Fascinating

"Fearless" Patients Terrified By Panic Experiment

A new study describes how "fearless" patients with damage to the brain's amygdala or "fear centre" experienced terrifying panic in a suffocation experiment, suggesting other brain circuits that do not involve the amygdala can also produce a fear response in reaction to potential threats.
Previous studies clearly show that the amygdala plays an important role in processing external events, threats from the environment, and in the social aspect of emotion, such as recognizing the facial expressions of others. But Feinstein and colleagues propose their findings reveal the amydgala may not be the only circuit for the fear response, or for all fear responses. There may be another circuit for processing events that arise within the body, they say.

 I believe this.   I think the panic caused by low blood sugar is different than from external events too.  I think it may make us hypersensitive to environmental stimuli.