Artikel
Traintime as a quantitative EMG parameter for facial nerve function during surgery in the cerebellopontine angle
Trainzeit als quantitativer EMG-Parameter zur Beurteilung der Fazialisfunktion in der Kleinhirnbrückenwinkelchirurgie
Suche in Medline nach
Autoren
Veröffentlicht: | 4. Mai 2005 |
---|
Gliederung
Text
Objective
The authors describe a quantitative warning parameter for intraoperative monitoring of the facial nerve during surgery of acoustic neuroma. This parameter, which was called “traintime”, was assessed automatically by a dedicated software program. It was correlated with postoperative clinical outcome in order to demonstrate its clinical significance.
Methods
40 patients who underwent surgery on acoustic neuroma were examined. During the entire operative procedure free-running EMG-signals were recorded from muscles targeted by the facial nerve. A software program, specifically designed for this purpose, analyzed these continuous recordings off-line. The program was developed to detect A-trains, a specific pattern of EMG-activity, which is known to be associated with postoperative facial nerve paresis. The parameter traintime was assessed in summing up the intervals of time during which A-trains occurred.
Results
A strong correlation between the length of traintime measured in seconds and deterioration of postoperative facial nerve function was demonstrated. Certain, consecutive thresholds were defined. Their transgression reliably indicated postoperative paresis of the facial nerve and its extent. Differences between the impact of traintime on patients with, respectively without preoperative paresis were observed.
Conclusions
Traintime as a quantitative warning parameter was shown to be a reliable indicator of facial nerve paresis in surgery for acoustic neuromas. Online assessment in the operating room can improve the quality of surgery by keeping the surgeon constantly informed about the condition of the facial nerve, thus enabling him to adapt the operative strategy to the facial nerve’s functional integrity.