What DHE migraine protocol works best for acute treatment both in terms of dosage and timeframe?

Dihydroergotamine (DHE) is a non-specific ergot that acts on the serotonergic, dopaminergic, and adrenergic pathways. It is used as an acute migraine treatment that can be given parenterally or nasally. Oral does exist, but is not available in the USA. It may be used acutely as a rescue treatment du...