Deep brain stimulation (DBS) has emerged as a potential intervention for treatment-resistant tardive dyskinesia (TD). Despite promising case reports, no consensus exists regarding optimal stimulation parameters, neuroanatomical target for DBS in TD, or mechanisms underlying its anti-dyskinetic effects. We used vacuous chewing movements (VCMs) in rats treated chronically with haloperidol (HAL) as a TD model to address some of these issues. We show that acute DBS applied to the subthalamic nucleus (STN) or the entopeduncular nucleus (EPN) suppresses VCMs without affecting locomotor activity. Using immediate early gene mapping with zif268 as an index of neuronal activity, we found that STN-DBS induced decreases in activity throughout the basal ganglia, whereas EPN-DBS increased activity in projection regions. While chemical inactivation of the STN or EPN with the GABAA agonist muscimol also suppressed VCMs, muscimol infusion did not mimic the changes in neuronal activity induced by DBS, suggesting that DBS is not equivalent to functional inactivation. We next examined the contribution of serotonin (5-HT) and dopamine (DA) to the anti-dyskinetic effects of DBS. Decreasing 5-HT transmission pharmacologically or with serotonergic lesions decreased VCMs. Using microdialysis and zif268 mapping, we determined that STN- but not EPN-DBS decreased 5-HT release and activity of raphe neurons. However, when the decrease in 5-HT induced by STN-DBS was prevented by pre-treating rats with fluoxetine or fenfluramine, we found that decreasing 5-HT is not necessary for the anti-dyskinetic effects of DBS. STN-DBS transiently increased striatal DA release in intact rats only, whereas EPN-DBS had no effect on DA release. Moreover, pharmacologically elevating DA levels did not suppress VCMs. Together these findings lead us to conclude that increased DA release does not contribute to the anti-dyskinetic effects of DBS. Finally, we compared depressive- and anxiety-like behaviours induced by chronic DBS of the EPN and STN, since adverse psychiatric effects of DBS have become a significant clinical concern. STN-DBS but not EPN-DBS induced depressive-like behaviour in a learned helplessness task. We established that the chronic HAL VCM model preparation may be used to explore mechanisms underlying anti-dyskinetic and psychiatric effects of DBS, and provided the first investigations into these mechanisms.

Deep brain stimulation (DBS) has emerged as a potential intervention for treatment-resistant tardive dyskinesia (TD). Despite promising case reports, no consensus exists regarding optimal stimulation parameters, neuroanatomical target for DBS in TD, or mechanisms underlying its anti-dyskinetic effects. We used vacuous chewing movements (VCMs) in rats treated chronically with haloperidol (HAL) as a TD model to address some of these issues. We show that acute DBS applied to the subthalamic nucleus (STN) or the entopeduncular nucleus (EPN) suppresses VCMs without affecting locomotor activity. Using immediate early gene mapping with zif268 as an index of neuronal activity, we found that STN-DBS induced decreases in activity throughout the basal ganglia, whereas EPN-DBS increased activity in projection regions. While chemical inactivation of the STN or EPN with the GABAA agonist muscimol also suppressed VCMs, muscimol infusion did not mimic the changes in neuronal activity induced by DBS, suggesting that DBS is not equivalent to functional inactivation. We next examined the contribution of serotonin (5-HT) and dopamine (DA) to the anti-dyskinetic effects of DBS. Decreasing 5-HT transmission pharmacologically or with serotonergic lesions decreased VCMs. Using microdialysis and zif268 mapping, we determined that STN- but not EPN-DBS decreased 5-HT release and activity of raphe neurons. However, when the decrease in 5-HT induced by STN-DBS was prevented by pre-treating rats with fluoxetine or fenfluramine, we found that decreasing 5-HT is not necessary for the anti-dyskinetic effects of DBS. STN-DBS transiently increased striatal DA release in intact rats only, whereas EPN-DBS had no effect on DA release. Moreover, pharmacologically elevating DA levels did not suppress VCMs. Together these findings lead us to conclude that increased DA release does not contribute to the anti-dyskinetic effects of DBS. Finally, we compared depressive- and anxiety-like behaviours induced by chronic DBS of the EPN and STN, since adverse psychiatric effects of DBS have become a significant clinical concern. STN-DBS but not EPN-DBS induced depressive-like behaviour in a learned helplessness task. We established that the chronic HAL VCM model preparation may be used to explore mechanisms underlying anti-dyskinetic and psychiatric effects of DBS, and provided the first investigations into these mechanisms.

The in-vivo observation of the neural activities generated by a large number of closely located neurons is believed to be crucial for understanding the nervous system. Moreover, the functional electrical stimulation of the central nervous system is an effective method to restore physiological functions such as limb control, sound sensation, and light perception. The Deep Brain Stimulation (DBS) is being successfully used in the treatment of tremor and rigidity associated with advanced Parkinson's disease. Cochlear implants have also been employed as an effective treatment for sensorineural deafness by means of delivering the electrical stimulation directly to the auditory nerve. The most significant contribution of this PhD study is the development of next-generation microprobes for the simultaneous stimulation and recording of the cortex and deep brain structures. For intracortical applications, millimetre length multisite microprobes that are rigid enough to penetrate into the cortex while integrated with flexible interconnection cables are demanded. In chronic applications, the flexibility of the cable minimizes the tissue damage caused by the relative micro-motion between the brain and the microprobe. Although hybrid approaches have been reported to construct such neural microprobes, these devices are brittle and may impose severe complications if they break inside the tissue. In this project, MEMS fabrication processes were employed to produce non-breakable intracortical microprobes with an improved structural design. These 32 channel devices are integrated with flexible interconnection cables and provide enough mechanical strength for penetration into the tissue. Polyimide-based flexible implants were successfully fabricated and locally reinforced at the tip with embedded 15 µm-thick gold micro-needles. In DBS applications, centimetre long microprobes capable of stimulating and recording the neural activity are required. The currently available DBS probes, manufactured by Medtronic, provide only four cylindrical shaped electrode sites, each 1.5 mm in height and 1.27 mm in diameter. Although suitable for the stimulation of a large brain volume, to measure the activity of a single neuron but to avoid measuring the average response of adjacent cells, recording sites with dimensions in the range of 10 - 20 µm are required. In this work, novel Three Dimensional (3D) multi channel microprobes were fabricated offering 32 independent stimulation and recording electrodes around the shaft of the implant. These microprobes can control the spatial distribution of the charge injected into the tissue to enhance the efficacy and minimize the adverse effects of the DBS treatment. Furthermore, the device volume has been reduced to one third the volume of a conventional Medtronic DBS lead to significantly decrease the tissue damage induced by implantation of the microprobe. For both DBS and intracortical microprobes, the impedance characteristics of the electrodes were studied in acidic and saline solutions. To reduce the channel impedance and enhance the signal to noise ratio, iridium (Ir) was electroplated on gold electrode sites. Stable electrical characteristics were demonstrated for the Ir and gold electrodes over the course of a prolonged pulse stress test for 100 million cycles. The functionality and application potential of the fabricated microprobes were confirmed by the in-vitro measurements of the neural activity in the mouse hippocampus. In order to reduce the number of channels and simplify the signal processing circuitry, multiport electrostatic-actuated switch matrices were successfully developed, fabricated, and characterized for possible integration with neural microprobes to construct a site selection matrix. Magnetic-actuated switches have been also investigated to improve the operation reliability of the MEMS switching devices.

Diss. (sammanfattning) Umeå : Univ., 2007. / Härtill 6 uppsatser.

Atualmente se tem bem estabelecido o tratamento para Doença de Parkinson, dentre eles o DBS (Deep Brain Stimulation). Embora haja controvérsias, muitos estudos têm demonstrado os efeitos adversos do DBS sobre a cognição, humor e comportamento. Assim, este estudo buscou investigar a associação entre os prejuízos cognitivos no pós-operatório e a volumetria cerebral em pacientes parkinsonianos submetidos a DBS, verificando se a correlação entre ambos pode ser considerada fator de risco para os prejuízos encontrados no pós-operatório. Fizeram parte da população estudada 25 indivíduos, 80% do sexo masculino, que foram submetidos ao procedimento cirúrgico de estimulação cerebral profunda (DBS) no Hospital de Clínicas de Porto Alegre (HCPA), em Porto Alegre entre 2012 e 2015. Estes sujeitos foram submetidos a uma bateria de testes cognitivos, bem como a testes clínicos e a ressonância magnética computadorizada nos períodos pré e pós-operatório em 6 meses. Os dados foram analisados através de estatísticas descritivas, coeficiente de correlação de Pearson e Teste t. Os resultados serão considerados significativos a um nível de significância máximo de 5% (p≤ 0,05) e o software estatístico utilizado para a análise será o SPSS versão 20.0. Quanto aos aspectos cognitivos avaliados, somente a fluência verbal fonêmica mostrou redução significativa entre os períodos pré e pós-operatório (p=0,003). A transfixação dos ventrículos foi associada à perda na fluência verbal semântica (p=0,009) e na memória (p=0,016) no pós-operatório. A presença de lesão na substância branca foi associada ao maior prejuízo na função executiva (p=0,017), fluência verbal semântica (p=0,039) e memória (p=0,050). Conclusão: Os prejuízos na fluência verbal semântica e memória no pós-operatório foram associados à presença de lesão na substância branca e a transfixação dos ventrículos pelo cabo com 6 eletrodos. A perda na função executiva foi associada a presença de lesão na substância branca. Os danos na fluência verbal fonêmica no pós-operatório, embora difiram estatisticamente, não foram associados a quaisquer achados da RM. / Currently, the treatment for Parkinson's Disease has been well established, among them DBS (Deep Brain Stimulation). Although controversial, many studies have demonstrated the adverse effects of DBS on cognition, mood, and behavior. Thus, this study sought to investigate the association between cognitive impairment in the postoperative period and cerebral volume in patients with Parkinson's disease who underwent DBS, and whether the correlation between the two can be considered as a risk factor for the possible postoperative losses. Twenty-five subjects, 80% male, who underwent deep brain stimulation (DBS) at the Hospital de Clínicas in Porto Alegre, Porto Alegre, between 2012 and 2015, were submitted to a cognitive battery, as well as clinical trials and computerized magnetic resonance imaging in the preoperative and postoperative periods at 6 months. Data were analyzed through descriptive statistics, Pearson's correlation coefficient and t-test. The results will be considered significant at a maximum significance level of 5% (p≤0.05) and the statistical software used for analysis will be SPSS version 20.0. Concerning the cognitive aspects evaluated, only phonemic verbal fluency showed a significant reduction between the pre and postoperative periods (p = 0.003). The transfixation of the ventricles was associated with loss of semantic verbal fluency (p = 0.009) and memory (p = 0.016) in the postoperative period. The presence of lesion in the white matter was associated with greater impairment in executive function (p = 0.017), semantic verbal fluency (p = 0.039) and memory (p = 0.050). Conclusion: The losses in the semantic verbal fluency and memory in the postoperative period were associated with the presence of white matter lesion and the transfixation of the ventricles by the cable with electrodes. The loss of executive function was associated with the presence of injury in the white matter. Damage to phonemic verbal fluency in 8 the postoperative period, although statistically different, was not associated with any MRI findings.

Atualmente se tem bem estabelecido o tratamento para Doença de Parkinson, dentre eles o DBS (Deep Brain Stimulation). Embora haja controvérsias, muitos estudos têm demonstrado os efeitos adversos do DBS sobre a cognição, humor e comportamento. Assim, este estudo buscou investigar a associação entre os prejuízos cognitivos no pós-operatório e a volumetria cerebral em pacientes parkinsonianos submetidos a DBS, verificando se a correlação entre ambos pode ser considerada fator de risco para os prejuízos encontrados no pós-operatório. Fizeram parte da população estudada 25 indivíduos, 80% do sexo masculino, que foram submetidos ao procedimento cirúrgico de estimulação cerebral profunda (DBS) no Hospital de Clínicas de Porto Alegre (HCPA), em Porto Alegre entre 2012 e 2015. Estes sujeitos foram submetidos a uma bateria de testes cognitivos, bem como a testes clínicos e a ressonância magnética computadorizada nos períodos pré e pós-operatório em 6 meses. Os dados foram analisados através de estatísticas descritivas, coeficiente de correlação de Pearson e Teste t. Os resultados serão considerados significativos a um nível de significância máximo de 5% (p≤ 0,05) e o software estatístico utilizado para a análise será o SPSS versão 20.0. Quanto aos aspectos cognitivos avaliados, somente a fluência verbal fonêmica mostrou redução significativa entre os períodos pré e pós-operatório (p=0,003). A transfixação dos ventrículos foi associada à perda na fluência verbal semântica (p=0,009) e na memória (p=0,016) no pós-operatório. A presença de lesão na substância branca foi associada ao maior prejuízo na função executiva (p=0,017), fluência verbal semântica (p=0,039) e memória (p=0,050). Conclusão: Os prejuízos na fluência verbal semântica e memória no pós-operatório foram associados à presença de lesão na substância branca e a transfixação dos ventrículos pelo cabo com 6 eletrodos. A perda na função executiva foi associada a presença de lesão na substância branca. Os danos na fluência verbal fonêmica no pós-operatório, embora difiram estatisticamente, não foram associados a quaisquer achados da RM. / Currently, the treatment for Parkinson's Disease has been well established, among them DBS (Deep Brain Stimulation). Although controversial, many studies have demonstrated the adverse effects of DBS on cognition, mood, and behavior. Thus, this study sought to investigate the association between cognitive impairment in the postoperative period and cerebral volume in patients with Parkinson's disease who underwent DBS, and whether the correlation between the two can be considered as a risk factor for the possible postoperative losses. Twenty-five subjects, 80% male, who underwent deep brain stimulation (DBS) at the Hospital de Clínicas in Porto Alegre, Porto Alegre, between 2012 and 2015, were submitted to a cognitive battery, as well as clinical trials and computerized magnetic resonance imaging in the preoperative and postoperative periods at 6 months. Data were analyzed through descriptive statistics, Pearson's correlation coefficient and t-test. The results will be considered significant at a maximum significance level of 5% (p≤0.05) and the statistical software used for analysis will be SPSS version 20.0. Concerning the cognitive aspects evaluated, only phonemic verbal fluency showed a significant reduction between the pre and postoperative periods (p = 0.003). The transfixation of the ventricles was associated with loss of semantic verbal fluency (p = 0.009) and memory (p = 0.016) in the postoperative period. The presence of lesion in the white matter was associated with greater impairment in executive function (p = 0.017), semantic verbal fluency (p = 0.039) and memory (p = 0.050). Conclusion: The losses in the semantic verbal fluency and memory in the postoperative period were associated with the presence of white matter lesion and the transfixation of the ventricles by the cable with electrodes. The loss of executive function was associated with the presence of injury in the white matter. Damage to phonemic verbal fluency in 8 the postoperative period, although statistically different, was not associated with any MRI findings.

abstract: Parkinson's disease is a neurodegenerative condition diagnosed on patients with clinical history and motor signs of tremor, rigidity and bradykinesia, and the estimated number of patients living with Parkinson's disease around the world is seven to ten million. Deep brain stimulation (DBS) provides substantial relief of the motor signs of Parkinson's disease patients. It is an advanced surgical technique that is used when drug therapy is no longer sufficient for Parkinson's disease patients. DBS alleviates the motor symptoms of Parkinson's disease by targeting the subthalamic nucleus using high-frequency electrical stimulation. This work proposes a behavior recognition model for patients with Parkinson's disease. In particular, an adaptive learning method is proposed to classify behavioral tasks of Parkinson's disease patients using local field potential and electrocorticography signals that are collected during DBS implantation surgeries. Unique patterns exhibited between these signals in a matched feature space would lead to distinction between motor and language behavioral tasks. Unique features are first extracted from deep brain signals in the time-frequency space using the matching pursuit decomposition algorithm. The Dirichlet process Gaussian mixture model uses the extracted features to cluster the different behavioral signal patterns, without training or any prior information. The performance of the method is then compared with other machine learning methods and the advantages of each method is discussed under different conditions. / Dissertation/Thesis / Masters Thesis Electrical Engineering 2015

Atualmente se tem bem estabelecido o tratamento para Doença de Parkinson, dentre eles o DBS (Deep Brain Stimulation). Embora haja controvérsias, muitos estudos têm demonstrado os efeitos adversos do DBS sobre a cognição, humor e comportamento. Assim, este estudo buscou investigar a associação entre os prejuízos cognitivos no pós-operatório e a volumetria cerebral em pacientes parkinsonianos submetidos a DBS, verificando se a correlação entre ambos pode ser considerada fator de risco para os prejuízos encontrados no pós-operatório. Fizeram parte da população estudada 25 indivíduos, 80% do sexo masculino, que foram submetidos ao procedimento cirúrgico de estimulação cerebral profunda (DBS) no Hospital de Clínicas de Porto Alegre (HCPA), em Porto Alegre entre 2012 e 2015. Estes sujeitos foram submetidos a uma bateria de testes cognitivos, bem como a testes clínicos e a ressonância magnética computadorizada nos períodos pré e pós-operatório em 6 meses. Os dados foram analisados através de estatísticas descritivas, coeficiente de correlação de Pearson e Teste t. Os resultados serão considerados significativos a um nível de significância máximo de 5% (p≤ 0,05) e o software estatístico utilizado para a análise será o SPSS versão 20.0. Quanto aos aspectos cognitivos avaliados, somente a fluência verbal fonêmica mostrou redução significativa entre os períodos pré e pós-operatório (p=0,003). A transfixação dos ventrículos foi associada à perda na fluência verbal semântica (p=0,009) e na memória (p=0,016) no pós-operatório. A presença de lesão na substância branca foi associada ao maior prejuízo na função executiva (p=0,017), fluência verbal semântica (p=0,039) e memória (p=0,050). Conclusão: Os prejuízos na fluência verbal semântica e memória no pós-operatório foram associados à presença de lesão na substância branca e a transfixação dos ventrículos pelo cabo com 6 eletrodos. A perda na função executiva foi associada a presença de lesão na substância branca. Os danos na fluência verbal fonêmica no pós-operatório, embora difiram estatisticamente, não foram associados a quaisquer achados da RM. / Currently, the treatment for Parkinson's Disease has been well established, among them DBS (Deep Brain Stimulation). Although controversial, many studies have demonstrated the adverse effects of DBS on cognition, mood, and behavior. Thus, this study sought to investigate the association between cognitive impairment in the postoperative period and cerebral volume in patients with Parkinson's disease who underwent DBS, and whether the correlation between the two can be considered as a risk factor for the possible postoperative losses. Twenty-five subjects, 80% male, who underwent deep brain stimulation (DBS) at the Hospital de Clínicas in Porto Alegre, Porto Alegre, between 2012 and 2015, were submitted to a cognitive battery, as well as clinical trials and computerized magnetic resonance imaging in the preoperative and postoperative periods at 6 months. Data were analyzed through descriptive statistics, Pearson's correlation coefficient and t-test. The results will be considered significant at a maximum significance level of 5% (p≤0.05) and the statistical software used for analysis will be SPSS version 20.0. Concerning the cognitive aspects evaluated, only phonemic verbal fluency showed a significant reduction between the pre and postoperative periods (p = 0.003). The transfixation of the ventricles was associated with loss of semantic verbal fluency (p = 0.009) and memory (p = 0.016) in the postoperative period. The presence of lesion in the white matter was associated with greater impairment in executive function (p = 0.017), semantic verbal fluency (p = 0.039) and memory (p = 0.050). Conclusion: The losses in the semantic verbal fluency and memory in the postoperative period were associated with the presence of white matter lesion and the transfixation of the ventricles by the cable with electrodes. The loss of executive function was associated with the presence of injury in the white matter. Damage to phonemic verbal fluency in 8 the postoperative period, although statistically different, was not associated with any MRI findings.

Atualmente se tem bem estabelecido o tratamento para Doença de Parkinson, dentre eles o DBS (Deep Brain Stimulation). Embora haja controvérsias, muitos estudos têm demonstrado os efeitos adversos do DBS sobre a cognição, humor e comportamento. Assim, este estudo buscou investigar a associação entre os prejuízos cognitivos no pós-operatório e a volumetria cerebral em pacientes parkinsonianos submetidos a DBS, verificando se a correlação entre ambos pode ser considerada fator de risco para os prejuízos encontrados no pós-operatório. Fizeram parte da população estudada 25 indivíduos, 80% do sexo masculino, que foram submetidos ao procedimento cirúrgico de estimulação cerebral profunda (DBS) no Hospital de Clínicas de Porto Alegre (HCPA), em Porto Alegre entre 2012 e 2015. Estes sujeitos foram submetidos a uma bateria de testes cognitivos, bem como a testes clínicos e a ressonância magnética computadorizada nos períodos pré e pós-operatório em 6 meses. Os dados foram analisados através de estatísticas descritivas, coeficiente de correlação de Pearson e Teste t. Os resultados serão considerados significativos a um nível de significância máximo de 5% (p≤ 0,05) e o software estatístico utilizado para a análise será o SPSS versão 20.0. Quanto aos aspectos cognitivos avaliados, somente a fluência verbal fonêmica mostrou redução significativa entre os períodos pré e pós-operatório (p=0,003). A transfixação dos ventrículos foi associada à perda na fluência verbal semântica (p=0,009) e na memória (p=0,016) no pós-operatório. A presença de lesão na substância branca foi associada ao maior prejuízo na função executiva (p=0,017), fluência verbal semântica (p=0,039) e memória (p=0,050). Conclusão: Os prejuízos na fluência verbal semântica e memória no pós-operatório foram associados à presença de lesão na substância branca e a transfixação dos ventrículos pelo cabo com 6 eletrodos. A perda na função executiva foi associada a presença de lesão na substância branca. Os danos na fluência verbal fonêmica no pós-operatório, embora difiram estatisticamente, não foram associados a quaisquer achados da RM. / Currently, the treatment for Parkinson's Disease has been well established, among them DBS (Deep Brain Stimulation). Although controversial, many studies have demonstrated the adverse effects of DBS on cognition, mood, and behavior. Thus, this study sought to investigate the association between cognitive impairment in the postoperative period and cerebral volume in patients with Parkinson's disease who underwent DBS, and whether the correlation between the two can be considered as a risk factor for the possible postoperative losses. Twenty-five subjects, 80% male, who underwent deep brain stimulation (DBS) at the Hospital de Clínicas in Porto Alegre, Porto Alegre, between 2012 and 2015, were submitted to a cognitive battery, as well as clinical trials and computerized magnetic resonance imaging in the preoperative and postoperative periods at 6 months. Data were analyzed through descriptive statistics, Pearson's correlation coefficient and t-test. The results will be considered significant at a maximum significance level of 5% (p≤0.05) and the statistical software used for analysis will be SPSS version 20.0. Concerning the cognitive aspects evaluated, only phonemic verbal fluency showed a significant reduction between the pre and postoperative periods (p = 0.003). The transfixation of the ventricles was associated with loss of semantic verbal fluency (p = 0.009) and memory (p = 0.016) in the postoperative period. The presence of lesion in the white matter was associated with greater impairment in executive function (p = 0.017), semantic verbal fluency (p = 0.039) and memory (p = 0.050). Conclusion: The losses in the semantic verbal fluency and memory in the postoperative period were associated with the presence of white matter lesion and the transfixation of the ventricles by the cable with electrodes. The loss of executive function was associated with the presence of injury in the white matter. Damage to phonemic verbal fluency in 8 the postoperative period, although statistically different, was not associated with any MRI findings.

abstract: The efficacy of deep brain stimulation (DBS) in Parkinson's disease (PD) has been convincingly demonstrated in studies that compare motor performance with and without stimulation, but characterization of performance at intermediate stimulation amplitudes has been limited. This study investigated the effects of changing DBS amplitude in order to assess dose-response characteristics, inter-subject variability, consistency of effect across outcome measures, and day-to-day variability. Eight subjects with PD and bilateral DBS systems were evaluated at their clinically determined stimulation (CDS) and at three reduced amplitude conditions: approximately 70%, 30%, and 0% of the CDS (MOD, LOW, and OFF, respectively). Overall symptom severity and performance on a battery of motor tasks - gait, postural control, single-joint flexion-extension, postural tremor, and tapping - were assessed at each condition using the motor section of the Unified Parkinson's Disease Rating Scale (UPDRS-III) and quantitative measures. Data were analyzed to determine whether subjects demonstrated a threshold response (one decrement in stimulation resulted in ≥ 70% of the maximum change) or a graded response to reduced stimulation. Day-to-day variability was assessed using the CDS data from the three testing sessions. Although the cohort as a whole demonstrated a graded response on several measures, there was high variability across subjects, with subsets exhibiting graded, threshold, or minimal responses. Some subjects experienced greater variability in their CDS performance across the three days than the change induced by reducing stimulation. For several tasks, a subset of subjects exhibited improved performance at one or more of the reduced conditions. Reducing stimulation did not affect all subjects equally, nor did it uniformly affect each subject's performance across tasks. These results indicate that altered recruitment of neural structures can differentially affect motor capabilities and demonstrate the need for clinical consideration of the effects on multiple symptoms across several days when selecting DBS parameters. / Dissertation/Thesis / Ph.D. Bioengineering 2013