Impact of informed consent on patient decisions regarding third molar removal.

PURPOSE: We investigated whether the order in which patients learned about complication risks affected their anxiety about and willingness to undergo the removal of their third molar. MATERIALS AND METHODS: In total, 171 patients (65 males, 106 females) were included in the study. The distributions of gender and the position of mandibular third molars were recorded. The Amsterdam Preoperative Anxiety and Information Scale and Spielberger's State-Trait Anxiety Inventory were used to evaluate anxiety. Associations of anxiety with timing (pre/post), gender, and the order in which the information was presented in the consent form were analyzed. RESULTS: The most common angulations were horizontal (26.3%) and mesioangular (60.2%), and these were more common in women. All patients obtained significantly higher anxiety scores after reading the consent form. There was no significant difference in anxiety scores, according to the order of information. In total, 88 patients underwent surgery, whereas 83 postponed the extraction after reading the consent form. Women were significantly more anxious than men before the procedure. Patients showed lower anxiety levels after the procedure (P < 0.05). CONCLUSION: Increased anxiety was not associated with the order in which information was presented in the informed consent form. However, the informed consent form itself was a major contributor to increased patient anxiety. Further studies regarding the contents of consent forms and their effects on patient anxiety and decisions regarding third molar removal are needed.

Manganese-enhanced MRI to evaluate neurodegenerative changes in a rat model of kainic acid-induced excitotoxicity.

PURPOSE: Manganese-enhanced magnetic resonance imaging (MEMRI) has been used to detect brain activity based on the ability of active neurons to take up manganese ions through calcium channels. Kainic acid (KA), an analog of excitotoxic glutamate, can elicit selective neuronal death in the brains of rodents, of which the pathological changes partially mimic neurodegeneration in the central nervous system. We used in vivo MEMRI to evaluate neurodegenerative changes in an excitotoxicity model induced by KA in rats. MATERIALS AND METHODS: Adult Sprague-Dawley rats (220-250 g) were injected with either KA or saline into the right lateral ventricle. Precontrast and postcontrast MEMRI sessions were obtained. Region of interest (ROI) analyses were performed on both injected (saline and KA) and contralateral (normal) sites in the hippocampal area. All brains were evaluated histologically following MEMRI. RESULTS: Analysis of percentage change in ROI intensities of T1-weighted fluid-attenuated inversion-recovery MR images in the hippocampal area revealed a significant difference between the KA-injected (ipsilateral) and contralateral sites (P = 0.008), whereas no significant difference was observed between the saline-injected and contralateral sites. Furthermore, there was a significant difference between ipsilateral sites of the saline-treated and KA-treated groups (P = 0.026). The histological results supported these findings. CONCLUSION: MEMRI is a simple and useful in vivo method for detecting neurodegenerative changes due to excitotoxicity in the rat brain. The development of a manganese-based contrast agent that can be safely used in humans is warranted to investigate neurological disorders.