@gigiraj Twitching and spontaneous contraction can occur because of irritation anywhere along a nerve path from the spinal cord to the fingers and in all the places where nerves travel between muscles, tendon and bones. If this is happening in your dominant hand, pay attention to what increases or decreases symptoms. It may be something like the use of your fingers in texting combined with a forward bent neck position. That's a guess on my part as I don't know your habits, but texting is causing issues in younger people and all of that puts extra uneven pressure on the spine and discs. Over time, poor posture can cause spine problems and degeneration. Some of that is going to happen just from aging, so correcting posture when you are young is a great step toward future health. If I sound like a person who worries about spine health, well that's true. I am a spine surgery patient and learned through my own experience. I had an injury years earlier that with aging caused degeneration of a disc in my neck. I also have thoracic outlet syndrome which causes nerve entrapment in my shoulder and neck and is posture related and partly because of my physical build. A forward position of the neck and shoulders causes more pressure on the nerves. I can have twitching muscles if it gets bad. I also have carpal tunnel, and with all of this and multiple points of nerve compression, it can be complex to figure it out. Sometimes, it is just tight muscles and fascia that pull things out of alignment and put pressure on nerves. I did have a problem with my thumb and index finger that was caused by a spinal injection because of the pressure of the injected fluid. I already had central spinal canal stenosis at the time, and the injection was near the nerve root that innervates my thumb and forefinger. Your neurologist should try to pinpoint if there is a specific location of nerve entrapment or dysfunction. You might want to make a diagram to keep track of the issues and if it changes over time, and what type of symptom you have such as twitching, pain, tingling, numbness, etc. I actually had twitching in several places in my body caused by spinal cord compression because those were the source of the nerves that went to the twitching muscles. I have had spine surgery to decompress the spinal cord which resolved the problem.

It may be a physical issue rather than a disease. Physical therapy can help. There are are PTs who specialize in hand therapy. It helps me a lot, and my therapist also does a lot of myofascial release. We have a lot of information about that and how it helps lots of physical issues in the discussion that you can find here.
https://connect.mayoclinic.org/discussion/myofascial-release-therapy-mfr-for-treating-compression-and-pain/