Role of Sonography in Surgical Decision Making for Iatrogenic Spinal Accessory Nerve Injuries

The spinal accessory nerve (SAN) is susceptible to iatrogenic injury in the posterior cervical triangle. Early diagnosis and management of suspected SAN transection injuries are crucial in the restoration of shoulder stability and function. Although neurologic examination and electrodiagnostic testing can assess SAN function, they cannot assess nerve continuity. We report the use of sonography to prospectively evaluate the SAN in 6 patients with suspected iatrogenic SAN injury. Sonography directly visualized SAN transection in 4 cases, whereas sonographic findings were reported as “probable” transection in the fifth case and was nondiagnostic in the sixth case in the setting of extensive scarring.     

Sonography of Common Peripheral Nerve Disorders With Clinical Correlation

Sonography is now considered an effective method to evaluate peripheral nerves. Low cost, high resolution, the ability to image an entire limb in a short time, and dynamic assessment are several of the positive attributes of sonography. This article will review the normal appearance of peripheral nerves as shown with sonography. In addition, the most common applications for sonography of the peripheral nerves will be reviewed, which include entrapment neuropathies, intraneural ganglion cyst, nerve trauma, and peripheral nerve sheath tumors. Clinical information related to nerve disorders is also included, as it provides valuable information that can be obtained during sonographic examinations, increasing diagnostic accuracy.     

Sonography of peripheral nerves: technique,anatomy, and pathology

Sonography provides a unique method for evaluating peripheral nerves because of its high spatial resolution, its ability to follow structures over long distances in a limb, and its dynamic nature that allows movement of patient and transducer. When combined with the wide availability and relatively low cost, sonography is an excellent modality for peripheral nerve assessment. The authors review the techniques used in assessment of peripheral nerves, the relevant anatomy, and common pathologic processes.     

周围神经创伤性神经瘤的超声诊断

目的 探讨周围神经创伤性神经瘤的声像图特征及其诊断价值.方法 回顾性分析38例经手术证实的周围神经创伤性神经瘤的超声表现.结果 38例中2例神经不完全损伤性神经瘤超声未检出,1例神经不完全损伤性神经瘤超声误诊为神经鞘瘤.神经不完全损伤性神经瘤和完全离断性神经瘤的超声检查结果与手术结果的符合率分别为82.4%和100%.38例神经瘤均表现为低回声,其中33例呈梭状,5例呈驼峰状.结论 超声可清楚地显示创伤性神经瘤的部位、大小及与周围组织的关系,对临床的诊断治疗有重要的指导价值.     

Metallothionein deficiency in the injured peripheral nerves of complex regional pain syndrome as revealed by proteomics

Complex regional pain syndrome (CRPS) is characterized by persistent and severe pain after trauma or surgery; however, its molecular mechanisms in the peripheral nervous system are poorly understood. Using proteomics, we investigated whether injured peripheral nerves of CRPS patients have altered protein profiles compared with control nerves. We obtained nerve samples from 3 patients with CRPS-2 who underwent resection of part of an injured peripheral nerve. Sural nerves from fresh cadavers with no history of trauma or neuropathic pain served as controls. Proteomic analysis showed that the number and functional distribution of proteins expressed in CRPS and control nerves was similar. Interestingly, metallothionein was absent in the injured nerves of CRPS-2, although it was readily detected in control nerves. Western blotting further confirmed the absence of metallothionein in CRPS-2 nerves, and immunohistochemistry corroborated the deficiency of metallothionein expression in injured nerves from 5 of 5 CRPS patients and 2 of 2 patients with painful neuromas. In contrast, all control nerves, including 5 sural nerves from fresh cadavers and 41 nerves obtained from surgically resected tumors, expressed MT. Furthermore, expression of S100 as a marker for Schwann cells, and neurofilament M as a marker of axons was comparable in both CRPS-2 and controls. Metallothioneins are zinc-binding proteins that are probably involved in protection against injury and subsequent regeneration after CNS damage. Their absence from the injured peripheral nerves of patients with CRPS-2 suggests a potential pathogenic role in generating pain in the damaged peripheral nerves.     

Role of Ulnar Nerve Sonography in Leprosy Neuropathy With Electrophysiologic Correlation

Objective. The purpose of this study was to evaluate the diagnostic usefulness of ulnar nerve sonography in leprosy neuropathy with electrophysiologic correlation. Methods. Twenty‐one consecutive patients with leprosy (12 men and 9 women; mean age ± SD, 47.7 ± 17.2 years) and 20 control participants (14 men and 6 women; mean age, 46.5 ± 16.2 years) were evaluated with sonography. Leprosy diagnosis was established on the basis of clinical, bacteriologic, and histopathologic criteria. The reference standard for ulnar neuropathy in this study was clinical symptoms in patients with proven leprosy. The sonographic cross‐sectional areas (CSAs) of the ulnar nerve in 3 different regions were obtained. Statistical analyses included Student t tests and receiver operating characteristic curve analysis. Results. The CSAs of the ulnar nerve were significantly larger in the leprosy group than the control group for all regions (P < .01). Sonographic abnormalities in leprosy nerves included focal thickening (90.5%), hypoechoic areas (81%), loss of the fascicular pattern (33.3%), and focal hyperechoic areas (4.7%). Receiver operating characteristic curve analysis showed that a maximum CSA cutoff value of 9.8 mm² was the best discriminator (sensitivity, 0.91; specificity, 0.90). Three patients with normal electrophysiologic findings had abnormal sonographic findings. Two patients had normal sonographic findings, of which 1 had abnormal electrophysiologic findings, and the other refused electrophysiologic testing. Conclusions. Sonography and electrophysiology were complementary for identifying ulnar nerve neuropathy in patients with leprosy, with clinical symptoms as the reference standard. This reinforces the role of sonography in the investigation of leprosy ulnar neuropathy.     

Posttraumatic Painful Hip

Objective. Nondisplaced hip fractures may be radiographically occult and require magnetic resonance imaging (MRI) or bone scintigraphy for diagnosis. Both examinations are expensive and are not readily available in many hospitals. Our objective was to evaluate sonography as a screening tool for occult hip fractures in posttraumatic painful hips in elderly patients. Methods. We prospectively evaluated 30 patients (mean age, 73 years), who were admitted for painful hips after having low‐energy trauma with nondiagnostic hip radiographs. After inclusion, patients underwent sonography of both hips for signs of injury. After completion of the sonographic examination and analysis of the results, patients underwent MRI of both hips. The sonographic findings were compared with the MRI findings, which served as the reference standard for accurate detection of a hip fracture. Results. Ten hip fractures were diagnosed by MRI. Sonography showed trauma‐related changes in all of those patients and in 7 additional patients, 3 of whom had pubic fractures. Sonography correctly identified 13 patients without hip fractures. The sensitivity of sonography was found to be 100%, whereas the specificity for hip fractures was 65%. Conclusions. Sonography for posttraumatic hip pain with negative radiographic findings did not result in a single missed hip fracture. Therefore, sonography may serve as an effective screening tool, mandating MRI only for cases with positive findings, whereas patients with negative sonographic findings need no further investigation. Sonography may therefore be very useful in hospitals around the world, where MRI may not be readily affordable or available.     

Immunolocalization of SNS/PN3 and NaN/SNS2 sodium channels in human pain states

The tetrodotoxin-resistant (TTX-R) voltage-gated sodium channel SNS/PN3 and the newly discovered NaN/SNS2 are expressed in sensory neurones, particularly in nociceptors. Using specific antibodies, we have studied, for the first time in humans, the presence of SNS/PN3 and NaN/SNS2 in peripheral nerves, including tissues from patients with chronic neurogenic pain. In brachial plexus injury patients, there was an acute decrease of SNS/PN3- and NaN/SNS2-like immunoreactivity in sensory cell bodies of cervical dorsal root ganglia (DRG) whose central axons had been avulsed from spinal cord, with gradual return of the immunoreactivity to control levels over months. In contrast, there was increased intensity of immunoreactivity to both channels in some peripheral nerve fibers just proximal to the site of injury in brachial plexus trunks, and in neuromas. These findings suggest that the expression of these sodium channels in neuronal cell bodies is reduced after spinal cord root avulsion injury in man, but that pre-synthesized channel proteins may undergo translocation with accumulation at sites of nerve injury, as in animal models of peripheral axotomy. The latter may contribute to positive symptoms, as our patients all showed a positive Tinel's sign. Nerve terminals in distal limb neuromas and skin from patients with chronic local hyperalgesia and allodynia all showed marked increases of SNS/PN3-immunoreactive fibers, but little or no NaN/SNS2-immunoreactivity, suggesting that the former may be related to the persistent hypersensitive state. Axonal immunoreactivity to both channels was similar to control nerves in sural nerve biopsies in a selection of neuropathies, irrespective of nerve inflammation, demyelination or spontaneous pain, including a patient with congenital insensitivity to pain. Our studies suggest that the best target for SNS/PN3 blocking agents is likely to be chronic local hypersensitivity.     

High resolution ultrasound in subclinical diabetic neuropathy: A potential screening tool

IntroductionDetection of subclinical neuropathy can aid in triage, timely intervention and dedicated care to reduce disease progression and morbidity. High resolution sonography has emerged as a promising technique for evaluation of peripheral nerves. The aim of the present study was to assess the utility of high resolution sonography in screening diabetic patients for subclinical neuropathy.MethodsA total of 70 adult patients with type 2 diabetes mellitus and 30 controls were enrolled; those with clinical features of neuropathy constituted the diabetic polyneuropathy group and those without symptoms/normal nerve conduction the non-diabetic polyneuropathy group. After institutional ethical committee approval and informed consent, high resolution sonography was performed by two musculoskeletal radiologists. Nerves studied were median (elbow and wrist), ulnar (cubital tunnel and Guyon’s canal), common peroneal (fibular head) and posterior tibial nerve (medial malleolus).The size (cross sectional area), shape, echogenicity and morphology of nerve were assessed and compared between the groups.ResultsThe mean cross sectional area of all nerves was significantly higher both in diabetic polyneuropathy and non-diabetic polyneuropathy group compared to controls (p value < .001). Common peroneal nerve cross sectional area of 4.5 mm² had the highest sensitivity (93%) and specificity (86%) for detecting nerve changes in the non-diabetic polyneuropathy group. The nerves were more rounded, hypoechoic and had an altered morphology in both study groups.ConclusionPresence of sonographic nerve changes in asymptomatic diabetics depicted that morphological alterations in nerves precede clinical symptoms. High resolution sonography detected nerve changes with a good accuracy, and thus, can be a potential screening tool for detection of subclinical diabetic polyneuropathy.     

Deferoxamine-induced dysplasia of the knee: sonographic features and diagnostic performance compared with magnetic resonance imaging.

OBJECTIVE: To evaluate the features and diagnostic performance of sonography in the assessment of deferoxamine-induced dysplasia of the knee. METHODS: The left knees of 32 patients with thalassemia who were receiving regular blood transfusions and chelation therapy were studied with sonography for signs of deferoxamine-induced bone dysplasia. Abnormal physeal and metaphyseal changes detected on sonography included notching at the metaphyseal corner, a blurred or irregular peripheral juxtaphyseal metaphyseal contour, and widening of the peripheral juxtaphyseal metaphyseal echogenic interface. The accuracy of sonography in diagnosing dysplasia was evaluated by using magnetic resonance imaging as the standard of reference. RESULTS: There were 14 true-positive findings, 10 true-negative findings, 7 false-negative findings, and 1 false-positive sonographic diagnosis of dysplasia, giving 67% sensitivity, 91% specificity, a 93% positive predictive value, and a 59% negative predictive value. CONCLUSION: Sonography was specific but only moderately sensitive in the diagnosis of deferoxamine-induced dysplasia at the knee when compared with magnetic resonance imaging.     

Sonographic detection of diffuse peripheral nerve hypertrophy in chronic inflammatory demyelinating polyradiculoneuropathy

Chronic inflammatory demyelinating polyradiculoneuropathy is an autoimmune disease characterized by recurrent demyelination and remyelination with resultant thickening of the peripheral nerves. We report a case in which sonography was instrumental in demonstrating diffuse peripheral nerve hypertrophy. On sonography, both brachial plexuses were found to be diffusely hypertrophic and hypoechoic. Similar findings were noted for the median, sciatic, and femoral nerves. The brachial plexus findings were confirmed by MRI.     

High-resolution sonography of lower extremity peripheral nerves: anatomic correlation and spectrum of disease.

OBJECTIVE: The value of sonography for the diagnosis of diseases of the peripheral nervous system is only little known. This image presentation is intended to raise the awareness of sonographers and clinicians of the potential of sonography by giving an anatomic-sonographic correlation of lower extremity peripheral nerves and an overview of commonly encountered diseases. METHODS: On 2 lower extremity cadaver specimens, peripheral nerves were imaged in typical locations such as the tarsal tunnel. During sonography the nerve was injected with blue dye, and thin-slice anatomic sections were obtained at the scan level with a chain saw. In addition, sonographic images of patients with typical diseases are shown. RESULTS: An excellent anatomic-sonographic correlation was obtained, which underlines the feasibility of sonography for imaging of lower extremity peripheral nerves. Reliable results may be obtained with sonography of typical disease processes of lower extremity peripheral nerves. CONCLUSIONS: Recent developments in sonographic technology such as the introduction of high-frequency linear array transducers, compound imaging, and extended field-of-view imaging strongly improve the applicability of transcutaneous sonography for the examination of peripheral nerve disease.     

Assessment of nerve damage in the feet of long-distance runners

To answer the question, "Does long-distance running injure nerves of the feet and legs?" we invited the 25 members of the Rochester Track Club who had run the greatest number of miles in their lifetime to participate in a study that involved neurologic examination, determination of detection thresholds of touch-pressure, vibratory, and cooling sensations of the foot, and evaluation of nerve conduction. None of the runners had clinical symptoms or signs of peripheral neuropathy. Most of them reported having had toe and foot injuries, sometimes associated with short-lived sensory symptoms. A computer-assisted sensory evaluation of the detection threshold for vibratory sensation of the toe revealed slightly, but significantly, higher values in the runners in comparison with age- and sex-matched control subjects. Similarly, small, but statistically significant, differences were also observed for some attributes of nerve conduction in the leg and foot nerves of the runners. These results suggest that long-distance running causes multiple small injuries to the toes and feet, which lead to measurable differences in the detection threshold for vibratory sensation and in nerve conduction but not to overt neuropathy. The trivial subclinical neuropathic deficits we noted are readily offset by the assumed health and recreational benefits of running.     

Chronic pain and sensorimotor deficits following peripheral nerve injury

Following upper limb peripheral nerve transection and surgical repair (PNIr) patients frequently exhibit sensory and motor deficits, but only some develop chronic neuropathic pain. Thus, the sensorimotor outcome of PNIr may be impacted by individual factors. Therefore, our aims were to determine if patients with chronic neuropathic pain (PNI-P) following PNIr (1) are distinguished from patients without pain (PNI-NP) and healthy controls (HCs) by the psychological factors of pain catastrophizing, neuroticism or extraversion, and (2) exhibit more severe sensorimotor deficits than patients who did not develop chronic pain (PNI-NP). Thirty-one patients with complete median and/or ulnar nerve transection (21 PNI-NP, 10 PNI-P) and 21 HCs completed questionnaires to assess pain characteristics, pain catastrophizing, neuroticism and extraversion and underwent sensorimotor evaluation. Nerve conduction studies revealed incomplete sensorimotor peripheral recovery based on abnormal sensory and motor latency and amplitude measures in transected nerves. The patients also had significant deficits of sensory function (two-point discrimination and vibration, touch, and warmth detection), sensorimotor integration, and fine motor dexterity. Compared to PNI-NP patients, PNI-P patients had higher vibration detection thresholds, performed worse on sensory-motor integration tasks, had greater motor impairment, and showed more impaired nerve conduction. Furthermore, PNI-P patients had reduced cold pain tolerance, elevated pain intensity and unpleasantness during the cold pressor test, and they scored higher on neuroticism and pain-catastrophizing scales. These data demonstrate that chronic neuropathic pain following PNIr is associated with impaired nerve regeneration, profound sensorimotor deficits and a different psychological profile that may be predictive of poor recovery after injury.     

Acute Abdomen in Pregnancy

Objective. The purpose of this presentation is to review the role of sonography in evaluation of acute abdomen during pregnancy. Methods. Illustrative cases were collected from gravid patients who presented with signs and symptoms suspicious for acute abdomen and subsequently underwent sonography. Results. This presentation shows sonographic findings of various maternal complications that can present with acute abdominal pain in pregnant patients. Conclusions. Sonography remains the first line of imaging in pregnant patients presenting with acute abdomen. Patient triage or additional imaging may be obtained on the basis of the sonographic findings.     

Principles of neurologic localization

Organic and nonorganic neurologic conditions can be differentiated by determining whether the symptoms can or cannot be feigned and whether the symptoms make neuroanatomic sense. For localization of organic disease, lower motor neuron signs and dermatome defects suggest peripheral nerves; sensory dissociation points to the spinal cord, and a cranial nerve deficit with a contralateral extremity deficit suggests a brainstem etiology. Higher level, organized dysfunction points to the cerebrum; ataxia during intentional movements indicates cerebellar involvement, and sudden, unintended movements suggest basal ganglia disorders.     

The prevalence of symptomatic, diabetic neuropathy in an insulin-treated population

The prevalence of symptomatic sensorimotor polyneuropathy has been determined in a population of 382 insulin-treated diabetic subjects aged 15-59 yr. Forty-one subjects (10.7%) were found to have diabetic neuropathy, according to strict diagnostic criteria that required the presence of symptoms and signs of nerve dysfunction in the absence of peripheral vascular disease. There was a significant correlation between glycosylated hemoglobin levels and motor conduction velocity in the median and peroneal nerves in all subjects. This finding further emphasizes the importance of metabolic factors related to hyperglycemia in the impaired nerve function seen in diabetic patients.     

应用几丁糖-胶原-二丙酸倍他米松缓释复合膜提高周围神经修复疗效的实验研究

目的:评价周围神经损伤后,神经吻合口局部应用几丁糖-胶原-二丙酸倍他米松缓释复合膜抑制疤痕增生、促进神经再生、提高神经功能恢复的作用.方法:成年雄性SD大鼠36只,胫神经切断术后随机分为3组,每组12只,A组仅给予单纯缝合,B组给予单纯缝合+吻合口包裹聚-DL-乳酸膜,C组给予单纯缝合+吻合口包裹几丁糖-胶原-二丙酸倍...     

High prevalence of vasomotor reflex impairment in newly diagnosed leprosy patients

BACKGROUND: Initial nerve damage in leprosy occurs in small myelinated and unmyelinated nerve fibers. Early detection of leprosy in the peripheral nervous system is challenging as extensive nerve damage may take place before clinical signs of leprosy become apparent. PATIENTS AND METHODS: In order to determine the prevalence of, and factors associated with, peripheral autonomic nerve dysfunction in newly diagnosed leprosy patients, 76 Brazilian patients were evaluated prior to treatment. Skin vasomotor reflex was tested by means of laser Doppler velocimetry. Blood perfusion and reflex vasoconstriction following an inspiratory gasp were registered on the second and fifth fingers. RESULTS: Vasomotor reflex was impaired in at least one finger in 33/76 (43%) patients. The fifth fingers were more frequently impaired and suffered more frequent bilateral alterations than the second fingers. Multivariate regression analysis showed that leprosy reaction (adjusted odds ratio = 8.11, 95% confidence interval: 1.4-48.2) was associated with overall impaired vasomotor reflex (average of the four fingers). In addition, palmar erythrocyanosis and an abnormal upper limb sensory score were associated with vasomotor reflex impairment in the second fingers, whereas anti-phenolic glycolipid-I antibodies, ulnar somatic neuropathy and a low finger skin temperature were associated with impairment in the fifth fingers. CONCLUSIONS: A high prevalence of peripheral autonomic dysfunction as measured by laser Doppler velocimetry was observed in newly diagnosed leprosy patients, which is clinically evident late in the disease. Autonomic nerve lesion was more frequent than somatic lesions and was strongly related to the immune-inflammatory reaction against M. leprae.     

Peripheral nerve tumors of the hand: Clinical features,diagnosis, and treatment

The majority of the tumors arising from the peripheral nerves of the hand are relatively benign. However, a tumor diagnosed as malignant peripheral nerve sheath tumor (MPNST) has destructive consequences. Clinical signs and symptoms are usually caused by direct and indirect effects of the tumor, such as nerve invasion or compression and infiltration of surrounding tissues. Definitive diagnosis is made by tumor biopsy. Complete surgical removal with maximum reservation of residual neurologic function is the most appropriate intervention for most symptomatic benign peripheral nerve tumors (PNTs) of the hand; however, MPNSTs require surgical resection with a sufficiently wide margin or even amputation to improve prognosis. In this article, we review the clinical presentation and radiographic features, summarize the evidence for an accurate diagnosis, and discuss the available treatment options for PNTs of the hand.