Daugherty, Wilson P.

Object Near-infrared spectroscopy (NIRS) offers noninvasive bedside measurement of direct regional cerebral arteriovenous (mixed) brain oxygenation. To validate the accuracy of this monitoring technique, the authors analyzed the statistical correlation of NIRS and CT perfusion with respect to regional cerebral blood flow (CBF) measurements. Methods The authors retrospectively reviewed all cases in which NIRS measurements were obtained at a single, academic neurointensive care unit from February 2008 to June 2011 in which CT perfusion was performed at the same time as NIRS data was collected. Regions of interest were obtained 2.5 cm below the NIRS bifrontal scalp probe on CT perfusion with an average volume between 2 and 4 ml, with mean CBF values used for purposes of analysis. Linear regression analysis was performed for NIRS and CBF values. Results The study included 8 patients (2 men, 6 women), 6 of whom suffered subarachnoid hemorrhage, 1 ischemic stroke, and 1 intracerebral hemorrhage and brain edema. Mean CBF measured by CT perfusion was 61 ml/100 g/min for the left side and 60 ml/100 g/min for the right side, while mean NIRS values were 75 on the right and 74 on the left. Linear regression analysis demonstrated a statistically significant probability value (p < 0.0001) comparing NIRS frontal oximetry and CT perfusion–obtained CBF values. Conclusions The authors demonstrated a linear correlation for frontal NIRS cerebral oxygenation measurements compared with regional CBF on CT perfusion imaging. Thus, frontal NIRS cerebral oxygenation measurement may serve as a useful, noninvasive, bedside intensive care unit monitoring tool to assess brain oxygenation in a direct manner.

Intracranial aneurysms in the pediatric population are relatively rare entities. Immunocompromised patients (often from HIV/AIDS or pharmacological immunosuppression) represent a significant fraction of children with cerebral aneurysms. One proposed mechanism of aneurysm formation in these patients is from direct infection of the affected arteries. In this study, the authors report on a case of a 14-year-old girl with common variable immunodeficiency with T-cell dysfunction and a CSF polymerase chain reaction test positive for varicella-zoster virus who underwent evaluation for carotid and basilar artery fusiform aneurysms.

Object The pathophysiology of myocardial dysfunction after subarachnoid hemorrhage (SAH) remains unclear. Using myocardial real-time perfusion contrast echocardiography (RTP-CE), the authors evaluated microvascular function in patients with acute SAH. Methods Over a 15-month period, 10 patients with acute SAH and evidence of cardiac dysfunction were prospectively enrolled. The authors performed RTP-CE within 48 hours of SAH diagnosis. Wall motion and myocardial perfusion were evaluated in 16 left ventricle segments. Qualitative and quantitative RTP-CE analyses were conducted to compare patients with and without regional wall motion abnormalities (RWMAs). Follow-up RTP-CE at a mean of 53.7 ± 43 days was undertaken in patients with baseline RWMAs. Results Ten patients with SAH and evidence of cardiac dysfunction were prospectively enrolled. There were 3 men and 7 women whose mean age was 63.5 ± 10.1 years. The authors documented evidence of RWMAs in 6 patients. Normal perfusion was demonstrated by RTP-CE in all patients at baseline and follow-up, despite the presence of RWMAs. Compared with patients presenting with normal wall motion, in patients with RWMAs there was a trend for higher quantitative RTP-CE parameters, suggesting hyperemia with mean myocardial blood flow velocity (β, s−1) of 1.08 ± 0.61 (95% CI 0–2.61) compared with 1.62 ± 0.64 (95% CI 0.94–2.29) and myocardial blood flow (A × β, dB/s) of 0.99 ± 0.41 (95% CI 0–2.0) versus 1.63 ± 0.86 (95% CI 0.72–2.53). Follow-up RTP-CE was feasible in 3 patients with RWMAs. Regional systolic function was restored in those who completed follow-up. Conclusions The authors found that RTP-CE readily evaluates microvascular function in patients with SAH. Wall motion and perfusion dissociation were observed. Quantitative RTP-CE showed a trend for microvascular hyperemia in patients with RWMAs, suggesting that post-SAH myocardial dysfunction could occur in the absence of microvascular dysfunction.