Shahi Syed is right in the sense that the plant Cannabis (Hashish, Charas, Bhang, Marijuana) as a decoction with milk and sugar has been consumed by mystics since times unknown. It makes them feel as if flying to strange worlds, even above the skies. Of course, it is quite addictive due to the euphoria it provides.
Micrcephalics (Pinheads) is a genetic disorder found everywhere in the world. The incidence is about one child born with microcephaly among 1,000 normal children. The condition is not associated with Shah Daulah shrine at all except that some parents leave these disabled children there as a shelter. Everything else is myth spread by ignorance and superstition.