Then, as now, there was an uneasy sense of American decline on the world stage.

FORBES: President Obama Is The Second FDR, Not The Second Carter

Questions remain about using deep-brain stimulation to treat dementia, including whether it would work for Alzheimer's patients and at what stage of decline, whether it is safe and how long the effect will last, said Dr. Salloway.

WSJ: Memory Gets Jolt in Brain Research

Typically an early February high sets the stage for a decline that lasts for most of the month.

FORBES: Are You Ready for a February Surprise?