Casey M. Chern

Learn More
We applied frequency domain analysis to detect and quantify spontaneous fluctuations in the blood flow velocity of the middle cerebral artery (MCAFV). Instantaneous MCAFV of normal volunteers was detected using transcranial Doppler sonography. Spectral and transfer function analyses of MCAFV and arterial blood pressure (ABP) were performed by fast Fourier(More)
This study evaluates the validity of the transfer function analysis of spontaneous fluctuations of arterial blood pressure (ABP) and blood flow velocity of the middle cerebral artery (MCAFV) as a simple, convenient method to assess human cerebral autoregulation in patients with carotid stenosis. Eighty-three consecutive patients with various degrees of(More)
BACKGROUND The incidence of syncope increases with age, while aging is also associated with increased arterial wave reflection. HYPOTHESIS The study was undertaken to determine whether increased arterial wave reflection is a predisposing factor of syncope. METHODS We recruited 38 patients (28 men and 10 women, mean age 57.2 +/- 20.3 years, range 17-87(More)
OBJECTIVES To test the hypothesis that vertebral artery hypoplasia (VAH) may affect the lateralisation of vestibular neuropathy (VN), probably through haemodynamic effect on the vestibular labyrinth. METHODS 69 patients with unilateral VN were examined with a magnetic resonance angiographic (MRA) and caloric test. 50 healthy subjects served as controls.(More)
This study evaluates the effect of orthostasis on the low frequency (LF, 0.04 to 0.15 Hz) fluctuations in the blood flow velocity of the middle cerebral artery (MCAFV) in relation to its arterial blood pressure (ABP) equivalent to further define and quantify this relationship in cerebrovascular regulation. Spectral analysis was performed on 22 healthy(More)
Acute febrile neutrophilic dermatosis (Sweet's syndrome) is an uncommon inflammatory cutaneous disorder. It presents with lesions which are tender, erythematous, edematous papules and under histologic examination show dense neutrophilic infiltration of the dermis. These lesions are often accompanied by leukocytosis and fever. This paper reports a unique(More)
BACKGROUND Measurement of CSF pressure is the only known way to confirm the diagnosis of intracranial hypotension. We aimed to assess colour doppler flow imaging (CDFI) for measurement of blood flow of the superior ophthalmic vein for the diagnosis of intracranial hypotension. METHODS We enrolled 25 consecutive patients with orthostatic headache who had(More)
BACKGROUND The aim of our study was to evaluate the effects of orthostatic stress produced by the head-upright tilt test on human cerebral hemodynamics by transcranial Doppler sonography. METHODS We studied 60 subjects who were divided into two groups; one of normal controls (n = 43) and one of patients suffering from syncope (n = 17). A 30-minute(More)
A total of 141 subjects with tight stenosis (> or = 75%) or occlusion of internal carotid artery were followed up at intervals 3-6 months regularly for 40 +/- 16 months. The direction of ophthalmic artery flow was used as a parameter of risk indicator on cerebral ischemic events. Eleven patients with bilateral carotid tight stenosis/occlusion were excluded(More)
Serum neutralizing antibodies for type 1, 2 and 3 poliovirus were studied in 15 Chinese patients in Taiwan with juvenile distal spinal muscular atrophy of the upper extremities and 15 age-matched normal subjects. Significantly lower serum antibody titers were found in the study group, suggesting that patients with this chronic focal form of acquired motor(More)