Learn More
Human cortical activity has been intensively examined at frequencies ranging from 0.5 Hz to several hundred Hz. Recent studies have, however, reported also infraslow fluctuations in neuronal population activity, magnitude of electroencephalographic oscillations, discrete sleep events, as well as in the occurrence of interictal events. Here we use direct(More)
We evaluated the rapid changes in regional scalp EEG synchronization in normal subjects with spatial and temporal resolution exceeding prior art 10-fold with a high spatial density array and the Hilbert transform. A curvilinear array of 64 electrodes 3 mm apart extending 18.9 cm across the scalp was used to record EEG at 200/sec. Analytic amplitude (AA) and(More)
OBJECTIVE Evaluate spectral scaling properties of scalp electroencephalogram (EEG) and electromyogram (EMG), optimal spacing of electrodes, and strategies for mitigating EMG. METHODS EEG was recorded referentially from 9 subjects with a 64 channel linear array (electrodes 3mm apart) placed parasagittally or transversely on forehead or occiput, at rest(More)
OBJECTIVE To transfer to the clinic for humans the technology and theory for high-resolution EEG analysis that have been developed in the laboratory with animals. METHODS EEGs were recorded at high spatial resolution from a 1 x 1 cm 8 x 8 electrode array on the right inferior temporal gyrus of a patient undergoing preoperative monitoring for epilepsy(More)
Effects of soft skull bone, cerebrospinal fluid (CSF) and gray matter on scalp potentials were examined with highly heterogeneous finite element models of an adult male subject. These models were constructed from segmented T1 weighted magnetic resonance images. Models had voxel resolutions of 1x1x3.2 mm with a total of about 1.5 million voxels. The scalp(More)
Long-term video electroencephalographic (EEG) recording is currently a routine procedure in the presurgical evaluation of localization-related epilepsies. Cortical epileptogenic zone is usually localized from ictal recordings with intracranial electrodes, causing a significant burden to patients and health care. Growing literature suggests that(More)
OBJECTIVES Vitamin D has immune-modulating effects and may protect against the development of systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). METHODS We identified incident cases of SLE and RA among 186 389 women followed from 1980 to 2002 in the Nurses' Health Study and Nurses' Health Study II cohorts. We excluded subjects where SLE or(More)
OBJECTIVE To study whether hemodynamic changes in human brain generate scalp-EEG responses. METHODS Direct current EEG (DC-EEG) was recorded from 12 subjects during 5 non-invasive manipulations that affect intracranial hemodynamics by different mechanisms: bilateral jugular vein compression (JVC), head-up tilt (HUT), head-down tilt (HDT), Valsalva(More)
PURPOSE To determine whether specific regions of cerebral cortex are activated at the onset and during the propagation of absence seizures. METHODS Twenty-five absence seizures were recorded in five subjects (all women; age 19-58 years) with primary generalized epilepsy. To improve spatial resolution, all studies were performed with dense-array,(More)
BACKGROUND This study tested the idea that very slow EEG responses (direct current [DC] potential shifts) could be detected noninvasively during temporal lobe (TL) seizures, and that these shifts give lateralizing information consistent with that obtained by other methods. METHODS Seven patients with TL epilepsy (TLE) were recorded with scalp DC-EEG(More)