Facial skin temperature in acute stroke patients with delirium - A pilot study.

Facial skin temperature depends strongly on blood flow in small blood vessels in the skin. These are regulated by the sympathetic part of the autonomic nervous system. Delirium may pathophysiologically be associated to changes in the sympathetic part of the autonomic nervous system. In this observational study, we evaluated the influence of various exogenous and endogenous covariables on the regional facial temperatures in acute stroke patients with and without delirium. Facial thermography (FT) was performed using an infrared digital camera. Screening for delirium was done using the Confusion Assessment Method (CAM). Sixty-four patients were enrolled. Eight patients developed delirium. Sex and body temperature were positively associated to facial skin temperature, and so was ambient temperature but to an overall lesser magnitude. Stroke severity, diabetes, infection, facial palsy, facial sensory deficit, and physical activity did not influence facial skin temperature. Overall, there was no association between facial temperature and the occurrence of delirium except in one facial region, the medial palpebral commissure.

Changes in autonomic tone during delirium in acute stroke patients assessed by pupillometry and skin conductance.

Delirium is a common complication in acute ischemic stroke, possibly caused by alterations in the regulation of the sympathetic autonomic nervous system. We investigated whether such an association could be demonstrated with two easy-to-use measurement techniques: Measurement of palmar skin conductance level (SCL) and pupillometry measuring the dilation velocity in the pupillary light reflex (PLRdil.vel.). The cohort study included 64 patients admitted with acute ischemic stroke. During the study period (median 4.1 days, interquartile range 2.1 days) patients were assessed for delirium once daily as well as with measurements of SCL and PLRdil.vel up to twice daily. SCL and PLRdil.vel. during delirium were lower than without delirium present. For SCL the unadjusted difference was -40.8% (95% CI (-55.1 to -22.0), P value <.001) and for PLRdil.vel the unadjusted difference was -0.22 mm/s (95% CI (-0.42 to -0.01), P value = .041). The results demonstrate changes in sympathetic autonomic nervous system regulation during delirium in acute stroke patients.