Ching-Kuan Liu

Obstructive sleep apnea (OSA) has been associated with cognitive decline via several mechanisms, including intermittent hypoxemia, sleep fragmentation, and neuroinflammation. The neurological consequences of OSA have evolved into a major biopsychosocial concern in the elderly, especially memory impairment. We aimed to identify the polysomnographic (PSG) parameters capable of predicting memory impairment among OSA patients at or over age 50 with OSA. We reviewed the 10-year electronic medical records of OSA patients and compared the initial PSG parameters between those presenting and not presenting self-reported memory impairment. We conducted subgroup analyses based on OSA severity and performed multivariate analysis to correlate PSG parameters with memory impairment. The result showed that 25 out of the 156 (16%) investigated patients experienced self-reported memory impairment during follow-up. As compared to OSA patients without self-reported memory impairment, those reported with self-reported memory impairment had a higher oxygen desaturation index (ODI) (23.9 ± 17.8 versus 18.2 ± 12.0, p = 0.048). Regarding the associations between apnea-hypopnea index (AHI) as well as ODI and self-reported memory impairment among OSA subgroups classified by severity, the associations were only evident in the severe OSA subgroup in both univariate (p < 0.001; p = 0.005) and multivariate analyses (p = 0.014; p = 0.018). We concluded that AHI and ODI are the most relevant PSG parameters in predicting memory impairment in severe OSA patients.

Epidemiologic studies have indicated that dyslipidemia may facilitate the progression of neuronal degeneration. However, the effects of chronic dyslipidemia on brain function, especially in older individuals, remain unclear. In this study, middle-aged 37-week-old male Wistar-Kyoto rats were fed a normal diet (ND) or a 45% high-fat diet (HFD) for 30 weeks (i.e., until 67 weeks of age). To study the effects of chronic dyslipidemia on the brain, we analyzed spontaneous locomotor activity, cognitive function, and brain tissues in both groups of rats after 30 weeks. Compared with age-matched rats fed a ND, Wistar-Kyoto rats fed a HFD had dyslipidemia and showed decreased movement but normal recognition of a novel object. In our brain analyses, we observed a significant decrease in astrocytes and tyrosine hydroxylase–containing neurons in the substantia nigra and locus coeruleus of rats fed a HFD compared with rats fed a ND. However, hippocampal pyramidal neurons were not affected. Our findings indicate that the long-term consumption of a HFD may cause lipid metabolism overload in the brain and damage to glial cells. The decrease in astrocytes may lead to reduced protection of the brain and affect the survival of tyrosine hydroxylase–containing neurons but not pyramidal neurons of the hippocampus.

Multi-class classification is a very important technique in engineering applications, e.g., mechanical systems, mechanics and design innovations, applied materials in nanotechnologies, etc. A large amount of research is done for single-label classification where objects are associated with a single category. However, in many application domains, an object can belong to two or more categories, and multi-label classification is needed. Traditionally, statistical methods were used; recently, machine learning techniques, in particular neural networks, have been proposed to solve the multi-class classification problem. In this paper, we develop radial basis function (RBF)-based neural network schemes for single-label and multi-label classification, respectively. The number of hidden nodes and the parameters involved with the basis functions are determined automatically by applying an iterative self-constructing clustering algorithm to the given training dataset, and biases and weights are derived optimally by least squares. Dimensionality reduction techniques are adopted and integrated to help reduce the overfitting problem associated with the RBF networks. Experimental results from benchmark datasets are presented to show the effectiveness of the proposed schemes.

Rivastigmine is a cholinesterase inhibitor, approved for the treatment of mild-to-moderate dementia of Alzheimer’s type. This study assessed the short- and long-term effectiveness and safety of rivastigmine in patients with mild-to-moderate Alzheimer’s disease (AD) in a real-world clinical setting in Taiwan.

Incidence of dementia is growing rapidly and affects many people worldwide. Type 2 diabetes mellitus (DM) might link cognitive decline and dementia, but the reasons for this association remain unclear. Our study explored the factors associated with type 2 DM in patients with dementia. Patients (n = 40,404) with vascular dementia were identified in Taiwan’s 1997 to 2008 National Health Insurance Research Database and divided into a DM group and non-DM group. Eleven comorbidities were identified and categorized into four groups: cardiovascular and cerebrovascular diseases, digestive system diseases, renal and metabolic system diseases, and cancer. The associations of these factors with type 2 DM were explored through multivaraible logistic regression. Of the patients with dementia, 22.5% had DM. Associated with a higher likelihood of DM in this population were female sex (adjusted odds ratio [OR]: 1.44, 95% confidence interval [CI]: 1.36–1.52), young age (range of adjusted OR: 0.55–1.13), low income (range of adjusted OR: 1.09–1.18), and renal and metabolic system diseases (OR: 2.81, 95% CI: 2.64–2.98). The findings of this study suggest that clinicians should encourage patients with dementia to receive regular glucose impairment screening if they are female, have low socioeconomic status, or have renal or metabolic diseases.

Frontal lobes are great and are a late‐developing region of the neocortex that play a critical role in human behavior and executive function. The aim of this study was to clarify the role of event‐related potentials (ERPs) in executive dysfunction and its relationship between generator mechanism and cognitive significance. We recruited 20 patients with frontal lobe lesion (FLL) and 27 age‐matched controls. All patients submitted to comprehensive Frontal Test Battery and auditory ERPs measurement. In comparison with controls, the patients with FLL had significantly decreased executive function and manifested the delay of P300 latency, which reflected a delay of mental processing speed in these patients. Our findings suggest that patients with FLL may have prolonged P300 latency, which has a good correlation with executive dysfunction, poor performance, and longer P300 latencies. P300 ERPs are considered to be a useful method to identify the alteration of frontal‐parietal connection.

Early diagnosis and treatment of central nervous system (CNS) tuberculosis (TB) are very important because of its high morbidity and mortality characteristics. However, the clinical symptoms, laboratory and neuroimaging findings of CNS TB are nonspecific, no matter whether they are the common form, tuberculous meningitis (TBM), or the rare form, intracranial tuberculomas. We report a case of TBM with miliary pattern of intracranial tuberculomas, although the initial diagnosis was masked by an atypical neuropsychiatric presentation, cerebrospinal fluid (CSF) finding, and other medical comorbidity. A 51-year-old man was brought to the emergency room due to a traffic accident. The initial impression was Wernicke encephalopathy due to his alcohol use history and the clinical triad. After admission, fever and mental confusion lead to the suspicion of CNS infection. Although the initial CSF analysis was inconclusive, the miliary pattern of intracranial tuberculomas was highly suspected by brain magnetic resonance imaging finding. The diagnosis of TBM and miliary TB was finally confirmed by positive CSF and sputum culture of Mycobacterium tuberculosis. The patient had a good response to standard antituberculous therapy, although paradoxical expansion of cerebral tuberculomas occurred during treatment. TB is still a major public health problem in the world, and there is a rising tendency of extrapulmonary TB incidences in the developed countries. Because of the high mortality and treatable characteristics of CNS TB, physicians should be familiar with it and keep the diagnosis in mind.