I'm reading a fiction, A Thousand Splendid Suns, by Khaled Hosseini.  He also authored The Kite Runner which many may be more familiar with.  Towards the end of the book there is a paragraph that seems to describe one of the characters having a cluster.  I thought it was interesting since I've never heard or read anything about CH unless I went looking for it.  To stumble across it in a book, and since my husband is the the middle of a cycle - and he hasn't cycled for 4 years now - seems ironic.  Anyway, here's the text from the book: (as info, it's about two women in Afghanistan and the horrors they go through - Tariq is the husband of one of the women)

"Tariq has headaches now.  Some nights, Laila awakens and finds him on the edge of their bed, rocking, his undershirt pulled over his head.  The headaches began in Nasir Bagh, he says, then worsened in prison.  Sometimes they make him vomit, blind him in one eye.  He says it feels like a butcher's knife burrowing in one temple, twisting slowly through his brain, then poking out the other side. " ...  "some nights all Tariq can do is hold his head and moan, his eyes bloodshot, his nose dripping."

Interesting!  Thanks for pointing it out to us Kay.