Experience-dependent plasticity: differential changes in activation associated with repeated reinforcement.

Experience-dependent change in blood-oxygen-level-dependent (BOLD) signal is increasingly being employed in neuroimaging research to examine questions about function and plasticity. In this investigation, plasticity was examined during consecutive visual cue presentations that preceded correct button presses and subsequent reinforcer deliveries. Using functional neuroimaging and a modified repeated acquisition methodology, 10 adult subjects learned, through trial and error, a series of novel cue-response-reinforcer relations. Separate BOLD responses were obtained to consecutive cues and reinforcers. Repeated measures analysis of variance highlighted differential BOLD response changes. Consecutive visual cue presentations elicited rapid bilateral increases in activation in the anterior cingulate and medial frontal gyrus and moderate increases in medial temporal lobe structures and the striatum. Consecutive reinforcer presentations elicited rapid increases in activation in the left precuneus, lingual and fusiform gyri and moderate increases in medial temporal lobe structures and striatum. Within the medial temporal lobe, cues elicited a gradual increase then an abrupt decrease in activation and rewards elicited abrupt and then sustained activation. Consideration of experience-dependent BOLD response change and variability provides basic research a new perspective from which to examine regional plasticity and further explore dynamic experience-dependent shifts among cognitive processes. Furthermore, BOLD change and variability offer many clinical research areas novel supplemental indices of neuropathology.

Post-fundoplication symptoms: the role for endoscopic assessment of fundoplication integrity.

BACKGROUND: Fundoplication is now almost exclusively a laparoscopic procedure. The aim of this study was the comparison of the diagnostic usefulness of endoscopy and barium esophagram in the detection of fundoplication abnormalities. METHODS: Twenty-two patients presented with symptoms post-laparoscopic (Nissen) fundoplication that included dysphagia (14 patients), heartburn (5 patients), dyspepsia (2 patients), and chest pain (1 patient). Barium esophagram and upper endoscopy were performed in all patients and the results were compared. Key features included presence of esophagitis, resistance to endoscope passage, location of the wrap relative to the diaphragmatic hiatus, location of squamocolumnar junction greater than 1 cm proximal to the wrap zone, and the appearance of the wrap (intact, loose, disrupted, or tight). RESULTS: The key features explained symptoms in 20 of 22 patients. Endoscopy detected twice as many key features as radiography. Disruption of the wrap or excessive proximal location of the squamocolumnar junction proximal to the wrap zone were the most incriminating endoscopic findings. Resistance to endoscope passage was rarely encountered and the esophagram was more accurate in detecting an overly tight wrap. CONCLUSIONS: Endoscopic evaluation is more accurate than barium esophagram in detecting post-fundoplication abnormalities. The appearance of the fundoplication wrap and an abnormal proximal location of the squamocolumnar junction appear to be major endoscopic clues in diagnosis of post-fundoplication problems.

Esophageal disorders in the elderly.

As the number of elderly in the population increases, decompensation of swallowing and airway protective mechanisms can create an increased health care burden. This article outlines the effect of aging on deglutitive function and esophageal and aerodigestive reflexes. Specific disorders in the elderly are discussed.

Videoendoscopic evaluation of supraesophageal dysphagia.

Oropharyngeal dysphagia is a cause of major morbidity and mortality, particularly in the ever-increasing aged population, following stroke, or after extensive head and neck surgery such as for cancer. Videoendoscopy has become a useful tool in the evaluation and treatment of oropharyngeal dysphagia, and it is particularly suited to patients who may be unable to tolerate videofluoroscopy. This paper reviews the current literature regarding the technique of videoendoscopic evaluation and outlines various indications for its use.

Does open access endoscopy close the door to an adequately informed patient?

BACKGROUND: The use of open access endoscopy is increasing. Its effect on the adequacy of patient informed consent, procedure acceptance and the impact on subsequent communication/transfer of procedure results to the patient have not been evaluated. The aim of our study was to compare the extent of preknowledge of procedures and test explanation, patient medical complexity, information transfer and overall patient satisfaction between a patient group referred for outpatient open access endoscopy versus a patient group from a gastrointestinal (GI) subspecialty clinic. METHODS: Information was obtained from all patients presenting for outpatient upper and lower endoscopy by using a 1-page questionnaire. Patients from the two groups who had an outpatient upper/lower endoscopic procedure were contacted by phone after the procedure to obtain information with a standardized questionnaire. RESULTS: The open access patients reported receiving significantly less information to help them identify the procedure (p < 0.01) and less explanation concerning the nature of the procedure than the group of patients referred from the subspecialty clinic (p < 0.005). There was no difference between the two groups in satisfaction scores for examinations performed under conscious sedation. For flexible sigmoidoscopy without sedation, however, the GI clinic patient group were more satisfied with their procedure. The majority of patients, regardless of access, were more likely to receive endoscopic results from a gastroenterologist than the referring physician. Furthermore, the patients in the GI clinic group who underwent colonoscopy felt significantly better at follow-up. CONCLUSIONS: Patients undergoing open access procedures are less likely to be properly informed about their endoscopic procedure. Our results indicate that with open access endoscopy, a defined mechanism needs to be in place for communication of endoscopic results to the patient.