Motor and Cognitive Sequelae of Unilateral Pallidotomy in Intractable Parkinson's Disease: Electronic Measurement of Motor Steadiness is a Useful Outcome Measure

This study examined the short-term motor and cognitive sequelae of unilateral posterolateral pallidotomy for patients with intractable Parkinson's Disease (PD). Unique to this study was the inclusion of electronic motor steadiness instrumentation among pre- and postsurgical assessment procedures. Fifteen PD patients underwent right-sided surgery and 10 underwent left-sided surgery; patients were evaluated 1 month presurgery and approximately 3 months postsurgery. Motorically, there were no significant changes in grooved pegboard or maze-drawing performances, but patients evidenced significantly improved steadiness, particularly in the hand contralateral to the side of surgery. Cognitively, there were no significant decrements on postsurgery composite variables comprised of well-known tests of attention, executive functioning, delayed memory or recognition memory; these findings were similar for patients with either left- or right-sided surgery. There was, however, a significant change in language abilities among a subset of patients. This change was evident in the decline in verbal fluency in PD patients who underwent left-sided pallidotomy, a finding that has consistently emerged in pallidotomy outcome studies. This decline is discussed in terms of evidence that suggests that the basal ganglia consist of several separate, but parallel circuits, some of which are important for cognition.     

Unilateral pallidotomy in PD: a controlled study of cognitive and behavioral effects. The Netherlands Pallidotomy Study (NEPAS) group

OBJECTIVE: To investigate whether unilateral pallidotomy affects cognitive and behavioral functioning. METHODS: At baseline and after 6 months we assessed neuropsychological functioning in 35 patients with advanced PD. After baseline examination, patients were randomized to pallidotomy within 1 month (6 left-sided, 13 right-sided) or to pallidotomy after follow-up assessment 6 months later (n = 16; control group). We performed neuropsychological tests of language, visuospatial function, memory, attention, and executive functions. Self ratings and proxy ratings of memory problems and dysexecutive symptoms were also collected. RESULTS: No significant differences over time were found between pallidotomy and control groups, with the exception of a decrease of verbal fluency in the left-sided pallidotomy group. CONCLUSIONS: Unilateral pallidotomy is relatively safe with respect to cognition and behavior. Left-sided pallidotomy may lead to minor deterioration in verbal fluency. The sample size of this study is too small, however, to rule out the possibility of infrequent but clinically important side effects.     

Comparison of neuropsychological outcomes after selective amygdalohippocampectomy versus anterior temporal lobectomy

Transsylvian selective amygdalohippocampectomy (TSA) is an operative technique designed to spare unaffected brain tissue during surgical treatment for mesial temporal lobe epilepsy. In contrast to standard anterior temporal lobectomy (ATL), the advantages of TSA with respect to postoperative cognitive outcome are equivocal. We compared cognitive function before and after surgery in 49 patients with unilateral mesial temporal lobe seizures who underwent either ATL (n=17) or TSA (n=32). All patients received neuropsychological testing before and 1 year after surgery. The intelligence quotient (IQ) increased postoperatively in both surgical groups. Memory evaluation in the ATL group revealed a postoperative decline in nonverbal memory after right-sided resection and a postoperative decline in verbal memory after left-sided resection. In the TSA group, there was a slight postoperative decline only in verbal memory after left-sided resection, but other memory function was well preserved. In particular, there was significant postoperative improvement in verbal memory after right-sided resection. Overall, memory function was better preserved in the TSA group than in the ATL group.     

Risk to verbal memory following anterior temporal lobectomy in patients with severe left-sided hippocampal sclerosis

BACKGROUND: Previous investigations indicate low risk for memory loss following anterior temporal lobectomy (ATL) in patients with severe hippocampal sclerosis (HS) compared with patients with mild HS. However, these conclusions have been established primarily with group-level analyses. OBJECTIVE: To investigate individual base rate risk for verbal memory loss following ATL in patients who have pathologically verified mild, moderate, or severe HS. PATIENTS AND METHODS: One hundred fifteen patients with unilateral temporal lobe epilepsy (68 with left-sided and 47 with right-sided epilepsy) were included. Acquisition, retrieval, and recognition components of verbal memory, as measured by the California Verbal Learning Test, were assessed before and after ATL. Postoperatively, the degree of neuronal loss and reactive gliosis of the hippocampus was assessed via a 3-tiered rating system establishing mild, moderate, and severe pathologic features. Patients with preoperative magnetic resonance imaging-based evidence of lesions outside the mesial temporal area (side of surgical resection) were excluded. RESULTS: Neither seizure laterality nor severity of HS was associated with preoperative verbal memory performance. Postoperatively, the left-sided ATL group demonstrated significant decline across the acquisition (P<.01), retrival (P<.001), and recognition (P<.001) verbal memory components compared with the right-sided ATL group. Patients who underwent left-sided ATL and had mild HS displayed the largest magnitude and percentage proportion of postoperative decline across all verbal memory components. However, 28 (48%) of the 58 patients who underwent left-sided ATL and who had moderate and severe HS displayed statistically reliable declines on retrieval aspects of verbal memory. Most patients undergoing right-sided ATL, regardless of the extent of hippocampal pathologic features, displayed no postoperative memory change. CONCLUSIONS: Substantial individual heterogeneity of memory outcome exists across groups of patients undergoing ATL, with various degrees of pathologically verified HS. Patients undergoing left-sided ATL who have mild HS seem at greatest risk for broad-spectrum verbal memory decline. However, when examining outcome on a patient-by-patient basis, many patients undergoing left-sided ATL who have moderate to severe HS were also vulnerable to verbal memory loss. This risk seems selective to a retrieval-based aspect of verbal memory.     

微电极引导的苍白球腹后部毁损术与中医药治疗帕金森病的对比研究

目的 :通过微电极引导的苍白球腹后部毁损术和中医药疗法治疗帕金森病的对比研究 ,探讨手术疗法和中医药疗法各自的疗效特点和治疗适应证。方法 :应用微电极引导的苍白球腹后部毁损术治疗帕金森病 34例 ,手术包括同期双侧、分期双侧和单侧手术。针刺配合中药治疗帕金森病 5 6例。Webster帕金森病功能障碍记分法评分 ,将治疗前后和两组之间治疗结果进行对比。结果 :手术治疗组 34例帕金森病病人中 ,有 33例患者在手术过程中震颤、僵直、运动迟缓等主要症状均有不同程度的缓解 ,手术后这些症状也持续好转 ,但其症状缓解程度在不同的病人中有所不同。Webster帕金森病功能障碍记分法评分 ,术后 1周进步率为 5 0 %～ 99%者 2 6例 ,1%～ 49%者 7例 ,<1%者 1例 ,总有效率 97%。中医药治疗组 80 %以上的患者治疗一个月后主观症状改善 ,主要体征好转 ,基本生活能力得到提高。治疗 3个月后Webster帕金森病功能障碍记分法评分 ,进步率为 5 0 %～ 99%者 6例 ,1%～ 49%者 39例 ,<1%者 11例 ,总有效率为 80 4%。两组患者治疗前、后评分结果进行t检验 ,P <0 0 1,两组之间治疗结果的总有效率进行 χ2 检验校正 ,P <0 0 5。结论 :微电极引导的苍白球腹后部毁损术和中医药治疗帕金森病均可取得较为满意的疗效。手术组对     

Cognitive and behavioral changes after unilateral posteroventral pallidotomy: relationship with lesional data from MRI.

We investigated cognitive and behavioral changes after unilateral posteroventral pallidotomy, and their relationship with lesion size and location as identified in magnetic resonance image quantitative analysis. Fifteen consecutive patients with Parkinson's disease were assessed neuropsychologically before and after unilateral posteroventral pallidotomy (five right and 10 left). Immediate postsurgery evaluation (1 week) demonstrated significant worsening of memory, motor learning, motor speed, and verbal fluency. In the 3-month follow up, learning, memory, and speed returned to the presurgical level, but verbal fluency remained below the baseline. Significant improvements were observed in visuospatial functions and obsessive-compulsive behavior. Lesional volume did not correlate with neuropsychologic changes. Left lesions produced more impairment in verbal fluency than right-sided lesions. Regression analysis identified two lesional areas in the pallidum mediale internum. These regions accounted for 68% of the variance in the visuospatial changes.     

GPi pallidotomy for Parkinson's disease with drug-induced psychosis

Levodopa-induced psychosis may seriously threaten the ability of patients with Parkinson's disease (PD) to continue leading an independent life. A retrospective assessment of the therapeutic effects of the globus pallidus internus (GPi) pallidotomy on the activities of daily living (ADL) of seven PD patients presenting with mild or moderate degrees of psychosis was carried out. Their scores according to the Unified Parkinson's Disease Rating Scale (UPDRS) Part I-2 (maximum=4) were 2 or 3 (mean +/- SD=2.4 +/- 0.5). Bilateral procedure was needed in 5 out of 7 patients to obtain sufficient improvement of motor symptoms. At 3 months after surgery, UPDRS part III motor scores in the 'off' state were significantly decreased and motor fluctuations were abolished. Nevertheless, their score of Schwab and England (S-E) ADL scale scores responded poorly to the surgery, while the scores in other 12 patients without psychosis was significantly improved after pallidotomy. The data indicate that GPi pallidotomy ameliorates the motor symptoms in patients with drug-induced psychosis (DIP), but has no significant impact on their consequent daily activities. A regression model for all 19 patients who underwent pallidotomy revealed that postoperative S-E scale was affected by the preoperative UPDRS Part I-2 rather than by Part III motor score. The present study suggested that DIP, even if its degree is not severe, may be a limiting factor of the therapeutic potential of pallidotomy in patients with PD.     

Unilateral pallidotomy versus bilateral subthalamic nucleus stimulation in PD

Abstract Objective To compare the cognitive and behavioural effects of unilateral pallidotomy and bilateral subthalamic nucleus (STN) stimulation. Methods After baseline examination 34 patients were randomly assigned to unilateral pallidotomy (4 left-sided, 10 right-sided) or bilateral STN stimulation (n=20). At baseline and six and twelve months after surgery we administered neuropsychological tests of language, memory, visuospatial function, mental speed and executive functions. Also a depression rating scale, and self and proxy ratings of memory and dysexecutive symptoms were administered. Results Six months after surgery, the STN group and the pallidotomy group differed significantly in change from baseline in number of errors on two tests of executive functioning. After 12 months the STN group reported less positive affect compared with baseline than the pallidotomy group. One patient in the STN group showed an overall cognitive deterioration due to complications. Conclusions Although we need larger groups to draw firm conclusions, our results suggest that bilateral STN stimulation has slightly more negative effects on executive functioning than unilateral pallidotomy.     

GPi pallidotomy for Parkinson's disease with drug-induced psychosis

Levodopa-induced psychosis may seriously threaten the ability of patients with Parkinson's disease (PD) to continue leading an independent life. A retrospective assessment of the therapeutic effects of the globus pallidus internus (GPi) pallidotomy on the activities of daily living (ADL) of seven PD patients presenting with mild or moderate degrees of psychosis was carried out. Their scores according to the Unified Parkinson's Disease Rating Scale (UPDRS) Part I-2 (maximum=4) were 2 or 3 (mean±SD=2.4±0.5). Bilateral procedure was needed in 5 out of 7 patients to obtain sufficient improvement of motor symptoms. At 3 months after surgery, UPDRS part III motor scores in the ‘off’ state were significantly decreased and motor fluctuations were abolished. Nevertheless, their score of Schwab and England (S–E) ADL scale scores responded poorly to the surgery, while the scores in other 12 patients without psychosis was significantly improved after pallidotomy. The data indicate that GPi pallidotomy ameliorates the motor symptoms in patients with drug-induced psychosis (DIP), but has no significant impact on their consequent daily activities. A regression model for all 19 patients who underwent pallidotomy revealed that postoperative S–E scale was affected by the preoperative UPDRS Part I-2 rather than by Part III motor score. The present study suggested that DIP, even if its degree is not severe, may be a limiting factor of the therapeutic potential of pallidotomy in patients with PD.     

微电极引导的苍白球鼠损术对帕金森病患者认知功能的近期影响

目的：了解微电极引导的腹侧苍白球毁损术（PVP）对帕金森病（PD）患者认知功能的影响,方法：对接受PVP治疗的20例PD患者手术前后进行认知功能检查,临床记忆量表、线方向判断测验、言主流畅性及简明精神状态量表检查。结果：左侧PVP患者术后临床记忆量表联想学习分测验成绩较术前显著减退（P＜0．05）,其余记忆分测验、记忆商以及其他认知检查手术前后无显著改变（P＞0．05）;右侧PVP患者术后较术前各项检查成绩无明显改变（P＞0．05）,手术后运动功能较术前显著改善（P＜0．05）。结论左侧苍白球参与了语言记忆,PVP对所检查的认知功能影响轻微。     

Pallidotomy versus pallidal stimulation

Both posteroventral pallidotomy and pallidal deep brain stimulation (DBS) have a documented effect on Parkinsonian symptoms. DBS is more costly and more laborious than pallidotomy. The aim of this study was to analyse the respective long-term effect of each surgical procedure on contralateral symptoms in the same patients. Five consecutive patients, two women and three men, who at first surgery had a mean age of 64 years and a mean duration of disease of 18 years, received a pallidotomy contralateral to the more symptomatic side of the body. At a mean of 14 months later, the same patients received a pallidal DBS on the side contralateral to the pallidotomy. All patients had on-off phenomena and dyskinesias. There were three left-sided and two right-sided pallidotomies, and, subsequently, two left-sided and three right-sided pallidal DBS. The latest evaluation was performed 37 months (range 22-60) after the pallidotomy and 22 months (range 12-33) after the pallidal DBS. Mean UPDRS motor score pre-operatively was 49 and at last follow-up 33 (32.7% improvement, p<0.05). Appendicular items 20-26 contralateral to pallidotomy remained improved more significantly than contralateral to DBS. Dyskinesia scores were also improved more markedly contralateral to the pallidotomy. Two patients exhibited moderate dysarthria and one patient severe dysphonia following DBS. Symptoms contralateral to the chronologically older pallidotomy, especially dyskinesias, rigidity and tremor, were still more improved than symptoms contralateral to the more recent pallidal DBS, despite numerous post-operative patient visits to optimise stimulation parameters.     

Cognitive effects of unilateral posteroventral pallidotomy: a 4-year follow-up study.

We assessed the long-term neuropsychological effects of unilateral posteroventral pallidotomy in Parkinson's disease. Eleven Parkinson's disease patients, from an original cohort of 15 consecutive patients who underwent pallidotomy, were evaluated. A neuropsychological battery was administered to each patient before (3 days) and after (3 months and 4 years) surgery during the effects of levodopa. The following tests were administered: Rey's Auditory-Verbal Learning Test, Visual Associative Learning test from the Wechsler Memory Scale-Revised, Luria's motor alternation, Benton's Judgment of Line Orientation, Trail Making, phonetic verbal fluency, Stroop test, Petrides' working memory tasks, Beck's depression questionnaire and the Maudsley obsessional-compulsive inventory. In the 3-month postoperative assessment, there was a significant worsening in phonetic verbal fluency and an improvement in Benton's Judgment of Line Orientation test. In the 4-year follow-up assessment, phonetic verbal fluency and Benton's Judgment of Line Orientation test returned to baseline scores. Although there was no significant difference between pre- and postsurgical scores for long-term visual associative memory, there was a significant deterioration between 3-month and 4-year follow-up performances. Our results suggest that unilateral posteroventral pallidotomy may produce transient changes in prefrontal and visuospatial functions, but there is no evidence of permanent neuropsychological effects.     

Neuropsychological changes 1-year after subthalamic DBS in PD patients: A prospective controlled study

ObjectiveThis study aimed at investigating the neuropsychological effect of DBS of the Subthalamic Nucleus in patients with advanced Parkinson's disease (PD).MethodsA standardized neuropsychological test battery, assessing reasoning, memory and executive functions, was administered to 27 PD patients who underwent DBS-STN (DBS group) and to a matched control group of 31 PD patients under optimal medical treatment (MED group). Patients were evaluated at baseline and at the end of 1 year.ResultsChange score analysis (T1 minus T0 scores) demonstrated a significant decline in phonemic verbal fluency in the DBS group compared with the MED group (p < 0.005), while there were no significant changes between the two groups for the other cognitive tests. Single cases analysis by means of multivariate normative comparisons revealed that 4 out of 27 DBS patients (15%) showed cognitive deterioration one year post surgery. These patients were significantly more compromised from a motor standpoint (UPDRS, section III) than the 23 DBS PD patients who had no cognitive decline post surgery.ConclusionResults of this prospective controlled-study showed that phonemic verbal fluency declined one year after DBS-STN, while the other cognitive domains did not change significantly. Nevertheless, single case analysis highlighted the fact that a subgroup comprising 15% of DBS-STN patients (4/27) showed significant cognitive decline 1 year after surgery.     

Effects of pallidotomy and bilateral subthalamic stimulation on cognitive function in Parkinson disease

Unilateral pallidotomy and bilateral subthalamic deep brain stimulation (STN-DBS) for Parkinsons disease (PD) have demonstrated a positive effect on motor functions. However, further studies are needed of the unintended cognitive effects accompanying these new surgical procedures. We studied the consequences of unilateral pallidotomy and STN-DBS on cognitive function in a controlled comparative design. Sixteen consecutive PD patients were assessed before and 6 months after unilateral pallidotomy (n = 8) and bilateral STN-DBS (n = 8). The same assessments were performed in a control group of eight non-operated matched PD patients recruited from surgery candidates who refused operation. The neuropsychological battery consisted of test measuring memory, attention, arithmetic, problem solving and language, as well as visuospatial, executive and premotor functions. An analysis of variance (factors time and treatment) was applied. No statistically significant differences were found in the presurgical evaluation of clinical and demographic data for the three treatment groups. The controlled comparison between presurgical and postsurgical performance revealed no significant changes in the cognitive domains tested in the pallidotomy group. The STN-DBS group showed a selective significant worsening of semantic verbal fluency (p = 0.005). This controlled comparative study suggests that neither unilateral pallidotomy nor bilateral STN-DBS have global adverse cognitive consequences, but bilateral STN-DBS may cause a selective decrease in verbal fluency.     

丘脑底核电刺激治疗苍白球毁损术后的帕金森病(12例报告)

目的探讨帕金森病(Parkinson's disease,PD)苍白球腹后部毁损术(posteroventral pallidotomy,PVP)后再行丘脑底核(subthalamic nucleus,STN)脑深部电刺激术(deep brain stimulation,DBS)的可行性、术中电生理学特点和治疗结果。方法应用MR和微电极记录技术进行靶点定位,对12例单侧PVP术后症状再次加重的PD患者实施STN-DBS手术,其中4例行毁损灶对侧的STN-DBS,8例行双侧STN-DBS。结果STN-DBS对本组12例PD患者症状有不同程度的改善,双侧STN-DBS的效果尤为明显,术后3个月的UPDRS运动及ADL评分较术前明显减少(P<0．05或0．01),美多巴的用量明显减少(P<0．01),无明显术后并发症。术中电生理记录显示毁损灶同侧的细胞放电明显低于正常情况。结论曾行单侧PVP的PD患者如面临二次手术,可以选择DBS手术,以双侧STN的DBS效果最好,可减少药物用量。     

Outcomes following staged bilateral pallidotomy in advanced Parkinson's disease

The authors assessed clinical outcome for up to one year after staged bilateral pallidotomy in 14 patients with advanced PD. One year after surgery, dyskinesias were virtually abolished and there were significant reductions in "off" time (67%) and activities of daily living "off" scores (24%), as well as nonsignificant reduction in "off" motor score (39%); "on" scores were unchanged. One patient developed a visual field deficit; two had transient confusion. Staged bilateral pallidotomy improves motor function in selected patients with advanced PD.     

Correlation between 1H MRS and memory before and after surgery in mesial temporal lobe epilepsy with hippocampal sclerosis

PURPOSE: Proton magnetic resonance spectroscopy (1H MRS), which can demonstrate neuronal loss and gliosis, may be used as a sensitive tool for lateralization of temporal lobe epilepsy (TLE). Although the correlation between the memory functions and 1H MRS has been investigated, its predictive value after surgery has not been studied previously. This study evaluated memory and 1H MRS values of medically intractable patients with mesial TLE and hippocampal sclerosis (MTLE-HS) before and after selective amygdalohippocampectomy (SAH). METHODS: Twenty-two patients underwent memory tests and 1H MRS investigation before and 6 months after SAH and were compared with nine control subjects. RESULTS: The 1H MRS scores were found to be significantly low on the pathological side of the patients. Both right-sided 1H MRS of right TLE and left-sided 1H MRS values of left TLE patients were correlated only with verbal memory scores. Statistical analysis did not reveal any significance for nonverbal memory scores for both TLE groups on either side, which showed no significant correlation between material specificity and 1H MRS findings. Conversely, regression analyses demonstrated that high right- and low left-sided 1H MRS values obtained before surgery may predict a decline in verbal learning scores after surgery. CONCLUSIONS: 1H MRS can be considered as a useful tool to determine the lateralization in patients with MTLE-HS before the surgery. Although only a weak relation exists between the MRS values and memory scores, presurgical MRS scores may be predictive for a possible deterioration in verbal memory after surgery. However, further studies with higher numbers of cases are needed for confirmation of the results.     

Hemispheric asymmetries in motor function: I. Left-hemisphere specialization for memory but not performance

Patients with unilateral brain lesions of vascular origin were administered tests designed to determine if left-hemisphere specialization in manual-sequence tasks involves memory for these sequences, or performance of them, or both. Patients with left-sided lesions were worse than patients with right-sided lesions on two tasks requiring the recall of hand positions. Whereas patients with left-sided lesions showed a trend towards being worse on speeded performance of an already learned manual sequence, in both groups on this task there were a large number of failures to remember the sequence. When memory demands were better controlled by providing a model during the speeded performance task, there were no group differences. It is proposed that there is left-hemisphere specialization for memory but not performance of such motor tasks.     

Effects of unilateral pallidotomy on voluntary movement, and simple and choice reaction times in Parkinson's disease.

We studied the effects of unilateral pallidotomy on motor execution and reaction times in patients with moderately advanced Parkinson's disease (PD). Twelve consecutive patients (7 men, 5 women; all right-handed) underwent left-side microelectrode-guided pallidotomy. In addition to clinical rating, reaction time (RT) tests and repetitive movements of the contralesional hand/arm were carried out at baseline and 2 to 3 months after surgery while patients were on optimal medical regimens (on period). The initiation time in both simple reaction time (SRT) and choice reaction time (CRT) improved significantly after pallidotomy (P < 0.05), whereas no effect was observed on the choice processing time, which was calculated by subtracting the mean value of the onset of SRT from that of CRT. Pallidotomy resulted in significant improvement of repetitive movements such as hand pronation/supination and finger-tapping (P < 0.002, P < 0.005, respectively). Improvements in RT tests and repetitive movements suggest that pallidotomy may enhance attention and motor function. These effects are probably mediated through the pallido-thalamic-cortical neural circuitry.     

Memory outcome 2 years after anterior temporal lobectomy in patients with drug-resistant epilepsy

PURPOSE: Memory decline is often observed after anterior temporal lobectomy (ATL), particularly in patients with dominant hemisphere resections. However, the follow-up length has been 1 year or less in most studies. Our aims were to examine postoperative memory changes over a longer period and to identify baseline demographic and clinical predictors of memory outcome. METHODS: We administered material-specific memory tests at baseline, and 1 and 2 years after surgery to 82 consecutive right-handed patients (52% males) who underwent ATL for drug-resistant temporal lobe epilepsy (TLE) (35 left, 47 right) after a non-invasive presurgical protocol. Repeated measures multivariate analysis of variance (RM-MANOVA) was used to examine the relationship between changes in memory tests scores over time and side of TLE and pathology. Also, standardized residual change scores were calculated for each memory test and entered in multiple linear regression models aimed at identifying baseline predictors of better memory outcome. RESULTS: RM-MANOVA revealed a significant change in memory test scores over time, with an interaction between time and side of surgery, as 2 years after surgery patients with RTLE were improved while patients with LTLE were not worse as compared with baseline. Pathology was not associated with changes in memory scores. In multiple regression analysis, significant associations were found between right TLE and greater improvement in verbal memory, younger age and greater improvement in visuospatial memory, and male gender and greater improvement in both verbal and visuospatial memory. CONCLUSIONS: Our results suggest that the long-term memory outcome of TLE patients undergoing ATL without invasive presurgical assessment may be good in most cases not only for right-sided but also for left-sided resections.