We demonstrated that DBS plus unilateral ventralis oralis thalamotomy for CP patients with fixed states in the upper extremities is useful not only to treat secondary dystonic movement but also to improve quality of life. In group II patients with post-traumatic dystonia and tardive dyskinesia, we achieved excellent clinical outcomes using a stereotactic procedure.
Background
Deep brain stimulation (DBS) of the centromedian-parafascicular (CM-Pf) thalamic nuclei has been considered an option for treating Tourette syndrome (TS). Using a large animal DBS model, this study was designed to explore the network effects of CM-Pf DBS.
Methods
The combination of DBS and functional MRI (fMRI) is a powerful means of tracing brain circuitry and testing the modulatory effects of electrical stimulation on a neuronal network in vivo. Using a with-in subjects design, we tested the proportional effects of CM and Pf DBS by manipulating current spread and varying stimulation contacts in healthy pigs (n=5).
Results
Our results suggests that CM-Pf DBS has an inhibitory modulating effect in areas that have been suggested as contributing to impaired sensory-motor and emotional processing. The results also help to define the differential neural circuitry effects of the CM and Pf with evidence of prominent sensorimotor/associative effects for CM DBS and prominent limbic/associative effects for Pf DBS.
Conclusions
Our results support the notion that stimulation of deep brain structures, such as the CM-Pf, modulates multiple networks with cortical effects. The networks affected by CM-Pf stimulation in this study reinforce the conceptualization of TS as a condition with psychiatric and motor symptoms and of CM-Pf DBS as a potentially effective tool for treating both types of symptoms.
Introduction
Deep brain stimulation (DBS) is a circuit-based treatment shown to relieve symptoms from multiple neurologic and neuropsychiatric disorders. In order to treat the memory deficit associated with Alzheimer's disease (AD), several clinical trials have tested the efficacy of DBS near the fornix. Early results from these studies indicated that patients who received fornix DBS experienced an improvement in memory and quality of life, yet the mechanisms behind this effect remain controversial. It is known that transmission between the medial limbic and corticolimbic circuits plays an integral role in declarative memory, and dysfunction at the circuit level results in various forms of dementia, including AD. Here, we aimed to determine the potential underlying mechanism of fornix DBS by examining the functional circuitry and brain structures engaged by fornix DBS.
Methods
A multimodal approach was employed to examine global and local temporal changes that occur in an anesthetized swine model of fornix DBS. Changes in global functional activity were measured by functional MRI (fMRI), and local neurochemical changes were monitored by fast scan cyclic voltammetry (FSCV) during electrical stimulation of the fornix. Additionally, intracranial microinfusions into the nucleus accumbens (NAc) were performed to investigate the global activity changes that occur with dopamine and glutamate receptor-specific antagonism.
Results
Hemodynamic responses in both medial limbic and corticolimbic circuits measured by fMRI were induced by fornix DBS. Additionally, fornix DBS resulted in increases in dopamine oxidation current (corresponding to dopamine efflux) monitored by FSCV in the NAc. Finally, fornix DBS-evoked hemodynamic responses in the amygdala and hippocampus decreased following dopamine and glutamate receptor antagonism in the NAc.
Conclusions
The present findings suggest that fornix DBS modulates dopamine release on presynaptic dopaminergic terminals in the NAc, involving excitatory glutamatergic input, and that the medial limbic and corticolimbic circuits interact in a functional loop.
Background: The purpose of this study was to introduce a combination procedure with double C-shaped skin incision and an adjusted dual-floor burr hole to prevent skin complications on the scalp with deep brain stimulation (DBS) surgery. Methods: Between March 2000 and March 2010, 504 DBS electrodes were implanted in 268 patients. We included both bilateral and unilateral DBS surgery cases for Parkinson’s disease, tremor, pain, obsessive-compulsive disorder and intractable seizure accompanied with cranial and IPG insertion procedure, but excluded motor cortex stimulation, and spinal cord stimulation. We used a straight skin incision in 118 patients, double C-shaped skin incision only in 113 patients since March 2006, and combined a double C-shaped skin incision and dual-floor burr hole in 37 patients since August 2009. We compared scalp wound complications and the height subscale of the Vancouver Scar Scale between previous straight or C-shaped skin incision and the combination procedure. Results: We had eight scalp erosions associated with infection (3.0%) and six disconnection (2.2%) cases among 268 patients. Before the use of the double C- skin incision or adjusted dual-floor burr hole technique, we had 5 (4.2%) scalp erosion cases among 118 patients. With the introduction of the C-shaped incision, only 3 patients (2.7%) developed scalp erosion. However, no patient among 37 patients developed scalp erosion after using both double C-shaped skin incision and dual-floor burr hole technique. Scalp bump measured by the height subscale of the Vancouver Scar Scale was more cosmetic in the combination procedure. Conclusion: The combination procedure prevents skin complications associated with DBS surgery, with tensile strength, less impaired vascular supply and better cosmetic outcome. This promising approach prevents unwanted skin complications associated with DBS surgery and improves patient satisfaction.
Although MER can facilitate accurate positioning of electrodes, multi-track MER may increase the risk of intracranial hemorrhage. The accuracy of electrode positioning appears to be acceptable under single track MER during STN DBS with careful electrophysiological and neurological monitoring. The risk of intracranial hemorrhage appears to be minimal, especially in elderly patients with atrophic brains.
Severe deviations and color changes of the facial nerves may be the risk factors for poor surgical outcomes. Future studies with larger sample sizes and investigations of the pathophysiology underlying these findings are needed.
Globus pallidus internus deep brain stimulation can be used to modulate and ameliorate secondary hemidystonia associated with focal post-traumatic brain injury.
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