A Cohort Study on Neuropathic Pain of the Sural Nerve-Can Neurectomy Be Considered a Valid Treatment Option?

BACKGROUND: Sural nerve neuroma is often caused by an injury during prior surgery, for example, osteosynthesis or ligament refixations at ankle level. Different surgical techniques to treat neuroma have been described. Neurectomy of an injured symptomatic sural nerve has been described as a treatment option for neuropathic pain. The aim of this study was to evaluate the outcomes of this technique to operatively treat sural nerve neuroma in our department. METHODS: From 2010 to 2020, a total of 30 consecutive patients with neuropathic pain and suspected neuroma of the sural nerve underwent sural nerve neurectomy. A medical chart review was performed to collect patient-, pain-, and treatment-specific factors. Outcomes were registered. RESULTS: After neurectomy, 22 patients (73.3%) had persisting pain. In logistic regression models evaluating the risk of persisting pain after sural nerve neurectomy, no independent predictor of higher risk of persisting pain could be identified. CONCLUSION: For sural nerve neuromas, neurectomy remains an option as the surgical morbidity is minor, but patients need to be counseled that only a fourth of those undergoing surgery will be pain-free afterward.

Comparison of electrodiagnosis, neurosonography and MR neurography in localization of ulnar neuropathy at the elbow.

INTRODUCTION: In patients with ulnar neuropathy at the elbow (UNE) the precise determination of the site of lesion is important for subsequent differential diagnostic considerations and therapeutic management. Due to a paucity of comparable data, to better define the role of different diagnostic tests, we performed the first prospective study comparing the diagnostic accuracy of short segment nerve stimulation, nerve ultrasonography, MR neurography (MRN), and diffusion tensor imaging (DTI) in patients with UNE. METHODS: UNE was clinically diagnosed in 17 patients with 18 affected elbows. For all 18 affected elbows in patients and 20 elbows in 10 healthy volunteers, measurements of all different diagnostic tests were performed at six anatomical positions across the elbow with measuring points from distal (D4) to proximal (P6) in relation to the medial epicondyle (P0). Additional qualitative assessment regarding structural changes of surrounding nerve anatomy was conducted. RESULTS: The difference between affected arms of patients and healthy control arms were most frequently the largest at measure intervals D2 to P0 and P0 to P2 for electrophysiological testing, or measure points P0 and P2 for all other devices, respectively. At both levels P0 and at P2, T2 contrast-to-noise ratio (CNR) of MRN and mean diffusivity (MD) of DTI-based MRN showed best accuracies. DISCUSSION: This study revealed differences in diagnostic performance of tests concerning a specific location of UNE, with better results for T2 contrast to noise ratio (CNR) in MRN and mean diffusivity of DTI-based MRN. Additional testing with MRN and nerve ultrasonography is recommended to uncover anatomical changes.

[The use of intraoperative fascicle-topographic electromyography in peripheral nerve surgery: review of the literature and clinical experience]. / Die intraoperative Faszikel-topografische Elektromyografie in der peripheren Nervenchirurgie ­ Übersichtsarbeit und Fallbeispiele.

The intraoperative assessment of a pathological nerve segment is crucial in peripheral nerve surgery. Based on different techniques the function of a peripheral nerve is analyzed and either a neurolysis alone or a resection with subsequent nerve reconstruction is performed. Beside the morphological and histological assessment or the use of a nerve stimulator, intraoperative electrophysiology is highly useful. The aim of this diagnostic tool is the recording of objective parameters, documenting the function of peripheral nerves. Intraoperative electroneurography allows the assessment of a nerve action potential over a pathological nerve segment and has been used for decades. In contrast, additional needle electromyography is rarely used even though this technique is characterized by interesting advantages: It is very helpful for the selection of donor fascicles during neurotization surgeries and for the electrophysiological assessment of neuromata in continuity. In the present review, we discuss the value of intraoperative electromyography in the treatment of peripheral nerve trauma as well as peripheral nerve tumors.

[Peripheral nerve reconstruction - diagnostics as a basis for decision-making: report of the Consensus Workshop at the 35th Meeting of the DAM]. / Periphere Nervenrekonstruktion ­ Diagnostik als Grundlage der Entscheidungsfindung ­ Bericht des Consensus-Workshops im Rahmen der 35. Jahrestagung der Deutschsprachigen Gemeinschaft für Mikrochirurgie der peripheren Nerven und Gefäße (DAM).

In the early stage of nerve lesions, the clinical differentiation between neurapraxia, axonotmesis and neurotmesis often presents a big challenge. Especially in the early stage, however, it is crucial to correctly classify the type of damage because this is what essentially determines the therapeutic concept, in particular the surgical approach and, therefore, the prognosis. A precise diagnosis not only requires detailed clinical assessment and medical history taking, but also the use of additional electrophysiological (functional) and/or imaging examinations. Electrophysiological diagnostic tests may provide information ion localization, severity, course, type of damage and incipient or past reinnervation. Preoperative functional diagnostic measures should include neurography, needle electromyography (EMG) and, if needed, evoked potentials (EP), while imaging procedures should include neural sonography and magnetic resonance imaging (MRI). As a complimentary procedure, EMG may also be performed during surgery.

Management of posterior interosseous nerve (PIN) palsies after distal biceps tendon repair using a single incision technique- a conclusive approach to diagnostics and therapy.

Complete distal ruptures of the biceps brachii tendon are rather rare and surgical reinsertion is the gold standard. Recently, one incision approaches for the refixation of the distal biceps tendon have been popularized with the introduction of a single-incision approach employing a trans-radial cortical button fixation. Since the introduction of this fixation technique we have seen more iatrogenic lesions to the posterior interosseous nerve (PIN) after not having seen any PIN lesions with 2 incision biceps refixation techniques over the last 5 years. Several patients with iatrogenic PIN affections after one incision refixation techniques of the distal biceps tendon were referred to our level 1 department of Plastic surgery and hand surgery from different orthopedic surgeons. Over the course of 6 months we saw 5 patients with a similar history. We decided to analyze this problem and propose a course of action to regain function of the PIN innervated muscles as good and fast as possible. If there is a loss of function in the PIN innervated muscles after distal biceps refixation a neurological evaluation including electrophysiology needs to be conducted. An ultrasound assessment of the nerve itself should guide the clinician in the decision between a conservative and a surgical treatment in the early postoperative phase. If surgical exploration is warranted intraoperative neurography should be the basis on which ground (partial) grafting or solely neurolysis is performed. Postoperatively all patients need to follow a rehabilitation protocol to help with nerve regeneration and regaining of motor function.

Consistent Device Simulation Model Describing Perovskite Solar Cells in Steady-State, Transient, and Frequency Domain.

A variety of experiments on vacuum-deposited methylammonium lead iodide perovskite solar cells are presented, including JV curves with different scan rates, light intensity-dependent open-circuit voltage, impedance spectra, intensity-modulated photocurrent spectra, transient photocurrents, and transient voltage step responses. All these experimental data sets are successfully reproduced by a charge drift-diffusion simulation model incorporating mobile ions and charge traps using a single set of parameters. While previous modeling studies focused on a single experimental technique, we combine steady-state, transient, and frequency-domain simulations and measurements. Our study is an important step toward quantitative simulation of perovskite solar cells, leading to a deeper understanding of the physical effects in these materials. The analysis of the transient current upon voltage turn-on in the dark reveals that the charge injection properties of the interfaces are triggered by the accumulation of mobile ionic defects. We show that the current rise of voltage step experiments allow for conclusions about the recombination at the interface. Whether one or two mobile ionic species are used in the model has only a minor influence on the observed effects. A delayed current rise observed upon reversing the bias from +3 to -3 V in the dark cannot be reproduced yet by our drift-diffusion model. We speculate that a reversible chemical reaction of mobile ions with the contact material may be the cause of this effect, thus requiring a future model extension. A parameter variation is performed in order to understand the performance-limiting factors of the device under investigation.

Magnetic Resonance Neurographic and Clinical Long-Term Results After Oberlin's Transfer for Adult Brachial Plexus Injuries.

The primary goal of the surgical treatment of upper brachial plexus injuries is to restore active elbow flexion. Accordingly, Oberlin's transfer has been frequently performed since 1994 and has influenced the development of other nerve transfers. However, the window of opportunity for nerve transfers remains a subject of controversy. The objective of this study was to assess magnetic resonance (MR) neurographic, clinical and electrophysiological long-term results after Oberlin's transfer. For this purpose, we performed a retrospective follow-up study. Six patients with upper brachial plexus or musculocutaneous nerve injuries were assessed; 2 were iatrogenic nerve injuries following shoulder arthroscopy or neurofibroma resection. Direct and indirect signs of neuropathy were objectified with MR neurography. Moreover, clinical and electrodiagnostic follow-up was performed and all patients completed the Disabilities of Arm, Shoulder and Hand score. Mean follow-up was 48 ± 21.9 (range, 20-73) months. Mean age was 40 ± 11.3 years and mean delay to surgery was 9 ± 3.2 months. All patients were satisfied with the functional results and the median Disabilities of Arm, Shoulder and Hand score was 21 (range, 1-57). Biceps strength was improved in 5 patients from Medical Research Council grade M0 to M4-5 and in one patient to M2-3. The donor nerve showed normal motor and sensory action potentials. Follow-up MR neurography demonstrated biceps reinnervation. Taken together, this study reports good long-term results after Oberlin's transfer. MR neurography represents an excellent, noninvasive preoperative planning tool and can be of high value in selected postoperative cases. The combined evaluation of nerves and muscles may help to indicate nerve transfers in delayed cases.

Assessment of median nerve with MR neurography by using diffusion-tensor imaging: normative and pathologic diffusion values.

PURPOSE: To determine normative diffusion values of the median nerve at several anatomic locations in healthy men and women of variable age and to compare these normative values with those in patients with carpal tunnel syndrome. MATERIALS AND METHODS: After ethics board approval and written informed consent were obtained, 45 healthy volunteers (30 women, 15 men) and 15 patients (10 women, five men) were studied. Volunteers were divided into three age groups. Magnetic resonance (MR) neurography with diffusion-tensor imaging (DTI) was performed in all study participants at 3.0 T by using a single-shot echo-planar imaging sequence (repetition time msec/echo time msec, 10 123/40; b=1200 sec/mm2). Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) of the median nerve were determined by two readers at three locations: the levels of the distal radioulnar joint, pisiform bone, and hamate bone. RESULTS: Normative FA and ADC values were calculated for men and women, different age groups, and different anatomic locations. FA and ADC did not differ between men and women (P=.28 and P=.38, respectively). FA decreased and ADC increased when moving from proximal to distal locations (P<.001). FA decreased and ADC increased significantly with age (P<.001). There was a significant difference between healthy volunteers and patients with carpal tunnel syndrome (P<.001 for both FA and ADC). An FA threshold of 0.47 and an ADC threshold of 1.054×10(-3) mm2/sec might be used in the diagnosis of carpal tunnel syndrome. CONCLUSION: Normative diffusion values for MR neurography of the median nerve with DTI depend on the anatomic location and age but not on sex. Age-specific FA and ADC threshold values might be used to diagnose carpal tunnel syndrome.

Increased prevalence of hyperhomocysteinemia in cervical artery dissection causing stroke: a case-control study.

BACKGROUND: Spontaneous cervical artery dissection (sCAD) is a nonatherosclerotic vascular disease of unknown etiology. Mild elevation of total plasma homocysteine (tHcy) levels may be a risk factor for sCAD, but the precise mechanism remains unknown. On the other hand, mild hyperhomocysteinemia is also associated with ischemic stroke related to atherothrombotic or small artery disease. We undertook a case-control study to compare the prevalence of mild hyperhomocysteinemia and tHcy levels between patients with a first ischemic stroke due to sCAD and healthy volunteers, as well as patients with a first ischemic stroke due to atherothrombotic or small artery disease. METHODS: Fasting tHcy levels were determined in 346 consecutive patients with a first ischemic stroke due to sCAD (n = 86) and atherothrombotic or small artery disease (n = 260) within 24 h after the onset of symptoms, and in 100 healthy volunteers. RESULTS: Mild hyperhomocysteinemia was more prevalent in patients with sCAD causing ischemic stroke (n = 33, 38%) than in healthy volunteers (n = 23, 23%; p = 0.034), and less prevalent than in patients with ischemic stroke due to atherothrombotic or small artery disease (n = 149, 57%; p = 0.001). Mean fasting tHcy levels of patients with ischemic stroke caused by sCAD showed a trend to be higher (11.4 +/- 3.8 micromol/l) than those of healthy volunteers (10.2 +/- 3.0 micromol/l, p = 0.61), but were lower than those of patients with stroke due to atherothrombotic or small artery disease (13.6 +/- 6.6 micromol/l, p = 0.002). CONCLUSION: Our results suggest that mild hyperhomocysteinemia may be a risk factor for sCAD causing ischemic stroke, but further studies are needed to identify a possible mechanism. This study confirms the association of hyperhomocysteinemia with ischemic stroke due to atherothrombotic or small artery disease.

Non-convulsive status epilepticus causing focal neurological deficits in CADASIL.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a hereditary small vessel disease caused by mutations of the Notch3 gene. Clinical manifestations include migraine with or without aura, psychiatric disorders, recurrent ischaemic strokes and cognitive decline. Brain MRI shows confluent hyperintense signal alterations involving characteristically the anterior part of the temporal lobes and widespread areas of the deep and periventricular white matter. Focal or generalised seizures represent a rare neurological manifestation in CADASIL with a frequency of 6-10% in two large series. Status epilepticus, however, has not been reported so far. Herein we describe a patient with CADASIL with an acute focal neurological deficit following a prolonged migraine attack. The symptoms were first interpreted as an ischaemic stroke but subsequently diagnosed to be due to a non-convulsive status epilepticus.

Non-convulsive status epilepticus causing focal neurological deficits in CADASIL.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a hereditary small vessel disease caused by mutations of the Notch3 gene. Clinical manifestations include migraine with or without aura, psychiatric disorders, recurrent ischaemic strokes and cognitive decline. Brain MRI shows confluent hyperintense signal alterations involving characteristically the anterior part of the temporal lobes and widespread areas of the deep and periventricular white matter. Focal or generalised seizures represent a rare neurological manifestation in CADASIL with a frequency of 6-10% in two large series.1(,)2 Status epilepticus, however, has not been reported so far. Herein we describe a patient with CADASIL with an acute focal neurological deficit following a prolonged migraine attack. The symptoms were first interpreted as an ischaemic stroke but subsequently diagnosed to be due to a non-convulsive status epilepticus.

Successful treatment of cold-induced neck pain and jaw claudication with revascularization of severe atherosclerotic external carotid artery stenoses.

PURPOSE: To present a patient whose cold-triggered neck pain and jaw claudication remitted after revascularization of severe atherosclerotic stenoses of both external carotid arteries (ECA). CASE REPORT: A 60-year-old vintner presented with jaw claudication and neck pain that increased in severity while he worked in cold temperatures. Angiography showed severe atherosclerotic narrowing of both ECAs. The symptoms disappeared after staged, bilateral percutaneous transluminal angioplasty procedures. However, the pain recurred together with severe bilateral ECA restenoses 6 months later; once again, the pain remitted after redilation. Right-sided neck pain and severe ECA narrowing recurred 5 months later and resolved after carotid endarterectomy. The patient remained asymptomatic and showed no ECA stenosis during a 3-year follow-up. CONCLUSION: Cold-triggered neck pain may be a symptom of atherosclerotic ECA stenoses, and carotid revascularization may be an efficient and safe treatment.