Transcutaneous Electrical Nerve Stimulation for Chronic Postherpetic Neuralgia
By Malcolm R. Ing, MD
“Treatment of postherpetic neuralgia (PHN) remains a challenging problem for clinicians. Herpes zoster is a relatively common disease with an incidence of 5 per 1000 patients per year. Involvement of the ophthalmic branch of the trigeminal nerve occurs in about 20% of cases. The typical clinical presentation of ophthalmic zoster is blisters and inflammation of the skin supplied by the first division of the trigeminal nerve. If the pain and inflammation remains in the skin after one month with persisting neuropathic pain, it is termed chronic PHN.
The risk of developing PHN is highest with increasing age and presents a major public health issue. Many treatment modalities have been considered with limited success. Side effects from medical treatment include nausea, sedation, postural hypotension, dizziness, and somnolence. Constipation and sedation from opioids make these drugs poorly tolerated in the elderly.
Biofeedback is a well accepted therapeutic treatment option. Electronic devices are often utilized in biofeedback therapy. Modern modification of these self-controlled electronic neuroadaptive regulation (SCENAR) devices, such as the Tennant BioModulator® (TBM), have been granted a Food and Drug Administration class II designation to help with CPN.