title: Transcranial direct current stimulation (tDCS) relieved itching in a patient with chronic neuropathic pain.
abstract: Itching is often called the second modality of nociception besides pain, and affects many chronic pain patients.
  
  
  OBJECTIVE
  This case report presents a first note on beneficial effects of transcranial direct current stimulation (tDCS) on itching associated with chronic neuropathic pain in a patient diagnosed with syringomyelia.
  
  
  METHODS
  tDCS is a novel noninvasive neuromodulatory method with promising therapeutic potential in pain and symptom management. The primary mechanism of tDCS is subthreshold modulation of the neuronal resting membrane potential that induces a polarity-dependent modification of N-Methyl-D-aspartate receptor function that plays a role in neuroplasticity. The patient, a 46-year-old white male diagnosed with syringomyelia 2 decades ago, continuously reported weakness in the arms and dyesthesias including pain and itch that fluctuated in severity. Pharmacological treatment with baclofen, duloxetine, and bupropion was partially helpful; however, did not prevent flares of pain and other dysesthesias, including itch. The patient underwent 3 tDCS treatment courses consisting of 20 minutes of tDCS on 5 consecutive days at each course over 13 months.
  
  
  RESULTS
  Although there was no change in pain intensity or quality during or after tDCS, the treatment resulted in a reduction in itch to a mild, tolerable intensity that persisted for 3 to 4 months after each course, before returning to the pretreatment level. The patient has agreed to a plan of care that will incorporate neurostimulation every 4 to 6 months, as long as its effectiveness continues.
  
  
  CONCLUSIONS
  This case provides a rationale for future studies of neuromodulatory treatments for itch, and indicates a potential clinical use of neuromodulation in patients with unrelieved itching.
authors: Institute for Non-Invasive Brain Stimulation, Department of Pain Medicine and Palliative Care, Beth Israel Medical Center, New York, NY, USA. HKnotkov@chpnet.org
authors: Helena
authors: H
authors: Knotkova
authors: Russell K
authors: RK
authors: Portenoy
authors: Ricardo A
authors: RA
authors: Cruciani
mesh_terms: D059350:Chronic Pain / Q000150:complications* / Q000175:diagnosis / Q000517:prevention & control*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009437:Neuralgia / Q000150:complications* / Q000175:diagnosis / Q000517:prevention & control*; D010147:Pain Measurement; D011537:Pruritus / Q000175:diagnosis / Q000209:etiology* / Q000517:prevention & control*; D050781:Transcranial Magnetic Stimulation / Q000379:methods*; D016896:Treatment Outcome