertain. Hence, the aim was to investigate if retinopathy can be used as a factor predicting the development of CTS and UNE. Data from 95,437 individuals from the National Diabetes Registry were merged with data from the Skåne Healthcare Registry. The population was analysed regarding prevalence of CTS or UNE and retinopathy status. Population characteristics were analysed using the Chi2-test, Student's Independent T-test, and the Mann-Whitney U-test. Two logistic regression models were used to analyse the odds ratio (OR) for development of CTS and UNE depending on retinopathy status, adjusted for possible confounders. Both CTS and UNE were more frequent among those with retinopathy, compared to those without (CTS: 697/10,678 (6.5%) vs. 2756/83,151 (3.3%; p<0.001), (UNE: 131/10,678 (1.2%) vs. 579/83,151 (0.7%; p<0.001)). The OR for developing CTS for individuals with type 1 diabetes and retinopathy was 2.40 (95% CI 2.06-2.81; p<0.001) and of developing UNE was 1.53 (0.96-2.43; p = 0.08). The OR for developing CTS for individuals with type 2 diabetes and retinopathy was 0.93 (0.81-1.08; p = 0.34) and for UNE 1.02 (0.74-1.40; p = 0.90). Diabetic retinopathy is associated with a higher risk of developing CTS and UNE, but the association seems to be mediated by the duration of the diabetes. Higher HbA1c levels, longer diabetes duration and higher BMI are significant risk factors for developing CTS and UNE in type 1 and type 2 diabetes.

Migraine Headaches in Patients with Upper Extremity Compressive Neuropathy.

BACKGROUND: Upper extremity nerve compression syndromes and migraines caused by nerve entrapment have many similarities, including patient presentation, anatomical findings, and treatment by surgical decompression of affected nerves. Parallels between the two conditions point toward the possibility of shared predisposition. The aim of this study was to evaluate the relationship between migraine and upper extremity nerve compression. METHODS: Nine thousand five hundred fifty-eight patients who underwent nerve decompression surgery of the upper extremity (median, ulnar, and radial nerves and thoracic outlet syndrome) as identified by CPT and International Classification of Diseases codes were included in the analysis. International Classification of Diseases codes for migraine and comorbidities included as part of the Elixhauser Comorbidity Index were identified. Bivariate and multivariable logistic regression was performed. RESULTS: Median nerve decompression (OR, 1.3; 95 percent CI, 1.0 to 1.8; p = 0.046) and multiple nerve decompressions (OR, 1.7; 95 percent CI, 1.2 to 2.5; p = 0.008) were independently associated with higher rates of migraine compared to ulnar nerve decompression and thoracic outlet syndrome. Older age and male sex had a negative association with migraine. History of psychiatric disease, rheumatoid arthritis/collagen vascular diseases, hypothyroidism, hypertension, and chronic pulmonary disease were independently associated with migraine headache. CONCLUSIONS: Patients who undergo median and multiple nerve decompression are more likely to experience migraine headache. It is important to recognize this overlap and provide comprehensive patient screening for both conditions. This shared predisposition and better understanding of a common disease mechanism and genetics may provide greater insight into the pathogenesis and therefore treatment of these clinical problems. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, III.

Does Lower Extremity Nerve Decompression Surgery Improve Quality of Life?

BACKGROUND: Entrapment neuropathies are more prevalent in patients with diabetes than in healthy patients. The aim of this study was to assess the effects of lower extremity nerve decompression surgery on quality of life and clarify predictors of this surgical outcome and the incidence of surgical site problems. METHODS: Patients who underwent lower extremity nerve decompression surgery between September of 2017 and March of 2019 were followed prospectively at the outpatient clinic of University Medical Center Utrecht. The common, superficial, and deep peroneal nerve and tibial nerve at the tarsal tunnel and soleal sling were decompressed if an entrapment was diagnosed. The primary study outcome was quality of life as measured by the Norfolk Quality of Life-Diabetic Neuropathy questionnaire. Secondary outcomes of interest were change in Michigan Neuropathy Screening Instrument score, predictors of the Norfolk score at follow-up, and the occurrence of complications. RESULTS: Sixty patients underwent surgery (45 unilateral, 15 bilateral), with a median postoperative follow-up of 13.0 months (interquartile range, 7.3 to 18.0 months). Quality of life improved significantly in this period of observation [baseline median, 46.0 (34.0 to 62.0) versus follow-up median, 37.0 (20.0 to 60.0); p = 0.011], as did Michigan Neuropathy Screening Instrument scores [7.0 (5.0 to 9.0) versus 3.0 (0.0 to 6.5); p < 0.01]. Predictors of quality of life were a higher baseline quality of life score [ß, 0.59 ( p = 0.001)], longer follow-up time [ß, 2.34 ( p < 0.001)], and hypertension [ß, 16.38 ( p = 0.03)]. A total of 26.7 percent of patients had surgical site problems, including wound infections (18.3 percent). CONCLUSIONS: Lower extremity nerve decompression surgery significantly improves quality of life by reducing neuropathy symptoms in patients with lower extremity nerve compressions. Attention should be given to lowering the risk of wound complications. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.

Diagnosis and treatment of pudendal and inferior cluneal nerve entrapment syndrome: a narrative review.

AIM: Pudendal and inferior cluneal nerve entrapment can cause a neuropathic pain syndrome in the sensitive areas innervated by these nerves. Diagnosis is challenging and patients often suffer several years before diagnosis is made. The purpose of the review was to inform healthcare workers about this disease and to provide a basis of anatomy and physiopathology, to inform about diagnostic tools and invasive or non-invasive treatment modalities and outcome. METHODS: A description of pudendal and inferior cluneal nerve anatomy is given. Physiopathology for entrapment is explained. Diagnostic criteria are described, and all non-invasive and invasive treatment options are discussed. RESULTS: The Nantes criteria offer a solid basis for diagnosing this rare condition. Treatment should be offered in a pluri-disciplinary setting and consists of avoidance of painful stimuli, physiotherapy, psychotherapy, pharmacological treatment led by tricyclic antidepressants and anticonvulsants. Nerve blocks are efficient at short term and serve mainly as a diagnostic tool. Pulsed radiofrequency (PRF) is described as a successful treatment option for pudendal neuralgia in patients non-responding to non-invasive treatment. If all other treatments fail, surgery can be offered. Different surgical procedures exist but only the open transgluteal approach has proven its efficacy compared to medical treatment. The minimal-invasive ENTRAMI technique offers the possibility to combine nerve release with pudendal neuromodulation. CONCLUSIONS: Pudendal and inferior cluneal nerve entrapment syndrome are a challenge not only for diagnosis but also for treatment. Different non-invasive and invasive treatment options exist and should be offered in a pluri-disciplinary setting.