Bob, a 38 year old male, has been experiencing severe intermittent headaches for about 10 years. When they occur, he experiences intense burning pain on one side of his head, tearing in his eye, congestion and a runny nose. These headaches generally occur several times a day and last approximately one hour. The headaches are episodic; Bob can be headache free for several months but then experience an attack.

1. Based on the case scenario, provide a diagnosis for Bob. Provide the pathophysiology for this type of headache and discuss current treatment options.