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.     

Parkinson's disease motor subtypes and bilateral GPi deep brain stimulation: One-year outcomes

ObjectiveWe aimed to explore the differences in motor symptoms and quality of life (QOL) outcomes following bilateral globus pallidus internus deep brain stimulation (GPi DBS), across well-defined motor subtypes of Parkinson's disease (PD), to improve clinical decision making.MethodsThis single-center retrospective study investigated bilateral GPi DBS outcomes in 65 PD patients. Outcome measures included the Unified Parkinson's Disease Rating Scale (UPDRS) and Parkinson's Disease Questionnaire (PDQ-39) before and one year after surgery. Outcomes were compared between the tremor-dominant (TD) and postural instability and gait difficulty (PIGD) subtypes and between the TD and akinetic-rigid (AR) subtypes.ResultsFor the entire cohort, motor function (UPDRS III) in the Off-medication state, motor complications (UPDRS IV), activities of daily living (ADL, UPDRS II), and the ADL and discomfort domains of PDQ-39 significantly improved one year following GPi implantation compared to baseline (effect size = 1.32, 1.15, 0.25, 0.45, and 0.34, respectively). GPi DBS improved the Off-medication UPDRS III scores regardless of the motor subtypes. However, compared to the PIGD and AR patients, the TD patients showed greater improvement in overall UPDRS III postoperatively primarily due to greater tremor improvement in the Off-medication state. The outcomes in akinesia, rigidity, axial symptoms and QOL were similar among all subtypes.ConclusionBilateral GPi DBS was effective for advanced PD patients regardless of motor subtypes. Greater tremor improvement in the TD patients accounted for greater Off-medication motor improvement. Longer-term GPi DBS outcomes across different motor subtypes and brain targets should be further studied.     

Globus pallidus stimulation in advanced Parkinson's disease.

Deep brain stimulation (DBS) of the globus pallidus internus (GPi) has become an accepted therapeutic modality in selected Parkinson's disease (PD) patients with severe levodopa-induced dyskinesias (LID) and on-off motor fluctuations. In comparison to subthalamic nucleus DBS there is a paucity of data on GPi DBS outcomes. We present our experience with a group of 20 PD patients (9 unilateral, 11 bilateral) who underwent GPi stimulation. PD motor symptoms were assessed using the Unified Parkinson's Disease Rating Scale (UPDRS) part III scores and subscores, and dyskinesia using the Abnormal Involuntary Movement Scale (AIMS), UPDRS part IVa, and clinical global impression (CGI). At mean follow-up time of 7 months, bilateral stimulation reduced off-period motor scores by a mean of 46% and on-period motor scores by 18%. Unilateral stimulation reduced off-period motor scores by 18%. Dyskinesia severity was reduced by 76%, which was maintained after a mean follow-up time of 35 months. Antiparkinsonian medication dosage was unchanged. No major adverse effects were seen. Unilateral and bilateral GPi DBS provides lasting benefit in PD patients with severe LID. Beneficial effects on off-period motor symptoms are greater with bilateral stimulation; however, with maintenance of dopaminergic medication, unilateral procedures can also provide important and sustained benefits.     

Subthalamic deep brain stimulation in patients with a previous pallidotomy.

The safety and efficacy of subthalamic nucleus (STN) deep brain stimulation (DBS) in patients who have had a previous unilateral pallidotomy is not clear. We identified 10 patients (9 male) at the Baylor College of Medicine Parkinson's Disease Center who underwent STN DBS after prior unilateral pallidotomy. Demographics, efficacy as determined by off Unified Parkinson's Disease Rating Scale (UPDRS) part III scores, and levodopa equivalent dosing were analyzed. We then compared these to an age- and sex-matched group of 25 DBS patients who had no prior pallidotomy. After their initial pallidotomy (mean age, 51.8 +/- 10.8 years), the mean UPDRS motor off medicine scores improved from 51.3 +/- 14.3 to 34.9 +/- 12.8, and the UPDRS dyskinesia score improved from 1.8 +/- 1.0 to 0.8 +/- 0.7. Their STN DBS off UPDRS motor scores (mean age, 56.0 +/- 10.2 years) improved by 16.0% from 53.1 +/- 9.7 (range, 42-68) to 44.6 +/- 11.1 (range, 25-67). In contrast, the UPDRS off motor scores in a control group of 25 DBS patients improved by 49.9%, from 49.7 +/- 11.1 to 25.7 +/- 18.9, (16.0% vs. 49.9%; P < 0.001). Changes in UPDRS dyskinesia scores were similar in both groups. AE thought to be related to the STN DBS following pallidotomy included worse dysarthria (three) and worse balance (two). STN DBS patients with prior pallidotomy had less improvement in UPDRS off motor score compared to other STN DBS patients, despite relatively good outcomes immediately after their pallidotomy. This may be partially due to a selection bias, but it may also indicate that prior pallidotomy is a negative predictor of outcome of STN DBS and should be considered in patient selection.     

Does the ADL part of the unified Parkinson's disease rating scale measure ADL? An evaluation in patients after pallidotomy and thalamic deep brain stimulation

We evaluated the impact of pallidotomy and thalamic deep brain stimulation (DBS) on disability of patients with advanced Parkinson's disease and investigated whether the activities of daily living (ADL) section of the Unified Parkinson's Disease Rating Scale (UPDRS) measures disability in everyday life. Nineteen patients who had pallidotomy and 14 patients who had thalamic DBS were followed for a mean of 11 months. Evaluation tools included the UPDRS as well as a generic ADL scale, called ADL taxonomy. The 13 items belonging to the ADL part of the UPDRS were classified into two categories according to whether the items described a disability or impairment. The total scores of the UPDRS Part II (ADL) were ameliorated in both the pallidotomy and the thalamic DBS groups. When analysing separately the scores from the two categories of the ADL part of the UPDRS, i.e., disability and impairment, only patients who underwent pallidotomy showed improvement in disability-related items. These findings were confirmed when evaluating the patients with the ADL taxonomy. The ADL part of the UPDRS contains a mixture of impairment- and disability-related items. This mixture may confound results when evaluating the impact of surgery on ADL.     

Minimal clinically important change on the unified Parkinson's disease rating scale.

The Unified Parkinson's Disease Rating Scale (UPDRS) is the main outcome measure in clinical trials of Parkinson's disease (PD). The minimal change that represents a clinically meaningful improvement is unknown. The objective of this study was to determine the minimal change on the UPDRS that represents a clinically meaningful improvement in early PD after 6 months of treatment. Data from two independent randomized treatment trials over 6 months involving 603 patients with de novo PD were analyzed to determine the minimal clinically important change (MCIC), referred to the status before treatment, for the UPDRS motor, activities of daily living (ADL), and total scores. An anchor-based method using ratings on a seven-point global clinical improvement was used. A change of five points on the UPDRS motor part was found to be the most appropriate cutoff score for all Hoehn and Yahr stages I to III, and a change of eight points for the UDPRS total score. For the UDPRS ADL score, an MCIC of two points for Hoehn and Yahr stages I/I.5 and II and of three points for Hoehn and Yahr stage II.5/III was the most appropriate cutoff score. These data give the first estimate for cutoffs defining clinically important changes in UPDRS ADL and motor scores. Further studies using larger databases from more diverse study populations are encouraged to better define and solidify the MCIC for the UPDRS.     

Randomized trial of pallidotomy versus medical therapy for Parkinson's disease

Thirty-six patients with Parkinson's disease (PD) were randomized to either medical therapy (N = 18) or unilateral GPi pallidotomy (N = 18). The primary outcome variable was the change in total Unified Parkinson's Disease Rating Scale (UPDRS) score at 6 months. Secondary outcome variables included subscores and individual parkinsonian symptoms as determined from the UPDRS. At the six month follow-up, patients receiving pallidotomy had a statistically significant reduction (32% decrease) in the total UPDRS score compared to those randomized to medical therapy (5% increase). Following surgery, patients' showed improvement in all the cardinal motor signs of PD including tremor, rigidity, bradykinesia, gait and balance. Drug-induced dyskinesias were also markedly improved. Although the greatest improvement occurred on the side contralateral to the lesion, significant ipsilateral improvement was also observed for bradykinesia, rigidity and drug-induced dyskinesias. A total of twenty patients have been followed for 2 years to assess the effect of time on clinical outcome. These patients have shown sustained improvement in the total UPDRS (p < 0.0001), "off" motor (p < 0.0001) and complications of therapy subscores (p < 0.0001). Sustained improvement was also seen for tremor, rigidity, bradykinesia, percent on time and drug-induced dyskinesias.     

Weight gain following unilateral pallidotomy in Parkinson's disease

OBJECTIVE: To determine the clinical correlates and infer pathogenesis of weight gain following pallidotomy in patients with Parkinson's disease (PD). BACKGROUND: Surgical ablation of the globus pallidus internus (GPi) improves levodopa induced dyskinesias, moderately improves most other "cardinal" manifestations of PD, and has been noted to result in increased weight. METHODS: We incorporated Unified Parkinson's Disease Rating Scales (UPDRS) subscales, the Beck depression inventory and feeding questionnaire data into a linear regression model in order to determine which post-surgical change(s) may lead to weight gain over the first year following pallidotomy, n = 60. RESULTS: The mean weight gain 1 year after pallidotomy was 4.0 +/- 4.1 kg. Improvement in "off" motor scores (P < 0.005), especially gait subscores (P<0.0001), and to a lesser extent improvement in "on" motor scores (P<0.05) predicted weight gain. Changes in dyskinesia ratings, mood, food intake, dysphagia, levodopa dose, weight loss in the year prior to pallidotomy, age, and duration of PD did not correlate with subsequent weight gain. CONCLUSION: The high correlation between post-pallidotomy weight gain and "off" motor scores, suggests that this phenomenon is related to some change in underlying homeostasis associated with changes in the cardinal manifestations of PD itself, rather than secondary changes resultant from the surgery.     

Unilateral pallidotomy in advanced Parkinson's disease: a retrospective study of 26 patients.

OBJECTIVE: To evaluate the effects of unilateral pallidotomy in patients with Parkinson's disease (PD). PATIENTS AND METHODS: Twenty-six patients with PD and disabling dyskinesias, painful and/or disabling dystonia, and/or pain as part of PD despite optimal pharmacotherapy underwent unilateral pallidotomy. For assessment, the Unified Parkinson's Disease Rating Scale (UPDRS; part II and III), Hoehn and Yahr staging, the Schwab and England scale, a Dyskinesia Rating Scale, and timed tests were used. Assessment was performed in defined "off' and "on," and on average 2 months before and 7.5 months after the unilateral pallidotomy. Adverse effects were classified as transient or permanent and as major or minor. RESULTS: In the "off' phase, the median UPDRS II score improved from 26.5 to 20.5 (23%) and the median UPDRS III score improved from 47.5 to 33.0 (31%). In the "on" phase, dyskinesias contralateral to the side of the procedure improved with 88% ipsilateral dyskinesias improved only temporarily, and the total UPDRS II and III scores remained unchanged. Thirteen patients had transient adverse effects, three patients had permanent, and two patients had a combination of transient and permanent adverse effects. The transient adverse effects in two patients were classified as major. CONCLUSION: Stereotactic unilateral pallidotomy can improve symptoms and disability in the "off' phase. In the "on" phase, dyskinesias disappeared at the side contralateral to the procedure. Permanent minor complications of pallidotomy occurred in 19% of the patients.     

帕金森病患者非运动症状的发生及对日常生活能力的影响

目的 研究帕金森病(PD)患者非运动症状(NMS)的发生情况,及其对PD患者日常生活能力(ADL)的影响.方法 对107例PD患者进行NMS问卷(NMS Quest)调查,分析NMS的分布状况及临床特征,并采用统一PD评定量表(UPDRS)、Hoehn-Yahr分期、左旋多巴等效剂量、ADL问卷、MMSE评分进行评估,采用多元逐步线性回归探讨NMS对ADL的影响.结果 97.2%(104/107)的PD患者伴发不同程度的NMS,其发生数平均(8±5)个,其中尿频、便秘、记忆力下降最常见,发生率均超过50%;UPDRS-Ⅲ评分(28.0±16.4)分,能解释ADL总分变化的48.1%(R~2=0.481,P=0.000),引入NMS分值后,ADL分值可被解释的部分增加到51.1%.结论 PD患者普遍伴发NMS,而影响患者的ADL.PD可能是由NMS和运动症状共同组成的多系统神经变性疾病.PD患者的NMS在临床上应引起同样的重视,运动症状与NMS同治,才能提高疗效和ADL.     

Effect of pallidotomy on postural control and motor function in Parkinson disease.

OBJECTIVE: To investigate the effects of pallidotomy on postural reactions and other motor parkinsonian deficits. DESIGN: Comparison of performance by patients before and after pallidotomy on tests of balance and function. SETTING: A Parkinson disease Center of Excellence and Center for Human Performance Testing at a university hospital and research center. PARTICIPANTS: Twenty-nine patients with Parkinson disease undergoing pallidotomy. MAIN OUTCOME MEASURES: Performance results on the United Parkinson's Disease Rating Scale (UPDRS), activities of daily living and motor subscales (parts II and III). and posturography (sensory organization test), which were collected before and 3 and 6 months after surgery with patients in the practically defined off state (medication withheld for at least 12 hours). RESULTS: Data were analyzed with a paired Wilcoxon and Spearman correlation. There was a significant improvement in mean +/- SD UPDRS motor subscale score after pallidotomy (before surgery, 52.43+/-13.46; after surgery, 43.93+/-15.15; z= 3.63; P=.003). There were no significant changes in the UPDRS activities of daily living subscale or average stability scores when the group was examined as a whole. However, examination of individual data revealed that 9 (56%) of 16 patients who could stand independently before surgery showed improvement in either the number of falls or the average stability score. No patient who was unable to stand independently before surgery was able to stand independently after it. CONCLUSION: Pallidotomy helped improve overall motor function in patients with parkinsonism and, for some patients, also improved postural stability.     

Unilateral and bilateral pallidotomy for idiopathic Parkinson's disease: a case series of 115 patients.

Lesioning of the internal pallidum is known to improve the symptoms of idiopathic Parkinson's disease (PD) and alleviate dyskinesia and motor fluctuations related to levodopa therapy. The benefit obtained contralateral to a single lesion is insufficient in some cases when symptoms are bilaterally disabling. However, reports of unacceptably high rates of adverse effects after bilateral pallidotomy have limited its use in such cases. We report on the outcome of unilateral (UPVP) and bilateral (BPVP) posteroventral pallidotomy in a consecutive case series of 115 patients with PD in the United Kingdom and Australia. After 3 months, UPVP resulted in a 27% reduction in the off medication Part III (motor) Unified Parkinson's Disease Rating Scale score and abolition of dyskinesia in 40% of cases. For BPVP, these figures were increased to 31% and 63%, respectively. Follow-up of a smaller group to 12 months found the motor scores to be worsening but benefit to dyskinesia and activities of daily living was maintained. Speech was adversely affected after BPVP, although the change was small in most cases. Unilateral and bilateral pallidotomy can be performed safely without microelectrode localisation. Bilateral pallidotomy appears to be more effective, particularly in reducing dyskinesia; in our experience, the side effects have not been as high as reported by other groups.     

Test-retest reliability of the unified Parkinson's disease rating scale in patients with early Parkinson's disease: results from a multicenter clinical trial.

Our objective was to assess the test-retest reliability of the Unified Parkinson's Disease Rating Scale (UPDRS). The UPDRS is the most widely used instrument for measuring severity of parkinsonian symptoms in clinical research and in practice. The validity and inter-rater reliability of this scale have been previously studied. We examined the test-retest (intrarater) reliability of the UPDRS and derived subscales. Four hundred patients with early-stage Parkinson's disease (PD) who were participating in a multicenter clinical trial were evaluated using the UPDRS on two separate occasions (screening and baseline visits) prior to receiving treatment. The same neurologist at each center rated the subjects at both examinations that were, on average, 14.6 +/- 7.6 days apart (range 3-36 days). Test-retest reliability was estimated using the intraclass correlation coefficient (ICC) for the total UPDRS score, the mental, ADL, and motor subscale scores, and other derived subscale scores. Weighted kappa statistics were calculated for individual UPDRS items. The ICCs for the UPDRS scores were as follows: total score, 0.92; mental, 0.74; ADL, 0.85; motor, 0.90. ICCs for derived symptom-based scales ranged from 0.69-0.88. Reliability of specific items was generally lower than for summary scales. Reliability was slightly better in patients for whom the testing interval was within 14 days. Based on conventional standards, the UPDRS scores were found to have excellent test-retest reliability in this sample of patients with early PD rated by academic movement disorder specialists. The findings are in agreement with previous reports on interrater reliability.     

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。     

Efficacy and safety of simultaneous bilateral pallidotomy in advanced Parkinson's disease

BACKGROUND: Although unilateral pallidotomy is generally considered a safe and effective neurosurgical treatment for advanced Parkinson's disease (PD), controversies concerning efficacy and adverse effects of bilateral posteroventral pallidotomy (PVP) exist and need to be resolved. METHODS: We studied 8 patients with advanced PD who underwent simultaneous bilateral PVP. The patients were assessed preoperatively, immediately after surgery, and 6 and 12 months later. RESULTS: Dyskinesia was almost entirely abolished immediately after surgery, as well as being significantly lower 1 year later (p < 0.05). The 'off' medication score of the Unified Parkinson's Disease Rating Scale motor part (UPDRS III) was significantly improved after surgery (p < 0.05) but increased gradually after 6 months. The off medication score of activities of daily living tended to improve immediately after surgery, but it returned to preoperative levels at 12 months. There were no major complications of surgery. CONCLUSIONS: Simultaneous bilateral PVP may be a safe and highly effective method of reducing levodopa-induced dyskinesia. Our results suggest that simultaneous bilateral PVP may be a reasonable therapeutic option for advanced PD with severe levodopa-induced dyskinesia.     

Effects of pallidotomy and levodopa on walking and reaching movements in Parkinson's disease.

We examined the effects of levodopa and unilateral pallidotomy on quantitative measures of walking and reaching in Parkinson's disease (PD). We also compared quantitative measures of movement with standard clinical rating scales. We used kinematic measures and the Unified Parkinson's Disease Rating Scale (UPDRS) motor subscale (subscale III) to evaluate the movement of 10 people with PD. Subjects were tested after withholding PD medications for at least 8 hours and again 30 to 45 minutes after taking the first morning dose of levodopa. They were studied in this manner before unilateral pallidotomy and then 3.5 to 10 months after surgery. The UPDRS motor subscale was performed in each state. Kinematic data were collected as subjects reached to a target and walked. The UPDRS motor subscale ratings were similar to those reported in the literature: pallidotomy improved the overall motor score and the contralateral bradykinesia + rigidity score, but not the gait + posture score. In contrast, kinematic measures demonstrated that levodopa and pallidotomy had different effects on walking and reaching speed. Both treatments improved walking speed, and the effect was additive. Levodopa improved reaching speed before pallidotomy but did not improve it as much after pallidotomy. Additionally, pallidotomy had inconsistent effects on reaching; some subjects were faster and others were slower. The subjects who initially reached more slowly improved after pallidotomy; the subjects who initially reached more normally (faster) worsened after pallidotomy. On the basis of our results, we speculate that basal ganglia output pathways that control walking and reaching may be distinct, such that bilateral projections to the pedunculopontine area influence walking, whereas ipsilateral thalamocortical projections influence reaching.     

帕金森病患者自主神经功能障碍评估

目的：评估帕金森病（PD）患者中自主神经功能障碍症状发生比例、各症状分布的差异，及其与PD临床特点之间的关系。方法：应用SCOPA-AUT量表、统一帕金森病评分量表（UPDRS）、日常生活能力量表（ADL）、Hamilton抑郁量表和简易智能量表（MMSE）对116例原发性PD患者进行评估。结果：SCOPA-AUT总分和消化系统（GI）症状、排尿（UR）症状、体温调节（TH）症状、性功能（SX）症状评分均高于对照组，差异有极显著统计学意义（P=0．0001）。SCOPA-AUT总分与UPDRS评分、Hamilton抑郁量表评分呈正相关（P〈0．001），与生活质量ADL评分呈负相关（P〈0．001）。结论：自主神经功能障碍在PD早期就会出现，并随着疾病进展而加重，影响患者的生活质量。     

Long‐term results of a multicenter study on subthalamic and pallidal stimulation in Parkinson's disease

We report the 5 to 6 year follow‐up of a multicenter study of bilateral subthalamic nucleus (STN) and globus pallidus internus (GPi) deep brain stimulation (DBS) in advanced Parkinson's disease (PD) patients. Thirty‐five STN patients and 16 GPi patients were assessed at 5 to 6 years after DBS surgery. Primary outcome measure was the stimulation effect on the motor Unified Parkinson's Disease Rating Scale (UPDRS) assessed with a prospective cross‐over double‐blind assessment without medications (stimulation was randomly switched on or off). Secondary outcomes were motor UPDRS changes with unblinded assessments in off‐ and on‐medication states with and without stimulation, activities of daily living (ADL), anti‐PD medications, and dyskinesias. In double‐blind assessment, both STN and GPi DBS were significantly effective in improving the motor UPDRS scores (STN, P < 0.0001, 45.4%; GPi, P = 0.008, 20.0%) compared with off‐stimulation, regardless of the sequence of stimulation. In open assessment, both STN‐ and GPi‐DBS significantly improved the off‐medication motor UPDRS when compared with before surgery (STN, P < 0.001, 50.5%; GPi, P = 0.002, 35.6%). Dyskinesias and ADL were significantly improved in both groups. Anti‐PD medications were significantly reduced only in the STN group. Adverse events were more frequent in the STN group. These results confirm the long‐term efficacy of STN and GPi DBS in advanced PD. Although the surgical targets were not randomized, there was a trend to a better outcome of motor signs in the STN‐DBS patients and fewer adverse events in the GPi‐DBS group. © 2010 Movement Disorder Society     

Long-term effects of bilateral subthalamic nucleus stimulation in advanced Parkinson disease: a four year follow-up study

In this study we aimed to investigate the effects of bilateral STN HFS in patients with advanced Parkinson disease (PD) at long-term, with a minimum follow-up of 4 years. Twenty patients (15 men, five women) were included, with a mean age of 60.9+/-8.1 years. Surgery was performed under local anesthesia. The target was defined on computerized tomography (CT). At 3 months, significant improvements were found on the total Unified Parkinson disease rating scale (UPDRS) III (motor) score, in the medication. off (from 42.3+/-9.3 to 19.5+/-6.4), as well as the medication on (from 18.6+/-12.1 to 10.1+/-5.9) phase. The UPDRS IVa (dyskinesias) and IVb (motor fluctuations) scores decreased significantly. At long-term follow-up, there were still significant improvements on the total UPDRS III motor score (from 42.3+/-9.3 to 24.2+/-13.2), as well as in all motor subscores, in the off phase, during stimulation. In the on phase, the only significant improvement was seen for rigidity. Complications included hypomania to mania in four patients. Our results indicate that HFS STN results in long-lasting improvement of the motor symptoms, ADL activities and functional performance in patients suffering from advanced PD. The stimulation induced behavioural changes need special consideration.     

Subthalamic nucleus stimulation in advanced Parkinson's disease: blinded assessments at one year follow up

OBJECTIVE: To measure the effect of deep brain stimulation (DBS) of the subthalamic nucleus in patients with advanced Parkinson's disease. DESIGN: Open label follow up using blinded ratings of videotaped neurological examinations. PATIENTS: 30 patients with advanced Parkinson's disease (19 male, 11 female; mean age 58.8 years; mean disease duration 12.8 years), complicated by intractable wearing off motor fluctuations and dopaminergic dyskinesias. MAIN OUTCOME MEASURES: Unified Parkinson's disease rating scale (UPDRS), part III (motor), score at one year, from blinded reviews of videotaped neurological examinations. Secondary outcomes included the other UPDRS subscales, Hoehn and Yahr scale, activities of daily living (ADL) scale, mini-mental state examination (MMSE), estimates of motor fluctuations and dyskinesia severity, drug intake, and patient satisfaction questionnaire. RESULTS: Subthalamic nucleus stimulation was associated with a 29.5% reduction in motor scores at one year (p<0.0001). The only important predictors of improvement in UPDRS part III motor scores were the baseline response to dopaminergic drugs (p = 0.015) and the presence of tremor (p = 0.027). Hoehn and Yahr scores and ADL scores in the "on" and "off" states did not change, nor did the mean MMSE score. Weight gain occurred in the year after surgery, from (mean) 75.8 kg to 78.5 kg (p = 0.028). Duration of daily wearing off episodes was reduced by 69%. Dyskinesia severity was reduced by 60%. Drug requirements (in levodopa equivalents) declined by 30%. CONCLUSIONS: The 30% improvement in UPDRS motor scores was a more modest result than previously reported. DBS did not improve functional capacity independent of drug use. Its chief benefits were reduction in wearing off duration and dyskinesia severity.