Well, while could be some neurological thing might show up on your MRI that shows a reason for your pins and needles sensation in your lower extremities and left hand, plus your left calf fatigue, like could be you had a little bleed in the brain or there might be a benign growth, there is also a very good possibility that this has more to do with how you're breathing. Since you're all stopped up in your nose, the sort of hyperventilating or lack of deep breathing that may go on from that, especially when you do sports, can cause those pins and needles and strange sensations. Allergy is often responsible, especially to MSG, which is a food enhancer used in Chinese food, soy sauce, that sort of thing, altho it's put in a lot of foods. Still, I think it's good you went to a neuro, maybe go back to see him on a yearly basis, in case things get a lot worse, that way you'll have a good doc who knows you. And of course pay attention to a possible MSG allergy, possibly visit an allergist.
I might add that whenever my nose gets all stopped up and I cannot breathe very well, I'll get a PLAIN saline spray with nothing else in it, at the drugstore, and squirt it in my nose a few times a day, and it helps drain it better so I can breathe better. Work on deep breathing, too, once a day, perhaps, just get in a relaxed state of mind and sit on the floor and look at an object you like, and breathe in really deeply, blow it all out, then breathe normal for a few times, then repeat ten times. Think of nothing else but that object and your breathing. Then if you get in a situation where you cannot catch your breath, just think of that object and get into deep breathing, just a few times ought to bring you around. Keep us posted.
Thank you for your question. Although without being able to examine you I can not offer you the specific advice on diagnosis and treatment that you need, but I would try to provide you some relevant information about your health concern.
If your all the reports came back absolutely normal, then this numbness or tingling would have occurred when you are depressed or stressed due to general anxiety disorder. A doctor may suggest counseling or psychotherapy, physiotherapy, treating related stress and avoidance of triggering factors by doing meditations/yoga that can be helpful in recovering from the condition. Additionally, it will be helpful if you keep the symptoms occurrence log where you can record and specifics the sensations, including how long they lasted, any triggering factors that you may have noticed. This will help your doctor to determine the nature of the neurological factors that causing it, therefore what kind of treatment need to be started. Hope this information proves helpful to you. Take Care & Regards!!!