Animal model studies indicate light-absorption changes of the exposed animal brain in response to visual stimulation. Here we report observations of red-light absorbancy changes, attributable to repetitive blood concentration changes in response to stimulation in the human brain frontal region by a cognitive process. These responses are observed as low-frequency recurrence of changes by Fourier transform analysis and are attributed to blood concentration change stimulated by the increased metabolic rate of brain tissue in cognitive function. A simple, portable dual wavelength spectrophotometer was attached noninvasively to the human forehead to measure the low frequency and power spectra of fluctuations of absorbancies attributed to variations of brain blood concentration in the frontal region. The responses are associated with brain activity in responses to problem solving of analogies presented visually that require an associative function in the frontal region. The method of subtraction of test -rest Fourier transforms minimizes the arterial pulse frequency contributions and identifies specific frequencies-for example, 0.8, 1.6, 1.8 Hz in 24 of 28 tests of nine individuals (85%). Tests in which no increased brain activity was elicited (rest -rest) showed small differences. It is concluded that low-frequency recurrences of brain activity linked to blood concentration increases can be detected in human subjects with an optical device of potentiality for simplified tests of cognitive function in the 0-to 3-Hz region and with modifications for wider band recordings in localized tissue volumes by timeresolved spectroscopy.In this study a simple optical method (1) was used to cause photon migration from the surface of the head through the skin, skull, and underlying brain tissues to a detector 4 cm distant, also on the surface of the head. Absorption and/or scattering changes of light along the pathway of photon migration are sensitively detected.The linkage between cerebral activity, oxidative metabolism, and oxygen delivery is demonstrated in animal models (2). The coupling between brain activity, metabolism, and blood flow is demonstrated in human subjects by positronemission tomography (PET) scanning (3). Blood concentration increases are linked to optical measures of visual responses in the exposed primate brain (4); 1H NMR shows localized blood flow changes on photic stimulation (5).This study is methodologically similar to the optical spectroscopy of the exposed brain in animals (4). In this case, transcranial signals are obtained and human studies are possible by a simple dual wavelength spectrophotometer used to study the frontal region of the forehead and to measure changes of light absorption related to cerebral function (L.L., unpublished data). The instrument is responsive to changes of both blood concentration and deoxygenation/oxygenation changes that are associated with activated brain function (6) as measured in the frequency domain as recurrences in the 0.1-to 3-Hz region and bridges the g...

For GSD-Ia, hyperuricemia and pyelonephritis should be treated to prevent nephrocalcinosis and additional renal damage. For GSD-Ib, granulocyte-colony-stimulating factor may prevent bacterial infections. For GSD-III, more data are required to determine whether the myopathy and cardiomyopathy can be prevented. Most of the patients with GSD-I and GSD-III had 12 or more years of education and were either currently in school or employed.

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Despite the perception that diabetes management was more difficult in college, metabolic control was maintained during college, possibly due to a more intensive treatment approach.