Small ischemic brain lesions after cardiac valve replacement detected by diffusion-weighted magnetic resonance imaging: relation to neurocognitive function.

OBJECTIVE: Following coronary artery bypass graft surgery, some studies using magnetic resonance imaging (MRI) have demonstrated new small ischemic brain lesions in patients without apparent neurological deficits. We aimed to prospectively evaluate brain injury after cardiac valve replacement using MRI and to determine the relationship to neurocognitive function. METHODS: Thirty patients with a mean age of 64.9+/-9.8 years (range, 32-82, 12 female) receiving cardiac valve replacement (aortic valve replacement [AVR], n = 24; mitral valve replacement [MVR], n = 2; AVR and MVR, n = 2; AVR and mitral valve repair, n = 2) were investigated. Study protocol included neurological examination, comprehensive neuropsychological assessment and diffusion-weighted (DW) MRI. The investigations were performed before surgery and 5 days and 4 months after surgery. RESULTS: Postoperative DW MRI detected new focal brain lesions in 14 patients (47%). No patient revealed a focal neurological deficit. Six patients (43%) had multiple (> or = 3) lesions (range, 1-7). Lesion volume ranged from 50-500 mm3 except 1 territorial infarct of 1900 mm3. Of a total of 41 lesions, 27 (66%) were located in the right hemisphere and 32 in a subcortical location. By 5 days postoperatively, significant neurocognitive decline was observed in 5 of 13 tests affecting memory, attention and rate of information processing. By 4 months, dysfunction had recovered in all cognitive areas. The presence of new ischemic lesions was not associated with neurocognitive decline at discharge. There was also no significant correlation between clinical and operative variables and the presence of new DW lesions or neuropsychological outcome. CONCLUSIONS: Following cardiac valve replacement, new small ischemic brain lesions were detected by diffusion-weighted MRI. Neurocognitive decline was present early after operation, but resolved within 4 months. A correlation of new ischemic lesions to postoperative cognitive dysfunction or clinical variables was not found.

Evaluation of brain injury after coronary artery bypass grafting. A prospective study using neuropsychological assessment and diffusion-weighted magnetic resonance imaging.

OBJECTIVE: Neurocognitive dysfunction is a common complication after cardiac surgery with cardiopulmonary bypass (CPB). Studies using magnetic resonance imaging (MRI) have demonstrated that new focal brain lesions can occur after coronary artery bypass grafting (CABG), even in patients without apparent neurological deficits. Diffusion-weighted MRI is superior to conventional MRI and allows for sensitive and early detection of ischemic brain lesions. We prospectively investigated cerebral injury early and 3 months after CABG using diffusion-weighted MRI and related the findings to clinical data and neurocognitive functions. METHODS: Twenty-nine patients [67.6+/-8.6 (52-85) years, 5 females] undergoing elective CABG with CPB were examined before surgery, at discharge and 3 months after surgery. A battery of standardized neuropsychological tests and questionnaires on depression and mood were administered. Conventional and diffusion-weighted MRI of the brain was performed and new lesions were analyzed. Clinical characteristics, neuropsychological test performance and radiographic data were collected and compared. RESULTS: There was no major neurological complication after CABG. Thirteen patients (45%) exhibited 32 new ischemic lesions on postoperative diffusion-weighted MRI. The lesions were small, rounded and equally dispersed in both hemispheres. Eight patients had at least two lesions. At discharge, significant deterioration of neuropsychological performance was observed in 6 of the 13 tests compared to baseline assessment. By 3 months postoperatively, 5 of the 6 tests returned to preoperative levels. Verbal learning ability, however, remained impaired. The presence of new focal brain lesions was not associated with impaired neuropsychological performance. There was also no correlation between clinical variables, intraoperative parameters and postoperative complications and MRI findings. CONCLUSIONS: Although neurocognitive decline after CABG is mostly transient, memory impairment can persist for months. New ischemic brain lesions on postoperative diffusion-weighted MRI do not appear to account for the persistent neurocognitive decline.

Prevention of medication overuse in patients with migraine.

This multi-center study compared the therapeutic effect of a cognitive-behavioral minimal contact program (MCT) to the effect of a brochure (bibliotherapy) for the prevention of medication overuse headache (MOH) in migraine patients. Seven German headache centers recruited 182 migraine patients with high triptan or analgesic intake frequency. Patients were randomly allocated to either the MCT-group, receiving both an MCT program and an educational brochure or to the biblio-group receiving only the brochure. All participants continued usual medical treatment. Course of headaches, intake of analgesics or triptans after training, 3 months post-training as well as 1-2 years (mean 15.7 months) later and psychological variables were defined as outcome variables. A significant decline was observed in the number of headache days (11.0-8.8), migraine days (7.3-5.7) and medication intake days (7.4-6.1) from pre to post in the MCT-group (p<0.001 each) and in the biblio-group (p<0.001 each). The pre-to-post-improvements were maintained from pre- to short- and from pre- to long-term follow-up (p<0.001 each) in both groups. Both groups improved significantly from pre to post in psychological variables, e.g. pain acceptance: p<0.001; pain catastrophizing: p<0.001; functional pain coping: p<0.001; and pain related internal control beliefs: p<0.01. Psychological improvements remained stable in both groups at short- and long-term follow-up. During the study, none of the patients developed an MOH. MCT- and bibliotherapy are useful in migraine patients to prevent medication overuse headache or the transition of episodic to chronic headache.

Cognitive outcomes three years after coronary artery bypass surgery: relation to diffusion-weighted magnetic resonance imaging.

BACKGROUND: Cognitive decline is well recognized early after coronary artery bypass graft surgery (CABG), but controversy exists regarding the degree and duration of these changes. We investigated the course of cognitive performance during 3 years after surgery and determined whether ischemic brain injury detected by diffusion-weighted magnetic resonance imaging was related to cognitive decline. METHODS: Thirty-nine patients undergoing on-pump CABG completed preoperative neuropsychologic examination and were followed up prospectively at discharge, 3 months, and 3 years after surgery. Cognitive performance was assessed with a battery of 11 standardized psychometric tests assessing 7 cognitive domains. Cognitive outcome was analyzed by determining (1) mean changes in within-patient scores over time (identifying cognitive functions with decline), and (2) the incidence of cognitive deficit for each individual (identifying patients with decline). Objective evidence of acute cerebral ischemia was obtained by diffusion-weighted magnetic resonance imaging. Prospectively collected data were used to identify predictors of cognitive deficits. RESULTS: From baseline to discharge, cognitive test scores significantly declined in 7 measures. Most tests improved by 3 months. Between 3 months and 3 years, late decline was observed in 2 measures with persistent deterioration in 1 measure (verbal memory) relative to baseline. Postoperative cognitive deficits (drop of > or = 1 SD in scores on > or = 3 tests) were observed in 56% of patients at discharge, 23% at 3 months and 31% at 3 years. On postoperative diffusion-weighted magnetic resonance imaging, there were new ischemic cerebral lesions in 51% of patients. The presence of cognitive deficit at discharge was a significant univariate predictor of late cognitive decline (p = 0.025). A relation between the presence of new diffusion-weighted magnetic resonance imaging detected lesions and cognitive decline, however, was not found. CONCLUSIONS: Longitudinal cognitive performance of patients with CABG showed a two-stage course with early improvement followed by later decline. Long-term cognitive deficit was predicted by early cognitive decline, but not by ischemic brain lesions on magnetic resonance imaging.