Does clinical intolerance to a diagnostic acute levodopa challenge differentiate multiple system atrophy from PD?

BACKGROUND

The diagnosis of multiple system atrophy (MSA) remains challenging.

OBJECTIVE

To determine if the occurrence of symptoms of clinical intolerance such as nausea, vomiting, hypotension, and profuse perspiration during a standard acute levodopa challenge may be a useful marker of MSA.

METHODS

A total of 507 dopaminergic acute challenge tests performed for different purposes in the last 10 years in a movement disorders clinic were reviewed, identifying patients who manifested symptoms of clinical intolerance during test performance. Only those tests completed for diagnostic purposes were included and these were matched by the presence or absence of response to levodopa, sex, and age, with a group of patients undergoing acute challenge without any symptoms of clinical intolerance. Presumptive diagnosis for each patient was performed by means of accepted clinical criteria after a significant follow-up period. Only patients with a final diagnosis of Parkinson's disease (PD) or MSA were analyzed.

RESULTS

Twenty-three out of the 507 patients (women: 50%) presented symptoms of clinical intolerance and received a final diagnosis of PD or MSA, and underwent further analysis. Four out the 23 patients with intolerance (17%) and one out the 16 patients from the control group (6%) were diagnosed as having MSA (Chi-square = 1.05, p = .3). Overall sensitivity and specificity of the presence of clinical intolerance to predict diagnosis of MSA were 80% (95%IC: 45%-100%) and 44% (95%CI: 27%-61%) respectively.

CONCLUSIONS

Symptoms of clinical intolerance during an acute levodopa challenge do not appear to be useful in the diagnosis of MSA.

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.

Globus pallidus internus firing rate modification after motor-imagination in three Parkinson's disease patients

Motor imagery is thought to involve the same processes of movement preparation as actual movement. Imagination of a simple repetitive movement significantly decreased the firing rate of extracellular micro recording at sensorimotor neurons of globus pallidus internus in three patients with Parkinson's disease, who underwent microelectrode-guided posteroventral pallidotomy. These findings suggest, in agreement with previous clinical and functional neuroimaging studies that the motor corticostriatal circuit could be engaged in mental simulation.

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.

A validation study of depressive syndromes in Parkinson's disease

The validity, sensitivity, and specificity of depressive symptoms for the diagnosis of major depression, minor depression, dysthymic disorder, and subsyndromal depression in Parkinson's disease (PD) were examined. A consecutive series of 173 patients with PD attending a Movement Disorders Clinic underwent a comprehensive psychiatric and neurological assessment. The symptoms of loss of interest/pleasure, changes in appetite or weight, changes in sleep, low energy, worthlessness or inappropriate guilt, psychomotor retardation/agitation, concentration deficits, and suicide ideation were all significantly associated with the presence of the DSM-IV depressed mood criterion for major depression. The symptoms of changes in appetite, changes in sleep, low energy, low self-esteem, poor concentration, and hopelessness were all significantly associated with the presence of the DSM-IV criterion of sad mood for dysthymic disorder. Thirty percent of our sample met DSM-IV diagnostic criteria for major depression, 20% met diagnostic criteria for dysthymic disorder, 10% met diagnostic criteria for minor depression, and 8% met clinical criteria for subsyndromal depression. Patients with either major or minor depression had significantly more severe deficits in activities of daily living, more severe cognitive impairments, and more severe Parkinsonism than patients with either dysthymic disorder or no depression. This study provides validation to the DSM-IV diagnostic criteria for major depression and dysthymic disorder for use in PD. The categories of minor and subsyndromal depression may need further validation.

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.

Phenomenology of abnormal movements in stuttering

BACKGROUND

Stuttering is often accompanied by involuntary movements, abnormal gestures or changes in facial expression.

OBJECTIVE

To describe the incidence and phenomenology of abnormal movements (AMs) in stuttering patients.

MATERIALS AND METHODS

Eighty-five consecutive patients with stuttering and 119 normal controls videotaped and subsequently reviewed, in which AMs were classified as voluntary or involuntary, and as concurrent or unrelated to speech. Movement phenomenology was correlated with disease severity.

RESULTS

Of 85 stuttering patients studied, 51.7% had AMs and 22 more than one AM. Sixty-six different AMs were identified, of which 83.3% occurred during speech, 72.7% were classified as involuntary, and 27.2% as voluntary. Of 38 involuntary movements concurrent to speech, 25 were originally perceived as voluntary, but had since become involuntary through repeated use during stuttering. All involuntary movements not concurrent to speech fulfilled criteria for tics.

CONCLUSION

AMs occurring during stuttering were not always involuntary; movements not concurrent with speech clearly fulfilled clinical criteria for tics and were similar in incidence to normal controls. Inverse correlation was found between conscious control of movement during speech and stuttering severity. Many involuntary movements occurring during speech were clearly referred by patients as initially voluntary early on in the development of their speech disorder (starters or unblockers), underlining the importance of repetitive use of complex motor sequences as a source for putative involuntary movement genesis.

The Unified Parkinson's Disease Rating Scale: Validation study of the mentation, behavior, and mood section

The objective of this study was to examine the validity of the mentation, behavior, and mood items included in Part I of the Unified Parkinson's Disease Rating Scale (UPDRS) and to assess its usefulness to screen for dementia, psychosis, depression, and apathy. A consecutive series of 168 patients with PD were assessed by neurologists with the UPDRS, and by psychiatrists using a comprehensive neuropsychiatric evaluation blind to each other's ratings. ROC analysis demonstrated that a score of 2 or greater on the intellectual impairment item of the UPDRS had 60% sensitivity and 92% specificity to detect dementia, as diagnosed with DSM-IV criteria. When a score of 23 or lower on the MMSE was included as an additional classification variable, the sensitivity increased to 85%. A score of 2 or greater on the thought disorder item had 43% sensitivity and 92% specificity to detect psychotic symptoms (delusions or hallucinations). A score of 2 or greater on the depression item had 77% sensitivity and 82% specificity to detect major depression as diagnosed with DSM-IV criteria. Finally, a score of 2 or greater on the motivation/initiative item had 73% sensitivity and 65% specificity to detect apathy, as diagnosed with a standardized criteria. When the sample was divided into mild (i.e. Hohen-Yahr stages I and II) versus moderate-severe PD (i.e. Hohen-Yahr stages III-V), findings remained unchanged, except that the UPDRS show unacceptably low accuracy to detect psychosis in mild PD. The mentation, behavior, and mood section of the UPDRS is an adequate screen for depression and apathy, and has adequate sensitivity to detect dementia when combined with the Mini-Mental State Exam, but has low sensitivity to detect psychosis.

The athlete with muscular cramps: clinical approach

Muscle cramps are involuntary, painful, spasmodic contractions of the skeletal muscle. Although cramps are a common clinical complaint, their etiology and management have not been well established. Exercise-associated muscle cramps occur during or immediately following exercise, and they are associated with muscular fatigue and shortened muscle contraction. The main challenges for treating physicians are to identify whether the complaint represents a true muscle cramp as well as to rule out the presence of an underlying serious clinical condition. Muscle cramps may be a symptom of any of several conditions, including radiculopathies, Parkinson's disease, hypothyroidism, diabetes mellitus, vascular problems, electrolyte disorders, and metabolic myopathies. Cramps also may occur as a side effect of certain drugs (eg, lipid-lowering agents, antihypertensives, beta-agonists, insulin, oral contraceptives, alcohol). Most athletes who experience exercise-associated muscle cramps are healthy individuals without systemic illness. Therapy should focus on preventing premature fatigue by means of appropriate nutrition and adequate training.

Validation of a new scale for the evaluation of sialorrhea in patients with Parkinson's disease

Sialorrhea is common in Parkinson disease (PD), affecting approximately 70% to 75% of patients. Several tools for measuring saliva volume or production exist, but none are designed specifically for assessing sialorrhea-related discomfort. The objective of this study was to develop and validate a clinical scale for subjective evaluation of sialorrhea in PD. In Phase I, internal consistency of the Sialorrhea Clinical Scale for PD (SCS-PD) was established in 39 PD patients. In Phase II, scale validity was proven through saliva volume measurements obtained in 49 PD patients and 27 healthy volunteers. Internal consistency estimated using Cronbach's alpha was 0.78, indicating none of the original seven items tested needed to be removed. Twenty-one patients complaining of sialorrhea (63%) studied during Phase II, showed higher SCS-PD scores but no differences in saliva volume. SCS-PD scores showed significant correlation with saliva volume (r = 0.41; P = 0.004) and with total Unified Parkinson's Disease Rating Scale Part III (UPDRS III) scores (r = 0.70). Furthermore, saliva volume showed inverse relation to age in PD patients as well as in controls (r = -0.3 and r = -0.4; P < 0.05), but SCS-PD scores did not. The SCS-PD scale showed good internal consistency and validity, providing support for its use in routine clinical sialorrhea-related discomfort evaluation.

Neuronal activity of the zona incerta in Parkinson's disease patients

The objective of this study was to describe the firing characteristics of the zona incerta (ZI) in Parkinson's disease patients. The ZI constitutes a band of gray matter lying dorsal to the subthalamic nucleus, whose firing properties have not been well defined in humans yet. ZI proved to become hyperactive in 6-OHDA-lesioned rats as compared to normal rats, and regarding these noticeable changes in the discharge patterns it was suggested that ZI could be a putative target for the surgical treatment of Parkinson's disease. Twelve patients who underwent microrecording-guided subthalamic surgery consented to the study. Neurons from different tracts were classified as belonging to the ZI according to their firing features, background extracellular activity, anatomical mapping of trajectories, and atlas confirmation. Fifty-nine neurons were classified as belonging to ZI. The mean firing rate proved to be 29.5 Hz, with a broad dispersion band, even covering subthalamic nucleus (STN) frequency ranges. Pattern analysis showed heterogeneous neuronal signals ranging from tonic to burst and paused neurons. A decrease in extracellular background activity in the defined ZI was also observed. Five of the recorded neurons showed rhythmical spike trains with oscillations of 8 to 14 Hz, and two units were found to discharge trains at 4 Hz. None of the recorded ZI neurons responded to proprioceptive maneuvers. ZI presented firing activities with a broad spectrum in terms of frequency and tonicity. It is differentiated from STN recordings in Parkinson's disease patients mainly because of absent proprioceptive-related units and diminished extracellular background activity.

Julio Cortázar quotes on normal and abnormal movements: magical realism or reality?

Together with Mario Vargas Llosa and Gabriel García Márquez, Julio Cortázar was one of the most representative authors of the Latin American magical realism genre. Within his extensive body of work, many descriptions of characters suffering physical disabilities, as well as situations suggesting such medical conditions, can be extracted. In this review, two short stories by Cortázar are presented. In the first one, the main character could easily be a man suffering from corticobasal degeneration; in the second, an old woman with symptoms suggestive of progressive supranuclear palsy is clearly depicted. Despite the fact that one of the main ingredients in Cortázar's magical realism is fiction, cases described here fit real medical conditions quite well, making it hard to believe that they represent purely fantastic descriptions rather than the product of Cortázar's inquisitive observation and the description of real patients.

Bilateral mirror writing movements (mirror dystonia) in a patient with writer's cramp: Functional correlates

A recent prospective analysis on writer's cramp showed that up to 44.6% of patients in a series of 65 presented mirror dystonia, defined as involuntary movements of the resting hand, abnormal posture, tremor, and jerks occurring while writing with the opposite hand. A clinical case is presented, with videotape evidence of right-handed writer's cramp, with mirror movements elicited while writing using either hand. Functional magnetic resonance imaging studies are compared both to those of a normal patient and to those from a patient with writer's cramp but lacking mirror dystonia. Widespread bilateral activation of cortical motor areas contralateral to the mirror movements in patients with writer's cramp and mirror movements suggests, that bilateral activation of the primary motor cortex may account for the appearance of these mirror movements. Further studies need to be conducted to determine whether mirror movements in dystonic patients appear as a result of loss of intra- and/or interhemispheric cortical inhibition or are simply a consequence of the sustained effort these patients need to exert while writing using a dystonic hand.

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.

The Parkinson-Control study: A 1-year randomized, double-blind trial comparing piribedil (150 mg/day) with bromocriptine (25 mg/day) in early combination with levodopa in Parkinson's disease

Dopamine agonists have been recommended as early treatment for Parkinson's disease (PD), alone or combined with levodopa. Piribedil is a non-ergot selective D(2)/D(3) agonist with alpha(2) antagonist properties shown to be effective in the treatment of PD. This 12-month international, randomized, double-blind trial aimed to assess the efficacy of piribedil 150 mg versus bromocriptine 25 mg, in early combination with levodopa in Stage I to III PD patients. Motor efficacy was assessed using the Unified Parkinson's Disease Rating Scale (UPDRS III, Items 18-31) as improvement from baseline. Response rate was defined as a 30% improvement. Among the 425 randomly assigned patients, 178 were also included in a substudy on cognitive follow-up evaluated by a dysexecutive syndrome oriented battery. A relevant improvement in UPDRS III over the 12-month study duration was observed both in the piribedil and bromocriptine groups (-7.9 +/- 9.7 points from baseline versus -8.0 +/- 9.5; not significant [n.s.]) with a response rate of 58.4% and 55.3% (n.s.), respectively. Piribedil and bromocriptine resulted in similar improvement on all UPDRS III subscores. Piribedil patients required less levodopa dose increase than those on bromocriptine. Cognitive performance remained generally unchanged in both groups, with a significant effect of piribedil limited to the Wisconsin Card Sorting Test. An overall good tolerability of piribedil was observed. Early combination of piribedil 150 mg with levodopa resulted in significant long-term improvement of all motor symptoms in PD patients insufficiently controlled by levodopa alone. Taking into account both efficacy and acceptability in the long-term, piribedil proved in this bromocriptine controlled study to be an effective and safe treatment for PD.