Life events and the onset of motor symptoms in Parkinson's disease

BACKGROUND

Whether there may be any relationship between stressful or traumatic life events (LE) and the subsequent motor symptoms onset in Parkinson's disease (PD) is still controversial.

OBJECTIVES

To explore whether a subjectively perceived as stressful or traumatic LE were more frequently present in a group of recent motor onset parkinsonian patients (Recent Onset Parkinsonism - ROP) compared with healthy controls (HC) and a group of patients already diagnosed as PD.

METHODS

A consecutive series of 139 ROP patients, 138 matched PD patients and 138 HC were pooled through a validated LE exposure questionnaire evaluating the number of patients affected by LE and the amount of LE per group occurred in the last year, segregating by subjective severity in total and severe LE.

RESULTS

There was no significant difference in the percentage of patients affected by total (p = 0.134) nor by severe (p = 0.133) LE within the 3 groups. No significant difference was observed in the number of total LE between ROP and HC (p = 0.063), ROP and PD (p = 0.688), nor in severe LE (ROP vs. HC, p = 0.637. ROP vs. PD, p = 0.500).

CONCLUSIONS

During the year of parkinsonian motor symptoms onset, the number of ROP patients exposed to total or severe LE or the amount of total or severe LE suffered by ROP were not significantly different to the group of PD patients or HC. A casual relationship between LE and the onset of motor symptoms in parkinsonian patients may be suggested.

P145 A DUAL CARDIAC COMPLICATION FOR … COMBINATION CHEMOTHERAPY FOR KIDNEY CANCER

We present the case of a 66–year–old patient suffering from metastatic kidney cancer who came to the emergency room complaining of dyspnea. 10 days prior to the event, the patient had received the last administration of chemotherapy which consisted of the combination of pembrolizumab (a monoclonal antibody) and axitinib (a tyrosine kinase inhibitor). The cardiological checks carried out up to that moment had not shown changes in the heart. In the emergency room ECG showed the presence of a sinus rhythm with a complete block of the right branch and no signs of ischemia were evident; blood chemistry tests showed an increase in troponin and BNP values. Echocardiography showed moderate left ventricular dysfunction. Therapy with diuretics, beta–blockers and Ras inhibitors was initiated which allowed for rapid resolution of symptoms. At a follow–up five days later the patient presented asymptomatic but with diffuse inversion of the T waves, a new elevation of troponin and more surprisingly the echo showed, in the presence of moderate left ventricular dysfunction, a mobile formation at the level of the apex of the left ventricle. Unfractionated heparin therapy was initiated since, on the basis of echocardiographic characteristics, the diagnosis appeared to be that of thrombosis and chemotherapy was suspended. In the following days the echo did not reveal any modification of the neoformation therefore in consideration of the characteristics (size and high degree of mobility) and of the oncological prognosis of more than one year we decided to initiate the patient to cardiac surgery for the removal operation. The histological analysis of the neoformation confirmed the thrombotic nature. Repeated echocardiography 15 days after surgery showed an almost complete recovery of the ejection fraction. To our knowledge, tyrosine kinase inhibitors can cause ventricular dysfunction (apoptosis) but, in general, it is not an acute event. Pembrolizumab has caused cases of acute myocarditis requiring discontinuation of therapy. As for the origin of the thrombosis the causes are not clear, it could be an effect of left ventricular dysfunction for myocarditis but it cannot be excluded that it is secondary to the use of one or both chemotherapy drugs.

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Validation of an events exposure questionnaire for individuals living in major cities of Argentina

Most of the validated 'events exposure' questionnaires are focused on lifetime burden and are hardly applicable to Argentina owing to its sociocultural and natural conditions, where corruption and economic crises have been hitting middle-class people's lives in a cyclic manner. This prompted us to develop a new questionnaire, validated in Argentina, to assess the occurrence of exposure to events and their severity over a limited period. Deductive (bibliographic search) and inductive (by a Delphi group) selection was used to create an initial group of 24 questions, which were condensed into a final 14-item questionnaire. After administration to 512 inhabitants of the metropolitan area of Buenos Aires and other major cities in Argentina, the questionnaire was shown to have an intraclass correlation coefficient of 0.996 and an internal consistency, measured by the omega coefficient, of 0.86. Because this study was conducted during the coronavirus disease 2019 (COVID-19) pandemic, an additional question on how this situation affected individuals was included. The time span used to measure event exposure was 1 year prior to the study. In the case of an affirmative event exposure, the responder selected the severity of the stress perception generated on a Likert-like scale, ranging from 0 (nothing) to 5 (severe). Fifty-eight per cent of the responders were women, and the mean age was 47.14 years (SD: 13.97). The average annual event incidence per person was 2.5 events (SD: 1.88). Thirty-two per cent (164/512) reported at least one 5-point event on the severity scale. Ten per cent (51/512) responded that the COVID-19 pandemic affected them in a different manner than events related to personal or family disease, or the death of a close family member or friend.

Multiple-time-scale framework for understanding the progression of Parkinson's disease

Parkinson's disease is marked by neurodegenerative processes that affect the pattern of discharge of basal ganglia neurons. The main features observed in the parkinsonian globus pallidus pars interna (GPi), a subdomain of the basal ganglia that is involved in the regulation of voluntary movement, are pathologically increased and synchronized neuronal activity. How these changes affect the implemented neuronal code is not well understood. Our experimental temporal structure-function analysis shows that in parkinsonian animals the rate-coding window of GPi neurons needed for the proper performance of voluntary actions is reduced. The model of the GPi network that we develop and discuss here reveals indeed that the size of the rate-coding window shrinks as the network activity increases and is expanded if the coupling strength among the neurons is increased. This leads to the novel interpretation that the pathological neuronal synchronization in Parkinson's disease in the GPi is the result of a collective attempt to counterbalance the shrinking of the rate-coding window due to increased activity in GPi neurons.

Autosomal dominant cerebellar ataxias: a systematic review of clinical features

BACKGROUND AND PURPOSE

To assess, through systematic review, distinctive or common clinical signs of autosomal dominant cerebellar ataxias (ADCAs), also referred to as spinocerebellar ataxias (SCAs) in genetic nomenclature.

METHODS

This was a structured search of electronic databases up to September 2012 conducted by two independent reviewers. Publications containing proportions or descriptions of ADCA clinical features written in several languages were selected. Gray literature was included and a back-search was conducted of retrieved publication reference lists. Initial selection was based on title and abstract screening, followed by full-text reading of potentially relevant publications. Clinical findings and demographic data from genetically confirmed patients were extracted. Data were analyzed using the chi-squared test and controlled for alpha-error inflation by applying the Holms step-down procedure.

RESULTS

In all, 1062 publications reviewing 12 141 patients (52% male) from 30 SCAs were analyzed. Mean age at onset was 35 ± 11 years. Onset symptoms in 3945 patients revealed gait ataxia as the most frequent sign (68%), whereas overall non-ataxia symptom frequency was 50%. Some ADCAs often presented non-ataxia symptoms at onset, such as SCA7 (visual impairment), SCA14 (myoclonus) and SCA17 (parkinsonism). Therefore a categorization into two groups was established: pure ataxia and mainly non-ataxia forms. During overall disease course, dysarthria (90%) and saccadic eye movement alterations (69%) were the most prevalent non-ataxia findings. Some ADCAs were clinically restricted to cerebellar dysfunction, whilst others presented additional features.

CONCLUSIONS

Autosomal dominant cerebellar ataxias encompass a broad spectrum of clinical features with high prevalence of non-ataxia symptoms. Certain features distinguish different genetic subtypes. A new algorithm for ADCA classification at disease onset is proposed.

Prospective evaluation of parkinsonism and tremor in patients treated with valproate

We observed a high incidence of postural and intentional tremor in patients exposed to VPA, although not strong enough to interfere with normal life. l-dopa unresponsive parkinsonism was recorded in 10% of patients who received VPA treatment. No correlation with gender, dosage, duration of treatment or concomitant administration of other antiepileptic drugs was observed. The mechanisms for such side effects are unclear. As new GABA mimetic drugs have been postulated to be useful in tremor control [8], it remains paradoxical that VPA should exacerbate such symptomatology by means of a similar mechanism of action.

Decision-making in Parkinson's disease patients with and without pathological gambling

BACKGROUND AND PURPOSE

Pathological gambling (PG) in Parkinson's disease (PD) is a frequent impulse control disorder associated mainly with dopamine replacement therapy. As impairments in decision-making were described independently in PG and PD, the objective of this study was to assess decision-making processes in PD patients with and without PG.

METHODS

Seven PD patients with PG and 13 age, sex, education and disease severity matched PD patients without gambling behavior were enrolled in the study. All patients were assessed with a comprehensive neuropsychiatric and cognitive evaluation, including tasks used to assess decision-making abilities under ambiguous or risky situations, like the Iowa Gambling Task (IGT), the Game of Dice Task and the Investment Task.

RESULTS

Compared to PD patients without gambling behavior, those with PG obtained poorer scores in the IGT and in a rating scale of social behavior, but not in other decision-making and cognitive tasks.

CONCLUSIONS

Low performance in decision-making under ambiguity and abnormal social behavior distinguished PD patients with PG from those without this disorder. Dopamine replacement therapy may induce dysfunction of the ventromedial prefrontal cortex and amygdala-ventral striatum system, thus increasing the risk for developing PG.

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.

Addenbrooke's Cognitive Examination validation in Parkinson's disease

BACKGROUND

There is a clear need for brief, sensitive and specific cognitive screening instruments in Parkinson's disease (PD).

OBJECTIVES

To study Addenbrooke's Cognitive Examination (ACE) validity for cognitive assessment of PD patient's using the Mattis Dementia Rating Scale (MDRS) as reference method. A specific scale for cognitive evaluation in PD, in this instance the Scales for Outcomes of Parkinson's disease-Cognition (SCOPA-COG), as well as a general use scale the Mini-mental state examination (MMSE) were also studied for further correlation.

METHODS

Forty-four PD patients were studied, of these 27 were males (61%), with a mean (SD) age of 69.5 (11.8) years, mean (SD) disease duration of 7.6 (6.4) years (range 1-25), mean (SD) total Unified Parkinson's Disease Rating Scale (UPDRS) score 37 (24) points, UPDRS III 16.5 (11.3) points. MDRS, ACE and SCOPA-COG scales were administered in random order. All patients remained in on-state during the study.

RESULTS

Addenbrooke's Cognitive Examination correlated with SCOPA-COG (r = 0.93, P < 0.0001), and MDRS (r = 0.91 P < 0.0001) and also with MMSE (r = 0.84, P < 0.001). Area under the receiver-operating curve, taking MDRS as the reference test, was 0.97 [95% confidence interval (CI): 0.92-1.00] for ACE, 0.92 (95% CI: 0.83-1.00) for SCOPA-COG and 0.91 (95% CI: 0.83-1.00) for MMSE. Best cut-off value for ACE was 83 points [Sensitivity (Se) = 92%; Specificity (Sp) = 91%; Kappa concordance (K) = 0.79], 20 points for the SCOPA-COG (Se = 92%; Sp = 87%; K = 0.74) and 26 points for MMSE (Se = 61%; Sp = 100%; K = 0.69).

CONCLUSION

Addenbrooke's Cognitive Examination appears to be a valid tool for dementia evaluation in PD, with a cut-off point which should probably be set at 83 points, displaying good correlation with both the scale specifically designed for cognitive deficits in PD namely SCOPA-COG, as well as with less specific tests such as MMSE.

[Non-motor disorders in Parkinson's disease]

INTRODUCTION

Parkinson's disease (PD) is a progressive disorder that is strongly linked to non-motor symptoms (NMS). Unfortunately, these symptoms have been almost neglected for many years and only recently have researchers begun to assess how they affect the quality of life in patients with PD.

AIMS

To review our current understanding of the subject and to highlight the importance of NMS in PD.

DEVELOPMENT

Recent studies have emphasised the fact that the basal ganglia play an important role in a number of non-motor functions. At the same time, the exclusive involvement of the substantia nigra in PD is being reviewed and the development of PD has been defined as a continuum that covers a range of different stages, including non-dopaminergic systems and nuclei. This would account for the constellation of non-motor symptoms that do not respond to dopamine replacement therapy and which affect patients with PD, such as depression, apathy, sialorrhea and urinary incontinence, among others.

CONCLUSIONS

NMS make a significant contribution to the morbidity and mortality rates of PD and are often the main cause of hospitalisation of patients with PD. Current evidence suggests that some NMS, such as constipation, hyposmia and REM sleep disorders, could even be preclinical markers of PD. Both of these reasons stress the importance of reaching a diagnosis faster and earlier.

Kinematic evaluation of gestural and repetitive single joint movements of the arm after posteroventral pallidotomy, subthalamotomy or both procedures combined in two Parkinson's disease patients: two case studies

Two patients with severe Parkinson's disease undergoing partial or complete ablative interruption of basal ganglia (BG) output are presented. One patient who underwent bilateral subthalamotomy, and a second who underwent unilateral posteroventral pallidotomy, followed 7 years later by a bilateral subthalamotomy because of contralateral disease progression, were studied. In addition to the usual clinical evaluation, changes in joint kinematics observed during unconstrained, skilled multi-joint movement and repetitive single joint (RSJ) movement of the wrist were studied. Clinical UPDRS items referred to hand movements contralateral to the procedure, and instrumental measurement of RSJ improved in both patients after either pallidotomy or subthalamotomy. When both BG outflow paths were interrupted as was the case in the second patient (bilateral subthalamotomy after the initial pallidotomy), no added clinical improvement was observed, RSJ even deteriorated slightly. Instrument-based studies for movement alteration detection after simultaneous ablation of the globus pallidus and the subthalamic nucleus of these two patients showed greater sensitivity than clinical evaluation alone. Complex gestural movement performance remained unaffected after partial (subthalamotomy or pallidotomy) or complete interruption of BG outflow (case 2), indicating BG compensatory capacity after total outflow interruption remained intact.

Dyskinesias induced by subthalamotomy in Parkinson's disease are unresponsive to amantadine

BACKGROUND

Dyskinesias are a transient but severe complication of subthalamotomy in some patients.

PATIENTS AND METHODS

Three patients with Parkinson's disease undergoing bilateral micro-recording guided surgery of the subthalamic nucleus (STN) are described; deep brain stimulation (DBS) was used in one case, and subthalamotomy in the other two. Prior to surgery, levodopa induced dyskinesia had improved (< or = 50%) under treatment with amantadine (400 mg/day, po) in all three patients. The patient treated with DBS developed severe dyskinesia a few days after discharge and began self medication with amantadine but showed no improvement. This suggested a possible lack of response to amantadine for treatment of dyskinesias induced by surgery of the STN.

RESULTS

Both patients treated with bilateral subthalamotomy developed unilateral choreoballistic movements immediately after surgery, despite not taking levodopa (L-dopa). Patients were scored using the dyskinesia scale and started treatment with 400 mg amantadine (po) for 4 days within the first postoperative week with no effect on dyskinesia score or its phenomenology. Amantadine was therefore discontinued. One month after surgery both patients were free of involuntary movements with an improvement of about 60% in the "off" state UPDRS motor score. Six month follow up showed maintained antiparkinsonian benefit, without need for levodopa treatment and complete absence of dyskinesia.

CONCLUSION

The present findings suggest that: (i) amantadine probably exerts its anti-dyskinetic effect by acting on the "indirect" pathway; (ii) the pathophysiological mechanisms of subthalamotomy induced dyskinesias may differ from those involved in L-dopa induced dyskinesias; (iii) dyskinesias induced by STN surgery resolve spontaneously as compensatory mechanisms develop.

Bilateral pallidotomy for treatment of Parkinson's disease induced corticobulbar syndrome and psychic akinesia avoidable by globus pallidus lesion combined with contralateral stimulation

OBJECTIVE

Posteroventral pallidotomy (PVP) has proved to be an effective method for the treatment of Parkinson's disease. However, data on bilateral procedures are still limited. To assess the effects of bilateral globus pallidus (GPi) lesion and to compare it with a combination of unilateral GPi lesion plus contralateral GPi stimulation (PVP+PVS), an open blind randomised trial was designed.

METHODS

A prospective series of patients with severe Parkinson's disease refractory to medical treatment, and severe drug induced dyskinesias, were randomised either to simultaneous bilateral PVP or simultaneous PVP+PVS. All patients were assessed with the core assessment programme for intracerebral transplantation (CAPIT), and a comprehensive neuropsychological and neuropsychiatric battery both before surgery and 3 months later.

RESULTS

The severe adverse effects found in the first three patients subjected to bilateral PVP led to discontinuation of the protocol. All three patients developed depression and apathy. Speech, salivation, and swallowing, as well as freezing, walking, and falling, dramatically worsened. By contrast, all three patients undergoing PVP+PVS had a significant motor improvement.

CONCLUSION

Bilateral simultaneous lesions within the GPi may produce severe motor and psychiatric complications. On the other hand, a combination of PVP+ PVS significantly improves parkinsonian symptoms not associated with the side effects elicited by bilateral lesions.

Prevalence and correlates of parkinsonism in patients with primary depression

The authors examined the prevalence, clinical correlates, and longitudinal changes of parkinsonism in 94 patients with primary depression and 20 healthy control subjects. Parkinsonism was present in 20% of patients with primary depression. This syndrome was significantly associated with older age, more severe depression, and more severe cognitive impairment. In a subgroup of depressed patients, parkinsonism was reversible upon recovery from the mood disorder.

Mismatch between electrophysiologically defined and ventriculography based theoretical targets for posteroventral pallidotomy in Parkinson's disease

OBJECTIVES

Over the past few years many reports have shown that posteroventral pallidotomy is an effective method for treating advanced cases of Parkinson's disease. The main differences with earlier descriptions were the use of standardised evaluation with new high resolution MRI studies and of single cell microrecording which can electrophysiologically define the sensorimotor portion of the internal globus pallidus (GPi). The present study was performed on a consecutive series of 40 patients with Parkinson's disease who underwent posteroventral pallidotomy to determine localisation discrepancies between the ventriculography based theoretical and the electrophysiologically defined target for posteroventral pallidotomy.

METHODS

The tentative location of the posteroventral GPi portion was defined according to the proportional Talairach system. Single cell recording was performed in all patients. The definitive target was chosen according to the feasibility of recording single cells with GPi cell features, including the presence of motor drive and correct identification of the internal capsule and of the optic tract by activity recording and microstimulation.

RESULTS

In all 40 patients the electrophysiologically defined sensorimotor portion of the GPi was lesioned, with significantly improved cardinal Parkinson's disease symptoms as well as levodopa induced dyskinesias, without damage to the internal capsule or optic tract. Significant differences between the localisation of the ventriculography based theoretical versus electrophysiological target were found in depth (p<0.0008) and posteriority (p<0.04). No significant differences were found in laterality between both approaches. Difference ranges were 8 mm for laterality, 6.5 mm for depth, and 10 mm for posteriority.

CONCLUSIONS

Electrophysiologically defined lesion of GPi for posteroventral pallidotomy, shown to be effective for treating Parkinson's disease, is located at a significantly different site from the ventriculography based theoretical target.

Disruption of spatial organization and interjoint coordination in Parkinson's disease, progressive supranuclear palsy, and multiple system atrophy

Patients with basal ganglia diseases may exhibit ideomotor apraxia. To define the nature of the impairment of the action production system, we studied a repetitive gesture of slicing bread by three-dimensional computergraphic analysis in eight nondemented patients with Parkinson's disease in the "on" state, five with progressive supranuclear palsy and four with multiple system atrophy. Two patients with Parkinson's disease and two with progressive supranuclear palsy showed ideomotor apraxia for transitive movements on standard testing. A Selspott II system was used for kinematic analysis of wrist trajectories and angular motions of the shoulder and elbow joints. Patients with Parkinson's disease, progressive supranuclear palsy, and even some with multiple system atrophy exhibited kinematic deficits in the spatial precision of movement and velocity-curvature relationships; in addition, they failed to maintain proper angle/angle relationships and to apportion their relative joint amplitudes normally. Spatial disruption of wrist trajectories was more severe in patients with ideomotor apraxia. We posit that the basal ganglia are part of the parallel parieto-frontal circuits devoted to sensorimotor integration for object-oriented behavior. The severity and characteristics of spatial abnormalities of a transitive movement would therefore depend on the location and distribution of the pathologic process within these circuits.

[Functional anatomy of the basal ganglia]

INTRODUCTION

The cerebral cortex of mammals is massively interconnected with the basal ganglia. The manner in which the basal ganglia process information has been accepted since it was described in the 1980s. It is not a definitive model and many aspects of it still need clarification.

DEVELOPMENT

The corpus striatum (ST) forms the entrance to the basal ganglia circuit (BG) and receives numerous afferent fibres from the cerebral cortex. Similarly, the internal segment of the globus pallidus (GPi) and the substantia nigra pars reticulata (SNpr) form the main nuclei for exit from the circuit and have an inhibitory effect on the pre-motor neurones of the ventral lamina of the thalamus. Between the entrance nucleus and the exit structures are two parallel systems of projection known as the direct and indirect pathways. The direct pathway projects monosynaptically only on the Gpi/SNpr complex. The indirect pathway projects polysynaptically on to the GR/SNpr complex after passing through the external segment of the globus pallidus (Gpe) and subthalamic nucleus. Imbalance in the activity of these two circuits will lead to alterations in discharge from the Gpi/SNpr complex which will cause bradykinesia or hyperkinesia. The bradykinesia or akinesia would be caused by increased gabaergic inhibition of the thalamic premotor neurones as a result of excessive discharge of the Gpi/SNpr complex.

CONCLUSION

Current exploration of the electrophysiology of the basal ganglia and careful analysis of the clinical findings in lesions circumscribed to certain parts of the thalamus, subthalamus and internal globus pallidus in patients with Parkinson's disease, have led to the appearance of paradoxical effects, according to the current basal ganglia model.

Explicit and implicit learning in patients with Alzheimer disease and Parkinson disease with dementia

OBJECTIVE

To examine the differential impairment of implicit and explicit memory systems in cortical and subcortical dementias.

BACKGROUND

Whereas verbal priming was reported to be impaired in patients with Alzheimer Disease (AD), patients with Parkinson Disease (PD) may be relatively more impaired on tasks of motor skill learning.

METHODS

We examined 15 patients with Alzheimer disease, 10 patients with Parkinson disease and dementia (PD-D), 15 patients with PD but no dementia, and 24 age-comparable normal control subjects with a neuropsychologic battery that included tests of explicit memory (Buschke Selective Reminding Test, Benton Visual Retention Test, Digits Span), and tests of implicit memory (Word-Stem Completion task and the Maze Test).

RESULTS

AD and PD-D groups showed similar deficits on all measures of explicit memory, and performed significantly worse than PD patients without dementia and normal control subjects. On the other hand, there were no significant between-group differences in any of the measures of implicit memory.

CONCLUSIONS

Our study demonstrated preserved implicit learning in the context of severe explicit learning deficits in patients with dementia, but could not demonstrate a different profile of memory deficits between so-called cortical and subcortical dementias.

Effect of memantine (NMDA antagonist) on Parkinson's disease: a double-blind crossover randomized study

Our aim was to evaluate the effect of Memantine (1-amino 3,5-dimethyl-adamantane hydrochloride) on cardinal symptoms of Parkinson's disease and on the latency, duration, and magnitude of the response to a single dose of L-Dopa and on drug-induced dyskinesias. Twelve Hoehn-Yahr III-IV patients with idiopathic Parkinson's disease with motor fluctuations and drug-induced dyskinesias were randomized to the NMDA antagonist memantine or placebo in a cross-over design. A single-dose L-Dopa challenge was performed after each medication arm. A significant drug effect on the Unified Parkinson's Disease Rating Scale motor score was observed in "off" and "on" states (F(1,11) = 13.5; p < 0.003). No significant effect on drug-induced dyskinesias was seen. The results suggest that memantine may improve parkinsonian symptoms independently of dopaminergic drugs and, in contrast to recent findings with amantadine, it has no effect on drug-induced dyskinesias.

GPi firing rate modification during beginning-of-dose motor deterioration following acute administration of apomorphine

We present a patient with clinically evident beginning-of-dose motor deterioration who had undergone posteroventral pallidotomy. This patient underwent an intrasurgical apomorphine test followed by single cell recording of the internal globus pallidus (GPi) to determine changes in GPi firing rate during the occurrence of such phenomenon. A significant increase in GPi firing rate coincident with worsening of patient disabilities prior to improvement was found. This finding suggests that beginning-of-dose motor deterioration may be mediated by enhanced thalamic inhibition.

Comparison of 1-year follow-up evaluations of patients with indication for pallidotomy who did not undergo surgery versus patients with Parkinson's disease who did undergo pallidotomy: a case control study

Many reports published during the past 5 years have shown evidence of the beneficial effect of posteroventral pallidotomy (PVP) in large groups of patients for up to 3 years, but none of them have compared patients who underwent surgery with a control group.

OBJECTIVE

To compare the evolution of Parkinson's disease symptoms at 1-year follow-up between patients who underwent surgery and those who did not.

MATERIAL AND METHODS

Ten patients with idiopathic Parkinson's disease refractory to treatment who were included in the Core Assessment for Intracerebral Transplantation program for PVP did not undergo surgery because financial support was lacking. These patients were followed up for 1 year as if they had been operated on and were finally compared with 10 patients having similar characteristics in whom PVP had been performed during the same period of time.

RESULTS

There were no significant differences at basal evaluation in the motor section scores of the Unified Parkinson's Disease Rating Scale between those patients who underwent surgery and those who did not, but a significant reduction in Unified Parkinson's Disease Rating Scale motor score in the group who underwent surgery at 1-year evaluation was found (P < 0.006). Dyskinesias, which was nonsignificantly different at basal evaluation, showed, at the 1-year follow-up, a significant reduction in the group who underwent surgery (P < 0.04). Scores from the subsets of the Unified Parkinson's Disease Rating Scale addressing rigidity, tremor, and bradykinesia also proved significantly different at the 1-year follow-up. The slope of the line generated by the two evaluations for each group showed a negative value in the group who underwent surgery (value of -0.21) and a positive value in the group who did not (value of 0.148).

CONCLUSION

At the 1-year follow-up, microelectrode-guided PVP produced significant changes in patient motor status and disease progression versus a comparable group of patients who did not undergo surgery during the same period of time.

Apomorphine induces changes in GPi spontaneous outflow in patients with Parkinson's disease

OBJECTIVE

To determine the effect of a single dose of apomorphine on internal globus pallidus (GPi) neuronal discharge in patients with Parkinson's disease (PD).

PATIENTS AND METHODS

Nine PD patients who underwent microelectrode-guided posteroventral pallidotomy (PVP) were studied. After identification of a single GPi unit discharge with sufficient spike S/N ratio to allow reliable thresholding, basal recording was followed by a single 3-mg subcutaneous injection. One-minute samples were recorded 10', 30', and 60' after apomorphine.

RESULTS

In four patients, recording was lost after 5-10 minutes. In two, changes were observed at peak-of-dose but recording was then lost, whereas three completed recording and returned to baseline, all five showing significant reduction in GPi firing rate (mean +/- standard deviation for basal and post-apomorphine were 143+/-55.6 and 52+/-19.2, respectively; p <0.002).

CONCLUSION

In patients with PD, apomorphine induces changes in GPi spontaneous discharge and modifies firing rates resembling recordings in normal primates. These findings show that clinical improvement as well as induction of dyskinesias following DA administration could be mediated by reduction of GPi outflow.

Unilateral radiofrequency lesion versus electrostimulation of posteroventral pallidum: a prospective randomized comparison

Microelectrode-guided posteroventral pallidotomy (PVP) has shown to be an effective method in the treatment of a group of patients with advanced Parkinson's disease. A nonlesioning approach by means of deep brain electrodes connected to a programmable neuropacemaker has also been used to inhibit the internal segment of globus pallidus (posteroventral stimulation [PVS]) reporting comparable clinical efficacy to the one obtained with the ablative method. Nevertheless, no controlled studies have been performed to compare the efficacy of both procedures. A prospective series of 13 patients with a clinical indication for globus pallidus surgery was randomized either to a pallidotomy or stimulator implantation, and comparisons on motor and neuropsychologic measurements were made on a 3-month follow-up basis. Primary measurements of efficacy showed a comparable effect on Unified Parkinson's Disease Rating Scale and activities of daily living score after both procedures. Secondary measurements of efficacy showed that although both techniques improve hand tapping score and dyskinesia score, the bilateral improvement in the former was greater after PVS whereas the latter improved more significantly after PVP. No significant changes in neuropsychologic parameters were observed after either PVP or PVS. Side effects and surgery complications occurred in six of 13 patients (three after PVP and three after PVS): they were mild, transient, and unrelated to optic tract injury. In conclusion, the short-time effect and safety of both procedures is comparable.

Confirmation of the antidyskinetic effect of posteroventral pallidotomy by means of an intraoperative apomorphine test

We present a series of six consecutive Parkinson's disease patients undergoing posteroventral pallidotomy (PVP), who received an apomorphine injection after thermolesioning the posteroventral region of the internal globus pallidus (GPi) to evaluate the effect of the lesion on drug-induced dykinesias and therefore to proceed with further lesions or to conclude the surgery. Five of six patients failed to present dykinesias or did so to a significantly lesser degree (F [2,10] 42.6; p < 0.0001) so that surgery was concluded. One patient continued having contralateral dyskinesia despite an improvement in rigidity and bradykinesia, therefore, a new track was performed followed by a new lesion. No differences were found between intrasurgical and 1-month postoperative apomorphine test values. This report indicates that the use of an apomorphine test after thermolesioning may provide a reliable tool to check lesion efficacy on dyskinesia. The development of techniques that provide additional clinical information to the electrophysiological recording could help improve the outcome of patients undergoing pallidotomy.

Changes in the motor response to acute L-dopa challenge after unilateral microelectrode-guided posteroventral pallidotomy

To determine the effect of unilateral posteroventral pallidotomy (PVP) on latency and duration of response to L-dopa ipsilateral and contralateral to the side of the lesion, six severe fluctuating Hoehn-Yahr IV patients with Parkinson's disease were evaluated 2 days before and after unilateral PVP. After an overnight drug holiday in a fasting state, patients were challenged with a single dose of 200/50 mg of L-dopa/ carbidopa. Sequential tapping tests every 5 minutes in both hands were used to measure changes in motor status. Duration of L-dopa effect was significantly longer after PVP (p < 0.03). Mean latency of the effect improved by 50% without reaching statistical significance. Despite a clear, asymmetric improvement of cardinal Parkinson's disease symptoms after unilateral PVP, changes in the dose-response L-dopa profile occurred symmetrically, suggesting that mechanisms underlying the two effects are distinct.

Depression in classic versus akinetic-rigid Parkinson's disease

We examined the prevalence of major depression and dysthymia in 78 patients with the classic variant of Parkinson's disease (PD) (that is, tremor plus rigidity and/or bradykinesia), and in 34 patients with the akinetic-rigid variant. Although the prevalence of dysthymia was similar in both groups (classic PD, 31%; and akinetic-rigid PD, 32%), patients with akinetic-rigid PD had a significantly higher prevalence of major depression (38% versus 15%, respectively; p < 0.01). A stepwise regression analysis demonstrated that bradykinesia was the extrapyramidal sign with the highest correlation with Hamilton depression scale scores. Our findings demonstrate a significant association between major depression and the akinetic-rigid type of PD.

Involuntary movements during thermolesion predict a better outcome after microelectrode guided posteroventral pallidotomy

Eight of the first 15 patients with advanced Parkinson's disease who underwent microelectrode guided posteroventral pallidotomy developed transient abnormal involuntary movements during thermolesion, four of whom also did so during high frequency macrostimulation. Abnormal involuntary movements found before thermolesion were choreic, ballistic, or choreoathetoid in nature, usually persisted less than 60 minutes, and were contralateral to the site of thermolesion in six and bilateral in two of them. The appearance of abnormal involuntary movements during macrostimulation or thermolesion of the internal globus pallidus correlated with better surgical outcome as measured by UPDRS motor items and CAPIT timed test, so that they seem to be of prognostic value.

Sleep benefit in Parkinson's disease

Sleep benefit (SB) In Parkinson's disease (PD) is not well characterized. To determine SB frequency, as well as to characterize and correlate it with other disease variables, we evaluated prospectively a consecutive series of 312 PD patients by means of a structured questionnaire: 55% reported having SB and 35% reported that awakening was their best time of the day. Because of SB, 21% of the entire population were able to skip or delay medication. The mean duration of the phenomenon was 85.4 +/- 67 min. Patients with SB were significantly older (p < 0.0002), had disease longer (p < 0.05), and were often men (chi 2 = 3.5, df 1, p = 0.05). Patients with SB took sleep medication with similar frequency as those without SB. There were no differences in hours of sleep or sleep latency. Sleep problems such as nightmares or somnambulism, but not the number of sleep awakenings, were similar in both groups. In conclusion, SB is a frequent phenomenon, especially in men, elderly patients, and patients with longer disease duration. SB enables the morning L-dopa dose to be postponed in approximately 50% of patients.

Comparison of subcutaneous apomorphine versus dispersible madopar latency and effect duration in Parkinson's disease patients: a double-blind single-dose study

Twelve parkinsonian patients with severely fluctuating symptoms were given a single dose of apomorphine or Dispersible Madopar on 2 consecutive days, to confirm the latter drug's usefulness in "off" period rescue. According to our results, apomorphine proved faster in reverting "off" periods and should still be regarded as the drug of choice for this treatment modality.

Apraxia in Parkinson's disease, progressive supranuclear palsy, multiple system atrophy and neuroleptic-induced parkinsonism

We studied 45 non-demented patients with Parkinson's disease (PD), 12 with progressive supranuclear palsy (PSP), 10 with multiple system atrophy (MSA) and 12 with neuroleptic-induced parkinsonism (NIP) for the presence of apraxia. Our aim was to determine whether a standard comprehensive assessment of different praxic functions would demonstrate specific types of errors not attributable to bradykinesia, rigidity, tremor or any other abnormal elementary motor deficit. PD patients on chronic levodopa treatment were examined in the 'on' and 'off' (treatment) states. Based on apraxia assessment scores, bilateral ideomotor apraxia for transitive movements was found in eight (75%) and 12 (27%) of PSP and PD patients, respectively. Ideomotor apraxia was mainly characterized by spatial errors (i.e., external and internal configuration, body-part-as-object and trajectory). Four PSP but no PD patients exhibited ideomotor apraxia for intransitive movements. PSP as well as PD patients with ideomotor apraxia also had difficulties in imitating hand and finger postures, but none of them failed on pantomime comprehension and pantomime recognition/discrimination. Some PSP patients exhibited, in addition, a limbkinetic type of apraxia and a minority of them displayed deficits on tasks involving multiple steps. Neither MSA nor NIP patients showed any disturbance of praxic functions. There were no differences in age, disease duration, Mini Mental State Examination (MMSE), Unified Parkinson's disease Rating Scale and Hoehn-Yahr scores between apraxic and non-apraxic PD patients, and ideomotor apraxia scores were similar in the 'on' and 'off' states. A correlation was found between ideomotor apraxia scores in PD patients and deficits in frontal lobe-related neuropsychological tasks such as the Tower of Hanoi, verbal fluency and the Trail Making Test. Furthermore, PD patients with apraxia showed higher Hamilton depression scores than non-apraxic PD patients. In PSP patients, ideomotor apraxia scores correlated significantly with cognitive deficit as measured with MMSE. The presence or absence of cortical involvement, and its severity and distribution might determine the presence and type of apraxia in PD and PSP. Apraxia in these conditions would therefore reflect combined cortico-striatal dysfunction.