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This study analyses the correlation between the constriction in the substance of the median nerve in the carpal tunnel and distal motor latency, gender and age of patients with a carpal tunnel syndrome.In 82 patients (59 women and 23 men with an average age of 66.6 (41-89) years) with an electrophysiologically verified carpal tunnel syndrome undergoing open carpal tunnel release, the diameter of the median nerve was measured at the narrowest point of the nerve at the level of the constriction and the widest point of the nerve proximal to the constriction. The grade of nerve constriction was the ratio between the diameter at the level of the constriction and the widest diameter proximal to the constriction. Additionally, the distance from the distal wrist crease to the beginning of the constriction was measured. The grade of constriction was correlated with the patients' distal motor latency, gender and age.The diameter of the median nerve at the narrowest point of the constriction averaged 6.0 (SD 1.1) mm; the diameter at the widest point proximal to the constriction was 7.6 (SD 1.5) mm. The distance from the distal wrist crease to the beginning of the constriction averaged 17.6 (SD 3.7) mm. Grade of nerve constriction did not correlate with distal motor latency. However, there was a correlation between patient age and distal motor latency.The grade of nerve constriction cannot be estimated based on the severity of prolongation of distal motor latency. There is a positive correlation between the age of patients with a carpal tunnel syndrome and distal motor latency.ZIEL: Die vorliegende Studie untersucht, ob es eine Korrelation zwischen der Schwere der Stenosierung des N. medianus im Karpalkanal sowie dem Geschlecht und Alter von Patienten mit einem Karpaltunnelsyndrom und der distalen motorischen Latenz des Nervens gibt.Bei 82 Patienten (59 Frauen und 23 Männer mit einem Durchschnittsalter von 66,6 (41–89) Jahren) wurde bei elektrophysiologisch gesichertem Karpaltunnelsyndrom (KTS) während der offenen Karpaltunnelspaltung mit einer sterilen Schieblehre der Durchmesser des N. medianus an seiner engsten Stelle in Höhe der Stenose und an seiner breitesten Stelle proximal davon gemessen und dann ins Verhältnis gesetzt als Grad der Einengung. Der Grad der Einengung wurde mit der distalen motorischen Latenz (dmL) des N. medianus sowie dem Alter und Geschlecht der Patienten korreliert. Des Weiteren wurden die Messdaten von Frauen und Männern miteinander verglichen.Der Durchmesser des N. medianus an seiner engsten Stelle im Karpalkanal betrug im Durchschnitt 6,0 (SD 1,1) mm, an seiner breitesten Stelle proximal der Stenose durchschnittlich 7,6 (SD 1,5) mm. Die durchschnittliche Entfernung der Stenose zur Raszetta betrug 17,6 (SD 3,7) mm. Die distale motorische Latenz betrug im Durchschnitt 6,4 ms. Eine Korrelation zwischen dem Grad der Einengung des Nervens und seiner distalen motorischen Latenz fand sich nicht. Hingegen bestand eine positive Korrelation zwischen Alter und der dmL. Statistisch signifikante Unterschiede zwischen Frauen und Männern fanden sich weder für das Alter der Patienten, den Grad der Einengung des N. medianus, noch der distalen motorischen Latenz des Nervens.Aus der Verlängerung der distalen motorischen Latenz des N. medianus bei Karpaltunnelsyndrom lässt sich nicht auf den Grad der Einengung des Nervens im Karpalkanal schließen. Mit höherem Patientenalter findet sich die distale motorische Latenz des N. medianus bei KTS stärker verlängert.

Fibromyalgia syndrome (FMS) is characterized by chronic widespread pain and additional associated symptoms, such as fatigue, sleep disturbances and depressive moods. The pathophysiology of pain in FMS is unclear. In recent years, an involvement of the thinly myelinated A-delta and the unmyelinated C-nerve fibers has been reported in FMS patients. Independent research groups published consistent objective and multidimensional findings of damage to these small nerve fibers, such as disturbances of fiber function, electrical properties and morphological changes. All these alterations are not specific for FMS; however, they were described for the first time in subgroups of FMS patients. While the reasons for this small fiber pathology and its contribution to FMS pain are still unclear, a new research field has now been opened that will focus on uncovering the underlying pathophysiology. This review article summarizes these new findings and discusses the significance for the understanding of FMS.

It is not unusual for a neurological expert to have problems defining the precise anatomical location and the required objective proof of damage, especially if the medical history and the neurological report released by the clinic prove inadequate in terms of providing a reliable assessment. This may well result from somatoform disorders, dissociation, aggravation and simulation, as well as dissimulation and complex organic diagnostic findings. A range of standardised neurophysiologic procedures is available for the objective measuring of motor, vegetative and sensory systems; a brief summary of the most frequent occurrences is given here, along with their significance for appraising damage resulting from an accident. Target groups primarily include surgeons, orthopaedists, lawyers and insurance specialists. Structural improvements and measures to integrate immigrant doctors is essential.

Axon-reflex-based tests of peripheral small nerve fiber function including techniques to quantify vasomotor and sudomotor responses following acetylcholine iontophoresis are used in the assessment of autonomic neuropathy. However, the established axon-reflex-based techniques, laser Doppler flowmetry (LDF) to assess vasomotor function and quantitative sudomotor axon-reflex test (QSART) to measure sudomotor function, are limited by technically demanding settings as well as interindividual variability and are therefore restricted to specialized clinical centers. New axon-reflex tests are characterized by quantification of axon responses with both temporal and spatial resolution and include "laser Doppler imaging (LDI) axon-reflex flare area test" to assess vasomotor function, the quantitative direct and indirect test of sudomotor function (QDIRT) to quantify sudomotor function, as well as the quantitative pilomotor axon-reflex test (QPART), a technique to measure pilomotor nerve fiber function using adrenergic cutaneous stimulation through phenylephrine iontophoresis. The effectiveness of new axon-reflex tests in the assessment of neuropathy is currently being investigated in clinical studies.

The diagnostic work-up of peripheral neuropathies largely depends on neurophysiological investigations. Recently, progress in magnetic resonance imaging (MRI) has lead to new perspectives in the diagnostics of disorders of the peripheral nervous system (PNS). Experimental data show how MR neurography visualises axonal and demyelinating lesions of the PNS. In clinical use, difficult cases of focal nerve compression, traumatic or inflammatory lesions can be solved by the combination of MR neurography and neurophysiology. In particular, the localisation of nerve lesions can be improved by MR techniques. Furthermore, MR neurography enables new insights in the pathophysiology of neuropathies which will be shown for diabetic polyneuropathy.

The purpose of this retrospective study was the clinical and electrophysiological assessment of long-term results following surgical treatment of isolated axillary nerve lesions.10 patients, who underwent axillary nerve reconstruction using a nerve graft (80%) or a neurolysis alone (20%), with a follow-up period of 6.7 years (1.6-10.8 years) on average, were included in the study. In addition to the clinical examination, we examined reinnervation by electrophysiological methods and analysed their correlation to clinical results.30% of the patients had muscle strength of M5 and full active range of motion of 180°, 40% reached M4 and averaged 170° (80-180°), 30% of the patients M3 and 65° (40-90°). In patients with M5, muscle compound action potential averaged 40% of the contralateral side (21-62%), in patients with M4 36% (29-58%), and in patients with M3 7% (3-11%). Good results were associated with younger patient age, a short delay prior to the operation and neurolysis alone (indicated by intraoperative electroneurography).The good results confirm our treatment algorithm for isolated axillary nerve lesions by neurolysis alone or reconstruction with autologous nerve transplantation. Measurement of compound muscle action potential is a valuable addition to difficult clinical assessment, as its amplitude enables quantification of axillary nerve recovery.

Newly developed vagal stimulation probes permit continuous intraoperative neuromonitoring of the recurrent laryngeal nerve during thyroid resection. A complete signal loss indicates an interrupted nerve conductance. There are no other criteria so far which may serve as warning criteria for imminent nerve function impairment.The vagal stimulation probe V3 was used in 50 patients with thyroid resection (96 nerves at risk) and recorded during the complete operation (V3, adhesive tube electrode, bipolar needle electrode; Fa. Inomed, Teningen, Germany). The signal parameters amplitude, latency and thresholds of nerve conductance were compared before start-ing thyroid resection and after finishing thyroid preparation. The changes of these parameters were analysed.Complete signal loss was documented in 2 cases and vocal cord palsy confirmed laryngoscopically. Changes of the signal amplitude were seen in range from - 51% to + 243% after resection. The latencies (right vagal nerve 4.39 +/- 0.51 ms; left vagal nerve 6.78 +/- 0.75 ms) remained unchanged during the complete resection time. Lower threshold of nerve conduction varied from 0.5 to 2.5 mA, the upper threshold from 1.5 to 5.0 mA. All recorded changes of these parameters were not associated with laryngoscopic vocal cord disorders.Continuous intraoperative neuromonitoring permits an immediate problem solving reaction of the surgeon in the case of complete signal loss. The parameters signal amplitude, latency and conduction threshold cannot be applied as additional warning criteria for nerve function impairment during thyroid resection.

Facial paralysis may be treated by physical therapies with different therapeutic strategies and devices. Exercise therapy, electrotherapy, massage, lymph-drainage, biofeedback therapy are applied. Therapeutic strategies are based on the course of disease. It may be assumed that paralysis in moderate and moderate to severe courses of disease in acute lesions, moreover in chronic partial lesions and after gracilis muscle transplantation will benefit best from physical therapies. Course of disease depends on the degree of lesion, low-grade lesion will improve earlier and prognosis of motor recovery is good. To predict the course of disease in idiopathic facial paralysis nerve conduction studies can render valuable information by measuring the amplitude of the motor evoked potential in side to side comparison. In regard to scientific studies there is limited evidence that exercise therapy and biofeedback therapy improve the course of disease, motor performance recovers earlier and motor synkinesis are decreased. There is no evidence for electrotherapy to improve the course of disease nor to have any adverse effects. There is no relevant literature for massage and lymph-drainage in regard to facial paralysis. Every patient with facial paralysis--regardless to the degree of lesion--should receive a brochure with mimic exercises and instructions to support facial symmetry as basic intervention.

The relevance of subcutaneous transposition of the ulnar nerve in the therapy of cubital tunnel syndrome is still under debate. The aim of this study was to compare the results after decompression to additional transposition in cases of intraoperative luxation.A total of 54 cases after surgery of cubital tunnel syndrome between 2000 and 2006 were analyzed. Nerve transposition was performed in cases of intraoperatively apparent nerve luxation.Of the patients 12 were treated by decompression alone and 42 by additional subcutaneous transposition. There was no significant difference concerning symptom amelioration, usage properties of the hand, sensation impairment and duration of disability. Force measurements of grip strength and pinch strength revealed no significant differences between either hand in both groups. The 2-point discrimination ability of the 8th to 10th finger nerves was not significantly different between the groups either.Nerve transposition revealed no benefits in the treatment of cubital tunnel syndrome when performed in cases of intraoperative nerve luxation.

Neurological complications are among the most common in Mycoplasma pneumoniae (M.p.) infection and appear in up to 4,8 % of M.p.-infected patients . Whereas direct intracerebral infection can occur and often puts patients into critical, intensive care-requiring conditions, different forms of parainfectious autoimmune Guillain-Barré-syndrome (GBS) and Miller-Fisher syndrome (MFS) make up the most frequent neurological complications. M.p.-associated alterations of the blood count are common, and sometimes can take a dramatical course. We here report a 64-year-old female and a 53-year-old male patient who both suffered from severe parainfectious autoimmune neurological syndromes in combination with different forms of anemia, in the case of the first patient to a transfusion-requiring degree. With this report we would like to stress the importance to include M.p. in the diagnostic procedures in the case of inflammatory neurological syndromes, especially when combined with alterations of the blood count.

The purpose of this prospective, randomised and controlled study was to evaluate which kind of operative technique for treatment of cubital tunnel syndrome is favourable: subcutaneous anterior transposition or nerve decompression without transposition. This study included 66 patients suffering from pain and/either neurological deficits with clinically and electrographically proven cubital tunnel syndrome. 32 patients underwent nerve decompression without transposition, whereas 34 underwent subcutaneous transposition of the nerve. Follow-up examinations evaluating pain, motor and sensory deficits as well as motor nerve conduction velocities were performed three, nine and 24 months postoperatively. Irrespectively of operative procedures (simple decompression vs. subcutaneous anterior transposition) there were no significant differences between the outcomes of the two groups at either postoperative follow-up examination (p0.05).

A case of a mechanic and motorcyclist is reported who developed unilateral chronic exertional compartment syndrome of the flexor muscles in the forearm. After years of discomfort and medical check-ups, a subcutaneous fasciotomy of the superficial compartments of the flexor muscles in the forearm led to a complete relief of symptoms, which allowed the patient unrestricted activity.

Ulnar neuropathy at the elbow (UNE) is the second most common compressive neuropathy of the upper limb. Besides clinical evaluation, electrodiagnostic studies are usually applied to confirm the diagnosis. However, there are certain limitations to the diagnosis of UNE by electrodiagnostic studies. In a prospectively performed study we compared the diagnostic value of the electrodiagnostic parameters to the symptoms and the clinical parameters for different degrees of sensory and motor dysfunctions.Between 2001 and 2003, 38 patients (mean age 53.9 +/- 8.8 years, 19 men and 19 women) were treated at our institution for UNE. For 34 (89%) patients complete electrodiagnostic studies were performed and for 25 patients there was also an electrodiagnostic evaluation of the asymptomatic contralateral arm. According to the symptoms and clinical parameters (grip and pinch grip, two-point discrimination), the patients were assigned to three stages (mild, moderate, and severe). Electrophysiological measurements for each stage were compared with one another. The diagnostic value for each electrophysiological parameter was evaluated in comparison to the normal limits of the "Deutsche Gesellschaft für Neurologie (DGN)" and the "American Association of Electrodiagnostic Medicine (AAEM)".In the 34 symptomatic arms the mean values for motor nerve conduction were: conduction velocity (MNCV) = 41.2 +/- 11.6 m/s; velocity change above-to-below-elbow segment = 12.8 +/- 7.7 m/s; CMAP = 9224 +/- 5514 microV; dL = 3.24 +/- 0.82 mg. For the moderate stages of nerve compression (n = 11) the mean values are: MNCV = 42.5 +/- 12.7; velocity change MNCV = 13.2 +/- 6.8; CMAP = 11 890 +/- 4750; dL = 2.97 +/- 0.57; for severe nerve compression (n = 23): MNCV = 40.6 +/- 11.0; change MNCV = 12.7 +/- 8.3; CMAP = 7948 +/- 5358; dL = 3.37 +/- 0.8. The difference for each parameter between the symptomatic and asymptomatic contralateral arm was statistically significant (p0.05) as it was for the difference of the parameters of the group with severe nerve compression in comparison to the asymptomatic arm. In the comparison of the moderate stage group with the asymptomatic arm there was only a significant difference for MNCV and there was no significant difference between the moderate and the severe group. In our study the calculated sensitivities for the electrodiagnostic studies were 76% for all symptomatic arms, 64% for the moderate group, and 83% for the severe nerve compression group. In all patients the MNCV was the most sensitive parameter.Electrodiagnostic studies were only able to reveal 3/4 of all patients with an affection of the ulnar nerve and only 2/3 of the patients with a moderate stage of ulnar nerve compression. Although important for the further therapy, a differentiation between a moderate and severe degree of nerve compression was not possible.

Regardless of their specific physico-chemical properties and chemical structures, all local anaesthetic agents block neuronal voltage-gated sodium channels, and thus suppress conduction in peripheral nerves. Since these ion channels ubiquitously appear in excitable membranes, systemic accumulation of local anaesthetic agents may affect the functional integrity of these structures. Clinically, local anaesthetic-induced systemic toxicity results in central nervous and cardiovascular malfunction. With regard to CNS toxicity, symptoms which are largely drug-independent appear in a characteristic biphasic sequence. Nevertheless, the plasma levels necessary to provoke these symptoms are to a large extent agent-specific. Initially, these toxic mechanisms are due to a selective blockade of cortical inhibitory neurons, which enables the formation of seizure potentials within subcortical structures. With high cerebral drug levels, however, excitatory neurons are also increasingly blocked, resulting in coma, apnoeic episodes and circulatory failure. Direct cardiac effects of local anaesthetics can be divided into (i) stereospecific inhibition of intracardial conduction and (ii) unspecific inhibition of myocardial energy supply and ion channels. The corresponding spectrum of symptoms is not uniform and may range from extreme bradycardia, (malignant) ventricular arrhythmia to refractory cardiac arrest. Local tissue toxicity has to be strictly delimited from systemic toxicity and allergies, respectively, which are mainly caused by aminoester agents. Local anaesthetics may cause neuronal and striated muscle injury at the site of injection. With regard to (central) neurotoxicity, "transient neurologic symptoms" and "cauda equina syndrome" have been increasingly recognised. However, the clinical relevance of local anaesthetic-induced myotoxicity is still controversly discussed. In order to avoid systemic accumulation of local anaesthetic agents, several safety procedures have to be considered during the application of these drugs. The treatment of systemic toxicity is strictly dependent on the expression of symptoms. However, hypoxia and acidotic episodes must be avoided and must be treated aggressively.

Handsurgeons are normally more interested in clinical tests evaluating sensory and movement disorders of hand. Since these are often unprecise and require a cooperative (and intelligent) patient, neurologists and neurosurgeons prefer precise diagnostic procedures. For this reason they use electrophysiological techniques to evaluate and localize peripheral nerve lesions, i.e. electromyography, sensory and motor nerve conduction velocity and somatosensory-evoked potentials (SEP), by which most nerves of the arm and hand (median, ulnar and radial nerves including their major branches) can be easily assessed. Insufficient technique (submaximal stimulation, no temperature control, stimulation of a neighbouring nerve) and mis- or overinterpretation are sources of error, which can best be avoided when the diagnosis is made in context with the clinical picture--especially when the surgeon is familiar with electrophysiological techniques.

During nerve surgery, electrodiagnostic methods are applied to assess the availability and viability of nerve fibers and to adjust operative measures accordingly. The validity of this procedure is verified by histology and by the outcome of the operation. This paper explains the techniques of intraoperative nerve action potential (NAP) and somatosensory evoked potential (SEP) recording, how to interpret the electrodiagnostic results, and describes both the special features and the limitations of the methods. We found reliable results of neurography, detecting the presence or absence of spontaneous nerve regeneration across a lesion in continuity months before the reinnervation reached its final target. Based on our results, we suggest that NAP recording of the exposed nerve can widely prevent unnecessary nerve or fascicle resection. Besides this important indication, the nerve function evaluation was successfully used in nerve surgery whenever the quality of the nerve parenchyma was crucial to the operative management. Further indications such as evaluating brachial plexus lesions and the condition of nerve roots, judging the proximal coaptation site in nerve reconstruction, tracing the site of a nerve lesion and identifying the pathophysiology of nerve malfunction are exemplified. Intraoperative nerve conductivity testing should not be considered as a replacement of but rather as a complement to preoperative clinical, electrophysiological and imaging evaluations and a thorough intraoperative morphological examination.

Summary. Apart from clinical findings, the diagnosis of compression syndromes of peripheral nerves is based on electrophysiological investigations. This includes the determination of nerve conduction velocities, distal motor latency and electromyography, which gives a qualitative indication of the condition of nerves and their related muscles. In the 1980s, new methods were developed for quantifying the diagnoses of nerve lesions and their recovery. Due to the development of new software, we can now carry out these investigations with commercial equipment. The macro-EMG and the motor-unit-estimation give information about the size and number of activated motor units of muscles. One needs a special needle which derives single-fibre- and macro-potentials for recording of the macro-EMG. The single-fibre-potential is used for triggering. The motor-unit-estimation represents a non-invasive method to determine the approximate number of motor units. Multiple point stimulation of the nerve is used to determine action potentials which are registered by surface electrodes. Afterwards, the medians of amplitudes and areas of motor unit action potential are defined and must be divided by the corresponding value of maximal compound muscle action potential for estimating motor units. In this way, the extent of nerve damage can be determined exactly. Additionally, a post-operative follow-up is possible. Furthermore, these methods give information about regeneration processes after nerve damage and their recovery after reconstruction and transplantation. From our point of view, these methods should be included in investigation routinely.

A 71-year-old man with cryoglobulinemia associated with severe symmetrical sensorimotor polyneuropathy was successfully treated with intravenous immunoglobulin (IVIG) and a corticosteroid. Within 2-3 months, he developed distal motor and sensory deficits and burning feet deteriorating after cold exposure. On examination, symmetric hypesthesia and hypalgesia were found along with bilateral loss of vibration and position sense, loss of ankle jerks, and paralysis of the pretibial muscles with step-page gait. The laboratory exam revealed elevated cryoglobulin levels and reduced complement C4. Nerve conduction studies were consistent with a severe axonal sensorimotor polyneuropathy. Sural nerve biopsy showed chronic neuropathy with an acute component. The patient underwent a combined treatment with prednisolone (initially 100 mg) and intravenous immunoglobulin. His condition markedly improved after almost a year of treatment. Unfortunately, the treatment with intravenous immunoglobulin had to be interrupted due to an allergic reaction after the sixth application.

Acute compartment syndrome of the leg is to be regarded as a traumatological emergency. Most specialists already agree that only a timely operative decompression of the afflicted compartment can prevent serious tissue damage. What still remains subject to discussion, however, is the precise tissue pressure above which the operation becomes imperative. Experimental human studies focusing on tissue pressure and muscle oxygenation have not yet been carried out. It was thus the aim of the present study to analyze oxygen partial pressure of the anterior tibial muscle and peroneal action potential in a model compartment syndrome in man.In 22 healthy, normotensive volunteers, constant pressure values from 0 to 100 mmHg were induced in the anterior tibial muscle with antishock trousers. Over a period of up to 6 h measurements were made of (1) tissue pressure, (2) intramuscular oxygen partial pressure (pO2), and (3) muscle response potential (MRP) of the n. peroneus profundus by electroneurography.We achieved a 97.7% (Q25%/Q75%: 89.2/99.8) transfer of the pneumatic pressure to the lower leg. Already at intramuscular tissue pressures of 30-40 mmHg, hypoxia and reduction of MRP appeared. A reduction of the MRP to zero and pO21 mmHg was observed from a pressure of 50 mmHg. Tissue pressure values of over 75 mmHg resulted almost without exception in anoxia of the muscle.Even under normal perfusion conditions, already slight increases in pressure of above 30 mmHg lead to reduced tissue oxygenation and neural function. We have to consider that with additionally traumatized muscle the ischemic tolerance is markedly reduced and due to unknown influences such as local vasoreactivity and capacity of autoregulation the nutritive perfusion cannot be determined. In the case of a severely injured muscle, to be on the safe side decompressive fasciotomy should therefore be carried out if pressure values remain above 30 mmHg.

The aim of this study was to examine sensitivity and specificity of Durkan test in 54 patients with carpal tunnel syndrome confirmed by electrophysiological testing, as compared to a control group of 54 patients without clinical signs of the syndrome. Sensitivity and specificity of Durkan test alone, as well as in combination with Phalen test and Hoffmann-Tinel test, were determined. The sensitivity of Durkan test was 0.87, its specificity was 0.96. The sensitivity of Phalen test was 0.85 with a specificity of 0.96. It was discovered that the combination of Phalen with Durkan test achieved a sensitivity of 0.94 and a specificity of 0.96, thus equalling the respective values for electrophysiological testing (nerve conduction velocity, electromyography) which so far is regarded as the golden standard diagnostic test for carpal tunnel syndrome. If Hoffmann-Tinel test is included as a further clinical parameter, then both sensitivity and specificity reach 0.96. This study, therefore, raises the question of whether costly electrophysiological testing is in fact necessary before surgery for carpal tunnel syndrome, when the clinical tests have already proven positive.

The functional and cosmetic results after hypoglossal-facial nerve anastomosis (HFA) have primarily been described using a subjective grading system of good, fair, or poor. To obtain more objective results, the postoperative mimic function was investigated using a combination of clinical and electrophysiological methods.A total of 29 patients with hypoglossal-facial anastomosis were evaluated using a standardized questionnaire and the Stennert's paralysis index as clinical scoring system and electroneurography (NMG/ENoG) and electromyography (EMG) as electrophysiological assessments.Twenty-six of 29 patients (89%) judged their own facial function as very good or good, and three as poor. Under resting tone conditions, no patient showed a difference between palpebral fissures (3 mm), an ectropium, a substantial loss of nasolabial fold, or a drop of angulus oris (3 mm). With attempted movement, the lid closure was complete in 76% of patients, and the cornea was lid-covered in 100%. Sixty-seven percent of the patients were able to whistle. The second upper incisor was visible (full width) in 19%. No patient could frown sufficiently or expose the upper and lower canine teeth. The mean Stennert's score decreased from 9 to 4 after surgery. The relative amplitudes of the NMGs were increased in patients with low clinical indices. Patients with a complete eye closure showed a higher density of EMG patterns in their orbicularis oculi muscles. No significant differences for clinical or electrophysiological parameters could be observed based on age, sex, or time point of operation.Combining the Stennert's paralysis index with NMG and EMG allows a more objective assessment of functional and cosmetic results after HFA.

Lesions of peripheral nerves are serious complications associated with total hip replacements. Prognostic factors and treatment concepts have not been sufficiently defined. Improvements can occur spontaneously. This study aimed to evaluate risk factors and diagnostic aids, such as the velocity of nerve conduction (VNC) and electromyography (EMG). Furthermore, the effect of prognostic factors as well as conservative and invasive therapeutic measures on the regression of clinical symptoms was examined.From 1990 to 1996 1833 patients underwent total hip replacement. 1447 procedures were primary total hip replacements and 386 were revisions. 14 femoral nerve lesions (0.8%), 7 sciatic nerve lesions (0.4%) and 8 peroneal nerve lesions (0.4%) occurred. 19 patients were examined clinically, electromyographically and by means of VNC, 10 patients only clinically. In 5 patients a neurolysis was performed within the first postoperative year. All 29 patients underwent a recall examination in 1997 to evaluate the development of the clinical symptoms and if possible, VNC and EMG were performed.Of the 7 patients with sciatic nerve lesions, two were free from symptoms at the time of recall, two still complained about residual symptoms and two showed no improvement of the lesion. One patient did not appear for follow-up. Of the 8 patients with peroneal nerve lesions, five were free from symptoms at the time of their recent examination, two showed residual symptoms and one patient did not appear. Of the 14 patients with femoral nerve lesions, four had recovered completely, eight showed residual symptoms, one patient did not improve and one patient had died.Prognostic statements regarding the improvement after nerve lesions are possible only to a limited degree. However, it was found that the motor function tended to recover earlier than sensibility. We could not determine with clinical evaluations why some patients showed an improvement of their lesion while others did not. As well no clear correlation between the EMG and VNC results and the recession of the symptoms could be established.

The success of surgical treatment of carpal tunnel syndrome depends largely on correct diagnosis. Nerve conduction studies are usually recommended, especially in cases where history and clinical signs are not very clear. The aim of this study is to show whether nerve conduction studies are helpful in confirming the diagnosis. Fifty-two cases of carpal tunnel decompression (39 patients, 13 male, 26 female, mean age 54 years) were included in the study. Prior to surgery, all patients underwent standardized nerve conduction studies. One patient who developed RSD was excluded. In 33 cases the history was typical for carpal tunnel syndrome (Phalen 1966). The surgical result was classified excellent in 67% and good in 33%. Nerve conduction studies had failed to confirm the diagnosis in five cases, although duration as well as severity of symptoms did not differ from the other cases. In 18 cases the patients' history was considered atypical. Nerve conduction studies indicated carpal tunnel syndrome in 89%. The result of median nerve decompression was satisfactory in 78% (excellent in 45% and good in 33%) and unsatisfactory in 22% of the cases. Notably patients with unsatisfactory results had positive nerve conduction studies. The Phalen and Hoffmann-Tinel testing produced no false-positive results in these cases. General analysis showed that age, severity and duration of symptoms did not significantly influence the result. However, patients with atypical symptoms had a higher incidence of radiological evidence of cervical spondyloarthritis (50 versus 30% in patients with typical symptoms). The results of our nerve conduction studies indicated a sensitivity of 85% and a specificity of 92%, comparable favourably with other reports. We conclude that in patients with classical symptoms nerve conduction studies are not absolutely necessary. However, when symptoms are atypical the diagnosis cannot be based on nerve conduction studies alone. The false-positive results delivered by the nerve conduction studies may be explained with the "double crush" theory, since cervical spondyloarthritis prevailed in patients with atypical symptoms.

Most for polyneuropathies present in a uniform, distally accentuated, rather symmetrical pattern, although asymmetric or multifocal distributions occur. The main feature of diagnosis is the history of development and the neurological clinical examination. Neurophysiologic studies, mainly nerve conduction studies (motor and sensory), reflex studies and electromyography are very accurate, but unspecific tools in order to establish the diagnosis of polyneuropathies, define special electrophysiologic features and can also reveal undetected (subclinical) lesions. For clinical purposes most neuropathies can be divided according the nerve conduction studies in axonal, demyelinating and mixed types. In recent years additional electrophysiological features as conduction block have appeared and are still under discussion. The etiology of polyneuropathy has to be determined in each patient with scrutinity. Additionally to general diseases (e.g. diabetes), common toxins (e.g. alcohol), concurrent medication (e.g. some cytostatic drugs) also immunologic (e.g. vasculitis) and hereditary factors have to be considered. A nerve biopsy is only indicated after a thorough consideration of electrophysiology and ancilliary findings. This applies in particular to hereditary neuropathies, where genetic testing has become a highly reliable test replacing biopsy.

Electrodiagnostic techniques used in an EMG-Laboratory and the diagnostic value in focal mononeuropathies are presented. The electrodiagnostic techniques include nerve conduction studies and needle electrode examination. Measurement of distal latency, amplitude, conduction velocity and the finding of focal conduction block may localize the focal character of the mononeuropathy. The needle electrode examination gives further information about distribution, extent, activity, or chronicity of the disease, especially in cases with axonal injuries. Some normal electrodiagnostic patterns are presented, accompanied by some illustrative pathological cases.

To test the hypothesis that the efficacy of local anaesthetics to block nerve conduction is related the time of day (TOD) of drug application, we retrospectively analysed data from previous experiments on tachyphylaxis. During the course of these experiments, as a measure of drug efficacy we determined the minimal blocking concentration (c(m)) of bupivacaine in rabbit aortic nerves at several TODs. The special in situ preparation used permitted study of local anaesthetic pharmacodynamics without the influence of pharmacokinetics, making it possible to investigate the chronopharmacodynamics of these drugs by relating c(m)s to the respective TODs of their measurement.In 43 New Zealand rabbits anaesthetised with urethane, the aortic nerve was dissected and partly placed in a double-lumen perfusion chamber (Fig. 1A), which was continuously perfused with tyrode solution or bupivacaine. Spike activity was continuously recorded by bipolar platinum-iridium electrodes caudad to the chamber for control and cephalad for registration of blocking effects. As a measure of drug efficacy, by increasing the bupivacaine concentration stepwise we determined the smallest concentration that blocks spike activity i.e., c(m). After each determination bupivacaine was rinsed off to confirm intact nerve function (Fig. 18).Forty-nine determinations of bupivacaine c(m) were performed between 12:25 p.m. and 2:35 a.m. Data were pooled into groups of 2 h (Fig. 2). There was no significant difference between groups (ANOVA). In particular, c(m) at 3:00 p.m. was not lower than at 11:00 p.m., times at which local anaesthetics have been found to be most and least effective, respectively.The c(m) of bupivacaine, and thus its efficacy to block nerve conduction, does not depend on TOD of drug application. Therefore, it is suggested that chronopharmacodynamics does not play an important role in the well-known circadian rhythm of the action of bupivacaine and probably of local anaesthetics in general.

Quantitative assessment of thermal and pain sensitivity (Marstock method on a SOMEDIC Thermotest, Somedic AB Stockholm, Schweden) was made and the function of autonomic nervous system (sympathetic skin response and R-R interval variation) indicating the function of small nerve fibres (A-delta and C) was determined in 44 patients with symptoms of the presumed sensory neuropathy. The function of the large nerve fibres was evaluated by the classic nerve conduction study. The methods of small nerve fibres evaluation exhibited greater sensitivity as the classic nerve conduction study. The dysfunction of small nerve fibre function was morphologically proved by sural nerve biopsy.

Anterior transposition of the ulnar nerve in cubital tunnel syndrome requires ligation of the segmental epineural vessels over 8 to 10 cm in order to free up and mobilize the nerve along its new course. As a result, the blood supply of ulnar nerves already compromised by entrapment is likely to be harmed even more. For the past three years we chose to perform simple decompression of the nerve with or without external/internal neurolysis on 33 patients (34 arms). After a follow-up time of six months to three years (mean 12 months), the outcome was evaluated by complete examination of hand function and by electrophysiologic studies. Four patients were excluded from the analysis due to short follow-up times. Four underwent decompression for mild entrapment symptoms, six for moderate symptoms, and 19 for severe symptoms. The functional outcome was rated as excellent in 26.7% (eight patients) and as good in 33.3% (ten patients). In group 3 (severe entrapment symptoms), seven patients (23.3%) showed moderate results and in four patients (13.3%) the outcome was poor. Considering that most of our patients had severe entrapment with advanced muscle atrophy, the overall outcome of decompression was satisfactory.

Three adult siblings had atypical progressive spinal muscular atrophy of the limb-girdle type, predominantly sensory polyneuropathy and cerebellar ataxia. Hexosaminidase A and B activity was profoundly decreased in serum, leukocytes and cultured fibroblasts. GM2-gangliosidosis, variant O (Sandhoff disease) was diagnosed. Mechano-allodynia was the presenting symptom in two of the patients. After 50 years of disease evolution, the patients led an independent life and were intellectually normal. The literature on the adult form of GM2-gangliosidosis is reviewed.

Laboratory testing in 10 "Walliser Schwarzhals"-goats included red and white blood cell count, electrolytes, liver enzymes, trace elements and urinalysis, protein determination and cell count of the cerebrospinal fluid (CSF) was also performed. Electrodiagnostic testing included electromyography (EMG) of the head and spinal muscles, motor nerve conduction velocity (MNCV) of the right and left peroneal nerve, brainstem auditory evoked potentials (BAEP) and electroencephalography (EEG). MNCV of the peroneal nerve was 72 +/- 9.24 m/s. Latency and amplitude of the BAEP for P1 was 2.15 +/- 0.08 ms respectively 2.23 +/- 0.7 microV and for P5 5.09 +/- 0.15 ms respectively 0.68 +/- 0.24 microV. P2 (3.2 +/- 0.14 ms/1.37 +/- 0.32 microV) and P3 (3.9 +/- 0.13 ms/0.84 +/- 0.14 microV) were equally distributed between P1 and P5. Whereas the results of EMG and BAEP were similar to those of other species, the electroencephalographic findings consisted of three different patterns depending on duration and depth of isofluran anesthesia. Pattern I had a rhythmic high amplitude (80 microV) and low frequency (1-2 Hz) pattern with aperiodic intervals of relative electric silence. Pattern II was characterized by increased duration of HALF (150 microV), associated with spindles of low amplitude (20-30 microV) and high frequency (10 Hz). Pattern III had generalized delta-activity of high amplitude (70-200 microV). All the results are discussed briefly.

The history of clinical application of electromyographic and electroneurographic techniques is not even 60 years old. For a long time the clinicians' need could not be fulfilled, due to the imperfection of the electronic equipment. Nowadays, electromyography and electroneurography are established methods not only for the diagnosis of neuromuscular disorders, but since the recording of cortical and spinal evoked potentials has been introduced, diseases of the central nervous system lie also within its scope.

For a large scaled test 52 patients with anterior transposition of the ulnar nerve and 62 patients with elbow injuries were examined by questionnaire, physical examination and electroneurography. In conformity with existing literature 24 patients out of 52 suffering from cubital tunnel syndrome had an elbow trauma previously. To our great surprise in seven patients out of 46 with elbow injuries a cubital tunnel syndrome could be found for the first time. The cubital tunnel syndrome appears to be a frequent complication of elbow injuries. Besides the well known fractures of the medial epicondyle and pericondylar fractures leading to cubital tunnel syndrome, in our study fractures of the head of the radius and processus coronoideus were found quite often. Patients having typical anamnesis and complaints should be checked by electroneurography in order to permit a quick operation and to prevent incurable damages of the nerve. The diagnosis leading to operation of the elbow should however be made with greatest care. In case the operation is unavoidable, the ulnar nerve should be thoroughly checked and anterior transposition should be carried out.

Extraarticular, predominantly neuromuscular, factors are thought to contribute to the development of osteoarthritis. With increasing age, changed temporal dynamics of motor reflexes and reduced muscular force may affect the efficacy of neuromuscular protection of the knee joint. In three experimental studies conducted with osteoarthritis patients and healthy controls, no difference was found in monosynaptic reflex times and latencies of somatosensory evoked brain potentials. Muscular force was generally diminished in the patients, with the most prominent reduction during coxal abduction. Osteoarthritis patients had marked nociceptive hyposensitivity, but no difference was seen in fast conduction afferent systems. In an animal study with high locomotion load, interruption of articular afferent nerve fibers led to a precipitation of cartilage degeneration. It is concluded that minor extraarticular functional deficits acting over time, probably support and aggravate the development of osteoarthritic changes.

Sensory neurography is a diagnostic aid in the evaluation of peripheral nerve function. Up to now, the measurement of the orthodromic nerve conduction velocity has been supposed to be the only valuable method in veterinary medicine. However, there is always a certain risk because the procedure requires immobilized animals. In this article, the measurement of the sensory antidromic nerve conduction velocity in the superficial radial and the superficial peroneal nerve of the dog is described as an alternative method. Usually, this procedure can be done without immobilisation or general anesthesia. Thus, the antidromic nerve conduction velocity represents a valuable screening method for evaluation of peripheral nerve function. In dogs without changes in laboratory values and without signs of neurologic disease, the nerve conduction velocity is 52.5 +/- 6.6 m/s (mu +/- s) for the superficial radial nerve and 49.4 +/- 5.7 m/s (mu +/- s) for the superficial peroneal nerve.

Peripheral and central mechanisms involved in generation, modulation and perception of pain are discussed. Lesions of peripheral nerves are a particular cause of pain, which has to be recognized as such, as it requires specific therapeutic measures. Emphasis is put on the role of ephaptic transmission.

In 18 healthy persons aged 22-71 years and 17 patients suffering from clinically defined polyneuropathy the NCV of the sural nerve was measured both by antidromic technic recorded by surface electrodes and by orthodromic technique recorded by needle electrodes. Stimulation was done by bipolar surface electrodes in all cases. The skin temperature was warmed up to the minimum of 35 degrees C. The results showed in both groups a highly significant correlation of the NCV measured by antidromic and orthodromic technique. With increasing age the NCV decreased, but this was not significant. In all healthy persons sensory nerve potentials could be recorded with both techniques. In polyneuropathy missing of sensory potentials was higher in patients investigated by the antidromic technique than by orthodromic. For clinical practice measurement of NCV in sural nerve using antidromic technique should be preferred because of its simpler and faster achieving, its lower discomfort for the patient and avoiding risk of infection. However in case of missing nerve potentials, orthodromic investigation using needle electrodes for recording should be added.

The "Duplizitätstheorie" of Meyer zum Gottesberge (1948) states that signal processing takes place at low sound intensities on the nerve fibers of the outer hair cells, whereas at high sound intensities on the nerve fibers of the inner hair cells. The discovery of oto-acoustic emissions by Kemp (1978) makes a modification of the "Duplizitätstheorie" necessary. The outer hair cells are supposed to be motor-drives final control elements to enhance the sensitivity of inner hair cells. Thus outer hair cells do not serve for the direct transmission of information in the sense of neural coding. Signal processing takes place at all intensities exclusively on the nerve fibers of the inner hair cells.