A Therapy Grounded in Neuroscience Research
MicroTransponder’s approach to treating tinnitus is based on extensive scientific research. This innovative approach pairs a well-known treatment called vagus nerve stimulation with listening to specific tones. Using this method is known as Paired Vagus Nerve Stimulation or Paired VNS™.
How The Serenity® System Works
Tinnitus is generally thought to arise from abnormal neural activity in the brain. Neurons deprived of auditory input begin to respond to surrounding frequencies in the auditory system neurons. This change in neuronal behavior results in a dramatic increase in the number of neurons that respond to a narrow range of frequencies. The neurons also start firing synchronously which is thought to account for some forms of tinnitus. Tinnitus is complex and recent neuroimaging studies show that non-auditory areas (e.g., emotion centers) are also likely to be involved.
MicroTransponder has developed a targeted method to reverse abnormal neuroplastic changes in the brain in order to reduce tinnitus. The Serenity® System pairs tones played through the headphones with stimulation of the vagus nerve in the neck. The tones are tailored to exclude the tinnitus frequency and are specifically chosen to redistribute the responses of auditory cortical neurons and to reduce the abnormal auditory activity that is thought to underlie tinnitus.
One might ask the question, “How can a nerve in the neck cause changes in the brain?” The vagus nerve is unlike any other nerve in the body. It sends important signals to tell the brain what to learn. The vagus nerve sends a signal to the brain to release neurotransmitters such as acetylcholine and norepinephrine. Consistently pairing VNS with tones other than the tinnitus frequency tone, reduces the expanded representation of the tinnitus frequency tone. Over time, the brain learns to ignore the tinnitus frequency tone. Pairing several of these tones (except the tinnitus frequency tone) helped subdue the abnormal hyperactivity and restore the auditory cortex activity back to normal in an animal model of tinnitus. These changes persisted for several weeks after stopping the treatment. This study was published in the journal Nature. (Engineer, 2011)
How VNS Changes The Brain
When paired with tone therapy
Vagus Nerve Stimulated
Implanted lead delivers bursts of electricity that travel up to the brain.
Electric Signal Reaches the Brain
The electric signal passes through the Nucleus Tractus Solitarius (NTS) to 2 distinct brain regions. When these regions receive the electric signal, they release neuromodulators (brain chemicals).
Neurotransmitters Disperse Throughout
The release of transmitters increases the relevance of tones. The resulting brain reorganization and strengthening of the neural connections contributes to the enhanced auditory normalization. These neuromodulators are important for learning and memory and help increase the salience (or relevance) of the tones heard by the patient.
The Therapy In Action
This image below illustrates the therapy in action. Once the implanted device receives a signal from the wireless transmitter, the implanted device emits a small burst of electric stimulation, which travels up the lead to the vagus nerve. The vagus nerve then sends a signal up to the brain, which triggers the release of neurotransmitters, which flow to the auditory cortex and enable the neurons to be reorganized due to neuroplasticity.
The Components of the Serenity® System
The Serenity® System includes four main components.
Model 1000 Paired VNS™ Implantable Pulse Generator
48 mm wide x 62 mm tall x 12 mm thick
Less than 70g
Li CfX – Lithium/Carbon Monofluoride
0 to 3.5 mA
1 to 30 Hz
10 μs to 1000 μs
Model 3000 Paired VNS™ Lead
Outer Material (insulation):
Lead Body Diameter:
100 – 250 Ohms
2mm or 3mm
Model 4000 Paired VNS™ Tinnitus Application and Programming Software (TAPS)
Laptop computer loaded with Tinnitus Application and Programming Software model 4000 (TAPS) is given to each patient to take home.
Model 2000 Paired VNS™ Wireless Transmitter
1. Engineer Navzer, Riley Jonathan, Seale Jonathan, Vrana Will, Shetake Jai, Sudanagunta Sindu, Borland Michael, and Kilgard Michael, “Reversing pathological neural activity using targeted plasticity”, Nature, vol. 470, pp. 101-104, January 2011
2. Kilgard MP1, Merzenich MM, “Cortical map reorganization enabled by nucleus basalis activity”, Science. 1998 Mar 13;279(5357):1714-8.