Disc replacement with the SB Charité endoposthesis - experience,preliminary results and comments after 35 prospectively performed operations

Aim of this prospective study was an investigation concerning the indication for the implantation of an artificial disc endoprosthesis and the rating of this operation. METHOD: 35 patients with 11 bi- and 24 monosegmental implanted disc endoprosthesis were observed over an average follow-up of 14.7 months. Indications for the operation were: unsuccessful, orthopedic conservative treatment > 6 months, segmental pain, age < 45 years, evidence of a radiologic (MRI) demonstrable mono- or bisegmental disc degeneration with or without disc prolabation, exclusion of psychogenic disease and positive preoperative, diagnostic measures. RESULTS: The average stay in the hospital was 16.8 days (preoperative: 4.3 days), the average operation time 85.5 minutes, the average blood loss was 125 ccm. 23 patients were operated in L 5 / S 1, 20 in L 4 / 5 and 2 in L 3 / 4. NSAR was given in 33 patients preoperatively, opiates in 2 further patients, postoperatively NSAR was necessary in 5 patients, opiates in 2 patients. The preoperative angle of lordosis (L 1 - S 1, n = 25) was changed from 35.6 degrees to 42.6 degrees (20,2 %), the segmental angle from 19 degrees to 30 degrees (57.5 %). CONCLUSION: The implantation of the artificial disc was followed by a good pain relief in patients suffering from a mono- or bisegmental disc degeneration. In patients with a facett joint arthrosis and elderly patients > 45 years this method cannot be used, the indication in patients with failed back surgery syndrome cannot be estimated yet. Improvements of the instrumentation and the discussion in the case of revisional operations are mandatory.     

Electrophysiological brainstem testing in the diagnosis of reversible brainstem ischemia

The aim of this study was to evaluate the sensitivity of multimodal electrophysiological brainstem testing in the diagnosis of clinically suspected reversible ischemic deficits of the brainstem compared with diffusion weighted MR imaging. We investigated 158 consecutive patients presenting with signs of acute brainstem dysfunction. Serial electrophysiological brainstem tests including masseter reflex, blink reflex, masseter inhibitory reflex, AEP, MEP, EOG and the oculoauricular phenomenon were applied. In 14 of the 158 patients neurological deficits resolved in less than 24 hours, which was suggestive of a transitory ischemic attack (TIA), 19 patients had brainstem signs for more than 24 hours but less than 1 week, suggestive of a reversible ischemic neurological deficit (RIND). Electrophysiological data indicated acute functional brainstem lesions in 54,5 % of patients with transient clinical brainstem impairment. Lesion detection rate was significantly higher when combining electrophysiological data and MRI (60,4 %) than using acute brainstem abnormalities in diffusion weighted MRI alone (39,4 %). We conclude that diffusion weighted MRI and electrophysiological brainstem testing are complimentary sensitive indicators of acute brainstem lesions in patients with reversible neurological deficits. Correct identification of brainstem ischemia influences the therapeutic regimen and may improve patient outcome. Received: 5 November 2001 Received in revised form: 28 January 2002 Accepted: 1 February 2002     

How does attention attenuate target-distractor interference in vision?. Evidence from magnetoencephalographic recordings

This study used magnetoencephalographic and electroencephalographic recordings to investigate the neural mechanisms that underlie the attentional resolution of ambiguous feature coding in visual search. We addressed this issue by comparing neural activity related to target discrimination under conditions of more versus less feature overlap between the target and distractor items. The results show that increasing feature overlap leads to a focal enhancement of neural activity in ventral occipito-temporal areas, consistent with the larger need to attenuate distractor interference. Furthermore, the results suggest that distractor attenuation proceeds as a stepwise operation, with different spatial locations containing interfering features being suppressed successively. These findings support theories of visual search that emphasize location-based attentional selection as a key mechanism in resolving ambiguous feature coding in vision.     

Assessment of brainstem function in Chiari II malformation utilizing brainstem auditory evoked potentials (BAEP), blink reflex and masseter reflex

Brainstem dysfunction was evaluated in 67 patients with myelomeningocele and Chiari II malformation using brainstem auditory evoked potentials (BAEP), blink reflex (BR) and masseter reflex (MR). Signs and symptoms related to Chiari II malformation were observed in 18 patients while 49 patients had normal brainstem findings. BAEP and BR showed a higher sensitivity of brainstem involvement than MR (BAEP=1.0, BR=0.83, MR=0.50). BR, and in particular, MR were of higher accuracy (BR=0.52, MR=0.72) than BAEP (0.39) in separating patients with brainstem signs and symptoms related to Chiari II malformation. We feel that this is due to anatomic and physiologic peculiarities of the brainstem structures mediating BR and MR. Our results suggest that brainstem reflexes can support the decision of further treatment.     

New classification of recommendations for forensic assessment of patients with scoliosis

In 1977, for the first time, a recommendation for the expert evaluation of scoliosis-sufferers was given out. On the basis of this a new classification followed, which takes into consideration modern orthetics and new operative procedures. Unchanged are the classifications of incapacity to work with regard to decreasing lung capacity. The levels of vital capacity are still the main factor for determining lung capacity.     

Eine faktorielle Studie von 6 Interventionen zur Vermeidung von Übelkeit und Erbrechen nach Narkosen

BACKGROUND: Untreated, one third of patients who undergo surgery will have postoperative nausea and vomiting. Although many trials have been conducted, the relative benefits of prophylactic antiemetic interventions given alone or in combination remain unknown.METHODS: In a randomized, controlled trial of factorial design, 5,199 patients at high risk for postoperative nausea and vomiting were randomly assigned to 1 of 64 possible combinations of 6 prophylactic interventions: 1) 4 mg of ondansetron or no ondansetron; 2) 4 mg of dexamethasone or no dexamethasone; 3) 1.25 mg of droperidol or no droperidol; 4) propofol or a volatile anesthetic; 5) nitrogen or nitrous oxide; 6) remifentanil or fentanyl. The primary aim parameter was nausea and vomiting within 24 h after surgery, which was evaluated blindly.RESULTS: Ondansetron, dexamethasone, and droperidol each reduced the risk of postoperative nausea and vomiting by about 26%, propofol reduced the risk by 19%, and nitrogen by 12%. The risk reduction with both of these agents (i.e., total intravenous anesthesia) was thus similar to that observed with each of the antiemetics alone. All the interventions acted independently of each other and independently of the patients' baseline risk. Consequently, the relative risks associated with the combined interventions could be estimated by multiplying the relative risks associated with each intervention. However, absolute risk reduction was a critical function of patients' baseline risk.CONCLUSIONS: Because antiemetic interventions are similarly effective and act independently, the safest or least expensive should be used first. Prophylaxis is rarely warranted in low-risk patients, moderate-risk patients may benefit from a single intervention, and multiple interventions should be reserved for high-risk patients.     

Erfahrungen mit der Anwendung der Crutchfield-Klammer

Zusammenfassung Anwendungsweise und Anzeigestellung für den Gebrauch der Kopfklammer nach Crutchfield bei Halswirbelverletzungen werden an Hand von Beispielen beschrieben. Gegenüber dem Dauerzug mittels der Glissonschlinge hat die Crutchfield-Klammer den Vorteil einer weit besseren Verträglichkeit und Ruhigstellung, sowie Essenserleichterung. Ja nach der Höhe der vorliegenden Verletzung werden verschieden große Zuggewichte benötigt. Die Sicherung des erzielten Korrekturergebnisses erfolgt in der Regel durch nachfolgenden Schanzschen Watteverband, wobei ältere Personen zur späteren Wiederkehr der Wirbelverschiebung infolge schlechterer Regenerationsbedingungen neigen. Weitere Anwendungsbereiche der Crutchfield-Klammer sind zerstörende Prozesse im Bereiche der Halswirbelsäule, die eine Dauerzugbehandlung über Monate erfordern und schwere Skoliosen mit Lähmungserscheinungen zur Dauerzugsvorbereitung für die Laminektomie.Wegen der einfachen Technik der Anwendung und der Zuverlässigkeit ist die Crutchfield-Klammer der weit weniger leistungsfähigen Glissonschlingenextension vorzuziehen.Mit 16 Textabbildungen (32 Einzelbilder).