OBJECTIVE Accurate ear-canal acoustic measurements, such as wideband acoustic admittance, absorbance, and otoacoustic emissions, require that the measurement probe be tightly sealed in the ear canal. Air leaks can compromise the validity of the measurements, interfere with calibrations, and increase variability. There are no established procedures for determining the presence of air leaks or cr...

Lumbar puncture (LP) still has an important role to play in the diagnosis of subarachnoid hemorrhage. Although computed tomography (CT) scanning has replaced LP as the investigation of first choice, within 24 h of ictus 5% of cases will show no evidence of hemorrhage on CT scanning; this percentage is as high as 50% by 1 week, 30% after 2 weeks, and 0% after 3 weeks (1). By definition, xanthoch...