Intraoperative neuromonitoring during acoustic neuroma operations
Intraoperative electrophysiological monitoring comprises the monitoring of important functions of the nervous system during a neurosurgical procedure.
Intraoperative = during the operation
Electrophysiological = electric display of the processes in the nerves
Monitoring = monitoring on the screen
It has two goals: firstly, it can help localise important structures in the operating area during the initial phase of the operation.
Secondly, it will alert the doctor monitoring of any irritation to the cranial nerves, which can happen if the surgeon is dangerously near to a nerve. The surgeon then has the chance to interrupt the work briefly, undo the possible changes that have occurred and at the same time change the operation strategy.
It works under the principle of "stimulation and impulse response". A desired stimulation, to establish the existence and functionability of a nerve and an undesired contact when removing the tumour activates an impulse, which is recorded, signally visually and acoustically.
There a number of procedures that can be combined and applied, according to the situation, with the following goals: monitoring the mimic facial muscles, the jaw muscles, the swallow function and the tongue, the muscular system of the eye muscles and the Auditory Evoked Potential to control the hearing function. For all these the muscle response is registered after electric stimulation due to mechanic stimulation of the nerves. Superficial sensors are painlessly attached, which transfer the incoming stimuli to the equipment.
Mit der Einführung des intraoperativen Monitorings konnten die Raten der Erhaltung des Hörvermögens und der Erhaltung der Funktionsfähigkeit des Gleichgewichtsnerven deutlich gesteigert werden.
With the introduction of intraoperative monitoring the preservation rates hearing ability and functionability of the balance nerves have increased considerably.
Intraoperative = during the operation
Electrophysiological = electric display of the processes in the nerves
Monitoring = monitoring on the screen
It has two goals: firstly, it can help localise important structures in the operating area during the initial phase of the operation.
Secondly, it will alert the doctor monitoring of any irritation to the cranial nerves, which can happen if the surgeon is dangerously near to a nerve. The surgeon then has the chance to interrupt the work briefly, undo the possible changes that have occurred and at the same time change the operation strategy.
It works under the principle of "stimulation and impulse response". A desired stimulation, to establish the existence and functionability of a nerve and an undesired contact when removing the tumour activates an impulse, which is recorded, signally visually and acoustically.
There a number of procedures that can be combined and applied, according to the situation, with the following goals: monitoring the mimic facial muscles, the jaw muscles, the swallow function and the tongue, the muscular system of the eye muscles and the Auditory Evoked Potential to control the hearing function. For all these the muscle response is registered after electric stimulation due to mechanic stimulation of the nerves. Superficial sensors are painlessly attached, which transfer the incoming stimuli to the equipment.
Mit der Einführung des intraoperativen Monitorings konnten die Raten der Erhaltung des Hörvermögens und der Erhaltung der Funktionsfähigkeit des Gleichgewichtsnerven deutlich gesteigert werden.
With the introduction of intraoperative monitoring the preservation rates hearing ability and functionability of the balance nerves have increased considerably.
Sensors for monitoring during acoustic neuroma operations
(Source: Website of University Hospital Würzburg)
Monitoring system «ISIS IOM System»
Explanation of the image (german)
(Source: Website of Fa. inomed Medizintechnik GmbH)
The curves show the function of the auditory nerves before (left) and after (right) the tumour's removal. A functional, useful hearing ability could be preserved.
(Source: Website of University Hospital Greifswald)