Non-invasive magnetic or electrical nerve stimulation to treat or prevent autism spectrum disorders and other disorders of psychological development
Devices, systems and methods are disclosed for treating or preventing an autism spectrum disorder, a pervasive developmental disorder, or a disorder of psychological development. The methods comprise transmitting impulses of energy non-invasively to selected nerve fibers, particularly those in a vagus nerve. The nerve stimulation may be used as a behavior conditioning tool, by producing euphoria in an autistic individual. Vagus nerve stimulation is also used to modulate circulating serotonin levels in a pregnant woman so as to reduce the risk of having an autistic child; modulate the levels of growth factors within a child; promote balance of neuronal excitation/inhibition; modulate the activity of abnormal resting state neuronal networks; increase respiratory sinus arrhythmia; and avert episodes of motor stereotypies with the aid of forecasting methods.
1. A method of treating a behavioral disorder in a patient diagnosed therewith, the method comprising:
positioning a contact surface of a housing in contact with an outer skin surface of a neck of the patient, wherein the housing houses a power source, an electrode, and a conductor, wherein the conductor is coupled to the power source and the electrode, and wherein the electrode is coupled to the contact surface;
generating an electric current with the power source; and
transmitting the electric current transcutaneously, as the contact surface is in contact with the outer skin surface of the neck of the patient, through the outer skin surface of the neck of the patient, from the power source through the conductor, the electrode, and the contact surface to a vagus nerve in the patient non-invasively, to generate an electrical impulse at the vagus nerve, wherein the electrical impulse comprises a frequency that modifies the behavioral disorder within the patient.
2. The method of claim 1 , wherein the conductor is a first conductor, wherein the transmitting comprises transmitting the electric current from the electrode, and wherein the transmitting is from the electrode through a second conductor housed within the housing.
3. The method of claim 1 , further comprising:
generating an electric field at or near the housing; and
shaping the electric field such that the electric field is sufficient to modulate the vagus nerve; and
wherein the electric field is not sufficient to substantially modulate a nerve or muscle between the outer skin surface and a target region.
4. The method of claim 1 , wherein the housing comprises a signal generator coupled to the electrode.
5. The method of claim 3 , wherein the electric field at the vagus nerve is from about 10 V/m to about 600 V/m.
6. The method of claim 5 , wherein the electric field is less than 100 V/m.
7. The method of claim 1 , wherein the electrical impulse comprises bursts of pulses with a frequency from about 1 burst per second to about 100 bursts per second.
8. The method of claim 7 , wherein each of the bursts contains from 1 pulse to 20 pulses.
9. The method of claim 7 wherein the pulses are full sinusoidal waves.
10. The method of claim 7 , wherein each of the pulses is from about 100 microseconds to about 1000 microseconds in duration.
11. The method of claim 10 , wherein the duration of a pulse of the pulses within a burst of the bursts is about 200 microseconds, wherein a number of pulses per burst is from 4 to 6, and wherein a number of bursts per second is from 20 to 30.
12. The method of claim 1 further comprising:
generating an electric field at the vagus nerve above a threshold for generating an action potential within an A fiber or a B fiber of the vagus nerve and below a threshold for generating an action potential within a C fiber of the vagus nerve.
13. The method of claim 1 further comprising:
generating an electric field at the vagus nerve above a threshold for generating an action potential within a fiber of the vagus nerve responsible for activating a neural pathway causing a release of an inhibitory neurotransmitter within a brain of the patient.
14. The method of claim 1 , wherein the frequency is from about 10 Hz to about 100 Hz.
15. The method of claim 1 , wherein the electric current is transmitted transcutaneously for a daily time period of less than 24 hours.
16. The method of claim 1 , wherein the housing includes a portion that is insulative, wherein the portion extends about the contact surface.
17. The method of claim 1 , wherein the contact surface includes a dielectric material.
18. A method comprising:
positioning a contact surface of a housing in contact with an outer skin surface of a neck of the patient, wherein the housing houses a power source, an electrode, and a conductor, wherein the conductor is coupled to the power source and the electrode, and wherein the electrode is coupled to the contact surface;
generating an electric current with the power source; and
transmitting the electric current transcutaneously, as the contact surface is in contact with the outer skin surface of the neck of the patient, through the outer skin surface of the neck of the patient, from the power source through the conductor, the electrode, and the contact surface to a vagus nerve in the patient non-invasively, to generate an electrical impulse at the vagus nerve, wherein the electrical impulse comprises a frequency that modifies a neurodegenerative disorder of the patient.