Genetics of Parkinson's disease in Brazil: a systematic review of monogenic forms

BACKGROUND

Increasing numbers of mutations causing monogenic forms of Parkinson's disease (PD) have been described, mostly among patients in Europe and North America. Since genetic architecture varies between different populations, studying the specific genetic profile of Brazilian patients is essential for improving genetic counseling and for selecting patients for clinical trials.

OBJECTIVE

We conducted a systematic review to identify genetic studies on Brazilian patients and to set a background for future studies on monogenic forms of PD in Brazil.

METHODS

We searched MEDLINE, EMBASE and Web of Science from inception to December 2019 using terms for "Parkinson's disease", "genetics" and "Brazil". Two independent reviewers extracted the data. For the genes LRRK2 and PRKN, the estimated prevalence was calculated for each study, and a meta-analysis was performed.

RESULTS

A total of 32 studies were included, comprising 94 Brazilian patients with PD with a causative mutation, identified from among 2,872 screened patients (3.2%). PRKN mutations were causative of PD in 48 patients out of 576 (8.3%). LRRK2 mutations were identified in 40 out of 1,556 patients (2.5%), and p.G2019S was the most common mutation (2.2%).

CONCLUSIONS

PRKN is the most common autosomal recessive cause of PD, and LRRK2 is the most common autosomal dominant form. We observed that there was a lack of robust epidemiological studies on PD genetics in Brazil and, especially, that the diversity of Brazil's population had not been considered.

Use of non-invasive stimulation in movement disorders: a critical review

BACKGROUND

Noninvasive stimulation has been widely used in the past 30 years to study and treat a large number of neurological diseases, including movement disorders.

OBJECTIVE

In this critical review, we illustrate the rationale for use of these techniques in movement disorders and summarize the best medical evidence based on the main clinical trials performed to date.

METHODS

A nationally representative group of experts performed a comprehensive review of the literature in order to analyze the key clinical decision-making factors driving transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS) in movement disorders. Classes of evidence and recommendations were described for each disease.

RESULTS

Despite unavoidable heterogeneities and low effect size, TMS is likely to be effective for treating motor symptoms and depression in Parkinson's disease (PD). The efficacy in other movement disorders is unclear. TMS is possibly effective for focal hand dystonia, essential tremor and cerebellar ataxia. Additionally, it is likely to be ineffective in reducing tics in Tourette syndrome. Lastly, tDCS is likely to be effective in improving gait in PD.

CONCLUSIONS

There is encouraging evidence for the use of noninvasive stimulation on a subset of symptoms in selected movement disorders, although the means to optimize protocols for improving positive outcomes in routine clinical practice remain undetermined. Similarly, the best stimulation paradigms and responder profile need to be investigated in large clinical trials with established therapeutic and assessment paradigms that could also allow genuine long-term benefits to be determined.

Transcutaneous tibial nerve home stimulation for overactive bladder in women with Parkinson's disease: A randomized clinical trial

AIMS

This study aims to investigate the efficacy of transcutaneous tibial nerve home stimulation for overactive bladder (OAB) in women with Parkinson's disease (PD).

METHODS

The current study is a prospective, randomized, double-blind, sham-controlled trial. Home intervention was carried out and assessments were conducted at a tertiary hospital in South Brazil. Women with PD and OAB symptoms were included in the study. Patients were randomly divided into two groups: (1) stimulation and (2) sham. Both groups underwent intervention at home for 12 weeks. Patients were evaluated at baseline and at 12 weeks (end of intervention), 30- and 90-day follow-up. The primary outcome was the mean reduction in the number of urgency incontinence episodes, and secondary outcomes included daytime and nighttime urinary frequency, urinary urgency episodes, use of pad (reported in a 24-h bladder diary), OAB-V8 and King's Health Questionnaire scores, and maintenance of symptom relief after discontinuation of the intervention.

RESULTS

In total, 30 consecutive patients completed the study (15/group). The stimulation group showed a reduction in nighttime urinary frequency (0.9 ± 0.6), urinary urgency (1.0 ± 1.2), urgency incontinence episodes (0.5 ± 0.6), use of pads (1.3 ± 1.2), and OAB-V8 (1.3 ± 1.2) and King's Health Questionnaire scores. In a 30-day and 90-day follow-up, 8 (53.3%) and 5 (33.3%) stimulation patients, respectively, reported full maintenance of symptom relief after discontinuation of the intervention. Stimulation patients presented a statistically significant improvement of symptoms as compared with sham patients (p = .001).

CONCLUSIONS

Transcutaneous tibial nerve home stimulation can be used in clinical practice as an effective nonpharmacological resource for the reduction of OAB symptoms in women with PD, and the resulting relief seems to persist in the follow-up (30 and 90 days).

Nordic Walking and Free Walking Improve the Quality of Life, Cognitive Function, and Depressive Symptoms in Individuals with Parkinson's Disease: A Randomized Clinical Trial

Nordic walking's (NW) degree of effectiveness regarding health-related parameters in people with Parkinson's Disease (PD) is a subject of debate. While NW seems to improve functionality, a clear non-motor benefit has not been demonstrated. The aim of this randomized controlled trial was to compare the effects of 9-week NW and free walking (FW) training programs on quality of life, cognitive function, and depressive symptoms in individuals with PD. Thirty-three people with PD, (Hoehn and Yahr 1-4) were randomized into two groups: NW (n = 16) and FW (n = 17). We analyzed quality of life, cognitive function, depressive symptoms, and motor symptoms. Significant improvements were found in the overall, physical, psychological, social participation, and intimacy domains of quality of life, as well as in cognitive function and depressive symptoms for both groups. Only the NW group showed improvement in the autonomy domain. Individuals with PD had a similar enhancement of non-motor symptoms after walking training, with or without poles. However, the NW group showed a more significant improvement in the autonomy domain, strengthening the applied and clinical potential of NW in people with PD. Future studies are needed to determine the efficacy of walking training without poles in subjects with PD.

Plantar stimulation alters brain connectivity in idiopathic Parkinson's disease

OBJECTIVE

Individuals with Parkinson's disease (PD) and freezing of gait (FOG) present peripheral and central sensitivity disturbances that impair motor performance. This study aimed to investigate long-term effects of plantar sensory stimulation on brain activity, brain connectivity, and gait velocity of individuals with PD and FOG.

METHODS

Twenty-five participants were enrolled in this clinical trial (NCT02594540). Plantar sensory stimulation was delivered using the Automated Mechanical Peripheral Stimulation therapy (AMPS). Volunteers were randomly assigned to real or placebo AMPS groups and received eight sessions of treatment. The primary outcome was brain activity (task-based fMRI-active ankle dorsi-plantar flexion). Secondary outcomes were brain connectivity (resting state-RS fMRI) and gait velocity. fMRI was investigated on the left, right, and mid-sensory motor regions, left and right basal ganglia.

RESULTS

No changes in brain activity were observed when task-based fMRI was analyzed. After real AMPS, RS functional connectivity between basal ganglia and sensory-related brain areas increased (insular and somatosensory cortices). Gait velocity also increased after real AMPS. A positive correlation was found between gait velocity and the increased connectivity between sensory, motor and supplementary motor cortices.

CONCLUSION

Plantar sensory stimulation through AMPS was not able to modify brain activity. AMPS increased the RS brain connectivity mainly in areas related to sensory processing and sensorimotor integration. Plantar stimulation could be a way to improve plantar sensitivity and consequently ameliorate gait performance. However, the mechanisms behind the way AMPS influences brain pathways are still not completely known.

Diagnostic prediction model for levodopa-induced dyskinesia in Parkinson's disease

BACKGROUND

There are currently no methods to predict the development of levodopa-induced dyskinesia (LID), a frequent complication of Parkinson's disease (PD) treatment. Clinical predictors and single nucleotide polymorphisms (SNP) have been associated to LID in PD.

OBJECTIVE

To investigate the association of clinical and genetic variables with LID and to develop a diagnostic prediction model for LID in PD.

METHODS

We studied 430 PD patients using levodopa. The presence of LID was defined as an MDS-UPDRS Part IV score ≥1 on item 4.1. We tested the association between specific clinical variables and seven SNPs and the development of LID, using logistic regression models.

RESULTS

Regarding clinical variables, age of PD onset, disease duration, initial motor symptom and use of dopaminergic agonists were associated to LID. Only CC genotype of ADORA2A rs2298383 SNP was associated to LID after adjustment. We developed two diagnostic prediction models with reasonable accuracy, but we suggest that the clinical prediction model be used. This prediction model has an area under the curve of 0.817 (95% confidence interval [95%CI] 0.77‒0.85) and no significant lack of fit (Hosmer-Lemeshow goodness-of-fit test p=0.61).

CONCLUSION

Predicted probability of LID can be estimated with reasonable accuracy using a diagnostic clinical prediction model which combines age of PD onset, disease duration, initial motor symptom and use of dopaminergic agonists.

Dysphonia and Dysarthria in People With Parkinson's Disease After Subthalamic Nucleus Deep Brain Stimulation: Effect of Frequency Modulation

PURPOSE

Subthalamic nucleus deep brain stimulation (STN-DBS) parameters, for example the frequency of stimulation, seem to affect speech and voice aspects. However, this influence is not well understood. This study aimed to investigate the impact of low- and high-frequency STN-DBS on voice and speech for people with Parkinson's disease.

METHODS

Nineteen individuals with Parkinson's disease who received bilateral STN-DBS were assessed for motor performance (Unified Parkinson's Disease Rating Scale-III), perceptual evaluation of voice (grade, roughness, breathiness, asthenia, strain, and instability [GRBASI]), dysarthria assessment, and computerized acoustic analysis of voice upon receiving low-frequency (60 Hz) and high-frequency (130 Hz) STN-DBS.

RESULTS

In the GRBASI protocol, asthenia, and instability were significantly better at 130 Hz of stimulation. In the dysarthria evaluation, the phonation aspect, articulation, and grade of dysarthria showed deterioration at the same high-frequency condition. There was no significant difference for any vocal acoustic measures.

CONCLUSION

The high-frequency of STN-DBS may affect speech and voice differently, leading to an amelioration of the vocal production, but with adverse effects in the speech control.

Cortisol levels, motor, cognitive and behavioral symptoms in Parkinson's disease: a systematic review

Parkinson's disease (PD) is a progressive and multifactorial neurodegenerative disease. It has been suggested that a dysregulation of the hypothalamic-pituitary-adrenal axis (HPA) occurs in PD. Furthermore, this dysregulation may be involved in triggering, exacerbation or progression of disease. The objective of this study was to systematically review the literature regarding cortisol levels and their relation with motor, cognitive and behavioral symptoms in patients with PD. A systematic search was performed in PubMed and Embase databases, according to PRISMA norms. Twenty-one studies were included, which evaluated baseline levels of cortisol and motor, cognitive, behavioral symptoms, drugs administration or deep brain stimulation to PD treatment. Sample size ranged from 7 to 249 individuals. In 14 studies that assessed cortisol levels in PD patients, seven showed elevation of cortisol levels. In relation to symptomatology, high levels of cortisol were associated with worst functional scores evaluated by UPDRS, depression and behavior in risk preference. Medication interactions showed an influence on the regulation of cortisol release, mainly, conventional drugs used in the PD's treatment, such as levodopa. The results found in this review point to a possible relationship between cortisol levels and symptoms in PD, indicating that an HPA axis dysfunction related to cortisol level occurs in PD.

Plantar stimulation in parkinsonians: From biomarkers to mobility - randomized-controlled trial

BACKGROUND

The decrease of Brain-Derived Neurotrophic Factor (BDNF) serum levels has been related to the pathophysiology of several neurodegenerative diseases as well as to neural plasticity and rehabilitation. Automated Mechanical Peripheral Stimulation (AMPS) has been investigated as a complementary therapy for Parkinson Disease (PD).

OBJECTIVES

(1) to investigate the effects of AMPS on BDNF and Cortisol serum levels of subjects with PD; (2) to evidence the interplay between BDNF and Cortisol serum levels and the functional mobility improvement after AMPS treatment.

METHODS

Thirty-three subjects with PD were randomized into two groups: effective stimulation (AMPS, n = 16) or placebo stimulation (AMPS SHAM, n = 17). Fourteen healthy aged-matched subjects were included as a reference group. Each AMPS group received eight sessions of treatment using a commercial medical device (Gondola™). BDNF and Cortisol serum levels, spatiotemporal gait parameters and TUG test were assessed at baseline and after eight sessions of treatment.

RESULTS

After the treatment, AMPS group showed significantly higher levels of BDNF and lower levels of Cortisol compared to AMPS SHAM. AMPS group also showed a positive effect on gait pattern as a higher improvement on gait velocity, stride length, and TUG performance was shown.

CONCLUSION

Effective AMPS treatment increased BDNF and decreased Cortisol serum levels and produced improvements in functional mobility.

Erratum: Variable frequency of LRRK2 variants in the Latin American research consortium on the genetics of Parkinson's disease (LARGE-PD), a case of ancestry

[This corrects the article DOI: 10.1038/s41531-017-0020-6.].

Different outcomes of phonemic verbal fluency in Parkinson's disease patients with subthalamic nucleus deep brain stimulation

Subthalamic nucleus deep brain stimulation (STN-DBS) is a surgical technique to treat motor symptoms in patients with Parkinson's disease (PD). Studies have shown that STN-DBS may cause a decline in verbal fluency performance. We aimed to verify the effects of STN-DBS on the performance of phonemic verbal fluency in Brazilian PD patients. Sixteen participants were evaluated on the Unified Parkinson's Disease Rating Scale - Part III and for phonemic fluency ("FAS" version) in the conditions of on- and off-stimulation. We identified two different patterns of phonemic verbal fluency outcomes. The results indicate that there may be no expected pattern of effect of bilateral STN-DBS in the phonemic fluency, and patients may present with different outcomes for some reason not well understood.

Benefit from the Chin-Down Maneuver in the Swallowing Performance and Self-Perception of Parkinson's Disease Patients

Aims. To verify the effectiveness of the maneuver application in swallowing therapy with PD. Materials and Method. We performed an open-label trial, with three groups compounds by PD individuals: the experimental group, control group, and orientation group. The study included PD patients with dysphagia. A cognitive screening, through a questionnaire about depression and quality of life, was conducted. Swallowing assessment was performed through (1) fiberoptic endoscopic evaluation of swallowing (FEES); (2) clinical evaluation and Functional Oral Intake Scale (FOIS); and (3) assessment of the quality life related to swallowing (SWALQOL). A therapeutic program, which consisted of chin-down postural maneuver and orientations on feeding, was applied. Both groups (EG and OG) received on-month therapeutic program. Results. A significant improvement in swallowing, evaluated by clinical assessment, was observed in solid (p < 0.001) and liquid (p = 0.022) consistencies in EG when compared to OG and CG. Patients in EG presented improvement in QoL, with the significant difference in comparison with the other groups, about domain frequency of symptoms (p = 0.029) in SWALQOL questionnaire. Conclusion. The postural maneuver chin-down improved swallowing performance and self-perception, but not the laryngeal signs. This trial is registered with registration number NCT02973698.

Deep Brain Stimulation Frequency of the Subthalamic Nucleus Affects Phonemic and Action Fluency in Parkinson's Disease

Introduction. Deep brain stimulation of the subthalamic nucleus (STN-DBS) in Parkinson's disease (PD) has been linked to a decline in verbal fluency. The decline can be attributed to surgical effects, but the relative contributions of the stimulation parameters are not well understood. This study aimed to investigate the impact of the frequency of STN-DBS on the performance of verbal fluency tasks in patients with PD. Methods. Twenty individuals with PD who received bilateral STN-DBS were evaluated. Their performances of verbal fluency tasks (semantic, phonemic, action, and unconstrained fluencies) upon receiving low-frequency (60 Hz) and high-frequency (130 Hz) STN-DBS were assessed. Results. The performances of phonemic and action fluencies were significantly different between low- and high-frequency STN-DBS. Patients showed a decrease in these verbal fluencies for high-frequency STN-DBS. Conclusion. Low-frequency STN-DBS may be less harmful to the verbal fluency of PD patients.

Postural instability and falls are more frequent in Parkinson’s disease patients with worse trunk mobility

ABSTRACT Postural instability and axial rigidity are frequent symptoms of the Parkinson’s disease (PD). Objective Correlate the occurrence of falls and the activity of rolling over in bed with performance on the Trunk Mobility Scale (TMS) in patients with PD, and determine whether this instrument score can predict the risk of falls. Method This is a cross-sectional study. Assessed patients reported the frequency of falls in the previous year and whether they had difficulties rolling over in bed. Then, the following scales were applied: TMS, Hoehn and Yahr, Unified Parkinson’s Disease Rating Scale-III and Schwab and England Activities of Daily Living. Results Eighty-five patients were analyzed. Patients with a history of falling showed worse performance in the TMS (p < 0.01). There is a significant correlation between TMS and the activity of rolling over in bed (p < 0.01). Conclusion PD fallers present worse scores in TMS, and there is a significant correlation between difficulty rolling over in bed and TMS score.

Influence of genetic, biological and pharmacological factors on levodopa dose in Parkinson's disease

AIM

Levodopa is first-line treatment of Parkinson's disease motor symptoms but, dose response is highly variable. Therefore, the aim of this study was to determine how much levodopa dose could be explained by biological, pharmacological and genetic factors.

PATIENTS & METHODS

A total of 224 Parkinson's disease patients were genotyped for SV2C and SLC6A3 polymorphisms by allelic discrimination assays. Comedication, demographic and clinical data were also assessed.

RESULTS

All variables with p < 0.20 were included in a multiple regression analysis for dose prediction. The final model explained 23% of dose variation (F = 11.54; p < 0.000001).

CONCLUSION

Although a good prediction model was obtained, it still needs to be tested in an independent sample to be validated.

Iron and Oxidative Stress in Parkinson's Disease: An Observational Study of Injury Biomarkers

Parkinson's disease (PD) is characterized by progressive motor impairment attributed to progressive loss of dopaminergic neurons in the substantia nigra (SN) pars compacta. In addition to an accumulation of iron, there is also an increased production of reactive oxygen/nitrogen species (ROS/RNS) and inflammatory markers. These observations suggest that iron dyshomeostasis may be playing a key role in neurodegeneration. However, the mechanisms underlying this metal-associated oxidative stress and neuronal damage have not been fully elucidated. To determine peripheral levels of iron, ferritin, and transferrin in PD patients and its possible relation with oxidative/nitrosative parameters, whilst attempting to identify a profile of peripheral biomarkers in this neurological condition. Forty PD patients and 46 controls were recruited to compare serum levels of iron, ferritin, transferrin, oxidative stress markers (superoxide dismutase (SOD), catalase (CAT), nitrosative stress marker (NOx), thiobarbituric acid reactive substances (TBARS), non-protein thiols (NPSH), advanced oxidation protein products (AOPP), ferric reducing ability of plasma (FRAP) and vitamin C) as well as inflammatory markers (NTPDases, ecto-5’-nucleotidase, adenosine deaminase (ADA), ischemic-modified albumin (IMA) and myeloperoxidase). Iron levels were lower in PD patients, whereas there was no difference in ferritin and transferrin. Oxidative stress (TBARS and AOPP) and inflammatory markers (NTPDases, IMA, and myeloperoxidase) were significantly higher in PD, while antioxidants FRAP, vitamin C, and non-protein thiols were significantly lower in PD. The enzymes SOD, CAT, and ecto-5’-nucleotidase were not different among the groups, although NOx and ADA levels were significantly higher in the controls. Our data corroborate the idea that ROS/RNS production and neuroinflammation may dysregulate iron homeostasis and collaborate to reduce the periphery levels of this ion, contributing to alterations observed in the pathophysiology of PD.

Planning future clinical trials in Machado Joseph disease: Lessons from a phase 2 trial

BACKGROUND

In a recent phase 2 clinical trial in spinocerebellar ataxia type 3/Machado Joseph disease (SCA3/MJD), a neurogenetic disorder without specific therapy, benefits of lithium carbonate were found only on secondary efficacy outcomes, all related to ataxic features. In order to help designing future studies, we further analyzed the trial data searching for treatment response modifiers and metric properties of spinocerebellar ataxia (SCA) scales.

METHODS

Efficacy analysis was performed with the Neurological Examination Score for the Assessment of Spinocerebellar Ataxia (NESSCA) and the Scale for the Assessment and Rating of Ataxia (SARA) subscores and with the subgroup of patients with independent gait according to the 8-meter walking-time (8MW). Interactions of clinical/molecular findings with treatment response, minimally important differences (MIDs), and sample size estimations for NESSCA, SARA, Spinocerebellar Ataxia Functional Index (SCAFI) and Composite Cerebellar Functional Score (CCFS) were evaluated.

RESULTS

62 SCA3/MJD patients had been randomly assigned (1:1) for the double-blind, placebo-controlled trial. While cerebellar NESSCA (range: 0-7 points) differed between groups 0.64 points (95% CI 0.23 to 1.05, p<0.001) over the whole 48weeks of study, favoring lithium, no effect was found on non-ataxia subscores. Among patients able to perform the 8MW on baseline, NESSCA (p=0.010) and SCAFI (p=0.015) differed between groups favoring lithium. Finally, estimated sample sizes for the scales were provided.

CONCLUSION

Lithium efficacy on cerebellar NESSCA, and on SCAFI and CCFS in the primary analysis, together with the lack of effect on non-ataxia features suggests that lithium should be tested in phase 3 trials in SCA3/MJD and that ataxia scales should be preferred to multisystem neurological instruments as the primary outcome. The inclusion of early stage patients is advisable in future clinical trials in SCA3/MJD.

TRIAL REGISTRATION

clinicaltrials.gov identifier: NCT01096082.

Parkinson's disease pharmacogenomics: new findings and perspectives

Parkinson's disease (PD) is unique among neurodegenerative disorders because a highly effective pharmacological symptomatic treatment is available. The marked variability in drug response and in adverse profiles associated with this treatment led to the search of genetic markers associated with these features. We present a review of the literature on PD pharmacogenetics to provide a critical discussion of the current findings, new approaches, limitations and recommendations for future research. Pharmacogenetics studies in this field have assessed several outcomes and genes, with special focus on dopaminergic genes, mainly DRD2, which is the most important receptor in nigrostriatal pathway. The heterogeneity in methodological strategies employed by different studies is impressive. The question of whether PD pharmacogenetics studies will improve clinical management by causing a shift from a trial-and-error approach to a pharmacological regimen that takes into account the individual variability remains an open question. Collaborative longitudinal studies with larger sample sizes, better outcome definitions and replication studies are required.

NREM sleep alpha and sigma activity in Parkinson's disease: evidence for conflicting electrophysiological activity?

OBJECTIVES

Sleep EEG spectral patterns were investigated in eight newly diagnosed, non-depressed, non-demented, drug-naïve Parkinson's disease patients compared to nine controls.

METHODS

Mean relative spectral power density calculated for 0.25 Hz frequency bins and for classical EEG frequency bands.

RESULTS

Differences between patients and controls were most prominent in non-REM sleep, specially around 8.6 Hz (slow alpha), 12.5 Hz (fast alpha/slow sigma) and 15 Hz (fast sigma). Slow alpha showed lower p-values over frontal and occipital electrodes, whereas fast sigma activity was more important on central and parietal sites. Significantly increased NREM sleep alpha activity was found in left and right frontal (Mann-Whitney U=12,000, p=.021; U=14,000, p=.036), left and right central (U=14,000, p=.036), left parietal and left occipital (U=13,000, p=.027; U=15,000, p=.046) areas. Increased sigma activity was found in right frontal (U=14,000, p=.036), left central (U=12,000, p=.021), left and right parietal (U=12,000, p=.021; U=13,000, p=.027) and left occipital (U=15,000, p=.046) areas.

CONCLUSIONS

Concomitantly increased scalp EEG alpha and sigma activity was found during NREM sleep in initial Parkinson's disease.

SIGNIFICANCE

These non-REM sleep microstructure changes may represent evidence for altered electrophysiological mechanisms leading to sleep-wake instability in early disease stages.

Care of patients with Huntington's disease in South America: a survey

Huntington's disease (HD) is a rare neurodegenerative disease with a multitude of symptoms, which requires access to specialized multidisciplinary care for adequate management. The aim of this study was to survey the characteristics of care in various HD centers in South America (SA). Methods A questionnaire was sent to 24 centers involved in the care for HD patients in SA. Results Of the total 24 centers, 19 (79.2%) are academic units. The majority of centers (62.5%) are general movement disorders clinics. Multidisciplinary care is available in 19 (79.2%) centers and in 20 (83.3%) care is provided free of charge. Genetic testing and counseling are available in 25 and 66.6% of centers, respectively. The majority of centers (83.3%) have no institutional support for end-stage care. Conclusions Although HD centers in SA are committed to providing multidisciplinary care, access to genetic counseling and end-stage care are lacking in most centers.

Glucocerebrosidase gene variants in parkinsonian patients with Machado Joseph/spinocerebellar ataxia 3

Machado-Joseph disease/spinocerebellar ataxia type 3 (MJD/SCA3) may rarely presents a parkinsonian phenotype. Considering that mutations in the glucocerebrosidase (GBA) gene have been associated with Parkinson disease, we investigated whether these would be more prevalent in MJD/SCA3 patients with parkinsonian manifestations than in those without them.

METHODS

MJD/SCA3 patients with parkinsonian features were identified and compared to relatives and to a MJD/SCA3 control group with no such features. The GBA gene was sequenced and, in a subset of patients and in normal volunteers, GBA enzyme activity was measured.

RESULTS

We have identified nine index MJD/SCA3 patients with parkinsonian manifestations. Overall, GBA sequence variations were found in 3/9 MJD/SCA3 index cases with parkinsonian manifestations (33%) and in 0/40 MJD/SCA3 controls without parkinsonism (p=0.03, Fisher exact test). The GBA sequence variations found were p.K(-27)R, p.E326K, and p.T369M. The latter two sequence variations were also found in two symptomatic relatives with no parkinsonian manifestations. A MJD/SCA3 relative belonging to the first positive pedigree and carrier of the p.K(-27)R mutation also presented parkinsonian manifestations. GBA activity in MJD/SCA3 patients was similar to those found in the normal control group.

CONCLUSION

Sequence variations at the GBA gene may play a role as a minor, modifying gene of MJD/SCA3 phenotype. This hypothetical role was not related to changes in GBA activity in peripheral leukocytes.

Identification of blood microRNAs associated to Parkinsonĭs disease

The present study demonstrates that blood samples can be used as a source of miRNA identification associated to Parkinson's disease (PD). A set of six differentially expressed microRNAs were identified. They form two groups according to their expression profile in control, non-treated, early-onset and treated Parkinson's disease subjects. While miR-1, miR-22* and miR-29 expression levels allowed to distinguish non-treated PD from healthy subjects, miR-16-2*, miR-26a2* and miR30a differentiated treated from untreated patients. This study is innovative in contributing to the development of effective PD biomarkers.

Identification of blood microRNAs associated to Parkinsonĭs disease

The present study demonstrates that blood samples can be used as a source of miRNA identification associated to Parkinson's disease (PD). A set of six differentially expressed microRNAs were identified. They form two groups according to their expression profile in control, non-treated, early-onset and treated Parkinson's disease subjects. While miR-1, miR-22* and miR-29 expression levels allowed to distinguish non-treated PD from healthy subjects, miR-16-2*, miR-26a2* and miR30a differentiated treated from untreated patients. This study is innovative in contributing to the development of effective PD biomarkers.

Olfactory function and Parkinson's disease in Southern Brazil

The idiopathic Parkinson disease (IPD) is traditionally diagnosed by motor signs, but non-motor symptoms and signs are frequent and may help in the clinical diagnosis.

PURPOSE

To evaluate the olfactory function in Brazilian healthy subjects, patients with early-onset PD (EOPD) and late-onset PD (LOPD) using the Sniffin' Sticks odor-identification test (SST).

METHOD

We studied 70 patients with IPD (19 EOPD and 51 LOPD) and 70 controls matched for gender, age and years of schooling. Subjects with dementia and loss of smell for other reasons were excluded.

RESULTS

The SST showed a significant difference (p<0.001) between groups: control groups (12.0 + or - 0.3), EOPD (8.3 + or - 0.7), and LOPD (6.7 + or - 0.4) when the groups were adjusted for gender, age, disease duration, and years of schooling.

CONCLUSION

Both groups of IPD patients presented olfactory impairments, but those whose symptoms started before 45 years-old (EOPD) had better sense of smell than the LOPD patients.

WHOQOL-OLD assessment of quality of life in elderly patients with Parkinson's disease: influence of sleep and depressive symptoms

OBJECTIVE

Parkinson's disease is a neurodegenerative disease with a number of motor and non-motor features that can affect quality of life. In this study, we aimed to assess quality of life, as well as to evaluate the potential determinants of quality of life, such as sleep quality, motor and depressive symptoms, in elderly patients with Parkinson's disease.

METHOD

This was a cross-sectional study in which we applied the World Health Organization Quality of Life Assessment for Older Adults in 57 Parkinson's disease patients over 60 years of age.

RESULTS

Total World Health Organization Quality of Life Assessment for Older Adults score was found to be associated with Parkinson's disease severity (rs = -0.43; p < 0.001). World Health Organization Quality of Life Assessment for Older Adults scores for sensory abilities (facet 1) and social participation (facet 4) were higher among the patients with mild Parkinson's disease than among those in the more advanced stages (rs = -0.43; p < 0.001). Facet 1 scores were found to be associated with Pittsburgh Sleep Quality Index and Parkinson's Disease Sleep Scale score (rp = -0.46 and rp = 0.41; p < 0.001, respectively). The Geriatric Depression Scale score showed an association with the total score on the World Health Organization Quality of Life Assessment for Older Adults (rp = -0.70; p < 0.001)

CONCLUSION

Quality of life in Parkinson's disease patients can be assessed by the World Health Organization Quality of Life Assessment for Older Adults. Greater Parkinson's disease severity can worsen patient quality of life, as can the presence of depressive symptoms.

Incidental Encoding Strategies Did Not Improve Contextual Memory in Parkinson’s Disease Patients

Background. This study investigated the performance of patients with idiopathic Parkinson’s disease (PD) without dementia for incidental recognition memory and the effect of encoding strategies on contextual memory. Methods. The authors studied 21 patients with PD (ages 60-85, 12 women; Hoehn and Yahr I-III, Activities of Daily Living 70%-100%) and 22 healthy controls (ages 60-84, 18 women). Participants completed the vocabulary subtest of the Wechsler Adult Intelligence Scale and the Wisconsin Card Sorting Test (WCST). To assess the incidental recognition memory for item (object) and context (location of the object), participants of each group were assigned to 1 of 2 encoding conditions: ( a) an incidental associative instruction to bind the object to its location or ( b) a nonassociative, nonspecific instruction. Results. PD patients showed performance comparable to the control group’s on the vocabulary subtest and WCST. In contrast to controls, PD patients were unable to take advantage of the associative encoding instruction, which also had a deleterious effect on item recognition. Conclusion. This sample of participants with PD showed diminished item and context recognition memory and an impaired ability to use incidental memory encoding strategy, suggesting a compromised cognitive reserve. The fact that these alterations occurred in early stages of PD, and prior to more general cognitive alterations such as executive dysfunction, should be considered in the management of patients by using specific cognitive rehabilitation interventions.

Interleukin-6 serum levels in patients with Parkinson's disease

Several lines of evidence suggest that neuroimmune mechanisms may be involved in the neurodegenerative process of Parkinson's disease (PD). Interleukin-6 (IL-6) is increased in the nigrostriatal region and in the cerebrospinal fluid of patients with PD. IL-6 serum level was evaluated in PD patients. The effects of levodopa treatment and disease severity on IL-6 were also studied. The IL-6 levels were similar between PD patients (treated and not treated) and controls. However, there was a negative correlation of IL-6 levels and the activities of daily living scale (P < 0.05), indicating that patients with more severe disease have higher levels of this cytokine. No correlation involving levodopa treatment and IL-6 serum level was found. The results suggest that only marginal effects of IL-6 occur on the peripheral immune system, and that the role of IL-6 and others neuroimmune factors needs to be well elucidated on PD.

Psychometric properties of the Parkinson's Disease Sleep Scale--Brazilian version

Parkinson's Disease Sleep Scale (PDSS) is a specific scale for the assessment of sleep disturbances in subjects with Parkinson's Disease (PD). This cross-sectional study set out to validate the PDSS in a Brazilian Portuguese Version (PDSS-BR). Ninety-five patients with PD participated in the study; their PD symptoms were evaluated by Unified Parkinson's Disease Rating Scale (UPDRS sections I-IV) and Hoehn and Yahr scale. Patients completed Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), Beck Depression Inventory (BDI) and PDSS-BR. PDSS-BR internal consistency was satisfactory (Cronbach's alpha: 0.82; all PDSS-BR items were significantly and positively associated with total score). Test-retest reliability for total PDSS-BR score was 0.94. PDSS-BR score was highly correlated with sleep PSQI scale (r(s) = -0.63; p < 0.0001) and moderately with ESS (r(s) = -0.32; p < 0.001) and UPDRS sections I (r(s) = -0.38; p < 0.0001) and II (r(s) = -0.36; p < 0.0001) and BDI (r(s) = -0.55; p < 0.0001). Depressive symptoms, as determined by the BDI, were associated with significantly worse quality of nocturnal sleep, as measured by the PDSS-BR. The psychometric attributes of the PDSS-BR were satisfactory and consistent with those of previous studies. In summary, PDSS-BR can be useful for clinical and research purposes in Brazil.

Did depressive symptoms affect recognition of emotional prosody in Parkinson's disease?

OBJECTIVE

Evaluate the influence of depressive symptoms on the recognition of emotional prosody in Parkinson's disease (PD) patients, and identify types of emotion on spoken sentences.

METHODS

Thirty-five PD patients and 65 normal participants were studied. Dementia was checked with the Mini Mental State Examination, Clinical Dementia Rating scale, and DSM IV. Recognition of emotional prosody was tested by asking subjects to listen to 12 recorded statements with neutral affective content that were read with a strong affective expression. Subjects had to recognize the correct emotion by one of four descriptors (angry, sad, cheerful, and neutral). The Beck Depression Inventory (BDI) was employed to rate depressive symptoms with the cutoff 14.

RESULTS

Total ratings of emotions correctly recognized by participants below and above the BDI cutoff were similar among PD patients and normal individuals. PD patients who correctly identified neutral and anger inflections presented higher rates of depressive symptoms (p = 0.011 and 0.044, respectively). No significant differences were observed in the normal group.

CONCLUSIONS

Depression may modify some modalities of emotional prosody perception in PD, by increasing the perception of non-pleasant emotions or lack of affection, such as anger or indifference.

A Double-blind, Randomized, Crossover Study of Prosigne Versus Botox in Patients With Blepharospasm and Hemifacial Spasm

There is a lack of evidence on the clinical efficacy and safety of the recently released Chinese botulinum toxin serotype A (Prosigne) for the treatment of focal dystonias and hemifacial spasm. Determining a more precise role of Prosigne in the treatment of such conditions is of paramount importance, because botulinum toxin type A treatments have a huge economic implication in health services, especially in developing countries. The aim of our study was to compare the efficacy and safety of Prosigne in the treatment of blepharospasm and hemifacial spasm in comparison to Botox. We performed a double-blind, randomized, crossover study enrolling 26 patients. There were no significant differences between Prosigne and Botox regarding subjective global improvement, response onset, efficacy duration, and incidence and severity of adverse events. Our results suggest that Prosigne and Botox are comparable with respect to efficacy and safety for the short-term treatment of blepharospasm and hemifacial spasm.

Levels of vascular cell adhesion molecule-1 and endothelin-1 in ischemic stroke: a longitudinal prospective study

OBJECTIVES

To determine levels of vascular cellular adhesion molecule (VCAM)-1 and endothelin (ET)-1 in patients with stroke.

DESIGN AND METHODS

Thirty-four patients were prospectively studied. Plasma levels of VCAM-1 and ET-1 were measured by ELISA within 72 h of the event, at 7 and 90 days.

RESULTS

Levels of VCAM-1 increased overtime, whereas ET-1 values were initially and persistently elevated.

CONCLUSIONS

Increased circulating levels of VCAM-1 and ET-1 are present during stroke.

Quality of life in a Brazilian sample of patients with Parkinson's disease and their caregivers

OBJECTIVE: Parkinson's disease is a common neurodegenerative disorder characterized by motor disabilities and increasing dependence on others for daily life activities with consequent impact on patients' and caregivers' quality of life. METHOD: A cross-sectional study was performed in which quality of life was assessed by the WHOQOL-BREF questionnaire in 21 patients with Parkinson's disease and their respective caregivers. RESULTS: Significant differences between patients and caregivers were found in physical (p < 0.001) and psychological (p = 0.002) domains. In the Parkinson's disease group there was a significant inverse correlation between the psychological domain and duration of disease (p = 0.01), as well as between social domain and severity of disease (p = 0.001). There was a positive correlation between physical domain scores and number of people living in the same house (p = 0.02). The only significant finding in the group of caregivers was an inverse correlation between the social domain and the patients´ age (p = 0.04). CONCLUSION: Duration, severity of the disease and the number of people living in the same house were the most important predictors of quality of life of Parkinson's disease patients. The age of the patients was the only significant predictor found in the caregivers' quality of life. In order to complement our findings, further short-form questionnaires should be validated for Brazilian samples of Parkinson's disease.

Evaluation of sympathetic skin response in Parkinson's disease

There is no clear definition on the role of sympathetic skin response (SSR) in the evaluation of patients with Parkinson's disease (PD). We recorded the SSR of the palms of 64 controls and 46 patients with PD to electrical stimulation of the median nerve at the wrist. We analyzed onset latency and peak-to-peak amplitude. A study of parasympathetic function (R-R interval analysis) was also undertaken. We found that patients with PD had more absent SSRs than controls. The mean amplitude of the SSR was significantly reduced in both lower and upper limbs of PD patients in comparison with control subjects (p<0.001). The onset latency was longer in the lower limbs of these patients in respect to the control group (p<0.003). There was a significant inverse correlation between SSR amplitudes and age, severity and late onset of the disease. There was no association of these parameters with dysautonomic symptoms or R-R interval variation. In conclusion, there is a significant association between altered SSR and PD and an inverse correlation in this group of patients between SSR values and older age, greater severity and later onset of disease. Therefore, the study of SSR may provide valuable information on cholinergic sympathetic function in patients with PD.

Hyperhidrosis in Parkinson's disease

We studied the sudomotor skin response (SSR) in patients with Parkinson's disease with and without symptomatic hyperhidrosis. The study was carried out in 13 patients who complained of excessive sweating and in 37 patients who did not have excessive sweating. Patients were matched for age, sex, degree of impairment, duration of the disease, and number and severity of autonomic disturbances. Excessive sweating involved mainly the face, head, and trunk. The SSR was recorded from the palm of the hands to electrical stimulation of the median nerve at the wrist. We analyzed onset latency, peak to peak amplitude, and waveform. Patients with hyperhidrosis had more often absent responses (chi(2) = 5.292; P = 0.021), their responses were of lower mean amplitude (analysis of variance [ANOVA]; F[2,101] = 11.678; P < 0.001), and they had a reduced number of responses with a predominantly negative component (chi(2) = 8.493; P = 0.004) than patients who did not complain of sweating disturbances. Our results indicate that excessive sweating in Parkinson's disease concurs with decreased activation of sweat glands in the palms of the hands and suggests that axial hyperhidrosis could be a compensatory phenomenon for reduced sympathetic function in the extremities.

S100B and NSE serum concentrations in Machado Joseph disease

BACKGROUND

NSE and S100B are considered as neuronal and glial peripheral markers of central nervous system pathologies, respectively. We evaluated the potential use of S100B and NSE serum concentrations as peripheral markers of symptomatic patients with Machado Joseph disease (MJD).

METHODS

We measured S100B and NSE peripheral concentrations of 22 MJD patients and compared with healthy subjects concentrations. The correlations of both markers with CAG repeat size, age of onset, disease duration, and the scores of the Extended Disability Status Scale of Kurtzke, Unified Parkinson's Disease Rating Scale, and the Montgomery-Asberg depression rating scale were also assessed.

RESULTS

S100B serum concentrations between control and MJD subjects were not statistically different, whereas NSE serum concentrations were higher in MJD patients than in control subjects (p=0.00001). S100B presented a moderate correlation with disease duration and depression score, whereas NSE presented a moderate correlation with depression score and a good negative correlation with EDSS score.

CONCLUSIONS

Symptomatic MJD patients present increased concentrations of NSE and normal concentrations of S100B in blood.

Head tremor and progressive multifocal leukoencephalopathy in AIDS patients: report of two cases

Progressive multifocal leukoencephalopathy (PML) is caused by replication of JC virus in oligodendrocytes of immunocompromised patients. Common manifestations are focal motor and sensory deficits, gait abnormalities, speech and language disturbances, cognitive disorders, headache, and visual impairment. Although the occurrence of movement disorders is rare in PML, bradykinesia, rigidity, dystonia, myoclonic jerks and myoclonic ataxia have been described. Head tremor associated with PML has not been previously reported. We report two cases of PML in whom head tremor was present.

S100B and NSE serum levels in patients with Parkinson's disease

We evaluated S100B protein and neuron-specific enolase (NSE) serum levels in Parkinson's disease (PD) patients and their correlation with the severity of disease. The levels of S100B (P=0.16) and NSE (P=0.39) between PD and controls were similar. However, S100B levels correlated positively with the Hoehn and Yahr scale (r=0.368; P=0.02) and negatively with the Activities of Daily Living (ADL) scale (r=-0.431; P=0.006). Therefore, S100B and NSE may not have a diagnostic role in PD, but S100B may have a potential role as a marker of disease progression. The study of S100B may also contribute to elucidate the controversial role of glial cells in PD.

Selegiline increases heme oxygenase-1 expression and the cytotoxicity produced by dopamine treatment of neuroblastoma SK-N-SH cells

Increased dopamine catabolism may be associated with oxidative stress and neuronal cell death in Parkinson's disease. The present study was carried out to examine the effect of dopamine on the expression of heme oxygenase-1 and -2 (HO-1 and HO-2) in human neuroblastomas (SK-N-SH cell line) and the effects of selegiline and antioxidants on this expression. Cells were kept with close control of pH and were incubated with varying concentrations of dopamine (0.1-100 microM) for 24 h. HO-1 and HO-2 cDNA probes were prepared by reverse transcription-polymerase chain reaction amplification. The mRNA expression of HO-1 and HO-2 was measured by Northern blot analysis. The levels of HO-1 mRNA increased after dopamine treatment, in a dose-dependent manner, in all cell lines studied, whereas levels of the two HO-2 transcripts did not. The HO-1 and HO-2 protein expression was analyzed by Western blotting. HO-1 protein was undetectable in untreated SK-N-SH cells and increased after treatment with dopamine. In contrast, the HO-2 protein (36 kDa) was detected in untreated cells and the levels did not change as a result of treatment. Alpha-tocopherol (10-100 microM) and ascorbic acid (100 microM) did not attenuate the effects of dopamine. Selegiline (10 microM) produced significant increase (P < 0.01) in the induction of HO-1 by dopamine (more than six times the control values). The increased expression of HO-1 following dopamine treatment indicates that dopamine produces oxidative stress in this cell line.

Holmes tremor in association with bilateral hypertrophic olivary degeneration and palatal tremor: chronological considerations. Case report

Hypertrophic olivary degeneration (HOD) is a rare type of neuronal degeneration involving the dento-rubro-olivary pathway and presents clinically as palatal tremor. We present a 48 year old male patient who developed Holmes' tremor and bilateral HOD five months after brainstem hemorrhage. The severe rest tremor was refractory to pharmacotherapy and botulinum toxin injections, but was markedly reduced after thalamotomy. Magnetic resonance imaging permitted visualization of HOD, which appeared as a characteristic high signal intensity in the inferior olivary nuclei on T2- and proton-density-weighted images. Enlargement of the inferior olivary nuclei was also noted. Palatal tremor was absent in that moment and appears about two months later. The delayed-onset between insult and tremor following structural lesions of the brain suggest that compensatory or secondary changes in nervous system function must contribute to tremor genesis. The literature and imaging findings of this uncommon condition are reviewed.

Use of fluoxetine for treatment of Machado-Joseph disease: an open-label study

CONTEXT

Machado-Joseph Disease (MJD/SCA3) is an autosomal dominant spinocerebellar degeneration that evolves to disability and death. Experimental data have shown that serotonin is an important cerebellar neurotransmitter and that impairment of the serotoninergic cerebellar system can induce cerebellar ataxia.

OBJECTIVES

To evaluate the efficacy of fluoxetine, a serotonin reuptake inhibitor, in treating neurologic dysfunction in patients with MJD.

PATIENTS AND METHODS

Thirteen MJD patients were treated with fluoxetine (20 mg/day) and were followed-up for 6 weeks. Outcome measures included functional capacity, standardized neurologic and cognitive ratings. The Montgomery-Asberg depression rating scale was used to control depressive symptoms.

RESULTS

There was no significant improvement in motor abilities after 6 weeks of treatment.

CONCLUSIONS

These results suggest that fluoxetine has no benefit in motor function of patients with MJD/SCA3.