Transient inhibition of motor function induced by the Cavitron ultrasonic surgical aspirator during brain mapping.
OBJECTIVE
We report, for the first time, the occurrence of interference between a Cavitron ultrasonic surgical aspirator (CUSA) and intraoperative brain mapping performed by direct electrical stimulation (DES).


METHODS
Intraoperative polygraphic recordings (electrocorticogram and electromyogram) were gathered from a 44-year-old patient harboring a recurrent Grade II oligoastrocytoma operated on with the aid of a CUSA and DES.


RESULTS
Simultaneous use of CUSA and DES at the subcortical level in proximity to the corticospinal tract brought about the abolition of previously evident motor responses. This abolition was fully reversible after the CUSA was turned off. An analogous pattern of motor response inhibition was evident when the DES was applied cortically and the CUSA was used subcortically close to motor pathways. Interestingly, the authors had already observed a similar phenomenon in many patients when the CUSA was used for resection of lesions located within or in proximity to subcortical language pathways. In this setting, the CUSA induced transient speech disturbances that were confirmed afterwards by the DES. This interference with language and motor mapping might be interpreted as a transitory inhibition of axonal conduction.


CONCLUSIONS
The clinical significance of this interference is relevant when the CUSA and DES are used simultaneously for motor mapping because the CUSA can decrease the sensitivity of the brain mapping technique. Further studies will be required to determine the neurophysiological mechanism underlying this interference.
Carrabba
Giorgio
G
Department of Neurosurgery, University of Milan, Fondazione IRCCS Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena, Milan, Italy. giorgio.carrabba@unimi.it
Mandonnet
Emmanuel
E
Fava
Enrica
E
Capelle
Laurent
L
Gaini
Sergio M
SM
Duffau
Hugues
H
Bello
Lorenzo
L
D000328:Adult; D001931:Brain Mapping / Q000295:instrumentation / Q000379:methods; D046690:Deep Brain Stimulation / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods; D019054:Evoked Potentials, Motor / Q000502:physiology*; D005260:Female; D006801:Humans; D016343:Monitoring, Intraoperative / Q000009:adverse effects* / Q000295:instrumentation / Q000379:methods; D014464:Ultrasonic Therapy / Q000009:adverse effects* / Q000379:methods