Journal of neuroimaging : official journal of the American Society of Neuroimaging
-
The authors report a patient who presented with unexplained confusion. She was 15 weeks pregnant and had been having recurrent vomiting for several weeks. This was felt to possibly represent hyperemesis gravidarum, but she had several other possible contributing factors. ⋯ However, her follow-up MRI brain scan revealed typical findings of central pontine myelinolysis, which correlated with hyperreflexia and positive Babinski reflexes. This patient illustrates the constellation of signs and symptoms that can be seen with a demyelinating lesion of the pons. In addition, our case illustrates how this MRI scan finding can be quite nonspecific but may help to explain the clinical findings.
-
Cerebral vasoreactivity can be studied with transcranial Doppler (TCD) by monitoring CO2-induced middle cerebral artery (MCA) velocity changes. Expected MCA mean velocity (Vm) changes due to changes in end-expiratory CO2 (EE-CO2) are established, but reactivity of common carotid artery (CCA) volume flow rate (VFR) has not been extensively reported. The authors assess the relationship between MCA Vm, CCA VFR, and EE-CO2. ⋯ MCA Vm increased 0.3 cm/s for each ml/min increase in CCA VFR. In normal individuals, there is a direct correlation between MCA Vm, CCA VFR, and EE-CO2. Measurement of CCA VFR changes during CO2 inhalation may be an alternative method to estimate cerebral vasoreactivity when the MCA velocity cannot be obtained because of inadequate acoustic temporal windows.
-
The Stroke Prevention in Sickle Cell Disease (STOP) trial used transcranial Doppler (TCD) to screen children with sickle cell disease with no history of stroke. Children (who consented) who had time-averaged mean of the maximum (TAMM) velocities in the middle cerebral artery and/or distal internal carotid artery were randomized to transfusion or standard. ⋯ For the STOP TCD data to be applied appropriately, it is necessary for users of TCD to understand how the STOP TCD examinations were performed, how the TCD velocities were measured, and which velocities were used. This article will review the STOP TCD scanning protocol and the reading protocol and review the TAMM velocity and how it differs from other velocity measurements.