I can understand how distressing this is when it disturbs your sleep. Burning feet with a normal nerve conduction study is usually a small fibre neuropathy, which the routine NCS cannot pick up, so a normal report does not mean nothing is wrong. Common causes worth excluding again are prediabetes (please get fasting
sugar, post meal sugar and
HbA1c, not just fasting),
thyroid function,
kidney function, HbA1c along with
vitamin B6 excess from supplements, alcohol intake, and rarely coeliac disease. Restless legs, plantar fasciitis, tarsal tunnel compression and simple footwear related pressure also give evening burning. About your treatment, Aton 300 mg is pregabalin, and for small fibre pain the dose usually needs slow upward titration under your neurologist's guidance rather than being abandoned as ineffective, so please go back to him and discuss increasing it or adding duloxetine or nortriptyline instead of stopping on your own. Meanwhile keep the feet cool, avoid hot water soaks, wear soft wide cushioned footwear, do not walk barefoot on hot floors, avoid alcohol, and stop any high dose vitamin B6 supplement. Please seek prompt review if you develop weakness of the feet, foot drop, ulcers, colour change of the toes or bladder symptoms. You are welcome to consult me here with all your reports (fee Rs 500) or at Synergy Multispeciality Hospital, Miraj.