None listed
Conditions
Brief summary
Tinnitus is a significant and growing health challenge globally, affecting individuals, their whanau, the wider community, and the healthcare system. Tinnitus, defined as the phantom perception of sound, is estimated to affect 6% of New Zealand’s total population aged 14 and over, with prevalence increasing alongside age. For 2-3% of individuals in the population, tinnitus leads to significant impairments in quality of life. Psychological comorbidities associated with tinnitus drive much of the morbidity, and result in significant loss of health and productivity. Commonly reported symptoms include cognitive dysfunction, annoyance, insomnia, anxiety, and depression. Additionally, tinnitus management is a significant financial burden: in New Zealand, the approximate annual costs of tinnitus are estimated to be $7.5 billion. This makes tinnitus an attractive target for improving health related quality of life. Bimodal approaches may offer significant value in treating tinnitus, by coupling plasticity generation to a means of directing the brain towards a more normal state. Hypothesis: That low dose Ketamine, through effects on brain plasticity, may be able to catalyse transcranial electrical stimulation, to reduce tinnitus loudness, and/or distress. The aim of the proposed study is to explore the effect over short term follow-up of ketamine and transcranial stimulation on tinnitus loudness and distress, in participants suffering from tinnitus, in a controlled trial.
Interventions
Brief Name: Ketamine and High Definition, Trancranial Infraslow Pink Noise Stimulation (HD-tIPNS)
The intervention arm will receive a low dose of subcutaneous ketamine (0.5mg/kg) as a bolus, from a clinician experienced in administration. This will be followed by HD-tIPNS administered for a single session of 30 minutes duration, beginning ~25 minutes after ketamine delivery, by a researcher experienced in administering neuromodulation techniques. A battery-driven wireless 32 channel transcrania
Brief Name: Ketamine and High Definition, Trancranial Infraslow Pink Noise Stimulation (HD-tIPNS) The intervention arm will receive a low dose of subcutaneous ketamine (0.5mg/kg) as a bolus, from a clinician experienced in administration. This will be followed by HD-tIPNS administered for a single session of 30 minutes duration, beginning ~25 minutes after ketamine delivery, by a researcher experienced in administering neuromodulation techniques. A battery-driven wireless 32 channel transcranial current stimulator (Starstim32 TCS®, Neuroelectrics, Spain, http://www.neuroelectrics.com) will be used to deliver stimulation while the participants are comfortably and quietly seated. Simulation is delivered by AgCl electrodes placed in the international 10-20 arrangement, secured in a neoprene cap (see Neuroelectrics website for headset image). For the active treatment group, the stimulation will be delivered at a current strength of maximum of 2mA for 30min, with 60s ramp up and ramp down at the beginning and end of each stimulation session, with continuous stimulation in between. For sham stimulation, to create an identical skin sensation to the active stimulation, the current will be applied for a 60s ramp up (0-2mA) and 60s ramp down (2-0mA) at the beginning and the end of each stimulation session, without any current for the remainder of the stimulation period. This Intervention will be delivered twice, spaced 10 days apart. Intervention duration will be a total of 2 hours in length to allow for safety monitoring. After a 20 day washout, both groups will transition to the intervention, delivered twice again, 10 days apart. The delayed start occurs as follows: Participants can be allocated to start with Ketamine + Active Stimulation or Ketamine + Sham Stimulation. Both the sham stimulation and the active stimulation groups will receive active stimulation after the 20 day washout (the Ketamine + Sham stimulation is the active control). Therefore the Ketamine + Sham stimulation (Active control) receives a delay to the start of active intervention. Participants will undergo treatment at the Department of Psychological medicine laboratory at the Dunedin School of Medicine, University of Otago.
Sponsors
Dirk De Ridder
Study design
Allocation
Randomised controlled trial
Intervention model
Other
Primary purpose
Treatment
Masking
Blinded (masking used) (Subject, Outcomes Assessor)
Eligibility
Sex/Gender
All
Age
18 Years to 70 Years
Healthy volunteers
No
Inclusion criteria
Adults aged between 18-70 years with constant subjective tinnitus and a grade of 3 or above on the tinnitus questionnaire.
Exclusion criteria
-Active inner/middle/external ear pathology as identified in audiological screening exam -Past or current bipolar disorder, schizophrenia. Participants with current anxiety disorders or MDE may be eligible. Use of antidepressants or other anxiolytics at stable doses > 4 weeks is acceptable. -Participants who have a positive urine test for drugs of abuse at screening or pre-administration -Participants with a prior history of seizures; susceptibility to photosensitivity; or a history of allergic skin reactions -Female participants who are or intend to become pregnant or are lactating. -Participants with current active suicidal ideation, assessed using C-SSRS. -Participants with a history of intolerance or allergic reaction to ketamine that may place them at increased risk -Presence of any pacemaker or defibrillator -Presence of any implant in head/neck -Impaired liver/kidney function as identified by blood testing
Outcome results
None listed