Efficacy and safety in frameless robot-assisted stereo-electroencephalography (SEEG) for drug-resistant epilepsy.

INTRODUCTION: Stereo-electroencephalography (SEEG) is an invasive procedure, used to identify the epileptogenic zone that can be surgically removed in order to treat drug-resistant epilepsy. Frameless robot-assisted positioning of depth electrodes permits a 3D approach with different obliquities and trajectories. The objective of the present study was to evaluate the morbidity and the accuracy related to this frameless procedure. PATIENTS AND METHODS: Sixty-six patients were managed wherein 901 electrodes were implanted during a 6-year-period. All patients had a postoperative CT-scan that was fused with preoperative MRI planning. In order to assess the accuracy of the procedure, the Euclidian distance was calculated between the coordinates of the planned trajectory and the actual position of the electrode at the entry point and at the target point for 857 electrodes. RESULTS: Among the 66 patients, one (1.5%) experienced a symptomatic brain haematoma and one (1.5%) a stroke-like migraine after radiation therapy (SMART) syndrome. There was no permanent morbidity or mortality. Compared to the classical SEEG approach, a higher rate of asymptomatic postoperative bleeding was found on the CT-scan in 8 patients (12.1%). Any infectious events were recorded. The median accuracy of frameless robotic SEEG procedure was equivalent to a 1.1mm error deviation (0.15-2.48) at the entry point and 2.09mm (1.06-3.72) at the target point respectively, with no differences for double obliquity trajectories. CONCLUSION: Frameless robot-assisted SEEG appears to be a safe procedure, providing sufficient accuracy in order to delineate the epileptogenic zone and represents a helpful tool in the pre-surgical management of refractory epilepsy.

Pure endoscopic management of epileptogenic hypothalamic hamartomas.

Hypothalamic hamartomas (HH) are rare congenital malformations located in the region of the tuber cinereum and third ventricle. Their usual clinical presentation is characterized by gelastic/dacrystic seizures which often become pharmaco-resistant and progress to secondary focal/generalized intractable epilepsy causing mostly in children cognitive and behavioral problems (particularly in cases of progressive epileptic encephalopathy) and precocious puberty. Whereas gelastic seizures can be surgically controlled either by resection of the lesion or disconnection (tissue-destructive) procedures, aimed at functionally prevent the spreading of the epileptic burst; generalized seizures tend to respond better to HH excision rather than isolated neocortical resections, which generally fail to control them. Prospective analysis of 14 consecutive patients harboring HH treated in an 8-year period; 12 patients had unilateral and two bilateral HH. All patients were managed by pure endoscopic excision of the HH. The mean operative time was 48 min and mean hospital stay was 2 days; perioperative blood loss was negligible in all cases. Two patients showed a transient diabetes insipidus (DI); no transient or permanent postoperative neurological deficit or memory impairment was recorded. Complete HH excision was achieved in 10/14 patients. At a mean follow-up of 48 months, no wound infection, meningitis, postoperative hydrocephalus, and/or mortality were recorded in this series of patients. Eight patients became seizure free (Engel class I), 2 other experienced worthwhile improvement of disabling seizures (Engel class II); 2 patients were cured from gelastic attacks while still experiencing focal dyscognitive seizures; and 2, having bilateral HH (both undergoing unilateral HH excision), did not experience significant improvement and required later on a temporal lobectomy coupled to amygdalohyppocampectomy. Overall, the followings resulted to be predictive factors for better outcomes in terms of seizure control: (1) cases of unilateral, Delalande class B, HH, (2) shorter history of epilepsy. Endoscopic resection of HH proved, in our series, to be effective in achieving complete control or in reducing the frequency of seizures. Furthermore, this approach has confirmed its minimally invasive nature with a very low morbidity rate: of note, it allowed to better preserve short-term memory and hypothalamic function.

[Differential Diagnosis of Epileptic and Psychogenic Non-Epileptic Seizures and Treatment Consequences]. / Differenzialdiagnose epileptischer und psychogener nicht-epileptischer Anfälle und sich hieraus ergebende Behandlungskonsequenzen.

Psychogenic non-epileptic seizures (PNES) are one of the most important differential diagnoses of epileptic seizures and represent a challenging pathology for clinicians. The aim of this article is to impart clinical criteria for an accurate diagnosis of psychogenic non-epileptic seizures since an early and appropriate treatment may considerably improve the prognosis.

Evaluation of three risk scores to predict postoperative nausea and vomiting.

BACKGROUND: So far there are three different scores to predict postoperative vomiting (PV: Apfel et al., 1998) or postoperative nausea and vomiting (PONV: Koivuranta et al., 1997; Palazzo and Evans, 1993). All three scores used logistic regression analysis to identify and create weights for the risk factors for PV or PONV. In short, these were sex, age, history of previous PONV, motion sickness, duration of anaesthesia, and use of postoperative opioids. However, an external evaluation and a comparison of these scores has not been performed so far. METHODS: Patients undergoing a variety of surgical procedures under general anaesthesia were studied prospectively. Preoperatively, they completed a questionnaire concerning potential risk factors for the occurrence of PV or PONV implemented in the three risk scores. Balanced anaesthesia (induction agent, nondepolarising neuromuscular blocker, opioid, and inhalation agent in nitrous oxide/oxygen) was performed. No intravenous anaesthesia or any antiemetic prophylaxis was applied. Postoperatively, the patients were observed in the recovery room for the occurrence of PV and PONV and were visited twice on the ward within the 24-h observation period. Both the patients and the nursing staff were asked whether PV or PONV was present. The severity of PONV was categorised using a standardised scoring algorithm. A total of 1,444 patients was finally included into the analysis. Using information of the predicted risk for the individual patients and the actual occurrence of PV or PONV, Receiver Operator Characteristics (ROC-curves) were drawn. The area under each ROC-curve was calculated as a means of the predictive properties of each score and was compared for statistical differences. RESULTS: For prediction of PONV (any severity) the AUC-values (AUC=area under the curve) and the corresponding 95%-confidence intervals were: Apfel: 0.70 (0.67-0.72); Koivuranta: 0.71 (0.69-0.73); Palazzo: 0.68 (0.65-0.70). For prediction of PV: Apfel: 0.73 (0.71-0.75); Koivuranta: 0.73 (0.70-0.75); Palazzo: 0.68 (0.65-0.70). Thus, all three scores appeared to have a moderate accuracy as measured by the AUC. The score of Koivuranta predicts PONV (P=0.007) and also PV (P=0.002) significantly better than Palazzo's score. Furthermore, for predicting of PV the score of Apfel was also superior to Palazzo's score (P=0.005). All three scores predict PV with the same accuracy as PONV. CONCLUSION: The occurrence of PV and PONV in patients undergoing surgery under balanced anaesthesia can be predicted with moderate but acceptable accuracy using one of the available risk scores, regardless of local surgical or anaesthesiological circumstances. For clinical practice, we recommend the score published by Koivuranta, since its calculation is very simple.

[Validation of a risk score for prediction of vomiting in the postoperative period]. / Validierung eines Risikoscores zur Vorhersage von Erbrechen in der postoperativen Phase.

BACKGROUND: A risk score to predict postoperative vomiting was presented in a recent issue of this journal. In the present study this score was evaluated at another hospital under different surgical and anaesthetic conditions. Furthermore, we examined whether the score, which was originally designed to predict the occurrence of postoperative vomiting (POV) only, is also useful for prediction of postoperative nausea and vomiting (PONV). METHODS: The risk score was applied to 226 patients undergoing inpatient orthopaedic surgery under standardised general anaesthesia (propofol, desflurane in N(2)O/O(2), fentanyl, vecuronium, postoperative opioid analgesia). For 24 hours postoperatively, the patients were followed up for the occurrence of nausea, retching, and vomiting. Perioperatively, risk factors for POV were recorded (gender, age, smoking habits, history of previous PONV or motion sickness, duration of anaesthesia). Using these risk factors the individual risk for suffering POV was calculated for each patient. With these data two ROC-curves (for prediction of POV and PONV respectively) were constructed and the area under the ROC-curve (AUC) as a means of the prediction probabilities of the score was calculated. RESULTS: The incidence of POV as predicted by the score (22,8%) fits well to the actual incidence of this event (19,5%). The score predicts the occurrence of POV significantly better than can be expected by a random estimation. In spite of different surgical and anaesthetic conditions, the accuracy of the prediction in the present dataset was not significantly different from that reported by the authors of the scores in their validation set. Furthermore, the prediction properties for POV (AUC: 0,73) were not different from the prediction of PONV (AUC: 0,72). CONCLUSION: The present risk score provides valid prognostic results even under modified surgical and anaesthetic conditions, and, thus, may obviously be applied to other institutions. Furthermore our results support the hypothesis, that individual risk factors rather than the type of surgery or anaesthetic management have a major impact on the occurrence of POV and PONV.