The primary objective of this study is to determine if a sphenopalatine ganglion (SPG) block, performed through intranasal atomization of 4% lidocaine, is able to prevent cold induced cephalgia ("Brain Freeze"). Secondary objectives will be to determine the degree of decreased pain/duration of brain freeze after sphenopalatine ganglion block

This study will be performed in two phases. The first phase will include a pre-medicated phase where the subjects will be required to rapidly drink up to ½ of a 32 fluid oz icecold slushy to induce a brain freeze. The flavor will be chosen by the participants. The time to onset, intensity, location, and duration of the headache will be recorded. The second phase will commence when the subjects have returned to their normal pain free state, a minimum of 10 minutes has passed since the resolution of the first cold headache, and they feel ready to move to the next phase. The time from complete resolution of the brain freeze to the start of the second phase will be recorded. Any subject that wishes to drop out from the study at this time is free to do so. They may keep their drink and finish it at a more leisurely pace should they choose.

Then the subjects will receive either 1 mL of 4% lidocaine (0.5mL in each nostril) administered by intranasal atomization or 0.9% normal saline administered by intranasal atomization. The normal saline placebo will be mixed with an edible bittering agent added to blind the participant from recognizing the taste of the lidocaine containing solution.

Only participants that experienced a brain freeze in the first phase will be able to move onto the second phase. Each participant will then rapidly drink up to ½ of a 32 fluid oz ice-cold slushy to induce a brain freeze. The time to onset, intensity, location, and duration of the headache will be recorded.

All pain scores will be recorded using a visual analog scale from 0-100 where 0 is no pain and 100 is the worst pain imaginable. We will also record any side effects that the subjects may experience during or shortly after the procedure.

Inclusion Criteria:

• Wright State University Emergency Medicine (EM) resident physicians and Wright State Boonshoft School of Medicine medical students
• Over the age of 18 years
• Has gotten at least one brain freeze in their life

Exclusion Criteria:

• Individuals who have never gotten a brain freeze
• Anyone who has had any sort of prior trauma to their oro- or nasopharynx or surgery on their oro- or nasopharynx, not to include dental surgery.
• Pregnant patients
• History of allergy to local anesthetic

All besides PI