Cognitive outcome and reliable change indices two years following bilateral subthalamic nucleus deep brain stimulation

Subthalamic nucleus deep brain stimulation (STN-DBS) is currently the treatment of choice for medication-resistant levodopa-related motor complications in patients with Parkinson's disease (PD). While STN-DBS often results in meaningful motor improvements, consensus regarding long-term neuropsychological outcome continues to be debated. We assessed the cognitive outcomes of 19 STN-DBS patients compared to a group of 18 medically-managed PD patients on a comprehensive neuropsychological battery at baseline and two years post-surgery. Patients did not demonstrate changes in global cognitive functioning on screening measures. However, neuropsychological results revealed impairments in nonverbal recall, oral information processing speed, and lexical and semantic fluency in STN-DBS patients compared to PD controls 2 years post-surgery in these preliminary analyses. Additionally, reliable change indices revealed that approximately 50% of STN-DBS patients demonstrated significant declines in nonverbal memory and oral information processing speed compared to 25-30% of PD controls, and 26% of STN-DBS patients declined on lexical fluency compared to 11% of PD patients. Approximately 30% of both groups declined on semantic fluency. The number of STN-DBS patients who converted to dementia 2 years following surgery was not significantly different from the PD participants (32% versus 16%, respectively). Our results suggest that neuropsychological evaluations may identify possible mild cognitive changes following surgery.     

Beyond verbal fluency: investigating the long-term effects of bilateral subthalamic (STN) deep brain stimulation (DBS) on language function in two cases

Cognitive functioning has been described as largely impervious to chronic STN-DBS administered over 12-month periods. In relation to the domain of language, however, the effects of STN-DBS are yet to be thoroughly delineated. Verbal fluency tasks represent an almost exclusively applied index of linguistic proficiency relative to neuropsychological research within this population. Comprehensive investigations of the impact of STN-DBS on language function, however, have never been undertaken. The more precise elucidation of the role of the STN in the mediation of language processes, by way of assessments which probe language comprehension and production mechanisms, served as the primary focus of this research. Longitudinal analysis also afforded consideration of the way in which cognitive-linguistic circuits respond to STN-DBS over time. Bilateral STN-DBS primarily effected clinically reliable fluctuations (i.e., both improvements and declines) in performance in both subjects on tasks demanding cognitive-linguistic flexibility in the formulation and comprehension of complex language. Of particular note, both subjects demonstrated a cumulative increase in the proportion of reliable post-operative improvements achieved over time. The findings of this research lend support to models of subcortical participation in language which endorse a role for the STN, and suggest that bilateral STN-DBS may serve to enhance the proficiency of basal ganglia-thalamocortical linguistic circuits over time.     

Beyond verbal fluency: Investigating the long-term effects of bilateral subthalamic (STN) deep brain stimulation (DBS) on language function in two cases

Cognitive functioning has been described as largely impervious to chronic STN-DBS administered over 12-month periods. In relation to the domain of language, however, the effects of STN-DBS are yet to be thoroughly delineated. Verbal fluency tasks represent an almost exclusively applied index of linguistic proficiency relative to neuropsychological research within this population. Comprehensive investigations of the impact of STN-DBS on language function, however, have never been undertaken. The more precise elucidation of the role of the STN in the mediation of language processes, by way of assessments which probe language comprehension and production mechanisms, served as the primary focus of this research. Longitudinal analysis also afforded consideration of the way in which cognitive-linguistic circuits respond to STN-DBS over time. Bilateral STN-DBS primarily effected clinically reliable fluctuations (i.e., both improvements and declines) in performance in both subjects on tasks demanding cognitive-linguistic flexibility in the formulation and comprehension of complex language. Of particular note, both subjects demonstrated a cumulative increase in the proportion of reliable post-operative improvements achieved over time. The findings of this research lend support to models of subcortical participation in language which endorse a role for the STN, and suggest that bilateral STN-DBS may serve to enhance the proficiency of basal ganglia-thalamocortical linguistic circuits over time.     

CAC Classics

Background : Thalamotomy has been reported to be successful in ameliorating the motor symptoms of tremor and/or rigidity in people with Parkinson's disease (PD), emphasising the bona fide contribution of this subcortical nucleus to the neural circuitry subserving motor function. Despite evidence of parallel yet segregated associative and motor corticosubcortical-cortical circuits, comparatively few studies have investigated the effects of this procedure on cognitive functions. In particular, research pertaining to the impact of thalamotomy on linguistic processes is fundamentally lacking. Aims : The purpose of this research was to investigate the effects of thalamotomy in the language dominant and non-dominant hemispheres on linguistic functioning, relative to operative theoretical models of subcortical participation in language. This paper compares the linguistic profiles of two males with PD, aged 75 years (10 years of formal education) and 62 years (22 years of formal education), subsequent to unilateral thalamotomy procedures within the language dominant and non-dominant hemispheres, respectively. Methods & Procedures : Comprehensive linguistic profiles comprising general and high-level linguistic abilities in addition to on-line semantic processing skills were compiled up to 1 month prior to surgery and 3 months post-operatively, within perceived "on periods (i.e., when optimally medicated). Pre- and post-operative language performances were compared within-subjects to a group of 16 non-surgical Parkinson's controls (NSPD) and a group of 16 non-neurologically impaired adults (NC). Outcomes & Results : The findings of this research suggest a laterality effect with regard to the contribution of the thalamus to high-level linguistic abilities and, potentially, the temporal processing of semantic information. This outcome supports the application of highlevel linguistic assessments and measures of semantic processing proficiency to the clinical management of individuals with dominant thalamic lesions. Conclusions : The results reported lend support to contemporary theories of dominant thalamic participation in language, serving to further elucidate our current understanding of the role of subcortical structures in mediating linguistic processes, relevant to cortical hemispheric dominance.     

微电极导向核团毁损术和脑深部电刺激术治疗帕金森病的疗效分析

目的 观察微电极导向核团毁损术和脑深部电刺激术（DBS）治疗帕金森病的临床疗效。方法 对380例接受微电极导向立体定向核团毁损术和25例脑深部电刺激丘脑底核（STN—DBS）治疗的帕金森病患者进行随访和神经功能评估，分别获得术前、术后和DBS开启后1周、6个月、2年及5年的不同服药状态下统一帕金森病量表（UPDRS）评分资料，采用威尔科克森检验（Wilcoxontest），比较不同术后时间点UPDRS运动评分与术前评分的差异。结果 核团毁损术和DBS在术后1周、6个月及2年随访中均能明显改善术前帕金森病患者的UPDRS运动评分，减轻左旋多巴诱发的运动波动及异动症。在5年随访时间点上仅DBS治疗组较术前比较仍显示差异性。而且DBS组患者术后左旋多巴服药的剂量较术前减少。核团毁损组总体并发症的发生率为5．8％，永久性并发症的发生率为1．2％。DBS组未发生严重并发症。结论 核团毁损术和DBS两者被证实是中晚期帕金森病安全、有效的治疗方法，能显著改善术前帕金森病患者的UPDRS运动评分，减轻左旋多巴诱发的运动波动及异动症。STN—DBS较毁损术更具有独特的可控性、安全性和长效性。     

Negative impact of borderline global cognitive scores on quality of life after subthalamic nucleus stimulation in Parkinson's disease

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) significantly improves quality of life (QoL) in Parkinson's disease (PD). Dementia is considered as a contraindication for STN-DBS. However, no controlled study assessed the impact of STN-DBS on the QoL and motor outcome in PD patients with a borderline global cognitive impairment. We studied clinical baseline and progression parameters in a cohort of STN-DBS patients with a global cognitive score still in the non-demented range but scoring in the lowest quartile of the Mattis Dementia Rating Scale (MDRS), a measure of global cognitive functioning. Data from a German randomised controlled study comparing DBS (60 patients) with best medical treatment (BMT, 59 patients) were analysed. Changes in patients' QoL scores were assessed using the Parkinson's disease questionnaire (PDQ-39) at baseline and at the 6 months follow up. Patients were split into four groups according to their MDRS performance at baseline and these groups were compared in the context of motor outcome and QoL. Twelve out of sixty patients of the STN-DBS group scored in the lowest quartile of the MDRS (range between one hundred thirty and one hundred thirty seven points). An individual analysis revealed that 3 of 12 patients showed a clinical relevant improvement in QoL whereas the group statistics did not reveal any significant improvement in QoL measures after STN-DBS compared to the BMT group. Since this failure to improve in QoL cannot be explained by a failure to improve in motor functions, stimulation settings and psychiatric scales after STN-DBS, the failure to improve in QoL in patients with a borderline global cognitive score might be specifically related to lower cognitive functioning.     

Subthalamic stimulation activates internal pallidus: evidence from cGMP microdialysis in PD patients

Parkinson's disease patients benefit from deep brain stimulation (DBS) in subthalamic nucleus (STN), but the basis for this effect is still disputed. In this intraoperative microdialysis study, we found elevated cGMP extracellular concentrations in the internal segment of the globus pallidus, despite negligible changes in glutamate levels, during a clinically effective STN-DBS. This supports the view that a clinically beneficial effect of STN-DBS is paralleled by an augmentation (and not an inactivation) of the STN output onto the GPi.     

Grammar improvement following deep brain stimulation of the subthalamic and the pedunculopontine nuclei in advanced Parkinson's disease: A pilot study

Combined deep brain stimulation of the subthalamic (STN) and pedunculopontine (PPN) nuclei has been recently proposed as surgical treatment of advanced Parkinson's disease. STN stimulation alone has been shown to provide selective improvement of the grammatical aspect of language. We studied five advanced Parkinson's disease patients who underwent combined deep brain stimulation (STN + PPN). Overall cognitive profile did not change. On the contrary, an interesting trend towards reduction of ungrammatical errors (particularly substitution of free and inflectional morphemes) was found when stimulating the STN, and also the PPN, when the STN was switched off. These findings replicate previous observations on the STN, and provide the rationale for further investigation of the role of the PPN in processing linguistic grammar.     

Gender differences in patients with Parkinson's disease treated with subthalamic deep brain stimulation.

We investigated gender-differences in clinical phenomenology and response to deep brain stimulation (DBS) of the subthalamic nucleus (STN) in a group of patients with advanced Parkinson's disease (PD). Thirty-eight consecutive patients with PD (22 men and 16 women), bilaterally implanted for DBS of the STN, were evaluated 1 month before and 11 to 14 months after surgery. Gender differences in severity of the disease (HY and UPDRS), ability in the activities of daily living (ADL, UPDRS II), tremor and rigidity (UPDRS III), bradykinesia (UPDRS III and hand tapping test), levodopa-induced dyskinesias (LIDs, UPDRS IV), and levodopa equivalent daily dosage (LEDD) were analyzed before and after intervention. We found a predominantly male population, with no gender-related differences in age at onset, disease progression rate, or severity of disease. Nevertheless, women had more severe LIDs than men, only before the intervention. Bradykinesia was significantly less responsive to any kind of treatment (pharmacologic and neurosurgical) in women than in men. Finally, although STN-DBS induced similar total benefits in both genders, postoperative assessment suggested that the ADL improved more in women than in men. Women and men with advanced PD appear to differ in some clinical features and in response to dopaminergic and STN-DBS treatment.     

Reappraising contemporary theories of subcortical participation in language: proposing an interhemispheric regulatory function for the subthalamic nucleus (STN) in the mediation of high-level linguistic processes

Apropos the basal ganglia, the dominant striatum and globus pallidus internus (GPi) have been hypothesised to represent integral components of subcortical language circuitry. Working subcortical language theories, however, have failed thus far to consider a role for the STN in the mediation of linguistic processes, a structure recently defined as the driving force of basal ganglia output. The aim of this research was to investigate the impact of surgically induced functional inhibition of the STN upon linguistic abilities, within the context of established models of basal ganglia participation in language. Two males with surgically induced 'lesions' of the dominant and non-dominant dorsolateral STN, aimed at relieving Parkinsonian motor symptoms, served as experimental subjects. General and high-level language profiles were compiled for each subject up to 1 month prior to and 3 months following neurosurgery, within the drug-on state (i.e., when optimally medicated). Comparable post-operative alterations in linguistic performance were observed subsequent to surgically induced functional inhibition of the left and right STN. More specifically, higher proportions of reliable decline as opposed to improvement in post-operative performance were demonstrated by both subjects on complex language tasks, hypothesised to entail the interplay of cognitive-linguistic processes. The outcomes of the current research challenge unilateralised models of functional basal ganglia organisation with the proposal of a potential interhemispheric regulatory function for the STN in the mediation of high-level linguistic processes.     

Re-appraising contemporary theories of subcortical participation in language: proposing an interhemispheric regulatory function for the subthalamic nucleus (STN) in the mediation of high-level linguistic processes

Apropos the basal ganglia, the dominant striatum and globus pallidus internus (GPi) have been hypothesized to represent integral components of subcortical language circuitry. Working subcortical language theories, however, have failed thus far to consider a role for the STN in the mediation of linguistic processes, a structure recently defined as the driving force of basal ganglia output. The aim of this research was to investigate the impact of surgically induced functional inhibition of the STN upon linguistic abilities, within the context of established models of basal ganglia participation in language. Two males with surgically induced'lesions'of the dominant and non-dominant dorsolateral STN, aimed at relieving Parkinsonian motor symptoms, served as experimental subjects. General and high-level language profiles were compiled for each subject up to 1 month prior to and 3 months following neurosurgery, within the drug-on state (i.e., when optimally medicated). Comparable post-operative alterations in linguistic performance were observed subsequent to surgically induced functional inhibition of the left and right STN. More specifically, higher proportions of reliable decline as opposed to improvement in post-operative performance were demonstrated by both subjects on complex language tasks, hypothesised to entail the interplay of cognitive-linguistic processes. The outcomes of the current research challenge unilateralised models of functional basal ganglia organisation with the proposal of a potential interhemispheric regulatory function for the STN in the mediation of high-level linguistic processes.     

Effects of unilateral subthalamic deep brain stimulation on contralateral arm sequential movements in Parkinson's disease

In Parkinson's disease, unilateral deep brain stimulation (DBS) of the subthalamic nucleus (STN), unlike bilateral stimulation, excludes ipsilateral confounding effects so that the contralateral effects of DBS on motor performance can be investigated alone. Because no kinematic study has yet investigated how unilateral STN-DBS affects the performance of a contralateral fast sequential motor act, we performed a kinematic analysis of the movement duration, switching time and spatial accuracy of a motor arm sequence in 10 parkinsonian patients. Patients were studied without dopaminergic therapy and when they were OFF and ON unilateral STN-DBS. We found that unilateral STN-DBS significantly improved movement time of a motor sequence and the switching time from one sequential step to the next, whereas accuracy deteriorated. We conclude that unilateral STN-DBS improves the performance of contralateral sequential arm movements in patients with Parkinson's disease.     

Improvements in motor behavioral tests during deep brain stimulation of the subthalamic nucleus in rats with different degrees of unilateral parkinsonism

Deep brain stimulation (DBS) improves motor performance in Parkinson's disease (PD) patients. To evaluate the effects of subthalamic nucleus (STN)-DBS on impaired motor behavior, we studied improvements in motor performance after delivery of unilateral stimulation to the STN in rats with mild and severe lesions of the nigrostriatal dopamine system caused by injecting 6-hydroxydopamine into the striatum. The rats were trained and performed motor behavioral tests including rotational behavior test, stepping test, and rotarod test before and after receiving DBS. We demonstrated that stimulation at a current strength of 200 microA, which stopped most of the D-amphetamine-induced rotational behaviors in these two groups, improved movement impairments in both the mild and severe groups and that the improvements in the mild group were significantly better than those in the severe group. More experimental and clinical studies are needed to evaluate the efficiency of STN-DBS for different stages of PD.     

Redefining functional models of basal ganglia organization: Role for the posteroventral pallidum in linguistic processing?

Traditionally the basal ganglia have been implicated in motor behavior, as they are involved in both the execution of automatic actions and the modification of ongoing actions in novel contexts. Corresponding to cognition, the role of the basal ganglia has not been defined as explicitly. Relative to linguistic processes, contemporary theories of subcortical participation in language have endorsed a role for the globus pallidus internus (GPi) in the control of lexical-semantic operations. However, attempts to empirically validate these postulates have been largely limited to neuropsychological investigations of verbal fluency abilities subsequent to pallidotomy. We evaluated the impact of bilateral posteroventral pallidotomy (BPVP) on language function across a range of general and high-level linguistic abilities, and validated/extended working theories of pallidal participation in language. Comprehensive linguistic profiles were compiled up to 1 month before and 3 months after BPVP in 6 subjects with Parkinson's disease (PD). Commensurate linguistic profiles were also gathered over a 3-month period for a nonsurgical control cohort of 16 subjects with PD and a group of 16 non-neurologically impaired controls (NC). Nonparametric between-groups comparisons were conducted and reliable change indices calculated, relative to baseline/3-month follow-up difference scores. Group-wise statistical comparisons between the three groups failed to reveal significant postoperative changes in language performance. Case-by-case data analysis relative to clinically consequential change indices revealed reliable alterations in performance across several language variables as a consequence of BPVP. These findings lend support to models of subcortical participation in language, which promote a role for the GPi in lexical-semantic manipulation mechanisms. Concomitant improvements and decrements in postoperative performance were interpreted within the context of additive and subtractive postlesional effects. Relative to parkinsonian cohorts, clinically reliable versus statistically significant changes on a case by case basis may provide the most accurate method of characterizing the way in which pathophysiologically divergent basal ganglia linguistic circuits respond to BPVP.     

Unmasking psychiatric symptoms after STN deep brain stimulation in Parkinson's disease

Background –  Stereotactic implantation of electrodes for deep brain stimulation (DBS) in the subthalamic nucleus (STN) is a well-established treatment for Parkinson's disease. The treatment gives stable effect over years on the motor symptoms of Parkinson's disease. Psychiatric effects of STN-DBS have attracted increasing attention, with a growing number of reports on psychiatric side effects or exacerbations of known psychiatric disease. However, little is known about the possible unmasking of hidden psychiatric symptoms after surgery.
Aims –  The aim of this clinical commentary is to illustrate unmasking of psychiatric disease by STN-DBS through the presentation of a case from our clinic.
Patient –  A patient with Parkinson's disease underwent implantation of STN stimulation electrodes with good results on his motor symptoms. He did not disclose his previous psychiatric history. Soon after the onset of stimulation he developed affective symptoms with manic, aggressive and depressive behaviour, and also an attempted suicide. The stimulation was reduced and his dopaminergic medication increased after the attempted suicide. His previous history of depression and anxiety was now revealed. He received psychiatric attention, and the affective symptoms resolved. The effect of the stimulation on motor symptoms remained stable.
Conclusions –  The unmasking of previous psychiatric problems after STN stimulation may be an underestimated problem. It is necessary to fully penetrate the psychiatric anamnesis, especially in patients with a strong wish to be operated and a consequent reluctance to reveal previous problems. Patients with a previous history of a psychiatric disorder are not the best candidates for implantation of STN electrodes.     

Biochemical and electrophysiological changes of substantia nigra pars reticulata driven by subthalamic stimulation in patients with Parkinson's disease

To understand the events underlying the clinical efficacy of deep brain stimulation (DBS) of the subthalamic nucleus (STN), electrophysiological recordings and microdialysis evaluations were carried out in the substantia nigra pars reticulata (SNr), one of the two basal ganglia (BG) nuclei targeted by STN output, in patients with Parkinson's disease (PD). Clinically effective STN-DBS caused a significant increase of the SNr firing rate. The poststimulus histogram (PSTH) showed an excitation peak at 1.92-3.85 ms after the STN stimulus. The spontaneous discharge of SNr neurons was driven at the frequency of the stimulation (130 Hz), as shown in the autocorrelograms (AutoCrl). The fast Fourier transform (FFT) analysis showed a peak at 130 Hz, and a less pronounced second one at 260 Hz. Accordingly, in the distribution of the interspike intervals (ISIs), the mode was earlier, and skewness more asymmetric. Biochemically, the increased excitatory driving from the STN was reflected by a clear-cut increase in cyclic guanosine 3',5'-monophosphate (cGMP) levels in the SNr. These results indicate that the beneficial effect of DBS in PD patients is paralleled with a stimulus-synchronized activation of the STN target, SNr. Our findings suggest that, during STN-DBS, a critical change towards a high-frequency oscillatory discharge occurs.     

Subthalamic nucleus stimulation induces deficits in decoding emotional facial expressions in Parkinson's disease

BACKGROUND: Bilateral subthalamic nucleus (STN) stimulation is recognised as a treatment for parkinsonian patients with severe levodopa related motor complications. Although adverse effects are infrequent, some behavioural disturbances have been reported. OBJECTIVE: To investigate the consequences of STN stimulation on emotional information processing in Parkinson's disease by assessing the performance of an emotional facial expression (EFE) decoding task in a group of patients before and after surgery. METHODS: 12 non-demented patients with Parkinson's disease were studied. They were assessed one month before surgery and three months after. Their ability to decode EFEs was assessed using a standardised quantitative task. Overall cognitive function, executive function, visuospatial perception, depression, and anxiety were also measured. Twelve healthy controls were matched for age, sex, and duration of education. RESULTS: Before surgery, the patients showed no impairment in EFE decoding compared with the controls. Their overall cognitive status was preserved but they had a moderate dysexecutive syndrome. Three months after surgery, they had significant impairment of EFE decoding. This was not related to their overall cognitive status or to depression/anxiety scores. Visuospatial perception was not impaired. There was no change in the extent of the dysexecutive syndrome except for a reduction in phonemic word fluency. CONCLUSIONS: Bilateral STN stimulation disturbs negative emotional information processing in Parkinson's disease. The impairment appears specific and unrelated to certain secondary variables. This behavioural complication of STN may have implications for the patient's social life.     

丘脑底核高频刺激治疗帕金森病

目的：研究脑深部刺激（DBS）对帕金森病（PD）的治疗作用。观察术中丘脑底核（STN）刺激对PD震颤,肌僵直、运动缓慢的缓解效果及对语言的影响,探讨植入刺激电极的最佳位置。方法：17例帕金森病患者,利用MRI及微电极导向立体定向方法将刺激电极植入丘脑底核,其靶点：X=11mm,Y=-1mm,Z=-7mm。术中予以高频刺激（频率为150Hz,脉宽为150μz,脉宽为150μs,电压自0.5V开始,逐渐增至6-8V）;其中有2例进行了STN电极永久性植入慢性电刺激,术后随访6-8月,结果：17例术中刺激发现,STN中上部是其刺激、改善病人症状的最佳位置,而电极过深及过外则易引起言语障碍,2例永久性植入慢性电刺激经随访观察对肌僵直的控制非常满意,对运动缓慢有明显改善,并减少美多巴的服药量,UPDRS运动评分下降50%。结论：STN的高频刺激能改善PD的震颤,僵直,运动缓慢等主要症状,是PD慢性刺激的最理想靶点,其中上部是刺激效果的最佳位置。     

双侧丘脑底核脑深部电刺激对PD患者焦虑症状的短期影响

目的探讨双侧丘脑底核脑深部电刺激(STN-DBS)对帕金森病(PD)患者焦虑症状及生活质量的短期影响。方法对上海交通大学附属瑞金医院功能神经外科中心自2017年8月至2019年8月行双侧STN-DBS治疗的39例PD患者,分别于术前、术后1个月和末次随访时进行贝克焦虑自评量表(BAI)、贝克抑郁自评量表(BDI)评分,于术前和术后末次随访时进行帕金森病患者生活质量问卷-8项(PDQ-8)评分,采用统计学方法分析各节点间评分的差异,以及评分改善程度间的相关性;并进一步依据术前BAI评分将患者分为无焦虑组(n=18)、轻度焦虑组(n=10)、中度焦虑组(n=8)和重度焦虑组(n=3),以进行亚组分析。结果(1)39例患者术后1个月及末次随访时的BAI评分[14(8,20)分、9(3,14)分]均明显低于术前[16(9,27)分],术后末次随访时的BDI评分[8(6,16)分]及PDQ-8评分[3(2,6)分]均明显低于术前[15(8,21)分、9(6,13)分],差异均有统计学意义(P<0.05)。(2)相关性分析显示,术后末次随访时的BAI评分较术前的改善程度与BDI评分的改善程度呈正相关关系(rs=0.722,P=0.000),也与术前BDI评分及术前PDQ-8评分呈负相关关系(rs=-0.714,P=0.000;rs=-0.378,P=0.018)。(3)亚组分析显示,轻度焦虑组和中度焦虑组患者中,术后末次随访时的BAI评分均明显低于术前,差异均有统计学意义(P<0.05);轻度焦虑组、中度焦虑组与重度焦虑组患者的术后末次随访时的BAI评分较术前的改善程度均明显高于无焦虑组,差异均有统计学意义(P<0.05)。结论双侧STN-DBS能在短期内显著改善PD患者的焦虑症状,提高其生活质量,提示STN参与了PD患者焦虑症状的神经机制。     

Levodopa response in long-term bilateral subthalamic stimulation for Parkinson's disease.

Subthalamic nucleus deep brain stimulation (STN-DBS) is effective in advanced Parkinson's disease (PD), but its effects on the levodopa response are unclear. We studied the levodopa response after long-term STN-DBS, STN-DBS efficacy and predictive value of preoperative levodopa response to long-term DBS benefit in 33 PD patients with bilateral STN-DBS. Patients were assessed using the Unified Parkinson's Disease Rating Scale preoperatively (with and without medications) and postoperatively (without medications or stimulation, with only medications or stimulation, and with both medications and stimulation). Levodopa response significantly decreased postoperatively by 31.1% at 3 years and 32.3% at 5 years, possibly related to the reduction in medication requirement, direct STN stimulation effect or PD progression. STN-DBS alone significantly improved motor scores (37.2% at 3 years and 35.1% at 5 years) and activities of daily living scores (27.1% at 3 years and 19.2% at 5 years). Anti-PD drugs were significantly reduced by 47.9% at 3 years and 39.8% at 5 years. However, the magnitude of the preoperative response to levodopa did not predict DBS benefit at 3 and 5 years.