Validation of the Freezing of Gait Questionnaire in patients with Parkinson's disease treated with deep brain stimulation.

BACKGROUND: The Freezing of Gait Questionnaire (FoG-Q) is a fast and sensitive assessment tool for freezing (FoG). OBJECTIVE: The objective of the study is for validation of a Czech version of FoG-Q. A further, explorative aim was to examine what FoG-Q indicates about the presence and severity of gait impairment in patients treated with DBS in their full OFF state. DESIGN: The study was a cross-sectional validation study. METHODS: We translated FoG-Q following standardized validation protocol. We assessed 35 patients with PD and STN DBS using history taking, UPDRS, Hoehn and Yahr staging, Mini Mental State Examination, Frontal Assessment Battery, FoG-Q, Short Falls Efficacy Scale International, and Beck Depression Inventory, Second Edition. UPDRS III, clinical and instrumental gait assessment, was repeated OFF MED/DBS OFF and OFF MED/DBS ON. RESULTS: Internal consistency of FoG-Q was excellent (α = 0.91) as well as convergent (significant correlations with UPDRS II item 14, UPDRS III item 29, several TUG parameters, and FoG Score) and divergent validity (no association with UPDRS I). OFF MED/DBS OFF, the total FoG-Q score correlated with UPDRS III items 29, 30, and PIGD subscore, step time variability, and negatively with step length and velocity. LIMITATIONS: Limitation of the study is a relatively small sample size. CONCLUSIONS: In conclusion, the Czech translation of FoG-Q is valid. With respect to gait and balance, FoG-Q does, to a certain extent, reflect the native state of the disease in patients treated with high frequency STN DBS.

Pavement patterns can be designed to improve gait in Parkinson's disease patients.

BACKGROUND: Public spaces are usually designed with respect to various patient populations, but not Parkinson's disease. The objective of this study was to explore what type of easily applicable visual cueing might be used in public spaces and some interiors to improve gait in people with Parkinson's disease. METHODS: Thirty-two patients with freezing of gait walked an 8-meter track on 6 different floor patterns in single- and dual-task conditions in random sequence. The reference pattern was a virtual large transverse chessboard, and the other patterns differed either in size (small floor stones), orientation (diagonal), nature (real paving), regularity (irregular), or no pattern. Time, number of steps, velocity, step length, cadence, and dual-task effect were calculated. The number and total duration of freezing episodes were analyzed. RESULTS: Virtual, large, transverse floor stones improve time (P = 0.0101), velocity (P = 0.0029), number of steps (P = 0.0291), and step length (P = 0.0254) in Parkinson's disease patients compared with walking on no pattern. Virtual floor stones were superior in time and velocity to the real ones. Transverse floor stones were better than diagonal, whereas regular pattern stones were superior to irregular in some gait parameters. Subjectively, the reference pattern was preferred to the irregular one and to no pattern. No direct effect on freezing of gait was observed. CONCLUSIONS: Parkinson's disease patients may benefit from floor patterns incorporating transverse oriented large rectangular visual cues. Because public space can be regulated with respect to people with medical conditions, the relevant legislative documents should be extended to allow for parkinsonian gait disorder. © 2019 International Parkinson and Movement Disorder Society.

Methanol Poisoning as an Acute Toxicological Basal Ganglia Lesion Model: Evidence from Brain Volumetry and Cognition.

BACKGROUND: Acute methanol poisoning leads to optic neuropathy and necrotic lesions of basal ganglia (BG) and subcortical white matter. Survivors of methanol poisoning exhibit long-term executive and memory deficits. Associations between brain volumetry parameters and cognitive sequelae of methanol poisoning are not known. The aim of our study was to identify long-term associations between the cognitive performance of survivors of methanol poisoning and the volume of the brain structures that are selectively vulnerable to methanol. METHODS: We conducted a cross-sectional follow-up study on a sample of patients (n = 33, age 50 ± 14 years, 82% males) who survived acute methanol poisoning during methanol mass poisoning outbreak from September 2012 till January 2013 in the Czech Republic. A battery of neuropsychological tests and brain magnetic resonance imaging were included in the clinical examination protocol. Specific brain structures (putamen, globus pallidus, nucleus caudatus, and frontal white matter) were selected as regions of interest, and their volumes were estimated using the MorphoBox prototype software. RESULTS: In robust multiple regression models, sustained visual attention performance (as assessed by Trail Making Test and Prague Stroop Test) was positively associated with BG structures and frontal white matter volumes (Wald = 9.03 to 85.50, p < 0.01), sensitivity to interference (as assessed by Frontal Battery Assessment) was negatively associated with frontal white matter volume (Wald = 35.44 to 42.25, p < 0.001), and motor performance (as assessed by Finger Tapping Test) was positively associated with globus pallidus and frontal white matter volumes (Wald = 9.66 to 13.29, p < 0.01). CONCLUSIONS: Our results demonstrate that smaller volumes of elements of BG-thalamocortical circuitry, namely the BG and frontal white matter, relate to attention and motor performance in methanol poisoning from a long-term perspective. Disruption of those functional circuits may underlie specific cognitive deficits observed in methanol poisoning.

Reshaping cortical activity with subthalamic stimulation in Parkinson's disease during finger tapping and gait mapped by near infrared spectroscopy.

Exploration of motor cortex activity is essential to understanding the pathophysiology in Parkinson's Disease (PD), but only simple motor tasks can be investigated using a fMRI or PET. We aim to investigate the cortical activity of PD patients during a complex motor task (gait) to verify the impact of deep brain stimulation in the subthalamic nucleus (DBS-STN) by using Near-Infrared-Spectroscopy (NIRS). NIRS is a neuroimaging method of brain cortical activity using low-energy optical radiation to detect local changes in (de)oxyhemoglobin concentration. We used a multichannel portable NIRS during finger tapping (FT) and gait. To determine the signal activity, our methodology consisted of a pre-processing phase for the raw signal, followed by statistical analysis based on a general linear model. Processed recordings from 9 patients were statistically compared between the on and off states of DBS-STN. DBS-STN led to an increased activity in the contralateral motor cortex areas during FT. During gait, we observed a concentration of activity towards the cortex central area in the "stimulation-on" state. Our study shows how NIRS can be used to detect functional changes in the cortex of patients with PD with DBS-STN and indicates its future use for applications unsuited for PET and a fMRI.

Imaging findings after methanol intoxication (cohort of 46 patients).

OBJECTIVES: Our goal is to demonstrate the variability of imaging findings, primarily in the MRI, in 46 patients who survived acute methanol poisoning. This cohort of patients is the largest such sample group examined by MRI. METHODS: Patients were examined by means of imaging methods (42 patients by MRI and 4 by CT). All had an identical protocol of MR examination (T2WI, FLAIR, T1WI with or without application of contrast medium and T2WI/FFE, DWI in the transversal plane of the scan, and with focus on the optic nerves in the coronal plane of the scan in T2WI-SPIR). RESULTS: Imaging methods revealed a positive finding associated with methanol intoxication in 21 patients (46%). These consisted of symmetrical lesions in the putamen--13 patients (28%), haemorrhage--13 cases (28%), deposits in white matter with localization primarily subcortically--4 cases (9%), lesions in the region of the globus pallidus--7 cases (15%) (in 6 cases without combination with the lesions in the putamen), lesions in the brainstem afflicted 6 patients (13%), and lesion in the cerebellum was found in one case. A pathological finding was found only in the patients examined by MRI. CONCLUSION: Almost half of the patients who survived acute methanol poisoning had pathological findings by MRI. The most common finding concerned an affliction of the putamen, which is a predilection area. An interesting finding was the relatively frequent occurrence of selective lesion of the globus pallidus, which is more usually associated with other types of intoxication.

A distinct variant of mixed dysarthria reflects parkinsonism and dystonia due to ephedrone abuse.

A distinctive alteration of speech has been reported in patients suffering from ephedrone-induced parkinsonism. However, an objective assessment of dysarthria has not been performed in ephedrone users. We studied 28 young Caucasian men from Georgia with a previous history of ephedrone abuse and compared them to 25 age-matched healthy controls. Speech examination, brain MRI, and NNIPPS-Parkinson plus scale were performed in all patients. The accurate differential diagnosis of dysarthria subtypes was based on the quantitative acoustic analyses of 15 speech dimensions. We revealed a distinct variant of mixed dysarthria with a combination of hyperkinetic and hypokinetic components representing the altered motor programming of dystonia and bradykinesia in ephedrone-induced parkinsonism. According to acoustic analyses, all patients presented at least one affected speech dimension, whereas dysarthria was moderate in 43% and severe in 36% of patients. Further findings indicated relationships between motor subscores of dystonia and bradykinesia and speech components of loudness (r = -0.54, p < 0.01), articulation (r = 0.40, p < 0.05), and timing (r = -0.53, p < 0.01). In ephedrone-induced parkinsonism a prominent mixed hyperkinetic-hypokinetic dysarthria occurs that appears related to marked dystonia and bradykinesia and probably reflects manganese induced toxic and neurodegenerative damage to the globus pallidus internus and substantia nigra.

Changes of hand preference in Parkinson's disease.

This study focused on the difference between pre-morbid and current hand preference of patients with Parkinson's disease (PD). A survey instrument comprised items measuring pre-morbid and current hand preference and question related to the side of occurrence of initial symptoms. These questions were administered to 471 PD patients. The results show a significant change of pre-morbid right hand preference toward using the left when the side of PD onset was on the right hand and vice versa. Disease duration does not predict the amount of hand preference shift.

Long-Term Averaged Spectrum Descriptors of Dysarthria in Patients With Parkinson's Disease Treated With Subthalamic Nucleus Deep Brain Stimulation.

PURPOSE: This study aimed to evaluate whether long-term averaged spectrum (LTAS) descriptors for reading and monologue are suitable to detect worsening of dysarthria in patients with Parkinson's disease (PD) treated with subthalamic nucleus deep brain stimulation (STN-DBS) with potential effect of ON and OFF stimulation conditions and types of connected speech. METHOD: Four spectral moments based on LTAS were computed for monologue and reading passage collected from 23 individuals with PD treated with bilateral STN-DBS and 23 age- and gender-matched healthy controls. Speech performance of patients with PD was compared in ON and OFF STN-DBS conditions. RESULTS: All LTAS spectral moments including mean, standard deviation, skewness, and kurtosis across both monologue and reading passage were able to significantly distinguish between patients with PD in both stimulation conditions and control speakers. The spectral mean was the only LTAS measure sensitive to capture better speech performance in STN-DBS ON, as compared to the STN-DBS OFF stimulation condition (p < .05). Standardized reading passage was more sensitive compared to monologue in detecting dysarthria severity via LTAS descriptors with an area under the curve of up to 0.92 obtained between PD and control groups. CONCLUSIONS: Our findings confirmed that LTAS is a suitable approach to objectively describe changes in speech impairment severity due to STN-DBS therapy in patients with PD. We envisage these results as an important step toward a continuum development of technological solutions for the automated assessment of stimulation-induced dysarthria. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.21644798.

Short- and Long-Term Effects of DBS on Gait in Parkinson's Disease.

The aim was to compare the short and long-term effects of subthalamic nucleus (STN) deep brain stimulation (DBS) on gait dysfunction and other cardinal symptoms of Parkinson's disease (PD). Two groups of patients were studied. The first group (short-term DBS, n = 8) included patients recently implanted with STN DBS (mean time since DBS 15.8 months, mean age 58.8 years, PD duration 13 years); the second group (long-term DBS, n = 10) included patients with at least 5 years of DBS therapy (mean time since DBS 67.6 months, mean age 61.7 years, PD duration 17.1 years). Both groups were examined using the Unified Parkinson's Disease Rating Scale (UPDRS) and Gait and Balance scale (GABS) during four stimulation/medication states (ON/OFF; OFF/OFF; OFF/ON; ON/ON). Data were analyzed using repeated measures ANOVA with time since implantation (years) between groups and medication or DBS effect (ON, OFF) within groups. In the short-term DBS group, stimulation improved all UPDRS subscores similar to dopaminergic medications. In particular, average gait improvement was over 40% (p = 0.01), as measured by the UPDRS item 29 and GABS II. In the long-term DBS group, stimulation consistently improved all clinical subscores with the exception of gait and postural instability. In these patients, the effect of levodopa on gait was partially preserved. Short-term improvement of gait abnormalities appears to significantly decline after 5 years of STN DBS in PD patients, while effectiveness for other symptoms remains stable. Progressive non-dopaminergic (non-DBS responsive) mechanisms or deleterious effects of high frequency STN stimulation on gait function may play a role.

Cognitive changes after methanol exposure: Longitudinal perspective.

BACKGROUND: From 2012 to 2013, there was a mass methanol poisoning outbreak in the Czech Republic. Methanol metabolites can cause specific lesions in the basal ganglia, subcortical white matter, and optic nerve. However, long-term sequelae of methanol poisoning on cognitive functioning have not yet been explored. The current study aimed to delineate the cognitive changes observed in methanol poisoning survivors in the seven years since 2012. METHODS: We conducted longitudinal research with repeated measurements in 2013, 2015, 2017 and 2019 to evaluate the development of cognitive changes after acute methanol poisoning. A complex neuropsychological battery consisted of tests of global cognitive performance, auditory and visual attention, executive functioning, learning and memory, working memory and language. Motor performance measures and depression scale were also included. RESULTS: Repeated measures ANOVA of four measurements with post-hoc tests showed a significant decline in the Mini-Mental State Examination (p = 0.007); however, other parameters were not significantly decreasing. In comparison to normative values, the z-scores for each test measure, in the memory domain, in particular, ranged from 43 to 60 % of participants below 1.5 SD. Mild to severe depression levels from the onset of poisoning improved during the seven years, returning to normal in up to 27 % of participants. CONCLUSION: In the longitudinal perspective, methanol poisoning survivors manifest progressive global cognitive decline and overall persistent below-average cognitive performance with some improvements in the frequency of depressive symptoms.

Efficiency of 123I-ioflupane SPECT as the marker of basal ganglia damage in acute methanol poisoning: 6-year prospective study.

CONTEXT: Investigate whether 123I-ioflupane SPECT (DaT SPECT) has the potential as a marker of basal ganglia damage in acute methanol poisoning. METHODS: Prospective, single-centre, cohort study of patients with confirmed methanol poisoning was conducted. DaT SPECT was performed twice with semi-quantification using DaTQUANTTM and MRI-based volumetry was calculated. Specific binding ratios (SBR) of striatum, caudate nucleus, and putamen were correlated with laboratory parameters of outcome, volumetric data, and retinal nerve fibres layer (RNFL) thickness measurements. RESULTS: Forty-two patients (mean age 46.3 ± 4.2 years; 8 females), including 15 with MRI-detected putamen lesions (group I) and 27 patients with intact putamen (group II), underwent DaT SPECT. Volumetry was calculated in 35 of the patients assessed. SBR values for the left putamen correlated with putamen volume (r = 0.665; p < 0.001). Decreased bilateral SBR values were determined for the striatum and the putamen, but not for the nucleus caudate, in group I (p < 0.05). Significant correlation was observed between the SBR of the posterior putamen and arterial blood pH (r = 0.574; p < 0.001) and other toxicological parameters of severity of poisoning/outcome including serum lactate, glucose, and creatinine concentrations (p < 0.05). The SBR of the posterior putamen positively correlated with the global RNFL thickness (p < 0.05). ROC analysis demonstrated a significant discriminatory ability of SBR of the posterior putamen with AUC = 0.753 (95%CI 0.604-0.902; p = 0.007). The multivariate regression model demonstrated that arterial blood pH, age, and gender were the most significant factors associated with SBR of the posterior putamen. CONCLUSION: DaT SPECT demonstrates significant potential for the diagnosis of methanol-induced basal ganglia damage.

3D visual cueing shortens the double support phase of the gait cycle in patients with advanced Parkinson's disease treated with DBS of the STN.

BACKGROUND: Gait disturbances have emerged as some of the main therapeutic concerns in late-stage Parkinson's disease (PD) treated with dopaminergic therapy and deep brain stimulation (DBS). External cues may help to overcome freezing of gait (FOG) and improve some of the gait parameters. AIM: To evaluate the effect of 3D visual cues and STN-DBS on gait in PD group. METHODS: We enrolled 35 PD patients treated with DBS of nucleus subthalamicus (STN-DBS). Twenty-five patients (5 females; mean age 58.9 ±6.3) and 25 sex- and age-matched controls completed the gait examination. The gait in 10 patients deteriorated in OFF state. The severity of PD was evaluated using the Unified Parkinson's Disease Rating Scale (UPDRS) and Hoehn and Yahr (HY). The PD group filled the Falls Efficacy Scale-International (FES) and Freezing of Gait Questionnaire (FOGQ). Gait was examined using the GaitRite Analysis System, placed in the middle of the 10m marked path. The PD group was tested without dopaminergic medication with and without visual cueing together with the DBS switched ON and OFF. The setting of DBS was double-blind and performed in random order. RESULTS: The UPDRS was 21.9 ±9.5 in DBS ON state and 41.3 ±13.7 in DBS OFF state. HY was 2.5 ±0.6, FES 12.4 ±4.1 and FOGQ 9.4 ±5.7. In the DBS OFF state, PD group walked more slowly with shorter steps, had greater step length variability and longer duration of the double support phase compared to healthy controls. The walking speed and step length increased in the DBS ON state. The double support phase was reduced with 3D visual cueing and DBS; the combination of both cueing and DBS was even more effective. CONCLUSION: Cueing with 3D visual stimuli shortens the double support phase in PD patients treated with DBS-STN. The DBS is more effective in prolonging step length and increasing gait speed. We conclude that 3D visual cueing can improve walking in patients with DBS.

Agreement between the GAITRite® System and the Wearable Sensor BTS G-Walk® for measurement of gait parameters in healthy adults and Parkinson's disease patients.

BACKGROUND: Nowadays, the most widely used types of wearable sensors in gait analysis are inertial sensors. The aim of the study was to assess the agreement between two different systems for measuring gait parameters (inertial sensor vs. electronic walkway) on healthy control subjects (HC) and patients with Parkinson's disease (PD). METHODS: Forty healthy volunteers (26 men, 14 women, mean age 58.7 ± 7.7 years) participated in the study and 24 PD patients (19 men, five women, mean age 62.7 ± 9.8 years). Each participant walked across an electronic walkway, GAITRite, with embedded pressure sensors at their preferred walking speed. Concurrently a G-Walk sensor was attached with a semi-elastic belt to the L5 spinal segment of the subject. Walking speed, cadence, stride duration, stride length, stance, swing, single support and double support phase values were compared between both systems. RESULTS: The Passing-Bablock regression slope line manifested the values closest to 1.00 for cadence and stride duration (0.99 ≤ 1.00) in both groups. The slope of other parameters varied between 0.26 (double support duration in PD) and 1.74 (duration of single support for HC). The mean square error confirmed the best fit of the regression line for speed, stride duration and stride length. The y-intercepts showed higher systematic error in PD than HC for speed, stance, swing, and single support phases. CONCLUSIONS: The final results of this study indicate that the G-Walk system can be used for evaluating the gait characteristics of the healthy subjects as well as the PD patients. However, the duration of the gait cycle phases should be used with caution due to the presence of a systematic error.

Lack of Accredited Clinical Training in Movement Disorders in Europe, Egypt, and Tunisia.

BACKGROUND: Little information is available on the official postgraduate and subspecialty training programs in movement disorders (MD) in Europe and North Africa. OBJECTIVE: To survey the accessible MD clinical training in these regions. METHODS: We designed a survey on clinical training in MD in different medical fields, at postgraduate and specialized levels. We assessed the characteristics of the participants and the facilities for MD care in their respective countries. We examined whether there are structured, or even accredited postgraduate, or subspecialty MD training programs in neurology, neurosurgery, internal medicine, geriatrics, neuroradiology, neuropediatrics, and general practice. Participants also shared their suggestions and needs. RESULTS: The survey was completed in 31/49 countries. Structured postgraduate MD programs in neurology exist in 20 countries; structured neurology subspecialty training exists in 14 countries and is being developed in two additional countries. Certified neurology subspecialty training was reported to exist in 7 countries. Recommended reading lists, printed books, and other materials are the most popular educational tools, while courses, lectures, webinars, and case presentations are the most popular learning formats. Mandatory activities and skills to be certified were not defined in 15/31 countries. Most participants expressed their need for a mandatory postgraduate MD program and for certified MD sub-specialization programs in neurology. CONCLUSION: Certified postgraduate and subspecialty training exists only in a minority of European countries and was not found in the surveyed Egypt and Tunisia. MD training should be improved in many countries.

Handedness does not predict side of onset of motor symptoms in Parkinson's disease.

This study focused on the relationship between the asymmetry of initial motor symptoms of Parkinson's disease (PD) and premorbid handedness of patients. Structural equation modeling has been used for this purpose. The survey consisting of validated items measuring handedness and questions related to side of occurrence of initial symptoms was administered to 472 patients with PD [277 men, 195 women, mean age 66.5 (9.3), mean duration of the disease 10 (6.1) years]. The unidimensional model of handedness fits the data well (chi(2) = 37.86, df = 20, P = 0.009, Root Mean Square Error of Approximation = 0.044, Comparative Fit Index = 1.00, Standardized Root Mean Square Residual = 0.042) and side of initial motor symptoms is not significantly related to the factor of handedness (r =0.11, SE = 0.07, P = 0.14). In contrast to several other studies, the results indicate that the side of first occurrence of PD signs cannot be predicted from premorbid handedness of patients.

Fear of falling has greater influence than other aspects of gait disorders on quality of life in patients with Parkinson's disease.

We assessed the influence of gait disorders (GD) on quality of life (QOL) in Parkinson's disease (PD). In a survey including the PDQ-39 and a new 8-item questionnaire of GD (8-QGD), 491 PD patients estimated their gait at the worst state, the effect of their GD on activities of daily living, compared the severity of GD with the other PD symptoms, evaluated the occurrence of freezing of gait (FOG), levodopa-resistant FOG, falls, activity limitation due to fear of falling (FOF), and the occurrence of injuries. Significant differences in PDQ-39 scores were found between three groups of patients divided with respect to the severity of GD. Linear multiple regression analysis showed that FOF had the highest impact on PDQ-39 scores (r=0.32, p<0.001). These results confirm that GD have a substantial impact upon the QOL in PD and suggest that FOF plays a major role in QOL deterioration.

On the structure of motor symptoms of Parkinson's disease.

This study aims to investigate the structure of the motor symptoms of Parkinson's disease (PD), as measured by the Motor Section of the Unified Parkinson's Disease Rating Scale (UPDRS). The dimensionality of the Motor Section of the UPDRS was studied using structural equation modeling. The UPDRS measures were obtained from 405 patients with PD [237 men (39 "off", 170 "on", 28 unknown) and 168 women (21 "off", 140 "on", 7 unknown)]. The ordinal character of UPDRS scores and sample size substantiated the use of robust diagonally weighted least squares model estimation. It was shown that the Motor Section of the UPDRS incorporates five main latent symptom factors (rigidity, tremor, bradykinesia of the extremities, axial/gait bradykinesia, speech/hypomimia) plus two additional factors for laterality, which account for asymmetry of tremor, rigidity and bradykinesia of the extremities. Tremor seems to be an independent symptom factor of PD. Other latent variables are substantially correlated.

Push-and-release test predicts Parkinson fallers and nonfallers better than the pull test: comparison in OFF and ON medication states.

The aim of this study was to compare the Pull Test--Retropulsion Test and the Push and Release Test (P&R) as regards their ability to predict Parkinson (PD) fallers and nonfallers in relation to their medication state. Eighty-two PD patients participated in the study. Fallers (N = 36) and nonfallers (N = 46) were grouped on the basis of their fall history. Fallers were those who had fallen at least once within the last 6 months. The two groups were compared on the basis of the patients' performance in the Pull and the P&R tests, both in their "OFF" and "ON" medication state. The overall accuracy of the classification of PD patients as fallers and nonfallers was determined by means of binomial logistic regression (BLR) and the analysis of the "area under the receiver operating characteristics curve" (AUC). In the OFF medication state, the statistical analysis revealed that the Pull Test was accurate (methods BLR (AUC)) in 85.4% (0.87) of cases and the P&R Test in 86.6% (0.90). In the ON medication state, the Pull Test was only 76.8% (0.78) accurate, while the P&R Test was 87.8% (0.87) accurate. Both clinical tests are valid and relatively equivalent when assessing patients in their OFF medication state; however, the P&R Test is more accurate than the Pull Test in the ON state. This indicates that it is more widely applicable in clinical practice.

Mokken scale analysis of the UPDRS: dimensionality of the Motor Section revisited.

The dimensionality and reliability of the Motor Section of the Unified Parkinson Disease Rating Scale (UPDRS III) was studied with non-parametric Mokken scale analysis. UPDRS measures were obtained on 147 patients with PD (96 men, 51 women, mean age 61, range 35-80 yrs). Mokken scale analysis revealed a four-dimensional structure of the UPDRS III. Left-sided bradykinesia and rigidity appeared to co-occur with axial signs, gait disturbance, and speech/hypomimia, whereas right-sided bradykinesia and rigidity formed a second scale. Two further small scales were found consisting of right- and left-sided tremor. Results from the scale analysis reveal that all four subscales are strong. The reliability of the two tremor scales is low because they only contain three and four items, respectively.