Using physiological sensor data with an implantable medical device

1. A method for providing an electrical neurostimulation therapy to a neural structure of a patient's body using an implantable medical device (IMD), comprising:

providing a first electrical signal using said implantable medical device;

applying said first electrical signal to said neural structure, wherein the first electrical signal generates a response that comprises at least one of an afferent action potential or an afferent sub-threshold depolarization;

sensing a physiological parameter using an implanted sensor, wherein said physiological parameter includes at least one of a neurotransmitter parameter, a neurotransmitter breakdown product parameter, a neuropeptide parameter, or a glucocorticoid (GC) parameter;

modifying said first electrical signal based upon said sensed physiological parameter to generate a second electrical signal; and

applying said second electrical signal to said neural structure, wherein the second electrical signal generates a response that comprises at least one of the afferent action potential or the afferent sub-threshold depolarization.

2. The method of claim 1 , wherein said neurotransmitter parameter is selected from the group consisting of a norepinephrine concentration, a serotonin concentration and a dopamine concentration.

3. The method of claim 1 , wherein sensing said physiological parameter comprises sensing at least one of a metabolite, a nucleotide parameter, a neuromodulator parameter, a neuromodulator breakdown product parameter, a peptide parameter, a ligand parameter, an amino acid parameter, a hormone parameter, an enzyme parameter, a parameter of a bloodborne substance, a medication parameter, and a drug level in a portion of a patient's body.

4. The method of claim 3 , wherein said neurotransmitter parameter comprises at least one of a dopamine parameter, a serotonin parameter, an acetylcholine parameter, a catecholamine parameter, and a nicotinic parameter.

5. The method of claim 3 , wherein said peptide parameter comprises at least one of a substance P parameter, a neuropeptide Y parameter, a neurokines parameter, a cytokines parameter, a interleukins parameter, and a lymphokines parameter.

6. The method of claim 3 , wherein said enzyme parameter comprises at least one of an adrenoceptor protein kinase parameter, a choline acetyltransferase parameter, and an acetylcholinesterase parameter.

7. The method of claim 3 , wherein said hormone parameter comprises at least one of a glucocorticoid (GC) parameter, a serum cortisol parameter, a cortisol parameter, prostaglandin parameter, a cholecystokinin (CCK) parameter, a orexins parameter, a galinin parameter, a corticotrophin releasing hormone (CRH) parameter, and an adrenocorticotropic hormone (ACTH).

8. The method of claim 3 , wherein the said amino acid parameter comprises at least one of a glutamate parameter, a gamma-aminobutyric acid (GABA) parameter, and a glycine parameter.

9. The method of claim 3 , wherein said nucleotide parameter comprises at least one of a adenosine triphosphate (ATP) parameter and a guanosine triphosphate (GTP) parameter.

10. The method of claim 1 , wherein modifying said first electrical signal based upon said sensed physiological parameter comprises modifying at least one of a current magnitude, a pulse width, a frequency, a polarity, an on-time, and an off-time.

11. The method of claim 1 , further comprising

comparing said sensed physiological parameter with a predetermined threshold; and

modifying said first electrical signal based upon said comparing step.

12. The method of claim 1 , wherein said sensing is performed in response to an event detected by the IMD or in response to an external prompt.

13. The method of claim 1 , wherein said electrical neurostimulation therapy is a therapy for depression.