Itching can certainly be from peripheral neuropathy but I have not heard of it affecting the scalp, just the areas where other symptoms are, like feet, legs, hands etc. It should respond to gabapentin or Lyrica. Another common cause of scalp itch is seborrheic dermatitis and itch may be the only symptom. It responds well to Neutrogena T-sal shampoo and may be worth a try. Put the shampoo on scalp first and leave it while you shower. Rinse hair last, so the anti inflammatory salicylate has longer contact with skin. Itching is common in autoimmune disorders, allergies and certain blood disorders so that might be considered and tested if itching is all over. Rx betamethasone solution is a potent topical steroid that is watery and can be applied to scalp. Your dr may be willing to let you try that, particularly if you have a dermatologist.