Unilateral pallidotomy for Parkinson's disease: results after more than 1 year

Hemiballistic movements in a newly HIV patient

Infections of central nervous system (CNS) include a broad group of conditions and pose a particular challenge to physicians, especially in immunocompromised individuals.

This case refers to a 26-year-old male patient with a history of smoked hashish and drug abuse admitted to the infectious disease department with hemiballismus of left hemibody and a positive HIV serologic test. A magnetic resonance imaging (MRI) study showed lesions at lower left and right cerebellar hemisphere, one of them thalamus – mesencephalic suggesting an opportunistic infection or an HIV associated encephalopathy. Lumbar puncture, brain biopsy and successive neuroimaging were not conclusive for one disease and despite the use of directed therapy for cerebral toxoplasmosis, meningeal tuberculosis, anti-retrovirals and sedative medication, after over 6 weeks of hospitalization pallidotomy was performed. After 5 months of oral and surgical treatment the patient showed clinical, immunological and radiological recovery.

Surgical approaches to treatment of Parkinson's disease: Implications for speech function

Although neurosurgical procedures have been reported to be successful in relieving many of the motor symptoms of Parkinson's disease (PD) (e.g., tremor, rigidity, bradykinesia) in the limb musculature, their effect on speech is much less consistent. This paper will review and evaluate reports in the literature on the effects of various surgical interventions for PD, including thalamotomy, pallidotomy, and DBS, on speech. In particular the paper will focus on the implications of these findings for one's understanding of the neurological control of the speech mechanism. As a foundation, contemporary models of the neuropathophysiology of PD and hypokinetic dysarthria will be outlined and explained. The various neurosurgical treatments for PD will be described and their theoretical underpinning discussed with regard to their proposed effects on subcortical and cortical motor control systems. Evidence suggestive of the need to reconsider contemporary thinking in relation to the neurology of speech and the need to differentiate it from limb neurology will be highlighted.

Functional surgery for Parkinson's disease treatment: a structured analysis of a decade of published literature

The aim of this study was to analyse and compare published data during the last decade on the different approaches to Parkinson's disease surgery. Eighty-eight papers published between 1990 and 2001 fulfilled the inclusion criteria. Full-text and prospective papers on lesion and stimulation of GPi or STN were assessed. Descriptive analysis of surgery procedure and population under study was performed, as well as a meta-analysis of the most consistently reported variables. A total of 1702 patients underwent surgery with a mean age of 58.75 years (range 46.5 - 72.5), mean duration of illness 13.6 years (8.1 - 18.1) and a male:female ratio 1.5:1. Mean postoperative follow-up was 9 months (1 - 52). Single blind assessment was performed in two papers, while double blind evaluation was used in 6. In the GPi group, no difference was found between the pre- and postoperative levodopa equivalent daily dose (960.39 v. 943.13; p > 0.05), while the STN group showed a marked reduction (1104.8 v. 483.04; p < 0.05) of this dosage. Meta-analysis of the most consistently reported variables (UPDRS total score, UPDRS motor score, UPDRS ADL score and Schwab & England score showed that Nucleus, Bilaterality of Approach and Surgical Procedure were the best moderators for defining outcome. Bilateral DBS STN procedures proved to be associated with better outcome. Microelectrode recording was not found to be a moderator that influenced outcome. Although there was a significant improvement of dyskinesias among the different approaches described in the papers, the heterogeneity of data makes it impossible to perform a structured analysis on this item.

Comparative Evaluation of the Effects of Unilateral Lesion versus Electrical Stimulation of the Globus Pallidus Internus in Advanced Parkinson’s Disease

OBJECTIVE

To perform a prospective analysis on the effects of unilateral lesion versus unilateral electrical stimulation (ES) of the globus pallidus internus (Gpi) in the treatment of bilateral Parkinson's disease (PD).

MATERIALS AND METHODS

We studied 18 patients with stages III-V on the Hoehn and Yahr (H-Y) scale having prominent rigidity, bradykinesia and gait disturbances. Nine patients were treated with lesions and 9 patients with ES. Both groups were evaluated using the New York Parkinson's Disease Scale, the Unified Parkinson's Disease Rating Scale part III, and the H-Y scale and with specific items of tremor, rigidity and bradykinesia independently on each side. Both lesions and electrodes for ES were placed stereotactically in the Gpi as confirmed by postoperative magnetic resonance images. Significance of changes was evaluated with the Wilcoxon test after 3 and 6 months. Significance of intergroup differences was evaluated using the Mann-Whitney U test.

RESULTS

Lesions and ES significantly decreased rigidity (p < 0.01) and bradykinesia (p < 0.005) in the contralateral extremities. ES significantly decreased tremor in the contralateral extremities (p < 0.01) and rigidity and bradykinesia ipsilaterally (p < 0.01) at 3 months. There were no significant intergroup differences. The H-Y scale score showed improvement in self-sufficiency. L-DOPA dose was decreased by 31%.

CONCLUSIONS

ES was a safer procedure and more efficient in controlling PD symptoms. Unilateral lesions and ES may improve bilateral symptoms to the point of making patients self-sufficient.

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.

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.

A metaanalysis comparing the results of pallidotomy performed using microelectrode recording or macroelectrode stimulation

OBJECT

There is an active debate regarding whether pallidotomy should be performed using macroelectrode stimulation or the more sophisticated and expensive method of microelectrode recording. No prospective, randomized trial results have answered this question, although personnel at many centers claim one method is superior. In their metaanalysis the authors reviewed published reports of both methods to determine if there is a significant difference in clinical outcomes or complication rates associated with these methods.

METHODS

A metaanalysis was performed with data from reports on the use of unilateral pallidotomy in patients with Parkinson disease (PD) that were published between 1992 and 2000. A Medline search was conducted for the key word "pallidotomy" and additional studies were added following a review of the references. Only those studies dealing with unilateral procedures performed in patients with PD were included. Papers were excluded if they described a cohort smaller than 10 patients or a follow-up period shorter than 3 months or included cases that previously had been reported. The primary end points for outcome were the percentages of improvement in dyskinesias and in motor scores determined by the Unified PD Rating Scale (UPDRS). Complications were categorized as mortality, intracranial hemorrhage, visual deficit, speech deficit, cognitive decline, weakness, and other. There were no significant differences between the two methods with respect to improvements in dyskinesias (p = 0.66) or UPDRS motor scores (p = 0.62). Microelectrode recording was associated with a significantly higher (p = 0.012) intracranial hemorrhage rate (1.3 +/- 0.4%), compared with macroelectrode stimulation (0.25 +/- 0.2%).

CONCLUSIONS

In reports of patients with PD who underwent unilateral pallidotomy, operations that included microelectrode recording were associated with a small, but significantly higher rate of symptomatic intracranial hemorrhage; however, there was no difference in postoperative reduction of dyskinesia or bradykinesia compared with operations that included macroelectrode stimulation.

Ropinirole for the treatment of tremor in early Parkinson's disease

The effect of Ropinirole on tremor in early Parkinson's disease (PD) was assessed. The results of three multicentre, randomized, double-blind trials comparing ropinirole monotherapy with levodopa, bromocriptine and placebo treatment were analysed retrospectively with respect to improvement of resting tremor and postural/action tremor as measured by items 20 and 21 of the motor section of the Unified Parkinson's Disease Rating Scale (UPDRS). Improvements in resting tremor were significantly better with ropinirole than placebo. There were no significant differences between the effect of ropinirole and those of levodopa (L-dopa) or bromocriptine on resting tremor. Postural/action tremor was mild in these early therapy studies, and there were no significant differences between treatment groups. These results suggest that ropinirole monotherapy is effective in treating resting tremor in early PD. On the other hand, response of postural/action tremor to dopaminergic treatment in early PD was not significantly better than to placebo at the dosages used in these trials.

Outcome of unilateral pallidotomy in advanced Parkinson's disease: cohort study of 32 patients

OBJECTIVES

In a randomised trial to study the efficacy of unilateral pallidotomy in patients with advanced Parkinson's disease, patients having pallidotomy within 1 month after randomisation were compared with patients having pallidotomy 6 months after the primary outcome assessment. Of the 37 patients enrolled 32 had a unilateral pallidotomy. The follow up study of these patients is presented to report (1) clinical outcome; (2) adverse effects; (3) cognitive and behavioural effects; (4) relation between lesion location and outcome; and (5) preoperative patient characteristics predictive for good outcome.

METHODS

Outcome measures were the motor section of the unified Parkinson's disease rating scale (UPDRS), levodopa induced dyskinesias, disability, quality of life, and a comprehensive neuropsychological assessment. Multivariate logistic regression was used to identify preoperative patient characteristics independently associated with good outcome.

RESULTS

Off phase assessment showed a reduction in parkinsonism from 49 to 36.5 points on the UPDRS 6 months after surgery. Improvements were also demonstrated for activities of daily living and quality of life. In the on phase dyskinesias were reduced. All effects lasted up to 12 months after surgery. Three patients had major permanent adverse effects. Besides worsening of verbal fluency after left sided surgery, systematic cognitive deterioration was not detected. Patients taking less than 1000 levodopa equivalent units (LEU)/day were more likely to improve.

CONCLUSIONS

The positive effects of unilateral pallidotomy are stable up to 1 year after surgery. Patients taking less than 1000 LEU per day were most likely to improve.

Updated guidelines for the management of Parkinson's disease

New data on diagnosis, drug therapy, surgery and psychosocial concerns have emerged since the publication of the 1998 Guidelines for the Management of Parkinson's Disease. This article reviews new data and addresses issues left unanswered in the previous guidelines.

Parkinson's disease: surgical options

The introduction of levodopa revolutionized the treatment of Parkinson's disease. However, complications of therapy that diminish functional capacity eventually develop in the majority of patients. Studies in animal models have demonstrated that the parkinsonian state is associated with overactivity in the output nuclei of the basal ganglia. This provides a rationale for surgically targeting these nuclei to diminish this overactivity and reestablish a more balanced output (compensatory strategy). Lesioning and high-frequency stimulation of either the pallidum or the subthalamic nuclei are effective, but many questions remain regarding what surgery is best. Even more questions remain regarding the place of a restorative strategy, namely implantation of fetal midbrain tissue to replace the missing dopamine cells and "cure" the disease. Practical, ethical, and legal issues that complicate the use of human tissue have encouraged initial attempts at xenotransplantation using porcine fetal tissue.

Clinicoanatomic studies in dysarthria: review, critique, and directions for research

More than 30 years ago, Darley, Aronson, and Brown (1969) proposed clinicoanatomic correlations for seven perceptual types of dysarthria. These correlations have not been systematically re-examined even though imaging technologies developed in recent years provide the means to do so. This review considers data from published imaging studies as well as data from selected medical interventions to evaluate the current state of knowledge that relates lesion site to the nature of a speech disturbance. Although the extant data are not sufficient to allow a complete evaluation of the seven types of dysarthria described by Darley et al., relevant information has been reported on lesions of the pyramidal pathway, extrapyramidal pathway, and cerebellum. In general, the results are best explained by an equivalence mode of brain-behavior relationship in which a type of dysarthria is associated with a lesion in one of two or more brain structures. Criteria also are proposed for future studies of clinicoanatomic relationships in neurogenic communication disorders.

Research on speech motor control and its disorders: a review and prospective

This paper reviews issues in speech motor control and a class of communication disorders known as motor speech disorders. Speech motor control refers to the systems and strategies that regulate the production of speech, including the planning and preparation of movements (sometimes called motor programming) and the execution of movement plans to result in muscle contractions and structural displacements. Traditionally, speech motor control is distinguished from phonologic operations, but in some recent phonologic theories, there is a deliberate blurring of the boundaries between phonologic representation and motor functions. Moreover, there is continuing discussion in the literature as to whether a given motor speech disorder (especially apraxia of speech and stuttering) should be understood at the phonologic level, the motoric level, or both of these. The motor speech disorders considered here include: the dysarthrias, apraxia of speech, developmental apraxia of speech, developmental stuttering, acquired (neurogenic and psychogenic) stuttering, and cluttering.