Devices, systems and methods for the targeted treatment of movement disorders

Abstract

Devices, systems and methods are provided for the targeted treatment of movement disorders. Typically, the systems and devices are used to stimulate one or more dorsal root ganglia while minimizing or excluding undesired stimulation of other tissues, such as surrounding or nearby tissues, ventral root and portions of the anatomy associated with body regions which are not targeted for treatment. The dorsal root ganglia are utilized in particular due to their specialized role in movement. It is in these areas that sensory fibers are isolated from motor fibers. Sensory fibers are involved in a variety of reflexes that are involved in movement control, and these reflexes can be utilized in the treatment of various movement disorders. Thus, by stimulating sensory fibers in these areas, fundamental reflexes can be affected to lessen the symptoms of movement disorders.

What is claims 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 Parkinson's Disease, Multiple Sclerosis or a Demylenating Movement Disorder. 
     
     
         3 . A method as in  claim 1 , wherein the movement disorder includes Cerebral Palsy, Chorea, Dystonia, Spasm, Tic disorder or Tremor. 
     
     
         4 . 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. 
     
     
         5 . A method as in  claim 4 , 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. 
     
     
         6 . A method as in  claim 5 , wherein the at least one sensory neuron comprises an Ia sensory fiber. 
     
     
         7 . A method as in  claim 5 , wherein the at least one sensory neuron comprises an Ib sensory fiber. 
     
     
         8 . 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. 
     
     
         9 . A method as in  claim 8 , wherein the at least one parameter comprises frequency. 
     
     
         10 . A method as in  claim 9 , wherein the at least one parameter comprises frequency having a value of less than or equal to approximately 100 Hz. 
     
     
         11 . 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. 
     
     
         12 . 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. 
     
     
         13 . A method as in  claim 12 , 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. 
     
     
         14 . A method as in  claim 12 , 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. 
     
     
         15 . 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. 
     
     
         16 . 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. 
     
     
         17 . A method of treating a movement disorder of a patient comprising:
 advancing a sheath having a curved distal end along an epidural space of the patient;   positioning the curved distal end so as to direct a lead advanced therethrough toward a spinal nerve associated with the disorder;   advancing the lead having at least one electrode through the sheath so that the at least one electrode is disposed near the spinal nerve; and   providing stimulation energy to the at least one electrode so as to stimulate at least a portion of the spinal nerve in a manner which reduces a symptom of the movement disorder.   
     
     
         18 . A method as in  claim 16 , wherein the movement disorder includes Parkinson's Disease, Multiple Sclerosis or a Demylenating Movement Disorder.