Development of intraoperative electrochemical detection: Wireless instantaneous neurochemical concentration sensor for deep brain stimulation feedback

Department of Neurological Surgery, Mayo Clinic, Rochester, Minnesota 55905, USA.
Neurosurgical FOCUS (Impact Factor: 2.11). 08/2010; 29(2):E6. DOI: 10.3171/2010.5.FOCUS10110
Source: PubMed


Deep brain stimulation (DBS) is effective when there appears to be a distortion in the complex neurochemical circuitry of the brain. Currently, the mechanism of DBS is incompletely understood; however, it has been hypothesized that DBS evokes release of neurochemicals. Well-established chemical detection systems such as microdialysis and mass spectrometry are impractical if one is assessing changes that are happening on a second-to-second time scale or for chronically used implanted recordings, as would be required for DBS feedback. Electrochemical detection techniques such as fast-scan cyclic voltammetry (FSCV) and amperometry have until recently remained in the realm of basic science; however, it is enticing to apply these powerful recording technologies to clinical and translational applications. The Wireless Instantaneous Neurochemical Concentration Sensor (WINCS) currently is a research device designed for human use capable of in vivo FSCV and amperometry, sampling at subsecond time resolution. In this paper, the authors review recent advances in this electrochemical application to DBS technologies. The WINCS can detect dopamine, adenosine, and serotonin by FSCV. For example, FSCV is capable of detecting dopamine in the caudate evoked by stimulation of the subthalamic nucleus/substantia nigra in pig and rat models of DBS. It is further capable of detecting dopamine by amperometry and, when used with enzyme linked sensors, both glutamate and adenosine. In conclusion, WINCS is a highly versatile instrument that allows near real-time (millisecond) detection of neurochemicals important to DBS research. In the future, the neurochemical changes detected using WINCS may be important as surrogate markers for proper DBS placement as well as the sensor component for a "smart" DBS system with electrochemical feedback that allows automatic modulation of stimulation parameters. Current work is under way to establish WINCS use in humans.

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    • "of extra - cellular neuronal activity ( Smith and Grace , 1992 ; Benazzouz et al . , 2000 ; Hashimoto et al . , 2003 ; Maurice et al . , 2003 ; Johnson et al . , 2005 ; Kita et al . , 2005 ; Miocinovic et al . , 2006 ) recent advances in electrode technology allow in vivo mon - itoring of synaptic neurotransmitter activity ( Roham et al . , 2007 ; van Gompel et al . , 2010 ) ."
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    • "As a matter of fact, the Wireless Instantaneous Neurochemical Concentration Sensor (WINCS) is currently a research device, whose resolution was established on pig brain, but it is designed for human use and is capable of in vivo FSCV plus amperometry, sampling at sub-second time resolution (Agnesi et al., 2009; Van Gompel et al., 2010). It promises, for instance, to assess if and to what extent effective STN-DBS is actually changing the tonic/phasic release of endogenous dopamine in human caudate/putamen (Covey and Garris, 2009; Van Gompel et al., 2010). "
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