My husband suffered Rocky Mountain Spotted fever about three years ago. He seemed to have a recurrence and was treated for ten days with doxycycline. He finished the prescription yesterday. For the past several weeks he has been experiencing severe headaches with blurred vision, numbness in left arm, etc. He has always had these headaches, but usually weeks or months apart. Now they are daily to every other day. He has been tested over the years for the cause (before the Rocky Mountain Spotted Fever) with no explanation other that migraine. Could the more frequent headaches be the result of having had such fever?