Can brain training rewire diabetic nerve pain?

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion criteria * Age ≥18 and ≤82 years * Diagnosed with 1) type 1 diabetes (for at least 5 years) or 2) type 2 diabetes * Confirmed diagnosis of at least "Probable Diabetic Polyneuropathy" as defined by Toronto Consensus Criteria (Presence of a combination of symptoms and signs of neuropathy including any two or more of the following: neuropathic symptoms, decreased distal sensation, or unequivocally decreased or absent ankle reflexes), and at least one of the following: * TCNS \> 5 * Abnormal DPNCheck results (amplitude \< 4µV and/or conduction velocity \< 40 m/s) * Abnormal NCS (Nerve Conduction Study) * Confirmed diagnosis of at least "Probable Neuropathic Pain" as defined by NeuPSIG guidelines (Pain distribution which makes neuropathic pain neuroanatomically plausible and history suggests relevant disease (e.g., symmetric pain in the feet/lower extremities and history of diabetes), and at least one of the following: * Negative or positive sensory signs, confined to innervation territory of the lesioned nervous structure (abnormal findings in at least one of: pinprick, temperature sensation, light touch (monofilament), vibration sense (biothesiometry or 128Hz tuning fork, position sense). * Abnormal DPNCheck results (amplitude \< 4µV and/or conduction velocity \< 40 m/s) * Abnormal NCS (Nerve Conduction Study) * Eligible patients with painful DPN must have a pain intensity of at least 4 on an 11-point numerical rating scale (NRS, 0-10) for at least 3 months on at least semi-daily basis and no severe pain other than pain due to neuropathy (the pain intensity will be based on the pain the patients experience while on current pain treatment, if any). * Stable pain medication for \> 1 month prior to inclusion. Exclusion criteria * Concomitant neurological (neurodegenerative disorders, migraine, epilepsy, stroke, tumor) or clinically significant psychiatric illness * Neuropathy or neuropathic pain due to other causes than diabetes (vitamin B12 deficiency, prior treatment with neurotoxic chemotherapy, chronic alcohol abuse, spinal stenosis, etc.) * Change in current pain treatment during treatment (paracetamol is allowed as rescue medicine) * Prior or current excessive alcohol use (\>14 or \>21 units/week for women and men, respectively) or illegal substance abuse * Positive urine hCG test result indicating pregnancy * Morphine use \>20mg/day * Blindness or severely impaired vision * The investigator finds the patient unfit for the study (e.g. due to use of alcohol or drugs, mental incapacity, unwillingness, or language barrier precluding adequate understanding or cooperation or presence of any condition that in the investigators' opinion may lead to poor adherence to study protocol).