Role of Lead in the Central Nervous System: Effect on Electroencephlography, Evoked Potentials, Electroretinography, and Nerve Conduction.

The toxic effects of lead on the brain are well known, but its effects on EEG and evoked potentials (EPs) are not generally known in the neurodiagnostic community. Despite public health efforts, lead is still widely present at low levels in the environment. Even at low concentrations, lead is known to cause biochemical and physiological dysfunction.

Single-unit responses selective for whole faces in the human amygdala.

The human amygdala is critical for social cognition from faces, as borne out by impairments in recognizing facial emotion following amygdala lesions [1] and differential activation of the amygdala by faces [2-5]. Single-unit recordings in the primate amygdala have documented responses selective for faces, their identity, or emotional expression [6, 7], yet how the amygdala represents face information remains unknown. Does it encode specific features of faces that are particularly critical for recognizing emotions (such as the eyes), or does it encode the whole face, a level of representation that might be the proximal substrate for subsequent social cognition? We investigated this question by recording from over 200 single neurons in the amygdalae of seven neurosurgical patients with implanted depth electrodes [8].

Influence of magnetic source imaging for planning intracranial EEG in epilepsy.

Background: Magnetic source imaging (MSI) is used routinely in epilepsy presurgical evaluation and in mapping eloquent cortex for surgery. Despite increasing use, the diagnostic yield of MSI is uncertain, with reports varying from 5% to 35%. To add benefit, a diagnostic technique should influence decisions made from other tests, and that influence should yield better outcomes.