Treatable inherited rare movement disorders

There are many rare movement disorders, and new ones are described every year. Because they are not well recognized, they often go undiagnosed for long periods of time. However, early diagnosis is becoming increasingly important. Rapid advances in our understanding of the biological mechanisms responsible for many rare disorders have enabled the development of specific treatments for some of them. Well-known historical examples include Wilson disease and dopa-responsive dystonia, for which specific and highly effective treatments have life-altering effects. In recent years, similarly specific and effective treatments have been developed for more than 30 rare inherited movement disorders. These treatments include specific medications, dietary changes, avoidance or management of certain triggers, enzyme replacement therapy, and others. This list of treatable rare movement disorders is likely to grow during the next few years because a number of additional promising treatments are actively being developed or evaluated in clinical trials. © 2017 International Parkinson and Movement Disorder Society.

Premotor symptoms and the risk of Parkinson's disease: A case-control study in Mexican population

OBJECTIVES

To assess the prevalence of pre-motor symptoms and estimate the risk for developing Parkinson's disease in Mexican population.

PATIENTS AND METHODS

A case-control study was carried out with consecutive subjects with Parkinson's disease from two different referral centers in Mexico. Gender- and age-matched controls were randomly selected from the participating hospitals. All subjects were assessed using a structured questionnaire for the assessment of pre-motor symptoms (hyposmia, depression, anxiety, constipation, and sleep disorders). Odds ratios (OR) were calculated using logistic regression analysis.

RESULTS

A total of 430 subjects with PD and 430 healthy subjects were included. Premotor symptoms prevalence was 77.7% (n=334) for the PD group, compared to 41.3% (n=178) in the control group (p<0.001). After logistic multivariate analysis, previous history of hyposmia (OR 2.02 [95% CI 1.33-3.06]), depression (OR 2.52 [95% CI 1.67-3.84]), anxiety (OR 4.37 [95% CI 2.73-6.98]) and sleep disorders (OR 2.03 [95% CI 1.41-2.93]) were independently associated with Parkinson's disease. Overall prediction success of the model was 81.2% for controls and 61.2% for subjects with PD.

CONCLUSION

All five premotor symptoms assessed were more commonly reported in PD subjects than healthy controls. The presence of non-motor symptoms yield a prediction success of 71.2% to discriminate between PD subjects and healthy controls.

Association of polymorphisms and reduced expression levels of the NR4A2 gene with Parkinson's disease in a Mexican population

INTRODUCTION

The NR4A2 transcription factor is important in the development, survival and phenotype of dopaminergic neurons and it is postulated as a possible biomarker for Parkinson's disease (PD). Therefore, our aim was to analyze in a sample of a Mexican population with idiopathic PD, mutations (in two hotspot mutation regions) and two polymorphisms (rs34884856 in promotor and rs35479735 intronic regions) of the NR4A2 gene. We also evaluate the levels of NR4A2 gene expression in peripheral blood for a Mexican population, and identify whether they are associated with NR4A2 gene polymorphisms.

METHODS

We conducted a case-control study, which included 227 idiopathic PD cases and 454 unrelated controls. Genetic variants of the NR4A2 gene were genotyped by high-resolution melting (HRM) and validated by an automated sequencing method. The gene expression was performed in peripheral blood using a real-time polymerase chain reaction.

RESULTS

The rs35479735 polymorphism was associated with a higher risk of developing PD. In addition, NR4A2 gene expression was significantly decreased in patients with PD. Linkage disequilibrium analysis showed a haplotype H4 (3C-3G) that showed lower levels of expression, and contained the risk alleles for both polymorphisms.

CONCLUSIONS

In summary, this is the first study in a Mexican population that considers the analysis of NR4A2 in patients with PD. An association was identified between genotype and mRNA expression levels of NR4A2 in patients with PD. These results suggest that polymorphisms and expression of the NR4A2 gene could play an important role in the risk of developing PD in Mexican populations.

Clinical Determinants of Parkinson's Disease-associated Pain Using the King's Parkinson's Disease Pain Scale

Background

Pain is a frequent feature in Parkinson's disease (PD). Current knowledge on pain and its associated factors in PD has been obtained using nondisease-specific tools. Recently, the King's Parkinson's Disease Pain Scale (KPPS) was published as the first disease-specific scale. The aim of this study was to assess PD-associated pain and its main determinants using the KPPS.

Methods

A cross-sectional study was carried out. Consecutive patients with PD were recruited from a movement disorders clinic. Clinical and demographical data were collected. The KPPS, the Movement Disorders Society Unified Parkinson's Disease Rating Scale, and the Non-Motor Symptoms Scale were used to assess all participants.

Results

In total, 314 patients were included. Overall, 88.6% of the sample reported at least 1 type of pain. The mean ± standard KPPS score was 18.8 ± 19.5. Factors associated with higher KPSS scores were female sex (P < 0.001), levodopa treatment (P < 0.001), the presence of depressed mood (P < 0.001), wearing off (P = 0.003), and dyskinesia (P = 0.005). Participants who had postural instability and gait difficulty motor subtypes had higher KPPS scores compared with those who had other subtypes. Multivariate regression analysis showed that only sex, motor subtype, depressed mood, and Non-Motor Symptoms Scale sleep/fatigue domain scores achieved statistical significance as determinants (all P < 0.01).

Conclusion

PD-associated pain is a frequent symptom that tends to increase in both frequency and severity as disease progresses. Risk factors for increased burden include female gender, postural instability and gait difficulty motor subtypes, mood alterations, and sleep/fatigue disturbances.

Self-Assessment of Disability in Parkinson's Disease: The MDS-UPDRS Part II Versus Clinician-Based Ratings

Background

Parkinson's disease (PD) is characterized by motor and nonmotor symptoms that progress with time, causing disability. The performance of a disease-specific, self-applied tool for assessing disability, the MDS-UPDRS Part II, is tested against generic and rater-based rating scales.

Methods

An international, cross-sectional, observational study was performed. Patients were assessed with the Hoehn and Yahr (HY) and five disability measures: MDS-UPDRS Part II, Schwab and England Scale (S&E), Clinical Impression of Severity Index-PD (CISI-PD) Disability item, Barthel Index (BI), and Rapid Assessment of Disability Scale (RADS). Data analysis included correlation coefficients, Mann-Whitney and Kruskal-Wallis tests, and intraclass-correlation coefficient for concordance.

Results

The sample was composed of 451 patients, 55.2% men, with a mean age of 65.06 years (SD = 10.71). Disability rating scales correlated from |0.75| (CISI-PD Disability with BI) to 0.87 (MDS-UPDRS Part II with RADS). In general, MDS-UPDRS Part II showed high correlation coefficients with clinical variables and satisfactory concordance with the rest of disability measures, with ICC ranging from 0.83 (with BI) to 0.93 (with RADS). All disability rating scales showed statistical significant differences in the sample grouped by sex, age, disease duration, and severity level.

Conclusions

The MDS-UPDRS Part II showed an appropriate performance to assess disability in PD, even better than some rater-based, generic or specific, scales applied in this study.

Impact of Neuropsychiatric Symptoms on the Quality of Life of Subjects with Parkinson's Disease

BACKGROUND

Neuropsychiatric symptoms in Parkinson's disease (PD) are frequent. Impact of neuropsychiatric symptoms on quality of life has recently become a relevant topic of research due to its potential to develop targeted therapies to improve quality of life.

OBJECTIVE

To determine the impact of neuropsychiatric symptoms in patients with PD using the Parkinson's Disease Questionnaire Short Form (PDQ-8).

METHODS

Consecutive patients with PD were evaluated with the Scale for Evaluation of Neuropsychiatric Disorders in Parkinson's disease (SEND-PD) and PDQ-8 scales separately. Association between neuropsychiatric symptoms and quality of life was explored using, means comparisons, correlation coefficients and multiple regression models.

RESULTS

A total of 492 patients were included for the study. Overall, 44.5% had psychotic symptoms, 76.5% had alterations on mood/apathy domains, and 27% had an impulse control disorder. All neuropsychiatric symptoms had an effect on the PDQ-8 with a moderate to large effect size. Correlation coefficients ranged from 0.17 to 0.63 between neuropsychiatric symptoms and quality of life (p <  0.001, in all cases). The regression model showed that mood/apathy alterations and impulse control disorders, along with MDS-UPDRS III accounted for 49.8% of variance in the PDQ-8 simplified index (F = 122.98; p <  0.001). Mood/apathy alterations showed the highest correlation coefficient (0.63, p <  0.001) and β (0.53, p <  0.001).

CONCLUSIONS

Both the presence and severity of neuropsychiatric symptoms, in particular mood/apathy alterations,had a significant impact on quality of life in subjects with PD.

Impact of a Movement Disorders Clinic on the trends of Parkinson's Disease Consultations at a Tertiary Referral Center

BACKGROUND

Outpatient clinics for movement disorders provide specialized diagnosis and treatment services for the specific needs of this patient population.

OBJECTIVE

Describe the impact of implementing a Movement Disorder Clinic on the trends of consultations per year and hospitalizations of subjects with Parkinson's disease at a tertiary referral center.

METHODS

A retrospective study was carried out. We collected data from the Clinical File Archive and the Epidemiology Department at the National Institute of Neurology and Neurosurgery in Mexico. Data from January 1, 1999 through December 31, 2015 were included for analysis.

RESULTS

The number of total consultations had an increase of 632.1% between 1999 and 2015. Follow-up visits represented up to 95% of the consultations. Peaks found correlated with the inclusion of new specialists in the clinic. Regarding hospitalization, the number of patients discharged with a diagnosis of Parkinson's disease increased from a median of 17 (range 9-35) to 46 patients (range 31-53) per year.

CONCLUSIONS

The implementation of a multidisciplinary Movement Disorders Outpatient Clinic in a tertiary referral center had a direct impact on the total number of consultations per year, mainly follow-up visits. The latter may reflect in an improvement in the quality of care.

Analysis of four scales for global severity evaluation in Parkinson's disease

Global evaluations of Parkinson’s disease (PD) severity are available, but their concordance and accuracy have not been previously tested. The present international, cross-sectional study was aimed at determining the agreement level among four global scales for PD (Hoehn and Yahr, HY; Clinical Global Impression of Severity, CGIS; Clinical Impression of Severity Index, CISI-PD; and Patient Global Impression of Severity, PGIS) and identifying which of them better correlates with itemized PD assessments. Assessments included additional scales for evaluation of the movement impairment, disability, affective disorders, and quality of life. Spearman correlation coefficients, weighted and generalized kappa, and Kendall’s concordance coefficient were used. Four hundred thirty three PD patients, 66% in HY stages 2 or 3, mean disease duration 8.8 years, were analyzed. Correlation between the global scales ranged from 0.60 (HY with PGIS) to 0.91 (CGIS with CISI-PD). Kendall’s coefficient of concordance resulted 0.76 (P<0.0001). HY and CISI-PD showed the highest association with age, disease duration, and levodopa-equivalent daily dose, and CISI-PD with measures of PD manifestations, disability, and quality of life. PGIS and CISI-PD correlated similarly with anxiety and depression scores. The lowest agreement in classifying patients as mild, moderate, or severe was observed between PGIS and HY or CISI-PD (58%) and the highest between CGIS and CISI-PD (84.3%). The four PD global severity scales agree moderately to strongly among them; clinician-based ratings estimate PD severity, as established by other measures, better than PGIS; and the CISI-PD showed the highest association with measures of impairment, disability, and quality of life.

[Prevalence of neuropsychiatric disorders in drug-naive subjects with Parkinson's disease (PD)]

INTRODUCTION

Parkinson's disease is characterized by a broad spectrum of neuropsychiatric manifestations. Its pathophysiology has been associated with the disease itself as well as with the dopaminergic treatment.

MATERIAL AND METHODS

A cross-sectional study was conducted in drug-naive patients with early Parkinson's disease. All participants were evaluated through a set of scales for specific neuropsychiatric symptoms including: cognition, depression, anxiety, apathy, psychosis, and impulse control disorder.

RESULTS

A total of 63 patients with Parkinson were included, of whom 26 (41.3%) subjects had some degree of cognitive impairment; seven (11.1%) had depression and 11 (15.8%) subjects had anxiety. Regarding the other symptoms, a total of 12 (19%) patients showed apathy, seven (11.1%) had psychosis, and eight (12.6%) patients had symptoms related to impulse control disorders.

CONCLUSION

Neuropsychiatric disorders are common in drug-naive patients with early Parkinson's disease. Given the impact of these symptoms on quality of life, identification and proper treatment is essential.

Parkinson disease and progressive supranuclear palsy: protein expression in skin

Objective

This study characterizes the expression of tau (p‐tau) and α‐synuclein (α‐syn) by immunohistochemistry in the skin of three different populations: healthy control (HC), Parkinson disease (PD), and progressive supranuclear paralysis (PSP) subjects, with the purpose of finding a biomarker that could differentiate between subjects with PD and PSP.

Material and Methods

We evaluated the presence of p‐tau and α‐syn in a pilot study in the skin of three distinct groups of patients: 17 healthy subjects, 17 patients with PD, and 10 patients with PSP. Four millimeters punch biopsies were obtained from the occipital area and analyzed by immunohistochemistry using antibodies against α‐syn and phosphorylated species of tau. PHF (paired helical filaments) antibody identifies p‐tau in both normal and pathological conditions and AT8 recognizes p‐tau characteristic of pathological conditions. Differences between the three groups were assessed by quantification of immunopositive areas in the epidermis.

Results

The immunopositivity pattern of p‐tau and α‐syn was significantly different among the three groups. Healthy subjects showed minimal staining using AT8 and α‐syn. The PD group showed significantly higher α‐syn and AT8 immunopositivity, while the PSP group only expressed higher AT8 immunopositivity than HCs.

Conclusion

These data suggest that the skin reflects brain pathology. Therefore, immunohistochemical analysis of p‐tau and α‐syn in the skin can be useful for further characterization of PD and PSP.

A systematic review and mixed treatment comparison of monotherapy in early Parkinson's disease: implications for Latin America

Parkinson's disease (PD) is the second most common neurodegenerative disease. There are no clinical trials comparing all available pharmacological therapies for the treatment of early PD. The objective of this review is to indirectly analyze the efficacy of antiparkinson drugs currently available in Latin America. A systematic review was performed exploring only placebo-controlled randomized trials comparing antiparkinson monotherapy (levodopa, pramipexole, rasagiline, or selegiline) in patients with PD on Hoehn and Yahr stages I through III published from January 1994 to May 2014. The primary outcome was the mean change in the Unified PD Rating Scale (UPDRS) I, II and III. A mixed treatment comparison analysis (indirect comparisons) through a random-effects model was performed. Levodopa demonstrated the highest effects in terms of UPDRS score improvement both from baseline and when compared to other treatments. Levodopa showed a 60.1% probability of granting the greatest reduction in UPDRS I, II and III.

No Difference on Adherence Between Immediate-Release Versus Extended-Release Dopamine Agonists in Uninsured Subjects with Parkinson's Disease

Background

Pharmacological management of subjects with Parkinson's disease (PD) is complex. Regardless of drug selection, adherence is one of the main concerns. Nonadherence is associated with poor symptomatic control and low quality of life. In general, adherence to once-a-day formulations is thought to be better in comparison to 3-times-daily dosing.

Methods

A cross-sectional study was carried out. Consecutive uninsured subjects diagnosed with PD were treated either with an immediate- or extended-release dopamine agonist formulation. Clinical and demographic data were collected. Subjects were assessed using the International Parkinson and Movement Disorder Society UPDRS. Adherence was evaluated using the Morisky-Green test (MGT).

Results

A total of 314 (175 males and 139 females) subjects with PD were included. In regard to treatment, 188 (59.9%) were on an immediate-release dopamine agonist and 126 (40.1%) on an extended-release dopamine agonist. According to the MGT, 21 (6.7%) subjects were classified as nonadherent, 273 (86.9%) with a low adherence, and only 20 (6.4%) were considered with high adherence. Dopamine agonist levodopa equivalent daily dose was higher in the extended-release group (296.6 ± 112.4 vs. 231.3 ± 133.4; P = 0.011); also, these subjects had more years of formal education (12.3 ± 5.2 vs. 9.5 ± 5.2; P = 0.630). No difference in adherence levels was found (P = 0.802) between subjects treated with an immediate-release dopamine agonist and those receiving an extended-release formulation.

Conclusions

Overall adherence in subjects with PD is low. Use of an extended-release over an immediate-release dopamine agonist formulation in this study population is not associated with a better adherence.

Electroconvulsive therapy in Parkinson's disease

Purpose To analyze the effectiveness of electroconvulsive therapy for the management of depression and/or psychosis refractory to drug therapy in patients with Parkinson disease.Methods A retrospective study was carried out including patients treated with electroconvulsive therapy during the period between 2002 and 2013. A review of the literature was performed.Results A total of 27 patients were included. In regards to the neuropsychiatric diagnosis, 14 patients had major depression, 12 patients had both psychosis and depression, and only one patient had isolated psychosis. The mean number of electroconvulsive therapy sessions was 12 ± 2.8. After electroconvulsive therapy, all patients showed a statistically significant improvement in the Brief Psychiatric Rating scale (reduction of 52% points) and Hamilton Depression Rating Scale (reduction of 50% points) independent of the presence of psychosis, depression or both.Conclusion Electroconvulsive therapy is effective for the treatment of refractory neuropsychiatric symptoms in Parkinson's disease.

Pan-American Consortium of Multiple System Atrophy (PANMSA). A Pan-American multicentre cohort study of multiple system atrophy

BACKGROUND

Multiple system atrophy (MSA) is an adult-onset and rapidly progressive, neurodegenerative condition that presents with autonomic dysfunction, parkinsonism, cerebellar ataxia and corticospinal deficits. Clinical, demographic and epidemiological data from different regions have provided valuable information concerning the natural history of MSA. There are no published data of Multiple System Atrophy (MSA) in Latin American countries.

OBJECTIVE

To describe clinical and epidemiological data of patients with "possible" MSA from seven referral movement disorders centers from Argentina, Chile, Mexico, Peru and United States.

METHODS

We conducted a retrospective, observational, cross-sectional Pan-American multicentre cohort study of MSA.

RESULTS

The sample was composed of 82 females and 77 men with the diagnosis of "possible" MSA with a mean age at onset of 65 ± 10 years. 67.29% of the individuals had a MSA-P variant with a mean age at onset of 61.47 ± 10.28 years, whereas the mean age at onset in the MSA-C patients was 57.44 ± 10.58 years. Interestingly, MSA-C-was more prevalent in Non-Caucasian (50-Mestizo and 2 Asian patients) than Caucasians (51.92% vs. 20.79%, p = 0.0001). Dysautonomic symptoms were present in 95.6% of the patients, parkinsonism in 85.5%, pyramidal signs in 25.8% and depression in 48.4% of the patients.

CONCLUSIONS

Our epidemiological and clinical data appears to be similar to other Western international series, however, of note, the MSA-C phenotype was predominant in Non-Caucasians, more specifically the Mestizo population. This observation opens a new path to explore. Larger prospective epidemiologic studies in Latin America may provide valuable information concerning MSA in the region.

Convergent validation of EQ-5D-5L in patients with Parkinson's disease

INTRODUCTION

The European Quality of Life Questionnaire 5 level version (EQ-5D-5L) is a recently updated instrument to assess Health-Related Quality of Life (HRQoL) that has not been validated extensively. The main objective of this study was to evaluate the internal consistency and convergent validation of the EQ-5D-5L in a large sample of subjects with Parkinson's disease (PD).

METHODS

A cross-sectional study was carried out. Consecutive Mexican subjects with PD were included. HRQoL was assessed using the EQ-5D-5L and the PDQ-8. Validity of the EQ-5D-5L was assessed determining its association with clinical ratings of disease severity, as well as correlation with PDQ-8. Additionally, performance was evaluated along predefined groups based on clinical and demographic data of known determinants of quality of life.

RESULTS

A total of 585 patients were included for this study. A strong correlation was found between EQ-5D-5L index and PDQ-8 index (Spearman's correlation coefficient=-0.75; p<0.001). Correlation between EQ-5D-5L index and PDQ-8 index remained strong (-0.60 to -0.78; p values <0.001) through all predefined groups. EQ-5D-5L scored higher in those patients with dyskinesia, wearing off, freezing, postural instability, cognitive impairment or depressive mood (p values <0.001).

CONCLUSION

The EQ-5D-5L is a valid instrument for evaluating HRQoL in PD, performing adequately irrespective of heterogeneous clinical and demographic characteristics, and showing to be sensitive to features of advanced disease and treatment complications.

Prevalence and correlates of sleep disorders in Parkinson's disease: a polysomnographic study

OBJECTIVE

Sleep disorders in Parkinson's disease are very common. Polysomnography (PSG) is considered the gold standard for diagnosis. The aim of the present study is to assess the prevalence of nocturnal sleep disorders diagnosed by polysomnography and to determine the associated clinical factors.

METHOD

A total of 120 patients with Parkinson's disease were included. All patients underwent a standardized overnight, single night polysomnography.

RESULTS

Ninety-four (78.3%) patients had an abnormal PSG. Half of the patients fulfilled criteria for sleep apnea-hypopnea syndrome (SAHS); rapid eye movement behavior disorder (RBD) was present in 37.5%. Characteristics associated with SAHS were age (p = 0.049) and body mass index (p = 0.016). Regarding RBD, age (p < 0.001), left motor onset (p = 0.047) and levodopa equivalent dose (p = 0.002) were the main predictors.

CONCLUSION

SAHS and RBD were the most frequent sleep disorders. Higher levodopa equivalent dose and body mass index appear to be risk factors for RBD and SAHS, respectively.

Proton Magnetic Resonance Spectroscopy Changes in Parkinson's Disease With and Without Psychosis

BACKGROUND

Psychosis prevalence in Parkinson's disease is estimated at 8-30%. Proton magnetic resonance spectroscopy measures specific metabolites as markers of cell functioning.

OBJECTIVE

To study N-acetyl-aspartate and glutamate levels in the caudate and putamen nuclei in subjects with Parkinson's disease with and without psychosis.

METHODS

We included 20 non-demented Parkinson's disease patients with psychosis and 20 Parkinson's disease patients without psychosis matched for age, sex, disease duration, and levodopa equivalent daily dose, all attended at an academic medical center. Proton magnetic resonance spectroscopy scans were performed in a 3T GE whole-body scanner.

RESULTS

Decreased glutamate levels scaled to creatine were found in the dorsal caudate (p = 0.005) and putamen (p = 0.007) of the Parkinson's disease psychosis group compared with the without psychosis group. Glutamate plus glutamine levels scaled to creatine and N-acetyl-aspartate levels scaled to creatine were also significantly reduced in the dorsal caudate of the Parkinson's disease with psychosis group (p = 0.018 and p = 0.011, respectively). No group differences were found for any of the other metabolites in the two regions of interest.

CONCLUSIONS

Our findings suggest that decreased metabolite levels in specific brain areas may be implicated in the development of psychosis in Parkinson's disease.

[Prevalence, associated factors and phenomenology of psychosis in patients with Parkinson's disease]

INTRODUCTION

Psychosis associated with Parkinson's disease is a major neuropsychiatric complication; it has been reported that 60% of patients will develop psychosis during the disease evolution. Its pathophysiology is multifactorial and clinically psychotic phenomena include minor hallucinations and confusional states.

MATERIAL AND METHODS

We performed a cross-sectional study in patients with Parkinson's disease from a tertiary hospital using a thoughtful neurological and neuropsychiatric evaluation along with specific scales for non-motor symptoms, depression, cognition, and presence and severity of psychotic symptoms and hallucinations.

RESULTS

We included a total of 236 patients with Parkinson's disease, of which 33 (13.9%) patients met the criteria for psychosis at the time of the evaluation. Visual hallucinations were the most common symptom. Age (p = 0.004), age at onset of the disease (p = 0.007) and its duration (p = 0.004), use of levodopa (p = 0.02), and use of amantadine (p = 0.004) were the main factors associated with the presence of psychosis.

CONCLUSION

Psychosis in Parkinson's disease is a relatively common manifestation and is mainly associated with clinical and demographic factors. Early recognition will optimize management and improve the quality of life of patients and their caregivers.

Parkinson's disease severity levels and MDS-Unified Parkinson's Disease Rating Scale

BACKGROUND

Severity of PD is usually assessed by means of the motor and disability-based Hoehn and Yahr staging (HY), or clinician and patient global perceptions. Scores of more detailed assessments, as the MDS-UPDRS, have not been translated to a grading that allows assignment of score sections to severity levels. The objective of the present study is to determine cut-off points for PD severity levels based on the MDS-UPDRS.

METHODS

International, observational study. Applied assessments were: HY, MDS-UPDRS, Clinical Impression for Severity Index, and Clinical and Patient Global Impression of Severity. The coincidence in severity level (mild, moderate, severe) of at least two clinical classifications plus the patient's gradation was considered "the criterion of severity". Cut-off values for each MDS-UPDRS subscale was determined by triangulation of: 1) percentile 90 of the subscale total score; 2) receiver operating characteristic (ROC) analysis; and 3) ordinal logistic regression (OLR) model.

RESULTS

Sample was composed of 452 consecutive PD patients without dementia, 55.3% males, age 65.1 ± 10.7 years and PD duration 8.7 ± 6.3 years. All HY stages were represented. The "criterion", classified 275 patients (60.8% of the sample) as: mild PD, 149 (54.2%); moderate, 82 (29.8%); and severe, 44 (16%). The following MDS-UPDRS cut-off points between mild/moderate and moderate/severe levels were found: Part 1: 10/11 and 21/22; Part 2: 12/13 and 29/30; Part 3: 32/33 and 58/59; and Part 4: 4/5 and 12/13.

CONCLUSION

Cut-off points to classify PD patients as mild, moderate, or severe on the basis of their MDS-UPDRS scores are proposed.

Cardiovascular variability in Mexican patients with Parkinson's disease

Cardiovascular variability (CVV) has been evaluated in patients with Parkinson's disease (PD) in other countries and exhibit ethnic differences. Objective We investigated heart rate variability (HRV) and blood pressure variability (BPV) in Mexican patients with PD. Method We further compared HRV and BPV between this group and young healthy controls (YHC) in order to estimate, for the first time in our country, the magnitude of the difference. Twenty patients were examined. Time- and frequency-domain CVV parameters were studied during supine rest (SR), active standing (AS) and controlled breathing. These measurements were compared to those of 20 YHC. Results In the three conditions tested, our study showed a decrease in almost all HRV parameters in PD patients; on the contrary, decreased BPV parameters were found less frequently and only during SR and AS. Conclusion Our results indicate that HRV is impaired in PD. Some BPV parameters are also diminished.

Low specificity and sensitivity of smell identification testing for the diagnosis of Parkinson's disease

OBJECTIVE

The aim of this study is to determine if the University of Pennsylvania's Smell Identification Test (UPSIT) is an accurate diagnostic tool for olfactory dysfunction in Parkinson's disease (PD).

METHOD

We included 138 non-demented PD subjects and 175 control subjects matched by gender. Smell identification was tested using UPSIT.

RESULTS

The mean number of UPSIT items correctly identified by controls was 27.52 ± 5.88; the mean score for PD subjects was 19.66 ± 6.08 (p=<0.001). UPSIT sensitivity was 79.7% with a specificity of 68.5% using a cut-off score of ≤ 25. The overall accuracy for the diagnosis of PD was of 75.3%.

CONCLUSION

UPSIT accuracy and specificity were lower than what has been previously reported. Our data demonstrates that 17.5% of items of the UPSIT were not well identified by healthy controls. Further research of the identification of a truly cross-cultural test is warranted.