Title: Wireless Fast-Scan Cyclic Voltammetry to Monitor Adenosine in Patients With Essential Tremor During Deep Brain Stimulation
Journal: Mayo Clinic Proceedings 87(8):760-5
Link: https://doi.org/10.1016/j.mayocp.2012.05.006
Comments:
Essential tremor (ET) is a progressive neurological disorder and the most common type of movement disorder, which causes involuntary rhythmic contraction and relaxation of certain muscle groups. As one of the effective neurosurgical treatments for essential tremor, deep brain stimulation (DBS) treats movement disorders by implanting an electrode deep within the brain. In this paper, the authors investigated how the essential tremor was significantly reduced during deep brain stimulation and suggested that the effect of DBS could attributed to the implantation of the microelectrode per se (also known as microthalamotomy) but not stimulation in the thalamic nucleus.
For the mechanisms of the effect of DBS, there are two possibilities that have been suggested. One is that it has a relationship with microlesioning targeted brain tissue, which is a microscopic version of tissue ablation in thalamotomy. The other one is that implanting the electrode induces immediate neuro-chemical release. To investigate these possibilities, they used fast-scan cyclic voltammetry (FSCV) to detect real-time neurochemical changes in human subjects undergoing DBS implantation surgery. Seven patients were observed in reduced tremor amplitude for the microthalamotomy effect. The results by real-time in vivo FSCV neurochemical recordings in human show that implanting a DBS electrode induces adenosine release concurrent with tremor arrest. It also confirms that changes in neurochemical concentrations may be a contributing factor, and the transient nature of the microcellular effect can be partly explained by the limited duration of neurochemical release and diffusion into surrounding tissues.
Adenosine has been implicated in neurotransmission mediating a variety of functions such as inflammation and pain. The applications of in vivo recording of such neurotransmitters might clarify neurobiological mechanisms of ET and help elucidate the therapeutic effects of DBS for neuromodulation.
