0075 Neural Correlates of Cognitive Fatigue in Parkinson Disease

Introduction

Parkinson’s disease (PD) is a common neurodegenerative disease affecting millions of people world-wide. Fatigue is a prevalent and debilitating non-motor symptom in PD. However, the neural correlates underlying cognitive fatigue are poorly understood. Our previous studies suggested that continuous performance of a simple but mentally demanding psychomotor vigilance task (PVT) induced cognitive fatigue, operationalized as subjective exhaustion and time-on-task performance decline. Here we used arterial spin labeling (ASL) perfusion fMRI to investigate regional cerebral blood flow (CBF) changes in PD patients during cognitive fatigue induced by continuous performance of 20-min PVT.

Methods

Twenty-one PD patients completed a 20-min PVT during the ASL scan and two additional 4-min resting-state ASL scans before and after PVT. Reaction times (RTs) and regional CBF changes throughout the PVT as well as during pre- and post-task resting baselines were measured. Cognitive fatigue was analyzed by dividing the entire PVT performance into five quintiles in addition to the immediate measurement of self-rated fatigue before and after PVT.

Results

PD patients demonstrated significantly increased self-reported fatigue ratings after the task (p < 0.05) and progressively slower RTs across quintiles (p < 0.05). Perfusion data showed that the PVT activates the right middle frontal cortex, right inferior parietal lobe, right insula, bilateral occipital cortex, and right cerebellum (FDR corrected). Moreover, the bilateral middle frontal gyri were less active during the post-task rest compared to the pre-task rest.

Conclusion

These results demonstrated that cognitive fatigue has an ongoing effect on brain activity after a period of continuous mental effort and supported the critical role of prefrontal cortex in mediating cognitive fatigue in PD. The findings also suggest the utility of continuous PVT as an appropriate paradigm to induce and examine cognitive fatigue in PD.

Support

Supported in part by Parkinson’s Foundation Translational Research Grant and NIH grants R01-MH107571, R21-AG051981, and P30-NS045839.

Focused cardiac ultrasound is feasible in parturients; a prospective observational study

BACKGROUND

In pregnancy, the major causes of morbidity and mortality include diseases that affect circulation profoundly and restoration of normal circulation is a key objective. Focused cardiac ultrasound provides information on the individual determinants of circulation and has a significant impact on patient management. This study aimed to determine the feasibility of focused cardiac ultrasound in term parturients.

METHODS

Forty parturients underwent focused cardiac ultrasound. Parasternal long-axis, parasternal short-axis, 4-chamber and subcostal views were performed in the left-lateral position and the supine position by a novice operator. All images were graded on the following scale: 1 = no image; 2 = poor and insufficient image; 3 = sufficient image quality; 4 = good image quality; 5 = perfect image quality. A cut-off grade of three signified images sufficient for clinical decision-making.

RESULTS

Images sufficient for clinical decision-making were obtained in all patients when including all imaging views. 37/40 (93 %) patients presented images of grade ≥ 4, whereas 10/40 (25%) patients had images of grade 5. Image grades were higher in the left lateral position (all P < 0.001). Parturients with a body mass index ≤ 30 kg/m² did not present different image grades than parturients with a higher body mass index (P = 0.753). Subcostal views could not be obtained.

CONCLUSION

Focused cardiac ultrasound is feasible in the obstetric population and images of sufficient quality for clinical decision-making were obtained in all parturients by an operator with limited experience.

Sufentanil preserves hemodynamics and left ventricular function in patients with ischemic heart disease

OBJECTIVE

Sufentanil has been reported to provide stable hemodynamics similar to other opioids. However, it has not been reliably established whether this stability can be attributed only to Sufentanil and translates into fully preserved left ventricular (LV) function. The purpose of this study was to evaluate the effect of Sufentanil on hemodynamics and LV systolic and diastolic function using invasive monitoring and echocardiography in patients with ischemic heart disease.

METHODS

Prospective observational study of thirty patients acting as their own control undergoing echocardiographic imaging before and after bolus Sufentanil 1.5-2.0 μg/kg. Full invasive hemodynamic monitoring was established before Sufentanil administration. Global LV systolic function was evaluated with a global longitudinal peak systolic strain (GLPSS) by speckle tracking ultrasound; systolic displacement by tissue tracking (TT) and diastolic function was evaluated using Doppler tissue imaging and pulse wave Doppler.

RESULTS

Hemodynamic monitoring showed a minor decline in systolic blood pressure from 159 to 154 mmHg (P=0.046). No changes were observed in the cardiac index, stroke volume index and heart rate. An unchanged TT score index (9.9 vs. 10.2 mm, P=0.428) and GLPSS (14.3 vs. 14.5%, P=0.658) indicated preserved LV global systolic function and unchanged E'/A' (0.95 vs. 0.89, P=0.110) and E/E' ratio (15.4 vs. 14.9, P=0.612) indicated unchanged diastolic function.

CONCLUSION

Sufentanil preserves hemodynamic parameters as well as echocardiographic indices of LV systolic and diastolic function in patients with ischemic heart disease (IHD).