Treatment of shoulder dysfunction using a percutaneous intramuscular stimulation system

Abstract

A method of treating shoulder dysfunction involves the use of a percutaneous, intramuscular stimulation system. A plurality of intramuscular stimulation electrodes are implanted directly into select shoulder muscles of a patient who has suffered a disruption of the central nervous system such as a stroke, traumatic brain injury, spinal cord injury or cerebral palsy. An external microprocessor based multi-channel stimulation pulse train generator is used for generating select electrical stimulation pulse train signals. A plurality of insulated electrode leads percutaneously, electrically interconnect the plurality of intramuscular stimulation electrodes to the external stimulation pulse train generator, respectively. Stimulation pulse train parameters for each of the stimulation pulse train output channels are selected independently of the other channels. The shoulder is evaluated for subluxation in more than one dimension. More than one muscle or muscle group is simultaneously subjected to a pulse train dosage. Preferably, the at least two dosages are delivered asynchronously to two muscle groups comprising the supraspinatus in combination with the middle deltoid, and the trapezious in combination with the posterior deltoid.

We claim:  
     
         1 . A method of stimulating select shoulder muscle tissue of a patient for the treatment of shoulder dysfunction comprising: 
 implanting at least one electrode into each of a first and a second muscle group of the patient, the first muscle group comprising the supraspinatus in combination with the middle deltoid, and the second muscle group comprising the trapezious in combination with the posterior deltoid;    programming a stimulation pulse generator in communication with said electrodes; and    addressing the electrode with the pulse train generator to stimulate the muscle tissues of the first and second muscle groups.    
     
     
         2 . A method of stimulating shoulder select muscle tissue as set forth in  claim 1 , wherein said stimulation pulse train generator is programmed with a stimulation pulse train pattern including at least one stimulation cycle defining a stimulation pulse train envelope said pulse train envelopes is defined by at least a ramp-up phase of a first select duration in which the pulses of a stimulus pulse train progressively increase in charge, a hold phase of a second select duration in which the pulses of the stimulus pulse train are substantially constant charge, and a ramp-down phase of a third select duration in which the pulses of the stimulus pulse train progressively decrease in charge.  
     
     
         3 . A method of stimulating select shoulder muscle tissue as set forth in  claim 2 , wherein said implanting step comprises implanting a plurality of intramuscular electrodes into select muscle tissue of the patient; 
 electrically connecting said plurality of intramuscular electrodes implanted into patient muscle tissue to said plurality of output channels, respectively; and,    generating stimulation pulse train signals with said generator for each of said plurality of stimulation output channels so that said select muscle tissue of said patient is stimulated in accordance with said at least a first and a second stimulation cycle and wherein said select muscle tissue is at least two different muscle tissues.    
     
     
         4 . A method of stimulating select shoulder muscle tissue as set forth in  claim 3 , wherein at least two stimulation pulse train signals are generated to form at least two stimulation cycles which are not equal at every point in time.  
     
     
         5 . The method of stimulating select shoulder muscle tissue of a patient as set forth in  claim 1 , wherein said step of implanting a plurality of intramuscular electrodes into patient muscle tissue includes implanting up to eight intramuscular electrodes.  
     
     
         6 . The method of stimulating select shoulder muscle tissue of a patient as set forth in  claim 1 , which further includes as a first step the step of evaluation of the shoulder area for subluxation of the shoulder of the patient to select muscle for treatment.  
     
     
         7 . The method of stimulating select shoulder muscle tissue of a patient as set forth in  claim 6 , wherein the patient is hemiplegic and the method further includes a comparison of the shoulder involving the select muscle tissue with the other shoulder of the patient.  
     
     
         8 . The method of stimulating select shoulder muscle tissue of a patient as set forth in  claim 1 , wherein said pulse train signals are generated so as to provide for stimulation for at least one hour every day for a period of treatment.  
     
     
         9 . The method of stimulating select shoulder muscle tissue of a patient as set forth in  claim 6 , wherein said evaluation includes radiographic assessment in at least two planes selected from the group comprising anterior/posterior; medial/lateral, and superior/inferior.  
     
     
         10 . The method of stimulating select muscle tissue of a patient as set forth in  claim 9 , wherein said period of treatment is at least one week.  
     
     
         11 . A method of stimulating select shoulder muscle tissue of a patient for the treatment of shoulder dysfunction comprising: 
 implanting at least one electrode into each of a first muscle group and a second muscle group of the patient;    programming a stimulation pulse generator in communication with said electrode with at least a first and a second stimulation pulse train pattern each including at least one stimulation cycle defining a stimulation pulse train envelope; and    addressing each of the electrodes with the pulse train generator to stimulate the muscle tissue of each muscle group.    
     
     
         12 . A method of stimulating shoulder select muscle tissue as set forth in  claim 11 , wherein each of said pulse train envelopes is defined by at least a ramp-up phase of a first select duration in which the pulses of a stimulus pulse train progressively increase in charge, a hold phase of a second select duration in which the pulses of the stimulus pulse train are substantially constant charge, and a ramp-down phase of a third select duration in which the pulses of the stimulus pulse train progressively decrease in charge.  
     
     
         13 . The method of stimulating select shoulder muscle tissue of a patient as set forth in  claim 11 , wherein said step of implanting a plurality of intramuscular electrodes into patient muscle tissue includes implanting up to eight intramuscular electrodes.  
     
     
         14 . The method of stimulating select shoulder muscle tissue of a patient as set forth in  claim 13 , which further includes as a first step the step of evaluation of the shoulder area for subluxation of the shoulder of the patient to select muscle for treatment.  
     
     
         15 . The method of stimulating select shoulder muscle tissue of a patient as set forth in  claim 14 , wherein the patient is hemiplegic and method further includes a comparison of the shoulder involving the select muscle tissue with the other shoulder of the patient.  
     
     
         16 . The method of stimulating select shoulder muscle tissue of a patient as set forth in  claim 12 , wherein said ramp-up phase duration is from about 2 to about 8 seconds, said hold phase duration is from about 5 to about 15 seconds, and said ramp-down phase duration is from about 2 to about 8 seconds.  
     
     
         17 . The method of stimulating select shoulder muscle tissue of a patient as set forth in  claim 16 , wherein said ramp-up phase duration is from about 5±1 seconds, said hold phase duration is from about 10±2 seconds, and said ramp-down phase duration is from about 5±1 seconds.  
     
     
         18 . The method of stimulating select shoulder muscle tissue of a patient as set forth in  claim 11 , wherein said stimulation cycle includes a stimulation phase and a rest phase, and said first muscle group is subjected to stimulation from said stimulation phase when said second muscle group is subjected to said rest phase.  
     
     
         19 . The method of stimulating select shoulder muscle tissue of a patient as set forth in  claim 18 , wherein said pulse train signals are generated so as to provide for stimulation for at least one hour every day for a period of treatment.  
     
     
         20 . The method of stimulating select shoulder muscle tissue of a patient as set forth in  claim 19 , wherein said evaluation includes radiographic assessment in at least two planes selected from the group comprising anterior/posterior; medial/lateral, and superior/inferior.  
     
     
         21 . The method of stimulating select muscle tissue of a patient as set forth in  claim 20 , wherein said period of treatment is at least one week.  
     
     
         22 . A system for stimulating shoulder muscle tissue for the treatment of subluxation comprising: 
 an electrode assembly adapted to be located to affect stimulation of shoulder muscle tissue, and    a stimulation pulse generator in communication the electrode assembly including a processing element programmed with at least one stimulation pulse train pattern including at least one stimulation cycle defining a stimulation pulse train envelope, and an output element adapted to address the electrode assembly with the at least one stimulation pulse train pattern to stimulate the muscle tissue and thereby treat subluxation.    
     
     
         23 . A system according to  claim 22   wherein each of said pulse train envelopes is defined by at least a ramp-up phase of a first select duration in which the pulses of a stimulus pulse train progressively increase in charge, a hold phase of a second select duration in which the pulses of the stimulus pulse train are substantially constant charge, and a ramp-down phase of a third select duration in which the pulses of the stimulus pulse train progressively decrease in charge.    
     
     
         24 . A system according to  claim 22   wherein the electrode assembly includes at least two intramuscular electrodes adapted to be implanted in at least two different shoulder muscle groups, and    wherein the output element addresses each of the at least two intramuscular electrodes through a separate output channel.    
     
     
         25 . A system according to  claim 24   wherein the processing element is programmed with at least two stimulation pulse train signals to form at least two stimulation cycles which are no equal at every point in time.    
     
     
         26 . A system according to  claim 22   wherein the processing element is programmed to provide stimulation for at least one hour every day for a period of treatment.    
     
     
         27 . A system according to  claim 22   wherein the stimulation pulse train envelope is a balanced charge wave form.    
     
     
         28 . A system for stimulating shoulder muscle tissue for the treatment of shoulder dysfunction comprising: 
 a first electrode assembly adapted to be located in a first shoulder muscle group to affect muscle stimulation,    a second electrode assembly adapted to be located in a second shoulder muscle group different than the first shoulder muscle group to affect muscle stimulation,    a stimulation pulse generator in communication the first and second electrode assemblies including a processing element programmed with at least one stimulation pulse pattern, and an output element adapted to address the first and second electrode assemblies with the at least one stimulation pulse pattern to stimulate the first and second muscle tissue groups.    
     
     
         29 . A system according to  claim 28   wherein the processing element is programmed with a stimulation pulse train pattern including at least one stimulation cycle defining a stimulation pulse train envelope defined by at least a ramp-up phase of a first select duration in which the pulses of a stimulus pulse train pattern progressively increase in charge, a hold phase of a second select duration in which the pulses of the stimulus pulse train pattern are substantially constant charge, and a ramp-down phase of a third select duration in which the pulses of the stimulus pulse train pattern progressively decrease in charge.    
     
     
         30 . A system according to  claim 28   wherein the processing element is programmed to generate a first stimulation cycle and a second stimulation cycle, and    wherein the output element addresses the first electrode assembly with the first stimulation cycle and addressed the second electrode assembly with the second stimulation cycle.    
     
     
         31 . A system according to  claim 30   wherein the first and second stimulation cycles are not the same at every point in time.    
     
     
         32 . A system according to  claim 30   wherein the first and second stimulation cycles each includes a pulse train envelope.    
     
     
         33 . A system according to  claim 32   wherein the pulse train envelopes of the first and second stimulation cycles differ.    
     
     
         34 . A system according to  claim 32   wherein at least one of the pulse train envelope is defined by at least a ramp-up phase of a first select duration in which the pulses progressively increase in charge, a hold phase of a second select duration in which the pulses are substantially constant charge, and a ramp-down phase of a third select duration in which the pulses progressively decrease in charge.    
     
     
         35 . A system according to  claim 30   wherein the each stimulation cycle includes a stimulation phase and a rest phase, and    wherein the output element addresses the first electrode assembly with a rest phase while addressing the second electrode assembly with a stimulation phase, and vice versa.    
     
     
         36 . A system according to  claim 28   wherein the processing element is programmed to provide stimulation for at least one hour every day for a period of treatment.