[Nerve injuries and traumatic lesions of the brachial plexus : Imaging diagnostics and therapeutic options]. / Nervenverletzungen und traumatische Läsionen des Plexus brachialis : Bildgebende Diagnostik und therapeutische Optionen.

CLINICAL/METHODICAL ISSUE: Traumatic lesions of peripheral nerves and the brachial plexus are feared complications because they frequently result in severe functional impairment. The prognosis is greatly dependent on the correct early diagnosis and the right choice of treatment regimen. It is important to distinguish between open and closed injuries. STANDARD RADIOLOGICAL METHODS: Initial imaging must critically evaluate or prove nerve continuity and is commonly achieved by high-resolution ultrasonography. During the further course, reactive soft tissue alterations, such as constrictive scarring or neuroma formation can be detected. In the case of deep nerve and plexus injuries this can be excellently achieved by dedicated magnetic resonance neurography (MRN) sequences. METHODICAL INNOVATIONS: The signal yield from brachial plexus imaging can be critically enhanced by the use of dedicated surface coil arrays. Furthermore, diffusion tensor imaging (DTI) may enable the regeneration potential of a nerve lesion to be recognized in the future. PERFORMANCE: Multiple reports have shown that neurosonography enables a precise evaluation of peripheral nerve structures (up to 90% sensitivity and 95% specificity in nerve transection) and that the method can critically impact on therapeutic decision-making in 60%. Currently, there are only few quantitative data on the exact performance of MRN in traumatic nerve lesions; however, individual reports indicate a high level of agreement with intraoperative findings. PRACTICAL RECOMMENDATIONS: In the initial work-up, especially in the case of peripheral, superficial and lesser nerve injuries, neurosonography is the preferred imaging approach to evaluate nerve integrity and the extent of nerve lesions. In the case of extensive nerve injury of proximal nerves and structures of the plexus as well as in the case of suspected root avulsion MRN is the method of choice.

Iatrogenic lesions of peripheral nerves.

Iatrogenic nerve lesions (INLs) are an integral part of peripheral neurology and require dedicated neurologists to manage them. INLs of peripheral nerves are most frequently caused by surgery, immobilization, injections, radiation, or drugs. Early recognition and diagnosis is important not to delay appropriate therapeutic measures and to improve the outcome. Treatment can be causative or symptomatic, conservative, or surgical. Rehabilitative measures play a key role in the conservative treatment, but the point at which an INL requires surgical intervention should not be missed or delayed. This is why INLs require close multiprofessional monitoring and continuous re-evaluation of the therapeutic effect. With increasing number of surgical interventions and increasing number of drugs applied, it is quite likely that the prevalence of INLs will further increase. To provide an optimal management, more studies about the frequency of the various INLs and studies evaluating therapies need to be conducted. Management of INLs can be particularly improved if those confronted with INLs get state-of-the-art education and advanced training about INLs. Management and outcome of INLs can be further improved if the multiprofessional interplay is optimized and adapted to the needs of the patient, the healthcare system, and those responsible for sustaining medical infrastructure.

Surgical treatment of thoracic disc herniations via tailored posterior approaches.

We present clinical findings, radiological characteristics and surgical modalities of various posterior approaches to thoracic disc herniations and report the clinical results in 27 consecutive patients. Within an 8-year period 27 consecutive patients (17 female, 10 male) aged 30-83 years (mean 53 years.) were surgically treated for 28 symptomatic herniated thoracic discs in our department. Six of these lesions (21%) were calcified. In all cases surgery was performed via individually tailored posterior approaches. We evaluated the pre- and postoperative clinical status and the complication rate in a retrospective study. Nearly one half of the lesions (46.4%) were located at the three lowest thoracic segments. Clinical symptoms included back pain or radicular pain (77.8%), altered sensitivity (77.8%), weakness (40.7%), impaired gait (51.9%) or bladder dysfunction (22%). Costotransversectomy was performed in 8 patients, 1 lateral extracavitary approach, 2 foraminotomies, 15 transfacet and/or transpedicular approaches and 2 interlaminar approaches were used for removing the pathologies. After a mean follow-up of 38.6 months (3-100 months), complete normalization or reduction of local pain was recorded in 87% of the patients and of radicular pain in 70% of the cases, increased motor strength could be achieved in 55%, sensitivity improved in 76.2% and improvement of myelopathy was noted in 71.4%. Two patients suffered from postoperative impairment of sensory deficits, which in one case was discrete. The overall recovery rate within the modified JOA score was 39.5%. In 1 patient, two revisions were required because of instability and a persisting osteophyte, respectively. The rate of major complications was 7.1% (2/28). Surgical treatment of thoracic disc herniations via posterior approaches tailored to the individual patient produces satisfying results referring to clinical outcome. Posterior approaches remain a viable alternative for a large proportion of patients with symptomatic thoracic disc herniations.

Lows and highs: 15 years of development in intraoperative magnetic resonance imaging.

Intraoperative magnetic resonance imaging (ioMRI) during neurosurgical procedures was first implemented in 1995. In the following decade ioMRI and image guided surgery has evolved from an experimental stage into a safe and routinely clinically applied technique. The development of ioMRI has led to a variety of differently designed systems which can be basically classified in one- or two-room concepts and low- and high-field installations. Nowadays ioMRI allows neurosurgeons not only to increase the extent of tumor resection and to preserve eloquent areas or white matter tracts but it also provides physiological and biological data of the brain and tumor tissue. This article tries to give a comprehensive review of the milestones in the development of ioMRI and neuronavigation over the last 15 years and describes the personal experience in intraoperative low and high-field MRI.

Image guided aneurysm surgery in a Brainsuite® ioMRI Miyabi 1.5 T environment.

OBJECTIVE: Current literature only gives sparse account of aneurysm surgery in an intraoperative MRI environment. After installation of a BrainSuite(®) ioMRI Miyabi 1.5 T at our institution the aim of the present preliminary study was to evaluate feasibility, pros and cons of aneurysm surgery in this special setting. MATERIAL AND METHODS: Since February 2009, during a 3 months period we performed elective image guided aneurysm surgery in 4 ACM and 1 ACOM aneurysm (four patients) in this ioMRI setting. The patients' heads were rigidly fixed in the Noras 8-Channel OR Head Coil. Our imaging protocol included MP-RAGE, T2-TSE axial, TOF-MRA and diffusion-/perfusion-imaging immediately before surgery and after clip application. Presurgical 3D-planning was performed using the iPlan®-Software. RESULTS: All five aneurysms were operated without temporary clipping. There were no intra- or postoperative complications. Patient positioning and head fixation with the integrated Noras Head Clamp was feasible, but there were significant limitations particularly with regard to more complex approaches and patient physiognomy. Image quality especially TOF-MRA was good in 4, insufficient in 1 aneurysm. Presurgical planning especially vessel extraction from TOF-MRA was possible but certainly needs significant future improvement. Diffusion- and perfusion weighted examinations yielded good image quality. CONCLUSION: Our limited experience is encouraging so far. Further improvement particularly concerning flexibility of patient positioning and presurgical 3D-planning for vascular procedures is most necessary. As a future perspective image guided aneurysm surgery in an ioMRI-environment may be helpful especially in complex aneurysms and provide neurosurgeons and neuroanaesthesiologists with additional information about cerebral haemodynamics and perfusion pattern in the vascular territory distal to the target vessel.

Foramen magnum meningiomas--experience with the posterior suboccipital approach.

The aim of this study is to analyse short- and long-term results after surgical treatment of foramen magnum meningiomas and to identify the possible advantages of the posterior suboccipital approach over lateral and anterior approaches. Between 1992 and 2006, 16 patients with foramen magnum meningiomas were operated on in our institution, and in all cases a posterior suboccipital approach was utilised with lateral extension of the bone opening according to the position of the tumour. In 14 patients, intraoperative monitoring of the lower cranial nerves was performed. Localisation of the tumours was ventral (3), ventrolateral (10), dorsal (1) and dorsolateral (2). Mean age of the patients was 61 years (ranging from 40 to 85 years). Preoperative and postoperative function was classified according to the McCormick scale. We found in eight patients a postoperative upgrading of at least one grade, in five patients an unchanged status and a deterioration in only two patients. Complete removal of the tumour was possible in 14 cases (Simpson 1-2). The follow-up period varied from 24 to 119 months (mean 43.5 months), during this time there were no recurrences. Removal of foramen magnum meningiomas can be performed safely today with the use of microsurgical techniques and intraoperative monitoring. In our experience, the posterior suboccipital approach is suitable for the majority of these tumours.

[Traumatic peripheral nerve lesions : Diagnosis and treatment]. / Traumatische Läsionen peripherer Nerven : Diagnose und Therapie.

Traumatic peripheral nerve lesions affect patients of all age groups. They are associated with functional deficits that have severe consequences for affected patients and prolonged or permanent inability to work has socioeconomic relevance. In order to improve prognoses and achieve the best possible outcome an early diagnosis and competent knowledge of the correct approach and treatment strategies are essential. Unfortunately, nerve lesions are often not detected in time, so that surgical treatment can only be initiated after a delay. Because of the relatively high proportion of iatrogenic nerve lesions, a profound knowledge of the optimal care of patients with peripheral nerve lesions is compulsory for every doctor who works in the operative field. Surgical treatment of peripheral nerve lesions should remain in the hands of experienced peripheral nerve surgeons. The foundation of successful treatment, however, begins earlier at the initial referral when the patient receives the correct diagnostics and treatment.

[Diagnosis and therapy of carpal tunnel syndrome--guideline of the German Societies of Handsurgery, Neurosurgery, Neurology, Orthopaedics, Clinical Neurophysiology and Functional Imaging, Plastic, Reconstructive and Aesthetic Surgery, and Surgery for Traumatology]. / Diagnostik und Therapie des Karpaltunnelsyndroms--Leitlinie der Deutschen Gesellschaften für Handchirurgie, Neurochirurgie, Neurologie, Orthopädie unter Mitbeteiligung der Gesellschaften für Unfallchirurgie, Klinische Neurophysiologie und Funktionelle Bildgebung sowie Plastiche, Rekonstruktive und Asthetische Chirurgie.

Evidence-based supradisciplinary guideline that deals with the epidemiology, pathogenesis, symptoms, clinical and electrophysiological diagnosis, supplementary imaging investigations, differential diagnosis, conservative and surgical treatments, prognosis and course along with complications and revision surgery. The recommendations on investigation and treatment are based on a comprehensive literature search with critical evaluation and two consensus methods (expert group and Delphi technique) within the participating specialist societies. Besides this long version, a short version and a patient version can be viewed through the AWMF platform. The development of the guideline and the methodological foundations are documented in a method report. MAIN STATEMENTS: Apart from an accurate history and clinical neurological examination (including clinical tests), electrophysiological investigations (distal motor latency and sensory neurography) are particularly important. Radiography, MRI, high-resolution ultrasonography can be regarded as optional supplementary investigations. Among conservative treatment methods, treatment with a nocturnal splint and local infiltration of a corticosteroid preparation are effective. Oral steroids, splinting and ultrasound showed only short-term benefit. Surgical treatment is clearly superior to all other methods. Open and endoscopic procedures (when the endoscopic surgeon has sufficient experience) are equivalent. A routine epineurotomy and interfascicular neurolysis cannot be recommended. Early functional treatment postoperatively is important.

[Management of iatrogenic lesions of the spinal accessory nerve]. / Management iatrogener N.-accessorius-Läsionen.

Lesions of the spinal accessory nerve are usually iatrogenic, especially after lymph node extirpation on the neck. Between 1994 and 2003, 31 patients were operated on in the Neurosurgical Department of the University of Ulm for iatrogenic lesions of the XIth cranial nerve. Of 31 patients, 22 had undergone a previous lymph node extirpation, 2 had been injured during a selective peripheral denervation for spasmodic torticollis, and the other 7 patients by different causes. The neurosurgical intervention was performed 0-19 months after trauma (mean 7.2 months). All patients showed paresis/atrophy of the trapezius muscle, and the abduction of the shoulder was markedly reduced. Additional neck and/or shoulder pain was present in 29 of 31 cases. In seven cases, the nerve was compressed by scar tissue and subsequently treated by external neurolysis. Ten patients underwent an end-to-end anastomosis; autologous sural nerve grafting was necessary in 13 cases. After a mean follow-up of 12.6 months, 7 of 31 patients completely recovered. Of 31 patients, 19 experienced partial relief of pain and weakness. Only five patients remained unchanged. The clinical findings after autologous nerve grafting, end-to-end reconstruction, or external neurolysis did not show any significant differences. Microsurgical reconstruction of iatrogenic injury of the spinal accessory nerve is very promising if the interval between trauma and surgical revision is less than 6 months. Up to 12 months, partial recovery can be achieved. Outcome after longer delay is unsatisfactory.

The contribution of cavernous body biopsy in the diagnosis and treatment of male impotence.

This study concerns the results of penile biopsies in 50 patients aged 27 to 80, with secondary impotence removed with a biopty gun or during penile surgery. The biopty gun specimens were equally representative as the open biopsy ones. The cause and the degree of erectile dysfunction were determined by clinical and laboratorial investigation. The histological study of the cavernous bodies in the patients with psychogenic impotence revealed normal erectile tissue. In patients with organic impotence, histological lesions were graded as mild, moderate or severe. The most severe lesions were observed in the erectile tissue and in particular in the smooth muscle of the trabeculae and the helicine arteries, which had been reduced and replaced by connective tissue. Histological lesions were found not only in the arterial but also in the venous leak cases. There was a correlation between their severity and the degree of impotence, although of no statistical significance. The penile biopsy determines the condition (state) of the functional cavernous smooth muscle tissue, the integrity of which is essential for the erectile mechanism as well as for the action of the vasoactive drugs and the results of vascular surgery. Its important role is evident as it contributes not only to the diagnosis of the cause, but also to the choice of treatment of male impotence.

Pain after surgery for ulnar neuropathy at the elbow: a continuing challenge.

OBJECTIVE: Fifty-eight percent of patients who had undergone surgery for ulnar neuropathy at the elbow experienced pain after surgery. Severe pain, mostly radiating from the elbow into the hand, is the main indication for subsequent surgery. METHODS: During a period of 5.5 years, 25 patients underwent 28 operations for ulnar nerve entrapment at the elbow and experienced excruciating pain after surgery. Ten patients had undergone a simple decompression and 15 had undergone a nerve transposition. Seven patients underwent surgery at our hospital, whereas 18 patients underwent their primary surgery at other institutions. Various surgical techniques were used during the subsequent surgery, such as external or internal neurolysis, epineurectomy, anterior, transposition, and subsequent transfer of the nerve back into the sulcus. RESULTS: The average follow-up after the last procedure was 17 months (2-55 mo). All five patients with subsequent transfer of the ulnar nerve into the sulcus became pain-free, whereas only two of five patients who had secondary intramuscular transposition for subluxation became free of pain. Results after internal neurolysis were unsatisfactory. Only one of six patients was free of pain after secondary surgery. Results after three or four procedures are approximately similar to the results after the first subsequent surgery. CONCLUSION: Simple and less extensive techniques for subsequent surgery have relatively good results in this complicated condition. Although our small number of patients does not allow us to draw general conclusions, we think our report makes a contribution because of the few reports in the literature dealing with the results of subsequent surgery for ulnar nerve neuropathy.

Hemorrhage into a spinal ependymoma after peridural anesthesia.

The authors present a case of the accidental puncture of a spinal ependymoma causing bleeding and an increase in the preexisting neurological deficits.

Value of nerve action potentials in the surgical management of traumatic nerve lesions.

OBJECTIVE: The goals of the study were to investigate the value of intraoperative electrically evoked nerve action potentials (NAPs) in the surgical treatment of traumatic peripheral nerve injuries (nerve lesions in continuity). METHODS: Sixty-four patients with 76 traumatic nerve lesions in continuity were investigated intraoperatively by stimulating and recording NAP from the whole nerve across the suspected lesion site. Among the 76 nerves (nerve lesions) were 43 with incomplete and 33 with complete loss of function. In cases (nerves) with complete loss of function (n = 33), the surgical procedure (external neurolysis, internal neurolysis, or nerve repair) was performed according to the microscopic aspect of the nerve and the result of the intraoperative electrophysiological testing. In cases (nerves) with incomplete loss of function (n = 43), the surgical procedure was performed solely according to the microscopic aspect of the nerve and independently from the result of the intraoperative electrophysiological testing. RESULTS: Of 43 nerves with incomplete loss of function, we were able to record reproducible NAPs in 41 (95%) across the lesion site, thus demonstrating a high reliability of the method. Of 33 nerves with complete loss of function, a reproducible NAP could be recorded only in 3. Assuming an axonotmetic lesion in regeneration, we did nothing else on the nerve with excellent clinical results (full recovery). Of the remaining nerves with no NAP, 24 showed a caliber shift of the nerve (in 20 cases a thickening of the nerve, suggesting a neuroma in continuity). A grafting procedure was performed, and the histological evaluation revealed a neurotmetic lesion. However, in six patients with no NAP, there was no clear caliber shift of the nerve. The epineurium was opened and an internal neurolysis performed showing fascicles in continuity. Three patients had good and three had partial (but useful) recovery. CONCLUSIONS: In nerve lesions in continuity with complete loss of nerve function, intraoperative NAPs are able to detect axonotmetic lesions in regeneration. Thus, unnecessary further surgical procedures can be avoided. On the other end of the spectrum, no recordable NAP together with a caliber shift of the nerve (suggesting a neuroma in continuity) may facilitate the surgeon's decision for a grafting procedure without a time-consuming internal neurolysis. But there is also evidence from our data that not every nerve lesion in continuity without a NAP needs to be grafted.

Reconstruction of the spinal accessory nerve with an anastomosis to the dorsal C3 branch: technical note.

Most lesions of the spinal accessory nerve are of traumatic origin. If the proximal part is sectioned next to its exit from the cranial base, the reconstruction might be difficult. In such a case, one option is intracranial identification of the spinal accessory nerve and transdural interposition of a graft to its distal stump. Cerebrospinal fluid leaks or infections, caudal nerve palsies, or even spinal neurological deficits are possible complications. From more than 70 patients who underwent selective peripheral denervations for the treatment of spasmodic torticollis in our department, we have learned that the dorsal C1-C6 branches can be sectioned without any functional impairment. The dorsal C2 and C3 branches have diameters comparable to that of the spinal accessory nerve. They contain between 600 and 700 myelinated fibers per square millimeter. Therefore, they seem to be ideal proximal donors for the reconstruction of a severed motor nerve. They may be used in patients with peripheral nerve injuries in the craniocervical region, if other possibilities are not suitable.

A comparison of recurrent inhibition and of paired-pulse facilitation in hippocampal slices from normal and genetically epileptic mice.

Tottering mice exhibit inherited generalized epilepsy of the 'absence' type. In hippocampal slices from these mutant mice studied in vitro, pairing an alvear antidromic stimulus to an orthodromic one revealed a strong recurrent inhibition (RI) of CA1 pyramidal neurons. RI was maximal at 10 ms inter-pulse interval (IPI 70% decrease of population spike, PS) gradually decreasing to 15% at 320 ms IPI. At 10 ms IPI it shifted the input/output curves to the right and decreased maximum PS. In the group of slices from epileptic mice the early part of RI (2.5-60 ms) was indistinguishable from that of normal mice, with respect to both its strength and its liability to activity-dependent decrement induced by a train of antidromic stimuli (8 s, 5 Hz). However, the delayed part (80-320 ms) was slightly stronger in the epileptic group. Also in this group only the train of antidromic pulses caused a significant and lasting decrease in the unconditioned orthodromic PS. Paired-pulse facilitation was equally strong in the 2 groups of slices. It is concluded that mechanisms underlying epileptogenic hyperexcitability in the tottering mutant may not include a failure of inhibition, at least in the CA1 area of the hippocampus. On the contrary some inhibitory mechanisms may be stronger.

Suprascapular nerve entrapment: experience with 28 cases.

Suprascapular nerve entrapment (SNE) in the suprascapular notch is a rare entity that must be considered in the differential diagnosis of radicular pain, as well as that of shoulder discomfort. Over a period of 10 years (1985-1995), the authors treated 28 cases of SNE in 27 patients by surgical decompression of the nerve. One patient underwent operation bilaterally within 5 years. Five patients presented with a history of trauma to the shoulder region. In three patients, a ganglion cyst was the origin of the nerve lesion. In 16 patients, the nerve problem was primarily related to athletic activities. Eight of these patients were professional volleyball players. In the remaining three patients, there was no relationship between the nerve lesion and trauma or athletic activities. Twenty-one patients (22 cases) complained of pain located over the suprascapular notch. Seventeen patients had paresis and atrophy of both the supraspinatus (SS) and infraspinatus (IS) muscles. In 10 patients only the IS muscle was involved. One patient exhibited a sensory deficit over the posterior portion of the shoulder. Electromyography was performed in all cases. The mean follow-up period in the 25 cases (24 patients) that could be evaluated was 20.8 months (range 3-70 months). Nineteen of 22 cases with preoperative pain could be evaluated. Sixteen of these patients were completely free of pain after surgery and three patients found their pain had improved. Motor function in the SS muscle improved in 86.7% and motor function in the IS muscle in 70.8% of cases. Atrophy of the SS muscle resolved in 80.7% and atrophy of the IS muscle in 50% of cases. Surgical treatment of SNE is indicated after failed conservative treatment and in cases of atrophy of the SS and IS muscles. The authors recommend the posterior approach, which minimizes risks and complications and produces good postoperative results.

Evaluation of iatrogenic lesions in 722 surgically treated cases of peripheral nerve trauma.

OBJECT: The purpose of this study was to discover the number and types of iatrogenic nerve injuries that were surgically treated during a 9-year period at a relatively busy nerve center. The specific nerves involved, their sites of injury, and the mechanisms of injury were also documented. METHODS: The authors retrospectively evaluated the surgically treated iatrogenic lesions by reviewing case histories, operative reports, and follow-up notes in 722 cases of trauma. These cases were treated between January 1990 and December 1998 because of pain, dysesthesias, and sensory and/or motor deficits. latrogenic injury was a much larger category of trauma than predicted. One hundred twenty-six (17.4%) of the 722 surgically treated cases were iatrogenic in origin. Most of these injuries occurred during a previous operation. To a major extent, nerves of the extremities were affected, and a relatively large number of injuries occurred in the neck and groin. Incidence was highest in the spinal accessory nerve (14 cases), the common peroneal nerve (11 cases), the superficial radial nerve (10 cases), the genitofemoral nerve branches (10 cases), and the median nerve (nine cases). At least two thirds of the patients did not undergo surgery for the iatrogenic injury within an optimal time interval due to delayed referral. Follow-up data were available in 97 of the 126 patients. Surgical outcomes demonstrated improvement in 70% of patients. Operative results were especially favorable in patients suffering from iatrogenic injuries to the accessory and superficial sensory radial nerves. CONCLUSIONS: latrogenic injuries should be corrected in a timely fashion just like any other traumatic injury to nerve.