Yeong-In Kim

Poststroke Restless Legs Syndrome and Lesion location : Anatomical Considerations

Several case studies have reported on restless legs syndrome (RLS) associated with stroke. In this study, we investigated the prevalence and the lesion topography of poststroke RLS. There were 137 patients with ischemic stroke included in this study. The diagnosis of RLS was made 1 month after the index stroke using the criteria established by the International RLS Study Group. All patients enrolled underwent magnetic resonance imaging within 7 days of the onset of the stroke. The prevalence of stroke‐related RLS was calculated, and the topography of the associated ischemic lesions was analyzed. Among 137 patients, 17 patients (12.4%) were diagnosed with RLS after a stroke. Stroke‐related RLS was found in 10 out of 33 patients with a basal ganglia/corona radiata infarct (30.3%), 1 out of 8 patients with an internal capsular infarct (12.5%), and 1 out of 7 patients with a thalamic infarct (14.3%). In addition, one out of 54 with a cortical lesion with/without subcortical involvement (1.9%), and 4 out of 18 patients with a pontine lesion (22.2%) had RLS. The analysis of the lesions in the cortical and subcortical group showed only 1 patient in the cortical group had stroke‐related RLS, whereas 16 in the subcortical group had stroke‐related RLS. The results of this study suggest that lesions of the subcortical brain areas such as the pyramidal tract and the basal ganglia‐brainstem axis, which are involved in motor functions and sleep‐wake cycles, may lead to RLS symptoms in patients after an ischemic stroke.

Association of cognitive dysfunction with neurocirculatory abnormalities in early Parkinson disease

Objective: Cognitive impairment and neurocirculatory abnormalities such as orthostatic hypotension (OH), supine hypertension (SH), and failure to decrease blood pressure at night (nondipping) occur relatively commonly in Parkinson disease (PD); however, whether cognitive dysfunction in early PD is related to neurocirculatory abnormalities has not been established. Cognitive dysfunction in PD is associated with white matter hyperintensities on MRI. We report results of an analysis of neuropsychological and hemodynamic parameters in patients with early PD. Methods: Among 87 patients, 25 had normal cognition, 48 had mild cognitive impairment, and 14 had dementia, based on comprehensive neuropsychological tests. Orthostatic vital signs and ambulatory 24-hour blood pressure monitoring were recorded, and brain magnetic resonance scans were obtained for all patients. Results: Cognitive impairment was associated with OH, SH, and white matter hyperintensities but not with nondipping. Dementia and white matter hyperintensities were common in SH. Of 13 patients with OH + SH, every one had mild cognitive impairment or dementia. Conclusions: Cognitive dysfunction is related to neurocirculatory abnormalities, especially OH + SH, in early PD, raising the possibility that early detection and effective treatment of those abnormalities might slow the rate of cognitive decline.

Influence of white matter hyperintensities on the cognition of patients with Parkinson disease.

BackgroundWhite matter hyperintensities (WMH) have been associated with cognitive impairment in elderly persons and in patients with Alzheimer disease. However, the role of WMH in Parkinson disease (PD) dementia remains to be elucidated. MethodsThe cohort for this study comprised 71 consecutive patients with PD, all of whom completed a clinical assessment, neuropsychologic investigation, and magnetic resonance imaging of brain. WMH were rated using the semiquantitative visual rating system proposed by Scheltens et al. ResultsThe PD dementia group had significantly more WMH than the PD without dementia group in the evaluated brain regions except for the infratentorial area. The WMH showed a significant correlation with age, Unified Parkinsons Disease Rating Scale, Mini-Mental State Examination, sum of the box of Clinical Dementia Rating, and many of the cognitive domains. The linear regression model showed that the WMH was independently associated with cognitive impairment in patients with PD, regardless of age, sex, duration or severity of PD symptoms, and vascular risk factors. ConclusionsThese findings confirm that WMH might be associated with cognitive decline in patients with PD, regardless of age, sex, education status, duration or severity of PD symptoms, and vascular risk factors. This result suggests that other nonvascular factors contribute to the progression of dementia in patients with PD.

The prevalence and patterns of pharyngoesophageal dysmotility in patients with early stage Parkinson's disease†

Dysphagia occurs in the majority of patients with Parkinsons disease (PD) and is known to correlate with abnormalities of oropharyngeal function. The aim of this study was to evaluate pharyngoesophageal activity in patients with early‐stage PD. Newly diagnosed PD patients with a symptom duration not exceeding 3 years were included. All PD patients were questioned about symptoms of dysphagia and underwent combined multichannel intraluminal impedance manometry and multiple rapid swallow tests. Fifty‐four patients (22 men and 32 women, 67.1 ± 10.3 years) were enrolled. The duration of Parkinsonian motor symptoms was 11.5 ± 8.8 months, the Hoehn and Yahr stage was 1.6 ± 0.4, and the total Unified Parkinsons Disease Rating Scale was 25.1 ± 18.6. Esophageal manometry in the liquid swallow and viscous swallow tests was abnormal in 22 (40.7%) and 31 (67.4%) patients, respectively. Although manometric abnormalities were more common in patients with more severe dysphagia symptoms, many patients with no or minimal symptoms also had manometric abnormalities. Repetitive deglutition significantly correlated with failed peristalsis and incomplete bolus transit. Abnormal responses to multiple rapid swallow tests were found in 33 out of 54 patients; 29 with incomplete inhibition (repetitive contraction) and 4 with failed peristalsis. These results suggest that the majority of patients with early‐stage PD showed pharyngeal and esophageal dysfunction even before clinical manifestations of dysphagia, which may reflect selective involvement of either the brain stem or the esophageal myenteric plexus in early‐stage PD.

A randomized crossover comparative study of aspirin, cilostazol and clopidogrel in normal controls: analysis with quantitative bleeding time and platelet aggregation test

The effects of three antiplatelet drugs, aspirin, clopidogrel and cilostazol, were examined and compared using a quantitative bleeding time (QBT) test apparatus. In 12 healthy adult male subjects, a QBT test and platelet aggregation test were performed before and after medication. Cilostazol was found to be as effective as aspirin and clopidogrel in inhibiting platelet aggregation. Following the oral administration of aspirin and clopidogrel for 7 days, the bleeding time was significantly prolonged. In contrast, none of these QBT parameters were altered by the cilostazol treatment. This suggests that cilostazol has potent efficacy in inhibiting platelet aggregation without prolonging the bleeding time and changing the bleeding pattern.

Relationship between High-Sensitivity C-Reactive Protein and Clinical Functional Outcome after Acute Ischemic Stroke in a Korean Population

Background: High-sensitivity C-reactive protein (hs-CRP) has been shown to be a powerful predictor of coronary ischemic events. However, the prognosis of functional disability in patients with cerebrovascular disease has not been well established. Therefore, we performed this study to determine the prognostic significance of hs-CRP levels in patients with functional disability after acute ischemic stroke. Methods: A total of 417 Korean patients with ischemic stroke were examined within 24 h after symptom onset. hs-CRP measurements were obtained on admission and on the seventhhospital day. The correlations between the concentration of hs-CRP and functional disability duration 12 months after stroke onset were analyzed. Results: The present study showed that hs-CRP levels on admission and on the seventh hospital day were significantly correlated with the modified Rankin Scale (mRS) score 12 months after stroke onset. These results also demonstrated that mRS scores are more closely associated with hs-CRP levels on the seventh hospital day than hs-CRP levels on admission. Conclusion: This study demonstrated that elevated hs-CRP levels on the seventh hospital day, rather than within 24 h after stroke onset, could strongly predict the prognosis of functional disability. These results supported that hs-CRP is a useful marker of ischemic stroke in the Korean population.

The severity of leukoaraiosis correlates with the clinical phenotype of Parkinson’s disease

The impact of leukoaraiosis on Parkinsons disease (PD) has not been completely explained. We evaluated 141 patients with PD to assess the role of leukoaraiosis and determined its influence on the clinical phenotype of PD. Clinical assessments during off medication and leukoaraiosis grading were performed according to the atherosclerosis risk in communities (ARIC) study. Patients were grouped into two phenotypes, tremor or postural instability and gait difficulty (PIGD)-dominant groups. Associations between the age at onset, gender, disease duration, cardiovascular risk factors, leukoaraiosis grade and the disease phenotype were analyzed. In addition, the role of the leukoaraiosis grade in relationship to the parkinsonian motor handicaps was evaluated. The leukoaraiosis correlated with the severity of the clinical symptoms of PD as measured by the United Parkinsons disease rating scale (UPDRS) scores and the Hoehn and Yahr (H + Y) stage. There were significant correlations observed between the leukoaraiosis grade and specific motor handicaps especially those with axial symptoms. Multivariate logistic regression analysis showed that the leukoaraiosis grade was independently associated with the PIGD motor phenotype of PD. The leukoaraiosis grade was independently associated with the PIGD motor phenotype of PD; this might be explained by the affects on nondopaminergic subcortical pathways. These results have implications for clinical management of PD with regard to the control of vascular risk factors.

Clinical Significance of Silent Cerebral Infarctions in Patients With Alzheimer Disease

BackgroundAlthough recent advances in the epidemiology of Alzheimer disease (AD) suggest a strong association between vascular factors predisposing to cerebrovascular disease and AD, the results of many studies on the relation between cerebrovascular disease and AD have been yet controversial. Therefore, we conducted this study to clarify the relation between concomitant silent cerebral infarctions and the cognitive decline of AD patients. MethodsOne hundred and fifty subjects participated in this study: 51 patients had AD, 44 patients had AD with silent cerebral infarction (ADI), and there were 45 control subjects. These subjects received the global cognitive function testing and they were all evaluated with detailed neuropsychologic tests including attention, memory, language, and also the visuospatial and frontal function. ResultsCompared with the control group, the patients with AD and ADI demonstrated significantly impairments in all cognitive domains. The ADI group showed more marked impairment than did the AD group on the domains including the language function, the delayed recall test, and semantic fluency. ConclusionsADI showed more severe cognitive decline than AD, indicating that cerebrovascular disease contributes to the severity of cognitive decline. These results suggest that prevention of cerebrovascular disease can play an important role in preventing the rapid cognitive decline of AD.

1α,25-Dihydroxyvitamin D3 Protects Dopaminergic Neurons in Rodent Models of Parkinson's Disease through Inhibition of Microglial Activation

Background Recent studies have demonstrated the molecular basis of the immunomodulatory and anti-inflammatory activities of 1,25-dihydroxyvitamin D3(1,25-(OH)2D3). This hormone improves behavioral deficits and normalizes the nigral dopamine levels in animal models of Parkinsons disease (PD). Methods We studied whether the administration of 1,25-(OH)2D3 would protect against 6-hydroxydopa (6-OHDA)- and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced neuronal injury, and its potential regulatory effect on microglia activation. Results We found that 1,25-(OH)2D3 pretreatment significantly decreased 6-OHDA- and MPTP-induced dopaminergic neuronal loss in the substantia nigra pars compacta by preventing the activation of microglia. This observed neuroprotective effect in MPTP-treated mice that were given 1,25-(OH)2D3 may be attributable to inhibition of proinflammatory cytokine expression. Conclusion These results suggest that 1,25-(OH)2D3 is a potentially valuable neuroprotective agent; it may therefore be considered for the treatment of pathologic conditions of the central nervous system, such as PD, where inflammation-induced neurodegeneration occurs.

Cognitive Impairment in Essential Tremor without Dementia

Background and purpose Several clinical studies have demonstrated that patients with essential tremor (ET) may have cognitive deficits; however, there are no published data regarding detailed neuropsychological assessments of ET without dementia. We therefore conducted a case-control study of cognitive function in patients with ET. Methods The cohort for this study comprised 34 consecutive patients with ET without dementia and 33 age-matched controls, all of who completed a dementia-screening questionnaire and underwent a detailed neuropsychological investigation. Results Severe impairments were observed in most domains for the ET group compared to the controls, including attention, part of language function, verbal memory, and frontal executive functions. Conclusions Our results support the finding that the subclinical cognitive deficits characterized by attention, verbal memory impairments, and executive dysfunction are a clinical feature of ET. In addition, our results also support the finding that age at examination and educational status are the most important risk factors associated with cognitive deficits in patients with ET.