Neural correlates of STN DBS-induced cognitive variability in Parkinson disease

BACKGROUND: Although deep brain stimulation of the subthalamic nucleus (STN DBS) in Parkinson disease (PD) improves motor function, it has variable effects on working memory (WM) and response inhibition (RI) performance. The purpose of this study was to determine the neural correlates of STN DBS-induced variability in cognitive performance. METHODS: We measured bilateral STN DBS-induced blood flow changes (PET and [(15)O]-water on one day) in the supplementary motor area (SMA), dorsolateral prefrontal cortex (DLPFC), anterior cingulate cortex (ACC), and right inferior frontal cortex (rIFC) as well as in exploratory ROIs defined by published meta-analyses. STN DBS-induced WM and RI changes (Spatial Delayed Response and Go-No-Go on the next day) were measured in 24 PD participants. On both days, participants withheld PD medications overnight and conditions (OFF vs. ON) were administered in a counterbalanced, double-blind manner. RESULTS: As predicted, STN DBS-induced DLPFC blood flow change correlated with change in WM, but not RI performance. Furthermore, ACC blood flow change correlated with change in RI but not WM performance. For both relationships, increased blood flow related to decreased cognitive performance in response to STN DBS. Of the exploratory regions, only blood flow changes in DLPFC and ACC were correlated with performance. CONCLUSIONS: These results demonstrate that variability in the effects of STN DBS on cognitive performance relates to STN DBS-induced cortical blood flow changes in DLPFC and ACC. This relationship highlights the need to further understand the factors that mediate the variability in neural and cognitive response to STN DBS.     

Intra-operative STN DBS attenuates the prominent beta rhythm in the STN in Parkinson's disease

Power spectra from local field potentials (LFPs) recorded post-operatively from the deep brain stimulation (DBS) macroelectrode show prominence of the beta rhythm (11-30 Hz) in untreated Parkinson's disease (PD). Dopaminergic medication and movement attenuate this beta band in PD. In this pilot study of six sides in four patients, we recorded LFPs from the DBS electrode in untreated PD patients in the operating room. In all cases, there was a peak in the time-frequency spectrogram in the beta frequency range when the patients were at rest, which was associated with attenuation in the same range with movement. The actual frequency range and the strength of the beta peak varied among cases. In two patients, intra-operative constraints permitted recording of LFPs at rest, before and immediately after subthalamic nucleus (STN) DBS. In both patients we documented that STN DBS caused a significant attenuation in power in the beta band at rest that persisted for 15-25 s after DBS had been turned off (P < 0.01). From one case, our data suggest that the beta rhythm attenuation was most prominent within the STN itself. This study shows for the first time that STN DBS attenuates the power in the prominent beta band recorded in the STN of patients with PD. These pilot findings raise the interesting possibility of using this biomarker for closed loop DBS or neuromodulation.     

Correspondence of optimal stimulation and beta power varies regionally in STN DBS for Parkinson disease

IntroductionSubthalamic nucleus deep brain stimulation (STN DBS) for Parkinson disease (PD) normalizes neuronal hypersynchrony in the beta frequency range (13–30 Hz). The spatial correspondence of maximal beta power to the site of optimal stimulation along the DBS lead trajectory has been debated.MethodsWe determined the trajectory locations of the active contact, maximal beta power, and the dorsal border of the STN (DB-STN) in DBS patients. Beta power profiles were measured during intraoperative microelectrode recording (MER). Active contact locations were assigned during blinded, postoperative DBS programming. The DB-STN was identified both electrophysiologically during MER and anatomically on MRI. After grouping DBS trajectories into quadrants relative to the anatomic STN midpoint, we examined regional variations in the relative trajectory locations of the three entities.ResultsSTN DBS significantly improved motor performance for all 13 DBS patients, with active contacts at the DB-STN. Along trajectories passing posterior-medial to the STN midpoint, maximal beta power co-localized with active contacts at the DB-STN (difference Δ = 0.4 ± 1.6 mm, p = 0.57). By contrast, in posterior-lateral trajectories, maximal beta arose within the STN, ventral to active contacts (Δ = 1.9 ± 1.3 mm, p = 0.002). For trajectories anterior to the STN midpoint, maximal beta power co-localized with the DB-STN, while active contacts were ventral to peak beta power (p = 0.05).ConclusionOur findings indicate that co-localization of optimal stimulation and beta power varies by anatomical region in STN DBS for Parkinson disease.     

Dopaminergic basis for deficits in working memory but not attentional set-shifting in Parkinson's disease

Although Parkinson's disease is a common neurodegenerative disorder characterised by its motoric symptoms, there is an increasing recognition of accompanying impairments in cognition that have a profound impact on the quality of life of these patients. These deficits predominantly affect executive function and impairments of working memory have been frequently reported. However, the underlying neurochemical and pathological basis for these deficits are not well understood. In this study, 20 patients were tested 'on' and 'off' levodopa (L-dopa) medication on a task that allowed different aspects of working memory function such as maintenance, retrieval and manipulation to be tested within the same general paradigm as well as on an unrelated test of attentional set-shifting, which is known to be sensitive to deficits in early Parkinson's disease. Compared to healthy volunteers, PD patients were impaired at manipulation more than maintenance or retrieval of information within working memory. The patients were also impaired at the attentional set-shifting task. However, whereas L-dopa ameliorated the working memory deficit in manipulation (improving both accuracy and cognitive response time), it had no effect on the attentional set-shifting impairment. These results confirm that working memory deficits in PD are both psychologically specific and related to dopamine depletion. It is anticipated that greater understanding of these mechanisms will lead to future therapeutic improvements.     

Influence of chronic bilateral stimulation of the subthalamic nucleus on cognitive function in Parkinson's disease

Background: The clinical efficacy of chronic deep brain stimulation in the treatment of parkinsonian patients with severe levodopa-related motor adverse effects has been repeatedly shown. Bilateral subthalamic nucleus (STN) stimulation has been shown to present an advantage over pallidal stimulation as it induces a higher antiakinetic effect and has positive effects on all parkinsonian symptoms. The morbidity of such surgery is usually considered to be very low. However, few studies have extensively examined the effects of chronic STN stimulation on cognitive function. Objective: The aim of the present study was to assess the effects of chronic bilateral STN stimulation on performance in an extensive battery of neuropsychological tests, three months and one year after surgery. Methods: Nine patients with Parkinson's disease were selected for STN electrodes implantation. They underwent a neuropsychological evaluation at one month before and at three months after surgery. Six of them were examined again at one year after surgery. Results: Before surgery, no patient showed cognitive decline. At three months after surgery, no modification was observed for most tasks. The information processing speed tended to improve. There was a significant reduction of the performance in a delayed free recall test and a trend toward a significant reduction of categorial word fluency. At one year after surgery, most task measures did not change. Slight impairment was observed for tasks evaluating executive function. Examination of individual results showed that some patients (30 % at 3 months after surgery) showed an overall cognitive decline. Behavioural changes were also observed in 4 patients with overall cognitive decline in one of them. Conclusion: In general, STN deep brain stimulation can be considered as a significant contribution to the treatment of severe Parkinson's disease However, in some patients it can induce overall cognitive decline or behavioural changes. Received: 4 May 2000 / Received in revised form: 31 January 2001 / Accepted: 6 February 2001     

Using executive heterogeneity to explore the nature of working memory deficits in Parkinson's disease

Idiopathic Parkinson's disease (IPD) is characterised by a triad of motor symptoms, namely bradykinesia, rigidity and resting tremor, although cognitive impairment is a common feature of the disease and has been accepted as one of the strong predictors of quality of life in such patients. Neuropsychological testing in Parkinson's disease often reveals a pattern of cognitive impairment similar to that observed in patients with frontal lobe lesions, although clear differences between the two groups have also often been reported. This apparent inconsistency in the literature may reflect heterogeneity among different groups of patients with Parkinson's disease, although to date this possibility has not been formally addressed. In this study, two groups of patients with Parkinson's disease were assessed on a novel verbal memory task, which allowed different aspects of working memory function such as maintenance, retrieval and manipulation to be tested within the same general paradigm. The two groups were selected according to either good or bad performance on a 'standard', visuospatial test of executive function (The Tower of London Task), but were well matched on all other demographic and cognitive measures tested. The sub-group of Parkinson's disease patients with Tower of London defined executive deficit were specifically impaired at manipulating information within verbal working memory, both compared to controls and to the group of patients with no predefined executive impairments. In contrast, the three groups did not differ in their ability to maintain or retrieve information within verbal working memory. Given the known preferential role of the dorsolateral frontal cortex in higher executive functions, (including both planning and the manipulation of information within working memory), these results suggest that, in a subset of Parkinson's disease patients, it is the frontostriatal circuitry involving this region which is primarily affected, while other components of this circuitry may be relatively spared. The results also suggest that performance on the Tower of London task may prove to be a useful discriminant variable in defining the nature of cognitive heterogeneity in Parkinson's disease.     

丘脑底核脑深部电刺激治疗帕金森病合并抑郁障碍的长期疗效

目的研究丘脑底核（STN）脑深部电刺激（DBS）治疗帕金森病（PD）合并抑郁障碍的长期疗效并探讨其神经机制。方法对15例合并抑郁障碍的PD患者实施STN脑深部电极植入，术后3个月、6个月和12个月进行随访和临床评价。结果术后运动功能症状如肢体僵硬、震颤、运动迟缓和姿势平衡障碍改善良好，停药后PD分级量表运动评分显著下降（P〈0．01）。术后抑郁障碍症状如焦虑、绝望和激越症状改善良好，停药后汉密尔顿抑郁量表评分显著下降（P〈0．05）。结论STN-DBS能显著改善PD的抑郁障碍症状，STN在PD抑郁障碍神经机制中起重要作用。     

Stimulation at dorsal and ventral electrode contacts targeted at the subthalamic nucleus has different effects on motor and emotion functions in Parkinson's disease

Motor and emotion processing depend on different fronto-basal ganglia circuits. Distinct sub-regions of the subthalamic nucleus (STN) may modulate these circuits. We evaluated whether stimulation targeted at separate territories in the STN region would differentially affect motor and emotion function. In a double-blind design, we studied twenty Parkinson's disease patients who had deep brain stimulation (DBS) electrodes implanted bilaterally in the STN. We stimulated either dorsal or ventral contacts of the STN electrodes on separate days in each patient and acquired behavioral measures. Dorsal contact stimulation improved motor function by reducing scores on the Unified Parkinson's Disease Rating Scale and by reducing both reaction time and reaction time variability compared to ventral contact stimulation. By contrast, ventral contact stimulation led to an increase in positive emotion compared to dorsal contact stimulation. These results support the hypothesis that different territories within the STN region implement motor and emotion functions.     

Cortical thickness in visuo-motor areas is related to motor outcomes after STN DBS for Parkinson's disease

IntroductionDeep brain stimulation (DBS) is a widely accepted therapy for Parkinson's disease. While outcome predictors such as levodopa-response are well established, there remains a need for objective and unbiased predictors in clinical practice. We performed an exploratory study to examine whether cortical thickness, derived from preoperative MRI, correlates with postoperative outcome.MethodsUsing freesurfer, we retrospectively measured cortical thickness on the preoperative MRI of 38 patients who underwent bilateral STN-DBS for PD during a 4-year period. The Unified Parkinson Disease Rating motor (UPDRS III) and experiences of daily living subscales (UPDRS II) were collected at baseline and six months after surgery. As an initial analysis, a series of partial correlations was conducted to evaluate the association between postoperative outcome scores and average cortical thickness from predefined regions of interest, adjusting for candidate confounders, without correcting for multiple comparisons. A confirmatory vertex-wise analysis was performed using a cluster-wise correction for multiple comparisons.ResultsBased on the ROI analysis, the strongest correlation with motor outcome was found to be with the left lateral-occipital cortex. Patients with greater cortical thickness in this area presented with greater improvements in motor scores. This relationship was also supported by the vertex-wise analysis. Greater cortical thickness in frontal and temporal regions may be correlated with greater post-operative improvements in UPDRS II, but this was not confirmed in the vertex-wise analysis.ConclusionsOur data indicate that greater cortical thickness in visuo-motor areas is correlated with motor outcomes after DBS for PD. Further prospective investigations are needed to confirm our findings and better-investigate potential image biomarkers.     

1H-MRS experiences after bilateral DBS of the STN in Parkinson's disease

The objective of this study was to evaluate the changes in the concentrations of certain brain metabolites in 13 patients with Parkinson's disease before and after bilateral subthalamic nucleus (STN DBS). The N-acetylaspartate (NAA)/choline (Chol), NAA/creatine (Cr), Chol/Cr ratios were determined by single voxel Proton magnetic resonance spectroscopy (¹H-MRS) studies on 1.0 T unit using short TE stimulated echo acquisition mode (STEAM) sequence. Spectra were obtained from the right and left globus pallidus, and left fronto-basal cortex. The patients were also assessed according to the UPDRS part III, in the “medication-on and off” conditions. Conclusions: after STN DBS cortical NAA/Cho, NAA/Cr ratios increased significantly, which were highly correlated with the significant improvements of the UPDRS scores.     

Stimulation of the subthalamic region at 20 Hz slows the development of grip force in Parkinson's disease

Excessive synchronization of basal ganglia neuronal activity at ~ 20 Hz is characteristic of patients with untreated Parkinson's disease (PD). Correlative evidence suggests that this activity may contribute to bradykinesia. Attempts to demonstrate causality through stimulation imposed synchronization at 20 Hz in the region of the subthalamic nucleus (STN) have had limited success. Finger-tapping is slowed by about 8% and only in those PD patients that have a relatively normal baseline performance in this task. Here we investigate whether greater performance decrements might be seen in a reaction time grip task. We studied 32 sides in 16 patients with PD after overnight withdrawal of medication. Patients were asked to grip as hard and as fast as possible without STN stimulation and during bilateral stimulation at 5 Hz, 10 Hz, 20 Hz, 50 Hz and 130 Hz. Stimulation at 20 Hz slowed the development of force by 14.7 ± 8.3% (P = 0.044) across all patients. Slowing increased by 22 ± 7% (P = 0.005) in those patients with the best performance in the task without stimulation. The effect was frequency specific. These data provide direct interventional evidence of a mechanistic link between excessive neuronal synchronization in the beta range and motor impairment in PD.     

Effects of transcranial direct current stimulation on working memory in patients with Parkinson's disease

OBJECTIVES: Cognitive impairment is a common feature in Parkinson's disease (PD) and is an important predictor of quality of life. Past studies showed that some aspects of cognition, such as working memory, can be enhanced following dopaminergic therapy and transcranial magnetic stimulation. The aim of our study was to investigate whether another form of noninvasive brain stimulation, anodal transcranial direct current stimulation (tDCS), which increases cortical excitability, is associated with a change in a working memory task performance in PD patients. METHODS: We studied 18 patients (12 men and 6 women) with idiopathic PD. The patients performed a three-back working memory task during active anodal tDCS of the left dorsolateral prefrontal cortex (LDLPFC), anodal tDCS of the primary motor cortex (M1) or sham tDCS. In addition, patients underwent two different types of stimulation with different intensities: 1 and 2 mA. RESULTS: The results of this study show a significant improvement in working memory as indexed by task accuracy, after active anodal tDCS of the LDLPFC with 2 mA. The other conditions of stimulation: sham tDCS, anodal tDCS of LDLPFC with 1 mA or anodal tDCS of M1 did not result in a significant task performance change. CONCLUSION: tDCS may exert a beneficial effect on working memory in PD patients that depends on the intensity and site of stimulation. This effect might be explained by the local increase in the excitability of the dorsolateral prefrontal cortex.     

Somatotopic organization in the internal segment of the globus pallidus in Parkinson's disease

Ablation or deep brain stimulation in the internal segment of the globus pallidus (GPi) is an effective therapy for the treatment of Parkinson's disease (PD). Yet many patients receive only partial benefit, including varying levels of improvement across different body regions, which may relate to a differential effect of GPi surgery on the different body regions. Unfortunately, our understanding of the somatotopic organization of human GPi is based on a small number of studies with limited sample sizes, including several based upon only a single recording track or plane. To fully address the three-dimensional somatotopic organization of GPi, we examined the receptive field properties of pallidal neurons in a large cohort of patients undergoing stereotactic surgery. The response of neurons to active and passive movements of the limbs and orofacial structures was determined, using a minimum of three tracks across at least two medial-lateral planes. Neurons (3183) were evaluated from 299 patients, of which 1972 (62%) were modulated by sensorimotor manipulation. Of these, 1767 responded to a single, contralateral body region, with the remaining 205 responding to multiple and/or ipsilateral body regions. Leg-related neurons were found dorsal, medial and anterior to arm-related neurons, while arm-related neurons were dorsal and lateral to orofacial-related neurons. This study provides a more detailed map of individual body regions as well as specific joints within each region and provides a potential explanation for the differential effect of lesions or DBS of the GPi on different body parts in patients undergoing surgical treatment of movement disorders.     

Long-term effects of bilateral deep brain stimulation of the subthalamic nucleus on depression in patients with Parkinson's disease

ObjectiveTo study the long-term effects of deep brain stimulation (DBS) of the bilateral subthalamic nucleus (STN) on depression in patients with Parkinson's disease (PD) and to discuss the mechanism.MethodsA STN–DBS group (n = 27) and anti-Parkinson's medication control group with paired designing were set up. The evaluation of the depression and motor function was performed a total of six times. Depression was evaluated by the Self-Rating Depression Scale (SDS) and Hamilton Rating Scale for Depression (HAMD). Motor function was evaluated by the third part of the Unified Parkinson's Disease Rating Scale (UPDRS-III).ResultsCompared with the preoperative and the medication control group, the UPDRS-III scores of the STN–DBS group decreased remarkably within 18 months postoperatively (P ≤ 0.001), and the SDS scores decreased notably within 6 months postoperatively (P ≤ 0.05), and the HAMD scores decreased notably within 3 months postoperatively (P ≤ 0.05). The UPDRS-III scores were strongly correlated with their SDS scores within 6 months postoperatively (P ≤ 0.05), especially at 5 weeks postoperation (P ≤ 0.001). UPDRS-III scores were also strongly correlated with HAMD scores at 5 weeks postoperation (P ≤ 0.05). The mean value of the bilateral voltages was obviously correlated with SDS and HAMD scores (P ≤ 0.05) within 18 months postoperatively.ConclusionThe improvement in motor symptoms resulting from STN–DBS can improve depression in PD patients, but its long-term effects were unremarkable. Within the treatment range, the higher the mean value of bilateral voltages then the more severe was the depression in PD patients.     

Clinical outcomes of PD patients having bilateral STN DBS using high-field interventional MR-imaging for lead placement

Objective

Recently, an iMRI-guided technique for implanting DBS electrodes without MER was developed at our center. Here we report the clinical outcomes of PD patients undergoing STN DBS surgery using this surgical approach.

Methods

Consecutive PD patients undergoing bilateral STN DBS using this method were prospectively studied. Severity of PD was determined using the UPDRS scores, Hoehn and Yahr staging score, stand-sit-walk testing, and the dyskinesia rating scale. The primary outcome measure was the change in UPDRS III off medication score at 6 months. DBS stimulation parameters, adverse events, levodopa equivalent daily dose (LEDD), and DBS lead locations were also recorded. Seventeen advanced PD patients (9M/8F) were enrolled from 2007 to 2009.

Results

The mean UPDRS III off medication score improved from 44.5 to 22.5 (49.4%) at 6 months (p = 0.001). Other secondary outcome measures (UPDRS II, III on medication, and IV) significantly improved as well (p < 0.01). LEDD decreased by an average of 24.7% (p = 0.003). Average stimulation parameters were: 2.9 V, 66.4 μs, 154 Hz.

Conclusion

This pilot study demonstrates that STN DBS leads placed using the iMRI-guided method results in significantly improved outcomes in PD symptoms, and these outcomes are similar to what has been reported using traditional frame-based, MER-guided stereotactic methods.     

丘脑底核脑深部刺激术治疗帕金森病的手术方法和疗效分析

目的 总结帕金森病(PD)脑深部刺激术(DBS)治疗的手术方法和效果。方法 对25例帕金森病患者进行了丘脑底核DBS治疗,其中单侧17例,双侧8例。采用磁共振扫描结合微电极记录技术进行靶点定位。术后用UPDRS运动评分评价刺激效果。结果 25例PD患者术后随访5～34个月,平均8.3个月。脉冲发生器开启时,在“关”状态下,UPDRS运动评分改善率50.2％;在“开”状态下,UPDRS运动评分改善率20.7％,未发现任何并发症。结论 丘脑底核DBS是改善PD患者运动功能较为理想的治疗方法。     

Localization of motor and verbal fluency effects in subthalamic DBS for Parkinson's disease

IntroductionSubthalamic nucleus deep brain stimulation (STN DBS) improves cardinal motor symptoms of Parkinson's disease (PD) but can worsen verbal fluency (VF). An optimal site of stimulation for overall motor improvement has been previously identified using an atlas-independent, fully individualized, field-modeling approach. This study examines if cardinal motor components (bradykinesia, tremor, and rigidity) share this identified optimal improvement site and if there is co-localization with a site that worsens VF.MethodsAn atlas-independent, field-modeling approach was used to identify sites of maximal STN DBS effect on overall and cardinal motor symptoms and VF in 60 patients. Anatomic coordinates were referenced to the STN midpoint. Symptom severity was assessed with the MDS-UPDRS part III and established VF scales.ResultsSites for improved bradykinesia and rigidity co-localized with each other and the overall part III site (0.09 mm lateral, 0.93 mm posterior, 1.75 mm dorsal). The optimal site for tremor was posterior to this site (0.10 mm lateral, 1.40 mm posterior, 1.93 mm dorsal). Semantic and phonemic VF sites were indistinguishable and co-localized medial to the motor sites (0.32 mm medial, 1.18 mm posterior, 1.74 mm dorsal).ConclusionThis study identifies statistically distinct, maximally effective stimulation sites for tremor improvement, VF worsening, and overall and other cardinal motor improvements in STN DBS. Current electrode sizes and voltage settings stimulate all of these sites simultaneously. However, future targeted lead placement and focused directional stimulation may avoid VF worsening while maintaining motor improvements in STN DBS.     

Effects of stimulation of the subthalamic area on oscillatory pallidal activity in Parkinson's disease

The pattern of neuronal discharge within the basal ganglia is disturbed in Parkinson's disease (PD). In particular, there is a tendency for neuronal elements to synchronise at around 20 Hz in the absence of dopaminergic treatment, whereas this activity can be replaced by spontaneous synchronisation at much higher frequencies (>70 Hz) following dopaminergic treatment [J. Neurosci. 21 (2001) 1033; Brain 126 (2003) 2153]. In two PD patients (3 sides), we show that stimulating the subthalamic area at around 20 Hz exacerbates synchronisation at similar frequencies in the globus pallidus interna, the major output structure of the human basal ganglia. In contrast, stimulating the subthalamic area at >70 Hz suppresses pallidal activity at about 20 Hz. Clinically, stimulation of the subthalamic area at similar high frequencies reverses parkinsonism and forms the basis of therapeutic deep brain stimulation in PD. The results point to a possible common mechanism by which both dopaminergic treatment associated synchronisation of subthalamic activity at very high frequency and synchronisation imposed by therapeutic stimulation of the subthalamic area inhibit an abnormal and potentially deleterious synchronisation of basal ganglia output at around 20 Hz. If this activity is unchecked by synchronisation at higher frequency, then pathological 20-Hz oscillations may cascade through the basal ganglia, increasing at subsequent levels of processing.     

Alterations in working memory as a function of leukoaraiosis in dementia

Dementia research suggests executive dysfunction is best understood within the context of disease-specific neuropathology. Leukoaraiosis (LA) results in executive dysfunction yet little is known about its impact on specific aspects of working memory (WM). This study aimed to investigate the relationship between MRI LA severity and WM in dementia. A visual rating scale was used to assign patients with dementia into groups with minimal-mild LA (Low LA; n=34) and moderate-severe LA (High LA; n=32). A modified Digit Span Backward Task consisting of 3-, 4-, and 5-span trials measured specific components of WM. Short-term storage and rehearsal in WM were assessed by the total number of digits reported regardless of recall order (ANY-ORDER; e.g., 47981 recalled '18943', score=4). Mental manipulation in the form of disengagement and temporal re-ordering was assessed by the total number of digits recalled in correct position (SERIAL-ORDER; e.g., 47981 recalled '18943', score=3). There was no difference between LA groups on ANY-ORDER comparisons. The High LA group obtained lower SERIAL-ORDER scores than the Low LA group. Stepwise regression analyses were conducted that first entered MMSE scores then composite z-scores reflecting executive functioning, language and memory. ANY-ORDER performance variance was explained solely by dementia severity. SERIAL-ORDER performance variance was further explained by executive dysfunction. Results suggest that high degrees of LA do not interfere with immediate (digit) recall but do interfere with disengagement and temporal re-ordering. LA may disconnect the frontal lobes from subcortical and cortical structures that form the neuronal networks critical for these WM functions.     

刺激术和毁损术在双侧立体定向手术治疗帕金森病中的比较

目的比较脑深部刺激术和毁损术在双侧立体定向手术治疗帕金森病中的优缺点。方法69例帕金森病病人进行了双侧手术治疗,其中同期双侧丘脑底核(STN)脑深部刺激术(DBS)11例,同期一侧苍白球腹后部毁损术(PVP),另一侧STNDBS3例,分期一侧PVP或腹中间核(Vim)毁损术、另一侧STN或VimDBS9例;分期双侧PVP或Vim毁损术41例,同期双侧PVP5例。平均随访9.3个月。结果UPDRS评分显示刺激术和毁损术均能显著改善对侧肢体震颤、僵硬和运动迟缓症状,双侧刺激术还能改善步态和姿势症状,但双侧毁损术可加重语言、吞咽及流涎等症状,并发症较高。结论双侧DBS是具有双侧症状的帕金森病病人手术治疗的最佳术式,双侧毁损术并发症较高,应严格慎重采用。