Background: Neuromodulation

Neuromodulation is the process where nervous system activity is regulated (increased, decreased, sensitized, desensitized) by several classes of neurotransmitter chemicals called neuromodulators, including serotonin, dopamine, acetylcholine, histamine, etc. Neuromodulator chemicals exist not only in the nerve cells (neurons) themselves but in the intercellular chemical "soup" in between the neurons. This intracellular chemistry can therefore act on large groups of neurons at a time. This mass extrasynaptic communication is different from synaptic communication between individual neurons.

Many kinds of physical and mental impairments result from disruptions in the level of neurotransmitters. There is growing theoretical and experimental evidence that many of these conditions might be effectively treated with neuromodulation. Such conditions include motor control impairments affecting balance, posture, gait, speech, and manual dexterity; cognitive disorders of memory, attention, and alertness. Specific diagnoses under investigation include multiple sclerosis (MS), Parkinson’s disease (PD), autism, Alzheimer’s disease, vertigo, depression, and insomnia.

Neuromodulation occurs naturally in the brain but may be enhanced by several factors and techniques:

• Focused, purposeful attention on a task
• Stress
• Psychoactive drugs
• Electrical stimulation of the central nervous system

The latter category, electrical stimulation, has be implemented as several kinds of mostly invasive medical devices such as (1) deep brain stimulation (DBS) via implanted microelectrodes in the basal ganglia, thalamus, and in the midbrain for treatment of Parkinson’s disease and chronic pain; (2) vagus nerve stimulation (VNS) via implanted electrodes for suppression of epileptic seizures and depression; (3) sub-dural implantable stimulators for stroke recovery; and (4) transcranial magnetic stimulation (TMS) of the cerebral cortex for treatment of depression. A recent article in MDDI Magazine summarizes the impact of these technlologies on the field of rehabilitation neurorehabilitation and on the medical device market.

TCNL is developing a new neuromodulation technique called Cranial-Nerve Non-Invasive Neuromodulation (CN-NINM) for treatment of neurological disorders.