[Development of epidural spinal cord stimulation. Fortieth anniversary of the first implantation in Germany]. / Entwicklung der epiduralen Rückenmarkstimulation. 40 Jahre seit der Erstimplantation in Deutschland.

Spinal cord stimulation is nowadays an established therapy for various neuropathic and vasculopathic pain syndromes after more conservative measures have failed. However, 40 years ago, only 5 years after the first worldwide implantation in the US, this therapy was promoted in Germany. In 1972, the first devices were implanted in the Departments of Neurosurgery at the Universities Hannover and Freiburg. These pioneering efforts and the establishment of the therapy are intimately associated with three names: Jörg-Ulrich Krainick, Uwe Thoden, and Wolfhard Winkelmüller. Nowadays about 1700 spinal cord stimulation systems are implanted annually in Germany. The development of spinal cord stimulation from the beginnings up to now taking into special consideration the early years in Germany are presented.

Respiratory systolic variation test in acutely impaired cardiac function for predicting volume responsiveness in pigs.

BACKGROUND: Predicting the response of cardiac output (CO) to volume administration remains difficult, in particular in patients with acutely compromised cardiac function, where, even small amounts of i.v. fluids can lead to volume overload. We compared the ability to predict volume responsiveness of different functional haemodynamic parameters, such as pulse pressure variation (PPV), stroke volume variation (SVV), the static preload parameter right atrial pressure (RAP), and global end-diastolic volume (GEDV) with the recently proposed respiratory systolic variation test (RSVT) in acutely impaired cardiac function. METHODS: In 13 mechanically ventilated pigs, cardiac function was acutely reduced by continuous application of verapamil to reach a decrease in peak change of left ventricular pressure over time (dP/dt) of 50%. After withdrawal of 20 ml kg(-1) BW blood to establish hypovolaemia, four volume loading steps of 7 ml kg(-1) BW using the shed blood and 6% hydroxyethylstarch 130/0.4 were performed. Volume responsiveness was considered as positive, if CO increased more than 10%. RESULTS: Receiver operating characteristic curve analysis revealed an area under the curve (AUC) of 0.88 for the RSVT, 0.84 for PPV, 0.82 for SVV, 0.78 for RAP, and 0.77 for GEDV. CONCLUSIONS: Functional parameters of cardiac preload, including the RSVT, allow prediction of fluid responsiveness in an experimental model of acutely impaired cardiac function.

[Immunonutrition after trauma]. / Immunonutrition nach Trauma.

Immunonutrition may be superior to standard clinical nutrition in specific clinical situations. After severe trauma, an enteral immuno-enhancing diet, enriched with arginine, omega-3 fatty acids, and nucleotides, decreases infectious complications. During acute respiratory distress syndrome, a continuous enteral diet with high-dose omega-3 fatty acids, gamma-linolenic acid, and antioxidants improved clinical outcome. Glutamine should be administered enterally or parenterally whenever total parenteral nutrition is indicated.

Involvement of the GTP binding protein Rho in constitutive endocytosis in Xenopus laevis oocytes.

To study an endocytotic role of the GTP-binding protein RhoA in Xenopus oocytes, we have monitored changes in the surface expression of sodium pumps, the surface area of the oocyte and the uptake of the fluid-phase marker inulin. Xenopus oocytes possess intracellular sodium pumps that are continuously exchanged for surface sodium pumps by constitutive endo- and exocytosis. Injection of Clostridium botulinum C3 exoenzyme, which inactivates Rho by ADP-ribosylation, induced a redistribution of virtually all intracellular sodium pumps to the plasma membrane and increased the surface area of the oocytes. The identical effects were caused by injection of ADP-ribosylated recombinant RhoA into oocytes. The C3 exoenzyme acts by blocking constitutive endocytosis in oocytes, as determined using a mAb to the beta 1 subunit of the mouse sodium pump as a reporter molecule and oocytes expressing heterologous sodium pumps. In contrast, an increase in endocytosis and a decrease in the surface area was induced by injection of recombinant Val14-RhoA protein or Val14-rhoA cRNA. PMA stimulated sodium pump endocytosis, an effect that was blocked by a specific inhibitor of protein kinase C (Gö 16) or by ADP-ribosylation of Rho by C3. Similarly, the phorbol ester-induced increase in fluid-phase endocytosis in oocytes was inhibited by Gö 16, C3 transferase, or by injection of ADP-ribosylated RhoA. In contrast to C3 transferase, C. botulinum C2 transferase, which ADP-ribosylates actin, had no effect on sodium pump endocytosis or PMA-stimulated fluid-phase endocytosis. The data suggests that RhoA is an essential component of a presumably clathrin-independent endocytic pathway in Xenopus oocytes which can be regulated by protein kinase C.

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.

[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.

Ferromagnetic isolation of endosomes involved in vitellogenin transfer into Xenopus oocytes.

The transport pathway of the yolk precursor vitellogenin (VTG) has been followed using the techniques of ferrolabeling and ferromagnetic sorting, coupled with electron microscopic visualization. Vitellogenin conjugated to colloidal ferric particles of ca. 11 nm is selectively transported from the oolemma to the yolk platelets of vitellogenic Xenopus oocytes after gonadotropin stimulation of the female. Several cortical membrane compartments, labeled or unlabeled with ferric particles, are involved in the internalization and the transfer of vitellogenin to the yolk platelets. 1) Coated pits apparently fuse with coated vesicles, and coated vesicles fuse with each other in the outermost cortical cytoplasm. 2) Vesicles, depleted of their clathrin coat, fuse with cortical tubular endosomes and discharge their contents into yolk endosomes. 3) These endosomes are the direct precursors of the yolk organelles. 4) Endocytic vesicles fuse only with primordial yolk platelets of type I and not with type II or fully grown yolk platelets. After pulse-chase loading with ferric particles conjugated to vitellogenin and subsequent subcellular fractionation of the oocytes, ferromagnetic sorting of the various vesicle populations has been performed by using a "free-flow magnetic chamber". This novel method enables specification and characterization of purified endosomal compartments that accumulate protein yolk in Xenopus oocytes.

Electric Field-induced Fusion of Sea Urchin Eggs.

An electrical method is described which permits the fusion of denuded eggs of the sea urchin species Paracentrotus lividus. In a nearly non-conductive medium, containing 1.2 M glucose at pH 6.0-8.4, eggs or fertilized stages are brought into close membrane contact by dielectrophoresis arising from the application of a highly inhomogeneous alternating electric field. During this process the eggs aligne parallel to the field forming "egg-chains". In well pigmented eggs pigmentcapping is observed in the areas of cell contact. After completion of the alignment, the application of an additional single high field pulse of µs duration induces fusion of two or more eggs. The mechanism underlying the fusion process is the reversible electric breakdown of membranes in the zones of cell-to-cell contact. Fusion proceeds within 1-10 min at 10-20°C. Fused eggs have intact nuclei, can be fertilized, but undergo abortive cleavage.

Mobility of Membrane Lipids and Proteins at the Animal and Vegetal Pole of the Sea Urchin Egg: (sea urchin/polarity/plasma membrane/translational mobility/fluorescence microphotolysis, photobleaching).

We have compared the mobility of a fluorescent lipid analogue and of fluorescently labeled membrane proteins at the animal and vegetal poles of the egg of the sea urchin Paracentrotus lividus. Translational diffusion coefficients have been measured by fluorescence microphotolysis ("photo-bleaching") on the egg which was rotated on its poles. Lipid and protein diffusion coefficients averaged 0.8 µm2 /sec and 0.04 µm2 /sec, respectively at both animal and vegetal pole of the egg. Substances which were known to animalize (Zn++ ) or vegetalize (Li+ ) the sea urchin egg had no significant effect on protein diffusion coefficients.

Selective peripheral denervation for spasmodic torticollis: is the outcome predictable?

If botulinum toxin fails in the treatment of cervical dystonia, selective peripheral denervation is now accepted as the best surgical option. Despite the very promising results, however, there is still a substantial group of patients who do not benefit from this procedure. Positive response to prior botulinum toxin therapy seems to be a very good predictor of outcome after selective peripheral denervation (P < 0.01). The meaning of the histological findings of the resected nerves is uncertain. Patients with histologically proven pathological nerves do not seem to benefit more than patients with histological normal ones (P < 0.30).

Impairment of motor recovery after late nerve suture: experimental study in the rabbit. Part 1: functional and electromyographic findings.

To study the motor recovery after increasingly late nerve suture, we severed 75 rabbit peroneal nerves and reanastomosed them by microsurgical epineural technique after a delay of up to 12 months. Functional, electromyographic, and morphological parameters were used to evaluate the quality of motor function 6 months after suture. This first part of the study deals with the functional (toe-spreading reflex) and electromyographic findings. With increasing denervation intervals before the nerve suture, significant (p less than 0.01) changes were observed 6 months later. Spontaneous electromyographic activity was seen more frequently, and the strength of toe spreading decreased. The amplitude of the muscle action potential, which became polyphasic, also decreased. The latency and duration of the muscle action potential did not change significantly with an increasing denervation interval before nerve suture.

Selective peripheral denervation for the treatment of spasmodic torticollis.

The results of selective peripheral denervation in 50 patients with spasmodic torticollis are presented. Of our patients, 76% reported a significant improvement or disappearance of their dystonia. The mean follow-up is 25 months. There were no major side effects. We recommend the procedure to patients who primarily have responded to botulinum toxin therapy and had become secondary nonresponders or to those refusing further injections while still responding. The results are much less promising in patients who are primary nonresponders to botulinum toxin. Some remarkable histological findings are presented. The posterior branches of the cervical roots frequently showed signs of severe compression neuropathy. In three cases, a functional motor nerve regeneration was proved. Among all surgical options, selective peripheral denervation provides the best result and has the fewest side effects.

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.

Preoperative embolization of intracranial meningiomas.

The operative and histopathological findings in 31 cases of intracranial meningioma after preoperative embolization with Gelfoam and/or lyophilized dura mater are reported. Removal of the tumor after embolization was facilitated in those meningiomas fed exclusively or mainly by branches of the external carotid artery (29 of 31). Large areas of tumor necrosis were never seen on histopathological examination, even when suggested by large regions of decreased density on the postembolization computed tomographic scan. Preoperative embolization of the feeding vessels arising from the external carotid artery system has proven to be a useful adjunct before the resection of intracranial meningiomas.

Is the substantia gelatinosa the target in dorsal root entry zone lesions? An autopsy report.

The autopsy findings in a patient who died from a massive myocardial infarction 5 days after a cervical DREZ lesion for deafferentation pain are reported. The trauma had caused a substantial defect involving the ipsilateral Lissauer's tract and the substantia gelatinosa, as well as more medial parts of the posterior horn. The positive effect of the radiofrequency coagulation must have been caused by a lesion outside Lissauer's tract and the substantia gelatinosa.

Dorsal root entry zone lesions for the control of deafferentation pain: experiences in ten patients.

Experiences with radiofrequency lesions of the dorsal root entry zone in 10 patients are reported. All of these patients suffered from central (deafferentation) pain. The early postoperative results were poor in the 2 patients with traumatic paraplegia and good in all 8 patients with pain in the cervical segments. Two patients treated with cervical DREZ lesions died. In 2 of the remaining 6 patients with cervical lesions, pain recurred. Four had a good result up to 30 months after operation.

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.

Intracerebral aspergillus abscess: case report.

Intracranial aspergillosis is rare and often fatal. The authors report the successful treatment of a right temporal intracerebral aspergillus abscess.

Neurosurgical management of thoracic and lumbar vertebral osteomyelitis and discitis in adults: a review of 43 consecutive surgically treated patients.

We report 43 consecutive surgically treated patients with pyogenic (37 patients) and tuberculous (6 patients) osteomyelitis of the thoracic and lumbar spine encountered within an 8-year period, including 1 with late recurrence after 15 months. There were 24 men and 18 women, ranging in age from 21 to 83 years. Twenty-six patients were in poor general condition because of associated illnesses, especially diabetes mellitus. Disease occurred at the thoracic level in 19 patients and on the lumbar spine in 24. After diagnosis, five patients were merely treated by posterior decompression; three of them, however, required further surgery for recurrent infection, spinal instability, and secondary neurological impairment. They are included in the 40 patients who underwent combined posterior débridement and internal fixation with transpedicular screw-rod systems. Autologous interbody bone grafting was performed simultaneously in 18 patients and in a second stage operation in 21 patients. One of them (tuberculous) experienced early recurrence and required anterior fusion. In two patients, methylmethacrylate packing was used for spine reconstruction; one of them had a late recurrence. Of the 26 patients with preoperative marked or severe neurological deficit (Frankel Grades A, 2 patients; B, 1 patient; C, 17 patients; and D, 6 patients), 23 (88%) had significant improvement of one grade (15 patients) or more (8 patients). There were no permanent complications. However, intensive care treatment was necessary in 20 of the 26 patients in reduced general condition (mean age, 72 yr). Two patients required further surgery because of postoperative epidural hematoma and pedicle screw malpositioning. In conclusion, most patients with thoracic and lumbar osteomyelitis can be successfully treated by combined débridement and internal fixation using only a posterior approach. Autogenous interbody bone grafting can be simultaneously performed and allows early mobilization of the patient.

Findings and long-term results of subsequent operations after failed microvascular decompression for trigeminal neuralgia.

OBJECTIVE: To evaluate the indication of subsequent operations after failed microvascular decompression (MVD) for the treatment of trigeminal neuralgia, the intraoperative findings and long-term results of 16 subsequent operations are reported. METHODS: Subsequent exploration of the posterior fossa was performed for lack of pain relief (3 patients) and recurrent neuralgia (13 patients) after an average of 17 months (range, 4-62 mo). In all patients, typical arterial compression patterns at the root entry zone of the trigeminal nerve were found in the first procedure. The mean follow-up period after subsequent operation was 90 months (range, 78-104 mo). RESULTS: New arterial neurovascular conflicts were found in nine patients. After subsequent MVD procedures, seven patients were pain-free (with one recurrence after 6 mo), one had constant marked relief, and one was unchanged. Second exploration revealed no abnormalities in the other seven patients who experienced continued or recurrent pain; only careful neurolysis of the trigeminal nerve was performed in those patients. Initially, all seven patients obtained complete pain relief, but two experienced late recurrences after 64 and 68 months, respectively. Thus, subsequent operations failed in all 4 patients who had undergone prior destructive procedures but were successful in those 12 patients who had undergone only previous MVD. Two patients developed severe sequelae, and the other nine had minor complications, especially permanent (four patients) or transitory (three patients) ipsilateral trigeminal hypoesthesia. CONCLUSION: Subsequent MVD seems to have good long-term results. However, because of the significantly high incidence of complications, the indication for subsequent operations should be restricted to younger patients to avoid destructive procedures. In general, glycerol rhizolysis or radiofrequency rhizotomy may be the treatment of choice after failed MVD.