Rong-Chi Chen

Environmental risk factors and Parkinson's disease A case‐control study in Taiwan

To explore environmental risk factors for Parkinsons disease (PD) in Taiwan, we investigated 120 patients with PD and 240 hospital control subjects matched with patients on age (± 2 years) and sex. Based on a structured open-ended questionnaire, we carried out standardized interviews to obtain history of exposure to environmental factors, including place of residence, source of drinking water, and environmental and occupational exposures to various agricultural chemicals. In the univariate analysis, the history of living in a rural environment, farming, use of herbicides/pesticides, and use of paraquat were associated with an increased PD risk in a dose-response relationship. After adjustment for multiple risk factors through conditional logistic regression, the biological gradient between PD and previous uses of herbicidesipesticides and paraquat remained significant. The PD risk was greater among subjects who had used paraquat and other herbicide/pesticides than those who had used herbicides/pesticides other than paraquat. There were no significant differences in occupational exposures to chemicals, heavy metals, and minerals between PD patients and matched control subjects. The duration of drinking well water and alcohol consumption was not significantly associated with PD. There was an inverse relationship between cigarette smoking and PD. Environmental factors, especially exposures to paraquat and herbicides/pesticides, may play important roles in the development of PD in Taiwan.

Subtypes of Ischemic Stroke: A Hospital-Based Stroke Registry in Taiwan (SCAN-IV)

BACKGROUND AND PURPOSE To better understand the clinical pattern and further elucidate the risk factors and outcome in different subtypes of cerebral infarction (CI) of the Chinese in Taiwan, we analyzed the National Taiwan University Hospital Stroke Registry in 1995 and performed an ethnic comparison with similar data banks. METHODS From the National Taiwan University Hospital Stroke Registry in 1995, 676 patients (383 men and 293 women; mean age, 64.9 years; SD, 13.8 years; range, 1 to 98 years) with CI were recruited for this analysis. CI was classified into five subtypes based on clinical manifestations, ultrasonographic studies, and neuroimaging findings: large-artery atherosclerosis, lacunae, cardioembolism, other less common determined causes, and undetermined cause. Vascular risk factors, extracranial carotid artery atherosclerosis, and 30-day case-fatality rates were investigated in each subtype of CI. RESULTS Of all CI patients, 17%, 29%, 20%, 6%, and 29% were classified as large-artery atherosclerosis, lacunae, cardioembolism, other determined causes, and undetermined cause subtypes, respectively. The present results were compared with those from eight similar Western stroke registries. The relative incidence of lacunar CI in Chinese patients was more common, but large-artery atherosclerotic CI was less common than in whites. Hypertension was frequently seen in CI patients, especially in those with lacunae (85%) and large-artery atherosclerosis (69%). Patients with cardioembolism had a higher percentage of atrial fibrillation (69%), left ventricular hypertrophy, and ischemic heart disease than the other patients. Patients with large-artery atherosclerosis had more vascular risk factors, such as hypertension, diabetes mellitus, smoking, and carotid stenosis. Cardioembolic patients had higher case-fatality rates than other CI patients. Of the cardioembolic patients, 17.3% and 21.8% died within 30 days and during hospitalization, respectively. CONCLUSIONS The proportion of CI subtypes varied in different stroke registries. This may be partly due to applied classification criteria and racial-ethnic differences. Awareness of the risk factors and outcome in each subtype of stroke may afford further insights into the surveillance and treatment of cerebrovascular disease.

Carotid atherosclerosis, intima media thickness and risk factors—an analysis of 1781 asymptomatic subjects in Taiwan

The aim of this study was to investigate the association of intima media thickness (IMT) and plaque with risk factors for atherosclerosis in asymptomatic subjects in Taiwan. Between 1998 and 2001, the study recruited 1781 asymptomatic subjects (1131 men and 650 women [mean age, 49 years; range 18-85 years]). These were examined by B-mode ultrasound to measure the IMT at the far wall of the common carotid artery (CCA) and the extent of plaque formation. A wide range of vascular risk factors including age, gender, smoking, body mass index, blood chemistry, and previous history were surveyed. The mean (+/-S.D.) IMT observed was 0.68 (+/-0.12) and 0.66 (+/-0.11) mm for men and women, respectively, (P=0.0008). The mean (S.D.) IMT of the CCA was 0.66 (+/-0.12) mm on the right side and 0.68 (+/-0.12) mm on the left side (P=0.0004). IMT increased with aging, according to the equation IMT=(0.005xage in years)+0.403 [corrected]. Higher IMT was associated with male gender, and IMT was greater in the left CCA. About 36.9% of subjects had carotid plaques. The percentage of plaque increased with aging. The plaque prevalence was positively associated with IMT. The value of IMT over the cut point of 0.68 mm correlated with obviously increased risk of carotid atherosclerosis. Age, systolic blood pressure and fasting blood sugar were independent risk factors related to both carotid atherosclerosis and thick IMT.

Prevalence, incidence, and mortality of PD: A door-to-door survey in Ilan County, Taiwan

Background: The reported prevalence and incidence rates of PD were significantly lower in China than those in Western countries. People in China and Taiwan have a similar ethnic background. Objective: To investigate the prevalence, incidence, and mortality rate of PD in Taiwan. Method: The authors conducted a population-based survey using a two-stage door-to-door approach for patients aged 40 years or older in Ilan, Taiwan. Patients were diagnosed with PD by having at least two of the four cardinal signs of parkinsonism and exclusion of seconddary parkinsonism. To identify new cases of PD after the survey, patients with negative results of parkinsonism in the first stage were matched to the information on clinical diagnosis of PD from the Bureau of National Health Insurance toward the end of December 31, 1997. All cases of PD were linked to the Taiwan mortality registration to ascertain causes of deaths until December 31, 1999. Results: The participation rate was 88.1% among the 11,411 contacted individuals. Thirty-seven cases of PD were identified. The age-adjusted prevalence rate of PD for all age groups was 130.1 per 100,000 population after being adjusted to the 1970 US census, assuming no cases of PD would be found among those younger than 40 years of age. Of 9972 non-PD subjects in the first screen, 15 new cases of PD were ascertained. The age-adjusted incidence rate was 10.4 per 100,000 population for all age groups. The case fatality rate of PD after a 7-year follow-up was 40.4% (21 deaths in 52 patients with PD). The relative risk of death for PD cases versus non-PD cases was 3.38 (95% CI: 2.05–4.34). The 5-year cumulative survival rate in PD cases (78.85%) was statistically lower than that in non-PD cases (92.84%). Conclusion: The prevalence and incidence rates of PD in Taiwan were much higher than those reported in China, but closer to those in Western countries. These results suggest that environmental factors may be more important than racial factors in the pathogenesis of PD.

Anticardiolipin antisera from lupus patients with seizures reduce a GABA receptor-mediated chloride current in snail neurons

The effects of circulating anticardiolipin (ACL) antisera in lupus patients on the LP5 central neuron of snail were studied. Both GABA and glutamate increased a chloride conductance of the LP5 neuron. The ACL antisera decreased the GABA-elicited responses in a concentration dependent manner while it had no effect on glutamate-elicited responses. The ACL antisera affected neither the resting membrane current, nor the membrane conductivity of neuron. Antisera without the activity of anticardiolipin did not decrease the GABA-elicited responses. The seizure incidence of the patients with higher ACL antisera levels is also higher. It is concluded that ACL antisera inhibited the GABA ionophore receptor complex in a snail central neuron.

Health related quality of life in adult patients with epilepsy compared with a general reference population in Taiwan

To compare the health-related quality of life (HRQL) for patients with epilepsy and health subjects, we collected the clinical and demographic data and information on health states by using the Taiwan version of World Health Organization quality of life (WHOQOL)-BREF questionnaire in 296 patients (aged 19-73 years) with confirmed active epilepsy visiting the clinic of National Taiwan University Hospital, and 296 age-, gender-, municipal- and education-matched Taiwanese healthy subjects sampled from a national health interview survey. Multiple regression analyses with stepwise selection strategy were conducted to study risk factors for impairment of HRQL. Patients with epilepsy have poorer HRQL than the healthy population in physical, psychological and social domains but not in environment domain (p<0.005). Patients with less than 4 attacks during the previous 1 month had a better score in the availability and quality of health and social care in environment domain than healthy subjects (p<0.05). After controlling other determinants, seizure frequency, and comobid with other diseases are the important factors in predicting HRQL for epilepsy patients. Patients with employment and married had a significantly better HRQL. Effective control of seizure frequency and thoughtful promotion of positive attitudes in community are essential to improve the HRQL of epilepsy patients.

Review : Elevated levels of anticardiolipin antibodies and epilepsy in lupus patients

To examine the association between anticardiolipin (aCL) antibodies and epilepsy, we inves tigated the serum titers of aCL antibodies in a total 252 systemic lupus erythematosus (SLE) patients recruited in a prospective study. Twenty-one cases with epilepsy which were not attributable to any causes other than SLE were identified after being followed-up for five years. The clinical manifestations were recorded and blood samples were tested for the presence of aCL antibodies (IgG, IgM and IgA isotypes). Among 21 patients with epilepsy, 12 (57.1%), 2 (9.5%) and 2 (9.5%), respectively, had elevated baseline serum levels of IgG, IgM and IgA aCL antibodies. There was a dose-response relationship between risk of seizure and the baseline serum level of aCL antibodies (P < 0.01). The odds ratio of developing seizure were 3.7 for those who had a high level of aCL antibodies compared with those without a detectable level of aCL antibodies as the referent. Our results indicate that epilepsy as a primary neuropsychiatric event among lupus patients is associated with a high titer of aCL antibodies.

Population-based survey on prevalence of adult patients with epilepsy in Taiwan (Keelung community-based integrated screening no. 12)

PURPOSE To determine the prevalence rate and patterns of adult patients with epilepsy in Taiwan, we conducted a community-based neuroepidemiological survey. METHODS Epilepsy was detected by neurologists using one-stage method. It was integrated into a community health screening service and performed from 1 January 2001 to 31 December 2001 in Keelung, a northern city in Taiwan. A total of 13,663 subjects aged 30 years or older participated in this survey. RESULTS There were 52 patients with epilepsy in this study. Among them, 37 were patients with active epilepsy. The age-adjusted prevalence rate of active epilepsy above 30 years old was 2.77/1000 (to the 1980 US population) with the highest rate in subjects aged 40-49 years (4.0/1000). There was a trend of higher prevalence rate in male than in female. The most common seizure type was complex partial seizure (46.0%). Using one-stage detection method, we found nine (24.3%) patients with active epilepsy who had never been diagnosed before. Among the patients with active epilepsy, 35.1% were symptomatic cases. Head injury (13.5%) is the leading cause, followed by CNS infection (8.1%), stroke (5.4%) and perinatal insult (5.4%). The lifetime prevalence rate of epilepsy (including active epilepsy and epilepsy in remission) was 3.14/1000 for age above 30 years. CONCLUSIONS Comparing to previous epilepsy survey in 1993, our results showed that the prevalence rate of epilepsy was rather stable over the past decade in northern Taiwan. Head injury is the leading cause responsible for active epilepsy. Improving public safety is an important public health issue which may help to reduce occurrence of epilepsy.

Churg-Strauss syndrome presented as multiple intracerebral hemorrhage

Intracerebral hemorrhage is an uncommon sequel of Churg-Strauss syndrome. We describe a 27 y old Taiwanese male patient who was clinicopathologically diagnosed as Churg-Strauss syndrome. The patient experienced a sudden onset of blurring of vision and slowness of motion and speech. Magnetic resonance imaging of the brain revealed lobar hemorrhage on right parieto-occipital and left parietal areas. The cause of cerebral hemorrhage was probably due to poorly controlled high blood pressure and vasculitis. He received pulse therapy of methylprednisolone and cyclophosphamide followed by oral prednisolone. His neurological symptoms responded well to such a regimen. Cerebral hemorrhage is a major cause of morbidity and death in patients with Churg-Strauss syndrome. Uncontrolled high blood pressure may cause cerebral hemorrhage. Careful monitor of blood pressure is critical for the management of Churg-Strauss syndrome patients.

Imaging in the diagnosis and follow-up evaluation of vertebral artery dissection.

The purpose of this report is to discuss the value of ultrasonographic examination in the diagnosis and follow‐up evaluation of vertebral artery dissection. We collected data on 8 patients with 11 pathologic vessels: 9 were affected intracranially and 6 were affected extracranially. Four vessels were affected in both intracranial and extracranial segments. Extracranial color‐flow duplex sonography could detect abnormalities in every extracranial vertebral artery dissection. Most abnormal findings were non‐specific, including severely reduced flow, absence of flow, and absence of diastolic flow. A specific finding (intramural hematoma) was noted in one artery. Abnormal transcranial color‐coded sonographic findings included absence of flow, reduced velocity and reversed flow direction. Three intracranial dissecting arteries showed normal findings on transcranial color‐coded sonography. Ultrasonographic follow‐up study revealed evidence of improvement; this was noted almost exclusively in the extracranial segments of the vertebral artery but infrequently in the intracranial segment. Extracranial color‐flow duplex sonography is sensitive in the detection of extracranial vertebral artery dissection, both in initial diagnosis and in follow‐up evaluation.