<s>[INST] I was minutes into ascent of airliner..suddenly my left side of my mouth became numb, quickly followed by the entire left side of my face. Once numbness had taken over the left side of my face..including teeth and gums..intense pain followed. The pain so debilitating I could barely keep my dignity on the flight.The numbness and pain lasted until the final minutes of the 2 hour flight. What could cause this scary symptoms? [/INST] Hi, Thank you for posting your query. Your symptoms are suggestive of a problem in the trigeminal nerve area, which starts in the brain stem and supplies the face. It may be useful to do an MRI scan of the brain, to identify the underlying reason. Mainly, we need to exclude any ischemic lesion (lack of blood flow to that area). Please get back if you require any additional information. Best wishes, Chat Doctor. Ly/ </s>