Bee Venom for the Treatment of Parkinson Disease - A Randomized Controlled Clinical Trial

In the present study, we examined the potential symptomatic and/or disease-modifying effects of monthly bee venom injections compared to placebo in moderatly affected Parkinson disease patients. We conducted a prospective, randomized double-blind study in 40 Parkinson disease patients at Hoehn & Yahr stages 1.5 to 3 who were either assigned to monthly bee venom injections or equivalent volumes of saline (treatment/placebo group: n = 20/20). The primary objective of this study was to assess a potential symptomatic effect of s.c. bee venom injections (100 μg) compared to placebo 11 months after initiation of therapy on United Parkinson’s Disease Rating Scale (UPDRS) III scores in the « off » condition pre-and post-injection at a 60 minute interval. Secondary objectives included the evolution of UPDRS III scores over the study period and [123I]-FP-CIT scans to evaluate disease progression. Finally, safety was assessed by monitoring specific IgE against bee venom and skin tests when necessary. After an 11 month period of monthly administration, bee venom did not significantly decrease UPDRS III scores in the « off » condition. Also, UPDRS III scores over the study course, and nuclear imaging, did not differ significantly between treatment groups. Four patients were excluded during the trial due to positive skin tests but no systemic allergic reaction was recorded. After an initial increase, specific IgE against bee venom decreased in all patients completing the trial. This study did not evidence any clear symptomatic or disease-modifying effects of monthly bee venom injections over an 11 month period compared to placebo using a standard bee venom allergy desensitization protocol in Parkinson disease patients. However, bee venom administration appeared safe in non-allergic subjects. Thus, we suggest that higher administration frequency and possibly higher individual doses of bee venom may reveal its potency in treating Parkinson disease.

Executive functioning and risk-taking behavior in Parkinson's disease patients with impulse control disorders

Impulse control disorders (ICD) are common in Parkinson's disease (PD) and are associated with dopaminergic medication. The purpose of this study was to investigate executive function and risk-taking behavior in PD patients with ICD. 17 PD patients with ICD (ICD-PD) were compared to 20 PD patients without ICD (CTRL-PD) using neuropsychological and experimental tasks. Executive functions were assessed using standard executive testing (Conner's Performance Test, Modified Wisconsin Card Sorting Test, Trail Making Test and phonological verbal fluency). Subjects were also submitted to an experimental gambling task consisted of three decks of money cards: neutral deck (equal opportunity for gains as losses), winning deck (small amount of money with a positive balance) and loser deck (high amount of money with a negative balance), evaluating risk-taking behavior (number of cards picked in each deck) and valuation of the reward (subjective appreciation of the value of each deck). There was no significant difference in executive functioning between groups. Both groups selected more cards in the losing deck (high amount of money) as compared to the neutral deck (Mann-Whitney test, ICD-PD, p = 0.02; CTRL-PD, p = 0.003) and to the winning deck (Mann-Whitney test, ICD-PD p = 0.0001; CTRL-PD p = 0.003), suggesting an increased risk-taking behavior. Interestingly, we found that ICD-PD patients estimated the value of decks differently from CTRL-PD patients, taking into account mainly the positive reinforced value of the decks (Mann-Whitney test, p = 0.04). This study showed that executive pattern and risk-taking behavior are similar between ICD-PD and CTRL-PD patients. However, ICD-PD patients showed a specific deficit of the subjective estimation of the reward. Links between this deficit and metacognitive skills are discussed.

Loss of VPS13C Function in Autosomal-Recessive Parkinsonism Causes Mitochondrial Dysfunction and Increases PINK1/Parkin-Dependent Mitophagy

Autosomal-recessive early-onset parkinsonism is clinically and genetically heterogeneous. The genetic causes of approximately 50% of autosomal-recessive early-onset forms of Parkinson disease (PD) remain to be elucidated. Homozygozity mapping and exome sequencing in 62 isolated individuals with early-onset parkinsonism and confirmed consanguinity followed by data mining in the exomes of 1,348 PD-affected individuals identified, in three isolated subjects, homozygous or compound heterozygous truncating mutations in vacuolar protein sorting 13C (VPS13C). VPS13C mutations are associated with a distinct form of early-onset parkinsonism characterized by rapid and severe disease progression and early cognitive decline; the pathological features were striking and reminiscent of diffuse Lewy body disease. In cell models, VPS13C partly localized to the outer membrane of mitochondria. Silencing of VPS13C was associated with lower mitochondrial membrane potential, mitochondrial fragmentation, increased respiration rates, exacerbated PINK1/Parkin-dependent mitophagy, and transcriptional upregulation of PARK2 in response to mitochondrial damage. This work suggests that loss of function of VPS13C is a cause of autosomal-recessive early-onset parkinsonism with a distinctive phenotype of rapid and severe progression.

Contribution of ATXN2 intermediary polyQ expansions in a spectrum of neurodegenerative disorders

OBJECTIVE

The aim of this study was to establish the frequency of ATXN2 polyglutamine (polyQ) expansion in large cohorts of patients with amyotrophic lateral sclerosis (ALS), frontotemporal dementia (FTD), and progressive supranuclear palsy (PSP), and to evaluate whether ATXN2 could act as a modifier gene in patients carrying the C9orf72 expansion.

METHODS

We screened a large cohort of French patients (1,144 ALS, 203 FTD, 168 FTD-ALS, and 109 PSP) for ATXN2 CAG repeat length. We included in our cohort 322 carriers of the C9orf72 expansion (202 ALS, 63 FTD, and 57 FTD-ALS).

RESULTS

We found a significant association with intermediate repeat size (≥29 CAG) in patients with ALS (both familial and sporadic) and, for the first time, in patients with familial FTD-ALS. Of interest, we found the co-occurrence of pathogenic C9orf72 expansion in 23.2% of ATXN2 intermediate-repeat carriers, all in the FTD-ALS and familial ALS subgroups. In the cohort of C9orf72 carriers, 3.1% of patients also carried an intermediate ATXN2 repeat length. ATXN2 repeat lengths in patients with PSP and FTD were found to be similar to the controls.

CONCLUSIONS

ATXN2 intermediary repeat length is a strong risk factor for ALS and FTD-ALS. Furthermore, we propose that ATXN2 polyQ expansions could act as a strong modifier of the FTD phenotype in the presence of a C9orf72 repeat expansion, leading to the development of clinical signs featuring both FTD and ALS.

DCTN1 mutation analysis in families with progressive supranuclear palsy-like phenotypes

IMPORTANCE

Progressive supranuclear palsy (PSP) is usually sporadic, but few pedigrees with familial clustering of PSP-like phenotypes have been described. Occasionally, MAPT, C9ORF72, and TARDBP mutations have been identified.

OBJECTIVE

To analyze the DCTN1 gene in 19 families with a clinical phenotype of PSP (PSP-like phenotype).

DESIGN, SETTING, AND PARTICIPANTS

Sequencing of the DCTN1 gene in familial forms of PSP at a referral center among 21 patients with familial PSP-like phenotypes. In addition, 8 patients and relatives from a family carrying a DCTN1 mutation were evaluated.

MAIN OUTCOMES AND MEASURES

Identification of the DCTN1 mutation and clinical description of DCTN1 mutation carriers.

RESULTS

We identified a DCTN1 mutation in a large family characterized by high intrafamilial clinical phenotype variability. Two patients had PSP-like phenotypes with dystonia, vertical gaze slowness, dysexecutive syndrome, predominant axial rigidity, and midbrain atrophy on brain magnetic resonance imaging. The other patients manifested Perry syndrome, isolated parkinsonism, or a predominant behavioral variant of frontotemporal dementia.

CONCLUSIONS AND RELEVANCE

Mutations of the DCTN1 gene have been previously associated with amyotrophic lateral sclerosis and with Perry syndrome, a rare autosomal dominant disorder characterized by weight loss, parkinsonism, central hypoventilation, and psychiatric disturbances. Our study demonstrates that DCTN1 mutations should be searched for in patients with clinical PSP-like phenotypes and a behavioral variant of frontotemporal dementia, especially when a familial history of dementia, psychiatric disturbances, associated parkinsonism, or an autosomal dominant disorder is present.

Optimal target localization for subthalamic stimulation in patients with Parkinson disease

Objective:

To further determine the causes of variable outcome from deep brain stimulation of the subthalamic nucleus (DBS-STN) in patients with Parkinson disease (PD).

Methods:

Data were obtained from our cohort of 309 patients with PD who underwent DBS-STN between 1996 and 2009. We examined the relationship between the 1-year motor, cognitive, and psychiatric outcomes and (1) preoperative PD clinical features, (2) MRI measures, (3) surgical procedure, and (4) locations of therapeutic contacts.

Results:

Pre- and postoperative results were obtained in 262 patients with PD. The best motor outcome was obtained when stimulating contacts were located within the STN as compared with the zona incerta (64% vs 49% improvement). Eighteen percent of the patients presented a postoperative cognitive decline, which was found to be principally related to the surgical procedure. Other factors predictive of poor cognitive outcome were perioperative confusion and psychosis. Nineteen patients showed a stimulation-induced hypomania, which was related to both the form of the disease (younger age, shorter disease duration, higher levodopa responsiveness) and the ventral contact location. Postoperative depression was more frequent in patients already showing preoperative depressive and/or residual axial motor symptoms.

Conclusion:

In this homogeneous cohort of patients with PD, we showed that (1) the STN is the best target to improve motor symptoms, (2) postoperative cognitive deficit is mainly related to the surgery itself, and (3) stimulation-induced hypomania is related to a combination of both the disease characteristics and a more ventral STN location.

Withdrawing amantadine in dyskinetic patients with Parkinson disease: the AMANDYSK trial

OBJECTIVE

The AMANDYSK trial was designed to assess long-term efficacy of chronic treatment with amantadine in patients with Parkinson disease (PD) and levodopa-induced dyskinesia (LID).

METHODS

This was a 3-month, multicenter, randomized, double-blind, placebo-controlled, parallel-group, wash-out study conducted in 57 amantadine-treated (≥200 mg/d for ≥6 months) dyskinetic patients with PD. The primary outcome measure was the change from baseline in a Unified Parkinson's Disease Rating Scale (UPDRS) dyskinesia subscore (items 32 [duration] + 33 [severity]). Secondary outcomes included other LID measurements ("responders" analysis, premature dropout for LID, Abnormal Involuntary Movement Scale). Exploratory outcomes included time with troublesome dyskinesia as measured by diaries, UPDRS Motor Examination (part III) for motor symptoms of PD, and fatigue and apathy scores for nonmotor symptoms.

RESULTS

UPDRS items 32 + 33 deteriorated more in patients switched to placebo ("discontinuing" group) (+1.7 ± 2.0 units; 95% confidence interval 0.9, 2.4) as compared with those maintained on amantadine ("continuing" group) (+0.2 ± 1.5 units; 95% confidence interval -0.4, 0.8; p = 0.003). Secondary outcomes confirmed this difference because there were significantly more responders, more dropouts for LID, greater increase in "ON" time with troublesome dyskinesia, and greater worsening of Abnormal Involuntary Movement Scale score in the discontinuing group. There were no between-group differences in the UPDRS Motor Examination, whereas apathy (as measured by caregivers) and fatigue scores tended to worsen more in patients randomized to placebo.

CONCLUSION

Wash-out of amantadine in dyskinetic patients with PD significantly worsened LID. No significant effect was observed on motor parkinsonian symptoms, while exploratory outcomes suggested that amantadine might improve apathy and fatigue in such patients.

CLASSIFICATION OF EVIDENCE

This article provides Class II evidence that in patients with PD, withdrawing amantadine significantly aggravates LID in a median time of 7 days.

Dopa-decarboxylase gene polymorphisms affect the motor response to L-dopa in Parkinson's disease

BACKGROUND

In Parkinson's disease (PD), the response to L-dopa is highly variable and unpredictable. The major pathway for dopamine synthesis from L-dopa is decarboxylation by aromatic L-amino acid decarboxylase (AAAD, encoded by the DDC gene).

OBJECTIVE

To determine the motor response to L-dopa in PD patients as a function of the DDC gene promoter polymorphisms (rs921451 T > C polymorphism (DDC(T/C)) and rs3837091 AGAG del (DDC(AGAG/-))).

METHODS

Thirty-three Caucasian PD patients underwent an acute l-dopa challenge together with the peripheral AAAD inhibitor benserazide and were genotyped for rs921451 and rs3837091. The primary efficacy criterion was the motor response to L-dopa, as estimated by the area under the curve for the change in the Unified Parkinson's Disease Rating Scale part III (UPDRS) score relative to baseline (AUCΔUPDRS) in the 4 h following L-dopa administration. Secondary endpoints were pharmacokinetic parameters for plasma levels of L-dopa and dopamine. Investigators and patients were blinded to genotypes data throughout the study.

RESULTS

When adjusted for the L-dopa dose, the AUCΔUPDRS was significantly lower in DDC(CC/CT) patients (n = 14) than in DDC(TT) patients (n = 19) and significantly lower in DDC(-/- or AGAG/-) patients (n = 8) than in DDC(AGAG/AGAG) patients (n = 25). There were no significant intergroup differences in plasma pharmacokinetic parameters for L-dopa and dopamine.

DISCUSSION

The rs921451 and rs3837091 polymorphisms of the DDC gene promoter influence the motor response to L-dopa but do not significantly change peripheral pharmacokinetic parameters for L-dopa and dopamine. Our results suggest that DDC may be a genetic modifier of the l-dopa response in Parkinson's disease.

Disease severity and progression in progressive supranuclear palsy and multiple system atrophy: validation of the NNIPPS--Parkinson Plus Scale

Background

The Natural History and Neuroprotection in Parkinson Plus Syndromes (NNIPPS) study was a large phase III randomized placebo-controlled trial of riluzole in Progressive Supranuclear Palsy (PSP, n = 362) and Multiple System Atrophy (MSA, n = 398). To assess disease severity and progression, we constructed and validated a new clinical rating scale as an ancillary study.

Methods and Findings

Patients were assessed at entry and 6-montly for up to 3 years. Evaluation of the scale's psychometric properties included reliability (n = 116), validity (n = 760), and responsiveness (n = 642). Among the 85 items of the initial scale, factor analysis revealed 83 items contributing to 15 clinically relevant dimensions, including Activity of daily Living/Mobility, Axial bradykinesia, Limb bradykinesia, Rigidity, Oculomotor, Cerebellar, Bulbar/Pseudo-bulbar, Mental, Orthostatic, Urinary, Limb dystonia, Axial dystonia, Pyramidal, Myoclonus and Tremor. All but the Pyramidal dimension demonstrated good internal consistency (Cronbach α≥0.70). Inter-rater reliability was high for the total score (Intra-class coefficient = 0.94) and 9 dimensions (Intra-class coefficient = 0.80–0.93), and moderate (Intra-class coefficient = 0.54–0.77) for 6. Correlations of the total score with other clinical measures of severity were good (rho≥0.70). The total score was significantly and linearly related to survival (p<0.0001). Responsiveness expressed as the Standardized Response Mean was high for the total score slope of change (SRM = 1.10), though higher in PSP (SRM = 1.25) than in MSA (SRM = 1.0), indicating a more rapid progression of PSP. The slope of change was constant with increasing disease severity demonstrating good linearity of the scale throughout disease stages. Although MSA and PSP differed quantitatively on the total score at entry and on rate of progression, the relative contribution of clinical dimensions to overall severity and progression was similar.

Conclusions

The NNIPPS-PPS has suitable validity, is reliable and sensitive, and therefore is appropriate for use in clinical studies with PSP or MSA.

Trial Registration

ClinicalTrials.gov NCT00211224

The COMT Val158Met polymorphism affects the response to entacapone in Parkinson's disease: a randomized crossover clinical trial

OBJECTIVE

In Parkinson disease (PD), the selective C-O-methyltransferase (COMT) inhibitor entacapone prolongs the effect of levodopa on motor symptoms (ON time) by increasing its bioavailability. The COMT Val158Met polymorphism is equally distributed in PD patients and modulates COMT activity, which can be high (Val/Val, COMT(HH) ), intermediate (Val/Met, COMT(HL) ), or low (Met/Met, COMT(LL) ). The objective of this study was to determine the response to entacapone in COMT(HH) and COMT(LL) PD patients.

METHODS

Thirty-three PD patients, homozygous for the COMT alleles COMT(HH) (n = 17) and COMT(LL) (n = 16), were randomized in a double-blind crossover trial consisting of 2 successive acute levodopa challenges associated with 200mg entacapone or placebo. The primary endpoint was the gain in the best ON time. Secondary endpoints were levodopa pharmacokinetics and COMT activity in red blood cells.

RESULTS

The gain in the best ON time was higher in COMT(HH) than in COMT(LL) patients (39 ± 10 vs 9 ± 9 minutes, p = 0.04, interaction between treatment and genotype). Area under the concentration over time curve of levodopa increased more after entacapone in COMT(HH) than in COMT(LL) patients (+62 ± 6% vs +34 ± 8%, p = 0.01). COMT inhibition by entacapone was higher in COMT(HH) than in COMT(LL) patients (-0.54 ± 0.07 vs -0.31 ± 0.06 pmol/min/mg protein, p = 0.02).

INTERPRETATION

The COMT(HH) genotype in PD patients enhances the effect of entacapone on the pharmacodynamics and pharmacokinetics of levodopa. The response to entacapone after repeated administrations and in heterozygous patients remains to be determined.

Urodynamic analysis in multiple system atrophy: characterisation of detrusor-sphincter dyssynergia

In multiple system atrophy (MSA), parkinsonism and a cerebellar syndrome are associated with autonomic dysfunction. Both bladder neck dysfunction and external sphincter denervation have been implicated in detrusor-sphincter dyssynergia. However, urethral dysfunction may not be adequately reflected by a single global measurement of urethral pressure. Pressure assessment at several levels of the urethra is needed to unravel the mechanisms of bladder-urethra dysfunction. Here, we evaluated the use of multiple sensor pressure transducers to assess bladder-sphincter function in 52 patients with MSA in comparison to patients with Parkinson's disease (PD) who were matched for age and severity in the "off" condition. Urinary dysfunction appeared significantly earlier in MSA (<2 years) than in PD (>5 years). Detrusor under-activity with dysuria was observed in 58% of MSA patients within 4 years and in 76% of patients thereafter. Detrusor-urethral dyssynergia in MSA patients was always better characterized by multiple sensor pressure transducer measurement of bladder and urethral pressure than by a single global measurement. This new approach may prove useful for differential diagnosis of parkinsonian syndromes, and especially MSA.

Orodispersible sublingual piribedil to abort OFF episodes: a single dose placebo-controlled, randomized, double-blind, cross-over study

S90049, a novel sublingual formulation of the non-ergoline D(2)-D(3) agonist piribedil, has a pharmacokinetic profile promising to provide rapid relief on motor signs in Parkinson's disease (PD). We assessed the efficacy and safety of S90049 in aborting OFF episodes responding to subcutaneous apomorphine in PD patients with motor fluctuations. This was a single-dose double-blind double-placebo 3 x 3 cross-over study. Optimal tested doses were determined during a previous open-label titration phase (S90049 median dose: 60 mg, apomorphine: 5 mg). Primary endpoint was the maximal change versus baseline in UPDRS motor score (Delta UPDRS III) assessed after drug administration following an overnight withdrawal of antiparkinsonian medications. Thirty patients (age: 60 +/- 8 years, PD duration: 12 +/- 6 years, UPDRS III OFF: 37 +/- 15) participated. S90049 was superior to placebo on Delta UPDRS III (-13 +/- 12 versus -7 +/- 9 respectively; estimated difference -5.2, 95% Confidence Interval (CI)[-10.4;0.05], P = 0.05). This was also true for secondary outcomes: number of patients switching from OFF to ON (17 on S90049 vs. 8 on placebo, P = 0.03), time to turn ON (P = 0.013) and duration of the ON phase (P = 0.03). In the 17 patients who switched ON on S90049, Delta UPDRS III was similar on S90049 (-21.2 +/- 10.1) and apomorphine (-23.6 +/- 14.1) (estimated difference: 4.0 95% CI [-2.9;10.9]). S90049 was well tolerated: no serious or unexpected adverse event occurred. A single dose of up to 60 mg of S90049 given sublingually was superior to placebo in improving UPDRS III and aborting a practical OFF in patients with advanced PD. Testing greater doses might improve response rate.

Quality of life in relation to mood, coping strategies, and dyskinesia in Parkinson's disease

Given the variability of the results found in the literature, the current study is a step toward better clarifying the influence of motor and nonmotor factors on quality of life in Parkinson's disease. A total of 135 participants with Parkinson's disease were selected. Semistructured interviews were carried out, after which their mental and cognitive states were assessed using different scales (MINI, MADRS, EHD, HAMA). Finally, all participants completed 3 self-report questionnaires: 2 assessing coping strategies (WCC, CHIP) and 1, quality of life (Parkinson's disease questionnaire-39). It appears that the presence of dyskinesia, depression, and anxiety were linked to a poor quality of life. Interestingly, some different coping strategies, namely diversion as well as emotional strategies, were associated with a poor quality of life. These results encourage us to develop interventions focused on coping strategies and tailored to the emotional and clinical characteristics of each patient.

Alpha-synuclein gene rearrangements in dominantly inherited parkinsonism: frequency, phenotype, and mechanisms

OBJECTIVE

Genomic multiplications of the alpha-synuclein gene (SNCA) cause autosomal dominant Parkinson disease (ADPD). The aim of this study was to assess the frequency and phenotype of SNCA rearrangements in a large series of families with typical or atypical AD parkinsonism.

DESIGN

Patients were screened by the exon dosage of the SNCA gene. The genotype of patients and relatives carrying SNCA rearrangements, the size of the multiplied regions, and the centromeric and telomeric breakpoints were determined by microsatellite dosage and 250K Affymetrix Single Polymorphism Nucleotide microarrays (Affymetrix, Santa Clara, California).

SUBJECTS

Index cases and, whenever appropriate, relatives of 286 mainly European families with ADPD were screened.

RESULTS

Four of 264 families (1.5%) with typical ADPD carried duplications and 1 of 22 families (4.5%) with atypical AD parkinsonism carried a triplication of SNCA. Genotyping and dosage analyses showed that the multiplied regions were variable in size (0.42-5.29 megabase pairs), suggesting that SNCA multiplications occurred independently. Phenotype analyses showed that the severity of the disease correlated with the SNCA copy number, but not with the minimal number of multiplied genes (1 to 33). Haplotype analysis of polymorphic markers suggested that multiplication of the SNCA gene occurred by both interchromosomal and intrachromosomal rearrangement.

CONCLUSIONS

Our results suggest that SNCA rearrangements may be more frequent than point mutations in ADPD. Furthermore, our results indicate that the phenotype associated with SNCA multiplications correlates with the number of copies of the gene and provides the first insight into the mechanisms underlying SNCA multiplication.

Working memory in Parkinson's disease patients: clinical features and response to levodopa

OBJECTIVE: To evaluate the clinical features of the working memory (WM) in Parkinson's disease (PD) patients and to test the effect of levodopa on WM. METHOD: The paradigm was based on the 'n-back' tasks, which enables to study the level of executive demand (three levels of difficulty) and the domain of the information being processed (spatial items, faces and letters). The effect of levodopa was studied by testing PD patients in "on" and "off" states. RESULTS: PD patients performed less well in WM tasks than controls. There was no interaction between groups and complexity. Levodopa therapy had a positive effect only on spatial WM tasks but no effect on complexity. CONCLUSION: Our results suggest that impairment observed may result from a maintenance deficit within WM regardless the level of processing and levodopa therapy presents a positive effect on spatial WM.

Camptocormia and Parkinson's disease: MR imaging

Camptocormia is characterized by an excessive anterior flexion of the spine that appears only when standing or walking. The origin of this symptom remains unknown, but recent clinical reports of camptocormia associated with Parkinson's disease (PD) suggest cerebral involvement in the pathogenesis of camptocormia. This study was undertaken to investigate the hypothesis that camptocormia in PD has a central origin. Seventeen PD patients with camptocormia were prospectively enrolled and were compared to 10 matched PD patients without camptocormia and 12 normal controls. The normalized volumes of the brain, striatal nuclei, and the cross-sectional areas of the midbrain and pons were measured on three-dimensional magnetic resonance imaging. Data were correlated with the severity of the symptoms. The normalized axial surface of the midbrain was statistically smaller in PD patients with camptocormia than in normal controls (P = 0.01). The normalized volumetric data were not statistically different in PD patients with camptocormia. There was a significant negative correlation between the severity of camptocormia and the normalized brain volume (P < 0.009; R = -0.649) and sagittal pons area (P < 0.01; R = -0.642). The results suggest that PD with camptocormia may represent a selective form of PD in which a specific neuronal dysfunction possibly occurs within the brainstem.

LRRK2 exon 41 mutations in sporadic Parkinson disease in Europeans

BACKGROUND

Mutations in leucine-rich repeat kinase 2 gene (LRRK2), particularly the G2019S mutation in exon 41, have been detected in familial and sporadic Parkinson disease (PD) cases.

OBJECTIVES

To assess the frequency of LRRK2 exon 41 mutations in a series of sporadic PD cases from Europe and to determine the clinical features of LRRK2 mutation carriers.

DESIGN

We analyzed European cases of sporadic PD for the presence of LRRK2 exon 41 mutations. These mutations were screened by denaturing high-performance liquid chromatography, and abnormal chromatograph traces were investigated by direct sequencing to determine the exact nature of the variants. Early-onset sporadic PD cases were also screened for parkin mutations. The haplotypes associated with the G2019S mutation were determined. The clinical characteristics of patients carrying LRRK2 mutations were detailed.

SETTING

French Network for the Study of Parkinson Disease Genetics. Patients Three hundred twenty patients with apparently sporadic PD from Europe.

MAIN OUTCOME MEASURES

Results of genetic analyses.

RESULTS

We found the G2019S mutation in 6 patients and identified 2 new variants (Y2006H and T2031S) in 1 patient each. Their clinical features were similar to those of typical PD. All G2019S mutation carriers shared a common haplotype.

CONCLUSIONS

The G2019S mutation is almost as frequent in sporadic cases (1.9%) as in previously reported familial cases (2.9%) in Europe and occurs in the same common founder. We identified 2 novel variants. Although the phenotype of LRRK2 mutation carriers closely resembles that of typical PD, the age at onset was younger (29 years in 1 patient) than previously described, and 3 patients were improved by deep brain stimulation.

Neurosurgery at an earlier stage of Parkinson disease: A randomized, controlled trial

BACKGROUND

Stimulation of the subthalamic nucleus is an effective treatment for advanced Parkinson disease (PD) and is currently performed after a mean disease duration of 14 years, when severe motor complications have resulted in marked loss of quality of life. We examined whether surgery at an early stage would maintain quality of life as well as improve motor function.

METHODS

Twenty patients with PD of short duration (time elapsed since first symptom +/- SD: 6.8 +/- 1.0 years) with mild to moderate motor signs (Unified Parkinson's Disease Rating Scale III "off" medication: 29 +/- 12) who responded well to levodopa treatment were included in pairs, matched for age, duration and severity of disease, and impairment in socioprofessional functioning. Patients were prospectively randomized to undergo bilateral subthalamic nucleus stimulation (n = 10) or receive optimized medical treatment (n = 10). Parkinsonian motor scores, quality of life, cognition, and psychiatric morbidity were assessed at inclusion and at 6, 12, and 18 months after randomization.

RESULTS

Quality of life was improved by 24% in surgical and 0% in nonsurgical patients (p < 0.05). After 18 months, the severity of parkinsonian motor signs "off" medication, levodopa-induced motor complications, and daily levodopa dose were reduced by 69%, 83%, and 57% in operated patients and increased by 29%, 15%, and 12% in the group with medical treatment only (p < 0.001). Adverse events were mild or transient, and overall psychiatric morbidity and anxiety improved in the surgical group.

CONCLUSIONS

Subthalamic nucleus stimulation should be considered a therapeutic option early in the course of Parkinson disease.

Parkinson's disease with camptocormia

BACKGROUND

Camptocormia is defined as an abnormal flexion of the trunk that appears when standing or walking and disappears in the supine position. The origin of the disorder is unknown, but it is usually attributed either to a primary or a secondary paravertebral muscle myopathy or a motor neurone disorder. Camptocormia is also observed in a minority of patients with parkinsonism.

OBJECTIVE

To characterise the clinical and electrophysiological features of camptocormia and parkinsonian symptoms in patients with Parkinson's disease and camptocormia compared with patients with Parkinson's disease without camptocormia.

METHODS

Patients with parkinsonism and camptocormia (excluding patients with multiple system atrophy) prospectively underwent a multidisciplinary clinical (neurological, neuropsychological, psychological, rheumatological) and neurophysiological (electromyogram, ocular movement recording) examination and were compared with age-matched patients with Parkinson's disease without camptocormia.

RESULTS

The camptocormia developed after 8.5 (SD 5.3) years of parkinsonism, responded poorly to levodopa treatment (20%) and displayed features consistent with axial dystonia. Patients with camptocormia were characterised by prominent levodopa-unresponsive axial symptoms (ie, axial rigidity, gait disorder and postural instability), along with a tendency for greater error in the antisaccade paradigm.

CONCLUSION

We suggest that (1) the salient features of parkinsonism observed in patients with camptocormia are likely to represent a specific form of Parkinson's disease and camptocormia is an axial dystonia and (2) both camptocormia and parkinsonism in these patients might result from additional, non-dopaminergic neuronal dysfunction in the basal ganglia.

Motor score of the Unified Parkinson Disease Rating Scale as a good predictor of Lewy body-associated neuronal loss in the substantia nigra

BACKGROUND

How well the motor symptoms assessed by the motor section of the Unified Parkinson Disease Rating Scale (UPDRS3) reflect the neuronal loss observed in the substantia nigra is not known.

OBJECTIVE

To study the relationships among the motor symptoms assessed by the UPDRS3, Lewy body-associated neuronal loss in the substantia nigra, and duration of disease.

DESIGN

Longitudinal, prospective, clinicopathological study.

SETTING

Long-term care facility of a university hospital.

PATIENTS

Eighteen elderly patients with a parkinsonian syndrome, studied prospectively but selected post mortem on the basis of the presence of Lewy bodies, and 5 age-matched control subjects.

METHODS

One map of a section of the substantia nigra, indicating the location of all the nucleolated neuronal profiles, was drawn for each case. Neuronal density was estimated using a tessellation method. The relationship between time and neuronal loss and between neuronal loss and motor symptoms (assessed by the UPDRS3) was studied by means of regression analysis, using linear and exponential models.

RESULTS

The neuronal density was linearly linked with the UPDRS3 score (r = -0.83 [P<.001]). Each point added to the UPDRS3 score corresponded to an estimated loss of 25 neurons/mm(3). The density of neuronal profiles in the substantia nigra decreased exponentially with time (r = -0.73 [P<.001]). Extrapolation of the curve suggested a presymptomatic phase of 5 years.

CONCLUSION

The UPDRS3 score is linearly linked to neuronal density, which, in Lewy body diseases, decreases exponentially with time at a similar pace in this series of elderly patients and in the younger patients described in the literature.

Back problems in Parkinson’s disease: an underestimated problem

STUDY DESIGN

Cross-sectional survey.

OBJECTIVES

To estimate the extent of back pain in Parkinson's disease (PD).

SUMMARY OF BACKGROUND DATA

PD is a common and disabling condition during the course of which back pain may develop. In contrast, the literature on the epidemiology of back pain in PD is poor.

METHODS

Patients with PD, seen consecutively in a neurology clinic over a period of 4 months, were inquired about back pain through a self-questionnaire and compared to an age- and sex-matched control group of chronically ill patients.

RESULTS

The study involved 104 parkinsonians (mean age: 67.3 years) who had had PD for an average of 11.6 years, and 100 controls (mean age: 65.8 years) who had chronic heart disease or diabetes for an average of 14.2 years. Sixty-two parkinsonians and 23 controls reported back pain. The prevalence was 59.6% in the parkinsonian group and 23.0% in the control group (P < 0.0001). Pain severity was evaluated with a visual analogic scale and averaged 54 +/- 23 mm in parkinsonians and 41 +/- 19 mm in control (P < 0.0001).

CONCLUSIONS

Chronic back pain is quite common in PD. It is responsible for a substantial functional impact and needs more attention to reduce disability of such patients.

G2019S LRRK2 mutation in French and North African families with Parkinson's disease

Mutations in LRRK2 were recently identified in autosomal dominant Parkinson's disease (PD), including the G2019S mutation. To evaluate its frequency, we analyzed 198 probands with autosomal dominant PD, mostly from France and North Africa. Surprisingly, the frequency in North African families (7/17, 41%) was greater than those from Europe (5/174, 2.9%). The clinical features in 21 patients, including 1 with a homozygous mutation, were those of typical PD, with lower Mini-Mental State Examination scores. There were also 15 unaffected mutation carriers, aged 32 to 74 years. LRRK2 mutations appear to be a common cause of autosomal dominant PD, particularly in North Africa.

Stimulation of the subthalamic nucleus in Parkinson's disease: a 5 year follow up

BACKGROUND

The short term benefits of bilateral stimulation of the subthalamic nucleus (STN) in patients with advanced levodopa responsive Parkinson's disease (PD) are well documented, but long term benefits are still uncertain.

OBJECTIVES

This study provides a 5 year follow up of PD patients treated with stimulation of the STN.

METHODS

Thirty seven consecutive patients with PD treated with bilateral STN stimulation were assessed prospectively 6, 24, and 60 months after neurosurgery. Parkinsonian motor disability was evaluated with and without levodopa treatment, with and without bilateral STN stimulation. Neuropsychological and mood assessments included the Mattis Dementia Rating Scale, the frontal score, and the Montgomery-Asberg Depression Rating Scale (MADRS).

RESULTS

No severe peri- or immediate postoperative side effects were observed. Six patients died and one was lost to follow up. Five years after neurosurgery: (i) activity of daily living (Unified Parkinson Disease Rating Scale (UPDRS) II) was improved by stimulation of the STN by 40% ("off" drug) and 60% ("on" drug); (ii) parkinsonian motor disability (UPDRS III) was improved by 54% ("off" drug) and 73% ("on" drug); (iii) the severity of levodopa related motor complications was decreased by 67% and the levodopa daily doses were reduced by 58%. The MADRS was unchanged, but cognitive performance declined significantly. Persisting adverse effects included eyelid opening apraxia, weight gain, addiction to levodopa treatment, hypomania and disinhibition, depression, dysarthria, dyskinesias, and apathy.

CONCLUSIONS

Despite moderate motor and cognitive decline, probably due to disease progression, the marked improvement in motor function observed postoperatively was sustained 5 years after neurosurgery.

Bilateral deep brain stimulation in Parkinson's disease: a multicentre study with 4 years follow-up

Deep brain stimulation (DBS) is associated with significant improvement of motor complications in patients with severe Parkinson's disease after some 6-12 months of treatment. Long-term results in a large number of patients have been reported only from a single study centre. We report 69 Parkinson's disease patients treated with bilateral DBS of the subthalamic nucleus (STN, n = 49) or globus pallidus internus (GPi, n = 20) included in a multicentre study. Patients were assessed preoperatively and at 1 year and 3-4 years after surgery. The primary outcome measure was the change in the 'off' medication score of the Unified Parkinson's Disease Rating Scale motor part (UPDRS-III) at 3-4 years. Stimulation of the STN or GPi induced a significant improvement (50 and 39%; P < 0.0001) of the 'off' medication UPDRS-III score at 3-4 years with respect to baseline. Stimulation improved cardinal features and activities of daily living (ADL) (P < 0.0001 and P < 0.02 for STN and GPi, respectively) and prolonged the 'on' time spent with good mobility without dyskinesias (P < 0.00001). Daily dosage of levodopa was significantly reduced (35%) in the STN-treated group only (P < 0.001). Comparison of the improvement induced by stimulation at 1 year with 3-4 years showed a significant worsening in the 'on' medication motor states of the UPDRS-III, ADL and gait in both STN and GPi groups, and speech and postural stability in the STN-treated group. Adverse events (AEs) included cognitive decline, speech difficulty, instability, gait disorders and depression. These were more common in patients treated with DBS of the STN. No patient abandoned treatment as a result of these side effects. This experience, which represents the first multicentre study assessing the long-term efficacy of either STN or GPi stimulation, shows a significant and substantial clinically important therapeutic benefit for at least 3-4 years in a large cohort of patients with severe Parkinson's disease.

Parkinson disease, brain volumes, and subthalamic nucleus stimulation

BACKGROUND

High-frequency stimulation of the subthalamic nucleus (STN) is an effective treatment for advanced Parkinson disease (PD). The clinical and preoperative predictive factors of the best postoperative outcome have been identified. Radiologic predictive factors were investigated.

METHODS

Forty patients with PD underwent surgery for bilateral STN stimulation. MRI was performed in stereotactic conditions before surgery. Brain parenchyma, caudate nucleus, putamen, pallidum, and red nucleus volumes and the surface of the mesencephalon were measured and normalized as percentages of the intracranial volume. Clinical evaluation was performed 1 month before and 6 months after surgery.

RESULTS

The normalized brain parenchyma volume was lower in patients who were older and had a longer disease duration or a lower frontal score and was not predictive of the postoperative outcome. The residual scores for activities of daily living and parkinsonian motor disability were higher in patients with a smaller normalized mesencephalon. The normalized caudate nucleus volume was predictive of the pre- and postoperative levodopa-equivalent dosage.

CONCLUSIONS

Brain atrophy is not an exclusion criterion for neurosurgery, indicating that patients' neurologic, psychiatric, and neuropsychological characteristics are the best predictive factors for neurosurgery. The fact that a smaller normalized mesencephalon surface was associated with a lower beneficial effect of the subthalamic nucleus stimulation on the parkinsonian motor disability suggests that the normalized mesencephalon surface is a predictive factor of the postoperative outcome.

Neurokinin B, Neurotensin, and Cannabinoid Receptor Antagonists and Parkinson Disease

The neuropeptides neurokinin B, neurotensin, and anandamide, the endogenous ligands of NK3, NT1, and CB1 receptors respectively, are known to interact with brain dopaminergic transmission. This study evaluated the effects of these three antagonists of the NK3 (SR 142801), neurotensin (SR 48692), and cannabinoid (SR 141716) receptors on the severity of motor symptoms and levodopa-induced dyskinesias after administration of a single dose of levodopa in 24 patients with Parkinson disease. In this exploratory randomized, double-blind, placebo-controlled study, at the dose used, the drugs tested were well tolerated and could not improve parkinsonian motor disability.

Subthalamic stimulation in Parkinson disease: with or without anesthesia?

OBJECTIVE

To study the effects of general anesthesia on the postoperative outcome of patients with Parkinson disease (PD) who underwent surgery using bilateral placement of stimulating electrodes within the subthalamic nucleus (STN).

DESIGN

Retrospective analysis.

SETTING

Hôpital de la Salpêtrière, Paris, France.

PATIENTS

Fifteen PD patients who underwent bilateral implantation of electrodes within the STN received general anesthesia because of severe anxiety, poorly tolerated off-period dystonia, or respiratory difficulties. These patients were compared with 15 patients matched for age, disease duration, and parkinsonian motor disability who underwent the same neurosurgical procedure under local anesthesia.

MAIN OUTCOME MEASURE

Motor disability scores.

RESULTS

After surgery, the severity of parkinsonian motor disability was markedly improved in both groups of patients. Compared with patients who were under local anesthesia during the operation, the residual parkinsonian motor score under stimulation (with ["on"] or without ["off"] levodopa) and the intensity of stimulation were higher in patients who were under general anesthesia during the operation.

CONCLUSIONS

Although the improvement of parkinsonian motor disability is greater in PD patients who receive local anesthesia during surgery, general anesthesia can be performed in patients unable to tolerate prolonged states without levodopa.

Effects of High-Frequency Stimulation on Subthalamic Neuronal Activity in Parkinsonian Patients

BACKGROUND

High-frequency stimulation of the subthalamic nucleus (STN) is a neurosurgical alternative to medical treatment in levodopa-responsive forms of Parkinson disease. The mechanism of action of STN stimulation remains controversial, although an inhibition of overactive STN neurons has been postulated.

OBJECTIVE

To determine the effects of high-frequency STN stimulation on the neuronal activity of STN neurons in Parkinson disease patients.

PATIENTS

Single-unit recordings of the neuronal activity of the STN were obtained before, during, and after the application of intra-STN electrical stimulation in 15 Parkinson disease patients. Changes in firing frequency and pattern were analyzed using various combinations of stimulus frequency (range, 14-140 Hz).

RESULTS

Stimulation at a frequency greater than 40 Hz applied within the STN significantly decreased the firing frequency and increased the burst-like activity in the firing pattern of STN neurons. An aftereffect was observed in cells that had been totally inhibited during high-frequency stimulation.

CONCLUSION

The beneficial effects of high-frequency stimulation result from a change in the firing pattern of cellular discharge and a blockade of the spontaneous overactivity of STN neurons.

Parkinson's disease, subthalamic stimulation, and selection of candidates: A pathological study

We report on a patient with Parkinson's disease (PD) who was moderately improved by stimulation of the subthalamic nucleus (STN) and died 2 years after electrode implantation. After neurosurgery, symptoms that had responded to levodopa treatment preoperatively continued to improve. Postural instability, dysarthria, and cognitive impairment continued to worsen, despite STN stimulation and levodopa treatment. Postmortem examination of the brain confirmed the diagnosis of PD and showed that the electrodes had been correctly positioned within the STN. The failure of STN stimulation in this patient confirms the importance of screening and excluding patients from surgery with evolving parkinsonian axial symptoms or cognitive impairment.

Coding polymorphisms in the parkin gene and susceptibility to Parkinson disease

BACKGROUND

Mutations in the parkin gene, an E3 protein-ubiquitin ligase, cause autosomal recessive early-onset Parkinson disease (PD). The role of polymorphisms in the parkin gene as risk factors for PD is still unclear, as the results in the literature are contradictory.

PATIENTS

We compared the allele and genotype frequencies of the Ser167Asn, Arg366Trp, Val380Leu, and Asp394Asn polymorphisms in 194 patients with PD (92 familial and 102 sporadic) and 125 control subjects.

RESULTS

Homozygous Val380 was significantly associated with sporadic PD (P =.008). There was also a trend toward an association of homozygous Asp394 with familial PD (P =.07).

CONCLUSIONS

Some parkin polymorphisms appear to be risk factors for sporadic or familial PD. The functional effects of these coding polymorphisms need to be established, and further studies on parkin polymorphisms in PD should be undertaken.

How much phenotypic variation can be attributed to parkin genotype?

To establish phenotype-genotype correlations in early-onset parkinsonism, we have compared the phenotype of a large series of 146 patients with and 250 patients without parkin mutations. Although no single sign distinguished the groups, patients with mutations had significantly earlier and more symmetrical onset, dystonia more often at onset and hyperreflexia, slower progression of the disease, and a tendency toward a greater response to levodopa despite lower doses. After forward stepwise multiple logistic regression analysis, dystonia at onset and brisk reflexes were not longer significantly different but were correlated with age at onset rather than the presence of the parkin mutation. Age at onset in carriers of parkin mutations varied as did the rate of progression of the disease: the younger the age at onset the slower the evolution. The genotype influenced the phenotype: carriers of at least one missense mutation had a higher United Parkinson's Disease Rating Scale motor score than those carrying two truncating mutations. The localization of the mutations was also important because missense mutations in functional domains of parkin resulted in earlier onset. Patients with a single heterozygous mutation had significantly later and more asymmetrical onset and more frequent levodopa-induced fluctuations and dystonia than patients with two mutations.

Subthalamic stimulation in Parkinson disease: intraoperative predictive factors

BACKGROUND

High-frequency stimulation of the subthalamic nucleus (STN) is an effective treatment for advanced forms of Parkinson disease. Postoperative improvement of motor parkinsonian disability is known to depend on patient selection and surgical targeting.

OBJECTIVE

To determine which clinical and electrophysiological variables evaluated during the operation predict the postoperative clinical outcome of patients with Parkinson disease treated by bilateral high-frequency stimulation of the STN.

METHODS

Intraoperative clinical and electrophysiological data obtained in 41 patients with Parkinson disease who underwent bilateral implantation of electrodes for STN stimulation were correlated with the improvement in parkinsonian disability assessed 6 months after the operation.

RESULTS

The extent of STN neuronal activity recorded along the trajectory of the therapeutic electrode had no effect on the postoperative clinical outcome. The intraoperative improvement in segmental akinesia, but not rigidity, was predictive of the postoperative improvement in parkinsonian motor disability and reduction in daily levodopa-equivalent dosage. Parkinsonian motor disability scores assessed after surgery were lower in patients with intraoperative stimulation-induced dyskinesias than in those without stimulation-induced dyskinesias.

CONCLUSION

The improvement of segmental akinesia and the observation of dyskinesias provoked by stimulation during the operation predict the best postoperative effects of bilateral STN stimulation on parkinsonian motor disability.

Tactile hallucinations in Parkinson's disease

Hallucinations occur in up to 40% of patients with Parkinson's disease (PD) and are mainly of a visual nature. We prospectively studied 8 patients with PD and tactile hallucinations (TH). TH occurred with a clear sensorium, and were long-lasting. In most cases they involved animals, were combined with other types of hallucinations occurring simultaneously (mainly formed visual hallucinations), and predominated in the evening and/or at night. Pharmacological and disease-related factors, including a disorder in rapid-eye-movement sleep mechanisms, could play a part in the pathophysiology of these hallucinations.

Aggressive behavior induced by intraoperative stimulation in the triangle of Sano

The authors report a patient with advanced PD, successfully treated by bilateral stimulation of the subthalamic nucleus, who developed acute transient aggressive behavior during intraoperative electrical test stimulation. The electrode responsible for this abnormal behavior was located within the lateral part of the posteromedial hypothalamic region (triangle of Sano). The authors suggest that affect can be dramatically modulated by the selective manipulation of deep brain structures.

Compulsions, Parkinson's disease, and stimulation

Pathophysiological models suggest that obsessive compulsive disorder (OCD) might be associated with dysfunctions in cortico-striato-pallido-thalamo-cortical neuronal circuits. We implanted subthalamic electrodes to alleviate parkinsonian symptoms in two patients who had Parkinson's disease and a history of severe OCD. Parkinsonian disability improved postoperatively in both patients, and 2 weeks after the procedure, their compulsions had disappeared and obsessive symptoms improved (58% improvement for patient 1 on the Yale-Brown obsessive compulsive scale, 64% for patient 2). The improvements in these two patients suggest that high-frequency stimulation could improve function in the subcortical-limbic circuitry in patients with severe OCD.

Association study between iron-related genes polymorphisms and Parkinson's disease

We have conducted a case-control study in order to test for an association between 8 intragenic polymorphisms of 5 iron-related genes (transferrin, transferrin receptor1, HFE, frataxin and lactoferrin) and Parkinson disease. Comparison of genotypes and allele frequencies did not differ significantly between cases and controls for all studied polymorphisms except the G258S transferrin polymorphism, for which a higher frequency of the G allele was found among cases (p=0.033), particularly among cases with onset older than 60 (p=0.0017) and with negative family history (p=0.022). This finding suggests that genetic variations in the control of iron metabolism may contribute to the pathogenesis of the disease.

[Pergolide: a useful agonist for the treatment of Parkinson disease]

The efficiency of pergolide has been confirmed by the study of a group 29 parkinsonian patients. They were relatively young, and the duration of evolution of their Parkinson's disease was more then ten years, with levodopa-induced dyskinesia and fluctuations. In this group of patients with most serious motor disability, it has been possible to improve dyskinesia and fluctuations with a relatively important dosage of pergolide and without increase of levodopa dosage.

Behavioural disorders, Parkinson's disease and subthalamic stimulation

OBJECTIVE

to analyse 24 parkinsonian patients successfully treated by bilateral STN stimulation for the presence of behavioural disorders.

METHOD

patients were evaluated retrospectively for adjustment disorders (social adjustment scale, SAS), psychiatric disorders (comparison of the results of psychiatric interview and the mini international neuropsychiatric inventory) and personality changes (IOWA scale of personality changes).

RESULTS

parkinsonian motor disability was improved by 69.5% and the levodopa equivalent daily dosage was reduced by 60.5%. Social adjustment (SAS) was considered good or excellent in nine patients, moderately (n=14), or severely (n=1) impaired in 15 patients. Psychiatric disorders consisted of amplification or decompensation of previously existing disorders that had sometimes passed unnoticed, such as depressive episodes (n=4), generalised anxiety (n=18), and behavioural disorders with drug dependence (n=2). Appearance of mild to moderate emotional hyperreactivity was reported in 15 patients. Personality traits (IOWA scale) were improved in eight patients, unchanged in seven, and aggravated in eight

CONCLUSION

Improvement in parkinsonian motor disability induced by STN stimulation is not necessarily accompanied by improvement in psychic function and quality of life. Attention is drawn to the possible appearance of personality disorders and decompensation of previous psychiatric disorders in parkinsonian patients who are suitable candidates for neurosurgery. We suggest that a careful psychological and psychiatric interview be performed before surgery, and emphasise the need for psychological follow up to ensure the best possible outcome.

Clinical predictive factors of subthalamic stimulation in Parkinson's disease

High-frequency stimulation of the subthalamic nucleus (STN) constitutes one of the most effective treatments for advanced forms of Parkinson's disease. The cost and potential risks of this procedure encourage the determination of clinical characteristics of patients that will have the best postoperative outcome. Forty-one Parkinson's disease patients underwent surgery for bilateral STN stimulation. The selection criteria were severe parkinsonian motor disability, clear response of symptoms to levodopa, occurrence of disabling levodopa-related motor complications and the absence of dementia and significant abnormalities on brain MRI. Clinical evaluation was performed 1 month before and 6 months after surgery. The improvement in the activities of daily living subscale of the Unified Parkinson's Disease Rating Scale, Part II (UPDRS II) and parkinsonian motor disability (UPDRS III) was greater when the preoperative scores for activities of daily living and parkinsonian motor disability, in particular axial symptoms, such as gait disorders and postural instability assessed at the time of maximal clinical improvement (on drug), were lower. Age and disease duration were not predictive, but parkinsonian motor disability tended to be more improved in patients with younger age and shorter disease duration. The severity of levodopa-related motor complications was not a predictive factor. The outcome of STN stimulation was excellent in levodopa-responsive forms of Parkinson's disease, i.e. in patients with selective brain dopaminergic lesions, and moderate in patients with axial motor symptoms and cognitive impairment known to be less responsive or unresponsive to levodopa treatment, i.e. when brain non-dopaminergic lesions develop in addition to the degeneration of the nigrostriatal dopaminergic system. The results are consistent with the classical inclusion criteria for STN stimulation, but imply that the decision to operate on the oldest patients and/or patients with gait and postural disorders, who are poorly responsive to levodopa, should be weighed carefully.

Idazoxan, an alpha-2 antagonist, and L-DOPA-induced dyskinesias in patients with Parkinson's disease

Dyskinesia is a frequent and disabling side effect in patients with Parkinson's disease treated with chronic dopa-therapy. Preclinical data in the 1-methyl-4-phenyl-1,2,3,6,-tetrahydropyridine (MPTP) monkey suggest that alpha-2 antagonists may reduce dihydroxyphenylalanine (L-DOPA)-induced dyskinesia. We assessed, in a pilot randomised placebo-controlled study, the effects of single oral doses (10 mg, 20 mg, and 40 mg) of idazoxan, an alpha-2 antagonist, on motor parkinsonian disability and L-DOPA-induced dyskinesia following an acute oral challenge of L-DOPA in 18 patients with Parkinson's disease. The severity of L-DOPA-induced dyskinesia improved after 20 mg idazoxan pretreatment, while there was no concommittant deterioration in the antiparkinsonian response to L-DOPA. These results suggest that blocking alpha-2 receptors in patients with Parkinson's disease might improve L-DOPA-induced dyskinesia without the cost of a return of parkinsonian symptomatology. Further studies are required to assess whether this property could have potential therapeutic applications in the long-term management of dyskinetic patients with Parkinson's disease.

[Rating scales for Parkinson's disease: when and how to use them]

In Parkinson's disease, rating scales are used to assess the degree of disease-related disability and to titrate treatment to each phase of the disease course. Clinicians should be widely aware of these scales and know how to use them. The UPDRS is the most widely used, having proven intra- and inter-observer validity. The purely motor items of the UPDRS allow an evaluation of response to dopaminergic treatment. Scales including all aspects of the disease, motor, cognitive and psychiatric impairment, can also be used. Some of the simple scales can be used at consultation or the patientis bedside, others require experience in psychological care. They are useful in daily practice for patient follow-up and facilitate communication between caregivers. Quality of life scales have been developed more recently. These scales take into account the patientis own perception of his/her disability and its impact on daily activities. Finally, motor and cognitive disability scales are used in clinical research protocols.