Neurostimulation system

Abstract

Some embodiments of the present invention provide neurostimulation systems and components for selective stimulation and/or neuromodulation of one or more dorsal root ganglia through implantation of an electrode on, in or around a dorsal root ganglia. Some other embodiments of the present invention provide neurostimulation systems adapted for selective neurostimulation of one or more nerve root ganglia as well as techniques for applying neurostimulation to the spinal cord. Still other embodiments of the present invention provide stimulation systems and components for selective stimulation and/or neuromodulation of one or more dorsal root ganglia through implantation of an electrode on, in or around a dorsal root ganglia in combination with a pharmacological agent.

What is claimed is: 
     
         1 . A method of treating a patient having a movement disorder comprising:
 presenting the patient having the movement disorder;   positioning a lead having at least one electrode within the patient so that the at least one electrode is disposed near a target dorsal root ganglion associated with the movement disorder; and   providing stimulation energy to the at least one electrode so as to selectively stimulate at least a portion of the target dorsal root ganglion so as to reduce a symptom of the movement disorder while providing no or imperceptible amounts of stimulation energy directly to a ventral root.   
     
     
         2 . A method as in  claim 1 , wherein the movement disorder includes tremor, dystonia, or spasticity. 
     
     
         3 . A method as in  claim 1 , wherein the target dorsal root ganglion is associated with a reflex arc and wherein providing stimulation energy comprises activating the reflex arc. 
     
     
         4 . A method as in  claim 3 , wherein activating the reflex arc comprises stimulating at least one sensory neuron so as to activate at least one soma of an alpha motor neuron. 
     
     
         5 . A method as in  claim 4 , wherein the at least one sensory neuron comprises an Ia sensory fiber. 
     
     
         6 . A method as in  claim 4 , wherein the at least one sensory neuron comprises an Ib sensory fiber. 
     
     
         7 . A method as in  claim 1 , wherein providing stimulation energy comprises providing a stimulation signal having at least one parameter selected to selectively stimulate the at least a portion of the target dorsal root ganglion so as to reduce a symptom of the movement disorder. 
     
     
         8 . A method as in  claim 7 , wherein the at least one parameter comprises frequency. 
     
     
         9 . A method as in  claim 8 , wherein the at least one parameter comprises frequency having a value of less than or equal to approximately 100 Hz. 
     
     
         10 . A method as in  claim 1 , wherein providing stimulation energy comprises choosing size of the at least one electrode, shape of the at least one electrode, and/or position of the at least one electrode so as to selectively stimulate the at least a portion of the target dorsal root ganglion so as to reduce the symptom of the movement disorder. 
     
     
         11 . A method as in  claim 1 , wherein providing stimulation energy comprises providing stimulation energy in response to at least one sensor configured to sense an indicator of the movement disorder. 
     
     
         12 . A method as in  claim 11 , wherein the indicator comprises an onset of the symptom of the movement disorder, and wherein the stimulation signal is provided to reduce or avoid the onset of the symptom. 
     
     
         13 . A method as in  claim 11 , wherein the indicator comprises a status of the symptom of the movement disorder, and wherein the stimulation signal is provided to treat the symptom in real time. 
     
     
         14 . A method as in  claim 1 , wherein providing stimulation energy comprises providing stimulation energy in response to at least one sensor configured to sense an activity or an activity level of the patient. 
     
     
         15 . A method as in  claim 1 , wherein providing stimulation energy comprises providing stimulation energy in response to at least one sensor configured to detect a position of at least a portion of a body of the patient. 
     
     
         16 . A stimulation system for treating a patient having a movement disorder comprising:
 a lead having at least one electrode, wherein the lead is configured for implantation so as to position at least one of the at least one electrode adjacent a dorsal root ganglion associated with the movement disorder; and   a pulse generator electrically connected to the at least one of the at least one electrode, wherein the pulse generator provides a signal to the at least one of the at least one electrode which stimulates at least a portion of the dorsal root ganglion so as to reduce a symptom of the movement disorder.   
     
     
         17 . A stimulation system as in  claim 16 , wherein the target dorsal root ganglion is associated with a reflex arc and wherein the signal is configured to activate the reflex arc. 
     
     
         18 . A stimulation system as in  claim 17 , wherein activation of the reflex arc comprises stimulation of at least one sensory neuron so as to activate at least one soma of an alpha motor neuron. 
     
     
         19 . A stimulation system as in  claim 18 , wherein the at least one sensory neuron comprises an Ia sensory fiber. 
     
     
         20 . A stimulation system as in  claim 18 , wherein the at least one sensory neuron comprises an Ib sensory fiber. 
     
     
         21 . A stimulation system as in  claim 18 , wherein the at least of the at least one electrode has a size that selectively stimulates the at least one sensory neuron. 
     
     
         22 . A stimulation system as in  claim 18 , wherein the at least of the at least one electrode has a shape that selectively stimulates the at least one sensory neuron. 
     
     
         23 . A stimulation system as in  claim 18 , wherein the signal has at least one parameter that is programmable to selectively stimulate the at least one sensory neuron. 
     
     
         24 . A stimulation system as in  claim 23 , wherein the at least one parameter comprises frequency. 
     
     
         25 . A stimulation system as in  claim 24 , wherein the frequency is programmable with a value up to approximately 100 Hz. 
     
     
         26 . A stimulation system as in  claim 25 , wherein the frequency is programmable with a value up to approximately 50 Hz. 
     
     
         27 . A stimulation system as in  claim 16 , further comprising at least one sensor configured to sense an indicator of the movement disorder. 
     
     
         28 . A system as in  claim 27 , wherein the at least one sensor comprises an accelerometer. 
     
     
         29 . A system as in  claim 27 , wherein the indicator indicates an onset of the symptom of the movement disorder, and wherein the stimulation signal is provided to reduce or avoid the onset of the symptom. 
     
     
         30 . A system as in  claim 27 , wherein the indicator indicates a status of the symptom of the movement disorder, and wherein the stimulation signal is provided to treat the symptom in real time. 
     
     
         31 . A system as in  claim 27 , wherein the indicator indicates a position of at least a portion of a body of the patient. 
     
     
         32 . A system as in  claim 16 , further comprising at least one sensor configured to sense an activity or an activity level of the patient. 
     
     
         33 . A system for treating a patient having a movement disorder, the system comprising:
 a lead having at least one electrode, wherein the lead is configured to be positioned so that at least one of the at least one electrodes is able to stimulate at least a portion of a target dorsal root associated with the movement disorder;   at least one sensor configured to sense a symptom of the movement disorder; and   an implantable pulse generator connectable with the lead, wherein the generator includes electronic circuitry configured to receive information from the at least one sensor and provide a stimulation signal to the lead in response to the sensed symptom of the movement disorder, wherein the stimulation signal has an energy below an energy threshold for stimulating a ventral root associated with the target dorsal root while the lead is so positioned.   
     
     
         34 . A system as in  claim 33 , wherein the at least one sensor senses an onset of the symptom of the movement disorder, and wherein the stimulation signal is provided to reduce or avoid the onset of the symptom. 
     
     
         35 . A system as in  claim 33 , wherein the at least one sensor senses a status of the symptom of the movement disorder, and wherein the stimulation signal is provided to treat the symptom in real time. 
     
     
         36 . A system as in  claim 33 , wherein the at least one sensor senses an activity or an activity level of the patient. 
     
     
         37 . A system as in  claim 33 , wherein the at least one sensor detects a position of at least a portion of a body of the patient.