What Causes Involuntary Forehead Twitching Between The Eye Brows?

For many years I have had a problrm with involuntary forehead twitching right between my eye brows. It comes and goes, some days it doesn t happen at all and other days it happens all the time. I have seen a neurologist and have had a CT scan, still no answers...The neurologist just wanted to inject me with Botox, which was semi helpful but thats not the route that I want to go with this. I want to find the cause so I can fix it. I avoidedcaffeine, do not drink alcohol, and do not smoke or use other stimulants and I am otherwise a very healthy person. There are no other muscle spasms anywhere else on my body...What do you think?