Han-Hwa Hu

Prevalence and Subtypes of Dementia in Taiwan: A community Survey of 5297 Individuals

OBJECTIVE: To study the prevalence rate of dementia in Taiwan, the relative frequencies of its subtypes, and its associations with age, education, gender, and residence location.

Incidence of stroke in Taiwan.

Background and Purpose: Few epidemiological studies concerning the incidence of stroke have been conducted in Taiwan. In an attempt to investigate this common disease, we studied the incidence of stroke in Taiwan in a prospective incidence study. Methods: A cohort of 8,562 stroke-free people were followed up for 4 years to observe new stroke occurrence. The methods of sampling the study population have been reported elsewhere. In addition to the help of local doctors, who reported the new stroke cases, we also sent public nurses to visit the study population annually to screen the new cases of stroke. Results: There were 104 (61 men and 43 women) first-ever stroke cases identified by a neurologist in a period between October 1, 1986 and December 31, 1990. The average annual incidence rate of first-ever stroke for people aged 36 years or older in this study was 330 per 100,000. Incidence rate was higher in eastern Taiwan and in rural communities. Percentages of the major types of stroke were as follows: cerebral infarction, 71%; cerebral hemorrhage, 22%; subarachnoid hemorrhage, 1%; and unclassified, 6%. The significant risk factors for stroke were hypertension and intake of food with a high sodium content. Conclusions: The age-specific incidence rates in this study are higher than those reported from the United Kingdom and the United States. The rates are close to those in a report from Japan and a report from a city in mainland China at the same latitude. Cerebral hemorrhages are more common among people in Taiwan than among Occidental people.

A Randomized Controlled Trial on the Treatment for Acute Partial Ischemic Stroke with Acupuncture

The effectiveness of acupuncture in acute stroke remains largely untested and unproved. A randomized, controlled trial was carried out to study the feasibility of acupuncture in combination with conventional supportive treatment for acute stroke patients. A total of 30 patients, aged 46-74, with the onset of symptoms within 36 h were enrolled into the study after appropriate screening. All patients gave informed consent. Basing on the same supportive treatment, patients were randomly assigned to a treatment with or without acupuncture. The procedure and acupoint selection were discussed and decided through several meetings of a group of senior acupuncture doctors in Taiwan. Acupuncture was applied 3 times/week for 4 weeks. During the study period, there were no problems in conducting this trial in terms of patient availability and acceptance, and physician cooperation. A significantly better neurologic outcome was observed in the acupuncture group on day 28 and day 90. The improvement in neurologic status was greatest in patients with a poor neurologic score at baseline. There were no important side effects except for one episode of dizziness related to acupuncture treatment. The data and results of this study will be used as a guideline for planning a full-scale clinical trial, e.g. sample size calculation, method of randomization with stratification of prognostic factors, choosing acupuncture points and technique of acupuncture.

Frequency and characteristics of early seizures in Chinese acute stroke

We retrospectively studied 1200 hospitalized acute strokes of all etiologies between July 1990 and August 1992. Ninety‐six % of all strokes underwent computed tomography of the head. Fifty‐eight percent of the 1200 strokes were brain infarction, 32% brain hemorrhage, 6% subarachnoid hemorrhage and 4% were other stroke subtypes. Thirty (2.5%) of all strokes suffered from early seizures. The incidences of early seizures were 2.8% in brain hemorrhage, 2.3% in brain infarction, 2.7% in subarachnoid hemorrhage and 2% in other stroke subtypes. Early seizures were documented in 6% of the patients with carotid territory cortical infarctions and 12% of the patients with lobar hemorrhage, whereas only 0.6% of the patients without carotid territory cortical infarctions and 0.6% of the patients without lobar hemorrhage were affected. Sixty‐ six percent of 30 early seizures were partial seizures, 24% generalized and status epilepticus were seen only in 10%. In conclusion, we found the early seizure incidence was 2.5% in Chinese patients hospitalized with acute strokes. There was no correlation between seizure occurrence and stroke subtypes. Early seizure developed significantly higher in acute stroke patients with lesions of the cortex than those patients without cortical involvement. The partial seizures were the most frequent type occurring in 66% of all acute stroke patients with early seizures.

Detection of intracranial venous reflux in patients of transient global amnesia

BACKGROUND The mechanism of transient global amnesia (TGA) is not clear. Attempting to support the hypothesis that retrograde venous hypertension causing cerebral venous ischemia plays a role in the pathogenesis of TGA, the authors used cranial three-dimensional time-of-flight (TOF) MR angiography (MRA) to detect a possible intracranial retrograde venous flow in TGA patients. METHODS The frequency of abnormal venous signals on cranial three-dimensional TOF MRA was compared in 10 TGA patients with the signals in 50 age- and gender-matched normal individuals. In TGA patients with abnormal venous signals, other examinations (cerebral digital subtraction angiography, upper extremity digital subtraction venography [DSV], and thoracic inlet MRI) were performed to elucidate the etiology of these abnormal intracranial venous flow patterns. RESULTS Abnormal venous signals on three-dimensional TOF MRA were found in five (50%) of the TGA patients and none of the control subjects (p < 0.001). Compression leading to occlusion of the left brachiocephalic vein by the sternum and aorta during regular breathing, as depicted by upper extremity DSV and thoracic inlet MRI, occurred consistently among these five TGA patients with abnormal venous signals. CONCLUSIONS Retrograde intracranial venous flow caused by left brachiocephalic vein occlusion was found only in patients with transient global amnesia (TGA). This result suggests that TGA patients may have an underlying impairment of cerebral venous outflow that increases their vulnerability to TGA attack.

Prevalence of stroke in Taiwan.

We investigated the prevalence of stroke in Taiwan in an epidemiologic study of stroke, diabetes, and cardiovascular disease that used a two-phase survey design. The study population was drawn by cluster sampling and consisted of both urban and rural communities from four regions of Taiwan. There were 8,705 people 36 years of age or older interviewed during the period of October 1 to December 31, 1986, and 143 cases of completed stroke were later identified by a neurologist. The point prevalence rate for people aged 36 or older in our study was 1,642/100,000 population (95% confidence interval 1,389-1,942/100,000). Prevalence rates differed significantly among the four study regions and between urban and rural communities; prevalence was greater in northern Taiwan and in urban communities. Percentages of the major types of stroke in 143 stroke survivors were as follows: cerebral infarction 67.1% (96 cases), cerebral hemorrhage 14.0% (20 cases), subarachnoid hemorrhage 4.2% (six cases), and unclassified 14.7% (21 cases). Of the stroke survivors, 67.1% were independent in activities of daily living, and 75.5% were independent in ambulation. Hypertension, heart disease, diabetes mellitus, and a family history of stroke were significantly more common in stroke survivors than in strokefree individuals.

Color Doppler imaging of orbital arteries for detection of carotid occlusive disease.

Background and Purpose Distal to a hemodynamically significant stenosis, the Doppler effect becomes dampened. Thus, measuring the flow profile in the ophthalmic artery and the central retinal artery with color Doppler imaging may provide hemodynamic information about the carotid circulation. Methods To validate the flow profile measurement withcolor Doppler imaging in the ophthalmic and central retinal arteries and to determine the sensitivity and specificity of this examination in the detection of hemodynamically significant carotid stenosis, we compared color Doppler imaging examinations with ocular pneumoplethysmography and ophthalmodynamometry examinations in 66 patients with athero-thrombotic ischemic cerebrovascular disease. The degree of carotid stenosis in these patients was determined by a duplex scan with color Doppler imaging, and 57 patients underwent angiography to verify the stenosis. Results The flow velocities (systolic peak velocity and end-diastolic velocity) and pulsatility indices (A/B ratio and resistance index) in the ophthalmic and central retinal arteries decreased as the degree of carotid stenosis increased. There is a statistically significant difference in the mean of systolic peak velocity and the mean of end-diastolic velocity of the ophthalmic and central retinal arteries among groups with various degrees of carotid stenosis (P<.02). Using the flow velocities of the ophthalmic and central retinal arteries to diagnose carotid stenosis (≥75% stenosis and occlusion), 8 cm/s for systolic peak velocity in the central retinal artery and 29 cm/s for systolic peak velocity plus flow direction reversal in the ophthalmic artery gave the maximum accuracy (sensitivities, 84% and 85.7% and specificities, 89.6% and 81.7%, respectively). The systolic peak velocity in the central retinal artery varied directly with the systolic pressure of the ophthalmic and central retinal arteries. Conclusions The flow velocity and pulsatility in orbital arteries examined by color Doppler imaging provide further hemodynamic information; this test can be used to complement current sonographic examination of carotid disease.

Reflux of jugular and retrobulbar venous flow in transient monocular blindness

Transient monocular blindness (TMB) attacks may occur during straining activities that impede cerebral venous return. Disturbance of cerebral and orbital venous circulation may be involved in TMB.

More severe white matter changes in the elderly with jugular venous reflux

The etiology of age‐related white matter changes is unclear. Cerebral white matter changes on magnetic resonance imaging (MRI) and progressive dementia have been reported in patients with dural arteriovenous fistulas of the sigmoid sinus. The frequency of jugular venous reflux, which mimics a dural arteriovenous fistula, significantly increases with age. We investigated whether jugular venous reflux was associated with the severity of age‐related white matter changes in 97 persons (aged 55–90 years, mean [standard deviation]: 75.77 [8.19] years; 55 men) from a medical center memory clinic.

Quality of life in elderly patients with dizziness: analysis of the short-form health survey in 197 patients

Conclusion Elderly patients with chronic dizziness had a poor HRQoL, which could be successfully assessed using the SF-36, a generic health-status instrument. The frequency of dizziness and comorbid psychological distress were predictive of impairment in QoL. Objectives To evaluate health-related quality of life (HRQoL) and its relationship to characteristics of dizziness in elderly persons with chronic dizziness. Material and methods A standardized dizziness questionnaire was used to evaluate characteristics of dizziness as well as medical, functional and demographic data in 197 consecutive patients with chronic dizziness aged≥60 years. HRQoL was evaluated using the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) and the Hospital Anxiety and Depression Scale (HADS). Results Compared with normative data, results from patients with dizziness indicated a pervasive multidimensional decline in SF-36 scores. This decline was most notable in terms of role limitations in the physical and emotional dimensions. The frequency of attacks of dizziness correlated with perceived disability. Patients with chronic dizziness also had great psychological distress, as measured by the HADS score, which had a detrimental influence on their QoL.