Role of magnetic resonance imaging, cerebrospinal fluid, and electroencephalogram in diagnosis of sporadic Creutzfeldt-Jakob disease.

Sporadic Creutzfeldt-Jakob disease (sCJD) is a rapidly progressive dementia (RPD) that can be difficult to identify antemortem, with definitive diagnosis requiring tissue confirmation. We describe the clinical, magnetic resonance imaging (MRI), cerebrospinal fluid (CSF), and electroencephalogram (EEG) measures of a small cohort of 30 patients evaluated for RPD. Clinical and diagnostic measures were cross-sectionally obtained from 17 sCJD patients (15 definite, two probable), 13 non-prion rapidly progressive dementia patients (npRPD), and 18 unimpaired controls.

Phase resetting properties of cardiac pacemaker cells.

Aggregates of heart cells from chicken embryos beat spontaneously. We used intracellular microelectrodes to record the periodic behavior of the membrane potential that triggers the contractions. Every 5-12 beats, a short current pulse was applied at various points in the cycle to study the phase-dependent resetting of the rhythm.