I’ve had buzzing in my feet/calves for a few months. I know it’s definitely not MS as I had a brain MRI (prior to the buzzing) earlier this year for another issue and in the results they happened to remark (in medical jargon) that there was no MS. Hope this reassures you that buzzing sensations can and do happen without a serious underlying cause. I notice mine particularly when I’m led in bed at night, especially if I am more tired than usual. No idea what causes it but I try not to worry about it as it’s probably just a combination of tiredness, anxiety of trapped nerves.