RecruitingPhase 2ACTRN12621000119897

Effect of ketamine and brain stimulation on tinnitus loudness and distress

Effect of ketamine and concomitant multi-target high definition transcranial electrical stimulation on tinnitus loudness and distress in adults- A feasibility and safety study

Sponsor

Dirk De Ridder

Enrollment

24 participants

Start Date

May 17, 2021

Study Type

Interventional

Conditions

Tinnitus

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.

Eligibility

Sex: Both males and femalesMin Age: 18 YearssMax Age: 70 Yearss

Plain Language Summary

Simplified for easier understanding

Tinnitus — the experience of hearing sounds like ringing, buzzing, or hissing that aren't coming from the outside world — affects millions of people and can significantly disrupt sleep, concentration, and emotional wellbeing. For those most severely affected, tinnitus can feel relentless and debilitating. Despite its impact, very few effective treatments exist. This study is exploring a novel combined approach: using a low dose of ketamine (an anaesthetic agent that can temporarily alter brain activity and plasticity) together with transcranial electrical stimulation (a non-invasive brain stimulation technique) to see whether this combination can reduce tinnitus loudness and distress. The idea is that ketamine may "open a window" of brain flexibility that the electrical stimulation can then use to guide the brain back toward more normal sound processing. Adults aged 18–70 with constant subjective tinnitus of moderate or greater severity may be eligible. People with bipolar disorder or schizophrenia, active suicidal ideation, a history of seizures, pregnancy, impaired liver or kidney function, or who have a pacemaker or implants in the head or neck are excluded. This is a Phase 2 study focused on establishing whether the combination is safe and shows a measurable effect before larger trials are conducted.

This summary was AI-generated to explain the trial in plain language. It is not medical advice. Always discuss eligibility with your doctor before enrolling in a clinical trial.

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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

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.