Cognitive Function Assessment in a Patient

• US 20130245422A1
• Filed: 06/17/2011
• Published: 09/19/2013
• Est. Priority Date: 06/22/2010
• Status: Active Grant

• Current Assignee: National Research Council Canada
• Original Assignee: National Research Council Canada
• Inventors: Weaver, Donald F., D'arcy, Ryan, Hajra, Sujoy Ghosh, Liu, Careesa, Sculthorpe-Petley, Lauren
• Granted Patent: US 9,339,227 B2
• Time in Patent Office: Days
• US Class Current: 600/409
• CPC Class Codes: A61B 5/165 Evaluating the state of mind, e.g. depression, anxiety
• CPC Class Codes: A61B 5/246 using evoked responses
• CPC Class Codes: A61B 5/316 Modalities, i.e. specific diagnostic methods
• CPC Class Codes: A61B 5/377 using evoked responses
• CPC Class Codes: A61B 5/38 Acoustic or auditory stimuli
• CPC Class Codes: A61B 5/4842 Monitoring progression or stage of a disease
• CPC Class Codes: A61B 5/7246 using correlation, e.g. template matching or determination of similarity

Abstract

A method for analysis of the extent of conscious awareness and likelihood of recovery of a patient includes the steps of applying to the patient a sensory stimulus sequence which is typically auditory; carrying out an EEG to generate waveform signals to record changes in the electromagnetic fields generated by the patient'"'"'s neural activity; using software provided in a processor to process the waveform signals in order to locate waveform peaks, identify the event-related potential (ERP) components obtained in the waveform and to obtain quantitative measures of those components; and using the software to generate and communicate scores indicative of the extent of conscious awareness and likelihood of recovery of the patient.

Claims

1. A method for analysis of the extent of conscious awareness and/or likelihood of recovery of a patient comprising:

applying to the patient a sensory stimulus sequence generated by a stimulator;

while applying the stimulus sequence, carrying out an EEG or MEG on the patient to record waveform signals from an array of sensors on, in, or near the head of the patient;

using software provided in a processor to process the waveform signals in order to locate waveform peaks, identify the evoked responses contained in the waveform and obtain quantitative measures of these evoked responses;

and using the software to generate and communicate scores based on the quantitative measures that are indicative of the extent of conscious awareness and/or likelihood of recovery of the patient.

2. The method according to claim 1 wherein the stimulus sequence is a compressed stimulus sequence that elicits a plurality of evoked responses in a time less than 5 minutes.

3. The method according to claim 1 wherein the stimulus sequence is automated and only requires user input related to patient-identifying information.

4. The method according to claim 1 wherein data processing by the software is automated with no user input required.

5. The method according to claim 1 wherein the software carries out waveform peak detection, the evoked responses identification, and quantitative measurement of the evoked responses of interest automatically with no input from the user.

6. The method according to claim 1 wherein the quantitative measures of the patient'"'"'s evoked responses are automatically compared to normative values from a database.

7. The method according to claim 6 wherein including entering demographic information to improve the specificity of the normative database comparison.

8. The method according to claim 1 wherein the patient'"'"'s results, comprised of evoked response features and scores, are compared to one or more of the patient'"'"'s own results from previous assessments.

10. The method according to claim 1 wherein the sensory stimulus sequence elicits evoked responses related to a plurality of brain functions.

11. The method according to claim 10 wherein the brain functions are comprised of sensory processing, perceptual processing, attention/alerting mechanisms, memory retrieval, and language processing.

12. The method according to claim 10 wherein the brain functions are selected from the group consisting of:

sensory processing, perceptual processing, attention/alerting mechanisms, memory retrieval, and language processing.

13. The method according to claim 12 wherein the evoked responses related to sensory processing are comprised of obligatory sensory evoked responses.

14. The method according to claim 12 wherein the evoked responses related to perceptual processing are comprised of evoked responses that signal the detection of changes in the stimulus sequence.

15. The method according to claim 12 wherein the evoked responses related to attention/alerting mechanisms are comprised of evoked responses that signal attention switching and memory allocation to the presented stimulus.

16. The method according to claim 12 wherein the evoked responses related to memory retrieval are comprised of evoked responses that signal memory-based detection of salient stimulus features.

17. The method according to claim 12 wherein the evoked responses related to language processing are comprised of evoked responses that signal detection that a verbal stimulus violates linguistic expectancies.

34. The method according to claim 1 wherein the software generates scores comprising a diagnostic score, a reliability score, a validity score, and a prognostic score.

35. The method according to claim 34 wherein points in the diagnostic score are allotted based on evoked responses related to a plurality of brain functions.

36. The method according to claim 34 wherein points in the diagnostic score are allotted based on the statistical assessment of differences between quantitative measures of the patient'"'"'s evoked responses and normative values from a database.

38. The method according to any claim 34 wherein points in the prognostic score are allotted based on the statistical relationships between averaged waveform features and historical outcomes of patients diagnosed with the same condition.

9. (canceled)

18-33. -33. (canceled)

37. (canceled)