During deep brain stimulation surgery for Parkinson’s disease, the patient is usually awake so doctors can test whether the electrode is placed correctly. Not necessary, according to the thesis of neurosurgeon Saman Vinke of Radboud university medical center. An MRI scan makes measurements and tests during the operation superfluous. As a result, the operation can be performed under anesthesia and it is possible to perform two operations per day instead of one. The anesthesia mainly convinces women with Parkinson’s, who opt less often for an operation in an awake state.
Trembling, slowness and stiffness are annoying symptoms of Parkinson’s disease. Small electrical impulses in the brain, so-called deep brain stimulation (DBS), can help. To do this, a neurosurgeon places two electrodes in a deep part of the brain through holes in the skull. Via a pacemaker, the electrodes give electrical impulses, which can greatly reduce the complaints. In the Netherlands, this involves three hundred procedures per year.
Coffee bean
In the classic surgical method, the patient is largely awake. ‘This method is thirty years old,’ says neurosurgeon Saman Vinke. ‘The surgeon uses small currents to find the right place for the electrodes. Thanks to the awake state, the surgeon can immediately check whether the symptoms are improving.’ But there are drawbacks to this classical method. For example, the operation takes almost an entire working day, most of which the patient is awake with the head fixed. In addition, the patient has to temporarily stop taking medication, which makes the complaints worse.
Vinke investigated whether the measurements and tests during the operation, for which a patient must be awake and without medication, contribute to determining the best position for the DBS electrode. ‘Such an electrode has the size of a spaghetti strand. We place these in a nucleus in the brain the size of a coffee bean, the so-called subthalamic nucleus,’ explains Vinke. ‘We use a custom-made MRI scan that enables us to properly detect the coffee bean. Our study shows that the measurements and tests do not contribute to determining the correct place to place the spaghetti string when we use this MRI.’
More women
Thanks to the MRI scan, doctors can perform the operation under anesthesia, which offers great advantages. Vinke: ‘The procedure is much shorter. We can now operate on two patients in one day instead of one. In addition, patients continue to take their medicines as usual, so that the symptoms remain stable before the operation.’
Another striking advantage that Vinke describes in his dissertation is that women in particular opt much more often for DBS surgery if it can be performed under anesthesia. ‘Parkinson’s occurs in 40 percent of cases in women. But in our study, only seventeen percent of the patients with the classical surgical method were women’, explains Vinke. ‘Since we started operating under anesthesia, that percentage has risen to over forty percent, as the disease is also distributed in the population.’ Vinke could not find out why women opt less for an awake operation. This will be further investigated in follow-up research.
Tip of the iceberg
Radboudumc now only performs DBS operations for Parkinson’s disease under MRI guidance and under anesthesia. Worldwide, in the vast majority of situations, the procedure is still performed according to the traditional awake or partially awake method. Surgeons from abroad regularly come to see how the new method works. Vinke: ‘I think we could perform this operation much more often. However, the procedure is not suitable for everyone and also has side effects, so we have to take that into account, but we are only treating the tip of the iceberg.’
Learn more about this promotion
Promotion on January 20, 2023 at 12:30 pm by Saman Vinke. Dissertation title: Paradigm shifts in the surgical treatment of Parkinson’s disease (available online after 20 January). Supervisor: Prof. Dr. RHMA Bartels. Co-promoters: Dr. RAJ Esselink and Dr. PL Kubben (Maastricht UMC+). The defense can be followed via this live stream.