Change in Static Postural Stability after a Home‑based Exercise Program in Persons with Idiopathic Parkinson’s Disease - A Randomized Control Study

Introduction and Purpose:The most common form of parkinsonism is idiopathic Parkinson’s disease. The cardinal symptoms of idiopathicParkinson’s disease are tremor, rigidity, bradykinesia, posture and gait abnormalities, speech changes, depression, gastrointestinal issues,urinary problems, autonomic features, eye abnormalities, cognitive impairments, cranial nerve dysfunction, and swallowing dysfunction.Abnormalities of posture significantly affect activities of daily living in such patients. Static posturography is used to measure the balanceof an individual during standing. Asingle-blinded controlled trial comparing 4 weeks of outpatient physical therapy with no specific therapyshowed significant improvement in gait in patients with Parkinson’s disease. However, the gains were lost when the patients stoppedexercises at the end of the program. Hence, the authors felt that teaching a simple, implementable home-based exercise could benefitthese patients in improving their balance. Any change in static balance could be measured easily with a force platform.Methodology: A total of 62 clinically diagnosed patients with idiopathic Parkinson’s disease attending a tertiary care centerwere randomized into two groups, one rehabilitation group (those who were taught a simple home-based rehabilitation exerciseprogram on an outpatient basis) and a non-rehabilitation (control) group who were not taught the exercises. They were clinicallyevaluated and their center of pressure (COP) sway area was measured using a computerized static posturography instrument(force platform), at first visit, after 1 month, after 3 months, and after 5 months. The differences in their COP sway area betweenthe visits were compared between the two groups to see the change in postural stability.Results and Discussion: Atotal of 62 patients who satisfied the inclusion criteria were inducted in the study after informed consent. Themean age of the rehabilitation group (n = 32) was 58.66 years and the mean age of the non-rehabilitation group (n = 30) was 59.17 years.69% of the rehabilitation group were males and 31% were females, and in the non-rehabilitation group, 67% were males while 37%were females. The mean duration of disease in the rehabilitation group was 8.31 years and that in the non-rehabilitation group was8.67 years. Most of the variables did not show any significant difference, and hence, the groups were comparable. The baseline meanCOP sway area of the rehabilitation group was 76.53 mm2 and that of the non-rehabilitation group was 76.73 mm2. There was a 11.68%decrease in the COP sway area of the rehabilitation group at the end of the 1st month while the non-rehabilitation group had only 0.22%decrease. At the end of the study, i.e., at 5th month, there was a 32.05% decrease in the sway area from baseline in the rehabilitationgroup, indicating significant improvement in static balance. There was only 1.13% decrease in the sway area of the non-rehabilitationgroup. Both the P values were <0.001, and thus, our study revealed that a simple home-based rehabilitation exercise program taughton an outpatient basis to patients with idiopathic Parkinson’s disease can improve the balance in such patients.Conclusion: There was a statistically significant improvement in the static postural stability of patients with idiopathic Parkinson’sdisease who did exercise at home when compared to those who did not perform the home-based exercises. However, longterm studies need to be done to confirm whether this gain is long lasting.

Utility of the Midbrain Tegmentum Diameter in the Differential Diagnosis of Progressive Supranuclear Palsy from Idiopathic Parkinson's Disease

BACKGROUND AND PURPOSE: Various magnetic resonance (MR) measurements have been proposed to aid in differentiating between progressive supranuclear palsy (PSP) and idiopathic Parkinson's disease (IPD); however, these methods have not been compared directly. The aim of this study was to determine which measurement method exhibits the highest power to differentiate between PSP and IPD. METHODS: Brain MR images from 82 IPD and 29 PSP patients were analyzed retrospectively. T1-weighted 3D volumetric axial images, or sagittal images reconstructed from those axial images were examined. MR measurements included the length from the interpeduncular fossa to the center of the cerebral aqueduct at the mid-mammillary-body level, adjusted according to the anterior commissure-posterior commissure length (MB(Tegm)), the ratio of the midbrain area to the pons area (M/P ratio) as measured by both Oba's method (Oba M/P) and Cosottini's method (Cosottini M/P), and a modified MR parkinsonism index (mMRPI). RESULTS: Receiver operating characteristic (ROC) analysis indicated that the areas under the ROC curves (AUCs) exceeded 0.70, with a high intrarater reliability for all MR measurement methods. ROC analyses of four MR measurements yielded AUCs of 0.69-0.76. At the cutoff value with the highest Youden index, mMRPI had the highest sensitivity, while Oba M/P offered the highest specificity. A comparison of the ROC analyses revealed that MB(Tegm) was superior to mMRPI in differentiating PSP from IPD (p=0.049). There was no difference in discriminating power among Oba M/P, Cosottini M/P, and MB(Tegm). CONCLUSIONS: Simple measurements of MB(Tegm) on axial MR images at the mid-mammillary-body level are comparable to measurements of the M/P ratio with regard to their ability to discriminate PSP from IPD.

Delayed latencies of auditory evoked potential P300 are associated with the severity of Parkinson's disease in older patients / O atraso das latências do potencial evocado auditivo P300 está associado à gravidade da doença de Parkinson em pacientes mais velhos

Electrophysiological methods could provide important information about the neurophysiological status in Parkinson's disease (PD). Objective: To investigate the prolonged auditory P300 latency in PD and its association with the disease clinical stage. Method: Clinical profiles of 44 patients were evaluated and those in initial and advanced stages of PD were identified. The frequency of altered latencies, median of latencies in each stage, and correlation between latencies and motor and non-motor clinical features were analyzed. Latencies were considered altered when they were more than two standard deviations from the mean of controls, per age group. Results: It was verified 10% of alterations in initial stages and 31% in advanced. There was correlation between latencies and non-motor clinical features. Subjects older than 65, in advanced stages, presented a significant increase of latencies. Conclusion: There was an association between PD severity and P300 prolonged latencies among subjects 65 years old or older. .

Exames eletrofisiológicos podem fornecer informações sobre o status neurofisiológico na doença de Parkinson (DP). Objetivo: Investigar o prolongamento das latências do P300 auditivo na DP e sua associação com o estágio da doença. Método: Foi avaliado o quadro clínico de 44 pacientes e identificados aqueles em estágio inicial e avançado da DP. Analisou-se a frequência de latências alteradas, mediana das latências em cada estágio e a correlação entre latências e quadro clínico motor e não motor da DP. As latências foram consideradas alteradas quando superiores a dois desvios-padrão da média dos controles, por grupo etário. Resultados: Verificaram-se 10% de alterações no estágio inicial e 31% no avançado. Houve correlação entre as latências e o quadro clínico não motor. Sujeitos com mais de 65 anos, em estágio avançado, apresentaram significativo aumento das latências. Conclusão: Existe associação entre gravidade da DP e prolongamento das latências do P300 nos sujeitos acima de 65 anos. .

Executive dysfunction and motor symptoms in Parkinson's disease / Disfunções executivas e sintomas motores na doença de Parkinson

The aim of this study is to analyze executive function and motor symptoms in patients with idiopathic Parkinson's disease (PD). The sample consisted of 44 subjects with PD between the ages of 45 to 75, who were examined consecutively. The subjects were divided into two groups according to the duration of the disease. The control group was composed of spouses, family and accompanying members. Patients included were submitted to motor dysfunction evaluation using the UPDRS. The executive functions modalities analyzed included: operational memory, inhibitory control, planning, cognitive flexibility and inductive reasoning. Significant differences between the experimental and control groups were found in all the executive domains studied. Evidence of tremor, rigidity and bradykinesia correlation with executive dysfunction were not observed. Patients with PD, even in the initial phase of the disease, presented executive dysfunction. The cardinal motor signs of the disease were not correlated with the cognitive dysfunction found.

O objetivo do estudo é avaliar as funções executivas e sintomas motores em pacientes portadores de doença de Parkinson. A amostra se constituiu de 44 portadores de doença de Parkinson com idade entre 45 e 75 anos, examinados consecutivamente, os quais foram divididos em dois grupos de acordo com o tempo de duração da doença. O grupo controle foi composto de acompanhantes ou cônjuges. Os sujeitos selecionados foram submetidos à avaliação motora utilizando-se a escala UPDRS e à avaliação das funções executivas nas modalidades: raciocínio indutivo, memória operacional, controle inibitório, planejamento e flexibilidade cognitiva. Os resultados apontaram diferenças significantes entre os grupos experimentais e controle nas modalidades analisadas. Não encontramos evidência de associação entre tremor, rigidez e bradicinesia com as funções executivas. Conclui-se que os pacientes com doença de Parkinson, mesmo nas fases iniciais da doença, apresentam comprometimento cognitivo executivo. Os sintomas motores da doença não estavam correlacionados às disfunções executivas.

Evaluation of Multiple System Atrophy and Early Parkinson's Disease Using (123)I-FP-CIT SPECT / 핵의학분자영상

PURPOSE: We investigated quantification of dopaminergic transporter (DAT) and serotonergic transporter (SERT) on (123)I-FP-CIT SPECT for differentiating between multiple systemic atrophy (MSA) and idiopathic Parkinson's disease (IPD). MATERIALS AND METHODS: N-fluoropropyl-2beta-carbomethoxy-3beta-4-[(123)I]-iodophenylnortropane SPECT ((123)I-FP-CIT SPECT) was performed in 8 patients with MSA (mean age: 64.0+/-4.5yrs, m:f=6:2), 13 with early IPD (mean age: 65.5+/-5.3yrs, m:f=9:4), and 12 healthy controls (mean age: 63.3+/-5.7yrs, m:f=8:4). Standard regions of interests (ROIs) of striatum to evaluate DAT, and hypothalamus and midbrain for SERT were drawn on standard template images and applied to each image taken 4 hours after radiotracer injection. Striatal specific binding for DAT and hypothalamic and midbrain specific binding for SERT were calculated using region/reference ratio based on the transient equilibrium method. Group differences were tested using ANOVA with the postHoc analysis. RESULTS: DAT in the whole striatum and striatal subregions were significantly decreased in both patient groups with MSA and early IPD, compared with healthy control (p<0.05 in all). In early IPD, a significant increase in the uptake ratio in anterior and posterior putamen and a trend of increase in caudate to putamen ratio was observed. In MSA, the decrease of DAT was accompanied with no difference in the striatal uptake pattern compared with healthy controls. Regarding the brain regions where (123)I-FP-CIT binding was predominant by SERT, MSA patients showed a decrease in the binding of (123)I-FP-CIT in the pons compared with controls as well as early IPD patients (MSA: 0.22+/-0.1 healthy controls: 0.33+/-0.19, IPD: 0.29+/-0.19), however, it did not reach the statistical significance. CONCLUSION: In this study, the differential patterns in the reduction of DAT in the striatum and the reduction of pontine (123)I- FP-CIT binding predominant by SERT could be observed in MSA patients on (123)I- FP-CIT SPECT. We suggest that the quantification of SERT as well as DAT using (123)I- FP-CIT SPECT is helpful to differentiate parkinsonian disorders in early stage.

Effect of Auditory and Visual Cues on Gait in Patients with Idiopathic Parkinson's Disease

OBJECTIVE: To examine the effects of auditory and visual cues on gait in patients with idiopathic Parkinson's disease (IPD). METHOD: Patients were 16 persons with IPD, and controls were 14 age-matched healthy persons. Controls were allowed to walk at self-selected gait speed and patients walked at no, auditory and visual cues. Gait parameters were gained, and stride variability were measured at each gait trial. RESULTS: In patients, cadence at visual cues was decreased compared with that of controls, no and auditory cues in the statistics. Walking velocity was decreased in all patients than controls, but there was no difference in each cues. Stri-de length at visual cues was increased compared with that of no and auditory cues, and increased to that of controls. Stride variability was decreased at visual cues compared with that of no and auditory cues, and decreased to that of controls. CONCLUSION: With the use of visual cues in patients with IPD, the cadence was decreased but stride length was increased and stride variability was decreased to the level of controls. Thus, visual cues could be one of the useful method for gait training in patients with IPD.

Gait Analysis in Patients with Idiopathic Parkinson's Disease during Obstacle Crossing

OBJECTIVE: To compare gait parameters of patients with idiopathic Parkinson's disease (IPD) during obstacle crossing with those of healthy control subjects. METHOD: Conventional physical examinations and three- dimensional gait analysis were performed on 16 patients of IPD with stage 2~3 of the Hoehn and Yahr disease rating scale, and 11 healthy control subjects during stepping over the obstacle. Temporospatial, kinematic and kinetic parameters of patients were compared with those of the control group. RESULTS: In patients with IPD, walking velocity was slower and stride length were shorter than control group. Decreased post-obstacle distance of the lead limb and increased pre-swing time of the lead and trail limbs were noted in IPD patients compared to control group. Many significant modifications of kinematic and kinetic parameters were detected in IPD patients compared to control group during obstacle crossing. CONCLUSION: Using three-dimensional gait analysis, we could identify specific modifications of gait parameters in IPD patients during obstacle crossing. These modifications may reduce or increase the risk of a falling in IPD patients.

Application of SPM for Comparison of Striatal Dopamine Transporter Density between the Early Stage of the Parkinsonian Variant of Multiple System Atrophy and Parkinson's Disease

OBJECTIVE: Nigrostriatal dopaminergic neuronal degeneration is common to idiopathic Parkinson's disease(PD) and multiple system atrophy(MSA); although the topography of the nigral cell loss and striatal dopamine deficiency may differ. Currently, several functional neuroimaging techniques have been developed to differentiate between these two diseases. However, since the basal ganglia are usually poorly delineated in parkinsonian disorders on most functional neuroimaging techniques, most studies have failed to show the different pathologic changes among the parkinsonian disorders. In this study, we investigated alternation in regional loss of dopamine transporter binding using statistical parametric mapping(SPM) in patients with PD and the parkinsonian variant of MSA(MSA-P). METHODS: Ten PD and five MSA-P patients within 3 years of duration were studied with dual isotope brain SPECT following simultaneous injection of 370 MBq [99mTc] HMPAO and 111 MBq [123I] IPT. RESULTS: The basal ganglia were clearly visible on the fusion image, which was possible for quantitative and sta- tistical analysis. MSA-P patients showed significant loss of dopamine transporter binding in the left globus pallidus, anterior putamen and caudate nucleus in comparison to PD patients. CONCLUSION: This result may provide a useful tool to differentiate the pattern of loss of dopamine transporter bin- ding between PD and MSA-P.

A Case of Idiopathic Parkinson's Disease Combined with Progressive Nonfluent Aphasia

It is not uncommon for idiopathic parkinson's disease (IPD) to occur concurrently with other degenerative dementing disorders such as Alzheimer's disease. However, there has been no report about the comorbidity of IPD and frontotemporal lobar degeneration. We report a 70-year-old man diagnosed with IPD accompanied by progressive non-fluent aphasia (PA). Brain MRI showed left frontal opercular atrophy, and an 18F-FDG PET scan revealed predominant left frontotemporal hypometabolism. It remains unknown whether or not the co-occurrence of IPD and PA was coincidental.

Measurements of Brain Stem and Cerebellum on Brain MRI: for the Differential Diagnosis Between Multiple System Atrophy and Idiopathic Parkinson's Disease

BACKGROUND: Multiple system atrophy (MSA) and idiopathic Parkinson's disease (IPD) are two common neurodegenerative disorders presenting with parkinsonism. Since a brain MRI study is an available method for differentiating MSA from IPD, we tried to find further values of brain MRI studies in differentiating MSA from IPD. METHODS: We measured anteroposterior and transverse diameters (AD and TD, respectively) of the brain stem of T2-weighted axial images. We graded the severity of atrophy (grade 0: none; grade 1: mild; grade 2: moderate; and grade 3: severe) of cerebellar vermis and hemispheres on the midsagittal and parasagittal planes. RESULTS: There were 36 patients with probable MSA and 40 patients with IPD. We calculated a parameter multiplying AD of the midbrain by TD of the midbrain. The mean of the AD x TD of the midbrain was 1007.5 +/- 161.8 mm2 in patients with MSA, and it was significantly smaller than that of those with IPD (1113.3 +/- 118.7 mm2). When the cut off value was decided as 1050 mm2, the sensitivity of the parameter for the diagnosis of MSA was 83.3% and specificity was 80%. The frequency of cerebellar atrophy was 72.2% in patients with MSA, and it was significantly higher than that of those with IPD (37.5%). CONCLUSIONS: Measurements of the brain stem, particularly the midbrain, and cerebellum areas on brain MRI are helpful methods for the differential diagnosis of patients with MSA from those with IPD.

The Effect of Subthalamic Nucleus Stimulation in Patients with Advanced Idiopathic Parkinson's Disease

BACKGROUND: To determine the efficacy and safety of subthalamic nucleus (STN) stimulation in patients with advanced Parkinson's disease (PD). METHODS: In 5 patients with PD, we evaluated the effect of bilateral STN stimula-tion. Using the Unified PD Rating Scale (UPDRS), Clinical Dyskinesia Rating Scale, Activities of Daily Living(ADL) Score and patient's diary, we evaluated the patients before and at one, three and 12 months after surgery. We examined the patients while they were drug "off" and "on". RESULTS: While patients were "off", stimulation induced a signifi-cant reduction in the UPDRS part III score by 46% at 12 months after the operation, compared to the baseline state. During drug "on" state, levodopa-induced dyskinesias were reduced by 88% at 12 months after the operation. Off-peri-od dystonia was reduced by 45% at 12 months after the operation. ADL scores also improved after the stimulation. Patients' diaries showed significant reduction in the "off" period while awake (73% reduction at 12 months). The daily dose of levodopa was reduced by 56% at 12 months after the operation. There was no significant complication related to the surgical procedure or electrical stimulation. CONCLUSIONS: We conclude that STN stimulation is an effective and safe treatment strategy for the patients with advanced PD.

The pedunculopontine nucleus: its role in the genesis of movement disorders

The pedunculopontine nucleus (PPN) is located in the dorso-lateral part of the ponto-mesencephalic tegmentum. The PPN is composed of two groups of neurons: one containing acetylcholine, and the other containing non-cholinergic neurotransmitters (GABA, glutamate). The PPN is connected reciprocally with the limbic system, the basal ganglia nuclei (globus pallidus, substantia nigra, subthalamic nucleus), and the brainstem reticular formation. The caudally directed corticolimbic-ventral striatal-ventral pallidal-PPN-pontomedullary reticular nuclei-spinal cord pathway seems to be involved in the initiation, acceleration, deceleration, and termination of locomotion. This pathway is under the control of the deep cerebellar and basal ganglia nuclei at the level of the PPN, particularly via potent inputs from the medial globus pallidus, substantia nigra pars reticulata and subthalamic nucleus. The PPN sends profuse ascending cholinergic efferent fibers to almost all the thalamic nuclei, to mediate phasic events in rapid-eye-movement sleep. Experimental evidence suggests that the PPN, along with other brain stem nuclei, is also involved in anti-nociception and startle reactions. In idiopathic Parkinson's disease (IPD) and parkinson plus syndrome, overactive pallidal and nigral inhibitory inputs to the PPN may cause sequential occurrences of PPN hypofunction, decreased excitatory PPN input to the substantia nigra, and aggravation of striatal dopamine deficiency. In addition, neuronal loss in the PPN itself may cause dopamine-r esistant parkinsonian deficits, including gait disorders, postural instability and sleep disturbances. In patients with IPD, such deficits may improve after posteroventral pallidotomy, but not after thalamotomy. One of the possible explanations for such differences is that dopamine-resistant parkinsonian deficits are mediated to the PPN by the descending pallido-PPN inhibitory fibers, which leave the pallido-thalamic pathways before they reach the thalamic targets.

Effects of Smoking on Patients with Parkinson's Disease

BACKGROUND: The cause of idiopathic Parkinson's disease (IPD) is unknown. Recent studies suggest that IPD occurs less frequently in smokers than in non-smokers, but remains a controversial topic. We performed a case-control study to investigate the relationship between IPD and smoking in Korea. METHODS:The smoking histories of 624 IPD patients were compared with 622 age- and sex-matched control subjects at the Asan Medical Center. Detailed informa-tion on smoking behavior was identified from a questionnaire and self report. A conditional logistic regression was used to calculate the odds ratio (OR) and control for potential confounds. RESULTS: With "never-smokers" as the refer-ence category, there was an inverse association between past-smokers and IPD (OR 0.617, p=0.029), and a stronger inverse association of IPD with current-smokers (OR 0.389, p<0.001). When smokers were stratified by the interval "since quitting", there was an inverse association between those who stopped smoking more than 10 years ago and IPD (OR 0.753, p=0.31), and a greater inverse relationship with those who stopped smoking 1 to 10 years (OR 0.489, p=0.017). A significant trend of decreased risk of IPD with pack-years of smoking was detected. CONCLUSIONS: This study suggests that IPD occurs less often in smokers than in non-smokers. The inverse dose-response relationship between smoking and IPD provides indirect evidence that smoking is biologically protective.

Neuronal Laterality & Postoperative Changes of GABA+Glu. Activity by In Vivo 1H MRS

Object of this study was to to evaluate the laterality of local cerebral cellular metabolism in various locations of the brain related to the symptomatic side of patients with clinically diagnosed idiopathic Parkinson's disease (IPD) and to verify GABA-related pathophysiology in IPD by comparing postoperative changes in (GABA+Glutamate)/Cr ratio from patients with IPD after stereotactic pallidotomy and thalamotomy. Fourteen patients with IPD(10 males and 4 females: age range 39-67 years) participated in the study. The patients were classified into two disease subgroups, one for tremor dominant group(n=7, T group), and the other bradykinesia and rigidity dominant one(n=7, B&R group). For T group, stereotactic VL(Vop, Vim) thalamotomy and subthalamotomy was performed and for the B&R group, stereotactic posteroventrolateral pallidotomy was selected. In Vivo 1H MRS study was performed on a 1.5 T MRI/MRS system(GE Sigma Advantage, version 4.8) using STEAM sequence after water suppression with CHESS RF pulse and dephasing gradients. After peak areas of creatine/phosphocreatine(Cr), choline-containning compound(Cho), N-Acetyl Aspartate(NAA), r-aminobutyric acid, (GABA) and glutamate(Glu) were calculated and processed, the metabolic ratios of NAA/Cr, Cho/Cr, and (GABA+Glu)/Cr in three different locations were calculated and compared with clinical symptoms and its changes after surgery. For the neuronal laterality in patients with IPD, there was significant differences of NAA/Cr ratio between the right and left sides of substantia nigra, thalamus and pallidum(p=0.00170). The magnitude of difference in NAA/Cr ratios between right and left side were significantly larger in substantia nigra(p=0.0141). Compared to the normal control values(1.82+/-0.52 in ages 27-50, 1.71+/-0.54 in ages 51-70 years), the neuronal loss was generally observed in at least one of three locationsin all patients. Moreover, NAA/Cr ratio was substantially lower in ipsilateral than contralateral substantia nigra of the parkinsonian symptomatic side. For preoperative(GABA+Glu)/Cr ratios of thalamus contralateral to the symptomatic side compared to that of ipsilateral, it was significant larger in thalamus of B&R group and significant smaller in T group. In the pallidotomy group, there was significant increase in the operated pallidum, whereas significant decrease in (GABA+Glu)/Cr ratios were noted in the operated side thalamus. And in the thalamotomy group, there were significant increase in the operated thalamus, whereas in the operated side pallidum, significant decrease in (GABA+Glu)/Cr ratios were noted. Neuronal laterality, pallidal neuronal loss and postoperative changes in GABA activity in patients with IPD were demonstrated on the basis of NAA/Cr and (GABA+Glu)/Cr ratio by In Vivo 1H MRS. The neuronal laterality was detected in the substantia nigra of all the parkinsonian patient, and NAA/Cr ratios in unilateral and bilateral disease were consistently lower in ipsilateral than in contralateral substantia nigra of the Parkinsonian disease side. Our result suggests that there may be another ongoing pathological process of ipsilateral neuronal degeneration with contralateral dopaminergic neuronal loss. The result of neuronal loss in pallidum supports with the previous reports concerning striatal degeneration in IPD. Our results concerning postoperative changes of (GABA+Glu)/Cr ratio suggests that separate pathophysiologic mechanisms may be involved in the development of two dominant symptom groups of IPD. That is, for the B&R group, pallidal overinhibition to the thalamus by the GABA-ergic system as previously noted, but for T group, a process other than GABA inhibitory mechanism with or without it may be involved.

Single oral levodopa challenge test in de novo patients with idiopathic Parkinson's disease and multiple system atrophy

BACKGROUND: In the previous literature, single oral levodopa challenge test has been reported as one of the methods differentiating multiple system atrophy (MSA) from idiopathic Parkinson's disease (IPD). However many of the patients included in these studies had been on levodopa treatment for a variable period when they were examined. We performed this study to determine the value of single oral levodopa challenge test in differential diagnosis between IPD and MSA. METHODS: After a single oral dose of SinemetR(25/250), we assessed the improvement of motor function in 54 de novo patients with parkinsonian symptoms (33 with IPD and 21 with probable MSA). We measured the time taken to finish 20 taps with unilateral hand on two marks separated 20 cm apart and to walk 10 meter from a sitting position and return. Such performances were assessed 5 times before the medication, every 15 min for first 2 hrs after the medication, and then every 30 min for the next 4 hrs. RESULTS: The mean of the age, mean of the duration of disease and mean of the Hoehn and Yahr scale score were not significantly different between the patients with IPD and those with MSA. The mean of the unified Parkinson's disease rating scale score between the patients with IPD and MSA was not significantly different. Baseline scores of the hand and the walking performance were not significantly different. The median of the time interval between the levodopa intake and maximum beneficial effects, mean of the objective improvement at the peak, and mean of the amount of maximum subjective improvement comparing to the baseline was not significantly different between the patients with IPD and MSA. Also there were no significant differences in all measurements between the patients with striatonigral and olivopontocerebellar type of MSA. CONCLUSIONS: These findings suggest that single oral levodopa challenge test is not so helpful for the differential diagnosis between de novo patients with IPD and MSA.