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Dive into the research topics where Bichun Ouyang is active.

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Featured researches published by Bichun Ouyang.


Neurology | 2005

Hallucinations and sleep disorders in PD Ten-year prospective longitudinal study

Christopher G. Goetz; Bichun Ouyang; Alice Negron; Glenn T. Stebbins

Objective: To assess prospectively progression and relationship of hallucinations and sleep disorders over a 10-year longitudinal study of patients with Parkinson disease (PD). Methods: Eighty-nine patients with PD were recruited to fill cells of normal sleep without hallucinations (n = 20), sleep fragmentation only (n = 20), vivid dreams/nightmares (n = 20), hallucinations with insight (n = 20), and hallucinations without insight (n = 9). At baseline, 0.5, 1.5, 4, 6, and 10 years, sleep disorders and hallucinations were assessed by standardized scales with the longitudinal data analyzed by generalized estimating equations with assumptions of linearity in time. Results: At 10 years, we could account for all subjects (27 interviewed, 61 deceased, and 1 too ill for interview). Hallucination prevalence and severity increased over time (p < 0.0001, p = 0.0001). Acting out dreams also increased over time (p = 0.001). In contrast, presence of vivid dreams/nightmares or sleep fragmentation did not increase over time. For all visits, the prevalence of sleep fragmentation did not differ between subjects with vs without hallucinations (odds ratio [OR] = 1.50, p = 0.09). However, severe sleep fragmentation was associated with concurrent hallucinations (OR 2.01, p = 0.006). The presence of hallucinations was also highly associated with concurrent vivid dreams/nightmares (OR = 2.60, p < 0.0001) and with concurrent acting out dreams (OR = 2.38, p = 0.0004). Among the baseline nonhallucinators, no sleep abnormalities at study entry predicted future development of hallucinations. Conclusions: Hallucinations and sleep abnormalities follow very different patterns of progression in PD over 10 years. Whereas patients with hallucinations often have concurrent sleep aberrations, no sleep problem is predictive of future hallucinations.


The American Journal of Clinical Nutrition | 2010

Longitudinal association of vitamin B-6, folate, and vitamin B-12 with depressive symptoms among older adults over time

Kimberly A. Skarupski; Christine C. Tangney; Hong Li; Bichun Ouyang; Denis A. Evans; Martha Clare Morris

BACKGROUND B-vitamin deficiencies have been associated with depression; however, there is very little prospective evidence from population-based studies of older adults. OBJECTIVE We examined whether dietary intakes of vitamins B-6, folate, or vitamin B-12 were predictive of depressive symptoms over an average of 7.2 y in a community-based population of older adults. DESIGN The study sample consisted of 3503 adults from the Chicago Health and Aging project, an ongoing, population-based, biracial (59% African American) study in adults aged > or =65 y. Dietary assessment was made by food-frequency questionnaire. Incident depression was measured by the presence of > or =4 depressive symptoms from the 10-item version of the Center for Epidemiologic Studies Depression scale. RESULTS The logistic regression models, which used generalized estimating equations, showed that higher total intakes, which included supplementation, of vitamins B-6 and B-12 were associated with a decreased likelihood of incident depression for up to 12 y of follow-up, after adjustment for age, sex, race, education, income, and antidepressant medication use. For example, each 10 additional milligrams of vitamin B-6 and 10 additional micrograms of vitamin B-12 were associated with 2% lower odds of depressive symptoms per year. There was no association between depressive symptoms and food intakes of these vitamins or folate. These associations remained after adjustment for smoking, alcohol use, widowhood, caregiving status, cognitive function, physical disability, and medical conditions. CONCLUSION Our results support the hypotheses that high total intakes of vitamins B-6 and B-12 are protective of depressive symptoms over time in community-residing older adults.


Stroke | 2010

Acute Brain Infarcts After Spontaneous Intracerebral Hemorrhage A Diffusion-Weighted Imaging Study

Shyam Prabhakaran; Rajesh Gupta; Bichun Ouyang; Sayona John; Richard E. Temes; Yousef Mohammad; Vivien H. Lee; Thomas P. Bleck

Background and Purpose— We aimed to determine the prevalence of acute brain infarcts using diffusion-weighted imaging (DWI) in patients with spontaneous intracerebral hemorrhage (ICH). Methods— We collected data on consecutive patients with spontaneous ICH admitted to our institution between August 1, 2006 and December 31, 2008 and in whom DWI was performed within 28 days of admission. Patients with hemorrhage attributable to trauma, tumor, aneurysm, vascular malformation, and hemorrhagic conversion of arterial or venous infarction were excluded. Restricted diffusion within, contiguous with, or immediately neighboring the hematoma or chronic infarcts was not considered abnormal. Using multivariable logistic regression, we evaluated potential predictors of DWI abnormality including clinical and radiographic characteristics and treatments. A probability value <0.05 was considered significant in the final model. Results— Among 118 spontaneous ICH patients (mean 59.6 years, 47.5% male, and 31.4% white) who also underwent MRI, DWI abnormality was observed in 22.9%. The majority of infarcts were small (median volume 0.25 mL), subcortical (70.4%), and subclinical (88.9%). Factors independently associated with DWI abnormality were prior ischemic stroke (P=0.002), MAP lowering by ≥40% (P=0.004), and craniotomy for ICH evacuation (P=0.001). Conclusion— We found that acute brain infarction is relatively common after acute spontaneous ICH. Several factors, including aggressive blood pressure lowering, may be associated with acute ischemic infarcts after ICH. These preliminary findings require further prospective study.


Movement Disorders | 2013

Defining optimal cutoff scores for cognitive impairment using Movement Disorder Society Task Force criteria for mild cognitive impairment in Parkinson's disease

Jennifer G. Goldman; Samantha Holden; Bryan Bernard; Bichun Ouyang; Christopher G. Goetz; Glenn T. Stebbins

The recently proposed Movement Disorder Society (MDS) Task Force diagnostic criteria for mild cognitive impairment in Parkinsons disease (PD‐MCI) represent a first step toward a uniform definition of PD‐MCI across multiple clinical and research settings. However, several questions regarding specific criteria remain unanswered, including optimal cutoff scores by which to define impairment on neuropsychological tests. Seventy‐six non‐demented PD patients underwent comprehensive neuropsychological assessment and were classified as PD‐MCI or PD with normal cognition (PD‐NC). The concordance of PD‐MCI diagnosis by MDS Task Force Level II criteria (comprehensive assessment), using a range of standard deviation (SD) cutoff scores, was compared with our consensus diagnosis of PD‐MCI or PD‐NC. Sensitivity, specificity, and positive and negative predictive values were examined for each cutoff score. PD‐MCI subtype classification and distribution of cognitive domains impaired were evaluated. Concordance for PD‐MCI diagnosis was greatest for defining impairment on neuropsychological tests using a 2 SD cutoff score below appropriate norms. This cutoff also provided the best discriminatory properties for separating PD‐MCI from PD‐NC compared with other cutoff scores. With the MDS PD‐MCI criteria, multiple domain impairment was more frequent than single domain impairment, with predominant executive function, memory, and visuospatial function deficits. Application of the MDS Task Force PD‐MCI Level II diagnostic criteria demonstrates good sensitivity and specificity at a 2 SD cutoff score. The predominance of multiple domain impairment in PD‐MCI with the Level II criteria suggests not only influences of testing abnormality requirements, but also the widespread nature of cognitive deficits within PD‐MCI.


Stroke | 2012

Intravenous Thrombolysis for Stroke Increases Over Time at Primary Stroke Centers

Shyam Prabhakaran; Maggie McNulty; Kathleen O'Neill; Bichun Ouyang

Background and Purpose— We evaluated the impact that duration as a primary stroke center (PSC) had on tissue-type plasminogen activator (tPA) utilization for acute ischemic stroke. Methods— A retrospective analysis of the Illinois Hospital Association CompData was performed identifying those patients with primary discharge diagnosis of acute ischemic stroke based on International Classification of Diseases version 9 codes. We assessed utilization of tPA by International Classification of Diseases version 9 procedure code (99.10). We categorized patients as cared for at non-PSC, PSC >1 year before, ⩽1 year before, ⩽1 year after, and >1 year after certification. We used generalized estimating equations to calculate adjusted odds ratios for tPA utilization by PSC category. Results— Among 119 539 acute ischemic stroke patients (mean age, 72 years; 55.2% women), tPA use was 1.9% but increased by PSC category (P<0.001): (1) non-PSC 0.9%; (2) >1 year before PSC certification 1.4%; (3) ⩽1 year before certification 3.2%; (4) ⩽1 year after certification 4.3%; and (5) >1 year after certification 6.5%. Adjusting for age, insurance status, admission source, year of study, region of Illinois, and hospital bed size, the odds of tPA utilization increased with advancing stage of PSC certification (highest category: adjusted odds ratio, 2.37; 95% confidence interval, 1.52–3.71). Conclusions— Although increasing over time, stroke thrombolysis is strongly impacted by the PSC certification process. Rather than waning or stagnating, tPA utilization increases at PSC from the earliest phases of preparation through certification and subsequent maintenance.


Neurology | 2011

Should TIA patients be hospitalized or referred to a same-day clinic? A decision analysis

Jay K. Joshi; Bichun Ouyang; Shyam Prabhakaran

Objective: For patients presenting with TIA, a previous study concluded that hospitalization is cost-effective compared to discharge without treatment from the emergency department. We performed a cost-effectiveness analysis of hospitalization vs urgent clinic evaluation following TIA. Methods: Among a cohort of TIA patients, we created a decision tree model to compare the decision to hospitalize or refer to urgent-access specialty clinic. We estimated probabilities, utilities, and direct costs from the available literature and calculated incremental cost-effectiveness ratio (ICER). We assumed equal access to standard medical treatments between the 2 approaches; however, we estimated higher tissue plasminogen activator (tPA) utilization among hospitalized patients. We performed sensitivity analyses to assess all assumptions in our model. Results: In patients with TIA aged 65–74 years, hospitalization yielded additional 0.00026 quality-adjusted life-years (QALYs) at 1 year, but at an additional cost of


Movement Disorders | 2015

Diagnosing PD-MCI by MDS Task Force criteria: how many and which neuropsychological tests?

Jennifer G. Goldman; Samantha Holden; Bichun Ouyang; Bryan Bernard; Christopher G. Goetz; Glenn T. Stebbins

5,573 per patient compared to urgent clinic evaluation (ICER =


Movement Disorders | 2011

Visual plus nonvisual hallucinations in Parkinson's disease: Development and evolution over 10 years†‡§

Christopher G. Goetz; Glenn T. Stebbins; Bichun Ouyang

21,434,615/QALY). Over 30 years, the ICER was


Movement Disorders | 2011

FMR1 gray-zone alleles: association with Parkinson's disease in women?

Deborah A. Hall; Elizabeth Berry-Kravis; Wenting Zhang; Flora Tassone; Elaine Spector; Gary O. Zerbe; Paul J. Hagerman; Bichun Ouyang; Maureen A. Leehey

3,473,125/QALY. These results were not sensitive to varying 48-hour stroke risk, length of stay, tPA utilization rate, QALYs saved per tPA treatment, and hospitalization and clinic costs, and cost saved per tPA treatment. Conclusion: Despite increased access to tPA in the hospital, we found that hospitalization is not cost-effective compared to same-day clinic evaluation following TIA. A very small fraction of patients benefits from hospitalization if urgent-access TIA clinics are available. The widespread development of urgent-access TIA clinics is warranted.


Journal of NeuroInterventional Surgery | 2012

The role of circle of Willis anomalies in cerebral aneurysm rupture.

Marc A. Lazzaro; Bichun Ouyang; Michael Chen

The optimal properties of a comprehensive (level II) neuropsychological battery for determining Parkinsons disease mild cognitive impairment (PD‐MCI) by Movement Disorder Society (MDS) Task Force criteria remain unresolved.

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Christopher G. Goetz

Rush University Medical Center

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Vivien H. Lee

Rush University Medical Center

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Bryan Bernard

Rush University Medical Center

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Glenn T. Stebbins

Rush University Medical Center

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James Conners

Rush University Medical Center

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Elizabeth Berry-Kravis

Rush University Medical Center

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Michael Chen

Rush University Medical Center

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