Michael C. Lee

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Although laser-evoked electroencephalographic (EEG) responses are increasingly used to investigate nociceptive pathways, their functional significance remains unclear. The reproducible observation of a robust correlation between the intensity of pain perception and the magnitude of the laser-evoked N1, N2, and P2 responses has led some investigators to(More)
Evidence from behavioral and self-reported data suggests that the patients' beliefs and expectations can shape both therapeutic and adverse effects of any given drug. We investigated how divergent expectancies alter the analgesic efficacy of a potent opioid in healthy volunteers by using brain imaging. The effect of a fixed concentration of the μ-opioid(More)
CONTEXT Establishing a neurobiological account of delusion formation that links cognitive processes, brain activity, and symptoms is important to furthering our understanding of psychosis. OBJECTIVE To explore a theoretical model of delusion formation that implicates prediction error-dependent associative learning processes in a pharmacological functional(More)
Functional neuroimaging studies in humans have shown that nociceptive stimuli elicit activity in a wide network of cortical areas commonly labeled as the "pain matrix" and thought to be preferentially involved in the perception of pain. Despite the fact that this "pain matrix" has been used extensively to build models of where and how nociception is(More)
Pain is a highly subjective experience that can be substantially influenced by differences in individual susceptibility as well as personality. How susceptibility to pain and personality translate to brain activity is largely unknown. Here, we report that the functional connectivity of two key brain areas before a sensory event reflects the susceptibility(More)
Opioid receptors are known to undergo complex regulatory changes in response to ligand exposure. In the present study, we examined the effect of morphine on the in vitro and in vivo density and trafficking of delta opioid receptors (deltaORs). Prolonged exposure (48 hr) of cortical neurons in culture to morphine (10 microm) resulted in a robust increase in(More)
Nociception begins when Adelta- and C-nociceptors are activated. However, the processing of nociceptive input by the cortex is required before pain can be consciously experienced from nociception. To characterize the cortical activity related to the emergence of this experience, we recorded, in humans, laser-evoked potentials elicited by physically(More)
PURPOSE To study and report the clinical outcomes and patterns of failure after intensity-modulated radiotherapy (IMRT) for nasopharyngeal carcinoma (NPC). METHODS AND MATERIALS The treatment outcomes of NPC patients treated with IMRT at Pamela Youde Nethersole Eastern Hospital between 2005 and 2007 were reviewed. The location and extent of locoregional(More)
PURPOSE To evaluate a multislice nonlinearly-spaced 12-echo imaging sequence at 3T covering the supratentorial brain for the quantification of myelin water fraction (MWF) in multiple sclerosis (MS) patients. METHODS Eighty-nine patients with, or at risk of, MS (69 relapsing remitting MS [RRMS], 7 secondary progressive MS [SPMS], 13 clinically isolated(More)
PURPOSE To study the prognostic significance of primary tumor volume on local control of nasopharyngeal carcinoma. METHODS AND MATERIALS Between 1998 and 2001, 308 consecutive patients with nasopharyngeal carcinoma treated with radical intent were staged with MRI. On the basis of the extent of tumor infiltration outlined by a diagnostic radiologist, the(More)