[Interdisciplinary multimodal pain therapy in postviral syndromes and ME/CFS : Features, pitfalls and model concept]. / Interdisziplinäre multimodale Schmerztherapie bei postviralen Syndromen und ME/CFS : Besonderheiten, Fallstricke und Modellkonzept.

BACKGROUND: Multimodal pain therapy usually take place in the context of group therapy lasting several weeks and is based on a generally activating approach. Due to the specificity of stress intolerance with postexertional malaise (PEM) in patients with postviral syndromes, physical as well as psychological overload must be urgently avoided in these cases; however, these aspects can only be insufficiently considered in current medical pain therapy concepts. METHODS: Summary of the current literature and presentation of clinical characteristics as well as presentation of a model project for a multimodal pain therapy in postviral syndromes with PEM. MODEL CONCEPT: The presented model project describes a day clinic treatment setting for interdisciplinary multimodal pain therapy adapted to the individual resilience with minimization of the risk of strain-induced deterioration of the condition.

Individually optimized hemodynamic therapy reduces complications and length of stay in the intensive care unit: a prospective, randomized controlled trial.

BACKGROUND: The authors hypothesized that goal-directed hemodynamic therapy, based on the combination of functional and volumetric hemodynamic parameters, improves outcome in patients with cardiac surgery. Therefore, a therapy guided by stroke volume variation, individually optimized global end-diastolic volume index, cardiac index, and mean arterial pressure was compared with an algorithm based on mean arterial pressure and central venous pressure. METHODS: This prospective, controlled, parallel-arm, open-label trial randomized 100 coronary artery bypass grafting and/or aortic valve replacement patients to a study group (SG; n = 50) or a control group (CG; n = 50). In the SG, hemodynamic therapy was guided by stroke volume variation, optimized global end-diastolic volume index, mean arterial pressure, and cardiac index. Optimized global end-diastolic volume index was defined before and after weaning from cardiopulmonary bypass and at intensive care unit (ICU) admission. Mean arterial pressure and central venous pressure served as hemodynamic goals in the CG. Therapy was started immediately after induction of anesthesia and continued until ICU discharge criteria, serving as primary outcome parameter, were fulfilled. RESULTS: Intraoperative need for norepinephrine was decreased in the SG with a mean (±SD) of 9.0 ± 7.6 versus 14.9 ± 11.1 µg/kg (P = 0.002). Postoperative complications (SG, 40 vs. CG, 63; P = 0.004), time to reach ICU discharge criteria (SG, 15 ± 6 h; CG, 24 ± 29 h; P < 0.001), and length of ICU stay (SG, 42 ± 19 h; CG, 62 ± 58 h; P = 0.018) were reduced in the SG. CONCLUSION: Early goal-directed hemodynamic therapy based on cardiac index, stroke volume variation, and optimized global end-diastolic volume index reduces complications and length of ICU stay after cardiac surgery.

Heart-lung interactions measured by electrical impedance tomography.

OBJECTIVE: The clinical value of stroke volume variations to assess intravascular fluid status in critically ill patients is well known. Electrical impedance tomography is a noninvasive monitoring technology that has been primarily used to assess ventilation. We investigated the potential of electrical impedance tomography to measure left ventricular stroke volume variation as an expression of heart-lung interactions. The objective of this study was thus to determine in a set of different hemodynamic conditions whether stroke volume variation measured by electrical impedance tomography correlates with those derived from an aortic ultrasonic flow probe and arterial pulse contour analysis. DESIGN: Prospective animal study. SETTING: University animal research laboratory. SUBJECTS: Domestic pigs, 29-50 kg. INTERVENTIONS: A wide range of hemodynamic conditions were induced by mechanical ventilation at different levels of positive end-expiratory pressure (0-15 cm H2O) and with tidal volumes of 8 and 16 mL/kg of body weight and by hypovolemia due to blood withdrawal with subsequent retransfusion followed by infusions of hydroxyethyl starch. MEASUREMENTS AND MAIN RESULTS: In eight pigs, aortic stroke volume variations measured by electrical impedance tomography were measured and compared to those derived from an aortic ultrasonic flow probe and from arterial pulse contour analysis. Data for four animals were used to develop and train a novel frequency-domain electrical impedance tomography analysis algorithm, while data for the remaining four were used to test the performance of the novel methodology. Correlation of stroke volume variation measured by electrical impedance tomography and that derived from an aortic ultrasonic flow probe was significant (r = 0.69; p < .001), as was the correlation between stroke volume variation measured by electrical impedance tomography and that derived from arterial pulse contour analysis (r = 0.73; p < .001). Correlation of stroke volume variation derived from an aortic ultrasonic flow probe and that derived from arterial pulse contour analysis was significant too (r = 0.82; p < .001). Bland-Altman analysis comparing stroke volume variation measured by electrical impedance tomography and that derived from an aortic ultrasonic flow probe revealed an overall bias of 1.87% and limits of agreement of ± 7.02%; when comparing stroke volume variation measured by electrical impedance tomography and that derived from arterial pulse contour analysis, the overall bias was 0.49% and the limits of agreement were ± 5.85%. CONCLUSION: Stroke volume variation measured by electrical impedance tomography correlated with both the gold standard of direct aortic blood flow measurements of stroke volume variation and pulse contour analysis, marking an important step toward a completely noninvasive monitoring of heart-lung interactions.

Thermodilution-derived indices for assessment of left and right ventricular cardiac function in normal and impaired cardiac function.

OBJECTIVE: The aim of this study was to assess whether thermodilution-derived parameters of right and left ventricular cardiac function (right ventricular ejection fraction, global ejection fraction, cardiac function index) are able to track changes of cardiac contractile function and whether they are influenced by substantial preload reduction. DESIGN: Prospective animal study. SETTING: University-affiliated animal research laboratory. SUBJECTS: Domestic pigs. INTERVENTIONS: Sixteen domestic pigs were studied. Right ventricular ejection fraction, global ejection fraction, and cardiac function index were compared to direct measurement of left ventricular rate of maximum systolic pressure rise and the left ventricular rate of maximum systolic pressure rise corrected to preload. Measurements were done with normal cardiac function during normo- and hypovolemia. Thereafter, cardiac function was impaired by continuous infusion of verapamil and measurements were repeated during normo- and hypovolemia (withdrawal of blood 20 mL kg body weight). MEASUREMENTS AND MAIN RESULTS: With normal cardiac function, hypovolemia led to a significant decrease of right ventricular ejection fraction from 36.7% ± 6.6% to 29.8% ± 5.8% (p < .001), global ejection fraction from 40.5% ± 6.2% to 33.6% ± 7.6% (p < .001), and the left ventricular rate of maximum systolic pressure rise from 2104 ± 390 mm Hg sec to 1297 ± 438 mm Hg sec (p < .001). Cardiac function index (8.92 ± 2.20 min to 7.93 ± 1.54 min) and the left ventricular rate of maximum systolic pressure rise corrected to preload (18.2 ± 4.7 mm Hg sec mL to 15.2 ± 4.3 mm Hg sec mL) did not change significantly. Infusion of verapamil led to a significant reduction of right ventricular ejection fraction, global ejection fraction, cardiac function index, the left ventricular rate of maximum systolic pressure rise, and the left ventricular rate of maximum systolic pressure rise corrected to preload (p < .001). Now, hypovolemia led to a significant decrease of right ventricular ejection fraction (29.1% ± 4.6% to 24.9% ± 5.9%; p < .001), global ejection fraction (37.1% ± 4.7% to 31.9% ± 3.9%; p < .05), cardiac function index (7.58 ± 1.02 to 6.27 ± 1.19 min; p < .05), and the left ventricular rate of maximum systolic pressure rise (733 ± 141 mm Hg sec to 426 ± 108 mm Hg sec; p < .05). Only the left ventricular rate of maximum systolic pressure rise corrected to preload did not change significantly (6.7 ± 1.3 mm Hg sec mL to 4.6 ± 1 mm Hg sec mL; p > .05). CONCLUSIONS: Right ventricular ejection fraction, global ejection fraction, and cardiac function index enable detection of changes in load-independent, intrinsic cardiac contractility. Importantly, they also reflect changes of contractile function caused by substantial decrease of preload, emphasizing the importance of assessing both cardiac contractile function in coherence with cardiac preload to differentiate between reduced intrinsic contractility and hypovolemia.

Detection of right ventricular insufficiency and guidance of volume therapy are facilitated by simultaneous monitoring of static and functional preload parameters.

OBJECTIVE: Acute right ventricular failure (RVF) is a life-threatening condition. This study investigated whether the combination of central venous pressure (CVP) and left ventricular functional preload parameters, such as stroke volume variation (SVV) and pulse pressure variation (PPV), can be used for the detection of acute RVF and for guidance of volume therapy. DESIGN AND SETTING: Experimental study in a university laboratory. PARTICIPANTS: Fifteen anesthetized and ventilated pigs. MEASUREMENTS AND MAIN RESULTS: For the induction of RVF, mean pulmonary artery pressure (MPAP) was increased by 50% with a continuous infusion of a thromboxane-A(2) analog (U46619). Then, blood removal (300 mL) and retransfusion (blood 200 mL + colloid solution 200 mL) were performed. An analysis of volume responders and nonresponders was implemented. Increasing MPAP (25.1 to 37.4 mmHg) led to decreases in mean arterial pressure (72.2 to 60.1 mmHg) and cardiac output (2.8 to 2.3 L/min, p < 0.05). CVP (11.3 to 12.6 mmHg), PPV (13% to 17%), and SVV (11 to 14%) increased significantly (p < 0.05). During volume removal, MPAP (37.4 to 34.1 mmHg), mean arterial pressure (60.1 to 53.2 mmHg), and cardiac output (2.3 to 2.1 L/min) decreased (p < 0.05), whereas PPV and SVV remained unchanged. During volume loading, CVP increased in volume responders and nonresponders; however, PPV decreased in responders only. CONCLUSIONS: Increases of CVP and SVV or PPV are suspicious for RVF. However, SVV and PPV fail to predict volume responsiveness in RVF. Changes in SVV and PPV during a volume-loading maneuver can be used to assess volume responsiveness.

Unique paleopathology in a pre-Columbian mummy remnant from Southern Peru--severe cervical rotation trauma with subluxation of the axis as cause of death.

We describe the multidisciplinary findings in a pre-Columbian mummy head from Southern Peru (Cahuachi, Nazca civilisation, radiocarbon dating between 120 and 750 AD) of a mature male individual (40-60 years) with the first two vertebrae attached in pathological position. Accordingly, the atlanto-axial transition (C1/C2) was significantly rotated and dislocated at 38° angle associated with a bulging brownish mass that considerably reduced the spinal canal by circa 60%. Using surface microscopy, endoscopy, high-resolution multi-slice computer tomography, paleohistology and immunohistochemistry, we identified an extensive epidural hematoma of the upper cervical spinal canal-extending into the skull cavity-obviously due to a rupture of the left vertebral artery at its transition between atlas and skull base. There were no signs of fractures of the skull or vertebrae. Histological and immunohistochemical examinations clearly identified dura, brain residues and densely packed corpuscular elements that proved to represent fresh epidural hematoma. Subsequent biochemical analysis provided no evidence for pre-mortal cocaine consumption. Stable isotope analysis, however, revealed significant and repeated changes in the nutrition during his last 9 months, suggesting high mobility. Finally, the significant narrowing of the rotational atlanto-axial dislocation and the epidural hematoma probably caused compression of the spinal cord and the medulla oblongata with subsequent respiratory arrest. In conclusion, we suggest that the man died within a short period of time (probably few minutes) in an upright position with the head rotated rapidly to the right side. In paleopathologic literature, trauma to the upper cervical spine has as yet only very rarely been described, and dislocation of the vertebral bodies has not been presented.

Decrease in adhesion molecules on polymorphonuclear leukocytes of patients with fibromyalgia.

Fibromyalgia (FM) is a chronic widespread pain condition in highly stressed humans. Because stress is known to modulate adhesion molecule expression, we determined L: -selectin (CD62L) and beta(2)-integrin (CD11b/CD18) expression on the surface of polymorphonuclear leukocytes in 22 patients with FM. As compared to age and sex-matched healthy controls, FM patients showed a significantly decreased expression of CD62L (p < 0.01) and CD11b/CD18 (p < 0.05) on polymorphonuclear leukocytes. These changes might lower the rate of polymorphonuclear leukocyte migration to sites of inflammation and thereby compromise defense against infections and pain control.

High-resolution ultrasonography in evaluating peripheral nerve entrapment and trauma.

High-resolution ultrasonography is a noninvasive, readily applicable imaging modality, capable of depicting real-time static and dynamic morphological information concerning the peripheral nerves and their surrounding tissues. Continuous progress in ultrasonographic technology results in highly improved spatial and contrast resolution. Therefore, nerve imaging is possible to a fascicular level, and most peripheral nerves can now be depicted along their entire anatomical course. An increasing number of publications have evaluated the role of high-resolution ultrasonography in peripheral nerve diseases, especially in peripheral nerve entrapment. Ultrasonography has been shown to be a precious complementary tool for assessing peripheral nerve lesions with respect to their exact location, course, continuity, and extent in traumatic nerve lesions, and for assessing nerve entrapment and tumors. In this article, the authors discuss the basic technical considerations for using ultrasonography in peripheral nerve assessment, and some of the clinical applications are illustrated.

Anesthesia during cardiologic procedures.

PURPOSE OF REVIEW: Cardiovascular diseases are counted among the most prevalent morbidities in western nations and they still are the leading cause of death in these countries. An increasingly aging population will confront all physicians with a growing number of patients having cardiovascular dysfunction. Anesthesiologists need to be familiar with upcoming new cardiologic procedures to provide hemodynamic stability during these procedures. RECENT FINDINGS: Cardiovascular diseases are often combined with severe comorbidities such as renal failure, chronic obstructive pulmonary disease, pulmonal hypertension and cerebrovascular damage. So anesthesia in this cohort requires experience, especially when during direct manipulation of the cardiac system such as in cardiologic procedures. Additionally, a new therapeutic option has been developed for valvular dysfunction recently, which involves the anesthesiologist in a new treatment of a high-risk population. SUMMARY: This review will focus on anesthesiological management of patients undergoing implantation of pacemakers and defibrillators, coronary interventions and interventions in the rapidly growing field of percutaneous treatment of mitral and aortic valve failure.

Anandamide and neutrophil function in patients with fibromyalgia.

Fibromyalgia (FM) is a common stress-related painful disorder. There is considerable evidence of neuroimmunologic alterations in FM which may be the consequence of chronic stress and pain or causally involved in the development of this disorder. The endocannabinoid system has been shown to play a pivotal role in mammalian nociception, is activated under stressful conditions and can be an important signaling pathway for immune modulation. The endocannabinoid system could therefore be involved in the complex pathophysiology of FM. We tested this hypothesis by evaluating the effects of stress hormones and the endocannabinoid anandamide on neutrophil function in patients with FM. We determined plasma levels of catecholamines, cortisol and anandamide in 22 patients with primary FM and 22 age- and sex-matched healthy controls. Neutrophil function was characterized by measuring the hydrogen peroxide (H2O2) release (oxidative stress) and the ingestion capabilities of neutrophils (microbicidal function). FM patients had significantly higher norepinephrine and anandamide plasma levels. Neutrophils of FM patients showed an elevated spontaneous H2O2 production. The ability of neutrophils to adhere was negatively correlated with serum cortisol levels. Adhesion and phagocytosis capabilities of neutrophils correlated positively with anandamide plasma levels. In conclusion, patients with FM might benefit from pharmacologic manipulation of endocannabinoid signaling which should be tested in controlled studies.

Accuracy of pedicle screw insertion in the cervical spine for internal fixation using frameless stereotactic guidance.

OBJECT: Although transpedicular fixation is a biomechanically superior technique, it is not routinely used in the cervical spine. The risk of neurovascular injury in this region is considered high because the diameter of cervical pedicles is very small and their angle of insertion into the vertebral body varies. This study was conducted to analyze the clinical accuracy of stereotactically guided transpedicular screw insertion into the cervical spine. METHODS: Twenty-seven patients underwent posterior stabilization of the cervical spine for degenerative instability resulting from myelopathy, fracture/dislocation, tumor, rheumatoid arthritis, and pyogenic spondylitis. Fixation included 1-6 motion segments (mean 2.2 segments). Transpedicular screws (3.5-mm diameter) were placed using 1 of 2 computer-assisted guidance systems and lateral fluoroscopic control. The intraoperative mean deviation of frameless stereotaxy was < 1.9 mm for all procedures. RESULTS: No neurovascular complications resulted from screw insertion. Postoperative computed tomography (CT) scans revealed satisfactory positioning in 104 (90%) of 116 cervical pedicles and in all 12 thoracic pedicles. A noncritical lateral or inferior cortical breach was seen with 7 screws (6%). Critical malplacement (4%) was always lateral: 5 screws encroached into the vertebral artery foramen by 40-60% of its diameter; Doppler sonographic controls revealed no vascular compromise. Screw malplacement was mostly due to a small pedicle diameter that required a steep trajectory angle, which could not be achieved because of anatomical limitation in the exposure of the surgical field. CONCLUSIONS: Despite the use of frameless stereotaxy, there remains some risk of critical transpedicular screw malpositioning in the subaxial cervical spine. Results may be improved by the use of intraoperative CT scanning and navigated percutaneous screw insertion, which allow optimization of the transpedicular trajectory.

Nerve sheath tumor surgery: case-guided discussion of ambiguous findings, appropriateness of removal, repeated surgery, and nerve repairs.

In this article the authors attempt to raise awareness of the pitfalls and controversial issues in nerve tumor surgery. In a case-guided format, examples of ambiguous findings, inappropriate tumor removal, repeated surgery, and nerve repairs are provided. The authors also discuss the need to establish a correct diagnosis preoperatively and to avoid the erroneous identification of malignant peripheral nerve sheath tumors (MPNSTs). They emphasize that not all of the principles of soft tissue sarcoma treatment protocols are applicable to MPNST. A situation of repeated surgery for supposedly malignant tumor is described, and an outline of the indications for, and an approach to, repair after lesion removal is given.

Inhalative and intravenous stimulation of soluble guanylate cyclase reduces pulmonary vascular resistance and increases cardiac output in experimental septic shock.

The effects of inhaled and intravenous application of a guanylate cyclase stimulator (BAY 41-8543) on pulmonary vascular resistance (PVR) and cardiac output (CO) were investigated in an experimental model of septic shock. Following induction of septic shock, anaesthetized pigs (n=31) were randomly place into two groups receiving different interventions. Animals in the first group received intravenous BAY 41-8543 (0.6 mg), inhalative BAY 41-8543 (6 mg) or a placebo. In the second group, the dosage of BAY 41-8543 was increased two-fold or combined with inhalation of nitric oxide (iNO). Intravenous and inhaled administration of BAY 41-8543 resulted in a significantly (P<0.05) reduced PVR and increased CO compared with the placebo. Increasing the dosage of BAY 41-8543 or combining it with iNO did not further decrease PVR. The results of the present study indicate that BAY 41-8543 effectively reduces PVR and increases CO in septic shock, through inhaled or intravenous routes of administration.

Reliability of transcardiopulmonary thermodilution cardiac output measurement in experimental aortic valve insufficiency.

BACKGROUND: Monitoring cardiac output (CO) is important to optimize hemodynamic function in critically ill patients. The prevalence of aortic valve insufficiency (AI) is rising in the aging population. However, reliability of CO monitoring techniques in AI is unknown. The aim of this study was to investigate the impact of AI on accuracy, precision, and trending ability of transcardiopulmonary thermodilution-derived COTCPTD in comparison with pulmonary artery catheter thermodilution COPAC. METHODS: Sixteen anesthetized domestic pigs were subjected to serial simultaneous measurements of COPAC and COTCPTD. In a novel experimental model, AI was induced by retraction of an expanded Dormia basket in the aortic valve annulus. The Dormia basket was delivered via a Judkins catheter guided by substernal epicardial echocardiography. High (HPC), moderate (MPC) and low cardiac preload conditions (LPC) were induced by fluid unloading (20 ml kg-1 blood withdrawal) and loading (subsequent retransfusion of the shed blood and additional infusion of 20 ml kg-1 hydroxyethyl starch). Within each preload condition CO was measured before and after the onset of AI. For statistical analysis, we used a mixed model analysis of variance, Bland-Altman analysis, the percentage error and concordance analysis. RESULTS: Experimental AI had a mean regurgitant volume of 33.6 ± 12.0 ml and regurgitant fraction of 42.9 ± 12.6%. The percentage error between COTCPTD and COPAC during competent valve function and after induction of substantial AI was: HPC 17.7% vs. 20.0%, MPC 20.5% vs. 26.1%, LPC 26.5% vs. 28.1% (pooled data: 22.5% vs. 24.1%). The ability to trend CO-changes induced by fluid loading and unloading did not differ between baseline and AI (concordance rate 95.8% during both conditions). CONCLUSION: Despite substantial AI, transcardiopulmonary thermodilution reliably measured CO under various cardiac preload conditions with a good ability to trend CO changes in a porcine model. COTCPTD and COPAC were interchangeable in substantial AI.

Surgical interventions for traumatic lesions of the brachial plexus: a retrospective study of 134 cases.

OBJECT: Surgical therapy for traumatic brachial plexus lesions is still a great challenge in the field of peripheral nerve surgery. The aim of this study was to present the results of different surgical interventions in patients with this lesion type. METHODS: One hundred thirty-four patients with traumatic brachial plexus lesions underwent surgery between January 1991 and September 1999. In more than 50% of the patients, injury was caused by a motorbike accident. Patients underwent surgery a mean of 6.3 months posttrauma. The following surgical techniques were applied: neurolysis for nerve lesions in continuity (27 cases), grafting for lesions in discontinuity (149 cases), and neurotization for root avulsions (67 cases). Sixty-five patients were evaluated for at least 30 months (mean follow up 42.1 months) after surgery. Function was graded using the Louisiana State University Health Sciences Center classification system. Only 2% of the patients had Grade 3 or better function preoperatively, increasing to 52% postoperatively. The effect of surgical measures on the functional results for different muscles were compared (supra- or infraspinatus, deltoid, biceps, and triceps muscles); the best results were obtained for biceps muscle function (57% of patients with Medical Research Council Grades M3-M5 function). Graft reconstruction yielded a better outcome than neurotization. Surgery within 5 months posttrauma clearly resulted in improved recovery of motor function compared with later interventions. Sural nerve grafts (monofascicular nerves) showed better results. CONCLUSIONS: The results of neurosurgical interventions for brachial plexus lesions are satisfactory, especially when the operation is performed between 3 and 6 months after trauma.

Anterior screw fixation in type II odontoid fractures: is there a difference in outcome between age groups?

OBJECTIVE: Optimal treatment of elderly patients with Type II odontoid fractures is controversial. Suggestions vary between conservative management and different types of early surgery. Recent data confirm that early surgery may be warranted because conservative treatment has a high rate of failure in the elderly. METHODS: We performed a case-control study of 27 patients with Type II odontoid fracture who were treated with anterior odontoid double-screw fixation at our institution. The aim of the study was to determine whether patients aged 70 years or older have a less favorable outcome than younger patients with this operative technique. Cases were defined as patients with Type II odontoid fracture aged 70 years or older. All patients younger than 70 years served as controls. RESULTS: There were 15 patients aged 70 years or older (Group 1) and 12 patients younger than 70 years of age (Group 2). Mean follow-up was 16.6 months. Mean interval between fracture and surgery was 10 days. All patients were treated with anterior odontoid screw fixation by use of two compression screws. Fusion rates were 73% in Group 1 and 75% in Group 2. Additional dorsal stabilization was performed in 13% of cases in Group 1 and 17% of cases in Group 2. Complications occurred in 20% of cases in Group 1 and 8% of cases in Group 2. The only death occurred in Group 1, leading to 7% mortality in this group. Neurological status at admission and after treatment was similar in both groups. Statistical analysis did not reveal significant differences between groups for the factors studied. CONCLUSION: Outcome after anterior odontoid screw fixation is not affected by patient age. Slightly higher rates of medical complications did not reach statistical significance. Because conservative management of odontoid fractures in the elderly has a high rate of failure, anterior stabilization for Type II odontoid fractures can be recommended.

Evaluation of traumatic cervical nerve root injuries by intraoperative evoked potentials.

OBJECTIVE: To evaluate intraoperative evoked potentials as a diagnostic tool in traumatic brachial plexus injuries. METHODS: Thirteen patients with traumatic brachial plexus injuries were investigated by intradural nerve root inspection (n = 28 roots) via cervical hemilaminectomy to assess or rule out nerve root avulsion from the spinal cord. Two to 8 weeks later, evoked potentials from neck and scalp were recorded after direct electrical nerve root stimulation close to the vertebral foramen during operative brachial plexus repair via an anterior (supraclavicular and infraclavicular) approach. Recordings were performed without and after full muscle relaxation. RESULTS: There was a clear relationship between the state of the root as documented by intradural root inspection and the result of intraoperative recording of evoked potentials: the absence of evoked muscle action potentials from neck muscles demonstrated a 100% sensitivity for anterior root lesions, whereas sensory evoked potentials from the scalp demonstrated a 100% sensitivity for posterior root lesions. Moreover, roots could be identified with preserved continuity that did not conduct, suggesting a nerve lesion in continuity. CONCLUSION: Intraoperative evoked muscle action potentials and sensory evoked potentials after electrical nerve root stimulation allow selective functional evaluation of anterior and posterior nerve roots in patients with traumatic brachial plexus injuries. The high sensitivity and reliability of this test obviate the need for additional diagnostic surgery.

Selective peripheral denervation for spasmodic torticollis: 13-year experience with 155 patients.

OBJECT: Botulinum toxin injections are the best therapeutic option in patients with spasmodic torticollis. Although a small number of patients do not benefit from such therapy, the majority respond well but may develop antibodies to the toxin after repeated applications. In those termed primary nonresponders, no improvement related to botulinum toxin has been shown. In patients in whom no response was shown and those in whom resistance to the therapy developed, selective peripheral denervation is a neurosurgical option. METHODS: Between June 1988 and August 2001, 155 patients underwent selective peripheral denervation. Surgery was performed at a mean of 8.5 years after the onset of symptoms (range 0.5-37 years). The mean age of the patients at the onset of dystonia was 39.7 years (range 17-77 years). For evaluation of results, patients' responses were assessed. Results were obtained in 140 patients in whom the follow-up period ranged from 3 to 124 months (mean 32.8 months): 18 reported complete relief of their symptoms, 50 significant relief, and 34 moderate relief; 19 noted only minor relief and the remaining 19 no improvement. The results differ substantially when compared with those previously demonstrated in patients who received botulinum toxin injections. Although 80% of the secondary nonresponders were satisfied with the result of surgery, only 62% of the primary nonresponders considered the operation helpful. There were no major side effects. The recurrence rate was 11%. CONCLUSIONS: The injection of botulinum toxin should be the first-choice treatment. If surgery is required, selective peripheral denervation provides the best results and has the fewest side effects compared with all surgical options.

Iatrogenic nerve injuries: prevalence, diagnosis and treatment.

BACKGROUND: Iatrogenic nerve injuries can result from direct surgical trauma, mechanical stress on a nerve due to faulty positioning during anesthesia, the injection of neurotoxic substances into a nerve, and other mechanisms. Treating physicians should know the risk factors and the procedure to be followed when an iatrogenic nerve injury arises. METHOD: This review is based on pertinent articles retrieved by a selective search in PubMed and on the authors' own data from the years 1990-2012. RESULTS: In large-scale studies, 25% of sciatic nerve lesions that required treatment were iatrogenic, as were 60% of femoral nerve lesions and 94% of accessory nerve lesions. Osteosyntheses, osteotomies, arthrodeses, lymph node biopsies in the posterior triangle of the neck, carpal tunnel operations, and procedures on the wrist and knee were common settings for iatrogenic nerve injury. 340 patients underwent surgery for iatrogenic nerve injuries over a 23-year period in the District Hospital of Günzburg (Neurosurgical Department of the University of Ulm). In a study published by the authors in 2001, 17.4% of the traumatic nerve lesions treated were iatrogenic. 94% of iatrogenic nerve injuries occurred during surgical procedures. CONCLUSION: A thorough knowledge of the anatomy of the vulnerable nerves and of variants in their course can lessen the risk of iatrogenic nerve injury. When such injuries arise, early diagnosis and planning of further management are the main determinants of outcome. If adequate nerve regeneration does not occur, surgical revision should optimally be performed 3 to 4 months after the injury, and 6 months afterward at the latest. On the other hand, if postoperative high resolution ultrasound reveals either complete transection of the nerve or a neuroma in continuity, surgery should be performed without any further delay. If the surgeon becomes aware of a nerve transection during the initial procedure, then either immediate end-to-end suturing or early secondary management after three weeks is indicated.