Median Mononeuropathy Research Articles

Diagnostic utility of shear wave elastography in musculoskeletal injuries: A narrative review.

Shear wave elastography (SWE) is an emerging and promising ultrasound modality, and is more recently employed in the diagnosis of musculoskeletal (MSK) pathologies. SWE evaluates tissue stiffness by measuring the speed of propagating acoustic waves through body tissue structures. Knowing the variations in stiffness of MSK soft tissue can provide helpful diagnostic insight for the evaluation of pathology in muscles, tendons, ligaments, nerves, and other soft tissues. The goal of this review is to synthesize recent literature on the utility of SWE for MSK pathology diagnosis. This review reveals that SWE adds important diagnostic data for the evaluation of several pathologies, such as median mononeuropathy at the wrist, Achilles tendinopathy, and plantar fasciitis. The review also reveals a lack of evidence pertaining to appropriate standardization of use and the connection to reliable and valid diagnostic benefit in the clinical setting.

Chapter 5 - Other median neuropathies

Median mononeuropathy is common, with carpal tunnel syndrome the most frequently encountered acquired mononeuropathy in clinical practice. However, other disorders of the median nerve and many known anatomical variants can lead to misdiagnosis and unexpected surgical complications if their presence is not correctly identified. A number of inherited and acquired disorders can affect the median nerve proximal to the wrist, alone or accompanied by other affected peripheral nerves. Recognizing other disorders that can masquerade as median mononeuropathies can avoid misdiagnosis and misguided management. This chapter explores median nerve anatomical variants, disorders, and lesions, emphasizing the need for careful examination and electrodiagnostic study in the localization of median neuropathy.

Vasculitis presenting as carpal tunnel syndrome: a case report

BackgroundCarpal tunnel syndrome is the most common focal mononeuropathy which presents with pain in the wrist and hand, paresthesia, loss of sensation in the distribution of the median nerve, and in more severe cases, weakness and atrophy of the thenar muscles. Meanwhile, carpal tunnel syndrome can present as an initial manifestation of underlying systemic vasculitis disorder and result in severe physical disabilities.Case presentationA 27-year-old Iranian man was referred to our electrodiagnosis center with a clinical diagnosis of carpal tunnel syndrome in April 2020. Surgical intervention had been taken into account for him because of unsuccessful conservative therapies. On admission, thenar eminence was reduced. Electrodiagnostic findings were not compatible with median nerve entrapment at the wrist. All sensory modalities in the distribution of the right median nerve were decreased. Additionally, a mild increase in erythrocyte sedimentation rate was noted in laboratory tests. Because of the high vasculitis suspicion, we recommended the nerve biopsy and/or starting a high-dose corticosteroid. However, the surgery release was performed. After 6 months, the patient was referred for progressive weakness and numbness in the upper and lower limbs. After documentation of vasculitis neuropathy by biopsy, a diagnosis of non-systemic vasculitic neuropathy was confirmed. A rehabilitation program started immediately. Rehabilitation led to gradual improvement and recovery of function and muscle strength, and no complications remained, except mild leg paralysis.ConclusionsPhysicians should be suspicious of the median nerve vasculitis mononeuropathy in a patient with carpal tunnel syndrome-like symptoms. Median nerve vasculitis mononeuropathy as an initial presenting feature of vasculitis neuropathy can further result in severe physical impairments and disabilities.

Eficacia del tratamiento de rehabilitación para el síndrome del túnel carpiano: un ensayo clínico controlado aleatorizado

Introduction and objectiveCarpal tunnel syndrome is the most common median nerve mononeuropathy. There are multiple conservative treatments, invasive (corticoid injections [CI]) and non-invasive (splinting, therapeutic ultrasound [TUS], laser, exercise). However, the treatment choice is controversial. The aim was to determine the efficacy of conservative treatment to improve the clinical and electrophysiological evaluations. MethodsOutpatients referred whit carpal tunnel syndrome clinical diagnosis to perform nerve conduction study (NCS) were included, without chronic or metabolic diseases that affect the peripheral nerves, without carpal tunnel syndrome treatment and with mild or moderate axonotmesis or neuropraxia in NCS baseline. Patients who signed informed consent forms were randomized in three treatment groups (Group 1: TUS+splint; Group 2: CI+splint and Group 3: TUS+CI+splint) were referred for clinical evaluations. The NCS was performed in each patient at baseline, fourth and eighth weeks by the same physiatrist and the clinical evaluations were performed at baseline and the final follow-up. ResultsThirty patients were included; mean age was 50.7±7.5 years and all of them females, without differences in NCS or clinical variables in the baseline evaluations. All groups exhibited improvement in some clinical and electrophysiological variables in the final evaluation, though only group 3 showed improvement on median/ulnar nerves sensory peak latency difference (1.2±0.4 vs. 0.4±0.4; p=0.001) starting in week four. ConclusionsThe conservative treatment in patients with CTS improves NCS and clinical variables, including the most sensitive electrophysiological test (medial/ulnar difference), though if we combined three treatments (splint+TUS+CI), the improvement was found to be faster and remarkable.

IDIOPATHIC TASTE IMPAIRMENT IN A YOUNG WOMAN: A CASE REPORT

ABSTRACT Background: The underlying cause of taste impairment includes damage in the central or peripheral nervous system, nutrition deficiency, systemic disease, or idiopathic. This condition usually occurs with advancing age. Taste alteration may affect the patient’s psychological aspect and causing malnutrition or even develop into more serious health problems. Purpose: This report aims to evaluate an unusual partial ageusia in a young woman and to review articles with idiopathic taste disorders. Case: A 33-year-old woman was referred to the Department of Oral Medicine from the neurology department with a primary diagnosis of migraine and median nerve mononeuropathy. The patient also complained of loss of tastes (salty, bitter, and sour) accompanied by numbness on the palate and left buccal mucosa for the past two weeks. Case Management: The patient was given a 0.12% chlorhexidine digluconate mouthwash and 25 mg zinc tablets twice a day. After 2 weeks, she can identify bitter, and followed by sweet and sour in the next few weeks, as well as improvement of the numbness. Eighteen studies of idiopathic taste disorders from 1991-2021 have been reported in the literature. Conclusion: Taste disorders with unknown aetiology may happen in young individuals. Zinc has been proven as a beneficial micronutrient to treat patients with idiopathic taste impairment. Dentists should consider this approach to resolve the symptoms and accelerate the healing process of possible co-occurrence systemic diseases. Keywords: Ageusia, idiopathic, Taste dysfunction, Treatment

CARPAL TUNNEL SYNDROME, GENERALITIES, MANAGEMENT AND TREATMENT

Introduction: Carpal tunnel syndrome (CTS), also called median wrist mononeuropathy, is the most frequent nerve compression syndrome reaching up to 90%. Objective: To detail the current information related to carpal tunnel syndrome and its management, as well as to analyze the conservative and surgical treatment of this disease. Methodology: A total of 27 articles were analyzed in this review, including review and original articles, as well as clinical cases, of which 18 bibliographies were used because the other 9 articles were not relevant to this study. The sources of information were PubMed, Google Scholar and Cochrane; the terms used to search for information in Spanish, Portuguese and English were: túnel carpiano, síndrome do túnel do carpo e AINEs, carpal tunnel syndrome, treatment in patients with carpal tunnel syndrome and corticoids in carpal tunnel. Results: Wrist flexion and extension increase pressure in the carpal canal, leading to the following symptoms: pain, numbness and paresthesia. Corticosteroid injections are recommended in mild to moderate carpal tunnel syndrome. Endoscopic carpal tunnel release has less postoperative pain, earlier recovery in grip and pinch strength, compared to open release. Postoperative complications are infrequent and most are minimal and transient. Conclusions: Carpal tunnel syndrome is the oppression of the median nerve at the level of the wrist joint, which may be accompanied with limitation in epineural and axoplasmic blood flow, leading to nerve dysfunction, edema, and scarring. The diagnosis of carpal tunnel syndrome has been made through a mixture of clinical history and physical examination maneuvers, however, the use of ultrasound and electrodiagnostic tests is now being supported. There are conservative and surgical treatments, among which evidence shows that steroid injection and carpal tunnel release are effective and present good treatment results. KEY WORDS: Syndrome, tunnel, carpal, mononeuropathy

Automatic Electrodiagnosis of Carpal Tunnel Syndrome Using Machine Learning.

Recent literature has revealed a long discussion about the importance and necessity of nerve conduction studies in carpal tunnel syndrome management. The purpose of this study was to investigate the possibility of automatic detection, based on electrodiagnostic features, for the median nerve mononeuropathy and decision making about carpal tunnel syndrome. The study included 38 volunteers, examined prospectively. The purpose was to investigate the possibility of automatically detecting the median nerve mononeuropathy based on common electrodiagnostic criteria, used in everyday clinical practice, as well as new features selected based on physiology and mathematics. Machine learning techniques were used to combine the examined characteristics for a stable and accurate diagnosis. Automatic electrodiagnosis reached an accuracy of 95% compared to the standard neurophysiological diagnosis of the physicians with nerve conduction studies and 89% compared to the clinical diagnosis. The results show that the automatic detection of carpal tunnel syndrome is possible and can be employed in decision making, excluding human error. It is also shown that the novel features investigated can be used for the detection of the syndrome, complementary to the commonly used ones, increasing the accuracy of the method.

Shoulder Pain-Wheelchair Basketball

HISTORY: 39 year old male wheelchair basketball player was referred for shoulder pain and need for potential glenohumeral joint injection. He had experienced one year of left-sided shoulder pain that began after colliding with an opponent at high velocity during a game. At the time of the trauma, he had sudden onset burning left sided neck pain that radiated down his arm to his left thumb. He noticed that raising his left arm above his shoulder worsened the shoulder pain. Additionally, he noticed left-sided weakness with elbow flexion and shoulder abduction that made wheelchair transfers difficult. PHYSICAL EXAMINATION: 4/5 strength with left shoulder abduction and elbow flexion. Active left shoulder abduction and flexion was limited to 90 degrees, due to pain. Empty can, Hawkin’s, and Neer’s tests caused left anterior shoulder pain. Decreased sensation over the left lateral upper arm to pinprick and light touch. Hoffman’s elicited on the left. Reflexes: 3+ left biceps. Cervical forward and left lateral flexion limited due to pain. Left Spurling’s exacerbated shoulder pain. DIFFERENTIAL DIAGNOSIS 1. Cervical radiculopathy/myelopathy 2. Left supraspinatus tear 3. Left subacromial impingement 4. Left adhesive capsulitis 4. Left brachial plexopathy TESTS AND RESULTS Left Shoulder MRI -No supraspinatus tear -Subtle superior/posterior labral tear -Trace biceps tenosynovitis Cervical Spine MRI -Left paracentral disc herniation causing moderate spinal canal stenosis with compression of spinal cord and myelomacia at C5-6 level. -Moderate to severe foraminal stenosis, worse on the left at C5/6. Left Brachial Plexus MRI -No abnormality Upper Extremities EMG/NCS -Left primarily demyelinating median nerve mononeuropathy across the wrist. -Denervation and re-innervation at the level of the left triceps brachii muscle without abnormalities in other C6 or C7 innervated muscles or radial innervated muscles to assist with innervation suggestive of cervical radiculopathy FINAL WORKING DIAGNOSIS -Left cervical radiculopathy with myelopathic features TREATMENT AND OUTCOMES -Referral to Neurosurgery for potential surgical decompression in setting of cervical myelopathic findings. - Initiated physical therapy focusing on McKenzie based program with spine stabilization.

Finger Pain In A Professional Dog Groomer

HISTORY: A 36-year-old right-handed female professional dog groomer with past medical history of PCOS, presents with a chief complaint of left hand digit 3 and 4 fingertip pain. She reports progressive discomfort for the past 10 months, worsened with tactile touch especially during work, and mildly improves with rest. Describes the pain as sharp electrical sensations rated 10/10 on pain scale, sensitive to cold weather. Outside facility workup included normal hand x-rays, cervical x-rays and a hand MRI. Electrodiagnostic/nerve conduction studies demonstrated mild carpal tunnel syndrome on the left without radiculopathy, for which she has tried a neutral wrist splint without improvement. She has been seen by her PCP, rheumatology, neurology, endocrinology, and orthopedic surgery, all without a confirmatory diagnosis. Her pain is now debilitating and thus she presents to Stanford for a 6th opinion. EXAM: On inspection no swelling or discoloration. Severe tenderness with light touch of digit 3 at the eponychial fold, ulnar side. Limited active and passive digit 3 DIP flexion due to pain. Sensation decreased in dorsal digital median nerve branch digits 3 and 4. Remaining strength and sensation in the hand intact. Phalen’s test at the wrist positive while tinel’s was negative. Spurling’s negative. DIFFERENTIAL: 1. Median or Palmar Digital Branch Mononeuropathy. 2. C7 Radiculopathy 3. Digital Collateral Ligament Injury 4. Tumor 5. Complex Regional Pain Syndrome 6. Mallet Finger 7. Raynaud’s Phenomenon RESULTS: Point-of-care ultrasound significant for digit 3 solitary hypoechoic lesion with clear boundaries and regular shape, and internal abundant hyperemia. Finger MRI showed 4 x 3 x 3 mm circumscribed T1 hypointense T2 hyperintense, enhancing lesion at dorsal aspect of the third distal phalanx. DIAGNOSIS: Glomus Tumor OUTCOME: Initiation of gabapentin, lidocaine cream for symptomatic relief and referral to orthopedics for definitive treatment with plans for left middle finger glomus tumor excision. The patient is currently pending surgery at the time of this submission, additional follow-up to be presented.

Blocking CTGF/CCN2 reverses neural fibrosis and sensorimotor declines in a rat model of overuse-induced median mononeuropathy.

Encapsulation of median nerves is a hallmark of overuse‐induced median mononeuropathy and contributes to functional declines. We tested if an antibody against CTGF/CCN2 (termed FG‐3019 or Pamrevlumab) reduces established neural fibrosis and sensorimotor declines in a clinically relevant rodent model of overuse in which median mononeuropathy develops. Young adult female rats performed a high repetition high force (HRHF) lever‐pulling task for 18 weeks. Rats were then euthanised at 18 weeks (HRHF untreated), or rested and systemically treated for 6 weeks with either an anti‐CCN2 monoclonal antibody (HRHF‐Rest/FG‐3019) or IgG (HRHF‐Rest/IgG), with results compared with nontask control rats. Neuropathology was evident in HRHF‐untreated and HRHF‐Rest/IgG rats as increased perineural collagen deposition and degraded myelin basic protein (dMBP) in median nerves, and increased substance P in lower cervical dorsal root ganglia (DRG), compared with controls. Both groups showed functional declines, specifically, decreased sensory conduction velocity in median nerves, noxious cold temperature hypersensitivity, and grip strength declines, compared with controls. There were also increases of ATF3‐immunopositive nuclei in ventral horn neurons in HRHF‐untreated rats, compared with controls (which showed none). FG‐3019‐treated rats showed no increase above control levels of perineural collagen or dMBP in median nerves, Substance P in lower cervical DRGs, or ATF3‐immunopositive nuclei in ventral horns, and similar median nerve conduction velocities and thermal sensitivity, compared with controls. We hypothesize that neural fibrotic processes underpin the sensorimotor declines by compressing or impeding median nerves during movement, and that inhibiting fibrosis using an anti‐CCN2 treatment reverses these effects.

Effective self-stretching of carpal ligament for the treatment of carpal tunnel syndrome: A double-blinded randomized controlled study

IntroductionCarpal tunnel syndrome (CTS) is the most common nerve entrapment syndrome worldwide. There are limited studies on the effectiveness of carpal ligament stretching on symptomatic and electrophysiologic outcomes. Purpose of the StudyThe purpose of this study was to evaluate the effect of self-myofascial stretching of the carpal ligament on symptom outcomes and nerve conduction findings in persons with CTS. Study DesignThis is a prospective, double-blinded, randomized, placebo-controlled trial. MethodsEighty-three participants diagnosed with median mononeuropathy across the wrist by nerve conduction study were randomized 1:1 to sham treatment or self-carpal ligament stretching. Participants were instructed to perform the self-treatment four times a day for six weeks. Seventeen participants in the sham treatment group and 19 participants in the carpal ligament stretching group completed the study. Pre- and post-treatment outcome measures included subjective complaints, strength, nerve conduction findings, and functional scores. ResultsGroups were balanced on age, sex, hand dominance, symptom duration, length of treatment, presence of nocturnal symptoms, and compliance with treatment. Even though the ANOVA analyses were inconclusive about group differences, explorative post hoc analyses revealed significant improvements in numbness (P = .011, Cohen's d = .53), tingling (P = .007, Cohen's d = .60), pinch strength (P = .007, Cohen's d = −.58), and symptom severity scale (P = .007, Cohen's d = .69) for the treatment group only. ConclusionsThe myofascial stretching of the carpal ligament showed statistically significant symptom improvement in persons with CTS. Larger comparative studies that include other modalities such as splinting should be performed to confirm the effectiveness of this treatment option.

Peripheral neuropathies in rheumatic diseases: More diverse and frequent than expected. A cross-sectional study.

Peripheral neuropathies (PN) are heterogeneous nerve disorders; frequently rheumatic patients have neuropathic symptoms. In some rheumatic diseases (RD) PN are secondary to nerve compression while others are related to metabolic abnormalities, inflammation or vasculitis. Our aim was to explore the frequency of neuropathic symptoms with three neuropathy questionnaires (NQ) and nerve conduction studies (NCS) in RD. This is a cross-sectional study in patients with any RD attending for the first time to a rheumatology outpatient clinic. We included all patients who accepted to participate and who answered three NQ and received a physical evaluation. Twenty patients were randomly selected to perform NCS and 10 healthy subjects were included as controls. The topographic diagnoses were: mononeuropathy, multiplex mononeuropathy, and/or polyneuropathy. descriptive statistics (mean, median, standard deviation, interquartile range and frequency, odds ratios and Pearson correlation test). One hundred patients and 10 healthy subjects were included. Sixty-nine were female, mean age 40.6±15.7years. Rheumatic diagnoses were: systemic lupus erythematosus (26%), rheumatoid arthritis (16%), gout (14%), and osteoarthritis (11%). Fifty-two patients had neuropathic signs during physical examination and 67% had positive questionnaires with variable scores among several RD. Abnormal NCS was reported in 14 patients (70%): 6 (42.8%) median nerve mononeuropathies, 4 (28.5%) multiplex mononeuropathies and 4 (28.5%) polyneuropathies. None of the healthy subjects had neuropathy (NQ, physical evaluation, or NCS). Risk of being NCS positive is higher when the patients were NQ positive. PN has variable distribution and high frequency in patients with RD; NQ+ increases the risk of presenting NCS+ for PN.

Idiopathic Median Mononeuropathy in a Previously Healthy Child: The Usefulness of Magnetic Resonance Imaging in Making the Diagnosis

Idiopathic Median Mononeuropathy in a Previously Healthy Child: The Usefulness of Magnetic Resonance Imaging in Making the Diagnosis

A telemedicine approach to carpal tunnel syndrome: is it useful? A 2 year retrospective analysis in the province of Venice

In 2016 we started to perform electrodiagnostic studies (EDX) for suspected carpal tunnel syndrome (CTS) in our district, conducted independently by the technical staff (complete median e ulnar sensorimotor conduction study of median e ulnar nerves, with proximal stimulation and F waves), according to general practitioner request: EDX reports are performed within 7 days by neurologists through the central station in the main hospital, indicating to repeat EDX when negative. The study analyzes if CTS telemedicine approach is useful. We retrospectively collected data from 314 EDX studies carried out from March 2016, enumerate CTS positive patients, side, grading and time of onset. Data were collected from 314 patients, 81 males and 233 females, mean age 60 ± 16 years, 289 with CTS confirmed, 198 monolateral and 91 bilateral (92% positive exams). 122 patients had mild, 142 medium and 25 severe CTS. 25 patients had negative EDX: 6 had ulnar mononeuropathy, 4 had suspected radiculopathy, 1 had motor median mononeuropathy and 14 no other suspected diseases. 21 patients had coherent symptoms but negative EDX, while only 12 on 314 requests are incongruous Telemedicine provide a good alternative for diagnosing CTS. Few and contradictory data are available regarding intraoperative seizures (IOS) during surgery for Low Grade Gliomas (LGGs). Aim of this study was to evaluate the occurrence of IOS in regard to pre-operative clinical data, tumor molecular characteristics and electrocorticographic patterns. We performed a retrospective analysis of 155 patients affected by LGGs and tumor-related epilepsy, who underwent surgery in our Department, between 2007 and 2017. Pre-operative seizures frequency was as follows: 59% monthly, 34% weekly and 11% daily. 73% of patients were operated on through awake surgery. IOS occurred in 39 patients: in 9 patients only electrographic seizures occurred while in 13 patients seizures were cognitive, sensory, autonomic or emotional, thus recognizable only by means of electrocorticography (ECoG). Nineteen seizures were induced by brain mapping. Patients with ECoG epileptiform inter-critical patterns and IDH1/2 mutated tumors or oligodendrogliomas were more likely to develop IOS (p

Prevalence of carpal tunnel syndrome presenting with symptoms in an ulnar nerve distribution: A prospective study.

Patients presenting with symptoms of pain/paresthesias primarily in an ulnar nerve distribution may be noted to have exclusive median mononeuropathy at the wrist on subsequent electrodiagnostic testing. There has been limited research looking at the prevalence of this clinical presentation. A cohort of adults were surveyed to assess for severity and localization of hand symptoms using the Katz hand diagram and Boston Carpal Tunnel Questionnaire Symptoms Severity Scale. Thirty volunteers met our case definition for ulnar neuropathy and underwent a standardized physical examination, electrodiagnostic testing, and nerve ultrasound. Eleven of 30 subjects (37%) were found to have exclusive median mononeuropathy at the wrist. Carpal tunnel syndrome should remain high on the differential for patients presenting with symptoms of pain/paresthesias primarily in an ulnar nerve distribution. Muscle Nerve 59:60-63, 2019.

Peripheral nerve injuries in the pediatric population: a review of the literature. Part II: entrapment neuropathies.

Entrapment neuropathies are infrequent in children, and therefore remain unrecognized. The incidence of radial, median, and cubital mononeuropathies are all similar. Despite the rarity of such cases, extensive, albeit scattered, literature has accumulated concerning entrapment neuropathies in children. To the literature concerning entrapment neuropathies in children. A systematic review of the existing literature has been made. The management of chronic pediatric pain is very important in such patients to prevent youths from experiencing prolonged absences from school, sports, or other productive activities, and limit the psychological burden of chronic disease. Nonsurgical treatment of both cubital and carpal tunnel syndromes has been disappointing in pediatric patients, with only limited success; and, to date, there is no clear explanation for the outcome differences generated by nonsurgical management between adults and youths. Simple decompression of the ulnar nerve at the elbow also has much higher rates of failure in children than in adults. The presence of an entrapment neuropathy (specially carpal tunnel syndrome) in a pediatric-age patient should alert medical care providers to the potential of some underlying genetic condition or syndrome.

Clinical and mutational spectrum of Japanese patients with recessive variants in SH3TC2.

SH3TC2, known as the causative gene of autosomal recessive demyelinating Charcot-Marie-Tooth type 4C (CMT4C), was also found linked to a mild mononeuropathy of the median nerve with an autosomal dominant inheritance pattern. Using DNA microarray, Illumina MiSeq, and Ion proton, we carried out gene panel sequencing among 1483 Japanese CMT patients, containing 397 patients with demyelinating CMT. From seven patients with demyelinating CMT, we identified eight recessive variants in the SH3TC2 gene, consisting of five novel (pathogenic/likely pathogenic) and three reported variants. Additionally, from two patients with axonal CMT, we detected a reported recessive variant, p.Arg77Trp, which was herein reclassified as variant with unknown significance. Of the seven CMT4C patients (six females and one male), 2/7 patients developed symptoms at their first decade, and 5/7 patients lost their ambulation around age 50. Scoliosis was observed from more than half (4/7) of these patients, whereas hearing loss is the most common symptom of central nervous system (6/7). No median nerve mononeuropathy was recorded from their family members. We identified recessive variants in SH3TC2 from 1.76% of demyelinating CMT patients. An uncommon gender difference was recognized and the wild spectrum of these variants suggests mutational diversity of SH3TC2 in Japan.

Diagnostic Value of the Second Lumbrical-Interosseous Distal Motor Latency Comparison Test in Severe Carpal Tunnel Syndrome

ObjectiveTo examine the usefulness of the second lumbrical-interosseous (2L-INT) distal motor latency (DML) comparison test in localizing median neuropathy to the wrist in patients with absent median sensory and motor response in routine nerve conduction studies.MethodsElectrodiagnostic results from 1,705 hands of patients with carpal tunnel syndrome (CTS) symptoms were reviewed retrospectively. All subjects were evaluated using routine nerve conduction studies: median sensory conduction recorded from digits 1 to 4, motor conduction from the abductor pollicis brevis muscle, and the 2L-INT DML comparison test.ResultsFour hundred and one hands from a total of 1,705 were classified as having severe CTS. Among the severe CTS group, 56 hands (14.0%) showed absent median sensory and motor response in a routine nerve conduction study, and, of those hands, 42 (75.0%) showed an abnormal 2L-INT response.ConclusionThe 2L-INT DML comparison test proved to be a valuable electrodiagnostic technique in localizing median mononeuropathy at the wrist, even in the most severe CTS patients.

Longitudinal Analysis of Median Nerve Perfusion Using Spectral Doppler in a Working Animal Model

Carpal tunnel syndrome (CTS) is a form of median mononeuropathy (MMN) of the wrist that has become the most common nerve entrapment syndrome of the upper limbs. During the acute phase of CTS, the median nerve becomes hyperemic and enlarged as it begins to be compressed by the transverse carpal ligament; however, continual compression ultimately leads to median nerve ischemia. The objective of this study was to longitudinally quantify the amount of perfusion of the median nerve using spectral Doppler in a working animal model, as the cohort prospectively increased their risk of MMN through a repetitive pinching task. The results of the study provided low-level evidence that the use of spectral Doppler to accurately detect longitudinal changes in vascularity within the median nerve may be diagnostically inadequate. As the subjects in the study moved through the working and nonworking stages of study, spectral Doppler alone proved to lack the level of sensitivity needed to detect physiologic changes within the nerve. This outcome, although inconclusive when it comes to detecting changes in median nerve vascularity, does suggest the need for this method to be analyzed in conjunction with other sonographic features and provocative testing.

Use of Contrast‐Enhanced Sonography to Investigate Intraneural Vascularity in a Cohort of Macaca fascicularis With Suspected Median Mononeuropathy

The purpose of this study was to provide clinical evidence of the use of contrast-enhanced sonography in detecting and quantifying changes in intraneural vascularity due to median mononeuropathy. Five Macaca fascicularis monkeys were exposed to 20 weeks of repetitive work to increase their risk of developing median mononeuropathy. Contrast-enhanced sonograms were obtained in 30-second increments for 7 minutes while a contrast agent was being delivered. Data were collected immediately at the conclusion of the 20-week work exposure and then again during a recovery phase approximately 3 months after the completion of work. Quantitative analysis and trend graphs were used to analyze median nerve perfusion intensity. This study also compared the use of both manual counting of pixels and semiautomatic measurement using specialized software. Based on the average data, maximum intensity values were identified as the best indicators of nerve hyperemia. Paired t tests demonstrated significantly higher maximum intensities in the working stage for 4 of the 5 subjects (P < .01). This study provides preliminary evidence that (1) in a controlled exposure model, a change in intraneural vascularity of the median nerve between working and recovery can be observed; (2) this vascular change can be measured using an objective technique that quantifies the intensity of vascularity; and (3) contrast-enhanced sonography may improve the ability to reliably capture and measure low-flow microvascularity.