What causes sensitivity in the scalp?
Stress or hair wash routine
I understand your concern. First of all, let me reassure you that sensitive scalp has nothing to do with a brain problem. This is a very common condition and is either due to increased stress and anxiety or not washing your hair frequently, which leads to dead skin and oil build up around hair follicles causing inflammation of the scalp. Hence the sensitivity and pain upon touching your hair.
Another reason maybe your hair style. Keeping your hair in a ponytail or braids or a bun may also irritate the scalp.
I recommend you wash your hair every other day with a mild shampoo and massage your scalp with your finger tips while in the shower. If stress is the reason, frequent showers and relaxation techniques can greatly help.
I hope this answers your question. Let me know if I you have further questions.