Alternating and Direct Current Stimulation for Neuropathic Eye Pain

Alternating and Direct Current Stimulation for the Treatment of Chronic Neuropathic Eye Pain and Cerebral Symptoms: a Pilot Study

The goal of this clinical intervention is to test if two forms of transcranial current stimulation, transcranial direct current stimulation (tDCS) or transcranial alternating current stimulation (tACS) can alleviate neuropathic eye pain in a sample of 20 patients.

The main aims are:

• Test if tDCS/tACS can alleviate neuropathic eye pain and/or other cerebral symptoms: brain fatigue, migraine, light sensitivity, etc.
• Test if one stimulation method is superior to the other Patients will be treated for a total of fifteen 30-minute stimulation sessions, three times a day over a five-day period, each stimulation separated by approximately 4 hours, with either active tACS or tDCS over the scalp corresponding to primary sensory and motor areas.

The patients will have questionnaires to monitor subjective experiences and pupillometry before and after treatment to monitor experimental outcomes.

Brief Summary sufficient

Inclusion Criteria:

• persistent eye pain for at least 6 months
• average eye pain intensity of 4 or more on a 0-10 numerical rating scale
• naive to transcranial stimulation
• eye pain having neuropathic-like characteristics

Exclusion Criteria:

• contraindication to transcranial stimulation (i.e., pacemaker, cardioverter defibrillator, neuro-stimulation (brain or spinal cord), bone growth stimulations, indwelling blood pressure monitors, epilepsy, pregnancy)
• presence of ocular diseases that are the likely cause of pain (i.e., corneal and conjunctival scarring, corneal edema, uveitis, iris transillumination defects, etc.)
• current participation in another study with an investigational drug or device within one month prior to screening