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JMD : Journal of Movement Disorders

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6 "Seok Jong Chung"
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Original Article
Accuracy of Machine Learning Using the Montreal Cognitive Assessment for the Diagnosis of Cognitive Impairment in Parkinson’s Disease
Junbeom Jeon, Kiyong Kim, Kyeongmin Baek, Seok Jong Chung, Jeehee Yoon, Yun Joong Kim
J Mov Disord. 2022;15(2):132-139.   Published online May 26, 2022
DOI: https://doi.org/10.14802/jmd.22012
  • 629 View
  • 67 Download
AbstractAbstract PDFSupplementary Material
Objective
The Montreal Cognitive Assessment (MoCA) is recommended for assessing general cognition in Parkinson’s disease (PD). Several cutoffs of MoCA scores for diagnosing PD with cognitive impairment (PD-CI) have been proposed, with varying sensitivity and specificity. This study investigated the utility of machine learning algorithms using MoCA cognitive domain scores for improving diagnostic performance for PD-CI.
Methods
In total, 2,069 MoCA results were obtained from 397 patients with PD enrolled in the Parkinson’s Progression Markers Initiative database with a diagnosis of cognitive status based on comprehensive neuropsychological assessments. Using the same number of MoCA results randomly sampled from patients with PD with normal cognition or PD-CI, discriminant validity was compared between machine learning (logistic regression, support vector machine, or random forest) with domain scores and a cutoff method.
Results
Based on cognitive status classification using a dataset that permitted sampling of MoCA results from the same individual (n = 221 per group), no difference was observed in accuracy between the cutoff value method (0.74 ± 0.03) and machine learning (0.78 ± 0.03). Using a more stringent dataset that excluded MoCA results (n = 101 per group) from the same patients, the accuracy of the cutoff method (0.66 ± 0.05), but not that of machine learning (0.74 ± 0.07), was significantly reduced. Inclusion of cognitive complaints as an additional variable improved the accuracy of classification using the machine learning method (0.87–0.89).
Conclusion
Machine learning analysis using MoCA domain scores is a valid method for screening cognitive impairment in PD.
Review Article
Emerging Concepts of Motor Reserve in Parkinson’s Disease
Seok Jong Chung, Jae Jung Lee, Phil Hyu Lee, Young H. Sohn
J Mov Disord. 2020;13(3):171-184.   Published online August 31, 2020
DOI: https://doi.org/10.14802/jmd.20029
  • 6,491 View
  • 257 Download
  • 10 Citations
AbstractAbstract PDF
The concept of cognitive reserve (CR) in Alzheimer’s disease (AD) explains the differences between individuals in their susceptibility to AD-related pathologies. An enhanced CR may lead to less cognitive deficits despite severe pathological lesions. Parkinson’s disease (PD) is also a common neurodegenerative disease and is mainly characterized by motor dysfunction related to striatal dopaminergic depletion. The degree of motor deficits in PD is closely correlated to the degree of dopamine depletion; however, significant individual variations still exist. Therefore, we hypothesized that the presence of motor reserve (MR) in PD explains the individual differences in motor deficits despite similar levels of striatal dopamine depletion. Since 2015, we have performed a series of studies investigating MR in de novo patients with PD using the data of initial clinical presentation and dopamine transporter PET scan. In this review, we summarized the results of these published studies. In particular, some premorbid experiences (i.e., physical activity and education) and modifiable factors (i.e., body mass index and white matter hyperintensity on brain image studies) could modulate an individual’s capacity to tolerate PD pathology, which can be maintained throughout disease progression.
Original Article
Association between Olfactory Deficit and Motor and Cognitive Function in Parkinson’s Disease
Han Soo Yoo, Seok Jong Chung, Yang Hyun Lee, Byoung Seok Ye, Young H. Sohn, Phil Hyu Lee
J Mov Disord. 2020;13(2):133-141.   Published online April 6, 2020
DOI: https://doi.org/10.14802/jmd.19082
  • 5,995 View
  • 235 Download
  • 11 Citations
AbstractAbstract PDFSupplementary Material
Objective
To investigate whether baseline olfactory dysfunction in Parkinson’s disease (PD) patients is associated with baseline and longitudinal motor and cognitive function.
Methods
We recruited 228 drug-naïve PD patients who were followed for a mean of 6 years. Patients underwent the Cross-Cultural Smell Identification Test (CCSIT), a neuropsychological test, and N-(3-[18F]fluoropropyl)-2β-carbomethoxy-3β-(4-iodophenyl) nortropane positron emission tomography within 6 months of the baseline evaluation. Olfactory dysfunction was categorized as normosmia (CCSIT score ≥ 9), hyposmia (CCSIT score 5–8), and anosmia (CCSIT score ≤ 4). During the follow-up period, we investigated changes in the levodopa-equivalent dose (LED) and the occurrence of wearing-off, levodopa-induced dyskinesia, and dementia.
Results
Among the PD patients, 80.7% were hyposmic at the time of diagnosis, and 26.1% were anosmic. Baseline olfactory dysfunction was not associated with either initial parkinsonian motor symptoms or with the longitudinal LED increment and motor complications. Meanwhile, the anosmic group had lower baseline scores on the Korea version of the Boston Naming Test and Stroop color reading test than the normosmic and hyposmic groups. The anosmic group exhibited a higher rate of conversion to dementia than the normosmic [adjusted hazard ratio (HR) 3.99, 95% confidence interval (CI) 1.08–14.72] and hyposmic (adjusted HR 2.48, 95% CI 1.15–5.32) PD groups, regardless of baseline motor deficits and cognitive status.
Conclusion
Baseline olfactory dysfunction was not associated with motor deficits and complications, but it was associated with cognitive dysfunction and prognosis, suggesting that severe olfactory impairment may reflect early cortical involvement, probably in the frontotemporal region, and rapid spreading of Lewy body pathology.
Case Report
A Case of Abnormal Postures in the Left Extremities after Pontine Hemorrhage: Dystonia or Pseudodystonia?
Chan Wook Park, Seok Jong Chung, Young H. Sohn, Phil Hyu Lee
J Mov Disord. 2020;13(1):62-65.   Published online January 31, 2020
DOI: https://doi.org/10.14802/jmd.19074
  • 3,382 View
  • 116 Download
  • 1 Citations
AbstractAbstract PDFSupplementary Material
It is difficult to determine the pathoanatomical correlates of dystonia because of its complex pathophysiology, and most cases with secondary dystonia are associated with basal ganglia lesions. Moreover, it is a challenging issue that patients with abnormal postures accompanied by other neurological findings in the affected body part (e.g., sensory loss) can be diagnosed with true dystonia or pseudodystonia. Here, we report a case of abnormal postures with loss of proprioception in the left extremities after right dorsal pontine hemorrhage.
Original Article
Heterogeneous Patterns of Striatal Dopamine Loss in Patients with Young- versus Old-Onset Parkinson’s Disease: Impact on Clinical Features
Seok Jong Chung, Han Soo Yoo, Yang Hyun Lee, Phil Hyu Lee, Young H. Sohn
J Mov Disord. 2019;12(2):113-119.   Published online May 30, 2019
DOI: https://doi.org/10.14802/jmd.18064
  • 5,147 View
  • 128 Download
  • 14 Citations
AbstractAbstract PDFSupplementary Material
Objective
Ample evidence has suggested that age at onset of Parkinson’s disease (PD) is associated with heterogeneous clinical features in individuals. We hypothesized that this may be attributed to different patterns of nigrostriatal dopamine loss.
Methods
A total of 205 consecutive patients with de novo PD who underwent 18F-FP-CIT PET scans (mean follow-up duration, 6.31 years) were divided into three tertile groups according to their age at onset of parkinsonian motor symptoms. Striatal dopamine transporter (DAT) availability was compared between the old- (n = 73) and young-onset (n = 66) groups. In addition, the risk of developing freezing of gait (FOG) and longitudinal requirements for dopaminergic medications were examined.
Results
The old-onset PD group (mean age at onset, 72.66 years) exhibited more severe parkinsonian motor signs than the young-onset group (52.58 years), despite comparable DAT availability in the posterior putamen; moreover, the old-onset group exhibited more severely decreased DAT availability in the caudate than the young-onset group. A Cox regression model revealed that the old-onset PD group had a higher risk for developing FOG than the young-onset group [hazard ratio 2.523, 95% confidence interval (1.239–5.140)]. The old-onset group required higher doses of dopaminergic medications for symptom control than the young-onset group over time.
Conclusion
The present study demonstrated that the old-onset PD group exhibited more severe dopamine loss in the caudate and were more likely to develop gait freezing, suggesting that age at onset may be one of the major determinants of the pattern of striatal dopamine depletion and progression of gait disturbance in PD.
Case Report
A Case of Isolated Middle Cerebral Artery Stenosis with Hemichorea and Moyamoya Pattern Collateralization
Seok Jong Chung, Hyung Seok Lee, Han Soo Yoo, Kyung Min Kim, Ki Jeong Lee, Jong-Soo Kim, Jae-Wook Lee, Jong Hun Kim, Jeong Hee Cho, Gyu Sik Kim, Jun Hong Lee, Sun-Ah Choi
J Mov Disord. 2013;6(1):13-16.
DOI: https://doi.org/10.14802/jmd.13003
  • 9,862 View
  • 90 Download
  • 3 Citations
AbstractAbstract PDF

Isolated middle cerebral artery (MCA) stenosis in young patients with no other medical condition may be a unique pathologic entity with a benign long-term course. Generally, moyamoya disease shows a progression of stenosis from internal cerebral artery (ICA) to other intracranial vessel. A 26-year-old woman was admitted for choreic movements of the right arm and leg. Brain magnetic resonance imaging showed no stroke. Conventional angiography revealed 48% stenosis of the left M1 without ICA stenosis. Single photon emission computed tomography revealed perfusion asymmetry after acetazolamide injection, suggesting decreased uptake in the left basal ganglia and the cerebral cortex. Her hemichorea was mildly decreased with risperidone. One year later, follow-up angiography showed complete occlusion of the left M1 with neovascularization suggestive of moyamoya disease. The patient underwent bypass surgery and her hemichorea disappeared. This may be an atypical presentation of moyamoya disease. The bypass surgery was an effective measure for restoring the vascular insufficiency and, resultantly, controlling her hemichorea.


JMD : Journal of Movement Disorders