Mostly abstracts, as it costs to view the papers. However, much can still be gleaned in the writeups.
General info.:
http://brain.oxfordjournals.org/cgi/content/full/125/8/1887
http://www.neurology.org/cgi/content/abstract/41/7/1021
On rarity:
http://www.springerlink.com/content/y02548886n72386h/
http://www.ncbi.nlm.nih.gov/pubmed/16340924
On bronchial involvement:
http://content.karger.com/ProdukteDB/produkte.asp?Aktion=ShowFulltext&ArtikelNr=000095703&Ausgabe=232196&ProduktNr=223840