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Background. The N2 and P3 components of auditory event-related potentials (ERPs) and single-photon emission computed tomographic (SPECT) images are separate independent biological markers of cerebral function and are abnormal in Alzheimer's disease (AD). The relationship between ERP N2 and P3 latencies and regional cerebral perfusion abnormalities in AD is unknown. Methods. ERP and SPECT data were obtained one week apart in 18 patients with 'probable' AD of mild or moderate severity, and 12 healthy age-matched elderly controls. Average premotor frontal, anterior temporal, inferior parietal, and occipital cortical/cerebellar perfusion ratios were calculated from the SPECT data and correlations with ERP N2 and P3 latencies derived for AD and control groups separately. Results. ERP N2 latency was correlated significantly with the average frontal perfusion ratio (r = -.59; p < .009), but correlations with average temporal, parietal, and occipital ratios were nonsignificant in the AD group. Similarly, ERP P3 latency was correlated significantly with the average frontal perfusion ratio (r = -.65; p < .004); but not with the other perfusion ratios in the AD group. In the control group, a partial! correlation between the average frontal perfusion ratio and the ERP N2 latency was noted (r = -.52; p < .09), but no other ERP/SPECT correlations approached statistical significance. Conclusion. ERP N2 and P3 latency delay in AD is a function of differential frontal lobe hypoperfusion.

Introduction Tetanus has been described as the 'inexcusable disease' as it can be prevented by the use of a highly efficient vaccine [1]. The introduction of routine immunization in childhood [...]

Arterial closing pressure (ACP) helps detect pseudohypertension more accurately than diastolic measurements. In the absence of pseudohypertension, there is an automatic closure of the bronchial artery, while the pressure applied by a water cuff is essential to facilitate artery closure in cases with pseudohypertension. The extent of pseudohypertension exhibits a relationship with ACP.

Background. Ocular microtremor (OMT) is a high-frequency tremor of the eyes. It is present in all individuals and is related to brainstem activity. The OMT signal appears as an irregular oscillatory movement with intermittent burst-like components. The clinical interest in OMT has centered on its use in the assessment of the comatose patient, with broad agreement among authors of its prognostic value. The purpose of this study was to examine the changes in OMT activity related to aging. Methods. OMT was recorded from 72 normal healthy subjects using the piezoelectric strain gauge technique. The subjects ranged in age from 21 to 88 years (54.22 [+ or -] 20.43 years, mean [+ or -] SD). Results. Our results show that the overall frequency and frequency content of the bursts falls with age (p [is less than] .002 and p [is less than] .001, respectively). There is a highly significant drop in all three frequency parameters of OMT (p [is less than] .0001) in subjects older than 60 years of age. Conclusions. These results suggest that different values of normality should operate for subjects over 60 years of age when considering the clinical application of OMT.

The eyes of all normal subjects undergo a continuous, low-amplitude, high-frequency tremor called ocular microtremor (OMT). A number of potential clinical applications of OMT have been identified, including the prediction of outcome in coma. To date, OMT has been investigated primarily with an eye-contacting piezoelectric probe. We describe a laser-based, noncontacting, interferometric technique for the measurement of OMT. The technique employs an in-plane-sensitive, phase-modulating speckle interferometer to detect the movement of the sclera, or white of the eye. [C] 2001 Optical Society of America OCIS codes: 120.3930, 120.3181, 170.3890, 170.4460, 170.4580.