Contingent cardio-protection for epilepsy patients
Disclosed are methods and systems for treating epilepsy by stimulating a main trunk of a vagus nerve, or a left vagus nerve, when the patient has had no seizure or a seizure that is not characterized by cardiac changes such as an increase in heart rate, and stimulating a cardiac branch of a vagus nerve, or a right vagus nerve, when the patient has had a seizure characterized by cardiac changes such as a heart rate increase.
1. A method of controlling a heart rate of an epilepsy patient comprising:
sensing a kinetic signal of the epilepsy patient;
analyzing via one or more processors the kinetic signal to determine at least one kinetic index;
receiving a cardiac signal of the epilepsy patient;
analyzing via the one or more processors the cardiac signal to determine the epilepsy patient's heart rate;
determining if the epilepsy patient's heart rate is commensurate with the at least one kinetic index based on a comparison of the at least one kinetic index to the epilepsy patient's heart rate; and
applying an electrical signal to a vagus nerve of the epilepsy patient, based on a determination that the epilepsy patient's heart rate is not commensurate with the at least one kinetic index.
2. The method of claim 1 , wherein the at least one kinetic index comprises at least one of an activity level or an activity type of the epilepsy patient based on the kinetic signal, and wherein determining if the heart rate is commensurate with the at least one kinetic index comprises determining if the heart rate is commensurate with the at least one of the activity level or the activity type.
3. The method of claim 1 , wherein determining if the epilepsy patient's heart rate is commensurate with the at least one kinetic index comprises determining if the heart rate exceeds a level that is commensurate with the at least one kinetic index,
and wherein applying the electrical signal to the vagus nerve comprises applying a therapeutic electrical signal to at least one of a main trunk of the vagus nerve and a cardiac branch of the vagus nerve to lower the epilepsy patient's heart rate to a rate that is commensurate with the at least one kinetic index.
4. The method of claim 1 , wherein determining if the epilepsy patient's heart rate is commensurate with the at least one kinetic index comprises determining if the heart rate is below a level that is commensurate with the at least one kinetic index,
and wherein applying an electrical signal to the vagus nerve comprises applying a pulsed electrical signal that blocks action potential conduction on at least one of a main trunk of the vagus nerve and a cardiac branch of the vagus nerve, to increase the epilepsy patient's heart rate to a rate that is commensurate with the at least one kinetic index.
5. The method of claim 1 , wherein determining if the epilepsy patient's heart rate is commensurate with the at least one kinetic index comprises determining if the epilepsy patient has had an epileptic seizure.
6. The method of claim 1 , further comprising
determining if applying the electrical signal results in an adverse effect, and
changing at least one parameter of the electrical signal in response to determining that applying the electrical signal results in the adverse effect.
7. The method of claim 6 , further comprising
discontinuing the electrical signal if the adverse effect is severe or if the change in at least one stimulation parameter does not reverse the adverse effect.
8. The method of claim 7 , further comprising
further analyzing the cardiac signal to determine a second heart rate after applying the electrical signal to the vagus nerve; and
discontinuing the electrical signal based on at least one of
reaching a programmed on-time limit for a first electrical signal, and
determining that a second heart rate is a rate commensurate with the kinetic signal.
9. The method of claim 1 , wherein the at least one kinetic index is based on an output of one of an accelerometer, an EKG, or a force of movement measuring device.