Long-Term Neurophysiological Outcomes in Patients Undergoing Coronary Artery Bypass Grafting

Abstract Introduction: This study aims to evaluate late postoperative neurophysiological outcomes in patients after coronary artery bypass grafting (CABG). Methods: Forty-five male patients with stable coronary artery disease aged 45-69 years underwent extended neuropsychological assessment using the software Status PF and electroencephalographical examination 3-5 days before CABG and 5-7 years after CABG. Postoperative decline in cognitive functions was determined by a 20% decrease in the cognitive indicator compared to that at baseline on 20% of the tests included in the Status PF battery. Statistical analysis was performed using the software STATISTICA 10.0. Multiple regression was used to identify demographic, clinical, and electroencephalographical variables associated with adverse cognitive outcomes. Results: Cognitive decline was observed in 54% of the patients in the long-term postoperative period. Five to seven years after CABG, all patients have shown an increase in the theta rhythm power compared to the preoperative values, which is most pronounced in the frontal and temporal areas of the right hemisphere (P=0.04), along with a decrease in the alpha rhythm in the posterior areas of the cortex (P=0.005). Multiple regression has reported that the main predictors of cognitive impairment are slower mean alpha frequency, decreased theta-2 rhythm with eyes closed in the right temporal area, and increased theta-2 rhythm with eyes open in the left temporal area (F(5.39)=8.81; P<0.00007; adjusted R-squared=0.57). Conclusion: Our findings indicate that 54% of the patients suffer from postoperative cognitive decline associated with increased theta and decreased alpha rhythms 5-7 years after CABG.

El impacto del tratamiento de la encefalopatía hepática mínima en el pronóstico a largo plazo / The impact of minimal hepatic encephalopathy treatment in long-term prognosis

La encefalopatía hepática mínima (EHm) afecta del 30% al 50% de los pacientes cirróticos. Su detección es esencial por su relación con la encefalopatía hepática clínica, la alteración de la habilidad para conducir, el mayor riesgo de caídas, la alteración de la calidad de vida, la progresión más acelerada de la cirrosis y la supervivencia. A pesar de la información fidedigna de su relevancia clínica, pronóstica y social, la detección de EHm no está generalizada en la práctica clínica. El espectro de la encefalopatía hepática engloba diversas alteraciones de las funciones cerebrales, por lo que se requiere realizar más de un test para su diagnóstico. Además, las alteraciones iniciales difieren de un paciente a otro. Esto ha dificultado el desarrollo de una estrategia diagnóstica universal. Como resultado, no disponemos de datos suficientes para generar recomendaciones basadas en la evidencia del impacto del tratamiento de la EHm en la calidad de vida y la supervivencia, así como de su rentabilidad. Por lo tanto, las guías clínicas actuales sugieren que se evalúe la EHm cuando se afecta la calidad de vida de los pacientes, ya que no se conocen las consecuencias del tamizaje. Las terapias reductoras de amonio se consideran la piedra angular del tratamiento de la EHm. Los disacáridos no absorbibles, la rifaximina y, más recientemente, los probióticos, han mostrado efectos beneficiosos. Se necesitan más ensayos controlados con placebo para evaluar la eficacia, seguridad y rentabilidad de los regímenes de tratamiento disponibles para evaluar el impacto del tratamiento de la EHm en el pronóstico a largo plazo de estos pacientes.

Minimal hepatic encephalopathy (MHE) affects up to 30-50% of cirrhotic patients. The detection of MHE is essential because of its relationship with overt hepatic encephalopathy, impairment of motor vehicle driving abilities, higher risk of falls, quality of life impairment, faster cirrhosis progression and survival. Despite the robust evidence regarding its clinical, prognostic and social relevance, MHE testing is not widespread in routine clinical care. Hepatic encephalopathy spectrum covers various alterations in complex brain functions, requiring more than one test to be quantified. In addition, initial disturbances differ from one patient to another. All this has made it difficult to develop a universal diagnostic strategy. As a consequence, there is a lack of available robust data in the literature to generate evidence-based recommendations related to the impact of MHE treatment on quality of life and survival of these patients, as well as on cost-effectiveness. Therefore, current clinical guidelines suggest MHE testing only when patients have problems with their quality of life, since consequences of the screening procedure are still unclear. Ammonia lowering therapies have been considered the cornerstone of MHE treatment. Beneficial effects of non-absorbable disaccharides (lactulose or lactitol), rifaximin and more recently, probiotics have been reported. Further placebo-controlled trials are needed to assess the efficacy, safety, and cost-effectiveness of available treatment regimes to evaluate the impact of MHE treatment on the long-term prognosis of these patients.

Reliability and Validity of the Severe Impairment Battery (SIB) in Korean Dementia Patients

This study was conducted to examine the reliability, validity and clinical utility of the Severe Impairment Battery (SIB) for a Korean population. 69 dementia patients with Clinical Dementia Rating (CDR) stages 2 or 3 were participated in this study. The SIB, Korean version-Mini Mental State Examination (K-MMSE), CDR, and Seoul-Activities of Daily Living (S-ADL) were administered. The validity of the SIB was confirmed by evaluating the correlation coefficients between the SIB and K-MMSE, CDR, S-ADL, which were found to be significant. Cronbach's alpha for the total SIB score and each subscale score showed high significance, and the item-total correlation for each subscale was also acceptable. The test-retest correlation for the total SIB score and subscale scores were significant, except for the praxis and orienting to name. The total SIB score and subscale scores were examined according to CDR. The results suggest that the SIB can differentiate the poor performances of severely impaired dementia patients. On the basis of the receiver operating characteristic (ROC), it can be concluded that the SIB is able to accurately discriminate between CDR 2 and 3 patients. The results of this study suggest that the SIB is a reliable and valid instrument for evaluating severe dementia patients in Korean population.