Assessing Neural State from Action Potentials

Abstract

The neural health or state of a subject is assessed. A recording is obtained of a compound action potential arising in neural tissue of the subject. The recording is processed to determine whether a profile of the recorded compound action potential is anomalous, such as by exhibiting doublets, peak broadening or deformation, or other anomaly. An indication is output regarding the neural state of the subject based on determined anomalies in the recorded compound action potential.

1 . A method of assessing a neural state of a subject, the method comprising:
 obtaining a recording of a compound action potential arising in neural tissue of the subject;   processing the recording to determine whether a profile of the recorded compound action potential is anomalous; and   outputting an indication regarding the neural state of the subject based on determined anomalies in the recorded compound action potential.   
     
     
         2 . The method of  claim 1  wherein the detection of anomalies in the recorded response comprises determining whether more than three peaks exist in the recorded compound action potential. 
     
     
         3 . The method of  claim 1  wherein the detection of anomalies in the recorded response comprises determining whether a peak in the recorded compound action potential is unexpectedly broad. 
     
     
         4 . The method of  claim 1  wherein the detection of anomalies in the recorded response comprises determining whether a peak in the recorded compound action potential has an atypically swift rate of rise. 
     
     
         5 . The method of  claim 1  wherein the detection of anomalies in the recorded response comprises determining whether anomalous frequency components exist in the recorded compound action potential when assessed in the frequency domain. 
     
     
         6 . The method of  claim 1  wherein the detection of anomalies in the recorded response comprises determining a degree of deviation of the recorded compound action potential from a predefined expected response profile and, if the degree of deviation exceeds a predetermined threshold, indicating that the recorded response is anomalous. 
     
     
         7 . The method of  claim 1  wherein the detection of anomalies in the recorded response comprises identifying a locus of neuropathic pain by applying stimuli to first and second neural sites and determining which stimulus gives rise to greatest anomalies in a recorded neural response profile. 
     
     
         8 . The method of  claim 1  when performed intra-operatively to affect effect electrode array implantation site optimisation. 
     
     
         9 . The method of  claim 1  when performed during an implant programming stage in order to optimise electrode selection. 
     
     
         10 . The method of  claim 1  when performed intra-operatively during a sympathectomy procedure, in order to provide an intra-operative progressive indication of efficacy of the sympathectomy. 
     
     
         11 . A method of treating a neural disease, the method comprising:
 ordering or requesting the result of the method of  claim 1 ; and   administering or modifying a therapy in a manner responsive to the ordered result.   
     
     
         12 . A method for determining whether a human patient has neuropathic disease, comprising:
 obtaining a recording of a compound action potential arising in neural tissue of the patient; and   diagnosing the patient as having neuropathic disease if a profile of the recorded compound action potential is anomalous.   
     
     
         13 . A non-transitory computer readable medium for assessing a neural state of a subject, comprising instructions which, when executed by one or more processors, causes performance of the following:
 obtaining a recording of a compound action potential arising in neural tissue of the subject;   processing the recording to determine whether a profile of the recorded compound action potential is anomalous; and   outputting an indication regarding the neural state of the subject based on determined anomalies in the recorded compound action potential.