The double crush in nerve entrapment syndromes

Musculoaponeurotic Variations along the Course of the Median Nerve in the Proximal Forearm

31 cadaver arms have been dissected to study the variations in the anatomy of the muscles and fibrous arches which might cause compression of the median nerve in the forearm. Pronator teres always had a superficial head and usually a deep head. Flexor digitorum superficialis varied greatly in its site of origin.

The median nerve might be crossed by two, one or no fibro-aponeurotic arches. Gantzer’s muscle, an accessory head of flexor pollicis longus, was present in 45% of cadavers. No ligament of Struthers was found. Possible sites and causes of nerve compression are discussed.

Decompression of the superficial peroneal nerve: clinical outcomes and anatomical study

OBJECTIVE

The authors of this study sought to determine the outcomes of patients undergoing superficial peroneal nerve (SPN) release to treat lower-extremity pain and describe consistent anatomical landmarks to direct surgical planning.

METHODS

This retrospective cohort study examined 54 patients with pain in the SPN distribution who were treated with decompression between 2011 and 2014. Patients rated pain and the effect of pain on quality of life (QOL) on the visual analog scale (VAS) from 0 to 10. Scores were then converted to percentages. Linear regression analysis was performed to assess the impact of the preoperative effect of pain on QOL, age, body mass index (BMI), and preoperative duration of pain on the postoperative effect of pain on QOL. Measurements were made intraoperatively in 13 patients to determine the landmarks for identifying the SPN.

RESULTS

A higher BMI was a negative predictor for improvement in the effect of pain on QOL. A decrease in pain compared with the initial level of pain suggested a nonlinear relationship between these variables. A minority of patients (7 of 16) with a preoperative pain VAS score ≤ 60 reported less pain after surgery. A large majority (30 of 36 patients) of those with a preoperative pain VAS score > 60 reported improvement. Intraoperative measurements demonstrated that the SPN was consistently found to be 5 ± 1.1, 5 ± 1.1, and 6 ± 1.2 cm lateral to the tibia at 10, 15, and 20 cm proximal to the lateral malleolus, respectively.

CONCLUSIONS

A majority of patients with a preoperative pain VAS score > 60 showed a decrease in postoperative pain. A higher BMI was associated with less improvement in the effect of pain on QOL. This information can be useful when counseling patients on treatment options. Based on the intraoperative data, the authors found that the SPN can be located at reliable points in reference to the tibia and lateral malleolus.

The crossed phrenic phenomenon

The cervical spine is the most common site of traumatic vertebral column injuries. Respiratory insufficiency constitutes a significant proportion of the morbidity burden and is the most common cause of mortality in these patients. In seeking to enhance our capacity to treat specifically the respiratory dysfunction following spinal cord injury, investigators have studied the "crossed phrenic phenomenon", wherein contraction of a hemidiaphragm paralyzed by a complete hemisection of the ipsilateral cervical spinal cord above the phrenic nucleus can be induced by respiratory stressors and recovers spontaneously over time. Strengthening of latent contralateral projections to the phrenic nucleus and sprouting of new descending axons have been proposed as mechanisms contributing to the observed recovery. We have recently demonstrated recovery of spontaneous crossed phrenic activity occurring over minutes to hours in C₁-hemisected unanesthetized decerebrate rats. The specific neurochemical and molecular pathways underlying crossed phrenic activity following injury require further clarification. A thorough understanding of these is necessary in order to develop targeted therapies for respiratory neurorehabilitation following spinal trauma. Animal studies provide preliminary evidence for the utility of neuropharmacological manipulation of serotonergic and adenosinergic pathways, nerve grafts, olfactory ensheathing cells, intraspinal microstimulation and a possible role for dorsal rhizotomy in recovering phrenic activity following spinal cord injury.

Multifocal Neuropathy: Expanding the Scope of Double Crush Syndrome

Double crush syndrome (DCS), as it is classically defined, is a clinical condition composed of neurological dysfunction due to compressive pathology at multiple sites along a single peripheral nerve. The traditional definition of DCS is narrow in scope because many systemic pathologic processes, such as diabetes mellitus, drug-induced neuropathy, vascular disease and autoimmune neuronal damage, can have deleterious effects on nerve function. Multifocal neuropathy is a more appropriate term describing the multiple etiologies (including compressive lesions) that may synergistically contribute to nerve dysfunction and clinical symptoms. This paper examines the history of DCS and multifocal neuropathy, including the epidemiology and pathophysiology in addition to principles of evaluation and management.

Differential examination, diagnosis and management for tingling in toes: fellow's case problem

Background

The diagnosis of chronic exertional compartment syndrome can be challenging as other pathologies involving bone, muscle, nerve and vascular structures can mimic the syndrome. The purpose of this Fellow's Case Problem is to describe the clinical decision-making and physical therapy differential diagnosis regarding a 25-year-old patient with un-resolved neurovascular complaints following chronic exertional compartment syndrome surgical release.

Diagnosis

After surgery, the patient's previous complaint of numbness and tingling in the plantar surfaces of her first and second toes of right foot was still present. The patient's concordant symptoms in toes were reproduced proximally in the lumbar spine and distally in the tarsal tunnel.

Discussion

The lumbar spine can refer symptoms to the lower extremities and needs to be ruled out as the source of the patient's complaint whenever neurovascular symptoms such as numbness and tingling are present. The discovery of the relationship of the lumbar spine with the tingling in the toes addressed one of the patient's primary concerns that was not resolved from the surgery.

Level of Evidence

4.

Treatment of the ulnar nerve for overhead throwing athletes undergoing ulnar collateral ligament reconstruction

Ulnar nerve (UN) injuries are a common complaint amongst overhead athletes. The UN is strained during periods of extreme valgus stress at the elbow, especially in the late-cocking and early acceleration phases of throwing. Although early ulnar collateral ligament (UCL) reconstruction techniques frequently included routine submuscular UN transposition, this is becoming less common with more modern techniques. We review the recent literature on the sites of UN compression, techniques to evaluate the UN nerve, and treatment of UN pathology in the overhead athlete. We also discuss our preferred techniques for selective decompression and anterior transposition of the UN when indicated. More recent studies support the use of UN transpositions only when there are specific preoperative symptoms. Athletes with isolated ulnar neuropathy are increasingly being treated with subcutaneous anterior transposition of the nerve rather than submuscular transposition. When ulnar neuropathy occurs with UCL insufficiency, adoption of the muscle-splitting approach for UCL reconstructions, as well as using a subcutaneous UN transposition have led to fewer postoperative complications and improved outcomes. Prudent handling of the UN in addition to appropriate surgical technique can lead to a high percentage of athletes who return to competitive sports following surgery for ulnar neuropathy.

Evaluation of the Tibial Nerve with Shear-Wave Elastography: A Potential Sonographic Method for the Diagnosis of Diabetic Peripheral Neuropathy

Purpose To evaluate the value of shear-wave elastography (SWE) in the detection of diabetic peripheral neuropathy (DPN) of the tibial nerve. Materials and Methods This study was approved by the institutional review board, and written informed consent was obtained from all study participants. The study included 20 diabetic patients with DPN (10 men, 10 women), 20 diabetic patients without DPN (eight men, 12 women), and 20 healthy control subjects (nine men, 11 women). The tibial nerve was examined at 4 cm proximal to the medial malleolus with gray-scale ultrasonography and SWE. The nerve cross-sectional area (in square centimeters) and the mean nerve stiffness (in kilopascals) within the range of the image were recorded. Inter- and intrareader variability, differences among groups, and correlation of clinical and electrophysiologic evaluation were assessed with intraclass correlation coefficients, the Mann Whitney U test, and the Wilcoxon signed rank test. Results Between diabetic patients with and diabetic patients without DPN, mean age (60 years [range, 38-79 years] vs 61 years [range, 46-75 years], respectively), mean duration of diabetes (10 years [range, 1-25 years] vs 10 years [range, 2-26 years]), and mean body mass index (31.4 kg/m² [range, 24.7-48.1 kg/m²] vs 29.8 kg/m² [range, 22.9-44.0 kg/m²]) were not significantly different. Diabetic patients without DPN had significantly higher stiffness values on the right side compared with control subjects (P < .001). Patients with DPN had much higher stiffness values on both sides compared with both diabetic patients without DPN (P < .001) and healthy control subjects (P < .001). A cutoff value of 51.0 kPa at 4 cm proximal to the medial malleolus revealed a sensitivity of 90% (95% confidence interval [CI]: 75.4%, 96.7%) and a specificity of 85.0% (95% CI: 74.9%, 91.7%). Conclusion Tibial nerve stiffness measurements appear to be highly specific in the diagnosis of established DPN. The increased stiffness in subjects without DPN might indicate that the nerve is affected by diabetes. ^© RSNA, 2016 Online supplemental material is available for this article.

Entrapment neuropathies in diabetes mellitus

Neuropathy is a common complication of diabetes mellitus (DM) with a wide clinical spectrum that encompasses generalized to focal and multifocal forms. Entrapment neuropathies (EN), which are focal forms, are so frequent at any stage of the diabetic disease, that they may be considered a neurophysiological hallmark of peripheral nerve involvement in DM. Indeed, EN may be the earliest neurophysiological abnormalities in DM, particularly in the upper limbs, even in the absence of a generalized polyneuropathy, or it may be superimposed on a generalized diabetic neuropathy. This remarkable frequency of EN in diabetes is underlain by a peculiar pathophysiological background. Due to the metabolic alterations consequent to abnormal glucose metabolism, the peripheral nerves show both functional impairment and structural changes, even in the preclinical stage, making them more prone to entrapment in anatomically constrained channels. This review discusses the most common and relevant EN encountered in diabetic patient in their epidemiological, pathophysiological and diagnostic features.

Pain Relief and Health-Related Quality-of-Life Improvement After Microsurgical Decompression of Entrapped Peripheral Nerves in Patients With Painful Diabetic Peripheral Neuropathy

Surgery had been shown to be effective for superimposed peripheral nerve entrapment syndrome in patients with diabetic peripheral neuropathy (DPN), with pain relief and sensation restored. Few studies, however, have reported the quality-of-life outcomes of surgery for the treatment of painful DPN (PDPN). The objective of the present study was to evaluate the effects of microsurgical decompression of multiple entrapped peripheral nerves on pain and health-related quality of life in patients with refractory PDPN of the lower limbs. Eleven patients with intractable PDPN of the lower limbs were recruited for the present study. All the patients underwent microsurgical decompression of the common peroneal nerve, deep peroneal nerve, and posterior tibial nerve. The pain intensity was assessed using the visual analog scale and health-related quality of life was measured using the short-form 36-item quality-of-life survey. Six (54.6%) patients experienced >50% pain relief (both daytime pain and nocturnal pain) at 2 weeks after the decompression procedure and 8 (72.7%) patients at 24 months postoperatively. Two (18.2%) patients experienced a >50% decrease in peak pain at the 2 weeks after the procedure and 8 (72.7%) patients at 24 months. Additionally, the scores from the short-form 36-item quality-of-life survey were significantly improved in the following 2 domains: bodily pain and general health at 2 weeks after the decompression procedure. Also, at 24 months postoperatively, 6 domains had significantly improved, including physical function, bodily pain, general health, social function, role emotional, and mental health. No significant side effects were recorded during the study. Microsurgical decompression of peripheral nerves is an effective and safe therapy for intractable PDPN with superimposed nerve compression.

Carpal tunnel syndrome: mobilization and segmental stabilization

Abstract Introduction: Carpal tunnel syndrome is a compressive neuropathy, frequently seen in women. Conservative treatment for carpal tunnel syndrome focuses on control of symptoms and the nervous path, due to the possibility of double compression. Objective: To assess whether a protocol with emphasis on motor control techniques, including segmental cervical stabilization and neural mobilization, has better results in mechanical reorganization and reduction of symptoms when compared with classic therapeutic exercise techniques in the conservative treatment of carpal tunnel syndrome. Methods: This pilot study was a randomized, double-blind clinical trial, involving 11 women with an average age of 54 (± 6) years, allocated to either a classical kinesiotherapy group (CG) or experimental group (EG). The intervention spanned 12 weeks, with assessments prior to and following therapy, using the monofilament test, handgrip dynamometer, and BCTQ, DASH, and PRWE questionnaires. All normally distributed data was analysed with Student's T-tests. Results: Both groups exhibited an increase in grip strength and relief of symptoms with improved functionality. There was a significant reduction in sensitivity noted in the CG group, and a significant increase in grip strength observed in the EG group. Conclusion: The experimental protocol group exhibited better results in mechanical reorganization, reflected in increased strength, sensitivity, and improved functionality, when compared to the group with conventional therapeutic exercise, but without the same symptomatic reduction.

Cubital Tunnel Syndrome: A Retrospective Review of 53 Anterior Subcutaneous Transpositions

Fifty-three cases of cubital tunnel syndrome were treated by anterior subcutaneous transposition of the ulnar nerve. All patients were assessed by an independent examiner at a mean follow-up of 32 months. McGowan’s rating scale, as modified by Goldberg, was used preoperatively and at follow-up. Preoperatively, five cases were classified grade I, 37 grade IIA, eight grade IIB and three grade III. Thoracic outlet syndrome was also present in 7 cases. At follow-up, 44 cases were grade 0, three grade I, five grade IIA and one grade IIB. Forty-four of the 53 cases had resolved and the other nine had improved. Subcutaneous transposition is a reliable and effective surgical option. The result is less satisfactory if a thoracic outlet syndrome is also present.

Pectoralis Minor Syndrome: Case Presentation and Review of the Literature

We present a case of a healthy young female with axillary vein compression caused by the pectoralis minor muscle. Diagnosis was made by clinical findings and dynamic venography. After pectoralis minor tenotomy, the patient had total resolution of her symptoms. Compression of the axillary vein by the pectoralis minor is a rare entity that needs a careful exam and imaging to reach its diagnosis and establish the appropriate treatment.

Supraorbital Rim Syndrome: Definition, Surgical Treatment, and Outcomes for Frontal Headache

Background:

Supraorbital rim syndrome (SORS) is a novel term attributed to a composite of anatomically defined peripheral nerve entrapment sites of the supraorbital rim region. The SORS term establishes a more consistent nomenclature to describe the constellation of frontal peripheral nerve entrapment sites causing frontal headache pain. In this article, we describe the anatomical features of SORS and evidence to support its successful treatment using the transpalpebral approach that allows direct vision of these sites and the intraconal space.

Methods:

A retrospective review of 276 patients who underwent nerve decompression or neurectomy procedures for frontal or occipital headache was performed. Of these, treatment of 96 patients involved frontal surgery, and 45 of these patients were pure SORS patients who underwent this specific frontal trigger site deactivation surgery only. All procedures involved direct surgical approach through the upper eyelid to address the nerves of the supraorbital rim at the bony rim and myofascial sites.

Results:

Preoperative and postoperative data from the Migraine Disability Assessment Questionnaire were analyzed with paired t test. After surgical intervention, Migraine Disability Assessment Questionnaire scores decreased significantly at 12 months postoperatively (P < 0.0001).

Conclusions:

SORS describes the totality of compression sites both at the bony orbital rim and the corrugator myofascial unit for the supraorbital rim nerves. Proper diagnosis, full anatomical site knowledge, and complete decompression allow for consistent treatment. Furthermore, the direct, transpalpebral surgical approach provides significant benefit to allow complete decompression.

An Epidemiological Study of Neuropathic Pain Symptoms in Canadian Adults

The reported prevalence of neuropathic pain ranges from 6.9% to 10%; however the only Canadian study reported 17.9%. The objective of this study was to describe the epidemiology of neuropathic pain in Canada. A cross-sectional survey was conducted in a random sample of Canadian adults. The response rate was 21.1% (1504/7134). Likely or possible neuropathic pain was defined using a neuropathic pain-related diagnosis and a positive outcome on the Self-Report Leeds Assessment of Neuropathic Symptoms and Signs pain scale (S-LANSS) or the Douleur Neuropathique 4 (DN4) Questions. The prevalence of likely neuropathic pain was 1.9% (S-LANSS) and 3.4% (DN4) and that of possible neuropathic pain was 5.8% (S-LANSS) and 8.1% (DN4). Neuropathic pain was highest in economically disadvantaged males. There is a significant burden of neuropathic pain in Canada. The low response rate and a slightly older and less educated sample than the Canadian population may have led to an overestimate of neuropathic pain. Population prevalence varies by screening tool used, indicating more work is needed to develop reliable measures. Population level screening targeted towards high risk groups should improve the sensitivity and specificity of screening, while clinical examination of those with positive screening results will further refine the estimate of prevalence.

Local Anesthetic-Induced Neurotoxicity

This review summarizes current knowledge concerning incidence, risk factors, and mechanisms of perioperative nerve injury, with focus on local anesthetic-induced neurotoxicity. Perioperative nerve injury is a complex phenomenon and can be caused by a number of clinical factors. Anesthetic risk factors for perioperative nerve injury include regional block technique, patient risk factors, and local anesthetic-induced neurotoxicity. Surgery can lead to nerve damage by use of tourniquets or by direct mechanical stress on nerves, such as traction, transection, compression, contusion, ischemia, and stretching. Current literature suggests that the majority of perioperative nerve injuries are unrelated to regional anesthesia. Besides the blockade of sodium channels which is responsible for the anesthetic effect, systemic local anesthetics can have a positive influence on the inflammatory response and the hemostatic system in the perioperative period. However, next to these beneficial effects, local anesthetics exhibit time and dose-dependent toxicity to a variety of tissues, including nerves. There is equivocal experimental evidence that the toxicity varies among local anesthetics. Even though the precise order of events during local anesthetic-induced neurotoxicity is not clear, possible cellular mechanisms have been identified. These include the intrinsic caspase-pathway, PI3K-pathway, and MAPK-pathways. Further research will need to determine whether these pathways are non-specifically activated by local anesthetics, or whether there is a single common precipitating factor.

Diagnostic Ultrasound of the Soleal Sling

The soleal sling may be a site of tibial nerve entrapment. Objective diagnosis of this syndrome is difficult with current nerve conduction study techniques, magnetic resonance imaging, and neurosensory testing. Diagnostic ultrasound is ideally suited to visualize the tibial nerve statically and dynamically as it enters the soleal sling, thus making an objective diagnosis of soleal sling impingement much easier.

Hand Therapy Treatment

Clinical pain is multifactorial. It is not simply the consequences of a "switching on" of the pain system in the periphery, but also excitability of central nociceptive areas. For pain management to be successful in treating the upper extremity both the peripheral and central symptoms must be targeted. The patient education process must ensure that patients understand their symptoms and treatment program. This article discusses recent advancements in the neuroscience of pain that impact evolving strategies to identify and treat the pain mechanisms.

Ultrasound Diagnosis of Double Crush Syndrome of the Ulnar Nerve by the Anconeus Epitrochlearis and a Ganglion

Double compression of the ulnar nerve, including Guyon's canal syndrome associated with cubital tunnel syndrome caused by the anconeus epitrochlearis muscle, is a very rare condition. We present a case of double crush syndrome of the ulnar nerve at the wrist and elbow in a 55-year-old man, as well as a brief review of the literature. Although electrodiagnostic findings were consistent with an ulnar nerve lesion only at the elbow, ultrasonography revealed a ganglion compressing the ulnar nerve at the hypothenar area and the anconeus epitrochlearis muscle lying in the cubital tunnel. Careful physical examination and ultrasound assessment of the elbow and wrist confirmed the clinical diagnosis prior to surgery.

Nerve ultrasound identifies abnormalities in the posterior interosseous nerve in patients with proximal radial neuropathies

INTRODUCTION

The radial nerve and posterior interosseous nerve (PIN) are prone to injury at multiple sites. Electrodiagnostic (EDx) studies may only identify the most proximal lesion. Nerve ultrasound could augment EDx by visualizing additional pathology.

METHODS

This investigation was a retrospective examination of ultrasound and EDx from 26 patients evaluated for posterior cord/radial/PIN lesions.

RESULTS

Eighteen of 26 patients had abnormalities on EDx (15 radial, 2 PIN, 1 posterior cord). Ultrasound identified 15 of 18 (83%) of the EDx abnormalities and provided additional diagnostic information. In 6 of 15 (40%) patients with EDx evidence of radial neuropathy, ultrasound identified both radial nerve enlargement and additional, unsuspected PIN enlargement (53% to 339% enlarged vs. unaffected side). Ultrasound also identified: nerve (dis)continuity at the trauma site (n = 8); and nerve tumor (n = 2; 1 with normal EDx).

CONCLUSION

In radial neuropathy, ultrasound often augments EDx studies and identifies a second lesion in the PIN. Further studies are required to determine the etiology and significance of this additional distal pathology.

The utility of anatomic diagnosis for identifying femoral nerve palsy following gynecologic surgery

We describe a case in which an anatomic diagnosis was useful for diagnosing and estimating the cause of femoral nerve palsy following gynecologic surgery. A 49-year-old female received general and epidural anesthesia for radical ovarian cancer surgery. Although injection pain was noted in the left medial shin with 1 % mepivacaine administered as a test dose, the catheter was left indwelling because it improved her symptoms. The surgery, which lasted 195 min, was performed in the lithotomy position, and a self-retained retractor was used to gain a good surgical field. Postoperatively, the patient complained of difficulty in stretching her knee joint and left lower limb paresthesia that did not improve after stopping continuous epidural administration. A spinal cord injury related to epidural anesthesia was suspected because the sites of sensory impairment and epidural injection pain were the same; however, the patient had greater weakness of the quadriceps muscle than the iliopsoas, and no other muscle weakness was observed. These findings and previous reports suggest that her femoral nerve palsy was caused by compression of the inguinal ligament from the self-retaining retractor and lithotomy position. Twenty months after surgery, her muscle strength had fully recovered.

Entrapment and traumatic neuropathies of the elbow and hand: An imaging approach

Ultrasound and magnetic resonance imaging currently offer a detailed analysis of the peripheral nerves. Compressive and traumatic nerve injuries are the two main indications for imaging investigation of nerves with several publications describing the indications, technique and diagnostic capabilities of imaging signs. Investigation of entrapment neuropathies has three main goals, which are to confirm neuronal distress, search for the cause of nerve compression and exclude a differential diagnosis on the entire nerve. For traumatic nerve injuries, imaging, predominantly ultrasound, occasionally provides essential information for management including the type of nerve lesion, its exact site and local extension.

Prevention of perioperative limb neuropathies in abdominal free flap breast reconstruction

BACKGROUND AND AIMS

Perioperative peripheral neuropathies are a significant cause of post-operative morbidity in patients undergoing prolonged procedures. The aims of this study were to determine the incidence and possible causes of peripheral neuropathy in patients undergoing abdominal free flap breast reconstruction and to develop methods of ameliorating this problem.

METHODS

A 4-year retrospective study of patients undergoing abdominal free flap breast reconstruction by a single surgeon and anaesthetist was undertaken to determine the incidence and potential causes of perioperative neuropathy. A new positioning protocol was introduced to minimise the stretch on the brachial plexus and to protect peripheral nerves from compression forces. In addition, regular intraoperative physiotherapy was introduced. A prospective study was then conducted on patients managed by the same team to evaluate the effect of this change in practice on the subsequent incidence of peripheral neuropathies.

RESULTS

Over the 4-year retrospective period, 93 consecutive patients underwent abdominal free flap breast reconstruction, six of whom (6.5%) developed a peripheral neuropathy. Following the introduction of the new positioning protocol, prospective data collected on 65 consecutive patients showed no further occurrences of perioperative neuropathy (p = 0.04). There were no significant differences in the characteristics between the two cohorts.

CONCLUSION

Perioperative peripheral neuropathy in abdominal free flap breast reconstruction is a preventable problem. This paper presents a peripheral neuropathy prevention protocol for managing these patients.

The prevalence of tarsal tunnel syndrome in patients with lumbosacral radiculopathy

PURPOSE

Tarsal tunnel syndrome (TTS) is a painful foot condition. Lumbosacral radiculopathy (LR) may also present with symptoms occurring in TTS. However, no studies have been reported to determine the possible coexistence of these two conditions. The aim of our study was to identify the prevalence of TTS in patients with confirmed LR and to analyze the clinical and electrodiagnostic features of patients with both TTS and LR.

METHODS

Medial and lateral plantar nerve mixed studies, peroneal motor studies and deep peroneal sensory studies were performed in 81 normal subjects and 561 patients with LR. The Tinel's test and other provocative tests were performed in the LR patient group, and the clinical symptoms of TTS were also analyzed. The frequency of TTS was investigated in all radiculopathy group patients with different nerve root lesions.

RESULTS

Concomitant TTS was found in 27 (4.8%) patients with LR. Abnormal results of sensory/mixed conduction tests were observed in 25/27 (92.6%) patients, and 11/27 (40.7%) patients had abnormal results of motor conduction tests. Positivity for the Tinel's test and special provocative tests was found in 15/27 (55.6%) and 17/27 (63.0%) patients, respectively. Overall, 9/27 (33.3%) patients had typical symptoms, and suspicious clinical symptoms were found in the other 14/27 (51.9%) patients. The frequency of coexisting TTS was not statistically different among the single-level L4, L5 or S1 radiculopathy, or between the single-level and multi-level radiculopathies (P > 0.05).

CONCLUSIONS

The findings suggest that the prevalence of TTS is significant in patients with LR. Thus, more caution should be paid when diagnosing and managing patients with LR due to the possible existence of TTS, as their management strategies are quite different.

Double Crush Syndrome

Double crush syndrome is a distinct compression at two or more locations along the course of a peripheral nerve that can coexist and synergistically increase symptom intensity. In addition, dissatisfaction after treatment at one site may be the result of persistent pathology at another site along a peripheral nerve. Double crush syndrome is a controversial diagnosis; some scientists and surgeons believe it is an illness construction that may do more harm than good because it emphasizes an objective pathophysiologic explanation for unexplained symptoms, disability, and dissatisfaction that may be more psychosocially mediated. However, peripheral neuropathy may coexist with compressive neuropathy and contribute to suboptimal outcomes following nerve decompression. To better manage patients' expectations, treating practitioners should be aware of the possibility of concomitant cervical radiculopathy and carpal tunnel syndrome, as well as the presence of underlying systemic neuropathy.

Immediate and durable clinical improvement in the non-operated hand after contralateral surgery for patients with bilateral Carpal Tunnel Syndrome

BACKGROUND

Little is known about clinical improvement in the non-operated hand after unilateral surgery for patients who present with bilateral carpal tunnel syndrome (CTS). In this prospective study of patients with bilateral CTS, we evaluated the clinical effects on the non-operated hand following unilateral contralateral carpal tunnel surgical release.

MATERIAL AND METHODS

During a consecutive period of 22 months, 69 patients with bilateral CTS underwent unilateral open carpal tunnel release. Bilateral subjective and objective evaluations were performed pre-operatively, at days 2, 15 and 180 after surgery. Subjective evaluations, analysed with Student t test, included the Boston-Levine symptom severity score and a visual analogue scale including pain, nocturnal symptoms and numbness. A telephone survey was conducted 12 months after surgery.

RESULTS

The Boston-Levine severity score of the contralateral non-operated hand decreased from 2.70 pre-operatively to 1.70 at 2 days (p < 0.001). The visual analogue pain score decreased at 2 days for 61 patients (88 %), whereas the nocturnal symptoms decreased or disappeared in 63 cases (91 %) and the paresthesia in 52 cases (75 %) (ps < 0.001). These beneficial effects were stable in time with no statistically significant change at 180 days. Overall, 58 patients (84 %) observed a total resolution or a significant improvement in their symptoms at 6 months. At 12 months, 100 % of patients responded to a telephone survey. Fifty one of them (74 %) reported minimal or no symptoms on the non-operated hand. Linear regression (analysis of variance [ANOVA]) showed that gender, age, professional status, duration of pre-operative symptoms and severity of electrophysiological disturbances were not predictive of post-operative evolution in the non-operated hand after unilateral surgery for CTS.

The "hierarchical" Scratch Collapse Test for identifying multilevel ulnar nerve compression

BACKGROUND

The Scratch Collapse Test (SCT) is used to assist in the clinical evaluation of patients with ulnar nerve compression. The purpose of this study is to introduce the hierarchical SCT as a physical examination tool for identifying multilevel nerve compression in patients with cubital tunnel syndrome.

METHODS

A prospective cohort study (2010-2011) was conducted of patients referred with primary cubital tunnel syndrome. Five ulnar nerve compression sites were evaluated with the SCT. Each site generating a positive SCT was sequentially "frozen out" with a topical anesthetic to allow determination of both primary and secondary ulnar nerve entrapment points. The order or "hierarchy" of compression sites was recorded.

RESULTS

Twenty-five patients (mean age 49.6 ± 12.3 years; 64 % female) were eligible for inclusion. The primary entrapment point was identified as Osborne's band in 80 % and the cubital tunnel retinaculum in 20 % of patients. Secondary entrapment points were also identified in the following order in all patients: (1) volar antebrachial fascia, (2) Guyon's canal, and (3) arcade of Struthers.

CONCLUSION

The SCT is useful in localizing the site of primary compression of the ulnar nerve in patients with cubital tunnel syndrome. It is also sensitive enough to detect secondary compression points when primary sites are sequentially frozen out with a topical anesthetic, termed the hierarchical SCT. The findings of the hierarchical SCT are in keeping with the double crush hypothesis described by Upton and McComas in 1973 and the hypothesis of multilevel nerve compression proposed by Mackinnon and Novak in 1994.

Spectrum of suprascapular nerve lesions: normal and abnormal neuromuscular imaging appearances on 3-T MR neurography

OBJECTIVE. In this article, we will review the normal anatomy and imaging features of various neuromuscular abnormalities related to suprascapular neuropathy. CONCLUSION. Suprascapular neuropathy can be difficult to distinguish from rotator cuff pathology, plexopathy, and radiculopathy. Electrodiagnostic studies are considered the reference standard for diagnosis; however, high-resolution 3-T MR neurography (MRN) can play an important role. MRN enables direct visualization of the nerve and simultaneous assessment of the cervical spine, brachial plexus, and rotator cuff.

An Association between Carpal Tunnel Syndrome and Migraine Headaches-National Health Interview Survey, 2010

Background:

Migraine headaches have not historically been considered a compression neuropathy. Recent studies suggest that some migraines are successfully treated by targeted peripheral nerve decompression. Other compression neuropathies have previously been associated with one another. The goal of this study is to evaluate whether an association exists between migraines and carpal tunnel syndrome (CTS), the most common compression neuropathy.

Methods:

Data from 25,880 respondents of the cross-sectional 2010 National Health Interview Survey were used to calculate nationally representative prevalence estimates and 95% confidence intervals (95% CIs) of CTS and migraine headaches. Logistic regression was used to calculate adjusted odds ratios (aORs) and 95% CI for the degree of association between migraines and CTS after controlling for known demographic and health-related factors.

Results:

CTS was associated with older age, female gender, obesity, diabetes, and smoking. CTS was less common in Hispanics and Asians. Migraine was associated with younger age, female gender, obesity, diabetes, and current smoking. Migraine was less common in Asians. Migraine prevalence was 34% in those with CTS compared with 16% in those without CTS (aOR, 2.60; 95% CI, 2.16–3.13). CTS prevalence in patients with migraine headache was 8% compared with 3% in those without migraine headache (aOR, 2.67; 95% CI, 2.22–3.22).

Conclusions:

This study is the first to demonstrate an association between CTS and migraine headache. Longitudinal and genetic studies with physician verification of migraine headaches and CTS are needed to further define this association.

Nerve entrapment: update

LEARNING OBJECTIVES

After reading this article, the participant should be able to: 1. Understand the pathophysiology of chronic nerve compression. 2. Describe the evaluation of a patient presenting with compression neuropathy. 3. Discuss the current controversies in the management of compression neuropathies. 4. Describe the treatment of common compression neuropathies, including carpal and cubital tunnel syndromes.

SUMMARY

Nerve entrapment syndromes are common in the general population, and are managed by a wide variety of medical and surgical specialists. A thorough understanding of the pathophysiology of nerve compression and appropriate clinical workup are critical in the overall management of these conditions. There remain several topics of controversy regarding the surgical management of nerve entrapment syndromes, including multiple points of nerve compression, carpal tunnel release under local anesthesia, open versus endoscopic decompression surgery, the "best" operation for primary cubital tunnel surgery, and revision decompression surgery. This article attempts to provide a concise summary of the advances in the basic and clinical science of peripheral nerve entrapment.

Thoracic outlet and pectoralis minor syndromes

Compression of the neurovascular bundle to the upper extremity can occur above or below the clavicle; thoracic outlet syndrome (TOS) is above the clavicle and pectoralis minor syndrome is below. More than 90% of cases involve the brachial plexus, 5% involve venous obstruction, and 1% are associate with arterial obstruction. The clinical presentation, including symptoms, physical examination, pathology, etiology, and treatment differences among neurogenic, venous, and arterial TOS syndromes. This review details the diagnostic testing required to differentiate among the associated conditions and recommends appropriate medical or surgical treatment for each compression syndrome. The long-term outcomes of patients with TOS and pectoralis minor syndrome also vary and depend on duration of symptoms before initiation of physical therapy and surgical intervention. Overall, it can be expected that >80% of patients with these compression syndromes can experience functional improvement of their upper extremity; higher for arterial and venous TOS than for neurogenic compression.

Median neuropathy at the wrist as an early manifestation of diabetic neuropathy

Aims/Introduction

To elucidate the clinical significance of median neuropathy at the wrist (MN) in patients with diabetes.

Materials and Methods

In total, 340 patients with diabetes who were hospitalized for glycemic control were enrolled in the present study. The diagnoses of MN and diabetic polyneuropathy (DPN) were based on electrophysiological criteria. A total of 187 patients were divided into four subgroups: patients without MN or DPN; patients with MN without DPN; patients with MN and DPN; and patients with DPN without MN. Intergroup comparisons of clinical characteristics and results of nerve conduction studies were carried out.

Results

A total of 71 patients had neither MN nor DPN; 25 had MN, but no DPN; 55 had MN and DPN; and 36 had DPN, but no MN. In comparison with the MN and DPN group, the MN without DPN group included more patients in the early phase of diabetes (diagnosed within the past 5 years) and fewer patients with diabetic microangiopathy. Comparative median nerve conduction studies showed significantly lower motor and sensory nerve conduction velocities, longer F-wave latencies, and smaller sensory nerve action potentials in patients with MN and DPN than in those without DPN.

Conclusions

MN in patients with diabetes could be attributed to an impairment in axonal function at common entrapment sites, and could be used to identify an early manifestation of diabetic neuropathy.